rapid photometric methods for determining rubber and...
TRANSCRIPT
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MICROCOPY RESOL JTION TEST CHART MICROCOPY RESOLUTION TEST CHART NATIONAL BUREAU 01 STANDARDS-J963-A NATIONAL BUREAU Of STANDARDS-1963-A
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Technical Bulletin No 920 Altllst 1946bull
Rapid Photonletric Nlethods for Determinshying Rubber and Resins in Guayule Tissue and Ruhber in Crude-Rubher Products 1
By HA~[[rTl~ P IRAlB
Prilldpal phlsit)l()li~t Iprdl GWllllr Rcv(I11t Pru]-t BUNtlll fit 1lllllt l1rlll~ tlll Soils (llul Agri(IlUllral Ellgiltcctill[Jbull bullJ [J1j(ult lllfil RIU(cl ltlmiHistration
CONTEXTS
Pal I Pa~e
bull Introduction_ _ l ExpNimental restllt-ContillUP(Procedures ____________ bull __ 4 Time of tauding after rubber
Preparation of ample5 ______ _ 4 or rein precipitationbull _ Xii effect of resins in olution __Reagents for rubber analpis_ -j El-traction temperatllTe andReagents for re5ins analyis __ _ 6 tinle ___ ________________ _
Special equipment for rubber Rubber and reins standards__and resins analyi __ bull __ _ 6~ Rubber and re~ins calibrationCleaning glasware __ bull _____ _ ) CllryeS __________ ______ _- 30 Rubber (cnoutchouc calibra- ensitivity of methods ______ _ 32~ tion cun-es _____ ___ _ __ 10 Error coniderations________ _ 32- Resinirinlibrrtion curves ___ _ 12 Correction for insoluble residue 33
~l ~rocectdre for ruhber analyi_ 14 Reroyerv of rubher and resins ~ IDProcelt3lre for reins analy~i __ 15 a~ldeci to extract of guayulc
t~~ue __ __ _- 33 ~ c calculation
~Phot~tric instruments recshyCornpariion of photometric
~ of ~lts____________ ___ _ and morlified Spence-Caldshy om~nded and 15~ well method of rt1bbergxperiInamptal reuki __________ 11 Hi ________________ _analy~b
1- ~repamtion of ample5 __ _ n- lti Yariation of ~inQle deterrnina-34
e-3olvenJl----- --- __ -_ - - - __ 20 tions froUl rheir mpan_____ _ ~ 34 -~ Precipi-ants _ __ ____ __ __ _ 20 Rubher 3nalvis in crudeshy ProtecTIve colloidL _________ _ 21 rnhber prodtlct8 ________ _ 36Summary___________ _______ _Eliminating errors due to ex- 36
traneous colors_____ _ __ _ 21 Literature cited _____ bull ___ bull __ _ 37
In order to nehie-e the maximnm prozre5- ill leelllCh on the phyishyology of guayule (Parthenillm ilrgt-ntaiulll A_ Gray) it is imperath-e
bull gt Submitted for publication January 3 10-6 bull Credit is due Beatriee K Dewald main scientific aillp fill asistancp in the
laboratory fl0403s-4amp-1
2 TECHNICAL BULLElIN 920 U S DEP~ OF AGRICULTURE
to have rapid methods for the determination of rubbel and resinsl r as well as the already available llLpid analy6cal procedures for the
other plant constituents In this bulletin aee described new rapid photometric methods for the analysis of Tubber and resins in small samples of guayule and of rubber in tissues of other plants and in crudeshy bull rubber products
The classical method of Spence alld Caldwell (5) 4 is cOJ11monly used for the determination of rubbll Ilnd resins in plant tissuC Duplicate 5-gm samples iue used Vater solubles lIl( fiest lel1lOVld by boiling in I-percent sulfuric acid for a hours the extLart is tlHn tlItuen(gt(l for 3 hours and leached fo1 1 houls Ill( slI11ples HI( l1(xt (xtladed in It Teflux-type apparatus wi th HCCtOl1t for]2 hour~ to obtai n the acetolH extract finally they arB extradNl ~il h JeIlZlIe ill the sllmc type of apparatus for at least Hi houls AJtelii 1111 oi l Ol-pClcent solutton of dimethyl-p-phenylenec1iamine has 1lll1l added to the benzene exshytract the benzene is (Jvaporitld and the lublJC1 is weighed
Employees of the Intercontinental Rubbrr Co fi and of the Eastern Research Laboratory Bureau of AgliClIltlIlHl and Industrial Chemshyish and Holmes and Haais 7 lmyr uHrdmodific(l ~pence-Calc1well procedures Acc~rding to the Holmes-Haasis modification wl1ich is used in cershy
tain comparisons (1isCussNl in I-his bulletin thC size of the sample is reduced to 3 to 4 gm water solublcs are extractrd by 2-percent (inshystead of I-percent) sulfuriC teid for Ph hours (instCud of 3) the subshysequent autochvin~ is for 112 hours (i mttalt1 of 3) and the leaching for 1 hour (instead of 3) Samples [lee twn (xtractp(l for R hOllrs (inshystead of 12) with acetone in a rpftnx-tYLJC apparatus to obtain the Hceshy bulltone extract they are finally cxtraetplt in the san1( type of apparatus for 16 hours middotith bCllZ(ne AftCr 1 1111 of a Oo-pcrcCnt solution of p~lellyl-a-naphthylall1ine (instead of ) 1111 of a Ol-pclcent solution of chmethyl-p-phenylenediamine) has b((1 added to the b(ll1Zene extract the benzene is eyaporated und the IIlbber wi~hed This modified Spence-Caldwell method if referred to in thC comparisons with the present mettocU
bull The term reinH as used hpl(in r(Cel tn tIl( lwJion of the l1(et-one 0) Ilcetonyl acetone-cellosoYe 3-7 extTnrt of glll1Yl11e tiue tha I-is pr(ci]litatNl by O5-percent H2S0 in H 20 This preeipitate reprei(nls n mixture 0[ gt(Y(Ia subslanclS An inventory of whnt is kIlOIlIli)ollt IIli fmerioll if gh(n (Ill IlllgC 21 Frolll n physishyological stllll(l(1oinl this fllletion is cougtidN((l at (1refent 11 IIIl IIp(11oximnte measshyure cf the contents of the relill cannl and nny relill that mar be irw]uded in the cells The wo)(1 rCsins without (]uotflfion mark i~ 1Is((1 ill tllP t(xt in this sense
Hfllic nUlllh(I~ ill (1IlI(lltlWlClt 1C(ll to Litllnture (itld p3 bull InfOllIlation in the f1(l of th( flIlina (lhi8ion I11tll(011tln(111111 nllhlle Co
now thC property of till l K DlPIl Iment (If grienltulp bull ANALYTICAl S~CTIOX ]~AIImN RI~TOXI LAllOlkTonY Inonnllus FOR rlI~
ANALYSIS OF lIUT1IJER-m1lTNG r~TS 10 THEIR OERTETlIROIIU(1S [Unpublished] T HOL)[ES R L lind HALSIS F T NOTES 0 rlIE SIENCE-CL)WElL )[ETHOD 01
RUBBER ANATYSIS But Plaut Indus SOils i1nd Agl Engin ~1Xlt Guuyule Res Ploj Rpt [Ullpllb1ishe(11
bull Credit is clue R L Holll1PS Fr HtI~ilt lllHi theil assitnnts ill the ubber laboratory Special Guarulp ResetuCh PlOjPCt Sul I111 S Calif fOl making the bull rubber lind resins detelminu lions hr th( Illo(lifieltl Spen((middotCuldwlll method for use in the comparisons recorded
3
bull
bull
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RAPID PHOTOMETRIC DETERiHNArIOX OF RCBBER AND RESINS
Cox 9 proposed a turbidimetric method for rubber ana lysis AcshycordinO to this l)rocedure 5 Om of ground material is extlflcted with 100 mtof benzene for 15 mil~ltes in ri lVaring ble11(le1 or with comtant sha~ing the sltperllatant liquid is clarifieltl ~Y cent~ipoundllp-inJ~ and is maUe up to a lOU-lUI volume The rubber In i)-Ill alIquots ]s preCIpshyitated by the addition of 1 m1 of carbon tetrachloride plus ~o m1 of acetone Rubberis determined turbidimetrieaHv on aliqnots of the extract in a Fishpoundr 155-volt a c model elertlopliotomEtEL fitted with a 52) 13 reE11 filttLmiddot T011pound an(llildlllan10 pLopoeltl a 1l1OdifieLl form of the Cox method O3-gm saInpl(s of the groun(l material are extraettd oWllliht ith 11l Ill of b(I1ZellP the extrHt j (~larified bv centrifl1ing alle dEcn n tNl into a )-l1 1 youl11et ri( tlac awl tlie rEsicluE i Extractp(l thrN a1ltiitiollal time with )-1l1Ipmtions of benzene in each cas( eentriinp-inp- al1d (((calltill) of thl liquid which is added to the oriinal lxtlnet follow ftPL the lxtlnet is made up to a 15-m1 volun1e ~-Ill1 aliquot tlLl piPNtPltl into) Ill of aeetone in test-tube cuvett(s till leultillg lubhl1 ~ll-pPlbion i III ixP(l 111(1 the amount of lubbpr is (lltellllined J tll IPHIiI1 of cnttereclliht Oll n Coleman pleetronh pitotoll1orometer
The aboYpound-l1lelltioIlPd II()(Eltlllrp~ for Lubbpl nIlflly-is W(LP tet((l in the writers lahoratol hut (lid not gin prp(ip alll acculatp llsnts nppalently bp(auie of tlll natulp of tIl( rubhpl ohEllts nn(l precipshyitant used thpoundgt ClIOI cHup(lln (xtralle()lI~ eolor in tIlt Extract and the failure to contto) llflir-iClltl~middot the (hnnrl ill tlIP pilotolUCtlie 1etlllshyinS of lllbhfl in (olloi(lal solutioll Oil talHlill
ppalently 110 photomltlie IlIPth()rl fOL jeill analy-i- in plant tissue hns been reported
The presCl1t photolllPtli( lllPthod fc)J ann Iyi of rlthhlr and resins are based on the folloillf pLineiplf III (~lilH1ill tIl( properly ddecl tisslle to the rpoundgtltuile(l (1(1(( of fhHIHS to pelmit flnantitatiw extraction of rubber or 1(in f11 l1~ill o)-YlwltE(l ~()lVPllt with relatively hip-h boilinf points (115 to 230I C J al011p orin mixture that permit thr rlpld Ixtlactioll of 1llhber or [pil1 in 2fl to ~(l minutes at relatiwy hirh telHppratHlt 11j to 110 0 I (31 precipshyitating the rubbEl or [eill front ali(luot of tht olutioll- by mean of suitable rrecipitant I-ll making photOUlPtlic lpadil1gs of pershy(enta~e of light ttnnslllittarHe afteL rubhel OL resin pretipitation at 11 wave lenp-th that eliminate tht (ImI dlle to extLalJPOll (oloL (the determinatioJl relyinp- on the (lEnlopment of t uniforlll turbi(lity (1 ppl-() miller than a color for pllrpos(s of amtLY-l J I) e(uriLl this uLlifoLm tlll)idity 01 reqnill(l clerEe ()pound plp(i-lm by makin the photometric rEac1ings at stamlinf rlm( I har arl hald on the (oiweLlshytlation of rubber 01 l(in preeipiratetl ThE rrlatiou of COIwentmshytion ~)f nlecipitat~ltl rllh~pl Ot Ieins to -tnhiliry of photOlllEtrir leltclshymp-s Io dtnloped III tlptatl Oil pn14 to 11)
In rubber tlnalyis the u~e of the (lxYrfnntEll lhpnt wirh hili(L boiJing point~ eliminlltP rill II( of thr hirb1y n)latilr and toxie lWllshy
bull (ox L C A TIRBIOt(ETRfC l(~rHI)O fnR THE ~-lY5r 1F 11-1 )[ATFRULS FOR RDJIlER Rubtwr REftT( (OlTl Rpt rCnpllbllhlL 1
Jo~ES E bull T nnd YILD)L~ R G JLPID SE)([~rrlRo ~(~TlIOD FOR THE A~_Lshyysrs OFROIDER n PL-iT lUTERrU Bur Planr Inrlufbull ~oih and Agr Eogin Dibull Rubber Plant Invesr Rpt rtnpllblishErl J
4 TECHNICAL BULLETIN )20 U S DEPl Olr AGRICUlllURE
zene The solvent 11ethy1 isobutyl ketone on wl1iel~ most of the experllnental wod WJth the lubb(r ll1(tlwd Ii bas(d lH reported as nomiddotntoxic (9)
In phsiological experiments tll( alllount of nilable 1l1aietial is often vely low and lubbel ])(ll((ntats J)(low 1 PlI(Cnt- atl lIot uncomshymon Henep the 1(((1 fol Illllltl)tis lqually He(Ulntl JOt nil rnng(s of Lubber contents and rcql1iling tt 111inill1ll111 of plant lllai(lrialis emiddoti(lent It- j5 b(Iic(d that tIl( Illtmiddothods dtgt-(liiJld Oil pn(s middotl to 10 mept these specjficati(l1s In tHhlitlOll the IJl(JtClt111I(S dlS(Libcd t1wle aLC relashytively rflpid
Although these J1wthods welt ltlPlloped primneily fOI llse in rosea1eh on glHl~rule pJ~ysi()loy Ih(y hmiddot( widI ~ppli(nti()I~ riley han b(en uld til lOlltllH 1Jtul( llIlgtbpI alit l(SIIlS tlnalslgt HI an eqnal basi with the 1H0difi~lt1 SpeJlCl-Cnld(lIlllcthod in the gCIlPrul rubber labomtory Special Guayuil Rpsearclt Project since August 1043 They should alo he of ntllll in dptllIIIinin lllbbel lllldlcsins in guaYlll( bre(dillg mn(Nial aIHl iJl ollicl it ud its foJ wh iell plnnt lllatllial is lit II it((l
ROCEDUHES
PnEIAIIATION OF SAMPLES
The details of prepalation of tll( tissllc ~ulllplc are hpt (onslant tluouhollt any 1) rtiellla I I(s(allh Ploj((t Vhl11 portiolls of the same samplps are tnlwll foJ eh(mienl al1alJses h(sic1cs Il1blgtlI anc1lesins the plnnt parts alc dJi(ld ithollt PI(tlpatmlnt Yhlthpr Slpalflte mmples arc talnl1 for the otlwl analyses 01 tllP iolp pl1lpose i obtninshyi ng an estimate of the totrtllllbbel and Iesi ns tlw pIa nls Ol plnnt pnrts arp pa((d in hoiling ralpl fo f minlltps (paJJoiIN])l1 and uny lCfiyes slill adhering to tIl( SIPIlIS alc 1llTlowd hv ta pping on a table top
The plnnts 01 plant pUltS nlp sllbslqucntly coarsely ground in a Viley or otillI suitablp mill and drip to pc1(Cnt or iPssmoisture in a IllcChnnieal ltomNtion onn at (joj C l)(OIp thp final grinding A drying period of nt least 2-1 IlOu1s is IPqu iLN Ill( dried tissue is then grollnd in a ltnml11t1 mill (n llntil it pasls throllgh It 2- or 25shy111m SC]pe1 Th( mill is prodded with a ground win to Iemove stalic elpctricity fronl til slmpl BltWll1l snmplpsit is (]ennNl thoroughly by blowing with eompllsHd niL The ground samplps are tOl((l in ahtight contaimIs Viele-mouth
bottles Hh metnl 01 plastic SClPW tops are 1I0sI COlwcn ilnl for this purpose
8i11(( the J(lsnltsin mot physio]ogi(1I1 PXIlltlinPllfs nre Ixplessed 011 the basis of tllP d I wpight of hI otigi nil I Sit 1I1pJt (II)(d to (onsiant weight at 100 C it is ltifirable to (SPIPS thl finnl IlIbhCt awl 1(ins contents on tlw sn Illl basis A (OlIP( iOll fad Ol i- t h(J(fote d(I(Ishymi1Nl Oil the (inply glOlll1(l 1lotol1ghly mispel sample bY dtying snlnll rluplieate SllbSHlllphs t 1 to 2 gnl) 101 R houts at IO(Fin In ordinary
U rhp plncO( of Pl Iboiling- g-narllllt 1111111 fOI IPIJ1f1yn I of 1(1Y was dyploppd h (mplop of th IntfI(ul1titwlltai Rllhllpl ro CL r (lI(III ]Jxj1lillHntmiddot ~-24) ~PJlt 15 1928) lind nlo IlJlPlirc1 by otlWl flJIployp(s ill Intpl YlI1l~s rhis was nS(PItaiJ1(1(1 from til( fi)(~ oC Ill IntllOIltilllllal HnbbPJ (0 now fill 1110))shyclty of till U S DppuLtIncnt of Agrlcl1itULe
bull
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RAPID PHOlOMErRIC DETERlrINATION or RGBBER AND RESIN) 5
drying oyen hen the samples are yery snlall minimum umounts at tissue in wry small weighing bottles t35 CIll high and 22 em in diameter) are usee to (Ol1SNTe ti-ue The sumples pound01 analysis are then w(iglwd Ollt Oil tlil llalis of (onsl Ltlt dry weight at 1000 by using the factor fol 1l10isttllC COIlP(fion
lJAGE~TS FOH RtBBEH AlALYSIS
In a l111lllbpl of eases in tllis -(cti(Jll nnd the Olle on Heagents fotmiddot HesinLllltlvsi It(llllilttl-gltlde dlllllieal whielt were the best obtainshyabll during tIl Wlll])(gtlio(L fLtP indklttd These proed adequate but wllln b(itleL glatils HIe inailahle tIll) (HII he cl1(gt(ke(l to dcleLlnine lny adntntugts of lIbsl ituting p gllltlps rill nbbpl and rtsins soh-enls HIC kept ill glas--ioPPlllll bot Lt
Sollenl~-Methyljs()lJlItyl kl~t(JII(gt t(hnicalgrllll lIbOIl amp Cmbide Chemshylenls COlp is (nUlply latiII(tOIY fol 1I1ltuIHI 11IblJl1 lt is IPportell us appalshylutlr Ilontoxie UI) Although it has thp (IHIIl(fplJ it IWOIll ollor this is leSS IllOIlOUIl(ld than that of othlr IHIOIHs ((Ilsfnuls fol this lIud other rubbel -lIlrellts art given in tuble 1
lAlllE l-Propumiddotfirlr of Hfulr drubIeI olld I(~ills SOllCllts completely soIlvie in 9JpccI)Jt cUtawt
olu billt r (reshyHnilmiddot lation to weight mg ~yenI~NI~ I at (J0 C)point ~1hSolvent FOrl1uh (Ill llOlnl (IIlII(l
lUIIl ruhber 01middot Wut~r llg nlI in lusomiddot
wlter vent
Hubber sohcut c c Benzene l _ elf ~nl ILU olulole ~[NhYI iobutyl k CHltlH(JIC(J(H II 23V do
tonl LNbyllHlfllyl ketOlw (If c1I3IUIllUmiddotoCli lW r 4S U _ do 43 1 1 Diiohtllyl kNone ICH([JemiddotJjlWmiddotU(ll(I1 11 fln 010 06 45 Butyl nCltllt~ (I1roeJ(I1 12fi3 a7~ do fiS 12 ~Iethyl amyl atNnW (ljCO(j(lH1 (Jl(J1lIJ 1 IIi 3 131 lt10 13 1lS Ethylene ~IH-oI dimiddot CjlJO( HtI1O(fh _ 121 I 3J () 110 210 3
rtllyl Nlllr ~middothutyl (ther (ThO Ih 112 37 ~ tlo 03 19
Rcsins oh-cuIsACNone I _ clI C()( If I -~middotI lrNiuhll I()() 100 cetonylnclonp Cn (middoto(JJcHlt()(I WI I ~H tlu UKI llJO EthylD( glycol mollmiddot CHUCUCII0H 13[1 rl2 _10 1(10 100
oNhyl Nher (((lIoshyFohc)
Diethylene gly(ul 3u 7 1111 ~flo lOU 100 mOllohutyl Nlltr Ibmyl carbitol
I fncllulbullbull j lor rOllp3rison lnly
RIlJJIIJ1J( (illituliIlQ SOIIIUJII Oi-I)PtcPIlI n~() (c ll rellg(nt Ill Pont SP gr L~H) oluUolI ill JJ-ptrtPlI( p[buJo Ily ulullIe iR upd as a lUlJbel Illpd) tall r
lrue(it-c Colloid SrltlioJ for RIlJIII A middottipcImiddotPllt iulutillu of diglycol stellshyInte S Or glycu~ttlill a retllJld g)1I11 ur tlid)(middotul nlmt Hot llYailllbe (luring the war pellod) (bUIll tlellnj(IIImiddotIndt Ulycu Prot ItI (middotu- I i IIllHlt ill lIl0lj)homiddot lille (lecbniC(ll-glu(p EusnHllll I TIll slJ(k ur digl)( [ptrlltp ~ ued ill these expfliruellts on till bUSh of tim (htPlmiulltiom nt iJ C IYIIS illO(i 1-ereClt solub( in lll()rptvlilH) rlJe diglyt1 f(Ulute 8 i blOght U(II lllutiOIl by heating tll( oluuolt is made up 10 olmn I t a tandarll tllllf)(rtltUle (25middot
J Z30 King ltrcet Brooklyn N Y
6 TECHNICAL BULLETIN 920 r S DEP1 O~ AGIUCULTUHE
in the Writl Inborntory) al1l1 fiUerp1 A [j-I~re(gtl1t solution of this by volume is then made it thu k(tone Htptate or l(hPI or tht llIixtlll or tlH~p I~lll as tlw lullber foinnt
REAGENTS HHt RESINS ANALY3IS
Resins SUITIIN- Illixlule I)f a parIs ot lll(IJII~lIllII(JIll Hlld j pnrl~ (If fthSi IllI glnmiddoto] IlHlll1I1thII Nhpl (l(rtiIlHft(l 1CPIlPi i 0 as (middot110lt01middot1 I hr 01111111 botl t((hni(ul-glu(p CnlilOlI amp VHIhi((I h(lIli(d~ COImiddotpl is a gooe1 r(sin~ soiYPllt ~Ihis lllixtlll(I i~ 11(111( (0 ilS 1((loll~Il(ltlJlIPmiddotllll(Jllmiddotl amiddotmiddotj ill thl ((xt (011shys(allts I)f thf~( a 1111 011](1 rl~ill oYlll(s tn )inlI ill lalJl1
R(IIrmiddotpimiddot((middotJitlltill1 iWiIiOl- [i-(J(middotl((middotClImiddot 1I~O (e p (agln Oil Ponl f1 gl 114 J solul iOIl in HO by 0111111( is UStl m I Ill llills pll(ipita nt
Po(- i ( (ol()icl ~lJ11I1 iOIl Ol t(8Iyen-A O-IlPI(lnt olnl ion of (igl~((1 Rtrl ra i ( H or gly(o~t tlill I lIIath ill I (p( ollyln((1 OIl(middot(plJool( j or nlly ot Itpl rlsills solnnl 1I(tL TIJl diglYlol Hipn Ill ((i ~ is (lis~nlaquo hl 1 Itll tillg Illl lolLttioll i 11111111 liP 10 ulnnl( nla Ht1li1l1H11i tl1Il1ltIIItlllP Hilt 1IIllI((1 If thl -oll1liol1 liOllltl )(lOIllI loud) II((IIIP of II drop in ((IIII)(IH(III( 11( plPtipinll may hI hlollgltt IIHI ito ltulutioll hy It(lItill~
SIECIL EQrllIE[ Fon HlIlImn 1) HESS AALY5IS
11I0T())t1~TIG ISsTH L)IEITS
8((1111 tylllS ofi IlstllIIllllltS i Ill 1lid i Ilg tltl C01lIllflii e ] (((Ioni( plW((lJl tI OJOill(hI (oJ II1Illll dolllJltmiddot II lOll el(h1011111 t OJ SPII( IOplJOtollwtpJ Klett-Sull1llllrSOll o1olillltlI and EnIYIl pllOt(l(h-tJie cololimettt han b(PIl II~~(I TIll pilotoflttolOIlIltll apptUPlltly is llot suited for thl pUlposr iJltHlIP thl (hllJlIh~Jjstj of n( l-ollsplllliOlI IlHHStl1lll waS SLl(h that thplp WlIS velY ltLpitllhullge ill the rendingS oil standing of the liOlllt iOll a1tlI rubbl1 nnd Il-ill~ plltipital iOll fltP onitL of prefmiddot el(llce fl(lIll tilt ltalldpoillt of gllntls pllri-iol1 of llading~ is us follow
(1) CoWlIlan dOllhlt 1ll001O(ltlIII1lH I01 IWl1 Iuphllt 0111(1 PI mo(hl lOH 0 COPIlHlIl I1I1iY(lsnl SP(ctI1I11holl1nHt(1 Ilwdll 11-WaYlmiddot1I1g-1 It Rlllinl II t j() mLL is IlCIUlIllPlldl(i
(2l EnblI pholo(lptlli( (olulilll(Il1 wi It (Ining- 1II11 110(IIIUIlHl tie filt lr rOIllshyhillatioll jtl lIllL 12middot112UGc51- villstllt (ap i~ ~(t1 10 ((Jlr nl)lOIptioll IIt tllllP Wlllll 1(IIilll~ HI hlill 1lI1lt1t A nitmiddot fill holding 11 Itlllll nmgllifing IIHli til flllilitatt lIlaldll~ IIPPluxilllllll 11llIII11111letl1 I(adings tn 01 lila) hc IIJ1l1l1fll(lllld 10(lllIy
(H) KlpttmiddotHlIIllnllISOIi (OI(lIilll(tP-So ~Ililllhll Iiltpl (lInrllinnlion of IIPillllXimiddot nwlcls 50 IlIJL IIln( (Ilgth I atillhl( at 1Il(middot~(middotIlt Till ill(ItIIlWllt IWIfOIIlIS Hn tisrt((oil~ wit It th( IlIa iI II 1111 filt hpi ((11 iji 111111 njij IIIl for IlIlIlI(I II nIl1~si on 2-S(tllolll (Jl oltlll glltllh 11111 (prilll wit hlt l(lJlo((1 a 11(1 f(IJ~ currentmiddot plon ~1(jlh (101l IIII plnn[ with 111 t (1 ahlllp W(J IllJL 1l( lig Hl llIi 1illlit it USP(IlII(S$
ltOl the JlJ(~(Il( tlt( Ewlrn pllOtolIl(1 de (oIOlinwhl i 11(Olllllll1H1(d as (hI IlOt eOt1PlliPllt alld ndaptabltmiddot il1trlIl1lnt rOl rout illl lnbolttmiddot t OIY alltl ly~(-
OTIIEH I~QUIII~YI
A lhplllIoI11 i(ally (oll(lollltl tlil huth wilh a l(llIun1l1l (1(11 hllsk(t pllllimiddot liOlWl [0 hoW il)Il YOllllllPI( lIa~k~ ltig ] L llihglmiddota(]( tylil(il oil ~ K O i1((1
A tlt(IHW(1l tielHr (mil 1lIl1td 111 Ipl 1Jr t It IIIIIjdlt wir It lHolol iImiddotI(1 Illld IClllollhl ~(lllI IlIl~kl[ 1111 lt it jllll(( t h()1( i II Ill ltlOmiddotml Yonnrp[ riellllisl)I 11( in stnlltIItlllllg I Ill I lPlI (II 11 of IPII)(l1tlt Hila IIn)UIII of (xIII(Itl saJlpp~ Illkpl1 (01 Ilnlll~~i~
bull
bull
bull
7 RAPID PHOTOME1RIC DElERlHNATION OF RtBBER AND RESINS
bull
bull F1(rJm 1 ~ UIIIltan 11l~IIlInIPIII lo UIIlallt-lllllplalul( ~(II(Inl-[lllrpose hath 11fil1l liS au oil hath Xlltl ~IHinl 1(IIIOIullll win 1Jt[PI 101 holding ~[j-lJll Yo1U1l1plllt flask dUIlng- (xu iOIl ur luJhl t IHI IIill IlIi is uot stlludard ltfJuillll1ll1t nIHl 111lIt hi 1Ill((1 b1 (hI Hllal~-t
Ilm1ll E JIItnslIlPil iIIit (111([ (Iltaslll(11 [1111 In(J nlHI K()(lak electric tinwl Ilw Hutpl H~ 1l~Id ill I1PIIIllIillillg )1IIIdillg (illll n((uInl(l~ 111 111lt minute unll luhllpl HIII1 Isllll al( l11(ipIIIIlP(] 111111 till tOIlIlPI 101 tinling hlHtillg nml (11 tli fUli Ilg 11l1iulls
AWill~ 01 It Ball amp I(wpllluill fol Ull initial lWUSI glinllillg of gtllyul(l UsU( Hoss-llal(]pslr IIWllifillIlioll of Ihl lInlllllHI 11Iil I I plIlIilll] with Xo 1
(~middot1Il11l) nl1d XII (iIIlIII1 (lPIItS LYIPX i lUl(l lOOmiddotml oInllHUilt 1IlI~ llloidltl witlt grolllHlmiddotglns RlOPflllS spr-ial mIIIi 11lx ItitUllIti IIllIkll wllh UIlI illlIlp 1111111 1111(1 gillS
10(1 12 CIIl iclllg h~ 1Ii jlll ill Ilillllllitl wHit gtOllIHI UnllIIPti IlId 1 em In dillllllll fOll1~p illlllllldllg lIbhll slutlon [fig A IUHllJ) 11)( jllpiul heakcr I lIJIIlI1fIIIIIlII11 t101Il Ihl W-1l1I lldUiIl low-fllllli 1IllkI wilh s[lout laquo(olning (llas WIllk Xo 11111(1) Till ll (toul I flatlll1lt1 hr (Ill lgl1lu glllliliIIOl[ing Plo(Il1m Ill IillltllIllI 11111 of Ihl gIllgt ruti aIHI IIIP sUIfa(( lit til( lIat insitle hottnlll of IIII )11111 nl( gIlltlIHI toglll)I wilh Itll(I~ ill 01((1 II) s((Ule the most II tisflnlory SulfH1 rill lil Illl I iOll
P~I(X WIIlIIt glI III 111( ll111L ill thilkms 10 II~( a It tIHS(~ III ([hiding luhl)(I Sfllll[llp
A Iolk Imil fill lISI ill diiltlill~ luhI 1111[111 H(Hy(Inl~ 1~T(lX 10middot1111 gllhmlllI (Pili Iifugp t 111H Ill]lillld wll It (011(1 1101111
lind (ork tupp (0 tit I Ill 2 ()
bull Filt1 tilk (fig 2 IJI 101 1)( with Ihl glltllunlld tublS ill thi o[WIati()n of
llOUling lIIIlillpli lx(nll illf jIIlI )lhIIIl1IY(I lIask IYIIHIlt ([illlluin l(slmiddot Ill At hp II11IPI a )Iuss lOI wit h I tIaltllll(l (lIll lIlS lI1ullIfnlul((l ill the Illhllln(()I~- fol this l1SI bill ii In (lilli(ll1t 10 -1(111( II PIIpound((( tit Howlwei tlte anilnblp filtpl ti(klIt1 tlll 1)111)111-1 lind was Intll lIhs(i~llll(l The fritte(l glass disk SII(S 110 rUlli1 lUll Ill llIlI in tliH O)IlIUlhJll hut hollis hlllk the liqllid II nil lPidlH in till ((111( PHill
Cuullipl(1))ipp(ll for tlllII~flJItng klotlls nnd uthI IlIgnnk Illnnis SlIInl pighin) III I (h li (Ill high alHI (III ill ([111111(1
8 TECHNICAL BULLErIN 020 e S DEPT OF AGIUCUUlUlUJ
bull
IHHH middotmiddotmiddot~Ollll of the ~Jl((iHI ~lnsswlI( reshyquilpd 101 [lh)lI and I(sills tllal~sis (lllss rod wilh lInttPIH(] (ml Loll alld tlitulatioll lJlll((I II]) 101 liSP ill bull IIlnlln~ sto1 solutions of IlliJlPI (olII1i lwanshydlltr -AIIlI lYIX ((1I11ishyrllg tulJl wit Ii 011( poillt (0) nIHI flIIpI stie ( J) I fOlllSP ill P[)lIill~ utl (llIdiIli (X( lels witlt shyout di~tlllhill~ the inshysulilhll Ipsidlp
bull
Glns pound1111])(1 ) jlllll in ((iamptl for 1( ill tltlm~rprljlJg- pighpll fllJlplpS HIIl1
bull (lnrin(d IXIIat to -llil ohllnlllI f1aI~
i(p-mollllt gingt hntl will llntit OJ 11I(lal J(IP (n] fOI toling- gIollIH plallt samp(
Halmiddotk for hllldhlg ill-llll middotPIlIlilnp nlHs IIIH ~i-1I11 YOlIll1pllit flll (Jig- 31 Alltolllnti 10(1-1111 ~middotI(lX IlIllPUp of IhI fq)p llsltd fOl Iitis with intpl(middothallg(middot
nh1t H(JlIlHI joint 101 rl1phl lPfIPIIIlg (lj 1lIhhpl fllld 1(ill lll((jpiltlllls
bull
FllilHE Had Iqllind fool IIJI(lill I 11 (111111111laquo llllmiddot alHl (I) limJ VfIlIlllllJi( tlak~
bull TIll itl1jHlIlWI of n Illb tlpl of d(Hdill(~~ III [gtJ(Jtnllllllil lllll~
i dblmiddotwmiddotpt hy Y (J( I _ j J i) t Illt riflllmiddot t tth~ n n Ii 11 111 h111 I t1loOIlldy witl nap lllltlIHI 1111 1l1id bpll tlll- HII lill(ll with (jtt11lill olutioll Hlld ltll If fla k It It [lllijljtnlld 111bhll nl
11ill lIll til ~tlllld all 111th Ill lillI Illmiddotforl 111l In 1(11 it j~ luhmiddotjlIll] 10 1111 0111 ilH (111(11 11[ Jpli~ Ii tllp wall TIll
10 TECHNICAL BULLETIN 920 U S DEPT OF AGRICULlURE
25- and 100-m1 volumetric flasks arc rinsed two or thrce times with tap water and then with cleaning solution al1tl watel as is customtny In all cases the rinsed glassware is dried in an inv(ltell position at 100111 temperattlre 01 upright in a drying oven The flasks used IoJ extracshytion of rubber Iron1 kok-sagh)z (Talllrl(((IM1 kO-8aghyz Rodin) are finally rinsed wHh the solvent to be used and are nllmnd to lt1Inin and dry under a ventilated hood Cuwttes 01 absOlption test tubes nre handled and cleaned aH directed by the manufacturC)s of the llhotoshymetric instruments used
RUBBER (CAOUTCHOUC) CALIBRATION CURVES
GENERAL CONSIDEHATIONS
The lubbeL hyclroc~rbon stau(ild is pllpa 1((1 by extracting the rubber from guayule bssue ac(ordll1g to tilt SPCI1((-Caldw(llmethocl (5) 01 by the Holll1lH-HaasiH modification of this method (p 2) The air-dry extraeted ltlbber is dried furtlllr in It vacuum OYCl1 with 30 inches of yaCH1Il11 at 63 0 C for 4 hOlIlH Till rubhlI sbindanl is preshyserved h1 It clos(cl contaim1 sto1(d in It r(fligellltol BCfole th( samples nrc weighe(l out the unopened cOIlbdn(l with the rubber i~ brought again to room tllllpelutnre
Two stock solutions each in triplicate from separately extractml standard rubber satnples nre prepared-the first sct of (-111(( containshying 01 percent 01 1 mg of luhbC1 ])(1 lniHilit(l and the other 02 pershycent 012 mg of rubber pel miJlilit(l TIl( (I(~il(d w(ight of rubb(L contiiinec1 in It known VOlIl11e of th(~ solycntis withdrawn Irom Il
burette or pipetted and made up to 25 m1 the standard volume used throughout the procedu]e
The rubbcr samples (01 and 02 gn1) for the stock solutions are weiOhecl out to an aCClllal) of o~ mg on nn analyti(~al balance The rubber is best mnnipulated by mNlI1S of t1l( stJai~ht hlunt-edged top of It cork knife With a little prnctie( OIl( (an leltlily sepnrate t)w desired portions by pLeSSIl1C from aboye Further subdivision Is mndt on a stout PVllX at(h glnssnt lla~t 2 mill in thlkne~s By pressun f10111 above and sheuling aetlOl1 Ye1~ small pnrbcllH can be separntetl so that the requit((1 11l110unts (un 1)( w(igh((l Ollt accurately The rubber sample is then divided into sl11a11 piC(es on the special watch glass by meanH 01 II coll Imife
One mil1ilit(gtl of lt1i isobutyl ketone 13 js placed in It special 30-m1 trituration beaker (fig ~B) and the fine1y diyilt1ec1lubber sample (01 or 02 gll1) is udd(d and heated on a hot plate under n ventilated hood to Il tempelature jllst under th( boilin~ point of the olvent A special glass rod il used t () t rit II ate the sumple (fig 2 11)
When the rubl)(r hll d issohed so as to makl a hOll1og(J1lOUS geUike 111I1SS hot methyl isohutyl ketone or an oI the other luhb(L solvents recommended (t aIJI( 1) is add(d and niicd with the rubber soltItion
31 Diisoblltyl ketoul WIlS not aailab1p (Juring ValtimC l1Cthyl isolJutylletonC 1II1ly be substitnClt1 11111 it is not a~ Cf1kiCni In Illis olllntion If the IllttC1 is used It is b(SI to pl Ilw fimlr diillPll Iubhpl palll(s slan( oPIuight in Ih( solvCnt lind 10 (OPl til (onlalll1 to IllinilllizC elIpornt(111 of sohPIII bpfolp wa( Is nppliecl to completp nlutioll
bull
bull
bull
bull
bull
bull
RAPID PHOTOMElRIC DElERMINAlIOX OF RUBBER AND RESINS 11
The mixture is tllll1sterled to It 100-ml yolumetlic flask with sevtlul washings of hot solvent cooled to n s(uHluld telllpelatUle and madtmiddot up to volume with the saIne solwlli SlwtiaJ IHl(uutioll mllst be takell in transferring t)( lubbCl solutioll to till YolulIHtrie flask so thnt llO rubber is lost It is cOllytllielit to illSllt It j-ill(h funnel in the ne(k of th(~ voiumptic flask to pOll tll( lubb(ll solut ion ill OIl( OLWlHtion into the tube of tht IUlll1ll with Ihl aid of tIl( glllss Iod nlld 10 follow illlshyl1eilintely with S(gtllnl ~Ynshings of hot S() I(111 whkh lIl lilst pouled 1nto tIll btll PI 1I(ld dIIleUy OW) till 1unn1 aId IhpII t1I1uugh Ill( funnel
H time hi not all objllt it is uls() flasible 10 p1alt Ihp linely diided particles of Iubblt ill tl( flask toJ1tuining Ihl sohPIlI 11(1 allo it 10 stand until til( 1lIbbpI is dissolYld TIl( llIblJll ioluliol)s alp slolpd in Ihe tightly s(ojlP(1(d OIUllwt lit f1nks in a ((lol dark placl Thel they willltIIlUlIl (OlUilallt ill Idut 101 an indlfinit( JlPIiod
Two ellliblHliol1 (IlP~ flIP IIltl(l(-OIl( 101 o~ gill of tisHlIP (ollin illshyhw 0] to 10 PII((Il of rubb(I ((1lt)middot1 to U mg of IlIbb(Iill tt ~)-1Il1 yo1ullll) and th(middot otlHl for ()~ gil) of tisslIp (ollaining 10 10 ~l() peLshycent of lublJPl (O to 10 Illg of lulllJpI ill a ~)-))Jl YOIlII1IP)
(Hns HlJ 111 TO 1 II~IWEX( (II BIIII1EH
III oldl) to ll(llllP (ITOI (0 II Iltinil1lIl1l a lIitahl( lllillobllllltp is lIs((lo Jl((lpn (P IhI ~lt of stal1da Id solut iOlls 0 f a Ii ng (OJllllllllll ious ill til(gt (III)(r( Ol 10 1 gt(I((lIt of LubbI In (11( PI(sPIII WOlk th( 1111shypIoypd HlhlHIg mic)obm(ltp Il bullJ) whkh lIi(IlJalpl dlli(I~ 10 0001 1111 was Toulld sntisiadOlY F(OIll n lll-pltIllllt -talHlulIlllbwl solushytion in HSlIitnbh solnnl lt[lIiIlIUJl1iiat( aliqll()l~or n) Ol o~ n and ()t 1111 al(lllla~UIpd (Jilt ut n stalldUld ~Olllli(lll tlIlIJl(1atulp (~) C ill wlitllmiddots labolulol) I IlIIHIl-of II lllillOillIl(tlt illio ~l-lld yohulI(lie f1nks ploid(d it h gla -(OPIllIS gllollgh of 11ll lubhpl sol Pili i~ thllI addltl to (tl(lt flask to IlIak(1 l 1111 Ill1I IUI(middotc (0 t hl all)ollllt of lllbOPI solutioll ]ll(yiously nd(lpdbullflll DI ntl 01 JlImiddototlmiddottli lolloid solu tillil Iras h(PIl Hddld lIP (bhpl is JlI((i pi III tpd IIlld SP(middot(t )opl)()tolllshyd(gt( 01 (jIOlilllltp) IPallil) an IllHdp 1I((OIdillg to 11ll JlI()(pduJ( Oil shylitwd Oil pagp 1middot1 Th( 1(ldillg~ 101 palmiddotll (OI1((III)Hlioll alp 1I(Iaglt1 anel plotttd Hgaillsl t( ntilligllIlll of 11))1 hI n ~)-1ll1 (jIIlIlH 0) [gt(lClntagl of nlbblI (nltuln(pt 011 tw bnis of tl2-glll lilsul Slllllp1(gts and aliqilOt olulllt IH(IOI 101 (itl ]1I(J((dlll( out lilll(1 Oil pagl 1middot1 This PI()((lhll( i ((l(alld t win ill (a(1 (11( II slandald llIbbllsolushytion was PI(gtllllpd IIOIlI slpa latll XllH(1 ld 1 a utln)(l lllbblI 1 III pips TlwcOlllpl(tpdtlla alp pol(l (1) (loldilla pap(laslrowl1 ill figulp I
Tbl )llO(p(II I ill lllilking a (Uln rOl I to ~ jiI((lIt of JlIlJh(1 i~ simi1t1I to (hat rOl 1Ill l1IlP ImI1 to 1 JllI(PIII (x((pl ill a f(middot dptnils The quinlu]lli(Htl aliqllols a 1( sput(d Ht (lI 12 a j 0 (78 n alld 10 mg ])(gt1 ~i-1Il1 Yolunl III sNuIing thp 01 Illg pll 2)-Jll1 YUlll))lt til( (gtIO(ltlIII( outlillPcl ill IIIl PIp(tding pnltlgllIph is followpd In the rllngl 1 toj Illg )IN ~)-1I11 OtIIl1I Ilw (lsi 1(lt1 (oJ)(tlllltlliollS of lubbpI alP s(gt(ul(gt(l h IlIPHsuljng alhplOi- with Xnlional BIII(atl of Stnndlld~ tltllsf(I pip(Ws flOIl) tltl OI-PlIl(1l1 lII))ll sol III ion
12 TECHNICAL BULLETIN 920 U S DEP1 OIr AGRICULTUHE
RUBBER IN 25-ML VOLUME(MGl
100 1~__middotOT5___ITO___15__2~O=--_bull 2r5_---= bull 3rO__~-_40 bull99
98 shy(I) CI Z
~ 97 ItJ II
~ 96a f-IIJ
e95 o l
94
93
92 ~__~__~__~____L-__~__-L__~L-__~__-L__~
o 1 2 3 4 5 6 7 8 9 10 RUBBER (PERCENT) bull
FIGURE 4-Cnllbrntioll curve for rubber in 02 gill of gt1n~ule tissue containing 01 to 10 p(rcpnt 0 lllbhlI (nlnllillg~ (Ill 1111 J~pl~ll llhooplf(middotttmiddotlc colorimeter with 720middotmu filter und amiddotml uperture the 01 divisions required in actual pracmiddot tice for photometric IclHlings arc olllittltd)
Similarly hl the range 5 to JO mg pel 25-ml Yolume the desired conshycentrations of rnbber urc measured from the O2-pllmiddotcellt solution The complete data lire plotted on semilogtllmiddotithmic pttpel as shown in figure 5 A
STANDARDlZATJON AGAINSL G1IA111 ETlIIU 11 ETHO()
1he alternate ploee(lule of stt121l1ald izing th~ IneHell~ method ngninst the Spellcc-Cald well method (II) altholl~h flaSI hIe 18 not adVIsable because of the extra work J(quiled ancl the introduction of the expershyimental error of the benzene extraction method
HESINS CALlBllATION CUIlVES
The procedure for constructing cal])lation eUlves for resins ttIlulysis is similar to thtni outlinlltl for lubb(l lxcept that resins exndate of gunyule is lIsed as the resins stundard The resinolls exudate disshysolves very readily in the resins solvents listed in table 1 It may be prepared in two ways for use as a stnndard-the clean exudate as bull gathcrcd from the plants is dried for 6110mB nt 65deg C nt a 30-inch ltcuum or the oXllllate is dissolved ill acetone and filtered In drying
bull
bull
bull
RAPID PHOfOMElRIC DJllImlMINAlION OF RUB BEn AND HESINS 13
RUBBER IN 25-MLVOLUME(MG) 2 3 4 5 6 7 8 9 10
r~
eo en ()
90
f--70z Q ~ 60ltl LIJ a ~ a LIJ 40 E 0
0 50
~ 0 ~ I 30 0 ~
A 20 I I
o 25 50 75 100 125 150 175 200 225 250 RU88ER(PERCENT)
RESINS IN 25-MLVOLLIME (MG) 2 3 4 5 6 7 8 9 10
1--90
80
en () 70
I z Q 60ltl LIJ a
50 0
a ~ LIJ 40 E 0 0 ~ I 30 0
B ~I20 o 25 50 75 100 125 150 175 200 225 250
RESINS (PERCENT)
lJIGunE u-Cnlibrutioll cUve for (il) rubhcr in 02 gill of gllnn11c tisme conshytainingl to 2G perc(lt of 11IUU(Il I1na (1]) rpSillS in 02 gill of glI1~l1ll~ tissue (ontnining l to 20 nelecnt oC l(sin8 (U(ndings Oil 1111 E(lI~1I llhotollectlit colorlmeter with 720-mtL filtcr and O-ntJ aperture the lO divisions llquired In uctnul prllctlce for pitotoulPtlie PllllillgS tlre omitted)
in vncuo arelntivply HllHlll qUllntity of (xutlnte is plllcel] in a lalge dish since the mass rOHmS nt the beginning of the drying process Pracshytically ull of the ne(tone is evnpollltpd olf oyer a steam Ol WItter bath and the residue is dli((l pnlYllized in It mortnr and preserved by
14 lECHNLCAL BULLErrN H20 U S DEPl OF AGRICULTURE
drying as indicated for fresh exudate In all ClSeS the products are stored in airtight containers in a dark coul place
The usualllnge of resins from gunyule tissue is about 2 to S percent on a dry-weight basis For work with this plaut therefore on1~ one curve is needed A typiCallesins ealibrntion CUlTe is shown in figure 5B
PnocEDuuE J~OH RUBBER ANALYSIS
Duplicate lXiLllCtiOllS arc made for each tissue analyzed and duplishycate photometric readings are made for each cxtmctioll the final value therefore reportcdreprescnt- nn avcragc based on the four phoshytometric readings
Thoroughly mixed O2-gm samples of the finely ground tissue are weighcd for analysis on the basis of l11oistUlc-frec tissllc The samples arc weighed to an accuracy of 02 mg Oil an analytical balance The method of deriying factors for making eOllections for moisture in samples has been thtailed on page
The weighed samples arc trallsien(c1 to the 2-m1 volumetlic flasks with the aid of l-inch glass funnels and 20 m1 of methyl isobutyl ketone is added to each flask The contents in the Hasks are heated m a constant-temperature oil bath at 115 0 C for 30 minutes uncleI a yentilated hood rhe flasks are removed and any adhering oil on the outside is wiped off with Kleenex 01 H similal cellulose tissue the C011shytents of the flasks am cooled to a standard tempellltule (25 0 in the writers laboratory) in a constant-tempelutllre ater bath provided with a motor stirrer if available and made up to volume with the solvent After the contents are mixed the flasks are allowed to stand for a few minutes until most of the insoluble residue settlcs to the botshytom The extracts are then carefully poured into JO-m1 heavy-duty centrifuge ulJls so as to include as little as possible of the settled insolushyble residue The centrifuge tubes are stoppered with cork stoppers and the liquid is clalifiecl by centrifuging for 10 minutes at 2000 revoshylutions pCI minute The clarified lIquid is poured into 25-m1 volushyl1Ietric flasks plOicled with ground stoppers It i impoJtant to pour off the clalificd (dlart in lWIt a lUlllie that the ill8ol11ble cNi(hwis not Sti1((Z1tp A 1-in(h funllel is plncCd in the neck of the volumetric flask A filter stick (fig 2 D) is inserted in the centrifuge tube through he liquid so that tlH enlnlged palt of the gtiek seals off the insoluble residue and a small portion of the exmet in the cone point 1Vith the index finger the stem of the filtel stick is thell held against the side of the tube towllnl the analyst who holds the tube with the thulllb rmtl t11illt1 fingCl The txtlHct is thell poured off easily into the yohunetlic flask without distnrbing the insoluble residne The COllshytents of the Hasks are then ))ollght to the standard tel11pelatme in the constant-tempentl111e wnter hath
The reagent blank us(d wit h the spectropllOtoll1lter 01 (olorimeter ig prepared as follogtvs ) 1111 of methyl isobutyl ketone 01 other solvent used is pipetted into It 25-m1 yolumetric fiask and 01 ml of protective colloid solution for rubber is added the mixtule is made IIp to olume with acidified Oil-pelcent ethnnol and mixed again the rcquired vo]shylime of the mixture is poured into a cuy(tte or an absorption test tube
From each plir of tissue extractions to 5-1lll aliquots 01 the clarishyfied extlact at the stnndanl tempCraLule ale pipcUed into 2ii-m1 volushy
bull
bull
bull
bull
bull
bull
RAPID P1IOTOMElRIC DETERMINATION Ol~ RUBBEH AND RESINS 15
metric flasks and 01 m1 of protective colloid solution for rubber is added to each One additional5-mL aliquot from each pair of extracshytions is similarly prepared to serve as a key to the standing times for the final readings as indicated in table 2 These additional aliquots are first made up to volume with the precipitant acidified Do-percent ethanol mixed by carefully inverting the flask three or four times] and allowed to stand for 4-minute periods before the reading is made on the colorimeter Vith these preliminary rendings a~ a basis the standing times for final readings are taken from table 2 For example if the colorimeter reading in rubber analysis at 4 minutes is 655 then the standing time is 15 minutes
The two rell1Lining duplicate aliquots for eath extraction are then made up to volume with acidified D5-percent ethanol mixed by careshyfuIly inverting the flask three or four times nnd allowed to stand for the required number of minutes as established by the preliminary 4-minute trial readings (table 2) before the final colorimeter readings are made on the contents of the flasks
TADLE 2-St(llllliIlU time for variolls (OllccntratioIlS Of rubbcr or rcsins aftcl iJleaipitation bcforc colorimetric readings mc macle
[5middotml aliquots of rubber in methyl isobutyl ketone or of rcsill~ in ncetonylncetonemiddotcellosol e 3middoti both made up to a 25middotml volume with pr~cipitantj readings on lvolyn photoGlectric colorimeter with i20middotml (690to iiOmiddotD11) filter and Umiddotml aperture]
RUDDER I
Range of colorimeter Approxima(e S~nuling i Rnnge of colorimeter Approximn(e Standingtrial readings after 4middot range in conmiddot tJIIIG for trini r(adings nfter 4 range in con tifillnlOalcor minute stunding time tcnt In tiSSU(l Unnl I t I t (rending IIlIDU C stum Illg lOW _ tent III Issue reading
Percent Villlits II Perfe~lt Jfinul 955-999 bullbullbull bullbullbullbull 09-01 00 01-03S bullbull ~ _bullbullbullbull_ Jl-O9 10 743-954 bullbullbull ~ bullbullbullbull __ _ 43-10 30 1420-550 bull ~ ~ 137-94 5 6_3_9-_74_2__bullbull_ bullbull bullbullbullbullbullbullbull_-_---- 6__8-_4_4---___ bull ~ ~ bullbull ____ MQrcthan 13ibullbull_-~_ _ ____ 15_~elow t~ 2
RESINS -----------------------------~--------
957-999bullbullbullbull ~ 139-01 60 11419-amp11bullbullbull _bullbullbullbullbull ~~ 13~5-939 10729-956bullbullbullbullbull_ Ii 25-1 middotJO 30 ~gtl2-40(L bullbullbullbullbullbullbullbullbullbullbullbullbull _ 2025-1320 5 595-728~~~ bullbullbullbull 8 as-G 20 20 IBelow 292 bullbullbullbullbullbullbullbull- More thun542-591 _bull ~ bullbullbull_bullbull_bullbullbull 038-039 15 2025 3
I Precipitated with O5middotplrccnt HSO in 05middotpercent ethanol When the npproxilllull concentrntion of rubber or rcsins in solution is not known trinl colorimeter rend
ings atmiddotJ minutes s(nnding till nrc mndelS n guide to the required finnl standing time indicated in the last column III prncticc UII cxtrn nliquot is prcpnred for precipitation and thIs is discarded after the trial reading is mnde
3 lrccipitnicd with OmiddotpcrccntlhSO ill HO
PnOCEDunE I-On UESIliS ANALYSIS
The procedure fol resins unulysis is the same as that indicitted for lubber analysis eomiddot(I]lt that f he -olyent js acetonylacetone-cellosolve ~)-7 tht precipitant js O5-perctnt H~SOI in H 2 0 and 01 1111 of the protective colloid solution for nsins is added to each 25-m1 flask conshytaining the aljquot of the extract before the precipitant is added
PnOlmmlHlC INSlHu~mNTs UECoIUlENDED AND CALCl]IAlION
OF UESurlS
Photometric readings of percentage of light transmittance (T) ale made on the Coltnum double monochromator spectrophotometer at
16 lECHNICAL BULLElIN 920) U S DEPT OF AGHICULlUHE
750-111 wave length or renclings n1( mnde on a colorimeter pLoic1eri with the monochromatic filter eOIl)Il1l1tioJl for sllecting the npploxishymate wfLYe ]cngth at 750 1Il~ For routine deterlllinations the Evelyn photoelectric colorinwt(r ployided with aTW-lllJ filteL is IC(0l1111HIHtll
The liquid in hich the preeipitnted lubber uld rcins are susshypended is pOll(d very cHrdully down the ill~idl of th( clette o absorption tube to lLYoilllllC fOLll1ntioll of ail bllbblls Aft( LUbbet find resins preeipitation wlwn the EnLynpho(otkcllie (olo1imetll is used the readings are nmde nft(L thl standing tillll- hOWll in table~ It has been foulld (OIlllliellt to 11lPtipilatl tublwr 01 llsiIlS from the aliquo(s at ~-millute illtlLvals This allows stlilieipnt tillle to check the eOlolimet(r and to makc 111( lNHlings Vlwll a ehangp is IlltHk fLom onc rending 10 the l1lxt it is advisablp 10 llle the clIvctte 01 absorption tube nt lpast twkp with slllall p(Iltion- of the llllltiol to be leitd
After the colorimd(L lluding lta e becll Iltndp till IlIl II igllIlllS of lubbel or resins or thc lpL(el1hlges pnslnt in Ihe aliqllot are r(u1 from cal ibmti(Hl (urVlS (fig~ 4 and raquo or from plepn Led tables of eqllivallBts baecl ill each (liSP on (x[lerimPlltnl data The results are expressed as percentages of dry weight (S hours drying nt 100deg 0) of the original tissue The errol lltle to lCflyjng the insoluble residtH in tbe voltlllletLie pxtLHclioll flflsk wlwn the pxtrnetis being mnde up to YOlllmC is V(ly slight sinlte only (U gm of tissue is used FOLroutine allalyscs lhis ery slight eLlor mny be dislpgnltec1
EXPERIMENTAL RESULTS
The experilllCnlal reslllts Oil hi(lthp method- of tU)lPI and l(sins analysis a le based ttl( d icussld blicfly hlrehl
PHEPMINrlON OF SAlULES
No difliclllty was expPtitI1(ed in pltparing slmplls of llllrscly-glOrt guayule plants 1pss thnn ~ YPH1S old 101 rllbbpl alld IPSills analysis In the cnl of Odll filld-gl()n gllayull plants PIIOtS hopel mtty be introdmp(l by the custOlllalY Jlwrhod 01 pICpalillg Ihp sampl(s 101
HlutlYHis as is lwipfly i n( ita ttd ill th is s((tion Smh enOlS do llot nffCct the ])lCcisioll O[ t1H llwt hotls for LllbbtL n nd Il~in~ nnn I sis i nee till) are due solely to tIl( tbsup--ampling (llo(pdule in thi (a~e of oldeL field-grown plall TIll 1lllt1lOcl of salllplill7 fipld-gl()l1 plants JllOLC than ~ Y(HrS old thenfort Ieqlliles iurtlHl jnttigntioll
lgtAHnOILr~G FOR HEllOVAL OF UUVLgtS
Parboiling which (onisls in boiling gllltyule plants in water [OJ
8 to 1~ ~ninll(s ~s col1llllonl) uSNl a~ n llHans of Itlli rCnl()y~l prior to drymg nnd gllnllng It I~ tHI([())P ll(e~Sllr to ltItLeLnunc all possiblt~ eflct oi tlti PLOtPlllll( )ll (Il( final results Exp(liments have sh(nm that (helt i- fl Flight loss ill til tmiddotjght of lOO(S and 4(ll1S In I typi(ul lXpelillltll hlu1llHs of ~- ii) -1-ytII-old gllllll( pllllb were Italnd at randolll Olll ( of talns wa- paLllOil((1 and the le~es (1( haIHI-pi(kpd [lom till o( hpJ Ht Both pis (1( dlipd for 48 hOttlS at (i) C in a llI((lwlli(al (011((( ion Oyell Th( lpsult are SUI11111I11izNI itS follows
bull
bull
bull
bull
bull
bull
RAPID PHOTOMETRIC DETERMI~ATIO~ OF IfCBBER A~D HESI~S 17
Dry ucilht lust ill lariOilillf
Plaut (pcrcrllO 1 1 -I2 ___________________ _
213 _____bull _____ bull __ _______ ___ ____________ 12 2(
pound(111_ ______________ 1 R
4_______________ _______________ __ _____
A __ bull __ -_
The efred of parboiling on till final lllalp i SUllllllatmiddoti7(middotd ill figmc G Rubb(1 lecoYelY w(t about 1 percent higher for parigtoillltl plants and lEsills re(ovelY somewhat o-er 1 i)(lr(lllt 10Wlr The (Ii tference in lublH-l r((o-elY cannot be ae(01111tltlt1 fot by loss in dry weight _ due is to be found in a study of thE grinding lwhadol of a parboiled and an unpnrboilEcl shrub The grinding of the patboiled shlub in the hnml111 mill is much fadlitated and ns a rule for tissue with a rubber contCnt below 10 peteent llO aggregates of rubber deelop in the 1Il11ehinr during the (Jpelatioll Yitll the unpnrboilNl shrub some dillictdty may 1)( (lxppliellrl(l Sill(( sOllle of till sti(ky ltxlldutl Oil the plant may scI( u nlldei for the fmllHltioll of lublH1 ngglPgates Til is apparently explnins the npparlllt los in ruhbpl frol1l the llnpariJoiled hrllb as eompnlelt1 with thl palboilld (fig (i) TI1(loss in r(sins
II
RUBBER
10 f-
Ishyz LIJ 0 0 LIJ 0
9 --RUBBER -shy-------shy
-- RES INS -shy---shy-----_
IJ) 8 I--Z IJ)
LIJ 0
0 7 f- RES I NS -0 -shy0 LIJ III III J 6 f shy0
LEAVES REMOVED BY PAFltBOILING
5 f shy -shy - BY HAND PICKING
4 I I I 35 30 25 20
SCREENS (SIZE OF OPENINGS IN MM)
FIGlRE Ii EtIe(t IIf pnlticlp sizE Oil lEcorPQ- of rubber lind (iiil1s when lEgttiye wEre remond hr Pl1liloiling lind h~ hand pi(king ((Dlltrol) plllllt1lt groUlld in t hammer mill
6114038-46-3
18 TECHNICAL BULLETIN 920 U S DEPT OF AGRICULTURE
recowry from pUboil(d shrub may be due to the loss of the resinous exnc1ate during parboiling This exudate forms ns It SClim on top of tlw )iquol in the tank
On the basis of t1wse results the recommendation is made not to yaly the nwthoC of leaf lemoYal in any 011( lNi(lu(h project Then fltirly compalabh IcmLts should he obUiined
70 ~------------------------------------------~ LEAVES REMOVED
BY PAR80lLING ____ BY HAND PICKING
60
-I-Z 1amp1 0 50 a 1amp1 a
en 1amp1 gt1amp1
40en gt-CD Q 1amp1 Z
I shy 1amp1 30 a l shyx C)
1amp1 ~ J 20 I shy 0 I shy
10
O+--L__L-~__L-~~--~~~~~ o 10 20 40 60 80 100
NATIONAL BUREAU OF STANDARDS SIEVES (MESH)
FlGntE T-lJiMlil)utiun of l1Ultkh si~(s of gnll~II( tiSSU( JrIOllll(l in a Ball amp 1ew(1 mill to pass six dllIerNlt S(I(euroII 1(IlYes Iemoved from plants by palmiddot boiling 11(1 hand picking ((olltloll dpfo1iatld plants dried to 1I lUoistufl l0I1t~nt (If 01 to o) 1)(ICl1It ground tiSSlli IbalH1 1() minutes ill II ~i$hel
bull
bull
bull Kahn shuk(f
RAPID PROTOMETRIC DETER~UXATIOX OF RrBBER AXD RESIX-i 19
GHl~DIgtiG
bull Th~ entire pant 01 plant l)iHt a~(gt fl r(ll it pllllIIirU1ry lSillg fur J hours ntGi~ C prIOr tD t 1( plChmll1atmiddot rLlmhll III a II lItmiddot or n Ball amp Jewell mill ~n llltllysis of paldch lzP- nftl~l (oar-( IIindill shows that tlwy ar( about tIlt llllH fOl parbojlP(t awl IJllllluhoileu hrubs I fir 7)
The coalilly gloUllll ample i-- thPll Ildlll forI toUtmiddot at ni C afnr which it ha lllilobtllL(gt output of ~ llllut lII hmiddot- dptPlIIlilwltl by drying submlllpil- at 1110 fot hOtll- TIll 1 IIIIll i lltllt lmiddot0l111d hi a IluninHl mill TIll mo(lel uP(t in thi IIIk i 1I Hu IIIOilll mill as IllUllifill bv Hoss nnt Hartlet ( 1 -[1lt111- with n1ll1l1 pldushyrations ittI lilnbhell b rill HanlIolll V0ll11nHiol1 ElIillllmiddotrill (0 The size lutllihl11 iUlJnole So I ( 111m t ~ II t HUIII Xl) ~ I L~ 111m nnd So 4 lillllU1 11 ttllilhmiddotj 0 r tllP Imiddotlult~ p(lln-It willI t11(e Sll((IIiZtS with )arl)Oiltll awl uil)Jtllboiltd hrlll b lOwl1 in fif1l1fmiddot-- This hows t tnt 1middottttIl ~(I 1 llllll (Up jlllilnl IHlt that
r------~-------r--- ~ --r IHAMMER-MILL SCREEN
O~ NO1
NO2 ---shy U NO 3 ---II
I
bull lL
z
r ------ l 30 ~ gt III
i I Imiddot
i ~ I
I 1 I I
~ 20 I - 1 iii 1[ r 10 ~ ~ ~ I _ ~ I r A bullbull
o bull L-~__~__~~__- ~~ 20 40 60 80 100 40 60 80 100 200
NATIONAL BUREAU OF STANDARDS SIEVES (MESH 1
Yutln I i-tlillltiuli Hf pur id lZt f ~naY1l1 t middotnt r1 lI1 i ~ a hatlltlllI 1IIi11 to 1111 Lx IHtllllH middotIn Lt-anmiddot tIlllunl loy la1 litkh~ omrl t 1) tHul parbuih~ -t B ~ thmiddotfuliufptl ]~lahr thpt tu tt fit t 1 It+gtr-tt1 Jnui~tHn eunttlIt _~rnlitl tl~UP ltakmiddot~~ 10 UddU it~ 1 rtmiddot4~pt~middotK1~r ttakt-middot
bull So 1 gingt- 11 tt-liuin-Iy ltr~pl [lPlItl1tat of iilll 11animiddotImiddot- Eqltrimiddot tIlllll hnnmiddot llOWIl dutr fll llltldllllUU xtlutioH 11pound lnhbll lIl lP-ill frolll IolUlIl ~tlaYlllt tl-IlP by dlt IJwtmiddotlUlmiddot lItlilwd oil Ill 14 - 01
i-mllt 11111- -lwltld hi INd I li~ Ii I TIll lllhtIlttj of Itiu~ So 1 (lltll j thnt 11middotmiddot01middot lttwmiddot to amplil tltt Iollllli tilt art lpdnn ib
IntIIll ll~ i po--ihJI with tI lLllit Ilfltl[lll1t It honld l Plllplw izmiddotl rImt ilt tht h of -allllhmiddot with l lllblPl
~ontlnt of ill PPltllt til lIilll it i tlllt pll--ihl 10 11-middot t(1i Xli L
20 TECHNICAL BULLETIN 920 U S DEPT OF AGRICULlURE
Even with screcn No 2 difficult due to rnbbel tlcrltreCtlltiollS may be ob tl
encountered In thes~ caHeH it iH lWit to parboil the shlub fOL leaf lemonll and finally to dry to about 1 to ~ P(l((llt of tnoiibl1(l pound01 b(~t results jn ~rindillp in tlH hanmHl mill
It iH aclvlsable to provic1l thc hammer mill with a ground wire Hillel the presence of static electric (harges 011 tll(middot partkhH will ealls( Home of these to atlhelc to the inside of tllP (olltailWr OJ lila eallsc OI1l( of till pULticl( to form ngg1(llatls EIIolin lalllpling fl01l1 fhis SOI1I(I mlly be (onsi(h1llbl(middot
A1I10l1g the Holnllts with high boiling point that lIlay Ill IlHld in rubber anal)Hs I1IP Illllhyl n-alllyl ketolle methyl ioblltvl kptOIH diisobutyl (tOIH blltyl tHptate llethyl amyl 1Ittail (middotthyl(middotlllmiddot gly(ol diethvl (middotther and n-bntyl (middotthel (labl( 1) TIHse al( also I(sin 01shy
middotent but th( 1(~illS n1( held ill olution by the rll1)bpl pl(l(ipitant tthanol wll(1 lllbb(r is 1)J(lipitatNI (S(ll tabl(s alldmiddotl) On tIle basishyof the lxpHilllPlltH tll( btsf nil-round lolPlli -rol lS in 111( PIlHPllt method is lt1iisobutyl kPtonc wld(h was not IIltlllllfaltllllmiddotd ltIlling Vodd Yflr n A suitable Sl1lgtstit ute iH llHthyl jolllltyL htolt whi(h is l(porhd as llolltoxit UJ)
Clllos()IY(~ (ethykn( glYlol monopthyl (tIH1) blltyl earlgtitol (di(thyl(ll( gly(ol llIollobutyl (ti1(r)~ and acttonylacetOll( may be used as resins sohrCllts (table ] )
In the earlipr work with (sills analysis cpllosoly( alolle was selcmiddotet(d as a suitable solycnt Aitholllh (ell()~oh( alone is pxc(lllnt its rplllshytiwly gwatlL iscosity 1(I(b to bubbl( formation nft(I (SillS pr((ipi tatioll Thi- increased thp (xperimentnl (LTOI OIl of tltp othll I(sins solpnts tI((tollyla((tolH has the proppry of glpatly lNlulingshydH(OSity 11(11 altld(( 10 othr liquids This sohpnt tlHIeforl wa addp( to ((Uosoh( in slIflici(lJlt tlllIonnl to OPI(0111e the dinieulty On the basis (li~ex)le1inwllts ~ purts oi~ a(donyla((tOlll to I puts of (elloshysoh-f (bolll by olume) as Splldcmiddot(l Thp 01 hel Hoh(nl listed hutyl clLlbitol at l(llst the t((hnieal-g1lld( ploduct uSNl is appal(ntly not as good as eithe of t1w ot1(r two () a (ombinatioll of tlWSt
The SOlVllIts JOI liSt in tumlyzing artifkial lubbel$ hy tlw pr(senf method appllLently (lcllIHl on th(middot kind of llI))(I lIp-ityl (Jxidt is suitable Ol BUlla fi and hutyllthlI for butyllllbbl Tlwse reagents IlLe technical g1lld( Calboll amp CtllUil1t Ch(lllilai (OIP This Hllbjp(( hilS not bepn (XtpllHl(ly illwtigated by till WIit(I
PIIECIIIIJ-
All tlst fOl Ih( adlqlJalY or till IHllipitullb ll(Ollllllentillllll11Sl bl baset] on the plctisioll of tllP final I(snlts oiJtairwd with the methods The )redpittlllts s(1e((( n HpJ (xtcllsi( (xp(IimPlltatioll all HatiH~ factor (Hee fig Hi 111lt1 tabItmiddot (jH) Ext(IIin tllts llllTild Ollt hanmiddot shown that H Hatil-gtflltlOIy [gtIpeipitallt 101 1lIbblI is (li-p(IT(middotnt HzHO (c p reagent nil POll sp gl U-lmiddotJ) ill li-P(l(Put (tinmol by vohmlP liol (tllayul( Ipl-gtinl 1l)-P~ITImiddotllt H)~o ill Hl) by ollln( ii lL satishyfaeto7-y l)lp(ipitunt A solution of 1 palt of H~~o to 1 part of H~() (1-1) iI2So1 nnd abo yarious int(lIlIPdiat( proportions of tlllse suhshystanCPs giyp fait 1(511It8 but with till inlIptl(l ill [h(gt ratio of H~S01
~
bull
bull
bull
bull
bull
RAPID PHOTQlIEfRIC DETEMIlXATIOX OF HtBJER AXD RESIXS 21
to H 20 the )olutioll becollles somewhat vbcou5 and precautioll Il1Ult be taken to ttvoid bubble formation When it i5 poured into tilt Cllvettes
It should be lloted that both of these precipitants have an ftellleshymmiddottion It was found that when XHjOH was used in the rubber preshycipitant in pInt of H~~O~ the readings were -table l)Ut were not reshyproJutihk The lIl of XuOH in pInel of H 2SO j ran nHittble result as a llth H(HY(Pl WIWll til( li-P(l put lthatgtl in lublltl llnalysis or H~O illlP-ius anal)j wn-i uddint(1 thl eharalteliti(s of till liquid with pleeipitated ruhber or resiu in HI~P(ll-ioll n ren1 on the lpNmiddottroshyphotometel m tololinlPtprfollop(1 it lPgnlal lIlll II~ lxplaiHd on pHgP-I (Sl( figs 11 aIlIIl) Tid made it lloible to outain lEPJOshydlHibll tpnlt nntI (onplt1J1(Jttly till JpqnitPIl tlPgJPP of PJPcljoll
IIWIE(TI 1lt COl~101J)
Jtl thp ItJiPl middotxlwlillltnb hefoJ thtmiddot -1l]YIlIt allll pnmiddotdpitallb had lIptll ptoppJly adjutp(l it l fOllll tIuH till llP or a Ploltiw colloid -wll ltIi1)cJ [ttlJmiddotntl- imlIopl tll lmiddotpro]lIibility of the lPlllt JmUkllly ()Ilt 111 U lput lUlU illlihumiddot tOJllPOlUtl tpHd liglyeol teltlut( - llpanlItly IllmiddotlfP(] to lit til I1m t IHflll lImnnmiddott nftlr tlH filial prOIptlllll WtlP dlvPllill1 tlll 11lIlpfit (If thtmiddot [llltlltin lollohl wa Hot 0 natlv I1l(lhmiddotd III rlumiddot Ia- of tmiddot ill tllmiddottJmillaritlu it b [1 hmiddotjlmiddot til IIpoundgt Ir llH1 It liltr ill-llImiddottiT Ina lll ptlPII by it U( in ruhhfl mmly j 11If dtmiddottail fOJ tltt lllllmtlllll If thl plot pet in nlloid ~llntill tltlmiddotlImiddotmiddotlttlatiflll lIOlllllllhtiPI1 are iPllllll page
liTFHFEHliG COIOf
(hi II tht lllail 11111111111 that had til ill -111111 II urklll) om tlH method fot lublJtt tlIlO1 rpir- nlalv~i in plaut llllpll- wa ttl (lilll~ inare tIte (gt1[01 till to tIll ptP-PlHt f xi [aIWIIII- 111 TIlt amount of (olor varip from lUllIt tn -amp ]pplwHlI nlt rhmiddot lt IIf thE Hl(ltllial tllP part of till plllIt -lI11lhmiddot(l tilt hi-tlllY f tlll plaut mtteshyrial ~ub-lltInent to Itlllmiddotnmiddot-rill lliI 1011middotly OrllPI Inlw
In ruhlwr lrtl-i I Iii 1101 au Itmiddot 1Iplll11l by 111[ I--r ratmiddottilt thE -lllll]t with uptoIw or 1middotmiddotlIll-ol - wIdell [llllol- rlll loillriu nutttel autI thtmiddot lpill- Thi- howmiddotvt n(tnll- til lXtla -11gt1 ilt prlJ~edun) In lP-ill ltluay-i nllHufldy tlW[t j 11 1 1IO(PIlln fill the 11shylImya of hlulophyll Hwl rIlI-r middotIOII IHlttlmiddotJ dlH lUtl~ In plltIH withoUt alo aiftIriL till nmiddot ulttrll
111 pllIbIll1l Wi tilmiddotr hId h It-ImiddottHI tht Pltlpll 1 hlitlt lilt tlw tulllWlli tollImiddot uIwltllIIntut -lltUIhorlllllltll 1111 tIll tlettlllliIttwr IIf t 111 lWlrl-Uamiddot of bdt tl11blLlittUhmiddot r [1 tItmiddot preshyj
lipitatifll 1lJ llllllWI atbull 1iI- in III -1nrmiddottIi fHlttalldh nlrillU~ amount rf middotlorilig lIUlttll Iii lhll of ih lltmiddottllllhottohttt~l l~ol()r infrtl Hm II upd 1 rwmiddot tld~middottilmiddottll PlllItlhi~ f it j proYitiltl with tIll lilP--UlY tU(jlIdlllIlml tIltmiddotmiddot lllklllUIlI
EIECTIol OF 1 [EGTH~
-Ptfmiddott ral tracilull ru~lI gtIll fr 1 nllb t ~xtltd 1 lIlt-th vI iobmy1 ketommiddot lWtl rill [ Ixt lttltt ll UttollylaIiIitt1l11I1t~ ~-I itoiu YtHil)u~ typp of ~IHaylllt f i lItmiddot art hraquoil ill fio1ll1 ~l Th~ lp-nlt fill I11oohl uio[1t ttl willlr til tltN- fur rht IUiXtIUt iwliutll
100
22 TECHNICAL BULLErIN 920 U S DEP1
90 bull eo
I shyz 70LLI 0 a LLI a 60
LLI 0 50 z
a ENTIRE 2-MONTH-OLD PLANTS~ 40 b ROOTS AND BRANCHES OF ~ 3-TO 4-YEAR-OLD PLANTSen z WITH LEAVES REMOVED ex 30 a C CURRENT-SEASON GROWTH OF l- )-TO 4-YEAR-OLD PLANTS
20 WITH LEAVES REMOVED
d LEAVES FROM 3-TO 4-VEAR-OLD PLANTS
10 A
0
a Cd 100
b bull
10
80
I-Z 70LLI 0 a LLI 60a
LLI 0 50 z ex I shy 40 ~ en z ltI 30 a I shy
20
10 B
o~__~__~__~~--~--~--~--~----~--~--~ bull350 400 450 500 550 600 650 700 750 BOO 850
WAVE LENGTH lM~)
FJGcm O-Sll((middotlllll tramaniW1IHl (mrpS f(JI (xlmll 11011 n J1ll of jlta)nle tissur ill n 2--m1 Y011111P of (A) Illrthyl ji1I1J1ltsl krtonp 1111(1 (ll) nt(middottQnyla(umiddot tClIc-C(l1osuln a-i
bull
bull
bull
RAPID PHOTOlIElRIC DETEH-UXATroX OF ntBHEIl AXD HEstxs 23
ThE dula Pl(S(l1t(lltl indi(ntp Ihut 101 Illp ulimls llHthyl liohutyl htOlIl (lxtrHts (lI(I r(dolls of Il1Hxi11111III nigtol]gttioll wiH1I all (is-lIb 11 cOllsic1(]((l n1( blhn(11 wn ( ItIl( Its lIO to () I1It~ nlid Ii to Iii mJL
WhllNIS tlw I(gions of 1middottnL(s( light 1lnlllittamp al(l lgtPlW(PIl wan Ipllgtltsnr) to Ii nllt jW) 1I1JL nlld alio Silllill1l 111l1b (n SI(lIlId 101 nc(ton ]altmiddot(fmiddotollp-(llloolp ~ pxt Ill of 11a 1111 t illl TIl( (1101 du( to lolo ill tlw litlltitl a 1Il1 lullll(I tH lPill- hanmiddot bpllI PI(_ ipitated ma he 1((I1((d to fltI ynbhing poillt II ph( illg OJ illshylmiddotJall(( WIWp balld nhm ()) IIIJ1bullbull[1I111 lxjlPIitllll1b Illln -h()1 that Ih( lIIot uilahl( WHYI lHlIJ fOI 1-1 ill 1l11J1l(I HIH11Pill- illllllrsi i-in till IlPighl)()lllll()(l of ~llIl1lt bull
bull UIlIilHlIy of n typhn] lXPllillllllt to )10 l1iP(tiP ((JIlllo( of (ItOIS dul to lOIOl in 1llblnI Hnd Iill xtnumiddott 11(11 IIIIolp t jUl i p1llelll((l ill tub]lL Till llhlllt- 1tpIO]II Hnd ((llll~()h whit-h UI(I ](]Hllilltl n 1I01lllIhb1 01(111 lxt 11111 IIll 1llll)1 nmtp[in I and )(middotills Tid IIlnkl it poiblp nftlI tlIp uplll1tillll or tlll o1PIl( (0 [niH lip 1Iidl1p~ of lI111 11111(( ill lit ll11l1)[1 (llnlIb nlld Ihll
Sl(ll n ol1lliOI with tllP olnl IJllt illiollt HIl Iltlllll llllI (Ill ltllthpl prpipitnnt j Ihll1 nddld OUI ha a lIilPt lP( of till lIiciPlw of WH( lllIgth 7) lUI- ill llilllillatiu (nnl till tll Ixtll1I101l ()lll~
Tuu tmiddot-Elilll IJl flrldillY 11-1111 lrlllI IjfJI til islII 1 1(1 ([rllt IIIIIJIlIr JiIlIt~ if 1Il( Ihll 111111 k til I III Ilrln I 1Intd tf 11111 JiSf fill I I II I tIII Ilf Iilltl 1f1JlIIillII1f I Till 1[ 1 IId 1 (I (middotIt 11111 (I1I1iI1 1lf1IWtlfJlIIllfflr p middottrllhIJ11 II J III 7IImiddotIa 111 111 lilt jJIp 111 wilTII
t~t tnVIli~ ~nn r kn t~ i tmiddot ~~l Jr 1middotmt ltlTt
HmiddotOtt ~I~ lin t I ~ 1 t~~l ~qrmiddotthtmiddotrtwb
Hult-middottltlru t T Hw ullut rHtt~ r II I ~ PH~lllt
A~tmiddottHHjmiddott~rjd rl ~gtllh 1 tn~th~ ~ ~ middotI lt~ b w bull hmiddotth~ 1i~lIhun 1 Ii tnl Illd1 -11lt1(11i lullI lUI tJl ll~ t1~11n( I Ihan1li flfttIJir Ult I Uuhtltt ahuul l(hmiddottHmiddot~t trv r fti HIt lftbyl tlonhUt)1 k_hIl( 2 m~ fmiddotf tuhlHmiddotr In mlth~ llmiddotlf- 1 t r
t r_~ t j
Arhlitlltd ~llIIDHl NcWitn1 ( Ar-(lt()nc~middotttrrtrt ritJJI~ -Iu nllJtl4-middotr
ACtmiddottflnp fmiddotxtrn( ~ T-P511ftf tn mtmiddotth~ 1 ~difmiddotut~ kdn 2 nltt ulruhhtr in Un-tIl lltbu )J~IYt
rUth(Hl~hltlft HhubU
Illlh(I(t tttUtUt hUbtl til J ~jlitl(J Hilllll trtIIImiddotjtl1ll
(UShl I ~tlO wHllolH rulh r (middot1111$0]( J~rru t t )lthyl 15bullbull1middot1101 klll1l
Ili( UHUicbcul ~((i1rUtl ~ulu1iin 1middot lIUIll Ilti lrllltlllt I Ruhhr llt1thuI r1 -1 Irld
ltlt1111Sh 2 nuz f)rruhl~rm nlith~l tu- h f nt nil~middothgt(H] tlrlftmiddot 9lUtirtl middot1 1
rlcltfl( H(l dnllltml it
(IISllhH~rI( Iultruhtr CII05 1v ltTlft I 2 UI~r ublwr In llldh I hlt~1 11) lgtjdvr(llsl~9rlltmiddot middotlmin ~ I~ gt AIHItilltl no IrttipHallr iI
~ Bbnk 10ol m(thyl i~tmiddotut~i kdHn H 1 m1 j~~ l1rH-t lt~tlfltmiddotn sf n it ll HltlMjftr~nol O2~mlJ ~U~1o-ulp ti~tW -xtra~middotl(lt1 ltt 411 ml bull ie f Ct- kft rt t~ tirattJ middott ill r u l1kn ttJt
in metltl isobutyl kNqnf nn~i mljp ur tmiddotmiddot ~oml ~urr tttl i t w ltJj1JH kt 4t 3 nlank 1 mL((l1t~rthmiddot(middot mI mttr~ ~but a kmiddot tmiddotc d 11 ~ gtli~b~ hifIAft- fl~ lL lnti 149
ml8(dlfilll BO bull 02 gm guayule U$Stl(middot xUlClt-l tf(h tft wI n nmiddotmiddotmiddotlgt 1 lznt on tmiddot ~Jt r~1 ~~u~~ H~ iI~ thT
24 l$CHNlQAL BULLETlN l20l S DJltJPT OF AGHl(CLlOHJltJ
In table a is pl(sentc(l such c1il((t edlt1tIHC showing that thc (0101 Ixtrnetccl from guaYIIle tisslIe wit h II(P(OIl( n nd (pl1oso[yc is cll(div(ly sCIe(nec1 out by the s(lp(tion or wnw length )0 miL Oil t1w SI)((IOshyphotonwtpl This tnb]p all-HI ihos thai thl Juhlwl altl(l((1 (nn IJl quall shytitntivcly 1(I(()(Ipltl in tIlt PI(ilIH( or Ih (o]OIplnwPIials and Illsins and tlmt Iuhb(l WtlS nppnlllltly 1I0t (xtltI(((1 110111 11l glll1I1l lisslIt b~ tlHSP SOhlllts Thls( ((suIts ginmiddot (OliIHillg (idJt(( that t Iw IISI of waYl llngth i)ll 1Il) OIl till SppdTophot OIllltPI ii t hl 1101(1 p(oshy(ellule in photolllliTie IlIlalysis of luhhlI OJ l(sin-
SELEGTIO- OF )IOiOCUHO)IAIIC ItIIm ((1111110
On th( basis of th( IPHIlb shoWIl in tabl(l 1 al hlllpls (1( IIln(lp to SPCtl lC the PIO]Wl 11101lO(lIOl1ln til Ii ltlJ ((lIllIJi nIl ions 10 llIiOlS (oIOlimet(Is 111(gt 7W-Ill~ filtpl flllnhwd 101 til( I1~lI1l photoshyplpct1i( (o]oriJl1ltll fol which Ill( (hlll(IlIiitit~ oj t hl Ilda he light ilUIlBlIIhiSioll (t) elll nn -hO11 ill fig1lle 10 iws satlsfa(lolY IPshysultl 111( iiO-mL HitlI olllhintioll 101 whkh ttp (middotIatinmiddot light tlnnsmission (ullmiddotis a 1-0 showlI ill figllll (I is -nthdnlto1 hut this is not stnlHlnld NtllipmPlli
Up to fhl PlPHllt lIS(middotflll pound11((1 (ulllbinntions jn lltl iOO-I11L Iunge hayc nol bllll SlClIlld 101 lhp Klpt 1-1I1l1I11PISOIl (olOlinwtll bu fnltlwl nttCl1lpti 1( )(illg IlIHd
TJIpound OF ST~lmW AFTEH HIIJ1EII Oil HHSIS rlll~CIIITTI(J
~ considl1ltiol1 of ttp lillll of Inlllling af((1 plpeipital ion of 111gt)(1
01 l(sinSTlOIll ollltionis impoltant J(jl~ thC1HI(Plltngp of light IInIlSshy
11 rshy10 f shy
09 f shy ~750 Mil- DOMINANTI
~ 08 cshy I WAVE LENGTH z
I III III i O7 - I III
~06 - 05 shyw
a
Igti= 04 - 720 Mp DOMINANT ct WAVE LENGTH- ~ 03shy
02 f shy
01 t shy 1)O~~~gt~- J 600 700 800 900
WAVE LENGTH (Mp
bull
bull
bullFIGlRt IO- COJllPIUlItiw ~IW(middottltll tlnIlRlllii-lion (II (IllP( 101 1i11(1 olllhinulloll
with dominllnl Il(lllllgths at 720 and 7iO lUi
bull
bull
bull
HAPlD PHQTQlfE1IUC JjETER~lINATION OF Rnmrm AND HEtiINi 25
mitted (spertrophotoll1eleL lCuding-) Ol light (1 (tClcrl (phOlOshyJluol01l1et(L lcndillg~) i~ StlhjNl to (hangl
]fjt~l1le 11 and l~ show that ill til( (asc ot tJaugtIllitteltllight llJHC th~ (x[llliHlllIlnl (oIHlitiOllS tllpl j lilst n dtlln-e ill Pll~(lltngl or UllllslllittnlH( follrnY(l by It ptJiml of lClntin stability with only sliuht (1111 tHn- a f(Pl a lIt1ll1btJ of minutes The light t UIllllitblllll t l(1 ill(Iln~(s This lIIay IJP llllllJltlli7P(ll1 ffl II ow 1Ilt )( f(( darI oliIII tIIlIlNlIlitt(IIIlfJIIlh (iditilIiid Ilil1 pllIipintnl )uoshyIn Of ( 8inx in (~f1( I~iUII i~ Ild stahl I 11 itlll If 1inl nh prlshyilli(ioll of 11l1d(1 II IJIX f) jllIli II (fJJltfiIIlilty slllMI IIriot 1) IIIPldUnl1i tll(I1I rllltltilJl oj tJi~ Jlt jiot IUN ilUf Jxl1 will tIt( tOWI IItlllilil I 1llIlllblJIol I ill I~11l11111 d ill till ifjuids JjOI scnttplltl light 011 till phololltHJIOIl1lttl till dilPCt ion 01 elangl b tlw IPrfIi (If that illrli(atPll rOl tlulll1Jittp(lliuht It Itlll b( llluliJr I-(Pll that if l(middotndlnJ- IIIP mad n itl I t lIP ~()ll1d()lb lpalll this pllioJ of nmiddotlatirp tuigtility tllP llLot tIOllt thi Olll(P (nil bl IPdUCld to tIl lltini III 11 Ill TIll l~adiltg (illH~ bbll Oil tlHl datn rUl lublwls and llsinlt Illl ginll ill tnhh
50 r----------------------------------------------- f shyZ
~ 40 ~----~W~A~V~E~LE~N~G~T~H~7~5~0~M~P~~~~ ~ --------------------=-=-= ~ 30 f- WAVE LENGTH 540 M~ _z _____ ___ -=- __ _ ~ ------shyt ~_=---=-=--I GUAYULEIII 20 -Z HEVEA ltt II KOK-SAGHYZ f shy
4 6 8 10 12 14 (6 18 20 22 24 26 28 30 STANDING TIME (MINUTES)
FIlirtn 11 Emmiddot of wav hll~rh Il li~ltr tlall~lIIit1alHl aftI IUIlItHt -Imlli lug 111m for guaynh llmiddotn 011111 middotiolIlJh~z 1111111 llijlitul1 flolll 1lHlh~ll1Jllryl k11II11l ~(lilltlll h~ lwitlitll 111Inu1 111l~1It1 2)1111 o1U11111 (Helillins on (illllun tlunhll IlIIJlllw]ntllW111 lutl(I[lholtllllltlt with ijUjt Wlnl IHI Ilf1 I
11 EFFEGT OF Hbli 1 -()JXT10~
Tilt lnblwl ~()h(llh pxtnl( till IPillgt ubo It 1m nllu1- bellt -~atea thut ~lll 11-111- tUP olnbhmiddot ill middottIIlIlOl ~1It tlWIIJI( my U)t PIl (tlIHatcl WIth tl1l lullh(t I tahle lJ 1hln 1- -1111 tIll (llllstlOll of nny p()~iblt tITptt of XtIIl11 diflp]lws ill ((JlllPllttUliollS of 1l-in lil lolutioll alollJ with till 1lIltbpl TIU data ill wbh +ho on tIl( hn~is of (olorilllPill ladillU thaI tll( IIUOIl1t of lnbbll Plllipirntld 110111 Ilwthyl olnlld kptOlll olntioll IJ 1li-jHlllnt 1l)04 in 1-llltlIllt ethallol)- not amlll hy thl llllNlI(l of llvin aU1ouut of llins inolution bull
-----
26 rECHNICAL BULLEfiN 920 U S DEPl OF AGRICULlUHE
100
90
80(I) C)
z Ci 70 UI a 0 60 a ~ UI ~ 500 ~ 0 I Il 40
30
A 20
0
100
90
(I) 80 C)
z Ci 70 UI a 0
60a ~ UI E 0 50 ~ 0 I Il
4-0
30
B 20
0
--
--shy ---shy---
2 4 6 6 10 12 14 16
---shy= ~ ~ shy
-
2
025 05
10
15
20
25 -30
35 40
SO
-60
=70 80
16 20 2224 26 26 30
OS
- 10
IS
20
2S
30
35 40
-50
-60 -70 -80
bull MGPE 25-ML
VOLUME
bull
MGPER 25-ML VOLUME
Florm 12-EtTld (If till1l or Slllldill~ 011 light transmittallce (01 (A) gUllyulc lnUIl(I plccipitllitd frOIll llltt h~l isobutyl Ielollt solution Ily neidilic(l ethanul bull null (B) gUllyule ll~illii pre(ipitated flom aeltoll~lllcetOlll-Cl])osolY( 3-7 solushy11011 by H(illilip(i l1U (HPlldillg~ nt -lIlillult Ifllpluls 011 Evelyn photoelectric colorimellr with jU-lllp tlllll alit U-1I11 npN(lle spp also table 2)
bull
bull
RAPID PI-IOlOMEllUC DElEnMINAlION OF RUBBER AND RESINS 27
TADIbullbull ] 4-ReZation of amiddotmount of middottbber pleeipitate(Z Oln metltlIL isobutyl ketone 80lutions by OS-pereent H 2SO in 95-pere(lIIt ethanol to umollnt of resin8 udde(l U8 indivute(Z by colorimetrio readinU8
(Rubber ami resins cnlculntcd on bnsis of amounts in 5middotml ullquuts of extract from 02 gm of tissue in a 2fllll olumo( bull
Hubucl r~cocrell whcll rcsins nddcd as IndIcated Htbbor al1dcd (pllcollt) ---shy
__________bull_________ ~_12rpcrc~15011crccllt 7511crccnt IOOpcrcent
PerCtllt ercellt Percellt Percellt Percent o o o o o) 50 250 263 252 25000 500 500 500 500 700 750 750 751 749
1200 1250 1250 1250 1250
EXTRACTION TEMPEHATURE AND TIME
Typical experiments to detllmine the time required to secure maxishymum extmction of rubber und ltsills at 115deg U Ilre sUlIlmarized in figule 13 the solvents used-methyl isobutyl ketone for rubber anrl Ilcetonylacetone-cellosolve 3-7 for resins extraction-are very eflicicnt since under the conditions indicttted maximum values were secured after 30 minutes of ext1llction The most eflicient liquid for the bath (lig 1) used in extrtlcting rubber or resins is ~ high-grade cylinder oil (S A E ~O) The sand bath and such liquids as glycerol have proved unsatisfactory
RUBBER AND RESINS STANDARDS
According to the National BULeau of Standards 1-_ lhclc Is no gellcrnlly recoglllz(d standard lIIutcrlul [ior II rubber standard] The rubber hydroCllrbon ill llifferent samples of conmlcrciul smoked sheet or pale crepe from heclI pluntlltions nries from l~ 10 04 llercent of the totul nutletmiddot the most 11Ioruble conditions Of preparation
McPherson () has described a procedure for the pLeparation of pure heve~ (Hevea brasiliensis (H B K) MueH Arg) rubber from crude rubber or latex In the absence howevcr of ~ generally recogshyn12ed stalldard for rubber hydlQcllrbon [caoutchouc (CnHUs) xJ the standard adopted was that of the relnthely pure product secured from gunyule tissue txtractiotl nccording to the Spence-CaldweU method (5) or the motlified PIOCCdUlU of Hohnes lind Haasis (p 2) The details for constructing the calibration CULes are given on page 10 Standard rubber samples apparenl-]y can be stored for a long timc under the conditions des(libed on page 10 The duplicate colorimetric lendings for glULyule rubber newly extracted by the modified SpenceshyCaldwell method were ()J2 ench as compared with US) each for the sample extracted by the same method but stored 1 years In each case colorimeter rcadinllS were made on mixtures containing 2 mg of rubber in It 25-1111 Yolume
The selection of tt suitable standurd for guayule resins presents some dilliculties Tll(~ acetone extract of gUllyult estimated on (l gravishymetric busis~ for instance proved to be variable depending on the type of tissue sampled or season of sumpling because such fractions as
COllllllunlcntion dul(lt1 Octohtr 22 11H3
28 QECHNICAL BULLEQIN 920 U S DEPT OF AGRICTTIIlURE
16~==========================115 shy
14 bulli= 13 z ~ 12
ffi II Q
10 c w 9a w
8gto () 7w a
6a w
5en III ) 4 a
3
2
A 00 5 10 20 30 60 90
14~------------------------------------------- bull13
i= 12 z w II ()
a 10 w Q
9 c w 8 a w 7gt o () 6 w a 5 If)
z 4 If)
w 3 a
2
o+B~~__~__~____________~__________~ 5 10 20 30 60 90
HEATING TIME (111 NUTES)
lllGUltE 13-lDffect of time o( lICntillg O2-gm samples of gunynle tissue with solYlIt nt llfio C on lo(OVl)ry of lllhlJer alld 1Isim Lt HlIhblL extracted with methyl isohntyllwtone B resins Cxtll1cted with aCftonyla(etonc-cellosolve 3-7 bull
chlorophyll are weighed along with the resins in the acetone extruct but are not estimated by the present photometric method (fig 0) 1he use of a diffeJent stanclttrd waS therefore indicated
bull
bull
bull
RAPID PHOTOMETRIC DETERMINATION OF HUBBIm AND HESINS 29
The resins standard selected is based on n relatively pure source of resins the rcsinous exudnte 011 the stems of guuyule plants IJldimishynary expeliments with the resi nouS cxuclate from diffcrellt gllayu Ie strains of various ages indicatc nHlt there is little YaLiation in this subshystance on the basis of Colorimct(r readings 011 2-mg aliqllots of 01shypercent solution in It 2i-ml volume (tabl( li) Expelilll(lnts have shown that the air-dried (xuclate contains 3RtOH p(Ic(nt of -volatile matter This material is l(latiyt~ly stablp ill (OlllpoBition and is npshypurpntly on ly slight ly hygroBcopic as shoWIl ill Ia bl(1 1 Tlrp Ipsinolls exudate may be jJleplpd in two wayi-i fl liSP as a stallClHld-(l) the clpan exudate is clripd iol Ghouls at ()1deg C at W indlPs of a(lIum Hnd aftclbCinOglOund ill a molfalis 1)I(spI((I intn airtight COllilinel OL
(2) tllP Cx7lclate is clissolllt1 ill a(lhllll and filtplpd PlactieaJlyall of the acetm1l is thpn lYapolntwl olt OPI a stlam or atCt hath and Ow residue is dripd ground an(( PI(sPIld as ill tllp fin lllethocl Tlwse two prepalHtlolls a1( (ompalpd in ta hlp ) 111( (((tails fOl ~t()lil1g the resins standald and (onstlllcting the calibration CUITPS alc given Oil page ]2
lAIIIg fi-CUIIIllrsoi (lJ lIr-dr(1I IIIIi 1((11 II II-()I-tr((l l(sil~ 11111111(8 of I II 1111Ie
[Colorimetric rrndill~s 011 1~I11 phulll(Iclrie eolorillJct[lr with i~()middotmll (100- to iiOIIIIl) fillcr [lnd 5-1111 lIperture preeipitantl part ofO5middotPIrctllt 10 to 5 paris of IIOj
nupliclllc(oloritwt([
nIl(lin~s (hIlSlcAg~ ofSlmillXo JrNliltlCllt of fPsiJI$ L1Xtlrlntp on 2 IIIg ofplanls fllsins (XIHIIlt~Jwr 25-1111 vol
tII1(1) 1
leflTs Various _ bull ____ bullbullbullbull 3-9 Colll)Josiltrlairmiddotltlricfl bullbullbull nf)2 002
])0____ bullbullbull _bull __ _ bullbull ~-l Composilld (ri d at n5 C in aUmiddotimh lWUUllJ for l (jOuj(ja hours])0______ bullbullbull __ bull ___ bull 3-0 COJIlpositld disso]NI in neptolll f1l1erNl fl(lf()ll( GGO i(jO (Ivaporntld olT OV(1r Stpl1l11 halh TesidlH drl(ld I1t fi5deg ( ill anmiddotinch VIl(Unlll for 0 houlS bull
middot106 __ bullbull _ Jir~c1rild_~_~_ _~_ ~_~ _ ~ ____ _ __ _ OUu GOifina_~ ~ _ ~~_~ ___ _ _fln~ ~~ ~ ___ ~ __ 6(imiddotI tiliA H)[_ ltlu bullbull i18 tisSflOabullbullbullbull__ bullbullbullbullbullbullbullbull lt10bullbullbull _ tillO llitO406__ bullbull __ bullbull __ bull __ __ lt10_ Utl2 fon591_ fo__ bull liGa oOa 406bullbull _ __ lt10bullbullbull_ li5S OM
j Ph( vnluls in Uw Inst COIUIIlIl indieatp thnt gunyulp fesinous (IIHlnt( wlwtlwr dfircl hi Yn(tlLJ1l1 wilh L~ perc(nt loss of volntllt wutl pr or tWl c1rild giVPd npproxil1lnh1ly t Iw snllw colorinwtCr rNHiing- 011 till busis of aliquot~ cOlllniuiug 2 IJI~ of flsillS lXIHlntp l)tIf 25-mI volultl( Ihil- illdicate~ thl11 Uw UITW IJ1flS~ of olnshytile mntl(f prt~(iJlitnt(d gins npproxilllntlly Uw $1II1l (oiOfirnl1tlf ftudiTlJs ns tho ftsidtw A pnlill1jllaf~middot (XIlltrinllnt indicutls thlli th VUllltill muller l(lIlSists of thl Ilrplne oil fmcl ion I5-(1Il gtnplls or rlsitlOtlS (lxudntll gnvll by stPll1U distillation nn Uefllgl of 011111 of jl(lfPlIW oil with npproximHte tilllsity (If OHIi lind lhus rrprlsll1ll( IlPIJroximllt(I~ 01 Jerccllt Of t he original weight 1hls lllrClnlage complrcs wllh 38 llltrC(ntlost by drvinI( in IICllnllJ
aSplusmnUH perceilt or orlginlll weightlosl
The wailnble illfolJllntioll on tlH (ow-JitlPllts of the gunYllle r(~shyillOllS exudate alld tl1( HeetOlIP ext act of gaylp ti~slw is sllIllmarized in this paragraph lYalttI (u) alld also Hangcn-Slllit lind his coworkshyers 16 reported that 20 percent of the resinolls exudate from gUltyulc stems is parthenyl cinnamaie (CHuOH=CHC020 11JI2r) Steam disshy
15 (OIlIJIIIIUicatioll flom A T Haai(II~l11it llId (0011(11 Calif0111 ill Tnfiitnte of Tccllllology Past(IlIJI Jhps( wOlken al Htud~ing the COTlHlitlllllts of the acetone extract and other conlltituellis of guuyule
30 TECHNICAL BULLETIN 920 U S DEPT OF AGRICULTURE
tillation of similar resinous exudate in the writers laborntory has yielded approximately 4 percent of the whole as the telmiddotpene oir fracshytion Haagen-Smit and his eoorktrs nportec1 thttt about 25 percent of the acetone extract from guayule branches is parthenyl cinnamate and 6 percent of the bark (ltortpamp-phlotm) extraet is parthenyl cinshynamate These workers fm-thcI reported that 25 lwletnt of the nc(shytone extract frolll bLllllches is a compound with the tlI1pilicaL formula CBoH400a 1 percent is a compound llwltillg at 2P to 2T5deg C and 1 percent of the extract from the ]eav(s is tl (olllpoulld nwlting at 100
to 1710 1Valtei (6) reported that 3 to -l perc(nt of the tI(eton( txtract
of leaves and flowering StPIllS of guayulc eonsists of waxlike substances soluble in olgallic soln~nts but insoluble in at(l and (on(ent1llted H 2S04 The flactions mentioned on the basis of (onHLTutle esti shymates of amoullts actually isolated tlecoullted for about H ptIcent of the totalncetollt~ so]ubles extracttd from tll( guuYllle 11 rub The other constituents ltlilaill to be i(](ntifi(d
RUBBER AND RESINS CALIBHATION CVHES
Typical culibndioll Clllves iol Iuhbpl and I(sins bas(d 011 (ldtLminttshytions made nccoLdillg to the plocCdmC outlin(d 011 pages middotb to 1G arc shown in figulPS 5 and 1+ The spCdlopliotoll1lttL en (OIOIjlllctCI readings are plottCd on s(lIlilogalitllllliC pappi ag-ail1st (Il 11IbblI (011shy
100 ~ 90
80 ~ 70 ~
z 1amp1 0 II 1amp1 IL
1amp1 0 Z
60
50
40 ~ltI 30 ~ en z ~ ltI II ~ 20 C) ~ oJ
10 o 2 3 4 5 6 7 8 9 10
RU8BER IN 25-ML VOLUME (MG)
bull
bull
bull FI(lURE 14--Ctlihration curve fotmiddot gllftYlIlc lubb01 (Hct(lings Oil COIPIIHlII tlOl1hl(
monochromator SlCClrophotolllet(r with 7fiO-11IL Illtel alld Hllp Wll ( IHlll()
bull
bull
bull
RAPID PHOTOMETRIC DETE~MINATION OF RUBBER AND RESINS 3]
centrations From a casual inspection of these CUlTes it would appeltr that Beers law does not hold Actual tests indicitted that Beers law was applicable only within a narrow range in the upper portion of the curves The analyticlil results on the basis of photornetric readings nre therefore calculated by direct reference to calibration curves or from reference tables of equivalent values bllscd on the cnlibllltion curves
Calibration curves for kok-saghyz alld heyea lI11tulltl rubbers and Buna S (GR-S Chem Gum IV Goodyear) and butyl (GR-I Standshyard Oil Co Protoc) sYJlthetic rubbers are hOWllil1 figure 15 The samples of kok-saghyz rubber were furnished by the Diyision of Rubshy
100
90 ~I) ()
z 0
1amp1 a
~ a
80
70
60
s 1amp1 ~ ~ 0 ~ KOj-SAGHYZ 0 l Il
50
HEVEA~ ~
40
100
90
~ 0 80z Q 70a Co)
a 60 ~ 0 0 x 50Il
40 ~----~~----~------~------~------~--~ o 2 3 4 5
RUBBER IN 25-ML VOLUME(MG)
FmUIlE 15-CaJiblation curves fOl kok-snghyz h(YCII Bunn S lind butyl rubb~ls (Readings on gy((yn photoelectric colorimeter with i20-lIIp filtpl and 6-ml aperture)
32 TECHNICAl BUIJLETIN [)20) 1 S DEP1 OF AGrnCUIlfURE
Iwt Plant JIl(I~t ignlioll of thi BlII(un and (1( l))(parcd according to 11( SPltI1((-Culd (]] (6) PIO(((lllll Hlpt pal( CLPPe was (xtmch(L with acetone blI()Ieit W 1I(gt(11l a ttnlldal(l
SEXSlllVllY Ol~ llETJIonS
By lip pIO((l(II11P olltlillP(l 011 ]Hlg( +n Iowa (lOOl IIIg (11 1111i(l0shygmm (gHlllllla) of 1hblI ill a 2)1111 yoltll1ll (all )(gt dltpltld Oil tltl Col(man (lohlP mOIlWhlOl1lHlOl l-I)((t 101 l1lOt 0111 ci( I ill1ilnlly 001 mg of Iublwr ill a 2J-1ll1 n]ulllP Illay bl Ilad Oil till EnI)1I photoshyllectlie (O]oLillllt(I Thll ya lllll- 011 tilt IHl-i- (J I (xl ad iOI1 fmlll 02 gill of til-lI tH(JI(lillg to tllP -lllndal(l jll()(pdull 1(PIPStlIt IlO()2J tlnd 002) P(IT(lIt of llIbl1ll IPI)(((inly bull1t1lollgh -lI1t low allils can be d((d(middot(1 il lIoullt1 Ill IPtllizpd thnt till PIIOl ill PlI(Plltng( or tll( al110unt dltlIllIilll(J i ltlatlpl high ill tili PIY lo Itlllgl 111 aetllllllladie(middot Ill( lopl lillliL 111)(1(1 lIw (ollllil ions of tlil ]lI()(lltlIIIl u ol1tlinpd ipt at l11 11I1 or 1111gt11(1 illt i-1ll1 Ollllll IlPIPltPlltillg 01 p(gtl(pnt of JllUiJtL un tlll 1Hli or (xlla ion rlOI11 II rlll of tisSIll
EIlIlOH COSIIlIHIIO
In Oldpl to H(IIp ill )1lHtPltt pl((iioll illlpIi1I- it i lH((SSHI to slnlldHIdiz(i rigidly 111( Pl()((dlll( 0 illdi(ntpd Oil pnglt- - to J( If lids i dOlH tlip lXIHlinwnlal PIIll is t(middotdllld 10 n ndninlllill
Illlt pl(iioll of (hI ]lIPPllt 1IHllwd Oil til basi of ]llllP llIllJt1 alld Ipsinssollltions call hI jlldgl(J 110111 figllll Hi lileh lio- til HPIlIgl d(intioll oft -illgIP lI1lnSIlIlIIIlnt in lHi((lltagl of Ill( alllOllllt 01 Illhshy1)() 01 lpsins d((PI1I1 iJlld TIl( (1101 PlI(Plltaglt H1( gi (1 101 OJ) to
RUBBER IN 25-ML VOLUMEMG) 004 01 02 03 04
i= I I IZCtOW
fbA ICtU CtCt WW a
01 02 03 04 05 06 07 08 09 100 = RUBBER (PERCENT)
RUBBER IN 25-ML VOLUME (MG) 10 20 30
~ I CtZ
bBOw Ctu CtCt Ww o I~
010 50 100 150 200 250 RUBBER (PERCENT)
RESINS IN 25-ML VOLUME(MG) 10__ __3-0_ 40 50 60 70 60 90 100--_-- 2_-0
Ct~ -r- 1 I OZ
WCt UCt b C wCtW
a o I I 150 250
RESINS (PERCENT) o 10 50 100 200
bllI 1tI W-Yllnl dtd1 ioll I I 11l1 11IlI11 1(111(11 1 III Plll- IlIIIlol1 01 IIim~
bull
bull
bull solution Il basis J o golH of tiSSII (JlILCl-nt (11(11) for (~I) (l)1 til O 1I1
of luhllpl lin 1 III I (I Ill of lUhlJPl nllll laquo I J to 111 nlg of IlSlllgt (Itllillgs on ]iYllyu pllolwh-llrk CO[IJlilll(-(PI with nOHIP Iiltlr lIntl U-lIll allcrture)
RAPID PHOTOlJElRIC DELEHlllNAllON Cn HUBBER AND H1~SINS 33
10 mg of rubber anel1 to 10 mg of resins in a gJ-m1 yolumC For
bull
bull
bull
comparative ptuposes the leslllts arc also calculated on the basis oJvershycentage rubber OL tltsills in 02 gllI of tissul As WOlllL be expcet(d the error increases sOIlHgthlf for 1(lali nmiddotly low COlHell t1llf iOlls oj rllbbeL or resins The curves in figure 1(j s1l0 that ill til(gt Illlge Ol to 10 pCrshyeent of lubber the elTOI rangts Jroll1 abollt Ll to II) ]IlC(lIt abo(~ this mlllc tIlt (ITOl d(((ts(s to (ollsidlItbly ltmiddotss (han 1 1lICPllt of tlH mllollnt ltl((Lmill(d Hil1lilally in tlH (lISl of l(sins analysis (fig 10) the ltLTor is (onsit1eIubly INS than 1 PlLllnt ill (he lallgp of 11 t~) ~() penPII t
In nil ([lSl of lllhblI alld (sins lx(Inltpd tIOIl1 (issups Ol addcltl to tisslle lxtlads (s(( tabhmiddots (i H) illyolillg ll01P o(lllntiolls the eLI01
is hig]wl thun that indilHtld in figllll ((j Im pUIl Ill )])p I tllllllsins solutlOII
COlllUCIIOXFOH IXSOLl-IlLl~ Ilgsqgt(Jg
111 th( Jllo(pdulP ollllillPd 011 paw I till illsolllhll isSII Ipidll( tflpl (xttlw(ioll is (Ptill tlw lIask l(lll till xtlct i l1wdp up to yoltlllH It is not rOllPllipnt (0 IPt()PI qWlIltitati(Ir III(lw[olH a 11(1 pllooll extlnlfs of guuyull I is-lll alll thl1l main t11l111 up (0 YOIUllllmiddot bpCaUHI sllch all additiollal stltp wottld]) tillll-C(JllS11ll1illg Th( Iogiea nll(gtIshynntin is to mnkp tltl lXtlUCt Llld Ipsidup lip to OllillH in till original flask andi llPSStllY 10 llwlno tl OIIpdioll wlHIl (allIlnting [hc llshy
Hults f(JI [hl oll111lC displupd hy till ins()lllbh llsidll( III it l)picat (IXpednHllt (ollsisting of Jhp lppJiea(iolls if was Iollnd llftt at ~iiO ( 02 gill 01 Iuhhll pillS IPill-fl(( lisslI(gt (lollpdll fot llwistUlC ou basis of dlyillp ut lOW 101 ) llOlll-j (lbp(ld only t~ llllUll voiul11P of OOk7D~- OO(lOO(i Ill of lllthyl bolnl(yl 1lIOll( (lplhlli(al-t(Tnltle sp gl () Ii I ll(Hli (j at ~)) -gtitllP tl1(gt 1It101111( () r t is-lIl xt Iadld j sl1lall til( PlIOI dul to Ill(gt insoll1blp Ip~idll is slllall III [0111 ill( wOtk it (all lJp diIpgal(ll(l
]hcon~lIY OF HllIllgl AiO HESIS AIH)gl) TO EXTlIACI OP
GlYlLE TISSlg
Tnl)ll G L(IHpslntillp (ypi(nl llld(~ SllOS (hat all a plngl of HIOK PlI((nt ot lltl pltl( Ilhl)(l acldpd to tllP Itll h iolJut1 InmiddottcJllP xhnet
of guayulp tiSI1( WllS 1l((PllIl Tlli nllintioll flOlll (olllplpU I((OYshy
PIY i within flll pxp(IiIlHuttllIIOI ~illli]llly fnbll Ii llows thn 1111 llYlIUgl of 1O(1~ ])(I(Pllt of gllllYllII 1(-i1l- add(d to II( (pllosol( (xshytrae of IUllY]l t i~HI Is 1l(oPIPI
THl~ (~ Hf (Off Ill of 1111)( J OJ I~il~ lItfI(( In ~(JI1IJk~ Ilf (111 [lI1Il fI2 lIII
0 tlUfllllit i~~I1
Instrument
---- ----~---- bull shy 1(1
Colemun ruono~ltrOUlllt()r 2t) II sJl~ctroJlhOL()lIIeter with 2tJ I iflllllI wnclength Fetting 21 II nntl 0-1111 WU HI hUJl(L _ L U
Ill 7Evolyn photo~lcclrie (olor JU [ imctcr with iO-llIl filler IV (I
H1 0 t I I
llImiddot lUn WII 1011 HIO Wn mil lUulon
10 JIg1111 IUI ml lUl anh Io aLn 111)_I ) III li lU It 2) deg wn2SU DD
Irl JIll II IIr II US II
1110(1 lULa lUI IlK) IJ WU
I( llI Htl tNI 1(111 2tlNI HI 0 221) lllil t2S 0 1~ 10 1~13
In (I 2117 I
10U 1l(J ~ 4 _H_j ___
9middotJIlJ5 10115 10 00 lUU5 flUU 4li (tl03 9(11)
leIlKl 1l~)5 lOOU l1KIr JOIS un 003 OIl Ii
34 lECHNlCAL BULLErIN 920 U S DEPT OF AGRICULlURE
COMPARISON OF PHOTOMETRIC A1D MODJIoIED SPENCE-CALDWfLL METHODS OF RUBBER ANALYSIS
Guayule samples were analyzed by the photQ111etIic method and by bull the modified Spenc(gt-Cnldwell mcthod The values in table 7 represhyselltativ(I of typical results indieate It -atisfactory dcglpe of conformshyjty between the two methods in thl range of tiSSlHH with llHHC than OJ) percent of rubbtImiddot On the bnsis of the amounts determimd the results in this runge for the plmiddotts(nt lIlcthod ayernge apploxinHltely j percent highcr
~LAIII~ 7-(oIllJl(i~on of lltlllrIic (IIri mOtllinl SJl(II(r-(ulri-wall IIIrtlwrl~ of rlrrlIIillillfl 11)1)(1 COIIrll of UI(III
1 Flowers frllm amiddotmonth-oltl nursery plants
YAIIIATJO- OF SIli(LE DETEnt1NATIONS Fnoll TnEIIllIEAN
Rllbbel (Uall8i8-Thc plcCision of thc pLcsent method when gunyule tissues Hr( nnnlyz((1 for rubber may be j udg(d flom I Ill datil presentcd in table H TIl(se dahl -how that thl pplCPlltag( uriation of single determinatiom from nwan yullles with low standllrd enolS ranges from less than 1 to 4 p(gtrlent
R(8in~ wWlsi-r-s lndi(a((1 011 page ~j he INntlts s((uled hy the present phoolllttric nsins llHt hod are not tliltly (olllpalable with those of the grtLVimetri( ncetol1l-cxtlt1(tioll II1etho(l Thjs made it necesSllry to selc(t another lalibllltion staudud-tlll Ipsinous exullate from gullyule shrub-thut gies relatively COllstlllt photometric readshyings (table 5) The resin (olltents of guayule roots branchcs or leavcs usually ran(~e from about) to 1-1middot pelcellt The ple(ision of the present methotf WhCll gUHyule thslllS lIe analyzed for reins may be judged from the datalHmiddotpscllted ill table 9 1h(se data show that the p(lcelltage variatiun of sillgle lhmiddott(Lminntions iLO11 meun ynlnes with low standard NTOrs rangcs from about 05 to 4 percent
bull
bull
bull
bull
bull
RAPID PHOTOMETHIC DElEruIINAlION OJ RUBBEH AND HESINS 35
IAIILE 8-luriation inclieute rubller (mallSM of [1wIIle tissue bll thc 1111O0Illclc metwII
Vnrlntlon~Ilbher I (rom mean
ierCtnl Percelll ~OU -22 ~ 25 +27 ~ 20 +18 ~UO -22---------1_______ 51110 0G6 bullbullbullbullbullbull _bullbull
10 ro ----=ii41075 -01 1000 +11 1010 +13
rlln HI itil 1l9~ 1_ ___ =-~~~
115511 ~ US -111 III II 1575 -13 115 b tiS -I a 111 h WlU +22IIM-(middot bull 11K -1Ja Illi c 1000 +03 1J5H1 W +l)7 ll1imiddot tl 1575 -13
Mcnn 15951 131
1102-11 21fJ() +21l102-h _ ~~)SO -17 1102-c bullbull 21CO +21n02middotd ~OIiO -26
2 r~plusmn Il~ 21151 261 I -~-------bull---__ _~~_~______l-___--_
1 lhe$ 1111($ I1n (or SlIlIIllltS Stpnnltplr PHrilClld IIrtlrdlng 10 1hr prollIlIlr( OIiIIiIl(o(I on Imgt$ 4 to IC ~tcond nUlI1 hlr r(J)[ltnts stl1ndnnl llrrot of tilt 1I1(1111
1_1l1~ n-J(lri(iot in relli(Upound rpoundsins (lllalIsfs of VIOJII( lixsue b1 the lhomillric lII(lloli
-- ---~--- - __-------- shybull I I I I Varlgttton
_________~___ ~~lu_n_Jl_Q_~~~_____ ______I__~_o~S_J frOID lDean
Percent Percentgt458-1 ~65 +41IWtl-li 130 -a2Hli8c aliO +26S41i8-d bull 130 -32
1(-011 34I10Olifgt __ bullbull __ ~--====
li-9~2n 881) -06 li-9~2-b Si5 o ~HH2middot(middot S i5 -6$-H2middotd 000 +1
8851 054
O i5 +6 9 i5 +6 950 -20 U75 +6
H-liG3o-n bull -1 n-li6~b bull __ _ -IH-IWH +4H-l61511 bull -1
1tmiddottlU
62~-lI __ 62~-b ij24-( bull OH-Ji
(-Ull
I rll(St oluls nre tor separately ~xlrflCled SllllllllCS IlctOrdlug lO procedure outllned ou pages 4 to 10 i Secoud number r~prtgeulS stulldMd error of lIe menn
36 TECHNICAL BULLETIN 920 t ~ DEPT OF A(]RICCLTCRE
ReUUER A~ALYSrS I~ CRCOE-RcuUER PROOCCTS
Sew rapid photometric m(lthod~fol the ddellllinttion of rubber and reii Hi ill uaYllp ti--ut htp lllell pIPHnl pd oil pag( ~l to In A brief H1111111tlY of It similar rnpid llHthod fm 1I1hb~rllnltlysis of u1lulcanizNl tlIldp lubbll pl(Hlmtlt whielt i~ bn-(tldo on the prill o
ciples dehtilcd tlllLe follows Duplltate nt-gm sllmph of the finely cliyiliNl IlInttlitiup wlirllll out [~ei-()l (all hl lIf((tinmiddotjv INd to lt1iyidl till alllpl) TIll kltolll-olubll portion of till )111(11( tlrc di-olved a- indh-Htpd fot thmiddot lllnkill~ of -tlllHlunlluhhll olutiou Oil Pt 1II hut tIl IUlIp Hn lIn l-fplImiddotd 10 lHI-ml rolllllltti( fln-k antil1ltld(lup to Olllll1l The bnlulUp or till JllO(ldllll i- thatutlilllll on paWs -1- 1 IHI Ii 111( 1(111 1- nIP IXPIP--pd nil til IHi or Iw oligiJla w(lullt of I Ill (I11l1p-I1l11Ilt1 1)(0(11(1
Hupitl PlllimiPJojgtiWllllllllh llIltllOd~ fOJ Ihl llPtlmiddotminntion of ImiddotUlJbll tlnd 1(-illo- ill -111111 Illllph of gutlYllll tiUl IIll dl-eli)ed 111() IlltlY d~o Ill nltlI1lld fOl III Iwl Illhlwl- and l~iJlmiddotb(lLiJlg plant TIllt l[Olllhup hns nlo b(l1l ntuptpl fot IIH lltlIll1illtltioll of lllhbpl ill 11lHhrublwl Pl(Jdlld~ HIIl 1111 hI ndaptld JoJ IIll ann lysis of ynt1J(gt( ic lllbbl[- The llllthmb HIP 1gtn(11 fill tIll fol1owill plimiph- III Grinding
tIll PIOPlly driPl t i~lIl 01 Ul tillg tIll pnHhHt to tll l((lllilllllh~lel of filWlH-- til plllllit qIHlIllilnth( lXIIHtioll 01 IIlbhlI 01 1(--IJl- () llsing oXWllutld olnuh (kttoJls IIt(talp and() fllltil for LIbbel and IH(ltIlIlyptIJllIllIoolYlnJld-o flJllh 101 niJlsl with t(lathelr high IlPililig points 111 to n C) l]olle or in mixt tIll thllt Pll mit tlll rnphllxututioll of luhll(l OJ [middot(ill ill ~() to (l mi1lutp It r(latiwly high 1lllIllllltlltP Ill to 1~11 ) l) lllllipitntillu till luhblI OL Imiddot(ill frolll aliquot () f till oltn ion I IlIlllI-i () f Hlltabhmiddot pl(~(i]litallt (willifhmiddotd lthmwl fOl IIlhlHI Hild llitlifild lllr fOJ JP-illl t~) IIlHkillphotollllliilPIIIIiIlof PlllPlltal of liht tLaIlS mittUl(P lIftlI IlIlbll (II Il in PIlipitalioll 11 II WI( Iplllh thnt (limiJlall till PIIOl dill 10 xtralllOlh (0101 (till dptl1minntinll Iph jill 011 tIll dtwlopllIlJIl of H HIli rOI1ll tlllbidity 111 hpl than I (olot rI
jJlIlpOP-ofallnlyi-I ( p(lllil1thb IIllijOI1ll turbidity or 1llt[lIinmiddotd d(ltl of jgtIp(ii(JlI l)~ lIltlkillU tIl plllltollllmiddottri( ntdillU al tandinu tiJlH~ (dlllilll wlli(h IhlllH(lill-- IP 1llutinmiddotly tnhll) t1ll1t an hlsl~1 oil the (oJlItlIlllItion of IIlhlHI Ill I(ill (lIPIipitat((L
TIll -I(p ill till jll()(Plhul HIP 1-- follOylt (1) 1l~UIIL uJ1lplls of thwl UJfJlllHl (II tliddl(l HUt dlipd 11Illtplial an lXIllltel with11 Ill of till nlnll ill t (oU tlllltIPlll[gtPImiddotatlup oil Iath at 11 Cbull fol 11 minutl I) iIP1lIin(middot(lohd til( (XUtllhllll Jltldl lip to It middotml ynlmlll til( (nlifild by (Illlifllgiuu HlId thlPl IlI nliql1ot of tIl (IalioPlllxUlltl nll Uillltlmiddotll(t to l-llll OIlIIlIllril fiuk- (1) For a trial Ilnditlg 0111 III tlll j liJmiddot~t IllHII IIjI to Ohlllll with lilt Pll shy(ilitnnl a 1(11 it 111 (Dod fill llli lIut ( ptotoJIIltlil IPtlllillg-- of pllllntnl or liuht tlUtllIlillal(I oil n (lpel OphotnJlllllI at rase hng-tlt (If 11 llJ Ill Ol It lollllil1lPtImiddott lloyidld with tIll P10]11 I 1110110shy
Ihlolllltt hmiddot Ii1llI Olllhi lIatioll for -1IpItillg UJlproXilll1l tply Wtl P ]Plwth )0 mp are HHlltk TIll Illldillg lliJtaillld fol tIlt 4-milutl tliall(~ll-
bull
bull
bull
RAPID PHOTO~IETRIC DETERIINATIOX OF R(BBER AXD RESINS 37
ing are referred to a table of equhmiddottllut~ previously p1(pa1elt1 on the
bull basis of 4-minute reac1inJ~ for tilE nmge of lot1telltlatiol1- of rubber or resins to bE elHOlll1t(led tmd gidn thtmiddot -tnnlillfr tillIP fill rUbbEt or resins aiter prE(ipitlltiol1 lwfolE photoIllNliI j(tltlill1 un IUade The r(middotnmining dllplllatt aliquot lll then HHllil up te ol1l1Jle and lpoundadillg ale marle ut the -tandillfr tiUlE iudklltll ill rhl tall1lmiddot for the final r(adillg~ -1) 111( milli1lnm or p(tCPlltllt- of lllhbpL (II 1(-in pr(s(nt are rpadholU a prlpan(l table of lquiltlput for tlll photoshymetric readings h1~l(l ill pnell e1-E on pxpPlilmlItal lhln 1111(1 u-ing as stimtlltlds pure luhbll in 1l1bbtl milllYb aIHI guaYllh ll-ill- lxIHlatt~ in resins detNIl1111lttion I
LlTERATlRE CLTED
(1) lUnSbull 1fl36 THE mURMIXTIOS IIF IOTA RE I III OOl THER llT~II
F1 bullrol IlY U(T1l0fll UfSlfi ~rrnrl r flm lt1 KEYS TI Bill Chern 114 44J-l59 illns
t1 ~ICPHHlObullbull T 1J3bull~ lUTHOO roa THE PtRInCAnu Or a(lIUl IRrIlHU It of TIn
PLRIHEU Htllllflt [ i Bill lallllall 111 Rmiddot 711middotj iIlus
I ) RHBERG P B Ul5 A METHIlO Or ~u(ronrll-nl Hi tIII rUIl[1 f71 ii illlI
bull 14 Hoss W flbull and HARDESTY J O
llH IR1ltDII Of HfITilIZfmiddotR DllIJS ltt 1 Yl fll Off gI bern JIIIlI i ~middotmiddotlf IIl
101 SPEltCE D nnd CuoWELr ~I L 1933 DETER~n-ATIOo OF RtBBER Ii nrllllpoundRBfR Iusr 1uI II1 amI
Em~ifl cttIliIa~~ r Ell i 71middot7i l11 (HI WALTER E D
1U44 ISO~nlS OF PRTlltSrr 1trHpoundV bull l UI n W lHHt (Tnmiddot 1ETS FROM GiYI l~iIl lItr Clttrn SII J UI titJ middotn9--C1 ilIu
17 J YOEbullbullr H lO~( roLORIlETRT 771 IPmiddot nl -W Yurk f H Plrwptric hmica
naly-II rimttry lUll XphHHlnmiddot~ y 1 1
11
HI) ~ fPHELolzTRf 57 111bull Lin xw Yk t H lt PhmeHt CblUlmiddot ila AnaiY~l~-(H lithrry and XIhmiddotILpfIY Y wirh enomiddot rrJlllrjr hy H KtlJnJU11 I
t~1I --- and ~ARVER L 1f41 nlua-w ~in L liLhr IS IP ll~ XIW Yrk
bull For-sale by th~ ~a~fr1nt~nf1ent Dt~c~~ogtnts-~ s t1i rArnn~ut Pn~~~ tJffieshy
Washington 5 D C bull Pl lU ~nts
____________
f
~ ~ ~
Technical Bulletin No 920 Altllst 1946bull
Rapid Photonletric Nlethods for Determinshying Rubber and Resins in Guayule Tissue and Ruhber in Crude-Rubher Products 1
By HA~[[rTl~ P IRAlB
Prilldpal phlsit)l()li~t Iprdl GWllllr Rcv(I11t Pru]-t BUNtlll fit 1lllllt l1rlll~ tlll Soils (llul Agri(IlUllral Ellgiltcctill[Jbull bullJ [J1j(ult lllfil RIU(cl ltlmiHistration
CONTEXTS
Pal I Pa~e
bull Introduction_ _ l ExpNimental restllt-ContillUP(Procedures ____________ bull __ 4 Time of tauding after rubber
Preparation of ample5 ______ _ 4 or rein precipitationbull _ Xii effect of resins in olution __Reagents for rubber analpis_ -j El-traction temperatllTe andReagents for re5ins analyis __ _ 6 tinle ___ ________________ _
Special equipment for rubber Rubber and reins standards__and resins analyi __ bull __ _ 6~ Rubber and re~ins calibrationCleaning glasware __ bull _____ _ ) CllryeS __________ ______ _- 30 Rubber (cnoutchouc calibra- ensitivity of methods ______ _ 32~ tion cun-es _____ ___ _ __ 10 Error coniderations________ _ 32- Resinirinlibrrtion curves ___ _ 12 Correction for insoluble residue 33
~l ~rocectdre for ruhber analyi_ 14 Reroyerv of rubher and resins ~ IDProcelt3lre for reins analy~i __ 15 a~ldeci to extract of guayulc
t~~ue __ __ _- 33 ~ c calculation
~Phot~tric instruments recshyCornpariion of photometric
~ of ~lts____________ ___ _ and morlified Spence-Caldshy om~nded and 15~ well method of rt1bbergxperiInamptal reuki __________ 11 Hi ________________ _analy~b
1- ~repamtion of ample5 __ _ n- lti Yariation of ~inQle deterrnina-34
e-3olvenJl----- --- __ -_ - - - __ 20 tions froUl rheir mpan_____ _ ~ 34 -~ Precipi-ants _ __ ____ __ __ _ 20 Rubher 3nalvis in crudeshy ProtecTIve colloidL _________ _ 21 rnhber prodtlct8 ________ _ 36Summary___________ _______ _Eliminating errors due to ex- 36
traneous colors_____ _ __ _ 21 Literature cited _____ bull ___ bull __ _ 37
In order to nehie-e the maximnm prozre5- ill leelllCh on the phyishyology of guayule (Parthenillm ilrgt-ntaiulll A_ Gray) it is imperath-e
bull gt Submitted for publication January 3 10-6 bull Credit is due Beatriee K Dewald main scientific aillp fill asistancp in the
laboratory fl0403s-4amp-1
2 TECHNICAL BULLElIN 920 U S DEP~ OF AGRICULTURE
to have rapid methods for the determination of rubbel and resinsl r as well as the already available llLpid analy6cal procedures for the
other plant constituents In this bulletin aee described new rapid photometric methods for the analysis of Tubber and resins in small samples of guayule and of rubber in tissues of other plants and in crudeshy bull rubber products
The classical method of Spence alld Caldwell (5) 4 is cOJ11monly used for the determination of rubbll Ilnd resins in plant tissuC Duplicate 5-gm samples iue used Vater solubles lIl( fiest lel1lOVld by boiling in I-percent sulfuric acid for a hours the extLart is tlHn tlItuen(gt(l for 3 hours and leached fo1 1 houls Ill( slI11ples HI( l1(xt (xtladed in It Teflux-type apparatus wi th HCCtOl1t for]2 hour~ to obtai n the acetolH extract finally they arB extradNl ~il h JeIlZlIe ill the sllmc type of apparatus for at least Hi houls AJtelii 1111 oi l Ol-pClcent solutton of dimethyl-p-phenylenec1iamine has 1lll1l added to the benzene exshytract the benzene is (Jvaporitld and the lublJC1 is weighed
Employees of the Intercontinental Rubbrr Co fi and of the Eastern Research Laboratory Bureau of AgliClIltlIlHl and Industrial Chemshyish and Holmes and Haais 7 lmyr uHrdmodific(l ~pence-Calc1well procedures Acc~rding to the Holmes-Haasis modification wl1ich is used in cershy
tain comparisons (1isCussNl in I-his bulletin thC size of the sample is reduced to 3 to 4 gm water solublcs are extractrd by 2-percent (inshystead of I-percent) sulfuriC teid for Ph hours (instCud of 3) the subshysequent autochvin~ is for 112 hours (i mttalt1 of 3) and the leaching for 1 hour (instead of 3) Samples [lee twn (xtractp(l for R hOllrs (inshystead of 12) with acetone in a rpftnx-tYLJC apparatus to obtain the Hceshy bulltone extract they are finally cxtraetplt in the san1( type of apparatus for 16 hours middotith bCllZ(ne AftCr 1 1111 of a Oo-pcrcCnt solution of p~lellyl-a-naphthylall1ine (instead of ) 1111 of a Ol-pclcent solution of chmethyl-p-phenylenediamine) has b((1 added to the b(ll1Zene extract the benzene is eyaporated und the IIlbber wi~hed This modified Spence-Caldwell method if referred to in thC comparisons with the present mettocU
bull The term reinH as used hpl(in r(Cel tn tIl( lwJion of the l1(et-one 0) Ilcetonyl acetone-cellosoYe 3-7 extTnrt of glll1Yl11e tiue tha I-is pr(ci]litatNl by O5-percent H2S0 in H 20 This preeipitate reprei(nls n mixture 0[ gt(Y(Ia subslanclS An inventory of whnt is kIlOIlIli)ollt IIli fmerioll if gh(n (Ill IlllgC 21 Frolll n physishyological stllll(l(1oinl this fllletion is cougtidN((l at (1refent 11 IIIl IIp(11oximnte measshyure cf the contents of the relill cannl and nny relill that mar be irw]uded in the cells The wo)(1 rCsins without (]uotflfion mark i~ 1Is((1 ill tllP t(xt in this sense
Hfllic nUlllh(I~ ill (1IlI(lltlWlClt 1C(ll to Litllnture (itld p3 bull InfOllIlation in the f1(l of th( flIlina (lhi8ion I11tll(011tln(111111 nllhlle Co
now thC property of till l K DlPIl Iment (If grienltulp bull ANALYTICAl S~CTIOX ]~AIImN RI~TOXI LAllOlkTonY Inonnllus FOR rlI~
ANALYSIS OF lIUT1IJER-m1lTNG r~TS 10 THEIR OERTETlIROIIU(1S [Unpublished] T HOL)[ES R L lind HALSIS F T NOTES 0 rlIE SIENCE-CL)WElL )[ETHOD 01
RUBBER ANATYSIS But Plaut Indus SOils i1nd Agl Engin ~1Xlt Guuyule Res Ploj Rpt [Ullpllb1ishe(11
bull Credit is clue R L Holll1PS Fr HtI~ilt lllHi theil assitnnts ill the ubber laboratory Special Guarulp ResetuCh PlOjPCt Sul I111 S Calif fOl making the bull rubber lind resins detelminu lions hr th( Illo(lifieltl Spen((middotCuldwlll method for use in the comparisons recorded
3
bull
bull
bull
RAPID PHOTOMETRIC DETERiHNArIOX OF RCBBER AND RESINS
Cox 9 proposed a turbidimetric method for rubber ana lysis AcshycordinO to this l)rocedure 5 Om of ground material is extlflcted with 100 mtof benzene for 15 mil~ltes in ri lVaring ble11(le1 or with comtant sha~ing the sltperllatant liquid is clarifieltl ~Y cent~ipoundllp-inJ~ and is maUe up to a lOU-lUI volume The rubber In i)-Ill alIquots ]s preCIpshyitated by the addition of 1 m1 of carbon tetrachloride plus ~o m1 of acetone Rubberis determined turbidimetrieaHv on aliqnots of the extract in a Fishpoundr 155-volt a c model elertlopliotomEtEL fitted with a 52) 13 reE11 filttLmiddot T011pound an(llildlllan10 pLopoeltl a 1l1OdifieLl form of the Cox method O3-gm saInpl(s of the groun(l material are extraettd oWllliht ith 11l Ill of b(I1ZellP the extrHt j (~larified bv centrifl1ing alle dEcn n tNl into a )-l1 1 youl11et ri( tlac awl tlie rEsicluE i Extractp(l thrN a1ltiitiollal time with )-1l1Ipmtions of benzene in each cas( eentriinp-inp- al1d (((calltill) of thl liquid which is added to the oriinal lxtlnet follow ftPL the lxtlnet is made up to a 15-m1 volun1e ~-Ill1 aliquot tlLl piPNtPltl into) Ill of aeetone in test-tube cuvett(s till leultillg lubhl1 ~ll-pPlbion i III ixP(l 111(1 the amount of lubbpr is (lltellllined J tll IPHIiI1 of cnttereclliht Oll n Coleman pleetronh pitotoll1orometer
The aboYpound-l1lelltioIlPd II()(Eltlllrp~ for Lubbpl nIlflly-is W(LP tet((l in the writers lahoratol hut (lid not gin prp(ip alll acculatp llsnts nppalently bp(auie of tlll natulp of tIl( rubhpl ohEllts nn(l precipshyitant used thpoundgt ClIOI cHup(lln (xtralle()lI~ eolor in tIlt Extract and the failure to contto) llflir-iClltl~middot the (hnnrl ill tlIP pilotolUCtlie 1etlllshyinS of lllbhfl in (olloi(lal solutioll Oil talHlill
ppalently 110 photomltlie IlIPth()rl fOL jeill analy-i- in plant tissue hns been reported
The presCl1t photolllPtli( lllPthod fc)J ann Iyi of rlthhlr and resins are based on the folloillf pLineiplf III (~lilH1ill tIl( properly ddecl tisslle to the rpoundgtltuile(l (1(1(( of fhHIHS to pelmit flnantitatiw extraction of rubber or 1(in f11 l1~ill o)-YlwltE(l ~()lVPllt with relatively hip-h boilinf points (115 to 230I C J al011p orin mixture that permit thr rlpld Ixtlactioll of 1llhber or [pil1 in 2fl to ~(l minutes at relatiwy hirh telHppratHlt 11j to 110 0 I (31 precipshyitating the rubbEl or [eill front ali(luot of tht olutioll- by mean of suitable rrecipitant I-ll making photOUlPtlic lpadil1gs of pershy(enta~e of light ttnnslllittarHe afteL rubhel OL resin pretipitation at 11 wave lenp-th that eliminate tht (ImI dlle to extLalJPOll (oloL (the determinatioJl relyinp- on the (lEnlopment of t uniforlll turbi(lity (1 ppl-() miller than a color for pllrpos(s of amtLY-l J I) e(uriLl this uLlifoLm tlll)idity 01 reqnill(l clerEe ()pound plp(i-lm by makin the photometric rEac1ings at stamlinf rlm( I har arl hald on the (oiweLlshytlation of rubber 01 l(in preeipiratetl ThE rrlatiou of COIwentmshytion ~)f nlecipitat~ltl rllh~pl Ot Ieins to -tnhiliry of photOlllEtrir leltclshymp-s Io dtnloped III tlptatl Oil pn14 to 11)
In rubber tlnalyis the u~e of the (lxYrfnntEll lhpnt wirh hili(L boiJing point~ eliminlltP rill II( of thr hirb1y n)latilr and toxie lWllshy
bull (ox L C A TIRBIOt(ETRfC l(~rHI)O fnR THE ~-lY5r 1F 11-1 )[ATFRULS FOR RDJIlER Rubtwr REftT( (OlTl Rpt rCnpllbllhlL 1
Jo~ES E bull T nnd YILD)L~ R G JLPID SE)([~rrlRo ~(~TlIOD FOR THE A~_Lshyysrs OFROIDER n PL-iT lUTERrU Bur Planr Inrlufbull ~oih and Agr Eogin Dibull Rubber Plant Invesr Rpt rtnpllblishErl J
4 TECHNICAL BULLETIN )20 U S DEPl Olr AGRICUlllURE
zene The solvent 11ethy1 isobutyl ketone on wl1iel~ most of the experllnental wod WJth the lubb(r ll1(tlwd Ii bas(d lH reported as nomiddotntoxic (9)
In phsiological experiments tll( alllount of nilable 1l1aietial is often vely low and lubbel ])(ll((ntats J)(low 1 PlI(Cnt- atl lIot uncomshymon Henep the 1(((1 fol Illllltl)tis lqually He(Ulntl JOt nil rnng(s of Lubber contents and rcql1iling tt 111inill1ll111 of plant lllai(lrialis emiddoti(lent It- j5 b(Iic(d that tIl( Illtmiddothods dtgt-(liiJld Oil pn(s middotl to 10 mept these specjficati(l1s In tHhlitlOll the IJl(JtClt111I(S dlS(Libcd t1wle aLC relashytively rflpid
Although these J1wthods welt ltlPlloped primneily fOI llse in rosea1eh on glHl~rule pJ~ysi()loy Ih(y hmiddot( widI ~ppli(nti()I~ riley han b(en uld til lOlltllH 1Jtul( llIlgtbpI alit l(SIIlS tlnalslgt HI an eqnal basi with the 1H0difi~lt1 SpeJlCl-Cnld(lIlllcthod in the gCIlPrul rubber labomtory Special Guayuil Rpsearclt Project since August 1043 They should alo he of ntllll in dptllIIIinin lllbbel lllldlcsins in guaYlll( bre(dillg mn(Nial aIHl iJl ollicl it ud its foJ wh iell plnnt lllatllial is lit II it((l
ROCEDUHES
PnEIAIIATION OF SAMPLES
The details of prepalation of tll( tissllc ~ulllplc are hpt (onslant tluouhollt any 1) rtiellla I I(s(allh Ploj((t Vhl11 portiolls of the same samplps are tnlwll foJ eh(mienl al1alJses h(sic1cs Il1blgtlI anc1lesins the plnnt parts alc dJi(ld ithollt PI(tlpatmlnt Yhlthpr Slpalflte mmples arc talnl1 for the otlwl analyses 01 tllP iolp pl1lpose i obtninshyi ng an estimate of the totrtllllbbel and Iesi ns tlw pIa nls Ol plnnt pnrts arp pa((d in hoiling ralpl fo f minlltps (paJJoiIN])l1 and uny lCfiyes slill adhering to tIl( SIPIlIS alc 1llTlowd hv ta pping on a table top
The plnnts 01 plant pUltS nlp sllbslqucntly coarsely ground in a Viley or otillI suitablp mill and drip to pc1(Cnt or iPssmoisture in a IllcChnnieal ltomNtion onn at (joj C l)(OIp thp final grinding A drying period of nt least 2-1 IlOu1s is IPqu iLN Ill( dried tissue is then grollnd in a ltnml11t1 mill (n llntil it pasls throllgh It 2- or 25shy111m SC]pe1 Th( mill is prodded with a ground win to Iemove stalic elpctricity fronl til slmpl BltWll1l snmplpsit is (]ennNl thoroughly by blowing with eompllsHd niL The ground samplps are tOl((l in ahtight contaimIs Viele-mouth
bottles Hh metnl 01 plastic SClPW tops are 1I0sI COlwcn ilnl for this purpose
8i11(( the J(lsnltsin mot physio]ogi(1I1 PXIlltlinPllfs nre Ixplessed 011 the basis of tllP d I wpight of hI otigi nil I Sit 1I1pJt (II)(d to (onsiant weight at 100 C it is ltifirable to (SPIPS thl finnl IlIbhCt awl 1(ins contents on tlw sn Illl basis A (OlIP( iOll fad Ol i- t h(J(fote d(I(Ishymi1Nl Oil the (inply glOlll1(l 1lotol1ghly mispel sample bY dtying snlnll rluplieate SllbSHlllphs t 1 to 2 gnl) 101 R houts at IO(Fin In ordinary
U rhp plncO( of Pl Iboiling- g-narllllt 1111111 fOI IPIJ1f1yn I of 1(1Y was dyploppd h (mplop of th IntfI(ul1titwlltai Rllhllpl ro CL r (lI(III ]Jxj1lillHntmiddot ~-24) ~PJlt 15 1928) lind nlo IlJlPlirc1 by otlWl flJIployp(s ill Intpl YlI1l~s rhis was nS(PItaiJ1(1(1 from til( fi)(~ oC Ill IntllOIltilllllal HnbbPJ (0 now fill 1110))shyclty of till U S DppuLtIncnt of Agrlcl1itULe
bull
bull
bull
bull
bull
bull
RAPID PHOlOMErRIC DETERlrINATION or RGBBER AND RESIN) 5
drying oyen hen the samples are yery snlall minimum umounts at tissue in wry small weighing bottles t35 CIll high and 22 em in diameter) are usee to (Ol1SNTe ti-ue The sumples pound01 analysis are then w(iglwd Ollt Oil tlil llalis of (onsl Ltlt dry weight at 1000 by using the factor fol 1l10isttllC COIlP(fion
lJAGE~TS FOH RtBBEH AlALYSIS
In a l111lllbpl of eases in tllis -(cti(Jll nnd the Olle on Heagents fotmiddot HesinLllltlvsi It(llllilttl-gltlde dlllllieal whielt were the best obtainshyabll during tIl Wlll])(gtlio(L fLtP indklttd These proed adequate but wllln b(itleL glatils HIe inailahle tIll) (HII he cl1(gt(ke(l to dcleLlnine lny adntntugts of lIbsl ituting p gllltlps rill nbbpl and rtsins soh-enls HIC kept ill glas--ioPPlllll bot Lt
Sollenl~-Methyljs()lJlItyl kl~t(JII(gt t(hnicalgrllll lIbOIl amp Cmbide Chemshylenls COlp is (nUlply latiII(tOIY fol 1I1ltuIHI 11IblJl1 lt is IPportell us appalshylutlr Ilontoxie UI) Although it has thp (IHIIl(fplJ it IWOIll ollor this is leSS IllOIlOUIl(ld than that of othlr IHIOIHs ((Ilsfnuls fol this lIud other rubbel -lIlrellts art given in tuble 1
lAlllE l-Propumiddotfirlr of Hfulr drubIeI olld I(~ills SOllCllts completely soIlvie in 9JpccI)Jt cUtawt
olu billt r (reshyHnilmiddot lation to weight mg ~yenI~NI~ I at (J0 C)point ~1hSolvent FOrl1uh (Ill llOlnl (IIlII(l
lUIIl ruhber 01middot Wut~r llg nlI in lusomiddot
wlter vent
Hubber sohcut c c Benzene l _ elf ~nl ILU olulole ~[NhYI iobutyl k CHltlH(JIC(J(H II 23V do
tonl LNbyllHlfllyl ketOlw (If c1I3IUIllUmiddotoCli lW r 4S U _ do 43 1 1 Diiohtllyl kNone ICH([JemiddotJjlWmiddotU(ll(I1 11 fln 010 06 45 Butyl nCltllt~ (I1roeJ(I1 12fi3 a7~ do fiS 12 ~Iethyl amyl atNnW (ljCO(j(lH1 (Jl(J1lIJ 1 IIi 3 131 lt10 13 1lS Ethylene ~IH-oI dimiddot CjlJO( HtI1O(fh _ 121 I 3J () 110 210 3
rtllyl Nlllr ~middothutyl (ther (ThO Ih 112 37 ~ tlo 03 19
Rcsins oh-cuIsACNone I _ clI C()( If I -~middotI lrNiuhll I()() 100 cetonylnclonp Cn (middoto(JJcHlt()(I WI I ~H tlu UKI llJO EthylD( glycol mollmiddot CHUCUCII0H 13[1 rl2 _10 1(10 100
oNhyl Nher (((lIoshyFohc)
Diethylene gly(ul 3u 7 1111 ~flo lOU 100 mOllohutyl Nlltr Ibmyl carbitol
I fncllulbullbull j lor rOllp3rison lnly
RIlJJIIJ1J( (illituliIlQ SOIIIUJII Oi-I)PtcPIlI n~() (c ll rellg(nt Ill Pont SP gr L~H) oluUolI ill JJ-ptrtPlI( p[buJo Ily ulullIe iR upd as a lUlJbel Illpd) tall r
lrue(it-c Colloid SrltlioJ for RIlJIII A middottipcImiddotPllt iulutillu of diglycol stellshyInte S Or glycu~ttlill a retllJld g)1I11 ur tlid)(middotul nlmt Hot llYailllbe (luring the war pellod) (bUIll tlellnj(IIImiddotIndt Ulycu Prot ItI (middotu- I i IIllHlt ill lIl0lj)homiddot lille (lecbniC(ll-glu(p EusnHllll I TIll slJ(k ur digl)( [ptrlltp ~ ued ill these expfliruellts on till bUSh of tim (htPlmiulltiom nt iJ C IYIIS illO(i 1-ereClt solub( in lll()rptvlilH) rlJe diglyt1 f(Ulute 8 i blOght U(II lllutiOIl by heating tll( oluuolt is made up 10 olmn I t a tandarll tllllf)(rtltUle (25middot
J Z30 King ltrcet Brooklyn N Y
6 TECHNICAL BULLETIN 920 r S DEP1 O~ AGIUCULTUHE
in the Writl Inborntory) al1l1 fiUerp1 A [j-I~re(gtl1t solution of this by volume is then made it thu k(tone Htptate or l(hPI or tht llIixtlll or tlH~p I~lll as tlw lullber foinnt
REAGENTS HHt RESINS ANALY3IS
Resins SUITIIN- Illixlule I)f a parIs ot lll(IJII~lIllII(JIll Hlld j pnrl~ (If fthSi IllI glnmiddoto] IlHlll1I1thII Nhpl (l(rtiIlHft(l 1CPIlPi i 0 as (middot110lt01middot1 I hr 01111111 botl t((hni(ul-glu(p CnlilOlI amp VHIhi((I h(lIli(d~ COImiddotpl is a gooe1 r(sin~ soiYPllt ~Ihis lllixtlll(I i~ 11(111( (0 ilS 1((loll~Il(ltlJlIPmiddotllll(Jllmiddotl amiddotmiddotj ill thl ((xt (011shys(allts I)f thf~( a 1111 011](1 rl~ill oYlll(s tn )inlI ill lalJl1
R(IIrmiddotpimiddot((middotJitlltill1 iWiIiOl- [i-(J(middotl((middotClImiddot 1I~O (e p (agln Oil Ponl f1 gl 114 J solul iOIl in HO by 0111111( is UStl m I Ill llills pll(ipita nt
Po(- i ( (ol()icl ~lJ11I1 iOIl Ol t(8Iyen-A O-IlPI(lnt olnl ion of (igl~((1 Rtrl ra i ( H or gly(o~t tlill I lIIath ill I (p( ollyln((1 OIl(middot(plJool( j or nlly ot Itpl rlsills solnnl 1I(tL TIJl diglYlol Hipn Ill ((i ~ is (lis~nlaquo hl 1 Itll tillg Illl lolLttioll i 11111111 liP 10 ulnnl( nla Ht1li1l1H11i tl1Il1ltIIItlllP Hilt 1IIllI((1 If thl -oll1liol1 liOllltl )(lOIllI loud) II((IIIP of II drop in ((IIII)(IH(III( 11( plPtipinll may hI hlollgltt IIHI ito ltulutioll hy It(lItill~
SIECIL EQrllIE[ Fon HlIlImn 1) HESS AALY5IS
11I0T())t1~TIG ISsTH L)IEITS
8((1111 tylllS ofi IlstllIIllllltS i Ill 1lid i Ilg tltl C01lIllflii e ] (((Ioni( plW((lJl tI OJOill(hI (oJ II1Illll dolllJltmiddot II lOll el(h1011111 t OJ SPII( IOplJOtollwtpJ Klett-Sull1llllrSOll o1olillltlI and EnIYIl pllOt(l(h-tJie cololimettt han b(PIl II~~(I TIll pilotoflttolOIlIltll apptUPlltly is llot suited for thl pUlposr iJltHlIP thl (hllJlIh~Jjstj of n( l-ollsplllliOlI IlHHStl1lll waS SLl(h that thplp WlIS velY ltLpitllhullge ill the rendingS oil standing of the liOlllt iOll a1tlI rubbl1 nnd Il-ill~ plltipital iOll fltP onitL of prefmiddot el(llce fl(lIll tilt ltalldpoillt of gllntls pllri-iol1 of llading~ is us follow
(1) CoWlIlan dOllhlt 1ll001O(ltlIII1lH I01 IWl1 Iuphllt 0111(1 PI mo(hl lOH 0 COPIlHlIl I1I1iY(lsnl SP(ctI1I11holl1nHt(1 Ilwdll 11-WaYlmiddot1I1g-1 It Rlllinl II t j() mLL is IlCIUlIllPlldl(i
(2l EnblI pholo(lptlli( (olulilll(Il1 wi It (Ining- 1II11 110(IIIUIlHl tie filt lr rOIllshyhillatioll jtl lIllL 12middot112UGc51- villstllt (ap i~ ~(t1 10 ((Jlr nl)lOIptioll IIt tllllP Wlllll 1(IIilll~ HI hlill 1lI1lt1t A nitmiddot fill holding 11 Itlllll nmgllifing IIHli til flllilitatt lIlaldll~ IIPPluxilllllll 11llIII11111letl1 I(adings tn 01 lila) hc IIJ1l1l1fll(lllld 10(lllIy
(H) KlpttmiddotHlIIllnllISOIi (OI(lIilll(tP-So ~Ililllhll Iiltpl (lInrllinnlion of IIPillllXimiddot nwlcls 50 IlIJL IIln( (Ilgth I atillhl( at 1Il(middot~(middotIlt Till ill(ItIIlWllt IWIfOIIlIS Hn tisrt((oil~ wit It th( IlIa iI II 1111 filt hpi ((11 iji 111111 njij IIIl for IlIlIlI(I II nIl1~si on 2-S(tllolll (Jl oltlll glltllh 11111 (prilll wit hlt l(lJlo((1 a 11(1 f(IJ~ currentmiddot plon ~1(jlh (101l IIII plnn[ with 111 t (1 ahlllp W(J IllJL 1l( lig Hl llIi 1illlit it USP(IlII(S$
ltOl the JlJ(~(Il( tlt( Ewlrn pllOtolIl(1 de (oIOlinwhl i 11(Olllllll1H1(d as (hI IlOt eOt1PlliPllt alld ndaptabltmiddot il1trlIl1lnt rOl rout illl lnbolttmiddot t OIY alltl ly~(-
OTIIEH I~QUIII~YI
A lhplllIoI11 i(ally (oll(lollltl tlil huth wilh a l(llIun1l1l (1(11 hllsk(t pllllimiddot liOlWl [0 hoW il)Il YOllllllPI( lIa~k~ ltig ] L llihglmiddota(]( tylil(il oil ~ K O i1((1
A tlt(IHW(1l tielHr (mil 1lIl1td 111 Ipl 1Jr t It IIIIIjdlt wir It lHolol iImiddotI(1 Illld IClllollhl ~(lllI IlIl~kl[ 1111 lt it jllll(( t h()1( i II Ill ltlOmiddotml Yonnrp[ riellllisl)I 11( in stnlltIItlllllg I Ill I lPlI (II 11 of IPII)(l1tlt Hila IIn)UIII of (xIII(Itl saJlpp~ Illkpl1 (01 Ilnlll~~i~
bull
bull
bull
7 RAPID PHOTOME1RIC DElERlHNATION OF RtBBER AND RESINS
bull
bull F1(rJm 1 ~ UIIIltan 11l~IIlInIPIII lo UIIlallt-lllllplalul( ~(II(Inl-[lllrpose hath 11fil1l liS au oil hath Xlltl ~IHinl 1(IIIOIullll win 1Jt[PI 101 holding ~[j-lJll Yo1U1l1plllt flask dUIlng- (xu iOIl ur luJhl t IHI IIill IlIi is uot stlludard ltfJuillll1ll1t nIHl 111lIt hi 1Ill((1 b1 (hI Hllal~-t
Ilm1ll E JIItnslIlPil iIIit (111([ (Iltaslll(11 [1111 In(J nlHI K()(lak electric tinwl Ilw Hutpl H~ 1l~Id ill I1PIIIllIillillg )1IIIdillg (illll n((uInl(l~ 111 111lt minute unll luhllpl HIII1 Isllll al( l11(ipIIIIlP(] 111111 till tOIlIlPI 101 tinling hlHtillg nml (11 tli fUli Ilg 11l1iulls
AWill~ 01 It Ball amp I(wpllluill fol Ull initial lWUSI glinllillg of gtllyul(l UsU( Hoss-llal(]pslr IIWllifillIlioll of Ihl lInlllllHI 11Iil I I plIlIilll] with Xo 1
(~middot1Il11l) nl1d XII (iIIlIII1 (lPIItS LYIPX i lUl(l lOOmiddotml oInllHUilt 1IlI~ llloidltl witlt grolllHlmiddotglns RlOPflllS spr-ial mIIIi 11lx ItitUllIti IIllIkll wllh UIlI illlIlp 1111111 1111(1 gillS
10(1 12 CIIl iclllg h~ 1Ii jlll ill Ilillllllitl wHit gtOllIHI UnllIIPti IlId 1 em In dillllllll fOll1~p illlllllldllg lIbhll slutlon [fig A IUHllJ) 11)( jllpiul heakcr I lIJIIlI1fIIIIIlII11 t101Il Ihl W-1l1I lldUiIl low-fllllli 1IllkI wilh s[lout laquo(olning (llas WIllk Xo 11111(1) Till ll (toul I flatlll1lt1 hr (Ill lgl1lu glllliliIIOl[ing Plo(Il1m Ill IillltllIllI 11111 of Ihl gIllgt ruti aIHI IIIP sUIfa(( lit til( lIat insitle hottnlll of IIII )11111 nl( gIlltlIHI toglll)I wilh Itll(I~ ill 01((1 II) s((Ule the most II tisflnlory SulfH1 rill lil Illl I iOll
P~I(X WIIlIIt glI III 111( ll111L ill thilkms 10 II~( a It tIHS(~ III ([hiding luhl)(I Sfllll[llp
A Iolk Imil fill lISI ill diiltlill~ luhI 1111[111 H(Hy(Inl~ 1~T(lX 10middot1111 gllhmlllI (Pili Iifugp t 111H Ill]lillld wll It (011(1 1101111
lind (ork tupp (0 tit I Ill 2 ()
bull Filt1 tilk (fig 2 IJI 101 1)( with Ihl glltllunlld tublS ill thi o[WIati()n of
llOUling lIIIlillpli lx(nll illf jIIlI )lhIIIl1IY(I lIask IYIIHIlt ([illlluin l(slmiddot Ill At hp II11IPI a )Iuss lOI wit h I tIaltllll(l (lIll lIlS lI1ullIfnlul((l ill the Illhllln(()I~- fol this l1SI bill ii In (lilli(ll1t 10 -1(111( II PIIpound((( tit Howlwei tlte anilnblp filtpl ti(klIt1 tlll 1)111)111-1 lind was Intll lIhs(i~llll(l The fritte(l glass disk SII(S 110 rUlli1 lUll Ill llIlI in tliH O)IlIUlhJll hut hollis hlllk the liqllid II nil lPidlH in till ((111( PHill
Cuullipl(1))ipp(ll for tlllII~flJItng klotlls nnd uthI IlIgnnk Illnnis SlIInl pighin) III I (h li (Ill high alHI (III ill ([111111(1
8 TECHNICAL BULLErIN 020 e S DEPT OF AGIUCUUlUlUJ
bull
IHHH middotmiddotmiddot~Ollll of the ~Jl((iHI ~lnsswlI( reshyquilpd 101 [lh)lI and I(sills tllal~sis (lllss rod wilh lInttPIH(] (ml Loll alld tlitulatioll lJlll((I II]) 101 liSP ill bull IIlnlln~ sto1 solutions of IlliJlPI (olII1i lwanshydlltr -AIIlI lYIX ((1I11ishyrllg tulJl wit Ii 011( poillt (0) nIHI flIIpI stie ( J) I fOlllSP ill P[)lIill~ utl (llIdiIli (X( lels witlt shyout di~tlllhill~ the inshysulilhll Ipsidlp
bull
Glns pound1111])(1 ) jlllll in ((iamptl for 1( ill tltlm~rprljlJg- pighpll fllJlplpS HIIl1
bull (lnrin(d IXIIat to -llil ohllnlllI f1aI~
i(p-mollllt gingt hntl will llntit OJ 11I(lal J(IP (n] fOI toling- gIollIH plallt samp(
Halmiddotk for hllldhlg ill-llll middotPIlIlilnp nlHs IIIH ~i-1I11 YOlIll1pllit flll (Jig- 31 Alltolllnti 10(1-1111 ~middotI(lX IlIllPUp of IhI fq)p llsltd fOl Iitis with intpl(middothallg(middot
nh1t H(JlIlHI joint 101 rl1phl lPfIPIIIlg (lj 1lIhhpl fllld 1(ill lll((jpiltlllls
bull
FllilHE Had Iqllind fool IIJI(lill I 11 (111111111laquo llllmiddot alHl (I) limJ VfIlIlllllJi( tlak~
bull TIll itl1jHlIlWI of n Illb tlpl of d(Hdill(~~ III [gtJ(Jtnllllllil lllll~
i dblmiddotwmiddotpt hy Y (J( I _ j J i) t Illt riflllmiddot t tth~ n n Ii 11 111 h111 I t1loOIlldy witl nap lllltlIHI 1111 1l1id bpll tlll- HII lill(ll with (jtt11lill olutioll Hlld ltll If fla k It It [lllijljtnlld 111bhll nl
11ill lIll til ~tlllld all 111th Ill lillI Illmiddotforl 111l In 1(11 it j~ luhmiddotjlIll] 10 1111 0111 ilH (111(11 11[ Jpli~ Ii tllp wall TIll
10 TECHNICAL BULLETIN 920 U S DEPT OF AGRICULlURE
25- and 100-m1 volumetric flasks arc rinsed two or thrce times with tap water and then with cleaning solution al1tl watel as is customtny In all cases the rinsed glassware is dried in an inv(ltell position at 100111 temperattlre 01 upright in a drying oven The flasks used IoJ extracshytion of rubber Iron1 kok-sagh)z (Talllrl(((IM1 kO-8aghyz Rodin) are finally rinsed wHh the solvent to be used and are nllmnd to lt1Inin and dry under a ventilated hood Cuwttes 01 absOlption test tubes nre handled and cleaned aH directed by the manufacturC)s of the llhotoshymetric instruments used
RUBBER (CAOUTCHOUC) CALIBRATION CURVES
GENERAL CONSIDEHATIONS
The lubbeL hyclroc~rbon stau(ild is pllpa 1((1 by extracting the rubber from guayule bssue ac(ordll1g to tilt SPCI1((-Caldw(llmethocl (5) 01 by the Holll1lH-HaasiH modification of this method (p 2) The air-dry extraeted ltlbber is dried furtlllr in It vacuum OYCl1 with 30 inches of yaCH1Il11 at 63 0 C for 4 hOlIlH Till rubhlI sbindanl is preshyserved h1 It clos(cl contaim1 sto1(d in It r(fligellltol BCfole th( samples nrc weighe(l out the unopened cOIlbdn(l with the rubber i~ brought again to room tllllpelutnre
Two stock solutions each in triplicate from separately extractml standard rubber satnples nre prepared-the first sct of (-111(( containshying 01 percent 01 1 mg of luhbC1 ])(1 lniHilit(l and the other 02 pershycent 012 mg of rubber pel miJlilit(l TIl( (I(~il(d w(ight of rubb(L contiiinec1 in It known VOlIl11e of th(~ solycntis withdrawn Irom Il
burette or pipetted and made up to 25 m1 the standard volume used throughout the procedu]e
The rubbcr samples (01 and 02 gn1) for the stock solutions are weiOhecl out to an aCClllal) of o~ mg on nn analyti(~al balance The rubber is best mnnipulated by mNlI1S of t1l( stJai~ht hlunt-edged top of It cork knife With a little prnctie( OIl( (an leltlily sepnrate t)w desired portions by pLeSSIl1C from aboye Further subdivision Is mndt on a stout PVllX at(h glnssnt lla~t 2 mill in thlkne~s By pressun f10111 above and sheuling aetlOl1 Ye1~ small pnrbcllH can be separntetl so that the requit((1 11l110unts (un 1)( w(igh((l Ollt accurately The rubber sample is then divided into sl11a11 piC(es on the special watch glass by meanH 01 II coll Imife
One mil1ilit(gtl of lt1i isobutyl ketone 13 js placed in It special 30-m1 trituration beaker (fig ~B) and the fine1y diyilt1ec1lubber sample (01 or 02 gll1) is udd(d and heated on a hot plate under n ventilated hood to Il tempelature jllst under th( boilin~ point of the olvent A special glass rod il used t () t rit II ate the sumple (fig 2 11)
When the rubl)(r hll d issohed so as to makl a hOll1og(J1lOUS geUike 111I1SS hot methyl isohutyl ketone or an oI the other luhb(L solvents recommended (t aIJI( 1) is add(d and niicd with the rubber soltItion
31 Diisoblltyl ketoul WIlS not aailab1p (Juring ValtimC l1Cthyl isolJutylletonC 1II1ly be substitnClt1 11111 it is not a~ Cf1kiCni In Illis olllntion If the IllttC1 is used It is b(SI to pl Ilw fimlr diillPll Iubhpl palll(s slan( oPIuight in Ih( solvCnt lind 10 (OPl til (onlalll1 to IllinilllizC elIpornt(111 of sohPIII bpfolp wa( Is nppliecl to completp nlutioll
bull
bull
bull
bull
bull
bull
RAPID PHOTOMElRIC DElERMINAlIOX OF RUBBER AND RESINS 11
The mixture is tllll1sterled to It 100-ml yolumetlic flask with sevtlul washings of hot solvent cooled to n s(uHluld telllpelatUle and madtmiddot up to volume with the saIne solwlli SlwtiaJ IHl(uutioll mllst be takell in transferring t)( lubbCl solutioll to till YolulIHtrie flask so thnt llO rubber is lost It is cOllytllielit to illSllt It j-ill(h funnel in the ne(k of th(~ voiumptic flask to pOll tll( lubb(ll solut ion ill OIl( OLWlHtion into the tube of tht IUlll1ll with Ihl aid of tIl( glllss Iod nlld 10 follow illlshyl1eilintely with S(gtllnl ~Ynshings of hot S() I(111 whkh lIl lilst pouled 1nto tIll btll PI 1I(ld dIIleUy OW) till 1unn1 aId IhpII t1I1uugh Ill( funnel
H time hi not all objllt it is uls() flasible 10 p1alt Ihp linely diided particles of Iubblt ill tl( flask toJ1tuining Ihl sohPIlI 11(1 allo it 10 stand until til( 1lIbbpI is dissolYld TIl( llIblJll ioluliol)s alp slolpd in Ihe tightly s(ojlP(1(d OIUllwt lit f1nks in a ((lol dark placl Thel they willltIIlUlIl (OlUilallt ill Idut 101 an indlfinit( JlPIiod
Two ellliblHliol1 (IlP~ flIP IIltl(l(-OIl( 101 o~ gill of tisHlIP (ollin illshyhw 0] to 10 PII((Il of rubb(I ((1lt)middot1 to U mg of IlIbb(Iill tt ~)-1Il1 yo1ullll) and th(middot otlHl for ()~ gil) of tisslIp (ollaining 10 10 ~l() peLshycent of lublJPl (O to 10 Illg of lulllJpI ill a ~)-))Jl YOIlII1IP)
(Hns HlJ 111 TO 1 II~IWEX( (II BIIII1EH
III oldl) to ll(llllP (ITOI (0 II Iltinil1lIl1l a lIitahl( lllillobllllltp is lIs((lo Jl((lpn (P IhI ~lt of stal1da Id solut iOlls 0 f a Ii ng (OJllllllllll ious ill til(gt (III)(r( Ol 10 1 gt(I((lIt of LubbI In (11( PI(sPIII WOlk th( 1111shypIoypd HlhlHIg mic)obm(ltp Il bullJ) whkh lIi(IlJalpl dlli(I~ 10 0001 1111 was Toulld sntisiadOlY F(OIll n lll-pltIllllt -talHlulIlllbwl solushytion in HSlIitnbh solnnl lt[lIiIlIUJl1iiat( aliqll()l~or n) Ol o~ n and ()t 1111 al(lllla~UIpd (Jilt ut n stalldUld ~Olllli(lll tlIlIJl(1atulp (~) C ill wlitllmiddots labolulol) I IlIIHIl-of II lllillOillIl(tlt illio ~l-lld yohulI(lie f1nks ploid(d it h gla -(OPIllIS gllollgh of 11ll lubhpl sol Pili i~ thllI addltl to (tl(lt flask to IlIak(1 l 1111 Ill1I IUI(middotc (0 t hl all)ollllt of lllbOPI solutioll ]ll(yiously nd(lpdbullflll DI ntl 01 JlImiddototlmiddottli lolloid solu tillil Iras h(PIl Hddld lIP (bhpl is JlI((i pi III tpd IIlld SP(middot(t )opl)()tolllshyd(gt( 01 (jIOlilllltp) IPallil) an IllHdp 1I((OIdillg to 11ll JlI()(pduJ( Oil shylitwd Oil pagp 1middot1 Th( 1(ldillg~ 101 palmiddotll (OI1((III)Hlioll alp 1I(Iaglt1 anel plotttd Hgaillsl t( ntilligllIlll of 11))1 hI n ~)-1ll1 (jIIlIlH 0) [gt(lClntagl of nlbblI (nltuln(pt 011 tw bnis of tl2-glll lilsul Slllllp1(gts and aliqilOt olulllt IH(IOI 101 (itl ]1I(J((dlll( out lilll(1 Oil pagl 1middot1 This PI()((lhll( i ((l(alld t win ill (a(1 (11( II slandald llIbbllsolushytion was PI(gtllllpd IIOIlI slpa latll XllH(1 ld 1 a utln)(l lllbblI 1 III pips TlwcOlllpl(tpdtlla alp pol(l (1) (loldilla pap(laslrowl1 ill figulp I
Tbl )llO(p(II I ill lllilking a (Uln rOl I to ~ jiI((lIt of JlIlJh(1 i~ simi1t1I to (hat rOl 1Ill l1IlP ImI1 to 1 JllI(PIII (x((pl ill a f(middot dptnils The quinlu]lli(Htl aliqllols a 1( sput(d Ht (lI 12 a j 0 (78 n alld 10 mg ])(gt1 ~i-1Il1 Yolunl III sNuIing thp 01 Illg pll 2)-Jll1 YUlll))lt til( (gtIO(ltlIII( outlillPcl ill IIIl PIp(tding pnltlgllIph is followpd In the rllngl 1 toj Illg )IN ~)-1I11 OtIIl1I Ilw (lsi 1(lt1 (oJ)(tlllltlliollS of lubbpI alP s(gt(ul(gt(l h IlIPHsuljng alhplOi- with Xnlional BIII(atl of Stnndlld~ tltllsf(I pip(Ws flOIl) tltl OI-PlIl(1l1 lII))ll sol III ion
12 TECHNICAL BULLETIN 920 U S DEP1 OIr AGRICULTUHE
RUBBER IN 25-ML VOLUME(MGl
100 1~__middotOT5___ITO___15__2~O=--_bull 2r5_---= bull 3rO__~-_40 bull99
98 shy(I) CI Z
~ 97 ItJ II
~ 96a f-IIJ
e95 o l
94
93
92 ~__~__~__~____L-__~__-L__~L-__~__-L__~
o 1 2 3 4 5 6 7 8 9 10 RUBBER (PERCENT) bull
FIGURE 4-Cnllbrntioll curve for rubber in 02 gill of gt1n~ule tissue containing 01 to 10 p(rcpnt 0 lllbhlI (nlnllillg~ (Ill 1111 J~pl~ll llhooplf(middotttmiddotlc colorimeter with 720middotmu filter und amiddotml uperture the 01 divisions required in actual pracmiddot tice for photometric IclHlings arc olllittltd)
Similarly hl the range 5 to JO mg pel 25-ml Yolume the desired conshycentrations of rnbber urc measured from the O2-pllmiddotcellt solution The complete data lire plotted on semilogtllmiddotithmic pttpel as shown in figure 5 A
STANDARDlZATJON AGAINSL G1IA111 ETlIIU 11 ETHO()
1he alternate ploee(lule of stt121l1ald izing th~ IneHell~ method ngninst the Spellcc-Cald well method (II) altholl~h flaSI hIe 18 not adVIsable because of the extra work J(quiled ancl the introduction of the expershyimental error of the benzene extraction method
HESINS CALlBllATION CUIlVES
The procedure for constructing cal])lation eUlves for resins ttIlulysis is similar to thtni outlinlltl for lubb(l lxcept that resins exndate of gunyule is lIsed as the resins stundard The resinolls exudate disshysolves very readily in the resins solvents listed in table 1 It may be prepared in two ways for use as a stnndard-the clean exudate as bull gathcrcd from the plants is dried for 6110mB nt 65deg C nt a 30-inch ltcuum or the oXllllate is dissolved ill acetone and filtered In drying
bull
bull
bull
RAPID PHOfOMElRIC DJllImlMINAlION OF RUB BEn AND HESINS 13
RUBBER IN 25-MLVOLUME(MG) 2 3 4 5 6 7 8 9 10
r~
eo en ()
90
f--70z Q ~ 60ltl LIJ a ~ a LIJ 40 E 0
0 50
~ 0 ~ I 30 0 ~
A 20 I I
o 25 50 75 100 125 150 175 200 225 250 RU88ER(PERCENT)
RESINS IN 25-MLVOLLIME (MG) 2 3 4 5 6 7 8 9 10
1--90
80
en () 70
I z Q 60ltl LIJ a
50 0
a ~ LIJ 40 E 0 0 ~ I 30 0
B ~I20 o 25 50 75 100 125 150 175 200 225 250
RESINS (PERCENT)
lJIGunE u-Cnlibrutioll cUve for (il) rubhcr in 02 gill of gllnn11c tisme conshytainingl to 2G perc(lt of 11IUU(Il I1na (1]) rpSillS in 02 gill of glI1~l1ll~ tissue (ontnining l to 20 nelecnt oC l(sin8 (U(ndings Oil 1111 E(lI~1I llhotollectlit colorlmeter with 720-mtL filtcr and O-ntJ aperture the lO divisions llquired In uctnul prllctlce for pitotoulPtlie PllllillgS tlre omitted)
in vncuo arelntivply HllHlll qUllntity of (xutlnte is plllcel] in a lalge dish since the mass rOHmS nt the beginning of the drying process Pracshytically ull of the ne(tone is evnpollltpd olf oyer a steam Ol WItter bath and the residue is dli((l pnlYllized in It mortnr and preserved by
14 lECHNLCAL BULLErrN H20 U S DEPl OF AGRICULTURE
drying as indicated for fresh exudate In all ClSeS the products are stored in airtight containers in a dark coul place
The usualllnge of resins from gunyule tissue is about 2 to S percent on a dry-weight basis For work with this plaut therefore on1~ one curve is needed A typiCallesins ealibrntion CUlTe is shown in figure 5B
PnocEDuuE J~OH RUBBER ANALYSIS
Duplicate lXiLllCtiOllS arc made for each tissue analyzed and duplishycate photometric readings are made for each cxtmctioll the final value therefore reportcdreprescnt- nn avcragc based on the four phoshytometric readings
Thoroughly mixed O2-gm samples of the finely ground tissue are weighcd for analysis on the basis of l11oistUlc-frec tissllc The samples arc weighed to an accuracy of 02 mg Oil an analytical balance The method of deriying factors for making eOllections for moisture in samples has been thtailed on page
The weighed samples arc trallsien(c1 to the 2-m1 volumetlic flasks with the aid of l-inch glass funnels and 20 m1 of methyl isobutyl ketone is added to each flask The contents in the Hasks are heated m a constant-temperature oil bath at 115 0 C for 30 minutes uncleI a yentilated hood rhe flasks are removed and any adhering oil on the outside is wiped off with Kleenex 01 H similal cellulose tissue the C011shytents of the flasks am cooled to a standard tempellltule (25 0 in the writers laboratory) in a constant-tempelutllre ater bath provided with a motor stirrer if available and made up to volume with the solvent After the contents are mixed the flasks are allowed to stand for a few minutes until most of the insoluble residue settlcs to the botshytom The extracts are then carefully poured into JO-m1 heavy-duty centrifuge ulJls so as to include as little as possible of the settled insolushyble residue The centrifuge tubes are stoppered with cork stoppers and the liquid is clalifiecl by centrifuging for 10 minutes at 2000 revoshylutions pCI minute The clarified lIquid is poured into 25-m1 volushyl1Ietric flasks plOicled with ground stoppers It i impoJtant to pour off the clalificd (dlart in lWIt a lUlllie that the ill8ol11ble cNi(hwis not Sti1((Z1tp A 1-in(h funllel is plncCd in the neck of the volumetric flask A filter stick (fig 2 D) is inserted in the centrifuge tube through he liquid so that tlH enlnlged palt of the gtiek seals off the insoluble residue and a small portion of the exmet in the cone point 1Vith the index finger the stem of the filtel stick is thell held against the side of the tube towllnl the analyst who holds the tube with the thulllb rmtl t11illt1 fingCl The txtlHct is thell poured off easily into the yohunetlic flask without distnrbing the insoluble residne The COllshytents of the Hasks are then ))ollght to the standard tel11pelatme in the constant-tempentl111e wnter hath
The reagent blank us(d wit h the spectropllOtoll1lter 01 (olorimeter ig prepared as follogtvs ) 1111 of methyl isobutyl ketone 01 other solvent used is pipetted into It 25-m1 yolumetric fiask and 01 ml of protective colloid solution for rubber is added the mixtule is made IIp to olume with acidified Oil-pelcent ethnnol and mixed again the rcquired vo]shylime of the mixture is poured into a cuy(tte or an absorption test tube
From each plir of tissue extractions to 5-1lll aliquots 01 the clarishyfied extlact at the stnndanl tempCraLule ale pipcUed into 2ii-m1 volushy
bull
bull
bull
bull
bull
bull
RAPID P1IOTOMElRIC DETERMINATION Ol~ RUBBEH AND RESINS 15
metric flasks and 01 m1 of protective colloid solution for rubber is added to each One additional5-mL aliquot from each pair of extracshytions is similarly prepared to serve as a key to the standing times for the final readings as indicated in table 2 These additional aliquots are first made up to volume with the precipitant acidified Do-percent ethanol mixed by carefully inverting the flask three or four times] and allowed to stand for 4-minute periods before the reading is made on the colorimeter Vith these preliminary rendings a~ a basis the standing times for final readings are taken from table 2 For example if the colorimeter reading in rubber analysis at 4 minutes is 655 then the standing time is 15 minutes
The two rell1Lining duplicate aliquots for eath extraction are then made up to volume with acidified D5-percent ethanol mixed by careshyfuIly inverting the flask three or four times nnd allowed to stand for the required number of minutes as established by the preliminary 4-minute trial readings (table 2) before the final colorimeter readings are made on the contents of the flasks
TADLE 2-St(llllliIlU time for variolls (OllccntratioIlS Of rubbcr or rcsins aftcl iJleaipitation bcforc colorimetric readings mc macle
[5middotml aliquots of rubber in methyl isobutyl ketone or of rcsill~ in ncetonylncetonemiddotcellosol e 3middoti both made up to a 25middotml volume with pr~cipitantj readings on lvolyn photoGlectric colorimeter with i20middotml (690to iiOmiddotD11) filter and Umiddotml aperture]
RUDDER I
Range of colorimeter Approxima(e S~nuling i Rnnge of colorimeter Approximn(e Standingtrial readings after 4middot range in conmiddot tJIIIG for trini r(adings nfter 4 range in con tifillnlOalcor minute stunding time tcnt In tiSSU(l Unnl I t I t (rending IIlIDU C stum Illg lOW _ tent III Issue reading
Percent Villlits II Perfe~lt Jfinul 955-999 bullbullbull bullbullbullbull 09-01 00 01-03S bullbull ~ _bullbullbullbull_ Jl-O9 10 743-954 bullbullbull ~ bullbullbullbull __ _ 43-10 30 1420-550 bull ~ ~ 137-94 5 6_3_9-_74_2__bullbull_ bullbull bullbullbullbullbullbullbull_-_---- 6__8-_4_4---___ bull ~ ~ bullbull ____ MQrcthan 13ibullbull_-~_ _ ____ 15_~elow t~ 2
RESINS -----------------------------~--------
957-999bullbullbullbull ~ 139-01 60 11419-amp11bullbullbull _bullbullbullbullbull ~~ 13~5-939 10729-956bullbullbullbullbull_ Ii 25-1 middotJO 30 ~gtl2-40(L bullbullbullbullbullbullbullbullbullbullbullbullbull _ 2025-1320 5 595-728~~~ bullbullbullbull 8 as-G 20 20 IBelow 292 bullbullbullbullbullbullbullbull- More thun542-591 _bull ~ bullbullbull_bullbull_bullbullbull 038-039 15 2025 3
I Precipitated with O5middotplrccnt HSO in 05middotpercent ethanol When the npproxilllull concentrntion of rubber or rcsins in solution is not known trinl colorimeter rend
ings atmiddotJ minutes s(nnding till nrc mndelS n guide to the required finnl standing time indicated in the last column III prncticc UII cxtrn nliquot is prcpnred for precipitation and thIs is discarded after the trial reading is mnde
3 lrccipitnicd with OmiddotpcrccntlhSO ill HO
PnOCEDunE I-On UESIliS ANALYSIS
The procedure fol resins unulysis is the same as that indicitted for lubber analysis eomiddot(I]lt that f he -olyent js acetonylacetone-cellosolve ~)-7 tht precipitant js O5-perctnt H~SOI in H 2 0 and 01 1111 of the protective colloid solution for nsins is added to each 25-m1 flask conshytaining the aljquot of the extract before the precipitant is added
PnOlmmlHlC INSlHu~mNTs UECoIUlENDED AND CALCl]IAlION
OF UESurlS
Photometric readings of percentage of light transmittance (T) ale made on the Coltnum double monochromator spectrophotometer at
16 lECHNICAL BULLElIN 920) U S DEPT OF AGHICULlUHE
750-111 wave length or renclings n1( mnde on a colorimeter pLoic1eri with the monochromatic filter eOIl)Il1l1tioJl for sllecting the npploxishymate wfLYe ]cngth at 750 1Il~ For routine deterlllinations the Evelyn photoelectric colorinwt(r ployided with aTW-lllJ filteL is IC(0l1111HIHtll
The liquid in hich the preeipitnted lubber uld rcins are susshypended is pOll(d very cHrdully down the ill~idl of th( clette o absorption tube to lLYoilllllC fOLll1ntioll of ail bllbblls Aft( LUbbet find resins preeipitation wlwn the EnLynpho(otkcllie (olo1imetll is used the readings are nmde nft(L thl standing tillll- hOWll in table~ It has been foulld (OIlllliellt to 11lPtipilatl tublwr 01 llsiIlS from the aliquo(s at ~-millute illtlLvals This allows stlilieipnt tillle to check the eOlolimet(r and to makc 111( lNHlings Vlwll a ehangp is IlltHk fLom onc rending 10 the l1lxt it is advisablp 10 llle the clIvctte 01 absorption tube nt lpast twkp with slllall p(Iltion- of the llllltiol to be leitd
After the colorimd(L lluding lta e becll Iltndp till IlIl II igllIlllS of lubbel or resins or thc lpL(el1hlges pnslnt in Ihe aliqllot are r(u1 from cal ibmti(Hl (urVlS (fig~ 4 and raquo or from plepn Led tables of eqllivallBts baecl ill each (liSP on (x[lerimPlltnl data The results are expressed as percentages of dry weight (S hours drying nt 100deg 0) of the original tissue The errol lltle to lCflyjng the insoluble residtH in tbe voltlllletLie pxtLHclioll flflsk wlwn the pxtrnetis being mnde up to YOlllmC is V(ly slight sinlte only (U gm of tissue is used FOLroutine allalyscs lhis ery slight eLlor mny be dislpgnltec1
EXPERIMENTAL RESULTS
The experilllCnlal reslllts Oil hi(lthp method- of tU)lPI and l(sins analysis a le based ttl( d icussld blicfly hlrehl
PHEPMINrlON OF SAlULES
No difliclllty was expPtitI1(ed in pltparing slmplls of llllrscly-glOrt guayule plants 1pss thnn ~ YPH1S old 101 rllbbpl alld IPSills analysis In the cnl of Odll filld-gl()n gllayull plants PIIOtS hopel mtty be introdmp(l by the custOlllalY Jlwrhod 01 pICpalillg Ihp sampl(s 101
HlutlYHis as is lwipfly i n( ita ttd ill th is s((tion Smh enOlS do llot nffCct the ])lCcisioll O[ t1H llwt hotls for LllbbtL n nd Il~in~ nnn I sis i nee till) are due solely to tIl( tbsup--ampling (llo(pdule in thi (a~e of oldeL field-grown plall TIll 1lllt1lOcl of salllplill7 fipld-gl()l1 plants JllOLC than ~ Y(HrS old thenfort Ieqlliles iurtlHl jnttigntioll
lgtAHnOILr~G FOR HEllOVAL OF UUVLgtS
Parboiling which (onisls in boiling gllltyule plants in water [OJ
8 to 1~ ~ninll(s ~s col1llllonl) uSNl a~ n llHans of Itlli rCnl()y~l prior to drymg nnd gllnllng It I~ tHI([())P ll(e~Sllr to ltItLeLnunc all possiblt~ eflct oi tlti PLOtPlllll( )ll (Il( final results Exp(liments have sh(nm that (helt i- fl Flight loss ill til tmiddotjght of lOO(S and 4(ll1S In I typi(ul lXpelillltll hlu1llHs of ~- ii) -1-ytII-old gllllll( pllllb were Italnd at randolll Olll ( of talns wa- paLllOil((1 and the le~es (1( haIHI-pi(kpd [lom till o( hpJ Ht Both pis (1( dlipd for 48 hOttlS at (i) C in a llI((lwlli(al (011((( ion Oyell Th( lpsult are SUI11111I11izNI itS follows
bull
bull
bull
bull
bull
bull
RAPID PHOTOMETRIC DETERMI~ATIO~ OF IfCBBER A~D HESI~S 17
Dry ucilht lust ill lariOilillf
Plaut (pcrcrllO 1 1 -I2 ___________________ _
213 _____bull _____ bull __ _______ ___ ____________ 12 2(
pound(111_ ______________ 1 R
4_______________ _______________ __ _____
A __ bull __ -_
The efred of parboiling on till final lllalp i SUllllllatmiddoti7(middotd ill figmc G Rubb(1 lecoYelY w(t about 1 percent higher for parigtoillltl plants and lEsills re(ovelY somewhat o-er 1 i)(lr(lllt 10Wlr The (Ii tference in lublH-l r((o-elY cannot be ae(01111tltlt1 fot by loss in dry weight _ due is to be found in a study of thE grinding lwhadol of a parboiled and an unpnrboilEcl shrub The grinding of the patboiled shlub in the hnml111 mill is much fadlitated and ns a rule for tissue with a rubber contCnt below 10 peteent llO aggregates of rubber deelop in the 1Il11ehinr during the (Jpelatioll Yitll the unpnrboilNl shrub some dillictdty may 1)( (lxppliellrl(l Sill(( sOllle of till sti(ky ltxlldutl Oil the plant may scI( u nlldei for the fmllHltioll of lublH1 ngglPgates Til is apparently explnins the npparlllt los in ruhbpl frol1l the llnpariJoiled hrllb as eompnlelt1 with thl palboilld (fig (i) TI1(loss in r(sins
II
RUBBER
10 f-
Ishyz LIJ 0 0 LIJ 0
9 --RUBBER -shy-------shy
-- RES INS -shy---shy-----_
IJ) 8 I--Z IJ)
LIJ 0
0 7 f- RES I NS -0 -shy0 LIJ III III J 6 f shy0
LEAVES REMOVED BY PAFltBOILING
5 f shy -shy - BY HAND PICKING
4 I I I 35 30 25 20
SCREENS (SIZE OF OPENINGS IN MM)
FIGlRE Ii EtIe(t IIf pnlticlp sizE Oil lEcorPQ- of rubber lind (iiil1s when lEgttiye wEre remond hr Pl1liloiling lind h~ hand pi(king ((Dlltrol) plllllt1lt groUlld in t hammer mill
6114038-46-3
18 TECHNICAL BULLETIN 920 U S DEPT OF AGRICULTURE
recowry from pUboil(d shrub may be due to the loss of the resinous exnc1ate during parboiling This exudate forms ns It SClim on top of tlw )iquol in the tank
On the basis of t1wse results the recommendation is made not to yaly the nwthoC of leaf lemoYal in any 011( lNi(lu(h project Then fltirly compalabh IcmLts should he obUiined
70 ~------------------------------------------~ LEAVES REMOVED
BY PAR80lLING ____ BY HAND PICKING
60
-I-Z 1amp1 0 50 a 1amp1 a
en 1amp1 gt1amp1
40en gt-CD Q 1amp1 Z
I shy 1amp1 30 a l shyx C)
1amp1 ~ J 20 I shy 0 I shy
10
O+--L__L-~__L-~~--~~~~~ o 10 20 40 60 80 100
NATIONAL BUREAU OF STANDARDS SIEVES (MESH)
FlGntE T-lJiMlil)utiun of l1Ultkh si~(s of gnll~II( tiSSU( JrIOllll(l in a Ball amp 1ew(1 mill to pass six dllIerNlt S(I(euroII 1(IlYes Iemoved from plants by palmiddot boiling 11(1 hand picking ((olltloll dpfo1iatld plants dried to 1I lUoistufl l0I1t~nt (If 01 to o) 1)(ICl1It ground tiSSlli IbalH1 1() minutes ill II ~i$hel
bull
bull
bull Kahn shuk(f
RAPID PROTOMETRIC DETER~UXATIOX OF RrBBER AXD RESIX-i 19
GHl~DIgtiG
bull Th~ entire pant 01 plant l)iHt a~(gt fl r(ll it pllllIIirU1ry lSillg fur J hours ntGi~ C prIOr tD t 1( plChmll1atmiddot rLlmhll III a II lItmiddot or n Ball amp Jewell mill ~n llltllysis of paldch lzP- nftl~l (oar-( IIindill shows that tlwy ar( about tIlt llllH fOl parbojlP(t awl IJllllluhoileu hrubs I fir 7)
The coalilly gloUllll ample i-- thPll Ildlll forI toUtmiddot at ni C afnr which it ha lllilobtllL(gt output of ~ llllut lII hmiddot- dptPlIIlilwltl by drying submlllpil- at 1110 fot hOtll- TIll 1 IIIIll i lltllt lmiddot0l111d hi a IluninHl mill TIll mo(lel uP(t in thi IIIk i 1I Hu IIIOilll mill as IllUllifill bv Hoss nnt Hartlet ( 1 -[1lt111- with n1ll1l1 pldushyrations ittI lilnbhell b rill HanlIolll V0ll11nHiol1 ElIillllmiddotrill (0 The size lutllihl11 iUlJnole So I ( 111m t ~ II t HUIII Xl) ~ I L~ 111m nnd So 4 lillllU1 11 ttllilhmiddotj 0 r tllP Imiddotlult~ p(lln-It willI t11(e Sll((IIiZtS with )arl)Oiltll awl uil)Jtllboiltd hrlll b lOwl1 in fif1l1fmiddot-- This hows t tnt 1middottttIl ~(I 1 llllll (Up jlllilnl IHlt that
r------~-------r--- ~ --r IHAMMER-MILL SCREEN
O~ NO1
NO2 ---shy U NO 3 ---II
I
bull lL
z
r ------ l 30 ~ gt III
i I Imiddot
i ~ I
I 1 I I
~ 20 I - 1 iii 1[ r 10 ~ ~ ~ I _ ~ I r A bullbull
o bull L-~__~__~~__- ~~ 20 40 60 80 100 40 60 80 100 200
NATIONAL BUREAU OF STANDARDS SIEVES (MESH 1
Yutln I i-tlillltiuli Hf pur id lZt f ~naY1l1 t middotnt r1 lI1 i ~ a hatlltlllI 1IIi11 to 1111 Lx IHtllllH middotIn Lt-anmiddot tIlllunl loy la1 litkh~ omrl t 1) tHul parbuih~ -t B ~ thmiddotfuliufptl ]~lahr thpt tu tt fit t 1 It+gtr-tt1 Jnui~tHn eunttlIt _~rnlitl tl~UP ltakmiddot~~ 10 UddU it~ 1 rtmiddot4~pt~middotK1~r ttakt-middot
bull So 1 gingt- 11 tt-liuin-Iy ltr~pl [lPlItl1tat of iilll 11animiddotImiddot- Eqltrimiddot tIlllll hnnmiddot llOWIl dutr fll llltldllllUU xtlutioH 11pound lnhbll lIl lP-ill frolll IolUlIl ~tlaYlllt tl-IlP by dlt IJwtmiddotlUlmiddot lItlilwd oil Ill 14 - 01
i-mllt 11111- -lwltld hi INd I li~ Ii I TIll lllhtIlttj of Itiu~ So 1 (lltll j thnt 11middotmiddot01middot lttwmiddot to amplil tltt Iollllli tilt art lpdnn ib
IntIIll ll~ i po--ihJI with tI lLllit Ilfltl[lll1t It honld l Plllplw izmiddotl rImt ilt tht h of -allllhmiddot with l lllblPl
~ontlnt of ill PPltllt til lIilll it i tlllt pll--ihl 10 11-middot t(1i Xli L
20 TECHNICAL BULLETIN 920 U S DEPT OF AGRICULlURE
Even with screcn No 2 difficult due to rnbbel tlcrltreCtlltiollS may be ob tl
encountered In thes~ caHeH it iH lWit to parboil the shlub fOL leaf lemonll and finally to dry to about 1 to ~ P(l((llt of tnoiibl1(l pound01 b(~t results jn ~rindillp in tlH hanmHl mill
It iH aclvlsable to provic1l thc hammer mill with a ground wire Hillel the presence of static electric (harges 011 tll(middot partkhH will ealls( Home of these to atlhelc to the inside of tllP (olltailWr OJ lila eallsc OI1l( of till pULticl( to form ngg1(llatls EIIolin lalllpling fl01l1 fhis SOI1I(I mlly be (onsi(h1llbl(middot
A1I10l1g the Holnllts with high boiling point that lIlay Ill IlHld in rubber anal)Hs I1IP Illllhyl n-alllyl ketolle methyl ioblltvl kptOIH diisobutyl (tOIH blltyl tHptate llethyl amyl 1Ittail (middotthyl(middotlllmiddot gly(ol diethvl (middotther and n-bntyl (middotthel (labl( 1) TIHse al( also I(sin 01shy
middotent but th( 1(~illS n1( held ill olution by the rll1)bpl pl(l(ipitant tthanol wll(1 lllbb(r is 1)J(lipitatNI (S(ll tabl(s alldmiddotl) On tIle basishyof the lxpHilllPlltH tll( btsf nil-round lolPlli -rol lS in 111( PIlHPllt method is lt1iisobutyl kPtonc wld(h was not IIltlllllfaltllllmiddotd ltIlling Vodd Yflr n A suitable Sl1lgtstit ute iH llHthyl jolllltyL htolt whi(h is l(porhd as llolltoxit UJ)
Clllos()IY(~ (ethykn( glYlol monopthyl (tIH1) blltyl earlgtitol (di(thyl(ll( gly(ol llIollobutyl (ti1(r)~ and acttonylacetOll( may be used as resins sohrCllts (table ] )
In the earlipr work with (sills analysis cpllosoly( alolle was selcmiddotet(d as a suitable solycnt Aitholllh (ell()~oh( alone is pxc(lllnt its rplllshytiwly gwatlL iscosity 1(I(b to bubbl( formation nft(I (SillS pr((ipi tatioll Thi- increased thp (xperimentnl (LTOI OIl of tltp othll I(sins solpnts tI((tollyla((tolH has the proppry of glpatly lNlulingshydH(OSity 11(11 altld(( 10 othr liquids This sohpnt tlHIeforl wa addp( to ((Uosoh( in slIflici(lJlt tlllIonnl to OPI(0111e the dinieulty On the basis (li~ex)le1inwllts ~ purts oi~ a(donyla((tOlll to I puts of (elloshysoh-f (bolll by olume) as Splldcmiddot(l Thp 01 hel Hoh(nl listed hutyl clLlbitol at l(llst the t((hnieal-g1lld( ploduct uSNl is appal(ntly not as good as eithe of t1w ot1(r two () a (ombinatioll of tlWSt
The SOlVllIts JOI liSt in tumlyzing artifkial lubbel$ hy tlw pr(senf method appllLently (lcllIHl on th(middot kind of llI))(I lIp-ityl (Jxidt is suitable Ol BUlla fi and hutyllthlI for butyllllbbl Tlwse reagents IlLe technical g1lld( Calboll amp CtllUil1t Ch(lllilai (OIP This Hllbjp(( hilS not bepn (XtpllHl(ly illwtigated by till WIit(I
PIIECIIIIJ-
All tlst fOl Ih( adlqlJalY or till IHllipitullb ll(Ollllllentillllll11Sl bl baset] on the plctisioll of tllP final I(snlts oiJtairwd with the methods The )redpittlllts s(1e((( n HpJ (xtcllsi( (xp(IimPlltatioll all HatiH~ factor (Hee fig Hi 111lt1 tabItmiddot (jH) Ext(IIin tllts llllTild Ollt hanmiddot shown that H Hatil-gtflltlOIy [gtIpeipitallt 101 1lIbblI is (li-p(IT(middotnt HzHO (c p reagent nil POll sp gl U-lmiddotJ) ill li-P(l(Put (tinmol by vohmlP liol (tllayul( Ipl-gtinl 1l)-P~ITImiddotllt H)~o ill Hl) by ollln( ii lL satishyfaeto7-y l)lp(ipitunt A solution of 1 palt of H~~o to 1 part of H~() (1-1) iI2So1 nnd abo yarious int(lIlIPdiat( proportions of tlllse suhshystanCPs giyp fait 1(511It8 but with till inlIptl(l ill [h(gt ratio of H~S01
~
bull
bull
bull
bull
bull
RAPID PHOTQlIEfRIC DETEMIlXATIOX OF HtBJER AXD RESIXS 21
to H 20 the )olutioll becollles somewhat vbcou5 and precautioll Il1Ult be taken to ttvoid bubble formation When it i5 poured into tilt Cllvettes
It should be lloted that both of these precipitants have an ftellleshymmiddottion It was found that when XHjOH was used in the rubber preshycipitant in pInt of H~~O~ the readings were -table l)Ut were not reshyproJutihk The lIl of XuOH in pInel of H 2SO j ran nHittble result as a llth H(HY(Pl WIWll til( li-P(l put lthatgtl in lublltl llnalysis or H~O illlP-ius anal)j wn-i uddint(1 thl eharalteliti(s of till liquid with pleeipitated ruhber or resiu in HI~P(ll-ioll n ren1 on the lpNmiddottroshyphotometel m tololinlPtprfollop(1 it lPgnlal lIlll II~ lxplaiHd on pHgP-I (Sl( figs 11 aIlIIl) Tid made it lloible to outain lEPJOshydlHibll tpnlt nntI (onplt1J1(Jttly till JpqnitPIl tlPgJPP of PJPcljoll
IIWIE(TI 1lt COl~101J)
Jtl thp ItJiPl middotxlwlillltnb hefoJ thtmiddot -1l]YIlIt allll pnmiddotdpitallb had lIptll ptoppJly adjutp(l it l fOllll tIuH till llP or a Ploltiw colloid -wll ltIi1)cJ [ttlJmiddotntl- imlIopl tll lmiddotpro]lIibility of the lPlllt JmUkllly ()Ilt 111 U lput lUlU illlihumiddot tOJllPOlUtl tpHd liglyeol teltlut( - llpanlItly IllmiddotlfP(] to lit til I1m t IHflll lImnnmiddott nftlr tlH filial prOIptlllll WtlP dlvPllill1 tlll 11lIlpfit (If thtmiddot [llltlltin lollohl wa Hot 0 natlv I1l(lhmiddotd III rlumiddot Ia- of tmiddot ill tllmiddottJmillaritlu it b [1 hmiddotjlmiddot til IIpoundgt Ir llH1 It liltr ill-llImiddottiT Ina lll ptlPII by it U( in ruhhfl mmly j 11If dtmiddottail fOJ tltt lllllmtlllll If thl plot pet in nlloid ~llntill tltlmiddotlImiddotmiddotlttlatiflll lIOlllllllhtiPI1 are iPllllll page
liTFHFEHliG COIOf
(hi II tht lllail 11111111111 that had til ill -111111 II urklll) om tlH method fot lublJtt tlIlO1 rpir- nlalv~i in plaut llllpll- wa ttl (lilll~ inare tIte (gt1[01 till to tIll ptP-PlHt f xi [aIWIIII- 111 TIlt amount of (olor varip from lUllIt tn -amp ]pplwHlI nlt rhmiddot lt IIf thE Hl(ltllial tllP part of till plllIt -lI11lhmiddot(l tilt hi-tlllY f tlll plaut mtteshyrial ~ub-lltInent to Itlllmiddotnmiddot-rill lliI 1011middotly OrllPI Inlw
In ruhlwr lrtl-i I Iii 1101 au Itmiddot 1Iplll11l by 111[ I--r ratmiddottilt thE -lllll]t with uptoIw or 1middotmiddotlIll-ol - wIdell [llllol- rlll loillriu nutttel autI thtmiddot lpill- Thi- howmiddotvt n(tnll- til lXtla -11gt1 ilt prlJ~edun) In lP-ill ltluay-i nllHufldy tlW[t j 11 1 1IO(PIlln fill the 11shylImya of hlulophyll Hwl rIlI-r middotIOII IHlttlmiddotJ dlH lUtl~ In plltIH withoUt alo aiftIriL till nmiddot ulttrll
111 pllIbIll1l Wi tilmiddotr hId h It-ImiddottHI tht Pltlpll 1 hlitlt lilt tlw tulllWlli tollImiddot uIwltllIIntut -lltUIhorlllllltll 1111 tIll tlettlllliIttwr IIf t 111 lWlrl-Uamiddot of bdt tl11blLlittUhmiddot r [1 tItmiddot preshyj
lipitatifll 1lJ llllllWI atbull 1iI- in III -1nrmiddottIi fHlttalldh nlrillU~ amount rf middotlorilig lIUlttll Iii lhll of ih lltmiddottllllhottohttt~l l~ol()r infrtl Hm II upd 1 rwmiddot tld~middottilmiddottll PlllItlhi~ f it j proYitiltl with tIll lilP--UlY tU(jlIdlllIlml tIltmiddotmiddot lllklllUIlI
EIECTIol OF 1 [EGTH~
-Ptfmiddott ral tracilull ru~lI gtIll fr 1 nllb t ~xtltd 1 lIlt-th vI iobmy1 ketommiddot lWtl rill [ Ixt lttltt ll UttollylaIiIitt1l11I1t~ ~-I itoiu YtHil)u~ typp of ~IHaylllt f i lItmiddot art hraquoil ill fio1ll1 ~l Th~ lp-nlt fill I11oohl uio[1t ttl willlr til tltN- fur rht IUiXtIUt iwliutll
100
22 TECHNICAL BULLErIN 920 U S DEP1
90 bull eo
I shyz 70LLI 0 a LLI a 60
LLI 0 50 z
a ENTIRE 2-MONTH-OLD PLANTS~ 40 b ROOTS AND BRANCHES OF ~ 3-TO 4-YEAR-OLD PLANTSen z WITH LEAVES REMOVED ex 30 a C CURRENT-SEASON GROWTH OF l- )-TO 4-YEAR-OLD PLANTS
20 WITH LEAVES REMOVED
d LEAVES FROM 3-TO 4-VEAR-OLD PLANTS
10 A
0
a Cd 100
b bull
10
80
I-Z 70LLI 0 a LLI 60a
LLI 0 50 z ex I shy 40 ~ en z ltI 30 a I shy
20
10 B
o~__~__~__~~--~--~--~--~----~--~--~ bull350 400 450 500 550 600 650 700 750 BOO 850
WAVE LENGTH lM~)
FJGcm O-Sll((middotlllll tramaniW1IHl (mrpS f(JI (xlmll 11011 n J1ll of jlta)nle tissur ill n 2--m1 Y011111P of (A) Illrthyl ji1I1J1ltsl krtonp 1111(1 (ll) nt(middottQnyla(umiddot tClIc-C(l1osuln a-i
bull
bull
bull
RAPID PHOTOlIElRIC DETEH-UXATroX OF ntBHEIl AXD HEstxs 23
ThE dula Pl(S(l1t(lltl indi(ntp Ihut 101 Illp ulimls llHthyl liohutyl htOlIl (lxtrHts (lI(I r(dolls of Il1Hxi11111III nigtol]gttioll wiH1I all (is-lIb 11 cOllsic1(]((l n1( blhn(11 wn ( ItIl( Its lIO to () I1It~ nlid Ii to Iii mJL
WhllNIS tlw I(gions of 1middottnL(s( light 1lnlllittamp al(l lgtPlW(PIl wan Ipllgtltsnr) to Ii nllt jW) 1I1JL nlld alio Silllill1l 111l1b (n SI(lIlId 101 nc(ton ]altmiddot(fmiddotollp-(llloolp ~ pxt Ill of 11a 1111 t illl TIl( (1101 du( to lolo ill tlw litlltitl a 1Il1 lullll(I tH lPill- hanmiddot bpllI PI(_ ipitated ma he 1((I1((d to fltI ynbhing poillt II ph( illg OJ illshylmiddotJall(( WIWp balld nhm ()) IIIJ1bullbull[1I111 lxjlPIitllll1b Illln -h()1 that Ih( lIIot uilahl( WHYI lHlIJ fOI 1-1 ill 1l11J1l(I HIH11Pill- illllllrsi i-in till IlPighl)()lllll()(l of ~llIl1lt bull
bull UIlIilHlIy of n typhn] lXPllillllllt to )10 l1iP(tiP ((JIlllo( of (ItOIS dul to lOIOl in 1llblnI Hnd Iill xtnumiddott 11(11 IIIIolp t jUl i p1llelll((l ill tub]lL Till llhlllt- 1tpIO]II Hnd ((llll~()h whit-h UI(I ](]Hllilltl n 1I01lllIhb1 01(111 lxt 11111 IIll 1llll)1 nmtp[in I and )(middotills Tid IIlnkl it poiblp nftlI tlIp uplll1tillll or tlll o1PIl( (0 [niH lip 1Iidl1p~ of lI111 11111(( ill lit ll11l1)[1 (llnlIb nlld Ihll
Sl(ll n ol1lliOI with tllP olnl IJllt illiollt HIl Iltlllll llllI (Ill ltllthpl prpipitnnt j Ihll1 nddld OUI ha a lIilPt lP( of till lIiciPlw of WH( lllIgth 7) lUI- ill llilllillatiu (nnl till tll Ixtll1I101l ()lll~
Tuu tmiddot-Elilll IJl flrldillY 11-1111 lrlllI IjfJI til islII 1 1(1 ([rllt IIIIIJIlIr JiIlIt~ if 1Il( Ihll 111111 k til I III Ilrln I 1Intd tf 11111 JiSf fill I I II I tIII Ilf Iilltl 1f1JlIIillII1f I Till 1[ 1 IId 1 (I (middotIt 11111 (I1I1iI1 1lf1IWtlfJlIIllfflr p middottrllhIJ11 II J III 7IImiddotIa 111 111 lilt jJIp 111 wilTII
t~t tnVIli~ ~nn r kn t~ i tmiddot ~~l Jr 1middotmt ltlTt
HmiddotOtt ~I~ lin t I ~ 1 t~~l ~qrmiddotthtmiddotrtwb
Hult-middottltlru t T Hw ullut rHtt~ r II I ~ PH~lllt
A~tmiddottHHjmiddott~rjd rl ~gtllh 1 tn~th~ ~ ~ middotI lt~ b w bull hmiddotth~ 1i~lIhun 1 Ii tnl Illd1 -11lt1(11i lullI lUI tJl ll~ t1~11n( I Ihan1li flfttIJir Ult I Uuhtltt ahuul l(hmiddottHmiddot~t trv r fti HIt lftbyl tlonhUt)1 k_hIl( 2 m~ fmiddotf tuhlHmiddotr In mlth~ llmiddotlf- 1 t r
t r_~ t j
Arhlitlltd ~llIIDHl NcWitn1 ( Ar-(lt()nc~middotttrrtrt ritJJI~ -Iu nllJtl4-middotr
ACtmiddottflnp fmiddotxtrn( ~ T-P511ftf tn mtmiddotth~ 1 ~difmiddotut~ kdn 2 nltt ulruhhtr in Un-tIl lltbu )J~IYt
rUth(Hl~hltlft HhubU
Illlh(I(t tttUtUt hUbtl til J ~jlitl(J Hilllll trtIIImiddotjtl1ll
(UShl I ~tlO wHllolH rulh r (middot1111$0]( J~rru t t )lthyl 15bullbull1middot1101 klll1l
Ili( UHUicbcul ~((i1rUtl ~ulu1iin 1middot lIUIll Ilti lrllltlllt I Ruhhr llt1thuI r1 -1 Irld
ltlt1111Sh 2 nuz f)rruhl~rm nlith~l tu- h f nt nil~middothgt(H] tlrlftmiddot 9lUtirtl middot1 1
rlcltfl( H(l dnllltml it
(IISllhH~rI( Iultruhtr CII05 1v ltTlft I 2 UI~r ublwr In llldh I hlt~1 11) lgtjdvr(llsl~9rlltmiddot middotlmin ~ I~ gt AIHItilltl no IrttipHallr iI
~ Bbnk 10ol m(thyl i~tmiddotut~i kdHn H 1 m1 j~~ l1rH-t lt~tlfltmiddotn sf n it ll HltlMjftr~nol O2~mlJ ~U~1o-ulp ti~tW -xtra~middotl(lt1 ltt 411 ml bull ie f Ct- kft rt t~ tirattJ middott ill r u l1kn ttJt
in metltl isobutyl kNqnf nn~i mljp ur tmiddotmiddot ~oml ~urr tttl i t w ltJj1JH kt 4t 3 nlank 1 mL((l1t~rthmiddot(middot mI mttr~ ~but a kmiddot tmiddotc d 11 ~ gtli~b~ hifIAft- fl~ lL lnti 149
ml8(dlfilll BO bull 02 gm guayule U$Stl(middot xUlClt-l tf(h tft wI n nmiddotmiddotmiddotlgt 1 lznt on tmiddot ~Jt r~1 ~~u~~ H~ iI~ thT
24 l$CHNlQAL BULLETlN l20l S DJltJPT OF AGHl(CLlOHJltJ
In table a is pl(sentc(l such c1il((t edlt1tIHC showing that thc (0101 Ixtrnetccl from guaYIIle tisslIe wit h II(P(OIl( n nd (pl1oso[yc is cll(div(ly sCIe(nec1 out by the s(lp(tion or wnw length )0 miL Oil t1w SI)((IOshyphotonwtpl This tnb]p all-HI ihos thai thl Juhlwl altl(l((1 (nn IJl quall shytitntivcly 1(I(()(Ipltl in tIlt PI(ilIH( or Ih (o]OIplnwPIials and Illsins and tlmt Iuhb(l WtlS nppnlllltly 1I0t (xtltI(((1 110111 11l glll1I1l lisslIt b~ tlHSP SOhlllts Thls( ((suIts ginmiddot (OliIHillg (idJt(( that t Iw IISI of waYl llngth i)ll 1Il) OIl till SppdTophot OIllltPI ii t hl 1101(1 p(oshy(ellule in photolllliTie IlIlalysis of luhhlI OJ l(sin-
SELEGTIO- OF )IOiOCUHO)IAIIC ItIIm ((1111110
On th( basis of th( IPHIlb shoWIl in tabl(l 1 al hlllpls (1( IIln(lp to SPCtl lC the PIO]Wl 11101lO(lIOl1ln til Ii ltlJ ((lIllIJi nIl ions 10 llIiOlS (oIOlimet(Is 111(gt 7W-Ill~ filtpl flllnhwd 101 til( I1~lI1l photoshyplpct1i( (o]oriJl1ltll fol which Ill( (hlll(IlIiitit~ oj t hl Ilda he light ilUIlBlIIhiSioll (t) elll nn -hO11 ill fig1lle 10 iws satlsfa(lolY IPshysultl 111( iiO-mL HitlI olllhintioll 101 whkh ttp (middotIatinmiddot light tlnnsmission (ullmiddotis a 1-0 showlI ill figllll (I is -nthdnlto1 hut this is not stnlHlnld NtllipmPlli
Up to fhl PlPHllt lIS(middotflll pound11((1 (ulllbinntions jn lltl iOO-I11L Iunge hayc nol bllll SlClIlld 101 lhp Klpt 1-1I1l1I11PISOIl (olOlinwtll bu fnltlwl nttCl1lpti 1( )(illg IlIHd
TJIpound OF ST~lmW AFTEH HIIJ1EII Oil HHSIS rlll~CIIITTI(J
~ considl1ltiol1 of ttp lillll of Inlllling af((1 plpeipital ion of 111gt)(1
01 l(sinSTlOIll ollltionis impoltant J(jl~ thC1HI(Plltngp of light IInIlSshy
11 rshy10 f shy
09 f shy ~750 Mil- DOMINANTI
~ 08 cshy I WAVE LENGTH z
I III III i O7 - I III
~06 - 05 shyw
a
Igti= 04 - 720 Mp DOMINANT ct WAVE LENGTH- ~ 03shy
02 f shy
01 t shy 1)O~~~gt~- J 600 700 800 900
WAVE LENGTH (Mp
bull
bull
bullFIGlRt IO- COJllPIUlItiw ~IW(middottltll tlnIlRlllii-lion (II (IllP( 101 1i11(1 olllhinulloll
with dominllnl Il(lllllgths at 720 and 7iO lUi
bull
bull
bull
HAPlD PHQTQlfE1IUC JjETER~lINATION OF Rnmrm AND HEtiINi 25
mitted (spertrophotoll1eleL lCuding-) Ol light (1 (tClcrl (phOlOshyJluol01l1et(L lcndillg~) i~ StlhjNl to (hangl
]fjt~l1le 11 and l~ show that ill til( (asc ot tJaugtIllitteltllight llJHC th~ (x[llliHlllIlnl (oIHlitiOllS tllpl j lilst n dtlln-e ill Pll~(lltngl or UllllslllittnlH( follrnY(l by It ptJiml of lClntin stability with only sliuht (1111 tHn- a f(Pl a lIt1ll1btJ of minutes The light t UIllllitblllll t l(1 ill(Iln~(s This lIIay IJP llllllJltlli7P(ll1 ffl II ow 1Ilt )( f(( darI oliIII tIIlIlNlIlitt(IIIlfJIIlh (iditilIiid Ilil1 pllIipintnl )uoshyIn Of ( 8inx in (~f1( I~iUII i~ Ild stahl I 11 itlll If 1inl nh prlshyilli(ioll of 11l1d(1 II IJIX f) jllIli II (fJJltfiIIlilty slllMI IIriot 1) IIIPldUnl1i tll(I1I rllltltilJl oj tJi~ Jlt jiot IUN ilUf Jxl1 will tIt( tOWI IItlllilil I 1llIlllblJIol I ill I~11l11111 d ill till ifjuids JjOI scnttplltl light 011 till phololltHJIOIl1lttl till dilPCt ion 01 elangl b tlw IPrfIi (If that illrli(atPll rOl tlulll1Jittp(lliuht It Itlll b( llluliJr I-(Pll that if l(middotndlnJ- IIIP mad n itl I t lIP ~()ll1d()lb lpalll this pllioJ of nmiddotlatirp tuigtility tllP llLot tIOllt thi Olll(P (nil bl IPdUCld to tIl lltini III 11 Ill TIll l~adiltg (illH~ bbll Oil tlHl datn rUl lublwls and llsinlt Illl ginll ill tnhh
50 r----------------------------------------------- f shyZ
~ 40 ~----~W~A~V~E~LE~N~G~T~H~7~5~0~M~P~~~~ ~ --------------------=-=-= ~ 30 f- WAVE LENGTH 540 M~ _z _____ ___ -=- __ _ ~ ------shyt ~_=---=-=--I GUAYULEIII 20 -Z HEVEA ltt II KOK-SAGHYZ f shy
4 6 8 10 12 14 (6 18 20 22 24 26 28 30 STANDING TIME (MINUTES)
FIlirtn 11 Emmiddot of wav hll~rh Il li~ltr tlall~lIIit1alHl aftI IUIlItHt -Imlli lug 111m for guaynh llmiddotn 011111 middotiolIlJh~z 1111111 llijlitul1 flolll 1lHlh~ll1Jllryl k11II11l ~(lilltlll h~ lwitlitll 111Inu1 111l~1It1 2)1111 o1U11111 (Helillins on (illllun tlunhll IlIIJlllw]ntllW111 lutl(I[lholtllllltlt with ijUjt Wlnl IHI Ilf1 I
11 EFFEGT OF Hbli 1 -()JXT10~
Tilt lnblwl ~()h(llh pxtnl( till IPillgt ubo It 1m nllu1- bellt -~atea thut ~lll 11-111- tUP olnbhmiddot ill middottIIlIlOl ~1It tlWIIJI( my U)t PIl (tlIHatcl WIth tl1l lullh(t I tahle lJ 1hln 1- -1111 tIll (llllstlOll of nny p()~iblt tITptt of XtIIl11 diflp]lws ill ((JlllPllttUliollS of 1l-in lil lolutioll alollJ with till 1lIltbpl TIU data ill wbh +ho on tIl( hn~is of (olorilllPill ladillU thaI tll( IIUOIl1t of lnbbll Plllipirntld 110111 Ilwthyl olnlld kptOlll olntioll IJ 1li-jHlllnt 1l)04 in 1-llltlIllt ethallol)- not amlll hy thl llllNlI(l of llvin aU1ouut of llins inolution bull
-----
26 rECHNICAL BULLEfiN 920 U S DEPl OF AGRICULlUHE
100
90
80(I) C)
z Ci 70 UI a 0 60 a ~ UI ~ 500 ~ 0 I Il 40
30
A 20
0
100
90
(I) 80 C)
z Ci 70 UI a 0
60a ~ UI E 0 50 ~ 0 I Il
4-0
30
B 20
0
--
--shy ---shy---
2 4 6 6 10 12 14 16
---shy= ~ ~ shy
-
2
025 05
10
15
20
25 -30
35 40
SO
-60
=70 80
16 20 2224 26 26 30
OS
- 10
IS
20
2S
30
35 40
-50
-60 -70 -80
bull MGPE 25-ML
VOLUME
bull
MGPER 25-ML VOLUME
Florm 12-EtTld (If till1l or Slllldill~ 011 light transmittallce (01 (A) gUllyulc lnUIl(I plccipitllitd frOIll llltt h~l isobutyl Ielollt solution Ily neidilic(l ethanul bull null (B) gUllyule ll~illii pre(ipitated flom aeltoll~lllcetOlll-Cl])osolY( 3-7 solushy11011 by H(illilip(i l1U (HPlldillg~ nt -lIlillult Ifllpluls 011 Evelyn photoelectric colorimellr with jU-lllp tlllll alit U-1I11 npN(lle spp also table 2)
bull
bull
RAPID PI-IOlOMEllUC DElEnMINAlION OF RUBBER AND RESINS 27
TADIbullbull ] 4-ReZation of amiddotmount of middottbber pleeipitate(Z Oln metltlIL isobutyl ketone 80lutions by OS-pereent H 2SO in 95-pere(lIIt ethanol to umollnt of resin8 udde(l U8 indivute(Z by colorimetrio readinU8
(Rubber ami resins cnlculntcd on bnsis of amounts in 5middotml ullquuts of extract from 02 gm of tissue in a 2fllll olumo( bull
Hubucl r~cocrell whcll rcsins nddcd as IndIcated Htbbor al1dcd (pllcollt) ---shy
__________bull_________ ~_12rpcrc~15011crccllt 7511crccnt IOOpcrcent
PerCtllt ercellt Percellt Percellt Percent o o o o o) 50 250 263 252 25000 500 500 500 500 700 750 750 751 749
1200 1250 1250 1250 1250
EXTRACTION TEMPEHATURE AND TIME
Typical experiments to detllmine the time required to secure maxishymum extmction of rubber und ltsills at 115deg U Ilre sUlIlmarized in figule 13 the solvents used-methyl isobutyl ketone for rubber anrl Ilcetonylacetone-cellosolve 3-7 for resins extraction-are very eflicicnt since under the conditions indicttted maximum values were secured after 30 minutes of ext1llction The most eflicient liquid for the bath (lig 1) used in extrtlcting rubber or resins is ~ high-grade cylinder oil (S A E ~O) The sand bath and such liquids as glycerol have proved unsatisfactory
RUBBER AND RESINS STANDARDS
According to the National BULeau of Standards 1-_ lhclc Is no gellcrnlly recoglllz(d standard lIIutcrlul [ior II rubber standard] The rubber hydroCllrbon ill llifferent samples of conmlcrciul smoked sheet or pale crepe from heclI pluntlltions nries from l~ 10 04 llercent of the totul nutletmiddot the most 11Ioruble conditions Of preparation
McPherson () has described a procedure for the pLeparation of pure heve~ (Hevea brasiliensis (H B K) MueH Arg) rubber from crude rubber or latex In the absence howevcr of ~ generally recogshyn12ed stalldard for rubber hydlQcllrbon [caoutchouc (CnHUs) xJ the standard adopted was that of the relnthely pure product secured from gunyule tissue txtractiotl nccording to the Spence-CaldweU method (5) or the motlified PIOCCdUlU of Hohnes lind Haasis (p 2) The details for constructing the calibration CULes are given on page 10 Standard rubber samples apparenl-]y can be stored for a long timc under the conditions des(libed on page 10 The duplicate colorimetric lendings for glULyule rubber newly extracted by the modified SpenceshyCaldwell method were ()J2 ench as compared with US) each for the sample extracted by the same method but stored 1 years In each case colorimeter rcadinllS were made on mixtures containing 2 mg of rubber in It 25-1111 Yolume
The selection of tt suitable standurd for guayule resins presents some dilliculties Tll(~ acetone extract of gUllyult estimated on (l gravishymetric busis~ for instance proved to be variable depending on the type of tissue sampled or season of sumpling because such fractions as
COllllllunlcntion dul(lt1 Octohtr 22 11H3
28 QECHNICAL BULLEQIN 920 U S DEPT OF AGRICTTIIlURE
16~==========================115 shy
14 bulli= 13 z ~ 12
ffi II Q
10 c w 9a w
8gto () 7w a
6a w
5en III ) 4 a
3
2
A 00 5 10 20 30 60 90
14~------------------------------------------- bull13
i= 12 z w II ()
a 10 w Q
9 c w 8 a w 7gt o () 6 w a 5 If)
z 4 If)
w 3 a
2
o+B~~__~__~____________~__________~ 5 10 20 30 60 90
HEATING TIME (111 NUTES)
lllGUltE 13-lDffect of time o( lICntillg O2-gm samples of gunynle tissue with solYlIt nt llfio C on lo(OVl)ry of lllhlJer alld 1Isim Lt HlIhblL extracted with methyl isohntyllwtone B resins Cxtll1cted with aCftonyla(etonc-cellosolve 3-7 bull
chlorophyll are weighed along with the resins in the acetone extruct but are not estimated by the present photometric method (fig 0) 1he use of a diffeJent stanclttrd waS therefore indicated
bull
bull
bull
RAPID PHOTOMETRIC DETERMINATION OF HUBBIm AND HESINS 29
The resins standard selected is based on n relatively pure source of resins the rcsinous exudnte 011 the stems of guuyule plants IJldimishynary expeliments with the resi nouS cxuclate from diffcrellt gllayu Ie strains of various ages indicatc nHlt there is little YaLiation in this subshystance on the basis of Colorimct(r readings 011 2-mg aliqllots of 01shypercent solution in It 2i-ml volume (tabl( li) Expelilll(lnts have shown that the air-dried (xuclate contains 3RtOH p(Ic(nt of -volatile matter This material is l(latiyt~ly stablp ill (OlllpoBition and is npshypurpntly on ly slight ly hygroBcopic as shoWIl ill Ia bl(1 1 Tlrp Ipsinolls exudate may be jJleplpd in two wayi-i fl liSP as a stallClHld-(l) the clpan exudate is clripd iol Ghouls at ()1deg C at W indlPs of a(lIum Hnd aftclbCinOglOund ill a molfalis 1)I(spI((I intn airtight COllilinel OL
(2) tllP Cx7lclate is clissolllt1 ill a(lhllll and filtplpd PlactieaJlyall of the acetm1l is thpn lYapolntwl olt OPI a stlam or atCt hath and Ow residue is dripd ground an(( PI(sPIld as ill tllp fin lllethocl Tlwse two prepalHtlolls a1( (ompalpd in ta hlp ) 111( (((tails fOl ~t()lil1g the resins standald and (onstlllcting the calibration CUITPS alc given Oil page ]2
lAIIIg fi-CUIIIllrsoi (lJ lIr-dr(1I IIIIi 1((11 II II-()I-tr((l l(sil~ 11111111(8 of I II 1111Ie
[Colorimetric rrndill~s 011 1~I11 phulll(Iclrie eolorillJct[lr with i~()middotmll (100- to iiOIIIIl) fillcr [lnd 5-1111 lIperture preeipitantl part ofO5middotPIrctllt 10 to 5 paris of IIOj
nupliclllc(oloritwt([
nIl(lin~s (hIlSlcAg~ ofSlmillXo JrNliltlCllt of fPsiJI$ L1Xtlrlntp on 2 IIIg ofplanls fllsins (XIHIIlt~Jwr 25-1111 vol
tII1(1) 1
leflTs Various _ bull ____ bullbullbullbull 3-9 Colll)Josiltrlairmiddotltlricfl bullbullbull nf)2 002
])0____ bullbullbull _bull __ _ bullbull ~-l Composilld (ri d at n5 C in aUmiddotimh lWUUllJ for l (jOuj(ja hours])0______ bullbullbull __ bull ___ bull 3-0 COJIlpositld disso]NI in neptolll f1l1erNl fl(lf()ll( GGO i(jO (Ivaporntld olT OV(1r Stpl1l11 halh TesidlH drl(ld I1t fi5deg ( ill anmiddotinch VIl(Unlll for 0 houlS bull
middot106 __ bullbull _ Jir~c1rild_~_~_ _~_ ~_~ _ ~ ____ _ __ _ OUu GOifina_~ ~ _ ~~_~ ___ _ _fln~ ~~ ~ ___ ~ __ 6(imiddotI tiliA H)[_ ltlu bullbull i18 tisSflOabullbullbullbull__ bullbullbullbullbullbullbullbull lt10bullbullbull _ tillO llitO406__ bullbull __ bullbull __ bull __ __ lt10_ Utl2 fon591_ fo__ bull liGa oOa 406bullbull _ __ lt10bullbullbull_ li5S OM
j Ph( vnluls in Uw Inst COIUIIlIl indieatp thnt gunyulp fesinous (IIHlnt( wlwtlwr dfircl hi Yn(tlLJ1l1 wilh L~ perc(nt loss of volntllt wutl pr or tWl c1rild giVPd npproxil1lnh1ly t Iw snllw colorinwtCr rNHiing- 011 till busis of aliquot~ cOlllniuiug 2 IJI~ of flsillS lXIHlntp l)tIf 25-mI volultl( Ihil- illdicate~ thl11 Uw UITW IJ1flS~ of olnshytile mntl(f prt~(iJlitnt(d gins npproxilllntlly Uw $1II1l (oiOfirnl1tlf ftudiTlJs ns tho ftsidtw A pnlill1jllaf~middot (XIlltrinllnt indicutls thlli th VUllltill muller l(lIlSists of thl Ilrplne oil fmcl ion I5-(1Il gtnplls or rlsitlOtlS (lxudntll gnvll by stPll1U distillation nn Uefllgl of 011111 of jl(lfPlIW oil with npproximHte tilllsity (If OHIi lind lhus rrprlsll1ll( IlPIJroximllt(I~ 01 Jerccllt Of t he original weight 1hls lllrClnlage complrcs wllh 38 llltrC(ntlost by drvinI( in IICllnllJ
aSplusmnUH perceilt or orlginlll weightlosl
The wailnble illfolJllntioll on tlH (ow-JitlPllts of the gunYllle r(~shyillOllS exudate alld tl1( HeetOlIP ext act of gaylp ti~slw is sllIllmarized in this paragraph lYalttI (u) alld also Hangcn-Slllit lind his coworkshyers 16 reported that 20 percent of the resinolls exudate from gUltyulc stems is parthenyl cinnamaie (CHuOH=CHC020 11JI2r) Steam disshy
15 (OIlIJIIIIUicatioll flom A T Haai(II~l11it llId (0011(11 Calif0111 ill Tnfiitnte of Tccllllology Past(IlIJI Jhps( wOlken al Htud~ing the COTlHlitlllllts of the acetone extract and other conlltituellis of guuyule
30 TECHNICAL BULLETIN 920 U S DEPT OF AGRICULTURE
tillation of similar resinous exudate in the writers laborntory has yielded approximately 4 percent of the whole as the telmiddotpene oir fracshytion Haagen-Smit and his eoorktrs nportec1 thttt about 25 percent of the acetone extract from guayule branches is parthenyl cinnamate and 6 percent of the bark (ltortpamp-phlotm) extraet is parthenyl cinshynamate These workers fm-thcI reported that 25 lwletnt of the nc(shytone extract frolll bLllllches is a compound with the tlI1pilicaL formula CBoH400a 1 percent is a compound llwltillg at 2P to 2T5deg C and 1 percent of the extract from the ]eav(s is tl (olllpoulld nwlting at 100
to 1710 1Valtei (6) reported that 3 to -l perc(nt of the tI(eton( txtract
of leaves and flowering StPIllS of guayulc eonsists of waxlike substances soluble in olgallic soln~nts but insoluble in at(l and (on(ent1llted H 2S04 The flactions mentioned on the basis of (onHLTutle esti shymates of amoullts actually isolated tlecoullted for about H ptIcent of the totalncetollt~ so]ubles extracttd from tll( guuYllle 11 rub The other constituents ltlilaill to be i(](ntifi(d
RUBBER AND RESINS CALIBHATION CVHES
Typical culibndioll Clllves iol Iuhbpl and I(sins bas(d 011 (ldtLminttshytions made nccoLdillg to the plocCdmC outlin(d 011 pages middotb to 1G arc shown in figulPS 5 and 1+ The spCdlopliotoll1lttL en (OIOIjlllctCI readings are plottCd on s(lIlilogalitllllliC pappi ag-ail1st (Il 11IbblI (011shy
100 ~ 90
80 ~ 70 ~
z 1amp1 0 II 1amp1 IL
1amp1 0 Z
60
50
40 ~ltI 30 ~ en z ~ ltI II ~ 20 C) ~ oJ
10 o 2 3 4 5 6 7 8 9 10
RU8BER IN 25-ML VOLUME (MG)
bull
bull
bull FI(lURE 14--Ctlihration curve fotmiddot gllftYlIlc lubb01 (Hct(lings Oil COIPIIHlII tlOl1hl(
monochromator SlCClrophotolllet(r with 7fiO-11IL Illtel alld Hllp Wll ( IHlll()
bull
bull
bull
RAPID PHOTOMETRIC DETE~MINATION OF RUBBER AND RESINS 3]
centrations From a casual inspection of these CUlTes it would appeltr that Beers law does not hold Actual tests indicitted that Beers law was applicable only within a narrow range in the upper portion of the curves The analyticlil results on the basis of photornetric readings nre therefore calculated by direct reference to calibration curves or from reference tables of equivalent values bllscd on the cnlibllltion curves
Calibration curves for kok-saghyz alld heyea lI11tulltl rubbers and Buna S (GR-S Chem Gum IV Goodyear) and butyl (GR-I Standshyard Oil Co Protoc) sYJlthetic rubbers are hOWllil1 figure 15 The samples of kok-saghyz rubber were furnished by the Diyision of Rubshy
100
90 ~I) ()
z 0
1amp1 a
~ a
80
70
60
s 1amp1 ~ ~ 0 ~ KOj-SAGHYZ 0 l Il
50
HEVEA~ ~
40
100
90
~ 0 80z Q 70a Co)
a 60 ~ 0 0 x 50Il
40 ~----~~----~------~------~------~--~ o 2 3 4 5
RUBBER IN 25-ML VOLUME(MG)
FmUIlE 15-CaJiblation curves fOl kok-snghyz h(YCII Bunn S lind butyl rubb~ls (Readings on gy((yn photoelectric colorimeter with i20-lIIp filtpl and 6-ml aperture)
32 TECHNICAl BUIJLETIN [)20) 1 S DEP1 OF AGrnCUIlfURE
Iwt Plant JIl(I~t ignlioll of thi BlII(un and (1( l))(parcd according to 11( SPltI1((-Culd (]] (6) PIO(((lllll Hlpt pal( CLPPe was (xtmch(L with acetone blI()Ieit W 1I(gt(11l a ttnlldal(l
SEXSlllVllY Ol~ llETJIonS
By lip pIO((l(II11P olltlillP(l 011 ]Hlg( +n Iowa (lOOl IIIg (11 1111i(l0shygmm (gHlllllla) of 1hblI ill a 2)1111 yoltll1ll (all )(gt dltpltld Oil tltl Col(man (lohlP mOIlWhlOl1lHlOl l-I)((t 101 l1lOt 0111 ci( I ill1ilnlly 001 mg of Iublwr ill a 2J-1ll1 n]ulllP Illay bl Ilad Oil till EnI)1I photoshyllectlie (O]oLillllt(I Thll ya lllll- 011 tilt IHl-i- (J I (xl ad iOI1 fmlll 02 gill of til-lI tH(JI(lillg to tllP -lllndal(l jll()(pdull 1(PIPStlIt IlO()2J tlnd 002) P(IT(lIt of llIbl1ll IPI)(((inly bull1t1lollgh -lI1t low allils can be d((d(middot(1 il lIoullt1 Ill IPtllizpd thnt till PIIOl ill PlI(Plltng( or tll( al110unt dltlIllIilll(J i ltlatlpl high ill tili PIY lo Itlllgl 111 aetllllllladie(middot Ill( lopl lillliL 111)(1(1 lIw (ollllil ions of tlil ]lI()(lltlIIIl u ol1tlinpd ipt at l11 11I1 or 1111gt11(1 illt i-1ll1 Ollllll IlPIPltPlltillg 01 p(gtl(pnt of JllUiJtL un tlll 1Hli or (xlla ion rlOI11 II rlll of tisSIll
EIlIlOH COSIIlIHIIO
In Oldpl to H(IIp ill )1lHtPltt pl((iioll illlpIi1I- it i lH((SSHI to slnlldHIdiz(i rigidly 111( Pl()((dlll( 0 illdi(ntpd Oil pnglt- - to J( If lids i dOlH tlip lXIHlinwnlal PIIll is t(middotdllld 10 n ndninlllill
Illlt pl(iioll of (hI ]lIPPllt 1IHllwd Oil til basi of ]llllP llIllJt1 alld Ipsinssollltions call hI jlldgl(J 110111 figllll Hi lileh lio- til HPIlIgl d(intioll oft -illgIP lI1lnSIlIlIIIlnt in lHi((lltagl of Ill( alllOllllt 01 Illhshy1)() 01 lpsins d((PI1I1 iJlld TIl( (1101 PlI(Plltaglt H1( gi (1 101 OJ) to
RUBBER IN 25-ML VOLUMEMG) 004 01 02 03 04
i= I I IZCtOW
fbA ICtU CtCt WW a
01 02 03 04 05 06 07 08 09 100 = RUBBER (PERCENT)
RUBBER IN 25-ML VOLUME (MG) 10 20 30
~ I CtZ
bBOw Ctu CtCt Ww o I~
010 50 100 150 200 250 RUBBER (PERCENT)
RESINS IN 25-ML VOLUME(MG) 10__ __3-0_ 40 50 60 70 60 90 100--_-- 2_-0
Ct~ -r- 1 I OZ
WCt UCt b C wCtW
a o I I 150 250
RESINS (PERCENT) o 10 50 100 200
bllI 1tI W-Yllnl dtd1 ioll I I 11l1 11IlI11 1(111(11 1 III Plll- IlIIIlol1 01 IIim~
bull
bull
bull solution Il basis J o golH of tiSSII (JlILCl-nt (11(11) for (~I) (l)1 til O 1I1
of luhllpl lin 1 III I (I Ill of lUhlJPl nllll laquo I J to 111 nlg of IlSlllgt (Itllillgs on ]iYllyu pllolwh-llrk CO[IJlilll(-(PI with nOHIP Iiltlr lIntl U-lIll allcrture)
RAPID PHOTOlJElRIC DELEHlllNAllON Cn HUBBER AND H1~SINS 33
10 mg of rubber anel1 to 10 mg of resins in a gJ-m1 yolumC For
bull
bull
bull
comparative ptuposes the leslllts arc also calculated on the basis oJvershycentage rubber OL tltsills in 02 gllI of tissul As WOlllL be expcet(d the error increases sOIlHgthlf for 1(lali nmiddotly low COlHell t1llf iOlls oj rllbbeL or resins The curves in figure 1(j s1l0 that ill til(gt Illlge Ol to 10 pCrshyeent of lubber the elTOI rangts Jroll1 abollt Ll to II) ]IlC(lIt abo(~ this mlllc tIlt (ITOl d(((ts(s to (ollsidlItbly ltmiddotss (han 1 1lICPllt of tlH mllollnt ltl((Lmill(d Hil1lilally in tlH (lISl of l(sins analysis (fig 10) the ltLTor is (onsit1eIubly INS than 1 PlLllnt ill (he lallgp of 11 t~) ~() penPII t
In nil ([lSl of lllhblI alld (sins lx(Inltpd tIOIl1 (issups Ol addcltl to tisslle lxtlads (s(( tabhmiddots (i H) illyolillg ll01P o(lllntiolls the eLI01
is hig]wl thun that indilHtld in figllll ((j Im pUIl Ill )])p I tllllllsins solutlOII
COlllUCIIOXFOH IXSOLl-IlLl~ Ilgsqgt(Jg
111 th( Jllo(pdulP ollllillPd 011 paw I till illsolllhll isSII Ipidll( tflpl (xttlw(ioll is (Ptill tlw lIask l(lll till xtlct i l1wdp up to yoltlllH It is not rOllPllipnt (0 IPt()PI qWlIltitati(Ir III(lw[olH a 11(1 pllooll extlnlfs of guuyull I is-lll alll thl1l main t11l111 up (0 YOIUllllmiddot bpCaUHI sllch all additiollal stltp wottld]) tillll-C(JllS11ll1illg Th( Iogiea nll(gtIshynntin is to mnkp tltl lXtlUCt Llld Ipsidup lip to OllillH in till original flask andi llPSStllY 10 llwlno tl OIIpdioll wlHIl (allIlnting [hc llshy
Hults f(JI [hl oll111lC displupd hy till ins()lllbh llsidll( III it l)picat (IXpednHllt (ollsisting of Jhp lppJiea(iolls if was Iollnd llftt at ~iiO ( 02 gill 01 Iuhhll pillS IPill-fl(( lisslI(gt (lollpdll fot llwistUlC ou basis of dlyillp ut lOW 101 ) llOlll-j (lbp(ld only t~ llllUll voiul11P of OOk7D~- OO(lOO(i Ill of lllthyl bolnl(yl 1lIOll( (lplhlli(al-t(Tnltle sp gl () Ii I ll(Hli (j at ~)) -gtitllP tl1(gt 1It101111( () r t is-lIl xt Iadld j sl1lall til( PlIOI dul to Ill(gt insoll1blp Ip~idll is slllall III [0111 ill( wOtk it (all lJp diIpgal(ll(l
]hcon~lIY OF HllIllgl AiO HESIS AIH)gl) TO EXTlIACI OP
GlYlLE TISSlg
Tnl)ll G L(IHpslntillp (ypi(nl llld(~ SllOS (hat all a plngl of HIOK PlI((nt ot lltl pltl( Ilhl)(l acldpd to tllP Itll h iolJut1 InmiddottcJllP xhnet
of guayulp tiSI1( WllS 1l((PllIl Tlli nllintioll flOlll (olllplpU I((OYshy
PIY i within flll pxp(IiIlHuttllIIOI ~illli]llly fnbll Ii llows thn 1111 llYlIUgl of 1O(1~ ])(I(Pllt of gllllYllII 1(-i1l- add(d to II( (pllosol( (xshytrae of IUllY]l t i~HI Is 1l(oPIPI
THl~ (~ Hf (Off Ill of 1111)( J OJ I~il~ lItfI(( In ~(JI1IJk~ Ilf (111 [lI1Il fI2 lIII
0 tlUfllllit i~~I1
Instrument
---- ----~---- bull shy 1(1
Colemun ruono~ltrOUlllt()r 2t) II sJl~ctroJlhOL()lIIeter with 2tJ I iflllllI wnclength Fetting 21 II nntl 0-1111 WU HI hUJl(L _ L U
Ill 7Evolyn photo~lcclrie (olor JU [ imctcr with iO-llIl filler IV (I
H1 0 t I I
llImiddot lUn WII 1011 HIO Wn mil lUulon
10 JIg1111 IUI ml lUl anh Io aLn 111)_I ) III li lU It 2) deg wn2SU DD
Irl JIll II IIr II US II
1110(1 lULa lUI IlK) IJ WU
I( llI Htl tNI 1(111 2tlNI HI 0 221) lllil t2S 0 1~ 10 1~13
In (I 2117 I
10U 1l(J ~ 4 _H_j ___
9middotJIlJ5 10115 10 00 lUU5 flUU 4li (tl03 9(11)
leIlKl 1l~)5 lOOU l1KIr JOIS un 003 OIl Ii
34 lECHNlCAL BULLErIN 920 U S DEPT OF AGRICULlURE
COMPARISON OF PHOTOMETRIC A1D MODJIoIED SPENCE-CALDWfLL METHODS OF RUBBER ANALYSIS
Guayule samples were analyzed by the photQ111etIic method and by bull the modified Spenc(gt-Cnldwell mcthod The values in table 7 represhyselltativ(I of typical results indieate It -atisfactory dcglpe of conformshyjty between the two methods in thl range of tiSSlHH with llHHC than OJ) percent of rubbtImiddot On the bnsis of the amounts determimd the results in this runge for the plmiddotts(nt lIlcthod ayernge apploxinHltely j percent highcr
~LAIII~ 7-(oIllJl(i~on of lltlllrIic (IIri mOtllinl SJl(II(r-(ulri-wall IIIrtlwrl~ of rlrrlIIillillfl 11)1)(1 COIIrll of UI(III
1 Flowers frllm amiddotmonth-oltl nursery plants
YAIIIATJO- OF SIli(LE DETEnt1NATIONS Fnoll TnEIIllIEAN
Rllbbel (Uall8i8-Thc plcCision of thc pLcsent method when gunyule tissues Hr( nnnlyz((1 for rubber may be j udg(d flom I Ill datil presentcd in table H TIl(se dahl -how that thl pplCPlltag( uriation of single determinatiom from nwan yullles with low standllrd enolS ranges from less than 1 to 4 p(gtrlent
R(8in~ wWlsi-r-s lndi(a((1 011 page ~j he INntlts s((uled hy the present phoolllttric nsins llHt hod are not tliltly (olllpalable with those of the grtLVimetri( ncetol1l-cxtlt1(tioll II1etho(l Thjs made it necesSllry to selc(t another lalibllltion staudud-tlll Ipsinous exullate from gullyule shrub-thut gies relatively COllstlllt photometric readshyings (table 5) The resin (olltents of guayule roots branchcs or leavcs usually ran(~e from about) to 1-1middot pelcellt The ple(ision of the present methotf WhCll gUHyule thslllS lIe analyzed for reins may be judged from the datalHmiddotpscllted ill table 9 1h(se data show that the p(lcelltage variatiun of sillgle lhmiddott(Lminntions iLO11 meun ynlnes with low standard NTOrs rangcs from about 05 to 4 percent
bull
bull
bull
bull
bull
RAPID PHOTOMETHIC DElEruIINAlION OJ RUBBEH AND HESINS 35
IAIILE 8-luriation inclieute rubller (mallSM of [1wIIle tissue bll thc 1111O0Illclc metwII
Vnrlntlon~Ilbher I (rom mean
ierCtnl Percelll ~OU -22 ~ 25 +27 ~ 20 +18 ~UO -22---------1_______ 51110 0G6 bullbullbullbullbullbull _bullbull
10 ro ----=ii41075 -01 1000 +11 1010 +13
rlln HI itil 1l9~ 1_ ___ =-~~~
115511 ~ US -111 III II 1575 -13 115 b tiS -I a 111 h WlU +22IIM-(middot bull 11K -1Ja Illi c 1000 +03 1J5H1 W +l)7 ll1imiddot tl 1575 -13
Mcnn 15951 131
1102-11 21fJ() +21l102-h _ ~~)SO -17 1102-c bullbull 21CO +21n02middotd ~OIiO -26
2 r~plusmn Il~ 21151 261 I -~-------bull---__ _~~_~______l-___--_
1 lhe$ 1111($ I1n (or SlIlIIllltS Stpnnltplr PHrilClld IIrtlrdlng 10 1hr prollIlIlr( OIiIIiIl(o(I on Imgt$ 4 to IC ~tcond nUlI1 hlr r(J)[ltnts stl1ndnnl llrrot of tilt 1I1(1111
1_1l1~ n-J(lri(iot in relli(Upound rpoundsins (lllalIsfs of VIOJII( lixsue b1 the lhomillric lII(lloli
-- ---~--- - __-------- shybull I I I I Varlgttton
_________~___ ~~lu_n_Jl_Q_~~~_____ ______I__~_o~S_J frOID lDean
Percent Percentgt458-1 ~65 +41IWtl-li 130 -a2Hli8c aliO +26S41i8-d bull 130 -32
1(-011 34I10Olifgt __ bullbull __ ~--====
li-9~2n 881) -06 li-9~2-b Si5 o ~HH2middot(middot S i5 -6$-H2middotd 000 +1
8851 054
O i5 +6 9 i5 +6 950 -20 U75 +6
H-liG3o-n bull -1 n-li6~b bull __ _ -IH-IWH +4H-l61511 bull -1
1tmiddottlU
62~-lI __ 62~-b ij24-( bull OH-Ji
(-Ull
I rll(St oluls nre tor separately ~xlrflCled SllllllllCS IlctOrdlug lO procedure outllned ou pages 4 to 10 i Secoud number r~prtgeulS stulldMd error of lIe menn
36 TECHNICAL BULLETIN 920 t ~ DEPT OF A(]RICCLTCRE
ReUUER A~ALYSrS I~ CRCOE-RcuUER PROOCCTS
Sew rapid photometric m(lthod~fol the ddellllinttion of rubber and reii Hi ill uaYllp ti--ut htp lllell pIPHnl pd oil pag( ~l to In A brief H1111111tlY of It similar rnpid llHthod fm 1I1hb~rllnltlysis of u1lulcanizNl tlIldp lubbll pl(Hlmtlt whielt i~ bn-(tldo on the prill o
ciples dehtilcd tlllLe follows Duplltate nt-gm sllmph of the finely cliyiliNl IlInttlitiup wlirllll out [~ei-()l (all hl lIf((tinmiddotjv INd to lt1iyidl till alllpl) TIll kltolll-olubll portion of till )111(11( tlrc di-olved a- indh-Htpd fot thmiddot lllnkill~ of -tlllHlunlluhhll olutiou Oil Pt 1II hut tIl IUlIp Hn lIn l-fplImiddotd 10 lHI-ml rolllllltti( fln-k antil1ltld(lup to Olllll1l The bnlulUp or till JllO(ldllll i- thatutlilllll on paWs -1- 1 IHI Ii 111( 1(111 1- nIP IXPIP--pd nil til IHi or Iw oligiJla w(lullt of I Ill (I11l1p-I1l11Ilt1 1)(0(11(1
Hupitl PlllimiPJojgtiWllllllllh llIltllOd~ fOJ Ihl llPtlmiddotminntion of ImiddotUlJbll tlnd 1(-illo- ill -111111 Illllph of gutlYllll tiUl IIll dl-eli)ed 111() IlltlY d~o Ill nltlI1lld fOl III Iwl Illhlwl- and l~iJlmiddotb(lLiJlg plant TIllt l[Olllhup hns nlo b(l1l ntuptpl fot IIH lltlIll1illtltioll of lllhbpl ill 11lHhrublwl Pl(Jdlld~ HIIl 1111 hI ndaptld JoJ IIll ann lysis of ynt1J(gt( ic lllbbl[- The llllthmb HIP 1gtn(11 fill tIll fol1owill plimiph- III Grinding
tIll PIOPlly driPl t i~lIl 01 Ul tillg tIll pnHhHt to tll l((lllilllllh~lel of filWlH-- til plllllit qIHlIllilnth( lXIIHtioll 01 IIlbhlI 01 1(--IJl- () llsing oXWllutld olnuh (kttoJls IIt(talp and() fllltil for LIbbel and IH(ltIlIlyptIJllIllIoolYlnJld-o flJllh 101 niJlsl with t(lathelr high IlPililig points 111 to n C) l]olle or in mixt tIll thllt Pll mit tlll rnphllxututioll of luhll(l OJ [middot(ill ill ~() to (l mi1lutp It r(latiwly high 1lllIllllltlltP Ill to 1~11 ) l) lllllipitntillu till luhblI OL Imiddot(ill frolll aliquot () f till oltn ion I IlIlllI-i () f Hlltabhmiddot pl(~(i]litallt (willifhmiddotd lthmwl fOl IIlhlHI Hild llitlifild lllr fOJ JP-illl t~) IIlHkillphotollllliilPIIIIiIlof PlllPlltal of liht tLaIlS mittUl(P lIftlI IlIlbll (II Il in PIlipitalioll 11 II WI( Iplllh thnt (limiJlall till PIIOl dill 10 xtralllOlh (0101 (till dptl1minntinll Iph jill 011 tIll dtwlopllIlJIl of H HIli rOI1ll tlllbidity 111 hpl than I (olot rI
jJlIlpOP-ofallnlyi-I ( p(lllil1thb IIllijOI1ll turbidity or 1llt[lIinmiddotd d(ltl of jgtIp(ii(JlI l)~ lIltlkillU tIl plllltollllmiddottri( ntdillU al tandinu tiJlH~ (dlllilll wlli(h IhlllH(lill-- IP 1llutinmiddotly tnhll) t1ll1t an hlsl~1 oil the (oJlItlIlllItion of IIlhlHI Ill I(ill (lIPIipitat((L
TIll -I(p ill till jll()(Plhul HIP 1-- follOylt (1) 1l~UIIL uJ1lplls of thwl UJfJlllHl (II tliddl(l HUt dlipd 11Illtplial an lXIllltel with11 Ill of till nlnll ill t (oU tlllltIPlll[gtPImiddotatlup oil Iath at 11 Cbull fol 11 minutl I) iIP1lIin(middot(lohd til( (XUtllhllll Jltldl lip to It middotml ynlmlll til( (nlifild by (Illlifllgiuu HlId thlPl IlI nliql1ot of tIl (IalioPlllxUlltl nll Uillltlmiddotll(t to l-llll OIlIIlIllril fiuk- (1) For a trial Ilnditlg 0111 III tlll j liJmiddot~t IllHII IIjI to Ohlllll with lilt Pll shy(ilitnnl a 1(11 it 111 (Dod fill llli lIut ( ptotoJIIltlil IPtlllillg-- of pllllntnl or liuht tlUtllIlillal(I oil n (lpel OphotnJlllllI at rase hng-tlt (If 11 llJ Ill Ol It lollllil1lPtImiddott lloyidld with tIll P10]11 I 1110110shy
Ihlolllltt hmiddot Ii1llI Olllhi lIatioll for -1IpItillg UJlproXilll1l tply Wtl P ]Plwth )0 mp are HHlltk TIll Illldillg lliJtaillld fol tIlt 4-milutl tliall(~ll-
bull
bull
bull
RAPID PHOTO~IETRIC DETERIINATIOX OF R(BBER AXD RESINS 37
ing are referred to a table of equhmiddottllut~ previously p1(pa1elt1 on the
bull basis of 4-minute reac1inJ~ for tilE nmge of lot1telltlatiol1- of rubber or resins to bE elHOlll1t(led tmd gidn thtmiddot -tnnlillfr tillIP fill rUbbEt or resins aiter prE(ipitlltiol1 lwfolE photoIllNliI j(tltlill1 un IUade The r(middotnmining dllplllatt aliquot lll then HHllil up te ol1l1Jle and lpoundadillg ale marle ut the -tandillfr tiUlE iudklltll ill rhl tall1lmiddot for the final r(adillg~ -1) 111( milli1lnm or p(tCPlltllt- of lllhbpL (II 1(-in pr(s(nt are rpadholU a prlpan(l table of lquiltlput for tlll photoshymetric readings h1~l(l ill pnell e1-E on pxpPlilmlItal lhln 1111(1 u-ing as stimtlltlds pure luhbll in 1l1bbtl milllYb aIHI guaYllh ll-ill- lxIHlatt~ in resins detNIl1111lttion I
LlTERATlRE CLTED
(1) lUnSbull 1fl36 THE mURMIXTIOS IIF IOTA RE I III OOl THER llT~II
F1 bullrol IlY U(T1l0fll UfSlfi ~rrnrl r flm lt1 KEYS TI Bill Chern 114 44J-l59 illns
t1 ~ICPHHlObullbull T 1J3bull~ lUTHOO roa THE PtRInCAnu Or a(lIUl IRrIlHU It of TIn
PLRIHEU Htllllflt [ i Bill lallllall 111 Rmiddot 711middotj iIlus
I ) RHBERG P B Ul5 A METHIlO Or ~u(ronrll-nl Hi tIII rUIl[1 f71 ii illlI
bull 14 Hoss W flbull and HARDESTY J O
llH IR1ltDII Of HfITilIZfmiddotR DllIJS ltt 1 Yl fll Off gI bern JIIIlI i ~middotmiddotlf IIl
101 SPEltCE D nnd CuoWELr ~I L 1933 DETER~n-ATIOo OF RtBBER Ii nrllllpoundRBfR Iusr 1uI II1 amI
Em~ifl cttIliIa~~ r Ell i 71middot7i l11 (HI WALTER E D
1U44 ISO~nlS OF PRTlltSrr 1trHpoundV bull l UI n W lHHt (Tnmiddot 1ETS FROM GiYI l~iIl lItr Clttrn SII J UI titJ middotn9--C1 ilIu
17 J YOEbullbullr H lO~( roLORIlETRT 771 IPmiddot nl -W Yurk f H Plrwptric hmica
naly-II rimttry lUll XphHHlnmiddot~ y 1 1
11
HI) ~ fPHELolzTRf 57 111bull Lin xw Yk t H lt PhmeHt CblUlmiddot ila AnaiY~l~-(H lithrry and XIhmiddotILpfIY Y wirh enomiddot rrJlllrjr hy H KtlJnJU11 I
t~1I --- and ~ARVER L 1f41 nlua-w ~in L liLhr IS IP ll~ XIW Yrk
bull For-sale by th~ ~a~fr1nt~nf1ent Dt~c~~ogtnts-~ s t1i rArnn~ut Pn~~~ tJffieshy
Washington 5 D C bull Pl lU ~nts
2 TECHNICAL BULLElIN 920 U S DEP~ OF AGRICULTURE
to have rapid methods for the determination of rubbel and resinsl r as well as the already available llLpid analy6cal procedures for the
other plant constituents In this bulletin aee described new rapid photometric methods for the analysis of Tubber and resins in small samples of guayule and of rubber in tissues of other plants and in crudeshy bull rubber products
The classical method of Spence alld Caldwell (5) 4 is cOJ11monly used for the determination of rubbll Ilnd resins in plant tissuC Duplicate 5-gm samples iue used Vater solubles lIl( fiest lel1lOVld by boiling in I-percent sulfuric acid for a hours the extLart is tlHn tlItuen(gt(l for 3 hours and leached fo1 1 houls Ill( slI11ples HI( l1(xt (xtladed in It Teflux-type apparatus wi th HCCtOl1t for]2 hour~ to obtai n the acetolH extract finally they arB extradNl ~il h JeIlZlIe ill the sllmc type of apparatus for at least Hi houls AJtelii 1111 oi l Ol-pClcent solutton of dimethyl-p-phenylenec1iamine has 1lll1l added to the benzene exshytract the benzene is (Jvaporitld and the lublJC1 is weighed
Employees of the Intercontinental Rubbrr Co fi and of the Eastern Research Laboratory Bureau of AgliClIltlIlHl and Industrial Chemshyish and Holmes and Haais 7 lmyr uHrdmodific(l ~pence-Calc1well procedures Acc~rding to the Holmes-Haasis modification wl1ich is used in cershy
tain comparisons (1isCussNl in I-his bulletin thC size of the sample is reduced to 3 to 4 gm water solublcs are extractrd by 2-percent (inshystead of I-percent) sulfuriC teid for Ph hours (instCud of 3) the subshysequent autochvin~ is for 112 hours (i mttalt1 of 3) and the leaching for 1 hour (instead of 3) Samples [lee twn (xtractp(l for R hOllrs (inshystead of 12) with acetone in a rpftnx-tYLJC apparatus to obtain the Hceshy bulltone extract they are finally cxtraetplt in the san1( type of apparatus for 16 hours middotith bCllZ(ne AftCr 1 1111 of a Oo-pcrcCnt solution of p~lellyl-a-naphthylall1ine (instead of ) 1111 of a Ol-pclcent solution of chmethyl-p-phenylenediamine) has b((1 added to the b(ll1Zene extract the benzene is eyaporated und the IIlbber wi~hed This modified Spence-Caldwell method if referred to in thC comparisons with the present mettocU
bull The term reinH as used hpl(in r(Cel tn tIl( lwJion of the l1(et-one 0) Ilcetonyl acetone-cellosoYe 3-7 extTnrt of glll1Yl11e tiue tha I-is pr(ci]litatNl by O5-percent H2S0 in H 20 This preeipitate reprei(nls n mixture 0[ gt(Y(Ia subslanclS An inventory of whnt is kIlOIlIli)ollt IIli fmerioll if gh(n (Ill IlllgC 21 Frolll n physishyological stllll(l(1oinl this fllletion is cougtidN((l at (1refent 11 IIIl IIp(11oximnte measshyure cf the contents of the relill cannl and nny relill that mar be irw]uded in the cells The wo)(1 rCsins without (]uotflfion mark i~ 1Is((1 ill tllP t(xt in this sense
Hfllic nUlllh(I~ ill (1IlI(lltlWlClt 1C(ll to Litllnture (itld p3 bull InfOllIlation in the f1(l of th( flIlina (lhi8ion I11tll(011tln(111111 nllhlle Co
now thC property of till l K DlPIl Iment (If grienltulp bull ANALYTICAl S~CTIOX ]~AIImN RI~TOXI LAllOlkTonY Inonnllus FOR rlI~
ANALYSIS OF lIUT1IJER-m1lTNG r~TS 10 THEIR OERTETlIROIIU(1S [Unpublished] T HOL)[ES R L lind HALSIS F T NOTES 0 rlIE SIENCE-CL)WElL )[ETHOD 01
RUBBER ANATYSIS But Plaut Indus SOils i1nd Agl Engin ~1Xlt Guuyule Res Ploj Rpt [Ullpllb1ishe(11
bull Credit is clue R L Holll1PS Fr HtI~ilt lllHi theil assitnnts ill the ubber laboratory Special Guarulp ResetuCh PlOjPCt Sul I111 S Calif fOl making the bull rubber lind resins detelminu lions hr th( Illo(lifieltl Spen((middotCuldwlll method for use in the comparisons recorded
3
bull
bull
bull
RAPID PHOTOMETRIC DETERiHNArIOX OF RCBBER AND RESINS
Cox 9 proposed a turbidimetric method for rubber ana lysis AcshycordinO to this l)rocedure 5 Om of ground material is extlflcted with 100 mtof benzene for 15 mil~ltes in ri lVaring ble11(le1 or with comtant sha~ing the sltperllatant liquid is clarifieltl ~Y cent~ipoundllp-inJ~ and is maUe up to a lOU-lUI volume The rubber In i)-Ill alIquots ]s preCIpshyitated by the addition of 1 m1 of carbon tetrachloride plus ~o m1 of acetone Rubberis determined turbidimetrieaHv on aliqnots of the extract in a Fishpoundr 155-volt a c model elertlopliotomEtEL fitted with a 52) 13 reE11 filttLmiddot T011pound an(llildlllan10 pLopoeltl a 1l1OdifieLl form of the Cox method O3-gm saInpl(s of the groun(l material are extraettd oWllliht ith 11l Ill of b(I1ZellP the extrHt j (~larified bv centrifl1ing alle dEcn n tNl into a )-l1 1 youl11et ri( tlac awl tlie rEsicluE i Extractp(l thrN a1ltiitiollal time with )-1l1Ipmtions of benzene in each cas( eentriinp-inp- al1d (((calltill) of thl liquid which is added to the oriinal lxtlnet follow ftPL the lxtlnet is made up to a 15-m1 volun1e ~-Ill1 aliquot tlLl piPNtPltl into) Ill of aeetone in test-tube cuvett(s till leultillg lubhl1 ~ll-pPlbion i III ixP(l 111(1 the amount of lubbpr is (lltellllined J tll IPHIiI1 of cnttereclliht Oll n Coleman pleetronh pitotoll1orometer
The aboYpound-l1lelltioIlPd II()(Eltlllrp~ for Lubbpl nIlflly-is W(LP tet((l in the writers lahoratol hut (lid not gin prp(ip alll acculatp llsnts nppalently bp(auie of tlll natulp of tIl( rubhpl ohEllts nn(l precipshyitant used thpoundgt ClIOI cHup(lln (xtralle()lI~ eolor in tIlt Extract and the failure to contto) llflir-iClltl~middot the (hnnrl ill tlIP pilotolUCtlie 1etlllshyinS of lllbhfl in (olloi(lal solutioll Oil talHlill
ppalently 110 photomltlie IlIPth()rl fOL jeill analy-i- in plant tissue hns been reported
The presCl1t photolllPtli( lllPthod fc)J ann Iyi of rlthhlr and resins are based on the folloillf pLineiplf III (~lilH1ill tIl( properly ddecl tisslle to the rpoundgtltuile(l (1(1(( of fhHIHS to pelmit flnantitatiw extraction of rubber or 1(in f11 l1~ill o)-YlwltE(l ~()lVPllt with relatively hip-h boilinf points (115 to 230I C J al011p orin mixture that permit thr rlpld Ixtlactioll of 1llhber or [pil1 in 2fl to ~(l minutes at relatiwy hirh telHppratHlt 11j to 110 0 I (31 precipshyitating the rubbEl or [eill front ali(luot of tht olutioll- by mean of suitable rrecipitant I-ll making photOUlPtlic lpadil1gs of pershy(enta~e of light ttnnslllittarHe afteL rubhel OL resin pretipitation at 11 wave lenp-th that eliminate tht (ImI dlle to extLalJPOll (oloL (the determinatioJl relyinp- on the (lEnlopment of t uniforlll turbi(lity (1 ppl-() miller than a color for pllrpos(s of amtLY-l J I) e(uriLl this uLlifoLm tlll)idity 01 reqnill(l clerEe ()pound plp(i-lm by makin the photometric rEac1ings at stamlinf rlm( I har arl hald on the (oiweLlshytlation of rubber 01 l(in preeipiratetl ThE rrlatiou of COIwentmshytion ~)f nlecipitat~ltl rllh~pl Ot Ieins to -tnhiliry of photOlllEtrir leltclshymp-s Io dtnloped III tlptatl Oil pn14 to 11)
In rubber tlnalyis the u~e of the (lxYrfnntEll lhpnt wirh hili(L boiJing point~ eliminlltP rill II( of thr hirb1y n)latilr and toxie lWllshy
bull (ox L C A TIRBIOt(ETRfC l(~rHI)O fnR THE ~-lY5r 1F 11-1 )[ATFRULS FOR RDJIlER Rubtwr REftT( (OlTl Rpt rCnpllbllhlL 1
Jo~ES E bull T nnd YILD)L~ R G JLPID SE)([~rrlRo ~(~TlIOD FOR THE A~_Lshyysrs OFROIDER n PL-iT lUTERrU Bur Planr Inrlufbull ~oih and Agr Eogin Dibull Rubber Plant Invesr Rpt rtnpllblishErl J
4 TECHNICAL BULLETIN )20 U S DEPl Olr AGRICUlllURE
zene The solvent 11ethy1 isobutyl ketone on wl1iel~ most of the experllnental wod WJth the lubb(r ll1(tlwd Ii bas(d lH reported as nomiddotntoxic (9)
In phsiological experiments tll( alllount of nilable 1l1aietial is often vely low and lubbel ])(ll((ntats J)(low 1 PlI(Cnt- atl lIot uncomshymon Henep the 1(((1 fol Illllltl)tis lqually He(Ulntl JOt nil rnng(s of Lubber contents and rcql1iling tt 111inill1ll111 of plant lllai(lrialis emiddoti(lent It- j5 b(Iic(d that tIl( Illtmiddothods dtgt-(liiJld Oil pn(s middotl to 10 mept these specjficati(l1s In tHhlitlOll the IJl(JtClt111I(S dlS(Libcd t1wle aLC relashytively rflpid
Although these J1wthods welt ltlPlloped primneily fOI llse in rosea1eh on glHl~rule pJ~ysi()loy Ih(y hmiddot( widI ~ppli(nti()I~ riley han b(en uld til lOlltllH 1Jtul( llIlgtbpI alit l(SIIlS tlnalslgt HI an eqnal basi with the 1H0difi~lt1 SpeJlCl-Cnld(lIlllcthod in the gCIlPrul rubber labomtory Special Guayuil Rpsearclt Project since August 1043 They should alo he of ntllll in dptllIIIinin lllbbel lllldlcsins in guaYlll( bre(dillg mn(Nial aIHl iJl ollicl it ud its foJ wh iell plnnt lllatllial is lit II it((l
ROCEDUHES
PnEIAIIATION OF SAMPLES
The details of prepalation of tll( tissllc ~ulllplc are hpt (onslant tluouhollt any 1) rtiellla I I(s(allh Ploj((t Vhl11 portiolls of the same samplps are tnlwll foJ eh(mienl al1alJses h(sic1cs Il1blgtlI anc1lesins the plnnt parts alc dJi(ld ithollt PI(tlpatmlnt Yhlthpr Slpalflte mmples arc talnl1 for the otlwl analyses 01 tllP iolp pl1lpose i obtninshyi ng an estimate of the totrtllllbbel and Iesi ns tlw pIa nls Ol plnnt pnrts arp pa((d in hoiling ralpl fo f minlltps (paJJoiIN])l1 and uny lCfiyes slill adhering to tIl( SIPIlIS alc 1llTlowd hv ta pping on a table top
The plnnts 01 plant pUltS nlp sllbslqucntly coarsely ground in a Viley or otillI suitablp mill and drip to pc1(Cnt or iPssmoisture in a IllcChnnieal ltomNtion onn at (joj C l)(OIp thp final grinding A drying period of nt least 2-1 IlOu1s is IPqu iLN Ill( dried tissue is then grollnd in a ltnml11t1 mill (n llntil it pasls throllgh It 2- or 25shy111m SC]pe1 Th( mill is prodded with a ground win to Iemove stalic elpctricity fronl til slmpl BltWll1l snmplpsit is (]ennNl thoroughly by blowing with eompllsHd niL The ground samplps are tOl((l in ahtight contaimIs Viele-mouth
bottles Hh metnl 01 plastic SClPW tops are 1I0sI COlwcn ilnl for this purpose
8i11(( the J(lsnltsin mot physio]ogi(1I1 PXIlltlinPllfs nre Ixplessed 011 the basis of tllP d I wpight of hI otigi nil I Sit 1I1pJt (II)(d to (onsiant weight at 100 C it is ltifirable to (SPIPS thl finnl IlIbhCt awl 1(ins contents on tlw sn Illl basis A (OlIP( iOll fad Ol i- t h(J(fote d(I(Ishymi1Nl Oil the (inply glOlll1(l 1lotol1ghly mispel sample bY dtying snlnll rluplieate SllbSHlllphs t 1 to 2 gnl) 101 R houts at IO(Fin In ordinary
U rhp plncO( of Pl Iboiling- g-narllllt 1111111 fOI IPIJ1f1yn I of 1(1Y was dyploppd h (mplop of th IntfI(ul1titwlltai Rllhllpl ro CL r (lI(III ]Jxj1lillHntmiddot ~-24) ~PJlt 15 1928) lind nlo IlJlPlirc1 by otlWl flJIployp(s ill Intpl YlI1l~s rhis was nS(PItaiJ1(1(1 from til( fi)(~ oC Ill IntllOIltilllllal HnbbPJ (0 now fill 1110))shyclty of till U S DppuLtIncnt of Agrlcl1itULe
bull
bull
bull
bull
bull
bull
RAPID PHOlOMErRIC DETERlrINATION or RGBBER AND RESIN) 5
drying oyen hen the samples are yery snlall minimum umounts at tissue in wry small weighing bottles t35 CIll high and 22 em in diameter) are usee to (Ol1SNTe ti-ue The sumples pound01 analysis are then w(iglwd Ollt Oil tlil llalis of (onsl Ltlt dry weight at 1000 by using the factor fol 1l10isttllC COIlP(fion
lJAGE~TS FOH RtBBEH AlALYSIS
In a l111lllbpl of eases in tllis -(cti(Jll nnd the Olle on Heagents fotmiddot HesinLllltlvsi It(llllilttl-gltlde dlllllieal whielt were the best obtainshyabll during tIl Wlll])(gtlio(L fLtP indklttd These proed adequate but wllln b(itleL glatils HIe inailahle tIll) (HII he cl1(gt(ke(l to dcleLlnine lny adntntugts of lIbsl ituting p gllltlps rill nbbpl and rtsins soh-enls HIC kept ill glas--ioPPlllll bot Lt
Sollenl~-Methyljs()lJlItyl kl~t(JII(gt t(hnicalgrllll lIbOIl amp Cmbide Chemshylenls COlp is (nUlply latiII(tOIY fol 1I1ltuIHI 11IblJl1 lt is IPportell us appalshylutlr Ilontoxie UI) Although it has thp (IHIIl(fplJ it IWOIll ollor this is leSS IllOIlOUIl(ld than that of othlr IHIOIHs ((Ilsfnuls fol this lIud other rubbel -lIlrellts art given in tuble 1
lAlllE l-Propumiddotfirlr of Hfulr drubIeI olld I(~ills SOllCllts completely soIlvie in 9JpccI)Jt cUtawt
olu billt r (reshyHnilmiddot lation to weight mg ~yenI~NI~ I at (J0 C)point ~1hSolvent FOrl1uh (Ill llOlnl (IIlII(l
lUIIl ruhber 01middot Wut~r llg nlI in lusomiddot
wlter vent
Hubber sohcut c c Benzene l _ elf ~nl ILU olulole ~[NhYI iobutyl k CHltlH(JIC(J(H II 23V do
tonl LNbyllHlfllyl ketOlw (If c1I3IUIllUmiddotoCli lW r 4S U _ do 43 1 1 Diiohtllyl kNone ICH([JemiddotJjlWmiddotU(ll(I1 11 fln 010 06 45 Butyl nCltllt~ (I1roeJ(I1 12fi3 a7~ do fiS 12 ~Iethyl amyl atNnW (ljCO(j(lH1 (Jl(J1lIJ 1 IIi 3 131 lt10 13 1lS Ethylene ~IH-oI dimiddot CjlJO( HtI1O(fh _ 121 I 3J () 110 210 3
rtllyl Nlllr ~middothutyl (ther (ThO Ih 112 37 ~ tlo 03 19
Rcsins oh-cuIsACNone I _ clI C()( If I -~middotI lrNiuhll I()() 100 cetonylnclonp Cn (middoto(JJcHlt()(I WI I ~H tlu UKI llJO EthylD( glycol mollmiddot CHUCUCII0H 13[1 rl2 _10 1(10 100
oNhyl Nher (((lIoshyFohc)
Diethylene gly(ul 3u 7 1111 ~flo lOU 100 mOllohutyl Nlltr Ibmyl carbitol
I fncllulbullbull j lor rOllp3rison lnly
RIlJJIIJ1J( (illituliIlQ SOIIIUJII Oi-I)PtcPIlI n~() (c ll rellg(nt Ill Pont SP gr L~H) oluUolI ill JJ-ptrtPlI( p[buJo Ily ulullIe iR upd as a lUlJbel Illpd) tall r
lrue(it-c Colloid SrltlioJ for RIlJIII A middottipcImiddotPllt iulutillu of diglycol stellshyInte S Or glycu~ttlill a retllJld g)1I11 ur tlid)(middotul nlmt Hot llYailllbe (luring the war pellod) (bUIll tlellnj(IIImiddotIndt Ulycu Prot ItI (middotu- I i IIllHlt ill lIl0lj)homiddot lille (lecbniC(ll-glu(p EusnHllll I TIll slJ(k ur digl)( [ptrlltp ~ ued ill these expfliruellts on till bUSh of tim (htPlmiulltiom nt iJ C IYIIS illO(i 1-ereClt solub( in lll()rptvlilH) rlJe diglyt1 f(Ulute 8 i blOght U(II lllutiOIl by heating tll( oluuolt is made up 10 olmn I t a tandarll tllllf)(rtltUle (25middot
J Z30 King ltrcet Brooklyn N Y
6 TECHNICAL BULLETIN 920 r S DEP1 O~ AGIUCULTUHE
in the Writl Inborntory) al1l1 fiUerp1 A [j-I~re(gtl1t solution of this by volume is then made it thu k(tone Htptate or l(hPI or tht llIixtlll or tlH~p I~lll as tlw lullber foinnt
REAGENTS HHt RESINS ANALY3IS
Resins SUITIIN- Illixlule I)f a parIs ot lll(IJII~lIllII(JIll Hlld j pnrl~ (If fthSi IllI glnmiddoto] IlHlll1I1thII Nhpl (l(rtiIlHft(l 1CPIlPi i 0 as (middot110lt01middot1 I hr 01111111 botl t((hni(ul-glu(p CnlilOlI amp VHIhi((I h(lIli(d~ COImiddotpl is a gooe1 r(sin~ soiYPllt ~Ihis lllixtlll(I i~ 11(111( (0 ilS 1((loll~Il(ltlJlIPmiddotllll(Jllmiddotl amiddotmiddotj ill thl ((xt (011shys(allts I)f thf~( a 1111 011](1 rl~ill oYlll(s tn )inlI ill lalJl1
R(IIrmiddotpimiddot((middotJitlltill1 iWiIiOl- [i-(J(middotl((middotClImiddot 1I~O (e p (agln Oil Ponl f1 gl 114 J solul iOIl in HO by 0111111( is UStl m I Ill llills pll(ipita nt
Po(- i ( (ol()icl ~lJ11I1 iOIl Ol t(8Iyen-A O-IlPI(lnt olnl ion of (igl~((1 Rtrl ra i ( H or gly(o~t tlill I lIIath ill I (p( ollyln((1 OIl(middot(plJool( j or nlly ot Itpl rlsills solnnl 1I(tL TIJl diglYlol Hipn Ill ((i ~ is (lis~nlaquo hl 1 Itll tillg Illl lolLttioll i 11111111 liP 10 ulnnl( nla Ht1li1l1H11i tl1Il1ltIIItlllP Hilt 1IIllI((1 If thl -oll1liol1 liOllltl )(lOIllI loud) II((IIIP of II drop in ((IIII)(IH(III( 11( plPtipinll may hI hlollgltt IIHI ito ltulutioll hy It(lItill~
SIECIL EQrllIE[ Fon HlIlImn 1) HESS AALY5IS
11I0T())t1~TIG ISsTH L)IEITS
8((1111 tylllS ofi IlstllIIllllltS i Ill 1lid i Ilg tltl C01lIllflii e ] (((Ioni( plW((lJl tI OJOill(hI (oJ II1Illll dolllJltmiddot II lOll el(h1011111 t OJ SPII( IOplJOtollwtpJ Klett-Sull1llllrSOll o1olillltlI and EnIYIl pllOt(l(h-tJie cololimettt han b(PIl II~~(I TIll pilotoflttolOIlIltll apptUPlltly is llot suited for thl pUlposr iJltHlIP thl (hllJlIh~Jjstj of n( l-ollsplllliOlI IlHHStl1lll waS SLl(h that thplp WlIS velY ltLpitllhullge ill the rendingS oil standing of the liOlllt iOll a1tlI rubbl1 nnd Il-ill~ plltipital iOll fltP onitL of prefmiddot el(llce fl(lIll tilt ltalldpoillt of gllntls pllri-iol1 of llading~ is us follow
(1) CoWlIlan dOllhlt 1ll001O(ltlIII1lH I01 IWl1 Iuphllt 0111(1 PI mo(hl lOH 0 COPIlHlIl I1I1iY(lsnl SP(ctI1I11holl1nHt(1 Ilwdll 11-WaYlmiddot1I1g-1 It Rlllinl II t j() mLL is IlCIUlIllPlldl(i
(2l EnblI pholo(lptlli( (olulilll(Il1 wi It (Ining- 1II11 110(IIIUIlHl tie filt lr rOIllshyhillatioll jtl lIllL 12middot112UGc51- villstllt (ap i~ ~(t1 10 ((Jlr nl)lOIptioll IIt tllllP Wlllll 1(IIilll~ HI hlill 1lI1lt1t A nitmiddot fill holding 11 Itlllll nmgllifing IIHli til flllilitatt lIlaldll~ IIPPluxilllllll 11llIII11111letl1 I(adings tn 01 lila) hc IIJ1l1l1fll(lllld 10(lllIy
(H) KlpttmiddotHlIIllnllISOIi (OI(lIilll(tP-So ~Ililllhll Iiltpl (lInrllinnlion of IIPillllXimiddot nwlcls 50 IlIJL IIln( (Ilgth I atillhl( at 1Il(middot~(middotIlt Till ill(ItIIlWllt IWIfOIIlIS Hn tisrt((oil~ wit It th( IlIa iI II 1111 filt hpi ((11 iji 111111 njij IIIl for IlIlIlI(I II nIl1~si on 2-S(tllolll (Jl oltlll glltllh 11111 (prilll wit hlt l(lJlo((1 a 11(1 f(IJ~ currentmiddot plon ~1(jlh (101l IIII plnn[ with 111 t (1 ahlllp W(J IllJL 1l( lig Hl llIi 1illlit it USP(IlII(S$
ltOl the JlJ(~(Il( tlt( Ewlrn pllOtolIl(1 de (oIOlinwhl i 11(Olllllll1H1(d as (hI IlOt eOt1PlliPllt alld ndaptabltmiddot il1trlIl1lnt rOl rout illl lnbolttmiddot t OIY alltl ly~(-
OTIIEH I~QUIII~YI
A lhplllIoI11 i(ally (oll(lollltl tlil huth wilh a l(llIun1l1l (1(11 hllsk(t pllllimiddot liOlWl [0 hoW il)Il YOllllllPI( lIa~k~ ltig ] L llihglmiddota(]( tylil(il oil ~ K O i1((1
A tlt(IHW(1l tielHr (mil 1lIl1td 111 Ipl 1Jr t It IIIIIjdlt wir It lHolol iImiddotI(1 Illld IClllollhl ~(lllI IlIl~kl[ 1111 lt it jllll(( t h()1( i II Ill ltlOmiddotml Yonnrp[ riellllisl)I 11( in stnlltIItlllllg I Ill I lPlI (II 11 of IPII)(l1tlt Hila IIn)UIII of (xIII(Itl saJlpp~ Illkpl1 (01 Ilnlll~~i~
bull
bull
bull
7 RAPID PHOTOME1RIC DElERlHNATION OF RtBBER AND RESINS
bull
bull F1(rJm 1 ~ UIIIltan 11l~IIlInIPIII lo UIIlallt-lllllplalul( ~(II(Inl-[lllrpose hath 11fil1l liS au oil hath Xlltl ~IHinl 1(IIIOIullll win 1Jt[PI 101 holding ~[j-lJll Yo1U1l1plllt flask dUIlng- (xu iOIl ur luJhl t IHI IIill IlIi is uot stlludard ltfJuillll1ll1t nIHl 111lIt hi 1Ill((1 b1 (hI Hllal~-t
Ilm1ll E JIItnslIlPil iIIit (111([ (Iltaslll(11 [1111 In(J nlHI K()(lak electric tinwl Ilw Hutpl H~ 1l~Id ill I1PIIIllIillillg )1IIIdillg (illll n((uInl(l~ 111 111lt minute unll luhllpl HIII1 Isllll al( l11(ipIIIIlP(] 111111 till tOIlIlPI 101 tinling hlHtillg nml (11 tli fUli Ilg 11l1iulls
AWill~ 01 It Ball amp I(wpllluill fol Ull initial lWUSI glinllillg of gtllyul(l UsU( Hoss-llal(]pslr IIWllifillIlioll of Ihl lInlllllHI 11Iil I I plIlIilll] with Xo 1
(~middot1Il11l) nl1d XII (iIIlIII1 (lPIItS LYIPX i lUl(l lOOmiddotml oInllHUilt 1IlI~ llloidltl witlt grolllHlmiddotglns RlOPflllS spr-ial mIIIi 11lx ItitUllIti IIllIkll wllh UIlI illlIlp 1111111 1111(1 gillS
10(1 12 CIIl iclllg h~ 1Ii jlll ill Ilillllllitl wHit gtOllIHI UnllIIPti IlId 1 em In dillllllll fOll1~p illlllllldllg lIbhll slutlon [fig A IUHllJ) 11)( jllpiul heakcr I lIJIIlI1fIIIIIlII11 t101Il Ihl W-1l1I lldUiIl low-fllllli 1IllkI wilh s[lout laquo(olning (llas WIllk Xo 11111(1) Till ll (toul I flatlll1lt1 hr (Ill lgl1lu glllliliIIOl[ing Plo(Il1m Ill IillltllIllI 11111 of Ihl gIllgt ruti aIHI IIIP sUIfa(( lit til( lIat insitle hottnlll of IIII )11111 nl( gIlltlIHI toglll)I wilh Itll(I~ ill 01((1 II) s((Ule the most II tisflnlory SulfH1 rill lil Illl I iOll
P~I(X WIIlIIt glI III 111( ll111L ill thilkms 10 II~( a It tIHS(~ III ([hiding luhl)(I Sfllll[llp
A Iolk Imil fill lISI ill diiltlill~ luhI 1111[111 H(Hy(Inl~ 1~T(lX 10middot1111 gllhmlllI (Pili Iifugp t 111H Ill]lillld wll It (011(1 1101111
lind (ork tupp (0 tit I Ill 2 ()
bull Filt1 tilk (fig 2 IJI 101 1)( with Ihl glltllunlld tublS ill thi o[WIati()n of
llOUling lIIIlillpli lx(nll illf jIIlI )lhIIIl1IY(I lIask IYIIHIlt ([illlluin l(slmiddot Ill At hp II11IPI a )Iuss lOI wit h I tIaltllll(l (lIll lIlS lI1ullIfnlul((l ill the Illhllln(()I~- fol this l1SI bill ii In (lilli(ll1t 10 -1(111( II PIIpound((( tit Howlwei tlte anilnblp filtpl ti(klIt1 tlll 1)111)111-1 lind was Intll lIhs(i~llll(l The fritte(l glass disk SII(S 110 rUlli1 lUll Ill llIlI in tliH O)IlIUlhJll hut hollis hlllk the liqllid II nil lPidlH in till ((111( PHill
Cuullipl(1))ipp(ll for tlllII~flJItng klotlls nnd uthI IlIgnnk Illnnis SlIInl pighin) III I (h li (Ill high alHI (III ill ([111111(1
8 TECHNICAL BULLErIN 020 e S DEPT OF AGIUCUUlUlUJ
bull
IHHH middotmiddotmiddot~Ollll of the ~Jl((iHI ~lnsswlI( reshyquilpd 101 [lh)lI and I(sills tllal~sis (lllss rod wilh lInttPIH(] (ml Loll alld tlitulatioll lJlll((I II]) 101 liSP ill bull IIlnlln~ sto1 solutions of IlliJlPI (olII1i lwanshydlltr -AIIlI lYIX ((1I11ishyrllg tulJl wit Ii 011( poillt (0) nIHI flIIpI stie ( J) I fOlllSP ill P[)lIill~ utl (llIdiIli (X( lels witlt shyout di~tlllhill~ the inshysulilhll Ipsidlp
bull
Glns pound1111])(1 ) jlllll in ((iamptl for 1( ill tltlm~rprljlJg- pighpll fllJlplpS HIIl1
bull (lnrin(d IXIIat to -llil ohllnlllI f1aI~
i(p-mollllt gingt hntl will llntit OJ 11I(lal J(IP (n] fOI toling- gIollIH plallt samp(
Halmiddotk for hllldhlg ill-llll middotPIlIlilnp nlHs IIIH ~i-1I11 YOlIll1pllit flll (Jig- 31 Alltolllnti 10(1-1111 ~middotI(lX IlIllPUp of IhI fq)p llsltd fOl Iitis with intpl(middothallg(middot
nh1t H(JlIlHI joint 101 rl1phl lPfIPIIIlg (lj 1lIhhpl fllld 1(ill lll((jpiltlllls
bull
FllilHE Had Iqllind fool IIJI(lill I 11 (111111111laquo llllmiddot alHl (I) limJ VfIlIlllllJi( tlak~
bull TIll itl1jHlIlWI of n Illb tlpl of d(Hdill(~~ III [gtJ(Jtnllllllil lllll~
i dblmiddotwmiddotpt hy Y (J( I _ j J i) t Illt riflllmiddot t tth~ n n Ii 11 111 h111 I t1loOIlldy witl nap lllltlIHI 1111 1l1id bpll tlll- HII lill(ll with (jtt11lill olutioll Hlld ltll If fla k It It [lllijljtnlld 111bhll nl
11ill lIll til ~tlllld all 111th Ill lillI Illmiddotforl 111l In 1(11 it j~ luhmiddotjlIll] 10 1111 0111 ilH (111(11 11[ Jpli~ Ii tllp wall TIll
10 TECHNICAL BULLETIN 920 U S DEPT OF AGRICULlURE
25- and 100-m1 volumetric flasks arc rinsed two or thrce times with tap water and then with cleaning solution al1tl watel as is customtny In all cases the rinsed glassware is dried in an inv(ltell position at 100111 temperattlre 01 upright in a drying oven The flasks used IoJ extracshytion of rubber Iron1 kok-sagh)z (Talllrl(((IM1 kO-8aghyz Rodin) are finally rinsed wHh the solvent to be used and are nllmnd to lt1Inin and dry under a ventilated hood Cuwttes 01 absOlption test tubes nre handled and cleaned aH directed by the manufacturC)s of the llhotoshymetric instruments used
RUBBER (CAOUTCHOUC) CALIBRATION CURVES
GENERAL CONSIDEHATIONS
The lubbeL hyclroc~rbon stau(ild is pllpa 1((1 by extracting the rubber from guayule bssue ac(ordll1g to tilt SPCI1((-Caldw(llmethocl (5) 01 by the Holll1lH-HaasiH modification of this method (p 2) The air-dry extraeted ltlbber is dried furtlllr in It vacuum OYCl1 with 30 inches of yaCH1Il11 at 63 0 C for 4 hOlIlH Till rubhlI sbindanl is preshyserved h1 It clos(cl contaim1 sto1(d in It r(fligellltol BCfole th( samples nrc weighe(l out the unopened cOIlbdn(l with the rubber i~ brought again to room tllllpelutnre
Two stock solutions each in triplicate from separately extractml standard rubber satnples nre prepared-the first sct of (-111(( containshying 01 percent 01 1 mg of luhbC1 ])(1 lniHilit(l and the other 02 pershycent 012 mg of rubber pel miJlilit(l TIl( (I(~il(d w(ight of rubb(L contiiinec1 in It known VOlIl11e of th(~ solycntis withdrawn Irom Il
burette or pipetted and made up to 25 m1 the standard volume used throughout the procedu]e
The rubbcr samples (01 and 02 gn1) for the stock solutions are weiOhecl out to an aCClllal) of o~ mg on nn analyti(~al balance The rubber is best mnnipulated by mNlI1S of t1l( stJai~ht hlunt-edged top of It cork knife With a little prnctie( OIl( (an leltlily sepnrate t)w desired portions by pLeSSIl1C from aboye Further subdivision Is mndt on a stout PVllX at(h glnssnt lla~t 2 mill in thlkne~s By pressun f10111 above and sheuling aetlOl1 Ye1~ small pnrbcllH can be separntetl so that the requit((1 11l110unts (un 1)( w(igh((l Ollt accurately The rubber sample is then divided into sl11a11 piC(es on the special watch glass by meanH 01 II coll Imife
One mil1ilit(gtl of lt1i isobutyl ketone 13 js placed in It special 30-m1 trituration beaker (fig ~B) and the fine1y diyilt1ec1lubber sample (01 or 02 gll1) is udd(d and heated on a hot plate under n ventilated hood to Il tempelature jllst under th( boilin~ point of the olvent A special glass rod il used t () t rit II ate the sumple (fig 2 11)
When the rubl)(r hll d issohed so as to makl a hOll1og(J1lOUS geUike 111I1SS hot methyl isohutyl ketone or an oI the other luhb(L solvents recommended (t aIJI( 1) is add(d and niicd with the rubber soltItion
31 Diisoblltyl ketoul WIlS not aailab1p (Juring ValtimC l1Cthyl isolJutylletonC 1II1ly be substitnClt1 11111 it is not a~ Cf1kiCni In Illis olllntion If the IllttC1 is used It is b(SI to pl Ilw fimlr diillPll Iubhpl palll(s slan( oPIuight in Ih( solvCnt lind 10 (OPl til (onlalll1 to IllinilllizC elIpornt(111 of sohPIII bpfolp wa( Is nppliecl to completp nlutioll
bull
bull
bull
bull
bull
bull
RAPID PHOTOMElRIC DElERMINAlIOX OF RUBBER AND RESINS 11
The mixture is tllll1sterled to It 100-ml yolumetlic flask with sevtlul washings of hot solvent cooled to n s(uHluld telllpelatUle and madtmiddot up to volume with the saIne solwlli SlwtiaJ IHl(uutioll mllst be takell in transferring t)( lubbCl solutioll to till YolulIHtrie flask so thnt llO rubber is lost It is cOllytllielit to illSllt It j-ill(h funnel in the ne(k of th(~ voiumptic flask to pOll tll( lubb(ll solut ion ill OIl( OLWlHtion into the tube of tht IUlll1ll with Ihl aid of tIl( glllss Iod nlld 10 follow illlshyl1eilintely with S(gtllnl ~Ynshings of hot S() I(111 whkh lIl lilst pouled 1nto tIll btll PI 1I(ld dIIleUy OW) till 1unn1 aId IhpII t1I1uugh Ill( funnel
H time hi not all objllt it is uls() flasible 10 p1alt Ihp linely diided particles of Iubblt ill tl( flask toJ1tuining Ihl sohPIlI 11(1 allo it 10 stand until til( 1lIbbpI is dissolYld TIl( llIblJll ioluliol)s alp slolpd in Ihe tightly s(ojlP(1(d OIUllwt lit f1nks in a ((lol dark placl Thel they willltIIlUlIl (OlUilallt ill Idut 101 an indlfinit( JlPIiod
Two ellliblHliol1 (IlP~ flIP IIltl(l(-OIl( 101 o~ gill of tisHlIP (ollin illshyhw 0] to 10 PII((Il of rubb(I ((1lt)middot1 to U mg of IlIbb(Iill tt ~)-1Il1 yo1ullll) and th(middot otlHl for ()~ gil) of tisslIp (ollaining 10 10 ~l() peLshycent of lublJPl (O to 10 Illg of lulllJpI ill a ~)-))Jl YOIlII1IP)
(Hns HlJ 111 TO 1 II~IWEX( (II BIIII1EH
III oldl) to ll(llllP (ITOI (0 II Iltinil1lIl1l a lIitahl( lllillobllllltp is lIs((lo Jl((lpn (P IhI ~lt of stal1da Id solut iOlls 0 f a Ii ng (OJllllllllll ious ill til(gt (III)(r( Ol 10 1 gt(I((lIt of LubbI In (11( PI(sPIII WOlk th( 1111shypIoypd HlhlHIg mic)obm(ltp Il bullJ) whkh lIi(IlJalpl dlli(I~ 10 0001 1111 was Toulld sntisiadOlY F(OIll n lll-pltIllllt -talHlulIlllbwl solushytion in HSlIitnbh solnnl lt[lIiIlIUJl1iiat( aliqll()l~or n) Ol o~ n and ()t 1111 al(lllla~UIpd (Jilt ut n stalldUld ~Olllli(lll tlIlIJl(1atulp (~) C ill wlitllmiddots labolulol) I IlIIHIl-of II lllillOillIl(tlt illio ~l-lld yohulI(lie f1nks ploid(d it h gla -(OPIllIS gllollgh of 11ll lubhpl sol Pili i~ thllI addltl to (tl(lt flask to IlIak(1 l 1111 Ill1I IUI(middotc (0 t hl all)ollllt of lllbOPI solutioll ]ll(yiously nd(lpdbullflll DI ntl 01 JlImiddototlmiddottli lolloid solu tillil Iras h(PIl Hddld lIP (bhpl is JlI((i pi III tpd IIlld SP(middot(t )opl)()tolllshyd(gt( 01 (jIOlilllltp) IPallil) an IllHdp 1I((OIdillg to 11ll JlI()(pduJ( Oil shylitwd Oil pagp 1middot1 Th( 1(ldillg~ 101 palmiddotll (OI1((III)Hlioll alp 1I(Iaglt1 anel plotttd Hgaillsl t( ntilligllIlll of 11))1 hI n ~)-1ll1 (jIIlIlH 0) [gt(lClntagl of nlbblI (nltuln(pt 011 tw bnis of tl2-glll lilsul Slllllp1(gts and aliqilOt olulllt IH(IOI 101 (itl ]1I(J((dlll( out lilll(1 Oil pagl 1middot1 This PI()((lhll( i ((l(alld t win ill (a(1 (11( II slandald llIbbllsolushytion was PI(gtllllpd IIOIlI slpa latll XllH(1 ld 1 a utln)(l lllbblI 1 III pips TlwcOlllpl(tpdtlla alp pol(l (1) (loldilla pap(laslrowl1 ill figulp I
Tbl )llO(p(II I ill lllilking a (Uln rOl I to ~ jiI((lIt of JlIlJh(1 i~ simi1t1I to (hat rOl 1Ill l1IlP ImI1 to 1 JllI(PIII (x((pl ill a f(middot dptnils The quinlu]lli(Htl aliqllols a 1( sput(d Ht (lI 12 a j 0 (78 n alld 10 mg ])(gt1 ~i-1Il1 Yolunl III sNuIing thp 01 Illg pll 2)-Jll1 YUlll))lt til( (gtIO(ltlIII( outlillPcl ill IIIl PIp(tding pnltlgllIph is followpd In the rllngl 1 toj Illg )IN ~)-1I11 OtIIl1I Ilw (lsi 1(lt1 (oJ)(tlllltlliollS of lubbpI alP s(gt(ul(gt(l h IlIPHsuljng alhplOi- with Xnlional BIII(atl of Stnndlld~ tltllsf(I pip(Ws flOIl) tltl OI-PlIl(1l1 lII))ll sol III ion
12 TECHNICAL BULLETIN 920 U S DEP1 OIr AGRICULTUHE
RUBBER IN 25-ML VOLUME(MGl
100 1~__middotOT5___ITO___15__2~O=--_bull 2r5_---= bull 3rO__~-_40 bull99
98 shy(I) CI Z
~ 97 ItJ II
~ 96a f-IIJ
e95 o l
94
93
92 ~__~__~__~____L-__~__-L__~L-__~__-L__~
o 1 2 3 4 5 6 7 8 9 10 RUBBER (PERCENT) bull
FIGURE 4-Cnllbrntioll curve for rubber in 02 gill of gt1n~ule tissue containing 01 to 10 p(rcpnt 0 lllbhlI (nlnllillg~ (Ill 1111 J~pl~ll llhooplf(middotttmiddotlc colorimeter with 720middotmu filter und amiddotml uperture the 01 divisions required in actual pracmiddot tice for photometric IclHlings arc olllittltd)
Similarly hl the range 5 to JO mg pel 25-ml Yolume the desired conshycentrations of rnbber urc measured from the O2-pllmiddotcellt solution The complete data lire plotted on semilogtllmiddotithmic pttpel as shown in figure 5 A
STANDARDlZATJON AGAINSL G1IA111 ETlIIU 11 ETHO()
1he alternate ploee(lule of stt121l1ald izing th~ IneHell~ method ngninst the Spellcc-Cald well method (II) altholl~h flaSI hIe 18 not adVIsable because of the extra work J(quiled ancl the introduction of the expershyimental error of the benzene extraction method
HESINS CALlBllATION CUIlVES
The procedure for constructing cal])lation eUlves for resins ttIlulysis is similar to thtni outlinlltl for lubb(l lxcept that resins exndate of gunyule is lIsed as the resins stundard The resinolls exudate disshysolves very readily in the resins solvents listed in table 1 It may be prepared in two ways for use as a stnndard-the clean exudate as bull gathcrcd from the plants is dried for 6110mB nt 65deg C nt a 30-inch ltcuum or the oXllllate is dissolved ill acetone and filtered In drying
bull
bull
bull
RAPID PHOfOMElRIC DJllImlMINAlION OF RUB BEn AND HESINS 13
RUBBER IN 25-MLVOLUME(MG) 2 3 4 5 6 7 8 9 10
r~
eo en ()
90
f--70z Q ~ 60ltl LIJ a ~ a LIJ 40 E 0
0 50
~ 0 ~ I 30 0 ~
A 20 I I
o 25 50 75 100 125 150 175 200 225 250 RU88ER(PERCENT)
RESINS IN 25-MLVOLLIME (MG) 2 3 4 5 6 7 8 9 10
1--90
80
en () 70
I z Q 60ltl LIJ a
50 0
a ~ LIJ 40 E 0 0 ~ I 30 0
B ~I20 o 25 50 75 100 125 150 175 200 225 250
RESINS (PERCENT)
lJIGunE u-Cnlibrutioll cUve for (il) rubhcr in 02 gill of gllnn11c tisme conshytainingl to 2G perc(lt of 11IUU(Il I1na (1]) rpSillS in 02 gill of glI1~l1ll~ tissue (ontnining l to 20 nelecnt oC l(sin8 (U(ndings Oil 1111 E(lI~1I llhotollectlit colorlmeter with 720-mtL filtcr and O-ntJ aperture the lO divisions llquired In uctnul prllctlce for pitotoulPtlie PllllillgS tlre omitted)
in vncuo arelntivply HllHlll qUllntity of (xutlnte is plllcel] in a lalge dish since the mass rOHmS nt the beginning of the drying process Pracshytically ull of the ne(tone is evnpollltpd olf oyer a steam Ol WItter bath and the residue is dli((l pnlYllized in It mortnr and preserved by
14 lECHNLCAL BULLErrN H20 U S DEPl OF AGRICULTURE
drying as indicated for fresh exudate In all ClSeS the products are stored in airtight containers in a dark coul place
The usualllnge of resins from gunyule tissue is about 2 to S percent on a dry-weight basis For work with this plaut therefore on1~ one curve is needed A typiCallesins ealibrntion CUlTe is shown in figure 5B
PnocEDuuE J~OH RUBBER ANALYSIS
Duplicate lXiLllCtiOllS arc made for each tissue analyzed and duplishycate photometric readings are made for each cxtmctioll the final value therefore reportcdreprescnt- nn avcragc based on the four phoshytometric readings
Thoroughly mixed O2-gm samples of the finely ground tissue are weighcd for analysis on the basis of l11oistUlc-frec tissllc The samples arc weighed to an accuracy of 02 mg Oil an analytical balance The method of deriying factors for making eOllections for moisture in samples has been thtailed on page
The weighed samples arc trallsien(c1 to the 2-m1 volumetlic flasks with the aid of l-inch glass funnels and 20 m1 of methyl isobutyl ketone is added to each flask The contents in the Hasks are heated m a constant-temperature oil bath at 115 0 C for 30 minutes uncleI a yentilated hood rhe flasks are removed and any adhering oil on the outside is wiped off with Kleenex 01 H similal cellulose tissue the C011shytents of the flasks am cooled to a standard tempellltule (25 0 in the writers laboratory) in a constant-tempelutllre ater bath provided with a motor stirrer if available and made up to volume with the solvent After the contents are mixed the flasks are allowed to stand for a few minutes until most of the insoluble residue settlcs to the botshytom The extracts are then carefully poured into JO-m1 heavy-duty centrifuge ulJls so as to include as little as possible of the settled insolushyble residue The centrifuge tubes are stoppered with cork stoppers and the liquid is clalifiecl by centrifuging for 10 minutes at 2000 revoshylutions pCI minute The clarified lIquid is poured into 25-m1 volushyl1Ietric flasks plOicled with ground stoppers It i impoJtant to pour off the clalificd (dlart in lWIt a lUlllie that the ill8ol11ble cNi(hwis not Sti1((Z1tp A 1-in(h funllel is plncCd in the neck of the volumetric flask A filter stick (fig 2 D) is inserted in the centrifuge tube through he liquid so that tlH enlnlged palt of the gtiek seals off the insoluble residue and a small portion of the exmet in the cone point 1Vith the index finger the stem of the filtel stick is thell held against the side of the tube towllnl the analyst who holds the tube with the thulllb rmtl t11illt1 fingCl The txtlHct is thell poured off easily into the yohunetlic flask without distnrbing the insoluble residne The COllshytents of the Hasks are then ))ollght to the standard tel11pelatme in the constant-tempentl111e wnter hath
The reagent blank us(d wit h the spectropllOtoll1lter 01 (olorimeter ig prepared as follogtvs ) 1111 of methyl isobutyl ketone 01 other solvent used is pipetted into It 25-m1 yolumetric fiask and 01 ml of protective colloid solution for rubber is added the mixtule is made IIp to olume with acidified Oil-pelcent ethnnol and mixed again the rcquired vo]shylime of the mixture is poured into a cuy(tte or an absorption test tube
From each plir of tissue extractions to 5-1lll aliquots 01 the clarishyfied extlact at the stnndanl tempCraLule ale pipcUed into 2ii-m1 volushy
bull
bull
bull
bull
bull
bull
RAPID P1IOTOMElRIC DETERMINATION Ol~ RUBBEH AND RESINS 15
metric flasks and 01 m1 of protective colloid solution for rubber is added to each One additional5-mL aliquot from each pair of extracshytions is similarly prepared to serve as a key to the standing times for the final readings as indicated in table 2 These additional aliquots are first made up to volume with the precipitant acidified Do-percent ethanol mixed by carefully inverting the flask three or four times] and allowed to stand for 4-minute periods before the reading is made on the colorimeter Vith these preliminary rendings a~ a basis the standing times for final readings are taken from table 2 For example if the colorimeter reading in rubber analysis at 4 minutes is 655 then the standing time is 15 minutes
The two rell1Lining duplicate aliquots for eath extraction are then made up to volume with acidified D5-percent ethanol mixed by careshyfuIly inverting the flask three or four times nnd allowed to stand for the required number of minutes as established by the preliminary 4-minute trial readings (table 2) before the final colorimeter readings are made on the contents of the flasks
TADLE 2-St(llllliIlU time for variolls (OllccntratioIlS Of rubbcr or rcsins aftcl iJleaipitation bcforc colorimetric readings mc macle
[5middotml aliquots of rubber in methyl isobutyl ketone or of rcsill~ in ncetonylncetonemiddotcellosol e 3middoti both made up to a 25middotml volume with pr~cipitantj readings on lvolyn photoGlectric colorimeter with i20middotml (690to iiOmiddotD11) filter and Umiddotml aperture]
RUDDER I
Range of colorimeter Approxima(e S~nuling i Rnnge of colorimeter Approximn(e Standingtrial readings after 4middot range in conmiddot tJIIIG for trini r(adings nfter 4 range in con tifillnlOalcor minute stunding time tcnt In tiSSU(l Unnl I t I t (rending IIlIDU C stum Illg lOW _ tent III Issue reading
Percent Villlits II Perfe~lt Jfinul 955-999 bullbullbull bullbullbullbull 09-01 00 01-03S bullbull ~ _bullbullbullbull_ Jl-O9 10 743-954 bullbullbull ~ bullbullbullbull __ _ 43-10 30 1420-550 bull ~ ~ 137-94 5 6_3_9-_74_2__bullbull_ bullbull bullbullbullbullbullbullbull_-_---- 6__8-_4_4---___ bull ~ ~ bullbull ____ MQrcthan 13ibullbull_-~_ _ ____ 15_~elow t~ 2
RESINS -----------------------------~--------
957-999bullbullbullbull ~ 139-01 60 11419-amp11bullbullbull _bullbullbullbullbull ~~ 13~5-939 10729-956bullbullbullbullbull_ Ii 25-1 middotJO 30 ~gtl2-40(L bullbullbullbullbullbullbullbullbullbullbullbullbull _ 2025-1320 5 595-728~~~ bullbullbullbull 8 as-G 20 20 IBelow 292 bullbullbullbullbullbullbullbull- More thun542-591 _bull ~ bullbullbull_bullbull_bullbullbull 038-039 15 2025 3
I Precipitated with O5middotplrccnt HSO in 05middotpercent ethanol When the npproxilllull concentrntion of rubber or rcsins in solution is not known trinl colorimeter rend
ings atmiddotJ minutes s(nnding till nrc mndelS n guide to the required finnl standing time indicated in the last column III prncticc UII cxtrn nliquot is prcpnred for precipitation and thIs is discarded after the trial reading is mnde
3 lrccipitnicd with OmiddotpcrccntlhSO ill HO
PnOCEDunE I-On UESIliS ANALYSIS
The procedure fol resins unulysis is the same as that indicitted for lubber analysis eomiddot(I]lt that f he -olyent js acetonylacetone-cellosolve ~)-7 tht precipitant js O5-perctnt H~SOI in H 2 0 and 01 1111 of the protective colloid solution for nsins is added to each 25-m1 flask conshytaining the aljquot of the extract before the precipitant is added
PnOlmmlHlC INSlHu~mNTs UECoIUlENDED AND CALCl]IAlION
OF UESurlS
Photometric readings of percentage of light transmittance (T) ale made on the Coltnum double monochromator spectrophotometer at
16 lECHNICAL BULLElIN 920) U S DEPT OF AGHICULlUHE
750-111 wave length or renclings n1( mnde on a colorimeter pLoic1eri with the monochromatic filter eOIl)Il1l1tioJl for sllecting the npploxishymate wfLYe ]cngth at 750 1Il~ For routine deterlllinations the Evelyn photoelectric colorinwt(r ployided with aTW-lllJ filteL is IC(0l1111HIHtll
The liquid in hich the preeipitnted lubber uld rcins are susshypended is pOll(d very cHrdully down the ill~idl of th( clette o absorption tube to lLYoilllllC fOLll1ntioll of ail bllbblls Aft( LUbbet find resins preeipitation wlwn the EnLynpho(otkcllie (olo1imetll is used the readings are nmde nft(L thl standing tillll- hOWll in table~ It has been foulld (OIlllliellt to 11lPtipilatl tublwr 01 llsiIlS from the aliquo(s at ~-millute illtlLvals This allows stlilieipnt tillle to check the eOlolimet(r and to makc 111( lNHlings Vlwll a ehangp is IlltHk fLom onc rending 10 the l1lxt it is advisablp 10 llle the clIvctte 01 absorption tube nt lpast twkp with slllall p(Iltion- of the llllltiol to be leitd
After the colorimd(L lluding lta e becll Iltndp till IlIl II igllIlllS of lubbel or resins or thc lpL(el1hlges pnslnt in Ihe aliqllot are r(u1 from cal ibmti(Hl (urVlS (fig~ 4 and raquo or from plepn Led tables of eqllivallBts baecl ill each (liSP on (x[lerimPlltnl data The results are expressed as percentages of dry weight (S hours drying nt 100deg 0) of the original tissue The errol lltle to lCflyjng the insoluble residtH in tbe voltlllletLie pxtLHclioll flflsk wlwn the pxtrnetis being mnde up to YOlllmC is V(ly slight sinlte only (U gm of tissue is used FOLroutine allalyscs lhis ery slight eLlor mny be dislpgnltec1
EXPERIMENTAL RESULTS
The experilllCnlal reslllts Oil hi(lthp method- of tU)lPI and l(sins analysis a le based ttl( d icussld blicfly hlrehl
PHEPMINrlON OF SAlULES
No difliclllty was expPtitI1(ed in pltparing slmplls of llllrscly-glOrt guayule plants 1pss thnn ~ YPH1S old 101 rllbbpl alld IPSills analysis In the cnl of Odll filld-gl()n gllayull plants PIIOtS hopel mtty be introdmp(l by the custOlllalY Jlwrhod 01 pICpalillg Ihp sampl(s 101
HlutlYHis as is lwipfly i n( ita ttd ill th is s((tion Smh enOlS do llot nffCct the ])lCcisioll O[ t1H llwt hotls for LllbbtL n nd Il~in~ nnn I sis i nee till) are due solely to tIl( tbsup--ampling (llo(pdule in thi (a~e of oldeL field-grown plall TIll 1lllt1lOcl of salllplill7 fipld-gl()l1 plants JllOLC than ~ Y(HrS old thenfort Ieqlliles iurtlHl jnttigntioll
lgtAHnOILr~G FOR HEllOVAL OF UUVLgtS
Parboiling which (onisls in boiling gllltyule plants in water [OJ
8 to 1~ ~ninll(s ~s col1llllonl) uSNl a~ n llHans of Itlli rCnl()y~l prior to drymg nnd gllnllng It I~ tHI([())P ll(e~Sllr to ltItLeLnunc all possiblt~ eflct oi tlti PLOtPlllll( )ll (Il( final results Exp(liments have sh(nm that (helt i- fl Flight loss ill til tmiddotjght of lOO(S and 4(ll1S In I typi(ul lXpelillltll hlu1llHs of ~- ii) -1-ytII-old gllllll( pllllb were Italnd at randolll Olll ( of talns wa- paLllOil((1 and the le~es (1( haIHI-pi(kpd [lom till o( hpJ Ht Both pis (1( dlipd for 48 hOttlS at (i) C in a llI((lwlli(al (011((( ion Oyell Th( lpsult are SUI11111I11izNI itS follows
bull
bull
bull
bull
bull
bull
RAPID PHOTOMETRIC DETERMI~ATIO~ OF IfCBBER A~D HESI~S 17
Dry ucilht lust ill lariOilillf
Plaut (pcrcrllO 1 1 -I2 ___________________ _
213 _____bull _____ bull __ _______ ___ ____________ 12 2(
pound(111_ ______________ 1 R
4_______________ _______________ __ _____
A __ bull __ -_
The efred of parboiling on till final lllalp i SUllllllatmiddoti7(middotd ill figmc G Rubb(1 lecoYelY w(t about 1 percent higher for parigtoillltl plants and lEsills re(ovelY somewhat o-er 1 i)(lr(lllt 10Wlr The (Ii tference in lublH-l r((o-elY cannot be ae(01111tltlt1 fot by loss in dry weight _ due is to be found in a study of thE grinding lwhadol of a parboiled and an unpnrboilEcl shrub The grinding of the patboiled shlub in the hnml111 mill is much fadlitated and ns a rule for tissue with a rubber contCnt below 10 peteent llO aggregates of rubber deelop in the 1Il11ehinr during the (Jpelatioll Yitll the unpnrboilNl shrub some dillictdty may 1)( (lxppliellrl(l Sill(( sOllle of till sti(ky ltxlldutl Oil the plant may scI( u nlldei for the fmllHltioll of lublH1 ngglPgates Til is apparently explnins the npparlllt los in ruhbpl frol1l the llnpariJoiled hrllb as eompnlelt1 with thl palboilld (fig (i) TI1(loss in r(sins
II
RUBBER
10 f-
Ishyz LIJ 0 0 LIJ 0
9 --RUBBER -shy-------shy
-- RES INS -shy---shy-----_
IJ) 8 I--Z IJ)
LIJ 0
0 7 f- RES I NS -0 -shy0 LIJ III III J 6 f shy0
LEAVES REMOVED BY PAFltBOILING
5 f shy -shy - BY HAND PICKING
4 I I I 35 30 25 20
SCREENS (SIZE OF OPENINGS IN MM)
FIGlRE Ii EtIe(t IIf pnlticlp sizE Oil lEcorPQ- of rubber lind (iiil1s when lEgttiye wEre remond hr Pl1liloiling lind h~ hand pi(king ((Dlltrol) plllllt1lt groUlld in t hammer mill
6114038-46-3
18 TECHNICAL BULLETIN 920 U S DEPT OF AGRICULTURE
recowry from pUboil(d shrub may be due to the loss of the resinous exnc1ate during parboiling This exudate forms ns It SClim on top of tlw )iquol in the tank
On the basis of t1wse results the recommendation is made not to yaly the nwthoC of leaf lemoYal in any 011( lNi(lu(h project Then fltirly compalabh IcmLts should he obUiined
70 ~------------------------------------------~ LEAVES REMOVED
BY PAR80lLING ____ BY HAND PICKING
60
-I-Z 1amp1 0 50 a 1amp1 a
en 1amp1 gt1amp1
40en gt-CD Q 1amp1 Z
I shy 1amp1 30 a l shyx C)
1amp1 ~ J 20 I shy 0 I shy
10
O+--L__L-~__L-~~--~~~~~ o 10 20 40 60 80 100
NATIONAL BUREAU OF STANDARDS SIEVES (MESH)
FlGntE T-lJiMlil)utiun of l1Ultkh si~(s of gnll~II( tiSSU( JrIOllll(l in a Ball amp 1ew(1 mill to pass six dllIerNlt S(I(euroII 1(IlYes Iemoved from plants by palmiddot boiling 11(1 hand picking ((olltloll dpfo1iatld plants dried to 1I lUoistufl l0I1t~nt (If 01 to o) 1)(ICl1It ground tiSSlli IbalH1 1() minutes ill II ~i$hel
bull
bull
bull Kahn shuk(f
RAPID PROTOMETRIC DETER~UXATIOX OF RrBBER AXD RESIX-i 19
GHl~DIgtiG
bull Th~ entire pant 01 plant l)iHt a~(gt fl r(ll it pllllIIirU1ry lSillg fur J hours ntGi~ C prIOr tD t 1( plChmll1atmiddot rLlmhll III a II lItmiddot or n Ball amp Jewell mill ~n llltllysis of paldch lzP- nftl~l (oar-( IIindill shows that tlwy ar( about tIlt llllH fOl parbojlP(t awl IJllllluhoileu hrubs I fir 7)
The coalilly gloUllll ample i-- thPll Ildlll forI toUtmiddot at ni C afnr which it ha lllilobtllL(gt output of ~ llllut lII hmiddot- dptPlIIlilwltl by drying submlllpil- at 1110 fot hOtll- TIll 1 IIIIll i lltllt lmiddot0l111d hi a IluninHl mill TIll mo(lel uP(t in thi IIIk i 1I Hu IIIOilll mill as IllUllifill bv Hoss nnt Hartlet ( 1 -[1lt111- with n1ll1l1 pldushyrations ittI lilnbhell b rill HanlIolll V0ll11nHiol1 ElIillllmiddotrill (0 The size lutllihl11 iUlJnole So I ( 111m t ~ II t HUIII Xl) ~ I L~ 111m nnd So 4 lillllU1 11 ttllilhmiddotj 0 r tllP Imiddotlult~ p(lln-It willI t11(e Sll((IIiZtS with )arl)Oiltll awl uil)Jtllboiltd hrlll b lOwl1 in fif1l1fmiddot-- This hows t tnt 1middottttIl ~(I 1 llllll (Up jlllilnl IHlt that
r------~-------r--- ~ --r IHAMMER-MILL SCREEN
O~ NO1
NO2 ---shy U NO 3 ---II
I
bull lL
z
r ------ l 30 ~ gt III
i I Imiddot
i ~ I
I 1 I I
~ 20 I - 1 iii 1[ r 10 ~ ~ ~ I _ ~ I r A bullbull
o bull L-~__~__~~__- ~~ 20 40 60 80 100 40 60 80 100 200
NATIONAL BUREAU OF STANDARDS SIEVES (MESH 1
Yutln I i-tlillltiuli Hf pur id lZt f ~naY1l1 t middotnt r1 lI1 i ~ a hatlltlllI 1IIi11 to 1111 Lx IHtllllH middotIn Lt-anmiddot tIlllunl loy la1 litkh~ omrl t 1) tHul parbuih~ -t B ~ thmiddotfuliufptl ]~lahr thpt tu tt fit t 1 It+gtr-tt1 Jnui~tHn eunttlIt _~rnlitl tl~UP ltakmiddot~~ 10 UddU it~ 1 rtmiddot4~pt~middotK1~r ttakt-middot
bull So 1 gingt- 11 tt-liuin-Iy ltr~pl [lPlItl1tat of iilll 11animiddotImiddot- Eqltrimiddot tIlllll hnnmiddot llOWIl dutr fll llltldllllUU xtlutioH 11pound lnhbll lIl lP-ill frolll IolUlIl ~tlaYlllt tl-IlP by dlt IJwtmiddotlUlmiddot lItlilwd oil Ill 14 - 01
i-mllt 11111- -lwltld hi INd I li~ Ii I TIll lllhtIlttj of Itiu~ So 1 (lltll j thnt 11middotmiddot01middot lttwmiddot to amplil tltt Iollllli tilt art lpdnn ib
IntIIll ll~ i po--ihJI with tI lLllit Ilfltl[lll1t It honld l Plllplw izmiddotl rImt ilt tht h of -allllhmiddot with l lllblPl
~ontlnt of ill PPltllt til lIilll it i tlllt pll--ihl 10 11-middot t(1i Xli L
20 TECHNICAL BULLETIN 920 U S DEPT OF AGRICULlURE
Even with screcn No 2 difficult due to rnbbel tlcrltreCtlltiollS may be ob tl
encountered In thes~ caHeH it iH lWit to parboil the shlub fOL leaf lemonll and finally to dry to about 1 to ~ P(l((llt of tnoiibl1(l pound01 b(~t results jn ~rindillp in tlH hanmHl mill
It iH aclvlsable to provic1l thc hammer mill with a ground wire Hillel the presence of static electric (harges 011 tll(middot partkhH will ealls( Home of these to atlhelc to the inside of tllP (olltailWr OJ lila eallsc OI1l( of till pULticl( to form ngg1(llatls EIIolin lalllpling fl01l1 fhis SOI1I(I mlly be (onsi(h1llbl(middot
A1I10l1g the Holnllts with high boiling point that lIlay Ill IlHld in rubber anal)Hs I1IP Illllhyl n-alllyl ketolle methyl ioblltvl kptOIH diisobutyl (tOIH blltyl tHptate llethyl amyl 1Ittail (middotthyl(middotlllmiddot gly(ol diethvl (middotther and n-bntyl (middotthel (labl( 1) TIHse al( also I(sin 01shy
middotent but th( 1(~illS n1( held ill olution by the rll1)bpl pl(l(ipitant tthanol wll(1 lllbb(r is 1)J(lipitatNI (S(ll tabl(s alldmiddotl) On tIle basishyof the lxpHilllPlltH tll( btsf nil-round lolPlli -rol lS in 111( PIlHPllt method is lt1iisobutyl kPtonc wld(h was not IIltlllllfaltllllmiddotd ltIlling Vodd Yflr n A suitable Sl1lgtstit ute iH llHthyl jolllltyL htolt whi(h is l(porhd as llolltoxit UJ)
Clllos()IY(~ (ethykn( glYlol monopthyl (tIH1) blltyl earlgtitol (di(thyl(ll( gly(ol llIollobutyl (ti1(r)~ and acttonylacetOll( may be used as resins sohrCllts (table ] )
In the earlipr work with (sills analysis cpllosoly( alolle was selcmiddotet(d as a suitable solycnt Aitholllh (ell()~oh( alone is pxc(lllnt its rplllshytiwly gwatlL iscosity 1(I(b to bubbl( formation nft(I (SillS pr((ipi tatioll Thi- increased thp (xperimentnl (LTOI OIl of tltp othll I(sins solpnts tI((tollyla((tolH has the proppry of glpatly lNlulingshydH(OSity 11(11 altld(( 10 othr liquids This sohpnt tlHIeforl wa addp( to ((Uosoh( in slIflici(lJlt tlllIonnl to OPI(0111e the dinieulty On the basis (li~ex)le1inwllts ~ purts oi~ a(donyla((tOlll to I puts of (elloshysoh-f (bolll by olume) as Splldcmiddot(l Thp 01 hel Hoh(nl listed hutyl clLlbitol at l(llst the t((hnieal-g1lld( ploduct uSNl is appal(ntly not as good as eithe of t1w ot1(r two () a (ombinatioll of tlWSt
The SOlVllIts JOI liSt in tumlyzing artifkial lubbel$ hy tlw pr(senf method appllLently (lcllIHl on th(middot kind of llI))(I lIp-ityl (Jxidt is suitable Ol BUlla fi and hutyllthlI for butyllllbbl Tlwse reagents IlLe technical g1lld( Calboll amp CtllUil1t Ch(lllilai (OIP This Hllbjp(( hilS not bepn (XtpllHl(ly illwtigated by till WIit(I
PIIECIIIIJ-
All tlst fOl Ih( adlqlJalY or till IHllipitullb ll(Ollllllentillllll11Sl bl baset] on the plctisioll of tllP final I(snlts oiJtairwd with the methods The )redpittlllts s(1e((( n HpJ (xtcllsi( (xp(IimPlltatioll all HatiH~ factor (Hee fig Hi 111lt1 tabItmiddot (jH) Ext(IIin tllts llllTild Ollt hanmiddot shown that H Hatil-gtflltlOIy [gtIpeipitallt 101 1lIbblI is (li-p(IT(middotnt HzHO (c p reagent nil POll sp gl U-lmiddotJ) ill li-P(l(Put (tinmol by vohmlP liol (tllayul( Ipl-gtinl 1l)-P~ITImiddotllt H)~o ill Hl) by ollln( ii lL satishyfaeto7-y l)lp(ipitunt A solution of 1 palt of H~~o to 1 part of H~() (1-1) iI2So1 nnd abo yarious int(lIlIPdiat( proportions of tlllse suhshystanCPs giyp fait 1(511It8 but with till inlIptl(l ill [h(gt ratio of H~S01
~
bull
bull
bull
bull
bull
RAPID PHOTQlIEfRIC DETEMIlXATIOX OF HtBJER AXD RESIXS 21
to H 20 the )olutioll becollles somewhat vbcou5 and precautioll Il1Ult be taken to ttvoid bubble formation When it i5 poured into tilt Cllvettes
It should be lloted that both of these precipitants have an ftellleshymmiddottion It was found that when XHjOH was used in the rubber preshycipitant in pInt of H~~O~ the readings were -table l)Ut were not reshyproJutihk The lIl of XuOH in pInel of H 2SO j ran nHittble result as a llth H(HY(Pl WIWll til( li-P(l put lthatgtl in lublltl llnalysis or H~O illlP-ius anal)j wn-i uddint(1 thl eharalteliti(s of till liquid with pleeipitated ruhber or resiu in HI~P(ll-ioll n ren1 on the lpNmiddottroshyphotometel m tololinlPtprfollop(1 it lPgnlal lIlll II~ lxplaiHd on pHgP-I (Sl( figs 11 aIlIIl) Tid made it lloible to outain lEPJOshydlHibll tpnlt nntI (onplt1J1(Jttly till JpqnitPIl tlPgJPP of PJPcljoll
IIWIE(TI 1lt COl~101J)
Jtl thp ItJiPl middotxlwlillltnb hefoJ thtmiddot -1l]YIlIt allll pnmiddotdpitallb had lIptll ptoppJly adjutp(l it l fOllll tIuH till llP or a Ploltiw colloid -wll ltIi1)cJ [ttlJmiddotntl- imlIopl tll lmiddotpro]lIibility of the lPlllt JmUkllly ()Ilt 111 U lput lUlU illlihumiddot tOJllPOlUtl tpHd liglyeol teltlut( - llpanlItly IllmiddotlfP(] to lit til I1m t IHflll lImnnmiddott nftlr tlH filial prOIptlllll WtlP dlvPllill1 tlll 11lIlpfit (If thtmiddot [llltlltin lollohl wa Hot 0 natlv I1l(lhmiddotd III rlumiddot Ia- of tmiddot ill tllmiddottJmillaritlu it b [1 hmiddotjlmiddot til IIpoundgt Ir llH1 It liltr ill-llImiddottiT Ina lll ptlPII by it U( in ruhhfl mmly j 11If dtmiddottail fOJ tltt lllllmtlllll If thl plot pet in nlloid ~llntill tltlmiddotlImiddotmiddotlttlatiflll lIOlllllllhtiPI1 are iPllllll page
liTFHFEHliG COIOf
(hi II tht lllail 11111111111 that had til ill -111111 II urklll) om tlH method fot lublJtt tlIlO1 rpir- nlalv~i in plaut llllpll- wa ttl (lilll~ inare tIte (gt1[01 till to tIll ptP-PlHt f xi [aIWIIII- 111 TIlt amount of (olor varip from lUllIt tn -amp ]pplwHlI nlt rhmiddot lt IIf thE Hl(ltllial tllP part of till plllIt -lI11lhmiddot(l tilt hi-tlllY f tlll plaut mtteshyrial ~ub-lltInent to Itlllmiddotnmiddot-rill lliI 1011middotly OrllPI Inlw
In ruhlwr lrtl-i I Iii 1101 au Itmiddot 1Iplll11l by 111[ I--r ratmiddottilt thE -lllll]t with uptoIw or 1middotmiddotlIll-ol - wIdell [llllol- rlll loillriu nutttel autI thtmiddot lpill- Thi- howmiddotvt n(tnll- til lXtla -11gt1 ilt prlJ~edun) In lP-ill ltluay-i nllHufldy tlW[t j 11 1 1IO(PIlln fill the 11shylImya of hlulophyll Hwl rIlI-r middotIOII IHlttlmiddotJ dlH lUtl~ In plltIH withoUt alo aiftIriL till nmiddot ulttrll
111 pllIbIll1l Wi tilmiddotr hId h It-ImiddottHI tht Pltlpll 1 hlitlt lilt tlw tulllWlli tollImiddot uIwltllIIntut -lltUIhorlllllltll 1111 tIll tlettlllliIttwr IIf t 111 lWlrl-Uamiddot of bdt tl11blLlittUhmiddot r [1 tItmiddot preshyj
lipitatifll 1lJ llllllWI atbull 1iI- in III -1nrmiddottIi fHlttalldh nlrillU~ amount rf middotlorilig lIUlttll Iii lhll of ih lltmiddottllllhottohttt~l l~ol()r infrtl Hm II upd 1 rwmiddot tld~middottilmiddottll PlllItlhi~ f it j proYitiltl with tIll lilP--UlY tU(jlIdlllIlml tIltmiddotmiddot lllklllUIlI
EIECTIol OF 1 [EGTH~
-Ptfmiddott ral tracilull ru~lI gtIll fr 1 nllb t ~xtltd 1 lIlt-th vI iobmy1 ketommiddot lWtl rill [ Ixt lttltt ll UttollylaIiIitt1l11I1t~ ~-I itoiu YtHil)u~ typp of ~IHaylllt f i lItmiddot art hraquoil ill fio1ll1 ~l Th~ lp-nlt fill I11oohl uio[1t ttl willlr til tltN- fur rht IUiXtIUt iwliutll
100
22 TECHNICAL BULLErIN 920 U S DEP1
90 bull eo
I shyz 70LLI 0 a LLI a 60
LLI 0 50 z
a ENTIRE 2-MONTH-OLD PLANTS~ 40 b ROOTS AND BRANCHES OF ~ 3-TO 4-YEAR-OLD PLANTSen z WITH LEAVES REMOVED ex 30 a C CURRENT-SEASON GROWTH OF l- )-TO 4-YEAR-OLD PLANTS
20 WITH LEAVES REMOVED
d LEAVES FROM 3-TO 4-VEAR-OLD PLANTS
10 A
0
a Cd 100
b bull
10
80
I-Z 70LLI 0 a LLI 60a
LLI 0 50 z ex I shy 40 ~ en z ltI 30 a I shy
20
10 B
o~__~__~__~~--~--~--~--~----~--~--~ bull350 400 450 500 550 600 650 700 750 BOO 850
WAVE LENGTH lM~)
FJGcm O-Sll((middotlllll tramaniW1IHl (mrpS f(JI (xlmll 11011 n J1ll of jlta)nle tissur ill n 2--m1 Y011111P of (A) Illrthyl ji1I1J1ltsl krtonp 1111(1 (ll) nt(middottQnyla(umiddot tClIc-C(l1osuln a-i
bull
bull
bull
RAPID PHOTOlIElRIC DETEH-UXATroX OF ntBHEIl AXD HEstxs 23
ThE dula Pl(S(l1t(lltl indi(ntp Ihut 101 Illp ulimls llHthyl liohutyl htOlIl (lxtrHts (lI(I r(dolls of Il1Hxi11111III nigtol]gttioll wiH1I all (is-lIb 11 cOllsic1(]((l n1( blhn(11 wn ( ItIl( Its lIO to () I1It~ nlid Ii to Iii mJL
WhllNIS tlw I(gions of 1middottnL(s( light 1lnlllittamp al(l lgtPlW(PIl wan Ipllgtltsnr) to Ii nllt jW) 1I1JL nlld alio Silllill1l 111l1b (n SI(lIlId 101 nc(ton ]altmiddot(fmiddotollp-(llloolp ~ pxt Ill of 11a 1111 t illl TIl( (1101 du( to lolo ill tlw litlltitl a 1Il1 lullll(I tH lPill- hanmiddot bpllI PI(_ ipitated ma he 1((I1((d to fltI ynbhing poillt II ph( illg OJ illshylmiddotJall(( WIWp balld nhm ()) IIIJ1bullbull[1I111 lxjlPIitllll1b Illln -h()1 that Ih( lIIot uilahl( WHYI lHlIJ fOI 1-1 ill 1l11J1l(I HIH11Pill- illllllrsi i-in till IlPighl)()lllll()(l of ~llIl1lt bull
bull UIlIilHlIy of n typhn] lXPllillllllt to )10 l1iP(tiP ((JIlllo( of (ItOIS dul to lOIOl in 1llblnI Hnd Iill xtnumiddott 11(11 IIIIolp t jUl i p1llelll((l ill tub]lL Till llhlllt- 1tpIO]II Hnd ((llll~()h whit-h UI(I ](]Hllilltl n 1I01lllIhb1 01(111 lxt 11111 IIll 1llll)1 nmtp[in I and )(middotills Tid IIlnkl it poiblp nftlI tlIp uplll1tillll or tlll o1PIl( (0 [niH lip 1Iidl1p~ of lI111 11111(( ill lit ll11l1)[1 (llnlIb nlld Ihll
Sl(ll n ol1lliOI with tllP olnl IJllt illiollt HIl Iltlllll llllI (Ill ltllthpl prpipitnnt j Ihll1 nddld OUI ha a lIilPt lP( of till lIiciPlw of WH( lllIgth 7) lUI- ill llilllillatiu (nnl till tll Ixtll1I101l ()lll~
Tuu tmiddot-Elilll IJl flrldillY 11-1111 lrlllI IjfJI til islII 1 1(1 ([rllt IIIIIJIlIr JiIlIt~ if 1Il( Ihll 111111 k til I III Ilrln I 1Intd tf 11111 JiSf fill I I II I tIII Ilf Iilltl 1f1JlIIillII1f I Till 1[ 1 IId 1 (I (middotIt 11111 (I1I1iI1 1lf1IWtlfJlIIllfflr p middottrllhIJ11 II J III 7IImiddotIa 111 111 lilt jJIp 111 wilTII
t~t tnVIli~ ~nn r kn t~ i tmiddot ~~l Jr 1middotmt ltlTt
HmiddotOtt ~I~ lin t I ~ 1 t~~l ~qrmiddotthtmiddotrtwb
Hult-middottltlru t T Hw ullut rHtt~ r II I ~ PH~lllt
A~tmiddottHHjmiddott~rjd rl ~gtllh 1 tn~th~ ~ ~ middotI lt~ b w bull hmiddotth~ 1i~lIhun 1 Ii tnl Illd1 -11lt1(11i lullI lUI tJl ll~ t1~11n( I Ihan1li flfttIJir Ult I Uuhtltt ahuul l(hmiddottHmiddot~t trv r fti HIt lftbyl tlonhUt)1 k_hIl( 2 m~ fmiddotf tuhlHmiddotr In mlth~ llmiddotlf- 1 t r
t r_~ t j
Arhlitlltd ~llIIDHl NcWitn1 ( Ar-(lt()nc~middotttrrtrt ritJJI~ -Iu nllJtl4-middotr
ACtmiddottflnp fmiddotxtrn( ~ T-P511ftf tn mtmiddotth~ 1 ~difmiddotut~ kdn 2 nltt ulruhhtr in Un-tIl lltbu )J~IYt
rUth(Hl~hltlft HhubU
Illlh(I(t tttUtUt hUbtl til J ~jlitl(J Hilllll trtIIImiddotjtl1ll
(UShl I ~tlO wHllolH rulh r (middot1111$0]( J~rru t t )lthyl 15bullbull1middot1101 klll1l
Ili( UHUicbcul ~((i1rUtl ~ulu1iin 1middot lIUIll Ilti lrllltlllt I Ruhhr llt1thuI r1 -1 Irld
ltlt1111Sh 2 nuz f)rruhl~rm nlith~l tu- h f nt nil~middothgt(H] tlrlftmiddot 9lUtirtl middot1 1
rlcltfl( H(l dnllltml it
(IISllhH~rI( Iultruhtr CII05 1v ltTlft I 2 UI~r ublwr In llldh I hlt~1 11) lgtjdvr(llsl~9rlltmiddot middotlmin ~ I~ gt AIHItilltl no IrttipHallr iI
~ Bbnk 10ol m(thyl i~tmiddotut~i kdHn H 1 m1 j~~ l1rH-t lt~tlfltmiddotn sf n it ll HltlMjftr~nol O2~mlJ ~U~1o-ulp ti~tW -xtra~middotl(lt1 ltt 411 ml bull ie f Ct- kft rt t~ tirattJ middott ill r u l1kn ttJt
in metltl isobutyl kNqnf nn~i mljp ur tmiddotmiddot ~oml ~urr tttl i t w ltJj1JH kt 4t 3 nlank 1 mL((l1t~rthmiddot(middot mI mttr~ ~but a kmiddot tmiddotc d 11 ~ gtli~b~ hifIAft- fl~ lL lnti 149
ml8(dlfilll BO bull 02 gm guayule U$Stl(middot xUlClt-l tf(h tft wI n nmiddotmiddotmiddotlgt 1 lznt on tmiddot ~Jt r~1 ~~u~~ H~ iI~ thT
24 l$CHNlQAL BULLETlN l20l S DJltJPT OF AGHl(CLlOHJltJ
In table a is pl(sentc(l such c1il((t edlt1tIHC showing that thc (0101 Ixtrnetccl from guaYIIle tisslIe wit h II(P(OIl( n nd (pl1oso[yc is cll(div(ly sCIe(nec1 out by the s(lp(tion or wnw length )0 miL Oil t1w SI)((IOshyphotonwtpl This tnb]p all-HI ihos thai thl Juhlwl altl(l((1 (nn IJl quall shytitntivcly 1(I(()(Ipltl in tIlt PI(ilIH( or Ih (o]OIplnwPIials and Illsins and tlmt Iuhb(l WtlS nppnlllltly 1I0t (xtltI(((1 110111 11l glll1I1l lisslIt b~ tlHSP SOhlllts Thls( ((suIts ginmiddot (OliIHillg (idJt(( that t Iw IISI of waYl llngth i)ll 1Il) OIl till SppdTophot OIllltPI ii t hl 1101(1 p(oshy(ellule in photolllliTie IlIlalysis of luhhlI OJ l(sin-
SELEGTIO- OF )IOiOCUHO)IAIIC ItIIm ((1111110
On th( basis of th( IPHIlb shoWIl in tabl(l 1 al hlllpls (1( IIln(lp to SPCtl lC the PIO]Wl 11101lO(lIOl1ln til Ii ltlJ ((lIllIJi nIl ions 10 llIiOlS (oIOlimet(Is 111(gt 7W-Ill~ filtpl flllnhwd 101 til( I1~lI1l photoshyplpct1i( (o]oriJl1ltll fol which Ill( (hlll(IlIiitit~ oj t hl Ilda he light ilUIlBlIIhiSioll (t) elll nn -hO11 ill fig1lle 10 iws satlsfa(lolY IPshysultl 111( iiO-mL HitlI olllhintioll 101 whkh ttp (middotIatinmiddot light tlnnsmission (ullmiddotis a 1-0 showlI ill figllll (I is -nthdnlto1 hut this is not stnlHlnld NtllipmPlli
Up to fhl PlPHllt lIS(middotflll pound11((1 (ulllbinntions jn lltl iOO-I11L Iunge hayc nol bllll SlClIlld 101 lhp Klpt 1-1I1l1I11PISOIl (olOlinwtll bu fnltlwl nttCl1lpti 1( )(illg IlIHd
TJIpound OF ST~lmW AFTEH HIIJ1EII Oil HHSIS rlll~CIIITTI(J
~ considl1ltiol1 of ttp lillll of Inlllling af((1 plpeipital ion of 111gt)(1
01 l(sinSTlOIll ollltionis impoltant J(jl~ thC1HI(Plltngp of light IInIlSshy
11 rshy10 f shy
09 f shy ~750 Mil- DOMINANTI
~ 08 cshy I WAVE LENGTH z
I III III i O7 - I III
~06 - 05 shyw
a
Igti= 04 - 720 Mp DOMINANT ct WAVE LENGTH- ~ 03shy
02 f shy
01 t shy 1)O~~~gt~- J 600 700 800 900
WAVE LENGTH (Mp
bull
bull
bullFIGlRt IO- COJllPIUlItiw ~IW(middottltll tlnIlRlllii-lion (II (IllP( 101 1i11(1 olllhinulloll
with dominllnl Il(lllllgths at 720 and 7iO lUi
bull
bull
bull
HAPlD PHQTQlfE1IUC JjETER~lINATION OF Rnmrm AND HEtiINi 25
mitted (spertrophotoll1eleL lCuding-) Ol light (1 (tClcrl (phOlOshyJluol01l1et(L lcndillg~) i~ StlhjNl to (hangl
]fjt~l1le 11 and l~ show that ill til( (asc ot tJaugtIllitteltllight llJHC th~ (x[llliHlllIlnl (oIHlitiOllS tllpl j lilst n dtlln-e ill Pll~(lltngl or UllllslllittnlH( follrnY(l by It ptJiml of lClntin stability with only sliuht (1111 tHn- a f(Pl a lIt1ll1btJ of minutes The light t UIllllitblllll t l(1 ill(Iln~(s This lIIay IJP llllllJltlli7P(ll1 ffl II ow 1Ilt )( f(( darI oliIII tIIlIlNlIlitt(IIIlfJIIlh (iditilIiid Ilil1 pllIipintnl )uoshyIn Of ( 8inx in (~f1( I~iUII i~ Ild stahl I 11 itlll If 1inl nh prlshyilli(ioll of 11l1d(1 II IJIX f) jllIli II (fJJltfiIIlilty slllMI IIriot 1) IIIPldUnl1i tll(I1I rllltltilJl oj tJi~ Jlt jiot IUN ilUf Jxl1 will tIt( tOWI IItlllilil I 1llIlllblJIol I ill I~11l11111 d ill till ifjuids JjOI scnttplltl light 011 till phololltHJIOIl1lttl till dilPCt ion 01 elangl b tlw IPrfIi (If that illrli(atPll rOl tlulll1Jittp(lliuht It Itlll b( llluliJr I-(Pll that if l(middotndlnJ- IIIP mad n itl I t lIP ~()ll1d()lb lpalll this pllioJ of nmiddotlatirp tuigtility tllP llLot tIOllt thi Olll(P (nil bl IPdUCld to tIl lltini III 11 Ill TIll l~adiltg (illH~ bbll Oil tlHl datn rUl lublwls and llsinlt Illl ginll ill tnhh
50 r----------------------------------------------- f shyZ
~ 40 ~----~W~A~V~E~LE~N~G~T~H~7~5~0~M~P~~~~ ~ --------------------=-=-= ~ 30 f- WAVE LENGTH 540 M~ _z _____ ___ -=- __ _ ~ ------shyt ~_=---=-=--I GUAYULEIII 20 -Z HEVEA ltt II KOK-SAGHYZ f shy
4 6 8 10 12 14 (6 18 20 22 24 26 28 30 STANDING TIME (MINUTES)
FIlirtn 11 Emmiddot of wav hll~rh Il li~ltr tlall~lIIit1alHl aftI IUIlItHt -Imlli lug 111m for guaynh llmiddotn 011111 middotiolIlJh~z 1111111 llijlitul1 flolll 1lHlh~ll1Jllryl k11II11l ~(lilltlll h~ lwitlitll 111Inu1 111l~1It1 2)1111 o1U11111 (Helillins on (illllun tlunhll IlIIJlllw]ntllW111 lutl(I[lholtllllltlt with ijUjt Wlnl IHI Ilf1 I
11 EFFEGT OF Hbli 1 -()JXT10~
Tilt lnblwl ~()h(llh pxtnl( till IPillgt ubo It 1m nllu1- bellt -~atea thut ~lll 11-111- tUP olnbhmiddot ill middottIIlIlOl ~1It tlWIIJI( my U)t PIl (tlIHatcl WIth tl1l lullh(t I tahle lJ 1hln 1- -1111 tIll (llllstlOll of nny p()~iblt tITptt of XtIIl11 diflp]lws ill ((JlllPllttUliollS of 1l-in lil lolutioll alollJ with till 1lIltbpl TIU data ill wbh +ho on tIl( hn~is of (olorilllPill ladillU thaI tll( IIUOIl1t of lnbbll Plllipirntld 110111 Ilwthyl olnlld kptOlll olntioll IJ 1li-jHlllnt 1l)04 in 1-llltlIllt ethallol)- not amlll hy thl llllNlI(l of llvin aU1ouut of llins inolution bull
-----
26 rECHNICAL BULLEfiN 920 U S DEPl OF AGRICULlUHE
100
90
80(I) C)
z Ci 70 UI a 0 60 a ~ UI ~ 500 ~ 0 I Il 40
30
A 20
0
100
90
(I) 80 C)
z Ci 70 UI a 0
60a ~ UI E 0 50 ~ 0 I Il
4-0
30
B 20
0
--
--shy ---shy---
2 4 6 6 10 12 14 16
---shy= ~ ~ shy
-
2
025 05
10
15
20
25 -30
35 40
SO
-60
=70 80
16 20 2224 26 26 30
OS
- 10
IS
20
2S
30
35 40
-50
-60 -70 -80
bull MGPE 25-ML
VOLUME
bull
MGPER 25-ML VOLUME
Florm 12-EtTld (If till1l or Slllldill~ 011 light transmittallce (01 (A) gUllyulc lnUIl(I plccipitllitd frOIll llltt h~l isobutyl Ielollt solution Ily neidilic(l ethanul bull null (B) gUllyule ll~illii pre(ipitated flom aeltoll~lllcetOlll-Cl])osolY( 3-7 solushy11011 by H(illilip(i l1U (HPlldillg~ nt -lIlillult Ifllpluls 011 Evelyn photoelectric colorimellr with jU-lllp tlllll alit U-1I11 npN(lle spp also table 2)
bull
bull
RAPID PI-IOlOMEllUC DElEnMINAlION OF RUBBER AND RESINS 27
TADIbullbull ] 4-ReZation of amiddotmount of middottbber pleeipitate(Z Oln metltlIL isobutyl ketone 80lutions by OS-pereent H 2SO in 95-pere(lIIt ethanol to umollnt of resin8 udde(l U8 indivute(Z by colorimetrio readinU8
(Rubber ami resins cnlculntcd on bnsis of amounts in 5middotml ullquuts of extract from 02 gm of tissue in a 2fllll olumo( bull
Hubucl r~cocrell whcll rcsins nddcd as IndIcated Htbbor al1dcd (pllcollt) ---shy
__________bull_________ ~_12rpcrc~15011crccllt 7511crccnt IOOpcrcent
PerCtllt ercellt Percellt Percellt Percent o o o o o) 50 250 263 252 25000 500 500 500 500 700 750 750 751 749
1200 1250 1250 1250 1250
EXTRACTION TEMPEHATURE AND TIME
Typical experiments to detllmine the time required to secure maxishymum extmction of rubber und ltsills at 115deg U Ilre sUlIlmarized in figule 13 the solvents used-methyl isobutyl ketone for rubber anrl Ilcetonylacetone-cellosolve 3-7 for resins extraction-are very eflicicnt since under the conditions indicttted maximum values were secured after 30 minutes of ext1llction The most eflicient liquid for the bath (lig 1) used in extrtlcting rubber or resins is ~ high-grade cylinder oil (S A E ~O) The sand bath and such liquids as glycerol have proved unsatisfactory
RUBBER AND RESINS STANDARDS
According to the National BULeau of Standards 1-_ lhclc Is no gellcrnlly recoglllz(d standard lIIutcrlul [ior II rubber standard] The rubber hydroCllrbon ill llifferent samples of conmlcrciul smoked sheet or pale crepe from heclI pluntlltions nries from l~ 10 04 llercent of the totul nutletmiddot the most 11Ioruble conditions Of preparation
McPherson () has described a procedure for the pLeparation of pure heve~ (Hevea brasiliensis (H B K) MueH Arg) rubber from crude rubber or latex In the absence howevcr of ~ generally recogshyn12ed stalldard for rubber hydlQcllrbon [caoutchouc (CnHUs) xJ the standard adopted was that of the relnthely pure product secured from gunyule tissue txtractiotl nccording to the Spence-CaldweU method (5) or the motlified PIOCCdUlU of Hohnes lind Haasis (p 2) The details for constructing the calibration CULes are given on page 10 Standard rubber samples apparenl-]y can be stored for a long timc under the conditions des(libed on page 10 The duplicate colorimetric lendings for glULyule rubber newly extracted by the modified SpenceshyCaldwell method were ()J2 ench as compared with US) each for the sample extracted by the same method but stored 1 years In each case colorimeter rcadinllS were made on mixtures containing 2 mg of rubber in It 25-1111 Yolume
The selection of tt suitable standurd for guayule resins presents some dilliculties Tll(~ acetone extract of gUllyult estimated on (l gravishymetric busis~ for instance proved to be variable depending on the type of tissue sampled or season of sumpling because such fractions as
COllllllunlcntion dul(lt1 Octohtr 22 11H3
28 QECHNICAL BULLEQIN 920 U S DEPT OF AGRICTTIIlURE
16~==========================115 shy
14 bulli= 13 z ~ 12
ffi II Q
10 c w 9a w
8gto () 7w a
6a w
5en III ) 4 a
3
2
A 00 5 10 20 30 60 90
14~------------------------------------------- bull13
i= 12 z w II ()
a 10 w Q
9 c w 8 a w 7gt o () 6 w a 5 If)
z 4 If)
w 3 a
2
o+B~~__~__~____________~__________~ 5 10 20 30 60 90
HEATING TIME (111 NUTES)
lllGUltE 13-lDffect of time o( lICntillg O2-gm samples of gunynle tissue with solYlIt nt llfio C on lo(OVl)ry of lllhlJer alld 1Isim Lt HlIhblL extracted with methyl isohntyllwtone B resins Cxtll1cted with aCftonyla(etonc-cellosolve 3-7 bull
chlorophyll are weighed along with the resins in the acetone extruct but are not estimated by the present photometric method (fig 0) 1he use of a diffeJent stanclttrd waS therefore indicated
bull
bull
bull
RAPID PHOTOMETRIC DETERMINATION OF HUBBIm AND HESINS 29
The resins standard selected is based on n relatively pure source of resins the rcsinous exudnte 011 the stems of guuyule plants IJldimishynary expeliments with the resi nouS cxuclate from diffcrellt gllayu Ie strains of various ages indicatc nHlt there is little YaLiation in this subshystance on the basis of Colorimct(r readings 011 2-mg aliqllots of 01shypercent solution in It 2i-ml volume (tabl( li) Expelilll(lnts have shown that the air-dried (xuclate contains 3RtOH p(Ic(nt of -volatile matter This material is l(latiyt~ly stablp ill (OlllpoBition and is npshypurpntly on ly slight ly hygroBcopic as shoWIl ill Ia bl(1 1 Tlrp Ipsinolls exudate may be jJleplpd in two wayi-i fl liSP as a stallClHld-(l) the clpan exudate is clripd iol Ghouls at ()1deg C at W indlPs of a(lIum Hnd aftclbCinOglOund ill a molfalis 1)I(spI((I intn airtight COllilinel OL
(2) tllP Cx7lclate is clissolllt1 ill a(lhllll and filtplpd PlactieaJlyall of the acetm1l is thpn lYapolntwl olt OPI a stlam or atCt hath and Ow residue is dripd ground an(( PI(sPIld as ill tllp fin lllethocl Tlwse two prepalHtlolls a1( (ompalpd in ta hlp ) 111( (((tails fOl ~t()lil1g the resins standald and (onstlllcting the calibration CUITPS alc given Oil page ]2
lAIIIg fi-CUIIIllrsoi (lJ lIr-dr(1I IIIIi 1((11 II II-()I-tr((l l(sil~ 11111111(8 of I II 1111Ie
[Colorimetric rrndill~s 011 1~I11 phulll(Iclrie eolorillJct[lr with i~()middotmll (100- to iiOIIIIl) fillcr [lnd 5-1111 lIperture preeipitantl part ofO5middotPIrctllt 10 to 5 paris of IIOj
nupliclllc(oloritwt([
nIl(lin~s (hIlSlcAg~ ofSlmillXo JrNliltlCllt of fPsiJI$ L1Xtlrlntp on 2 IIIg ofplanls fllsins (XIHIIlt~Jwr 25-1111 vol
tII1(1) 1
leflTs Various _ bull ____ bullbullbullbull 3-9 Colll)Josiltrlairmiddotltlricfl bullbullbull nf)2 002
])0____ bullbullbull _bull __ _ bullbull ~-l Composilld (ri d at n5 C in aUmiddotimh lWUUllJ for l (jOuj(ja hours])0______ bullbullbull __ bull ___ bull 3-0 COJIlpositld disso]NI in neptolll f1l1erNl fl(lf()ll( GGO i(jO (Ivaporntld olT OV(1r Stpl1l11 halh TesidlH drl(ld I1t fi5deg ( ill anmiddotinch VIl(Unlll for 0 houlS bull
middot106 __ bullbull _ Jir~c1rild_~_~_ _~_ ~_~ _ ~ ____ _ __ _ OUu GOifina_~ ~ _ ~~_~ ___ _ _fln~ ~~ ~ ___ ~ __ 6(imiddotI tiliA H)[_ ltlu bullbull i18 tisSflOabullbullbullbull__ bullbullbullbullbullbullbullbull lt10bullbullbull _ tillO llitO406__ bullbull __ bullbull __ bull __ __ lt10_ Utl2 fon591_ fo__ bull liGa oOa 406bullbull _ __ lt10bullbullbull_ li5S OM
j Ph( vnluls in Uw Inst COIUIIlIl indieatp thnt gunyulp fesinous (IIHlnt( wlwtlwr dfircl hi Yn(tlLJ1l1 wilh L~ perc(nt loss of volntllt wutl pr or tWl c1rild giVPd npproxil1lnh1ly t Iw snllw colorinwtCr rNHiing- 011 till busis of aliquot~ cOlllniuiug 2 IJI~ of flsillS lXIHlntp l)tIf 25-mI volultl( Ihil- illdicate~ thl11 Uw UITW IJ1flS~ of olnshytile mntl(f prt~(iJlitnt(d gins npproxilllntlly Uw $1II1l (oiOfirnl1tlf ftudiTlJs ns tho ftsidtw A pnlill1jllaf~middot (XIlltrinllnt indicutls thlli th VUllltill muller l(lIlSists of thl Ilrplne oil fmcl ion I5-(1Il gtnplls or rlsitlOtlS (lxudntll gnvll by stPll1U distillation nn Uefllgl of 011111 of jl(lfPlIW oil with npproximHte tilllsity (If OHIi lind lhus rrprlsll1ll( IlPIJroximllt(I~ 01 Jerccllt Of t he original weight 1hls lllrClnlage complrcs wllh 38 llltrC(ntlost by drvinI( in IICllnllJ
aSplusmnUH perceilt or orlginlll weightlosl
The wailnble illfolJllntioll on tlH (ow-JitlPllts of the gunYllle r(~shyillOllS exudate alld tl1( HeetOlIP ext act of gaylp ti~slw is sllIllmarized in this paragraph lYalttI (u) alld also Hangcn-Slllit lind his coworkshyers 16 reported that 20 percent of the resinolls exudate from gUltyulc stems is parthenyl cinnamaie (CHuOH=CHC020 11JI2r) Steam disshy
15 (OIlIJIIIIUicatioll flom A T Haai(II~l11it llId (0011(11 Calif0111 ill Tnfiitnte of Tccllllology Past(IlIJI Jhps( wOlken al Htud~ing the COTlHlitlllllts of the acetone extract and other conlltituellis of guuyule
30 TECHNICAL BULLETIN 920 U S DEPT OF AGRICULTURE
tillation of similar resinous exudate in the writers laborntory has yielded approximately 4 percent of the whole as the telmiddotpene oir fracshytion Haagen-Smit and his eoorktrs nportec1 thttt about 25 percent of the acetone extract from guayule branches is parthenyl cinnamate and 6 percent of the bark (ltortpamp-phlotm) extraet is parthenyl cinshynamate These workers fm-thcI reported that 25 lwletnt of the nc(shytone extract frolll bLllllches is a compound with the tlI1pilicaL formula CBoH400a 1 percent is a compound llwltillg at 2P to 2T5deg C and 1 percent of the extract from the ]eav(s is tl (olllpoulld nwlting at 100
to 1710 1Valtei (6) reported that 3 to -l perc(nt of the tI(eton( txtract
of leaves and flowering StPIllS of guayulc eonsists of waxlike substances soluble in olgallic soln~nts but insoluble in at(l and (on(ent1llted H 2S04 The flactions mentioned on the basis of (onHLTutle esti shymates of amoullts actually isolated tlecoullted for about H ptIcent of the totalncetollt~ so]ubles extracttd from tll( guuYllle 11 rub The other constituents ltlilaill to be i(](ntifi(d
RUBBER AND RESINS CALIBHATION CVHES
Typical culibndioll Clllves iol Iuhbpl and I(sins bas(d 011 (ldtLminttshytions made nccoLdillg to the plocCdmC outlin(d 011 pages middotb to 1G arc shown in figulPS 5 and 1+ The spCdlopliotoll1lttL en (OIOIjlllctCI readings are plottCd on s(lIlilogalitllllliC pappi ag-ail1st (Il 11IbblI (011shy
100 ~ 90
80 ~ 70 ~
z 1amp1 0 II 1amp1 IL
1amp1 0 Z
60
50
40 ~ltI 30 ~ en z ~ ltI II ~ 20 C) ~ oJ
10 o 2 3 4 5 6 7 8 9 10
RU8BER IN 25-ML VOLUME (MG)
bull
bull
bull FI(lURE 14--Ctlihration curve fotmiddot gllftYlIlc lubb01 (Hct(lings Oil COIPIIHlII tlOl1hl(
monochromator SlCClrophotolllet(r with 7fiO-11IL Illtel alld Hllp Wll ( IHlll()
bull
bull
bull
RAPID PHOTOMETRIC DETE~MINATION OF RUBBER AND RESINS 3]
centrations From a casual inspection of these CUlTes it would appeltr that Beers law does not hold Actual tests indicitted that Beers law was applicable only within a narrow range in the upper portion of the curves The analyticlil results on the basis of photornetric readings nre therefore calculated by direct reference to calibration curves or from reference tables of equivalent values bllscd on the cnlibllltion curves
Calibration curves for kok-saghyz alld heyea lI11tulltl rubbers and Buna S (GR-S Chem Gum IV Goodyear) and butyl (GR-I Standshyard Oil Co Protoc) sYJlthetic rubbers are hOWllil1 figure 15 The samples of kok-saghyz rubber were furnished by the Diyision of Rubshy
100
90 ~I) ()
z 0
1amp1 a
~ a
80
70
60
s 1amp1 ~ ~ 0 ~ KOj-SAGHYZ 0 l Il
50
HEVEA~ ~
40
100
90
~ 0 80z Q 70a Co)
a 60 ~ 0 0 x 50Il
40 ~----~~----~------~------~------~--~ o 2 3 4 5
RUBBER IN 25-ML VOLUME(MG)
FmUIlE 15-CaJiblation curves fOl kok-snghyz h(YCII Bunn S lind butyl rubb~ls (Readings on gy((yn photoelectric colorimeter with i20-lIIp filtpl and 6-ml aperture)
32 TECHNICAl BUIJLETIN [)20) 1 S DEP1 OF AGrnCUIlfURE
Iwt Plant JIl(I~t ignlioll of thi BlII(un and (1( l))(parcd according to 11( SPltI1((-Culd (]] (6) PIO(((lllll Hlpt pal( CLPPe was (xtmch(L with acetone blI()Ieit W 1I(gt(11l a ttnlldal(l
SEXSlllVllY Ol~ llETJIonS
By lip pIO((l(II11P olltlillP(l 011 ]Hlg( +n Iowa (lOOl IIIg (11 1111i(l0shygmm (gHlllllla) of 1hblI ill a 2)1111 yoltll1ll (all )(gt dltpltld Oil tltl Col(man (lohlP mOIlWhlOl1lHlOl l-I)((t 101 l1lOt 0111 ci( I ill1ilnlly 001 mg of Iublwr ill a 2J-1ll1 n]ulllP Illay bl Ilad Oil till EnI)1I photoshyllectlie (O]oLillllt(I Thll ya lllll- 011 tilt IHl-i- (J I (xl ad iOI1 fmlll 02 gill of til-lI tH(JI(lillg to tllP -lllndal(l jll()(pdull 1(PIPStlIt IlO()2J tlnd 002) P(IT(lIt of llIbl1ll IPI)(((inly bull1t1lollgh -lI1t low allils can be d((d(middot(1 il lIoullt1 Ill IPtllizpd thnt till PIIOl ill PlI(Plltng( or tll( al110unt dltlIllIilll(J i ltlatlpl high ill tili PIY lo Itlllgl 111 aetllllllladie(middot Ill( lopl lillliL 111)(1(1 lIw (ollllil ions of tlil ]lI()(lltlIIIl u ol1tlinpd ipt at l11 11I1 or 1111gt11(1 illt i-1ll1 Ollllll IlPIPltPlltillg 01 p(gtl(pnt of JllUiJtL un tlll 1Hli or (xlla ion rlOI11 II rlll of tisSIll
EIlIlOH COSIIlIHIIO
In Oldpl to H(IIp ill )1lHtPltt pl((iioll illlpIi1I- it i lH((SSHI to slnlldHIdiz(i rigidly 111( Pl()((dlll( 0 illdi(ntpd Oil pnglt- - to J( If lids i dOlH tlip lXIHlinwnlal PIIll is t(middotdllld 10 n ndninlllill
Illlt pl(iioll of (hI ]lIPPllt 1IHllwd Oil til basi of ]llllP llIllJt1 alld Ipsinssollltions call hI jlldgl(J 110111 figllll Hi lileh lio- til HPIlIgl d(intioll oft -illgIP lI1lnSIlIlIIIlnt in lHi((lltagl of Ill( alllOllllt 01 Illhshy1)() 01 lpsins d((PI1I1 iJlld TIl( (1101 PlI(Plltaglt H1( gi (1 101 OJ) to
RUBBER IN 25-ML VOLUMEMG) 004 01 02 03 04
i= I I IZCtOW
fbA ICtU CtCt WW a
01 02 03 04 05 06 07 08 09 100 = RUBBER (PERCENT)
RUBBER IN 25-ML VOLUME (MG) 10 20 30
~ I CtZ
bBOw Ctu CtCt Ww o I~
010 50 100 150 200 250 RUBBER (PERCENT)
RESINS IN 25-ML VOLUME(MG) 10__ __3-0_ 40 50 60 70 60 90 100--_-- 2_-0
Ct~ -r- 1 I OZ
WCt UCt b C wCtW
a o I I 150 250
RESINS (PERCENT) o 10 50 100 200
bllI 1tI W-Yllnl dtd1 ioll I I 11l1 11IlI11 1(111(11 1 III Plll- IlIIIlol1 01 IIim~
bull
bull
bull solution Il basis J o golH of tiSSII (JlILCl-nt (11(11) for (~I) (l)1 til O 1I1
of luhllpl lin 1 III I (I Ill of lUhlJPl nllll laquo I J to 111 nlg of IlSlllgt (Itllillgs on ]iYllyu pllolwh-llrk CO[IJlilll(-(PI with nOHIP Iiltlr lIntl U-lIll allcrture)
RAPID PHOTOlJElRIC DELEHlllNAllON Cn HUBBER AND H1~SINS 33
10 mg of rubber anel1 to 10 mg of resins in a gJ-m1 yolumC For
bull
bull
bull
comparative ptuposes the leslllts arc also calculated on the basis oJvershycentage rubber OL tltsills in 02 gllI of tissul As WOlllL be expcet(d the error increases sOIlHgthlf for 1(lali nmiddotly low COlHell t1llf iOlls oj rllbbeL or resins The curves in figure 1(j s1l0 that ill til(gt Illlge Ol to 10 pCrshyeent of lubber the elTOI rangts Jroll1 abollt Ll to II) ]IlC(lIt abo(~ this mlllc tIlt (ITOl d(((ts(s to (ollsidlItbly ltmiddotss (han 1 1lICPllt of tlH mllollnt ltl((Lmill(d Hil1lilally in tlH (lISl of l(sins analysis (fig 10) the ltLTor is (onsit1eIubly INS than 1 PlLllnt ill (he lallgp of 11 t~) ~() penPII t
In nil ([lSl of lllhblI alld (sins lx(Inltpd tIOIl1 (issups Ol addcltl to tisslle lxtlads (s(( tabhmiddots (i H) illyolillg ll01P o(lllntiolls the eLI01
is hig]wl thun that indilHtld in figllll ((j Im pUIl Ill )])p I tllllllsins solutlOII
COlllUCIIOXFOH IXSOLl-IlLl~ Ilgsqgt(Jg
111 th( Jllo(pdulP ollllillPd 011 paw I till illsolllhll isSII Ipidll( tflpl (xttlw(ioll is (Ptill tlw lIask l(lll till xtlct i l1wdp up to yoltlllH It is not rOllPllipnt (0 IPt()PI qWlIltitati(Ir III(lw[olH a 11(1 pllooll extlnlfs of guuyull I is-lll alll thl1l main t11l111 up (0 YOIUllllmiddot bpCaUHI sllch all additiollal stltp wottld]) tillll-C(JllS11ll1illg Th( Iogiea nll(gtIshynntin is to mnkp tltl lXtlUCt Llld Ipsidup lip to OllillH in till original flask andi llPSStllY 10 llwlno tl OIIpdioll wlHIl (allIlnting [hc llshy
Hults f(JI [hl oll111lC displupd hy till ins()lllbh llsidll( III it l)picat (IXpednHllt (ollsisting of Jhp lppJiea(iolls if was Iollnd llftt at ~iiO ( 02 gill 01 Iuhhll pillS IPill-fl(( lisslI(gt (lollpdll fot llwistUlC ou basis of dlyillp ut lOW 101 ) llOlll-j (lbp(ld only t~ llllUll voiul11P of OOk7D~- OO(lOO(i Ill of lllthyl bolnl(yl 1lIOll( (lplhlli(al-t(Tnltle sp gl () Ii I ll(Hli (j at ~)) -gtitllP tl1(gt 1It101111( () r t is-lIl xt Iadld j sl1lall til( PlIOI dul to Ill(gt insoll1blp Ip~idll is slllall III [0111 ill( wOtk it (all lJp diIpgal(ll(l
]hcon~lIY OF HllIllgl AiO HESIS AIH)gl) TO EXTlIACI OP
GlYlLE TISSlg
Tnl)ll G L(IHpslntillp (ypi(nl llld(~ SllOS (hat all a plngl of HIOK PlI((nt ot lltl pltl( Ilhl)(l acldpd to tllP Itll h iolJut1 InmiddottcJllP xhnet
of guayulp tiSI1( WllS 1l((PllIl Tlli nllintioll flOlll (olllplpU I((OYshy
PIY i within flll pxp(IiIlHuttllIIOI ~illli]llly fnbll Ii llows thn 1111 llYlIUgl of 1O(1~ ])(I(Pllt of gllllYllII 1(-i1l- add(d to II( (pllosol( (xshytrae of IUllY]l t i~HI Is 1l(oPIPI
THl~ (~ Hf (Off Ill of 1111)( J OJ I~il~ lItfI(( In ~(JI1IJk~ Ilf (111 [lI1Il fI2 lIII
0 tlUfllllit i~~I1
Instrument
---- ----~---- bull shy 1(1
Colemun ruono~ltrOUlllt()r 2t) II sJl~ctroJlhOL()lIIeter with 2tJ I iflllllI wnclength Fetting 21 II nntl 0-1111 WU HI hUJl(L _ L U
Ill 7Evolyn photo~lcclrie (olor JU [ imctcr with iO-llIl filler IV (I
H1 0 t I I
llImiddot lUn WII 1011 HIO Wn mil lUulon
10 JIg1111 IUI ml lUl anh Io aLn 111)_I ) III li lU It 2) deg wn2SU DD
Irl JIll II IIr II US II
1110(1 lULa lUI IlK) IJ WU
I( llI Htl tNI 1(111 2tlNI HI 0 221) lllil t2S 0 1~ 10 1~13
In (I 2117 I
10U 1l(J ~ 4 _H_j ___
9middotJIlJ5 10115 10 00 lUU5 flUU 4li (tl03 9(11)
leIlKl 1l~)5 lOOU l1KIr JOIS un 003 OIl Ii
34 lECHNlCAL BULLErIN 920 U S DEPT OF AGRICULlURE
COMPARISON OF PHOTOMETRIC A1D MODJIoIED SPENCE-CALDWfLL METHODS OF RUBBER ANALYSIS
Guayule samples were analyzed by the photQ111etIic method and by bull the modified Spenc(gt-Cnldwell mcthod The values in table 7 represhyselltativ(I of typical results indieate It -atisfactory dcglpe of conformshyjty between the two methods in thl range of tiSSlHH with llHHC than OJ) percent of rubbtImiddot On the bnsis of the amounts determimd the results in this runge for the plmiddotts(nt lIlcthod ayernge apploxinHltely j percent highcr
~LAIII~ 7-(oIllJl(i~on of lltlllrIic (IIri mOtllinl SJl(II(r-(ulri-wall IIIrtlwrl~ of rlrrlIIillillfl 11)1)(1 COIIrll of UI(III
1 Flowers frllm amiddotmonth-oltl nursery plants
YAIIIATJO- OF SIli(LE DETEnt1NATIONS Fnoll TnEIIllIEAN
Rllbbel (Uall8i8-Thc plcCision of thc pLcsent method when gunyule tissues Hr( nnnlyz((1 for rubber may be j udg(d flom I Ill datil presentcd in table H TIl(se dahl -how that thl pplCPlltag( uriation of single determinatiom from nwan yullles with low standllrd enolS ranges from less than 1 to 4 p(gtrlent
R(8in~ wWlsi-r-s lndi(a((1 011 page ~j he INntlts s((uled hy the present phoolllttric nsins llHt hod are not tliltly (olllpalable with those of the grtLVimetri( ncetol1l-cxtlt1(tioll II1etho(l Thjs made it necesSllry to selc(t another lalibllltion staudud-tlll Ipsinous exullate from gullyule shrub-thut gies relatively COllstlllt photometric readshyings (table 5) The resin (olltents of guayule roots branchcs or leavcs usually ran(~e from about) to 1-1middot pelcellt The ple(ision of the present methotf WhCll gUHyule thslllS lIe analyzed for reins may be judged from the datalHmiddotpscllted ill table 9 1h(se data show that the p(lcelltage variatiun of sillgle lhmiddott(Lminntions iLO11 meun ynlnes with low standard NTOrs rangcs from about 05 to 4 percent
bull
bull
bull
bull
bull
RAPID PHOTOMETHIC DElEruIINAlION OJ RUBBEH AND HESINS 35
IAIILE 8-luriation inclieute rubller (mallSM of [1wIIle tissue bll thc 1111O0Illclc metwII
Vnrlntlon~Ilbher I (rom mean
ierCtnl Percelll ~OU -22 ~ 25 +27 ~ 20 +18 ~UO -22---------1_______ 51110 0G6 bullbullbullbullbullbull _bullbull
10 ro ----=ii41075 -01 1000 +11 1010 +13
rlln HI itil 1l9~ 1_ ___ =-~~~
115511 ~ US -111 III II 1575 -13 115 b tiS -I a 111 h WlU +22IIM-(middot bull 11K -1Ja Illi c 1000 +03 1J5H1 W +l)7 ll1imiddot tl 1575 -13
Mcnn 15951 131
1102-11 21fJ() +21l102-h _ ~~)SO -17 1102-c bullbull 21CO +21n02middotd ~OIiO -26
2 r~plusmn Il~ 21151 261 I -~-------bull---__ _~~_~______l-___--_
1 lhe$ 1111($ I1n (or SlIlIIllltS Stpnnltplr PHrilClld IIrtlrdlng 10 1hr prollIlIlr( OIiIIiIl(o(I on Imgt$ 4 to IC ~tcond nUlI1 hlr r(J)[ltnts stl1ndnnl llrrot of tilt 1I1(1111
1_1l1~ n-J(lri(iot in relli(Upound rpoundsins (lllalIsfs of VIOJII( lixsue b1 the lhomillric lII(lloli
-- ---~--- - __-------- shybull I I I I Varlgttton
_________~___ ~~lu_n_Jl_Q_~~~_____ ______I__~_o~S_J frOID lDean
Percent Percentgt458-1 ~65 +41IWtl-li 130 -a2Hli8c aliO +26S41i8-d bull 130 -32
1(-011 34I10Olifgt __ bullbull __ ~--====
li-9~2n 881) -06 li-9~2-b Si5 o ~HH2middot(middot S i5 -6$-H2middotd 000 +1
8851 054
O i5 +6 9 i5 +6 950 -20 U75 +6
H-liG3o-n bull -1 n-li6~b bull __ _ -IH-IWH +4H-l61511 bull -1
1tmiddottlU
62~-lI __ 62~-b ij24-( bull OH-Ji
(-Ull
I rll(St oluls nre tor separately ~xlrflCled SllllllllCS IlctOrdlug lO procedure outllned ou pages 4 to 10 i Secoud number r~prtgeulS stulldMd error of lIe menn
36 TECHNICAL BULLETIN 920 t ~ DEPT OF A(]RICCLTCRE
ReUUER A~ALYSrS I~ CRCOE-RcuUER PROOCCTS
Sew rapid photometric m(lthod~fol the ddellllinttion of rubber and reii Hi ill uaYllp ti--ut htp lllell pIPHnl pd oil pag( ~l to In A brief H1111111tlY of It similar rnpid llHthod fm 1I1hb~rllnltlysis of u1lulcanizNl tlIldp lubbll pl(Hlmtlt whielt i~ bn-(tldo on the prill o
ciples dehtilcd tlllLe follows Duplltate nt-gm sllmph of the finely cliyiliNl IlInttlitiup wlirllll out [~ei-()l (all hl lIf((tinmiddotjv INd to lt1iyidl till alllpl) TIll kltolll-olubll portion of till )111(11( tlrc di-olved a- indh-Htpd fot thmiddot lllnkill~ of -tlllHlunlluhhll olutiou Oil Pt 1II hut tIl IUlIp Hn lIn l-fplImiddotd 10 lHI-ml rolllllltti( fln-k antil1ltld(lup to Olllll1l The bnlulUp or till JllO(ldllll i- thatutlilllll on paWs -1- 1 IHI Ii 111( 1(111 1- nIP IXPIP--pd nil til IHi or Iw oligiJla w(lullt of I Ill (I11l1p-I1l11Ilt1 1)(0(11(1
Hupitl PlllimiPJojgtiWllllllllh llIltllOd~ fOJ Ihl llPtlmiddotminntion of ImiddotUlJbll tlnd 1(-illo- ill -111111 Illllph of gutlYllll tiUl IIll dl-eli)ed 111() IlltlY d~o Ill nltlI1lld fOl III Iwl Illhlwl- and l~iJlmiddotb(lLiJlg plant TIllt l[Olllhup hns nlo b(l1l ntuptpl fot IIH lltlIll1illtltioll of lllhbpl ill 11lHhrublwl Pl(Jdlld~ HIIl 1111 hI ndaptld JoJ IIll ann lysis of ynt1J(gt( ic lllbbl[- The llllthmb HIP 1gtn(11 fill tIll fol1owill plimiph- III Grinding
tIll PIOPlly driPl t i~lIl 01 Ul tillg tIll pnHhHt to tll l((lllilllllh~lel of filWlH-- til plllllit qIHlIllilnth( lXIIHtioll 01 IIlbhlI 01 1(--IJl- () llsing oXWllutld olnuh (kttoJls IIt(talp and() fllltil for LIbbel and IH(ltIlIlyptIJllIllIoolYlnJld-o flJllh 101 niJlsl with t(lathelr high IlPililig points 111 to n C) l]olle or in mixt tIll thllt Pll mit tlll rnphllxututioll of luhll(l OJ [middot(ill ill ~() to (l mi1lutp It r(latiwly high 1lllIllllltlltP Ill to 1~11 ) l) lllllipitntillu till luhblI OL Imiddot(ill frolll aliquot () f till oltn ion I IlIlllI-i () f Hlltabhmiddot pl(~(i]litallt (willifhmiddotd lthmwl fOl IIlhlHI Hild llitlifild lllr fOJ JP-illl t~) IIlHkillphotollllliilPIIIIiIlof PlllPlltal of liht tLaIlS mittUl(P lIftlI IlIlbll (II Il in PIlipitalioll 11 II WI( Iplllh thnt (limiJlall till PIIOl dill 10 xtralllOlh (0101 (till dptl1minntinll Iph jill 011 tIll dtwlopllIlJIl of H HIli rOI1ll tlllbidity 111 hpl than I (olot rI
jJlIlpOP-ofallnlyi-I ( p(lllil1thb IIllijOI1ll turbidity or 1llt[lIinmiddotd d(ltl of jgtIp(ii(JlI l)~ lIltlkillU tIl plllltollllmiddottri( ntdillU al tandinu tiJlH~ (dlllilll wlli(h IhlllH(lill-- IP 1llutinmiddotly tnhll) t1ll1t an hlsl~1 oil the (oJlItlIlllItion of IIlhlHI Ill I(ill (lIPIipitat((L
TIll -I(p ill till jll()(Plhul HIP 1-- follOylt (1) 1l~UIIL uJ1lplls of thwl UJfJlllHl (II tliddl(l HUt dlipd 11Illtplial an lXIllltel with11 Ill of till nlnll ill t (oU tlllltIPlll[gtPImiddotatlup oil Iath at 11 Cbull fol 11 minutl I) iIP1lIin(middot(lohd til( (XUtllhllll Jltldl lip to It middotml ynlmlll til( (nlifild by (Illlifllgiuu HlId thlPl IlI nliql1ot of tIl (IalioPlllxUlltl nll Uillltlmiddotll(t to l-llll OIlIIlIllril fiuk- (1) For a trial Ilnditlg 0111 III tlll j liJmiddot~t IllHII IIjI to Ohlllll with lilt Pll shy(ilitnnl a 1(11 it 111 (Dod fill llli lIut ( ptotoJIIltlil IPtlllillg-- of pllllntnl or liuht tlUtllIlillal(I oil n (lpel OphotnJlllllI at rase hng-tlt (If 11 llJ Ill Ol It lollllil1lPtImiddott lloyidld with tIll P10]11 I 1110110shy
Ihlolllltt hmiddot Ii1llI Olllhi lIatioll for -1IpItillg UJlproXilll1l tply Wtl P ]Plwth )0 mp are HHlltk TIll Illldillg lliJtaillld fol tIlt 4-milutl tliall(~ll-
bull
bull
bull
RAPID PHOTO~IETRIC DETERIINATIOX OF R(BBER AXD RESINS 37
ing are referred to a table of equhmiddottllut~ previously p1(pa1elt1 on the
bull basis of 4-minute reac1inJ~ for tilE nmge of lot1telltlatiol1- of rubber or resins to bE elHOlll1t(led tmd gidn thtmiddot -tnnlillfr tillIP fill rUbbEt or resins aiter prE(ipitlltiol1 lwfolE photoIllNliI j(tltlill1 un IUade The r(middotnmining dllplllatt aliquot lll then HHllil up te ol1l1Jle and lpoundadillg ale marle ut the -tandillfr tiUlE iudklltll ill rhl tall1lmiddot for the final r(adillg~ -1) 111( milli1lnm or p(tCPlltllt- of lllhbpL (II 1(-in pr(s(nt are rpadholU a prlpan(l table of lquiltlput for tlll photoshymetric readings h1~l(l ill pnell e1-E on pxpPlilmlItal lhln 1111(1 u-ing as stimtlltlds pure luhbll in 1l1bbtl milllYb aIHI guaYllh ll-ill- lxIHlatt~ in resins detNIl1111lttion I
LlTERATlRE CLTED
(1) lUnSbull 1fl36 THE mURMIXTIOS IIF IOTA RE I III OOl THER llT~II
F1 bullrol IlY U(T1l0fll UfSlfi ~rrnrl r flm lt1 KEYS TI Bill Chern 114 44J-l59 illns
t1 ~ICPHHlObullbull T 1J3bull~ lUTHOO roa THE PtRInCAnu Or a(lIUl IRrIlHU It of TIn
PLRIHEU Htllllflt [ i Bill lallllall 111 Rmiddot 711middotj iIlus
I ) RHBERG P B Ul5 A METHIlO Or ~u(ronrll-nl Hi tIII rUIl[1 f71 ii illlI
bull 14 Hoss W flbull and HARDESTY J O
llH IR1ltDII Of HfITilIZfmiddotR DllIJS ltt 1 Yl fll Off gI bern JIIIlI i ~middotmiddotlf IIl
101 SPEltCE D nnd CuoWELr ~I L 1933 DETER~n-ATIOo OF RtBBER Ii nrllllpoundRBfR Iusr 1uI II1 amI
Em~ifl cttIliIa~~ r Ell i 71middot7i l11 (HI WALTER E D
1U44 ISO~nlS OF PRTlltSrr 1trHpoundV bull l UI n W lHHt (Tnmiddot 1ETS FROM GiYI l~iIl lItr Clttrn SII J UI titJ middotn9--C1 ilIu
17 J YOEbullbullr H lO~( roLORIlETRT 771 IPmiddot nl -W Yurk f H Plrwptric hmica
naly-II rimttry lUll XphHHlnmiddot~ y 1 1
11
HI) ~ fPHELolzTRf 57 111bull Lin xw Yk t H lt PhmeHt CblUlmiddot ila AnaiY~l~-(H lithrry and XIhmiddotILpfIY Y wirh enomiddot rrJlllrjr hy H KtlJnJU11 I
t~1I --- and ~ARVER L 1f41 nlua-w ~in L liLhr IS IP ll~ XIW Yrk
bull For-sale by th~ ~a~fr1nt~nf1ent Dt~c~~ogtnts-~ s t1i rArnn~ut Pn~~~ tJffieshy
Washington 5 D C bull Pl lU ~nts
3
bull
bull
bull
RAPID PHOTOMETRIC DETERiHNArIOX OF RCBBER AND RESINS
Cox 9 proposed a turbidimetric method for rubber ana lysis AcshycordinO to this l)rocedure 5 Om of ground material is extlflcted with 100 mtof benzene for 15 mil~ltes in ri lVaring ble11(le1 or with comtant sha~ing the sltperllatant liquid is clarifieltl ~Y cent~ipoundllp-inJ~ and is maUe up to a lOU-lUI volume The rubber In i)-Ill alIquots ]s preCIpshyitated by the addition of 1 m1 of carbon tetrachloride plus ~o m1 of acetone Rubberis determined turbidimetrieaHv on aliqnots of the extract in a Fishpoundr 155-volt a c model elertlopliotomEtEL fitted with a 52) 13 reE11 filttLmiddot T011pound an(llildlllan10 pLopoeltl a 1l1OdifieLl form of the Cox method O3-gm saInpl(s of the groun(l material are extraettd oWllliht ith 11l Ill of b(I1ZellP the extrHt j (~larified bv centrifl1ing alle dEcn n tNl into a )-l1 1 youl11et ri( tlac awl tlie rEsicluE i Extractp(l thrN a1ltiitiollal time with )-1l1Ipmtions of benzene in each cas( eentriinp-inp- al1d (((calltill) of thl liquid which is added to the oriinal lxtlnet follow ftPL the lxtlnet is made up to a 15-m1 volun1e ~-Ill1 aliquot tlLl piPNtPltl into) Ill of aeetone in test-tube cuvett(s till leultillg lubhl1 ~ll-pPlbion i III ixP(l 111(1 the amount of lubbpr is (lltellllined J tll IPHIiI1 of cnttereclliht Oll n Coleman pleetronh pitotoll1orometer
The aboYpound-l1lelltioIlPd II()(Eltlllrp~ for Lubbpl nIlflly-is W(LP tet((l in the writers lahoratol hut (lid not gin prp(ip alll acculatp llsnts nppalently bp(auie of tlll natulp of tIl( rubhpl ohEllts nn(l precipshyitant used thpoundgt ClIOI cHup(lln (xtralle()lI~ eolor in tIlt Extract and the failure to contto) llflir-iClltl~middot the (hnnrl ill tlIP pilotolUCtlie 1etlllshyinS of lllbhfl in (olloi(lal solutioll Oil talHlill
ppalently 110 photomltlie IlIPth()rl fOL jeill analy-i- in plant tissue hns been reported
The presCl1t photolllPtli( lllPthod fc)J ann Iyi of rlthhlr and resins are based on the folloillf pLineiplf III (~lilH1ill tIl( properly ddecl tisslle to the rpoundgtltuile(l (1(1(( of fhHIHS to pelmit flnantitatiw extraction of rubber or 1(in f11 l1~ill o)-YlwltE(l ~()lVPllt with relatively hip-h boilinf points (115 to 230I C J al011p orin mixture that permit thr rlpld Ixtlactioll of 1llhber or [pil1 in 2fl to ~(l minutes at relatiwy hirh telHppratHlt 11j to 110 0 I (31 precipshyitating the rubbEl or [eill front ali(luot of tht olutioll- by mean of suitable rrecipitant I-ll making photOUlPtlic lpadil1gs of pershy(enta~e of light ttnnslllittarHe afteL rubhel OL resin pretipitation at 11 wave lenp-th that eliminate tht (ImI dlle to extLalJPOll (oloL (the determinatioJl relyinp- on the (lEnlopment of t uniforlll turbi(lity (1 ppl-() miller than a color for pllrpos(s of amtLY-l J I) e(uriLl this uLlifoLm tlll)idity 01 reqnill(l clerEe ()pound plp(i-lm by makin the photometric rEac1ings at stamlinf rlm( I har arl hald on the (oiweLlshytlation of rubber 01 l(in preeipiratetl ThE rrlatiou of COIwentmshytion ~)f nlecipitat~ltl rllh~pl Ot Ieins to -tnhiliry of photOlllEtrir leltclshymp-s Io dtnloped III tlptatl Oil pn14 to 11)
In rubber tlnalyis the u~e of the (lxYrfnntEll lhpnt wirh hili(L boiJing point~ eliminlltP rill II( of thr hirb1y n)latilr and toxie lWllshy
bull (ox L C A TIRBIOt(ETRfC l(~rHI)O fnR THE ~-lY5r 1F 11-1 )[ATFRULS FOR RDJIlER Rubtwr REftT( (OlTl Rpt rCnpllbllhlL 1
Jo~ES E bull T nnd YILD)L~ R G JLPID SE)([~rrlRo ~(~TlIOD FOR THE A~_Lshyysrs OFROIDER n PL-iT lUTERrU Bur Planr Inrlufbull ~oih and Agr Eogin Dibull Rubber Plant Invesr Rpt rtnpllblishErl J
4 TECHNICAL BULLETIN )20 U S DEPl Olr AGRICUlllURE
zene The solvent 11ethy1 isobutyl ketone on wl1iel~ most of the experllnental wod WJth the lubb(r ll1(tlwd Ii bas(d lH reported as nomiddotntoxic (9)
In phsiological experiments tll( alllount of nilable 1l1aietial is often vely low and lubbel ])(ll((ntats J)(low 1 PlI(Cnt- atl lIot uncomshymon Henep the 1(((1 fol Illllltl)tis lqually He(Ulntl JOt nil rnng(s of Lubber contents and rcql1iling tt 111inill1ll111 of plant lllai(lrialis emiddoti(lent It- j5 b(Iic(d that tIl( Illtmiddothods dtgt-(liiJld Oil pn(s middotl to 10 mept these specjficati(l1s In tHhlitlOll the IJl(JtClt111I(S dlS(Libcd t1wle aLC relashytively rflpid
Although these J1wthods welt ltlPlloped primneily fOI llse in rosea1eh on glHl~rule pJ~ysi()loy Ih(y hmiddot( widI ~ppli(nti()I~ riley han b(en uld til lOlltllH 1Jtul( llIlgtbpI alit l(SIIlS tlnalslgt HI an eqnal basi with the 1H0difi~lt1 SpeJlCl-Cnld(lIlllcthod in the gCIlPrul rubber labomtory Special Guayuil Rpsearclt Project since August 1043 They should alo he of ntllll in dptllIIIinin lllbbel lllldlcsins in guaYlll( bre(dillg mn(Nial aIHl iJl ollicl it ud its foJ wh iell plnnt lllatllial is lit II it((l
ROCEDUHES
PnEIAIIATION OF SAMPLES
The details of prepalation of tll( tissllc ~ulllplc are hpt (onslant tluouhollt any 1) rtiellla I I(s(allh Ploj((t Vhl11 portiolls of the same samplps are tnlwll foJ eh(mienl al1alJses h(sic1cs Il1blgtlI anc1lesins the plnnt parts alc dJi(ld ithollt PI(tlpatmlnt Yhlthpr Slpalflte mmples arc talnl1 for the otlwl analyses 01 tllP iolp pl1lpose i obtninshyi ng an estimate of the totrtllllbbel and Iesi ns tlw pIa nls Ol plnnt pnrts arp pa((d in hoiling ralpl fo f minlltps (paJJoiIN])l1 and uny lCfiyes slill adhering to tIl( SIPIlIS alc 1llTlowd hv ta pping on a table top
The plnnts 01 plant pUltS nlp sllbslqucntly coarsely ground in a Viley or otillI suitablp mill and drip to pc1(Cnt or iPssmoisture in a IllcChnnieal ltomNtion onn at (joj C l)(OIp thp final grinding A drying period of nt least 2-1 IlOu1s is IPqu iLN Ill( dried tissue is then grollnd in a ltnml11t1 mill (n llntil it pasls throllgh It 2- or 25shy111m SC]pe1 Th( mill is prodded with a ground win to Iemove stalic elpctricity fronl til slmpl BltWll1l snmplpsit is (]ennNl thoroughly by blowing with eompllsHd niL The ground samplps are tOl((l in ahtight contaimIs Viele-mouth
bottles Hh metnl 01 plastic SClPW tops are 1I0sI COlwcn ilnl for this purpose
8i11(( the J(lsnltsin mot physio]ogi(1I1 PXIlltlinPllfs nre Ixplessed 011 the basis of tllP d I wpight of hI otigi nil I Sit 1I1pJt (II)(d to (onsiant weight at 100 C it is ltifirable to (SPIPS thl finnl IlIbhCt awl 1(ins contents on tlw sn Illl basis A (OlIP( iOll fad Ol i- t h(J(fote d(I(Ishymi1Nl Oil the (inply glOlll1(l 1lotol1ghly mispel sample bY dtying snlnll rluplieate SllbSHlllphs t 1 to 2 gnl) 101 R houts at IO(Fin In ordinary
U rhp plncO( of Pl Iboiling- g-narllllt 1111111 fOI IPIJ1f1yn I of 1(1Y was dyploppd h (mplop of th IntfI(ul1titwlltai Rllhllpl ro CL r (lI(III ]Jxj1lillHntmiddot ~-24) ~PJlt 15 1928) lind nlo IlJlPlirc1 by otlWl flJIployp(s ill Intpl YlI1l~s rhis was nS(PItaiJ1(1(1 from til( fi)(~ oC Ill IntllOIltilllllal HnbbPJ (0 now fill 1110))shyclty of till U S DppuLtIncnt of Agrlcl1itULe
bull
bull
bull
bull
bull
bull
RAPID PHOlOMErRIC DETERlrINATION or RGBBER AND RESIN) 5
drying oyen hen the samples are yery snlall minimum umounts at tissue in wry small weighing bottles t35 CIll high and 22 em in diameter) are usee to (Ol1SNTe ti-ue The sumples pound01 analysis are then w(iglwd Ollt Oil tlil llalis of (onsl Ltlt dry weight at 1000 by using the factor fol 1l10isttllC COIlP(fion
lJAGE~TS FOH RtBBEH AlALYSIS
In a l111lllbpl of eases in tllis -(cti(Jll nnd the Olle on Heagents fotmiddot HesinLllltlvsi It(llllilttl-gltlde dlllllieal whielt were the best obtainshyabll during tIl Wlll])(gtlio(L fLtP indklttd These proed adequate but wllln b(itleL glatils HIe inailahle tIll) (HII he cl1(gt(ke(l to dcleLlnine lny adntntugts of lIbsl ituting p gllltlps rill nbbpl and rtsins soh-enls HIC kept ill glas--ioPPlllll bot Lt
Sollenl~-Methyljs()lJlItyl kl~t(JII(gt t(hnicalgrllll lIbOIl amp Cmbide Chemshylenls COlp is (nUlply latiII(tOIY fol 1I1ltuIHI 11IblJl1 lt is IPportell us appalshylutlr Ilontoxie UI) Although it has thp (IHIIl(fplJ it IWOIll ollor this is leSS IllOIlOUIl(ld than that of othlr IHIOIHs ((Ilsfnuls fol this lIud other rubbel -lIlrellts art given in tuble 1
lAlllE l-Propumiddotfirlr of Hfulr drubIeI olld I(~ills SOllCllts completely soIlvie in 9JpccI)Jt cUtawt
olu billt r (reshyHnilmiddot lation to weight mg ~yenI~NI~ I at (J0 C)point ~1hSolvent FOrl1uh (Ill llOlnl (IIlII(l
lUIIl ruhber 01middot Wut~r llg nlI in lusomiddot
wlter vent
Hubber sohcut c c Benzene l _ elf ~nl ILU olulole ~[NhYI iobutyl k CHltlH(JIC(J(H II 23V do
tonl LNbyllHlfllyl ketOlw (If c1I3IUIllUmiddotoCli lW r 4S U _ do 43 1 1 Diiohtllyl kNone ICH([JemiddotJjlWmiddotU(ll(I1 11 fln 010 06 45 Butyl nCltllt~ (I1roeJ(I1 12fi3 a7~ do fiS 12 ~Iethyl amyl atNnW (ljCO(j(lH1 (Jl(J1lIJ 1 IIi 3 131 lt10 13 1lS Ethylene ~IH-oI dimiddot CjlJO( HtI1O(fh _ 121 I 3J () 110 210 3
rtllyl Nlllr ~middothutyl (ther (ThO Ih 112 37 ~ tlo 03 19
Rcsins oh-cuIsACNone I _ clI C()( If I -~middotI lrNiuhll I()() 100 cetonylnclonp Cn (middoto(JJcHlt()(I WI I ~H tlu UKI llJO EthylD( glycol mollmiddot CHUCUCII0H 13[1 rl2 _10 1(10 100
oNhyl Nher (((lIoshyFohc)
Diethylene gly(ul 3u 7 1111 ~flo lOU 100 mOllohutyl Nlltr Ibmyl carbitol
I fncllulbullbull j lor rOllp3rison lnly
RIlJJIIJ1J( (illituliIlQ SOIIIUJII Oi-I)PtcPIlI n~() (c ll rellg(nt Ill Pont SP gr L~H) oluUolI ill JJ-ptrtPlI( p[buJo Ily ulullIe iR upd as a lUlJbel Illpd) tall r
lrue(it-c Colloid SrltlioJ for RIlJIII A middottipcImiddotPllt iulutillu of diglycol stellshyInte S Or glycu~ttlill a retllJld g)1I11 ur tlid)(middotul nlmt Hot llYailllbe (luring the war pellod) (bUIll tlellnj(IIImiddotIndt Ulycu Prot ItI (middotu- I i IIllHlt ill lIl0lj)homiddot lille (lecbniC(ll-glu(p EusnHllll I TIll slJ(k ur digl)( [ptrlltp ~ ued ill these expfliruellts on till bUSh of tim (htPlmiulltiom nt iJ C IYIIS illO(i 1-ereClt solub( in lll()rptvlilH) rlJe diglyt1 f(Ulute 8 i blOght U(II lllutiOIl by heating tll( oluuolt is made up 10 olmn I t a tandarll tllllf)(rtltUle (25middot
J Z30 King ltrcet Brooklyn N Y
6 TECHNICAL BULLETIN 920 r S DEP1 O~ AGIUCULTUHE
in the Writl Inborntory) al1l1 fiUerp1 A [j-I~re(gtl1t solution of this by volume is then made it thu k(tone Htptate or l(hPI or tht llIixtlll or tlH~p I~lll as tlw lullber foinnt
REAGENTS HHt RESINS ANALY3IS
Resins SUITIIN- Illixlule I)f a parIs ot lll(IJII~lIllII(JIll Hlld j pnrl~ (If fthSi IllI glnmiddoto] IlHlll1I1thII Nhpl (l(rtiIlHft(l 1CPIlPi i 0 as (middot110lt01middot1 I hr 01111111 botl t((hni(ul-glu(p CnlilOlI amp VHIhi((I h(lIli(d~ COImiddotpl is a gooe1 r(sin~ soiYPllt ~Ihis lllixtlll(I i~ 11(111( (0 ilS 1((loll~Il(ltlJlIPmiddotllll(Jllmiddotl amiddotmiddotj ill thl ((xt (011shys(allts I)f thf~( a 1111 011](1 rl~ill oYlll(s tn )inlI ill lalJl1
R(IIrmiddotpimiddot((middotJitlltill1 iWiIiOl- [i-(J(middotl((middotClImiddot 1I~O (e p (agln Oil Ponl f1 gl 114 J solul iOIl in HO by 0111111( is UStl m I Ill llills pll(ipita nt
Po(- i ( (ol()icl ~lJ11I1 iOIl Ol t(8Iyen-A O-IlPI(lnt olnl ion of (igl~((1 Rtrl ra i ( H or gly(o~t tlill I lIIath ill I (p( ollyln((1 OIl(middot(plJool( j or nlly ot Itpl rlsills solnnl 1I(tL TIJl diglYlol Hipn Ill ((i ~ is (lis~nlaquo hl 1 Itll tillg Illl lolLttioll i 11111111 liP 10 ulnnl( nla Ht1li1l1H11i tl1Il1ltIIItlllP Hilt 1IIllI((1 If thl -oll1liol1 liOllltl )(lOIllI loud) II((IIIP of II drop in ((IIII)(IH(III( 11( plPtipinll may hI hlollgltt IIHI ito ltulutioll hy It(lItill~
SIECIL EQrllIE[ Fon HlIlImn 1) HESS AALY5IS
11I0T())t1~TIG ISsTH L)IEITS
8((1111 tylllS ofi IlstllIIllllltS i Ill 1lid i Ilg tltl C01lIllflii e ] (((Ioni( plW((lJl tI OJOill(hI (oJ II1Illll dolllJltmiddot II lOll el(h1011111 t OJ SPII( IOplJOtollwtpJ Klett-Sull1llllrSOll o1olillltlI and EnIYIl pllOt(l(h-tJie cololimettt han b(PIl II~~(I TIll pilotoflttolOIlIltll apptUPlltly is llot suited for thl pUlposr iJltHlIP thl (hllJlIh~Jjstj of n( l-ollsplllliOlI IlHHStl1lll waS SLl(h that thplp WlIS velY ltLpitllhullge ill the rendingS oil standing of the liOlllt iOll a1tlI rubbl1 nnd Il-ill~ plltipital iOll fltP onitL of prefmiddot el(llce fl(lIll tilt ltalldpoillt of gllntls pllri-iol1 of llading~ is us follow
(1) CoWlIlan dOllhlt 1ll001O(ltlIII1lH I01 IWl1 Iuphllt 0111(1 PI mo(hl lOH 0 COPIlHlIl I1I1iY(lsnl SP(ctI1I11holl1nHt(1 Ilwdll 11-WaYlmiddot1I1g-1 It Rlllinl II t j() mLL is IlCIUlIllPlldl(i
(2l EnblI pholo(lptlli( (olulilll(Il1 wi It (Ining- 1II11 110(IIIUIlHl tie filt lr rOIllshyhillatioll jtl lIllL 12middot112UGc51- villstllt (ap i~ ~(t1 10 ((Jlr nl)lOIptioll IIt tllllP Wlllll 1(IIilll~ HI hlill 1lI1lt1t A nitmiddot fill holding 11 Itlllll nmgllifing IIHli til flllilitatt lIlaldll~ IIPPluxilllllll 11llIII11111letl1 I(adings tn 01 lila) hc IIJ1l1l1fll(lllld 10(lllIy
(H) KlpttmiddotHlIIllnllISOIi (OI(lIilll(tP-So ~Ililllhll Iiltpl (lInrllinnlion of IIPillllXimiddot nwlcls 50 IlIJL IIln( (Ilgth I atillhl( at 1Il(middot~(middotIlt Till ill(ItIIlWllt IWIfOIIlIS Hn tisrt((oil~ wit It th( IlIa iI II 1111 filt hpi ((11 iji 111111 njij IIIl for IlIlIlI(I II nIl1~si on 2-S(tllolll (Jl oltlll glltllh 11111 (prilll wit hlt l(lJlo((1 a 11(1 f(IJ~ currentmiddot plon ~1(jlh (101l IIII plnn[ with 111 t (1 ahlllp W(J IllJL 1l( lig Hl llIi 1illlit it USP(IlII(S$
ltOl the JlJ(~(Il( tlt( Ewlrn pllOtolIl(1 de (oIOlinwhl i 11(Olllllll1H1(d as (hI IlOt eOt1PlliPllt alld ndaptabltmiddot il1trlIl1lnt rOl rout illl lnbolttmiddot t OIY alltl ly~(-
OTIIEH I~QUIII~YI
A lhplllIoI11 i(ally (oll(lollltl tlil huth wilh a l(llIun1l1l (1(11 hllsk(t pllllimiddot liOlWl [0 hoW il)Il YOllllllPI( lIa~k~ ltig ] L llihglmiddota(]( tylil(il oil ~ K O i1((1
A tlt(IHW(1l tielHr (mil 1lIl1td 111 Ipl 1Jr t It IIIIIjdlt wir It lHolol iImiddotI(1 Illld IClllollhl ~(lllI IlIl~kl[ 1111 lt it jllll(( t h()1( i II Ill ltlOmiddotml Yonnrp[ riellllisl)I 11( in stnlltIItlllllg I Ill I lPlI (II 11 of IPII)(l1tlt Hila IIn)UIII of (xIII(Itl saJlpp~ Illkpl1 (01 Ilnlll~~i~
bull
bull
bull
7 RAPID PHOTOME1RIC DElERlHNATION OF RtBBER AND RESINS
bull
bull F1(rJm 1 ~ UIIIltan 11l~IIlInIPIII lo UIIlallt-lllllplalul( ~(II(Inl-[lllrpose hath 11fil1l liS au oil hath Xlltl ~IHinl 1(IIIOIullll win 1Jt[PI 101 holding ~[j-lJll Yo1U1l1plllt flask dUIlng- (xu iOIl ur luJhl t IHI IIill IlIi is uot stlludard ltfJuillll1ll1t nIHl 111lIt hi 1Ill((1 b1 (hI Hllal~-t
Ilm1ll E JIItnslIlPil iIIit (111([ (Iltaslll(11 [1111 In(J nlHI K()(lak electric tinwl Ilw Hutpl H~ 1l~Id ill I1PIIIllIillillg )1IIIdillg (illll n((uInl(l~ 111 111lt minute unll luhllpl HIII1 Isllll al( l11(ipIIIIlP(] 111111 till tOIlIlPI 101 tinling hlHtillg nml (11 tli fUli Ilg 11l1iulls
AWill~ 01 It Ball amp I(wpllluill fol Ull initial lWUSI glinllillg of gtllyul(l UsU( Hoss-llal(]pslr IIWllifillIlioll of Ihl lInlllllHI 11Iil I I plIlIilll] with Xo 1
(~middot1Il11l) nl1d XII (iIIlIII1 (lPIItS LYIPX i lUl(l lOOmiddotml oInllHUilt 1IlI~ llloidltl witlt grolllHlmiddotglns RlOPflllS spr-ial mIIIi 11lx ItitUllIti IIllIkll wllh UIlI illlIlp 1111111 1111(1 gillS
10(1 12 CIIl iclllg h~ 1Ii jlll ill Ilillllllitl wHit gtOllIHI UnllIIPti IlId 1 em In dillllllll fOll1~p illlllllldllg lIbhll slutlon [fig A IUHllJ) 11)( jllpiul heakcr I lIJIIlI1fIIIIIlII11 t101Il Ihl W-1l1I lldUiIl low-fllllli 1IllkI wilh s[lout laquo(olning (llas WIllk Xo 11111(1) Till ll (toul I flatlll1lt1 hr (Ill lgl1lu glllliliIIOl[ing Plo(Il1m Ill IillltllIllI 11111 of Ihl gIllgt ruti aIHI IIIP sUIfa(( lit til( lIat insitle hottnlll of IIII )11111 nl( gIlltlIHI toglll)I wilh Itll(I~ ill 01((1 II) s((Ule the most II tisflnlory SulfH1 rill lil Illl I iOll
P~I(X WIIlIIt glI III 111( ll111L ill thilkms 10 II~( a It tIHS(~ III ([hiding luhl)(I Sfllll[llp
A Iolk Imil fill lISI ill diiltlill~ luhI 1111[111 H(Hy(Inl~ 1~T(lX 10middot1111 gllhmlllI (Pili Iifugp t 111H Ill]lillld wll It (011(1 1101111
lind (ork tupp (0 tit I Ill 2 ()
bull Filt1 tilk (fig 2 IJI 101 1)( with Ihl glltllunlld tublS ill thi o[WIati()n of
llOUling lIIIlillpli lx(nll illf jIIlI )lhIIIl1IY(I lIask IYIIHIlt ([illlluin l(slmiddot Ill At hp II11IPI a )Iuss lOI wit h I tIaltllll(l (lIll lIlS lI1ullIfnlul((l ill the Illhllln(()I~- fol this l1SI bill ii In (lilli(ll1t 10 -1(111( II PIIpound((( tit Howlwei tlte anilnblp filtpl ti(klIt1 tlll 1)111)111-1 lind was Intll lIhs(i~llll(l The fritte(l glass disk SII(S 110 rUlli1 lUll Ill llIlI in tliH O)IlIUlhJll hut hollis hlllk the liqllid II nil lPidlH in till ((111( PHill
Cuullipl(1))ipp(ll for tlllII~flJItng klotlls nnd uthI IlIgnnk Illnnis SlIInl pighin) III I (h li (Ill high alHI (III ill ([111111(1
8 TECHNICAL BULLErIN 020 e S DEPT OF AGIUCUUlUlUJ
bull
IHHH middotmiddotmiddot~Ollll of the ~Jl((iHI ~lnsswlI( reshyquilpd 101 [lh)lI and I(sills tllal~sis (lllss rod wilh lInttPIH(] (ml Loll alld tlitulatioll lJlll((I II]) 101 liSP ill bull IIlnlln~ sto1 solutions of IlliJlPI (olII1i lwanshydlltr -AIIlI lYIX ((1I11ishyrllg tulJl wit Ii 011( poillt (0) nIHI flIIpI stie ( J) I fOlllSP ill P[)lIill~ utl (llIdiIli (X( lels witlt shyout di~tlllhill~ the inshysulilhll Ipsidlp
bull
Glns pound1111])(1 ) jlllll in ((iamptl for 1( ill tltlm~rprljlJg- pighpll fllJlplpS HIIl1
bull (lnrin(d IXIIat to -llil ohllnlllI f1aI~
i(p-mollllt gingt hntl will llntit OJ 11I(lal J(IP (n] fOI toling- gIollIH plallt samp(
Halmiddotk for hllldhlg ill-llll middotPIlIlilnp nlHs IIIH ~i-1I11 YOlIll1pllit flll (Jig- 31 Alltolllnti 10(1-1111 ~middotI(lX IlIllPUp of IhI fq)p llsltd fOl Iitis with intpl(middothallg(middot
nh1t H(JlIlHI joint 101 rl1phl lPfIPIIIlg (lj 1lIhhpl fllld 1(ill lll((jpiltlllls
bull
FllilHE Had Iqllind fool IIJI(lill I 11 (111111111laquo llllmiddot alHl (I) limJ VfIlIlllllJi( tlak~
bull TIll itl1jHlIlWI of n Illb tlpl of d(Hdill(~~ III [gtJ(Jtnllllllil lllll~
i dblmiddotwmiddotpt hy Y (J( I _ j J i) t Illt riflllmiddot t tth~ n n Ii 11 111 h111 I t1loOIlldy witl nap lllltlIHI 1111 1l1id bpll tlll- HII lill(ll with (jtt11lill olutioll Hlld ltll If fla k It It [lllijljtnlld 111bhll nl
11ill lIll til ~tlllld all 111th Ill lillI Illmiddotforl 111l In 1(11 it j~ luhmiddotjlIll] 10 1111 0111 ilH (111(11 11[ Jpli~ Ii tllp wall TIll
10 TECHNICAL BULLETIN 920 U S DEPT OF AGRICULlURE
25- and 100-m1 volumetric flasks arc rinsed two or thrce times with tap water and then with cleaning solution al1tl watel as is customtny In all cases the rinsed glassware is dried in an inv(ltell position at 100111 temperattlre 01 upright in a drying oven The flasks used IoJ extracshytion of rubber Iron1 kok-sagh)z (Talllrl(((IM1 kO-8aghyz Rodin) are finally rinsed wHh the solvent to be used and are nllmnd to lt1Inin and dry under a ventilated hood Cuwttes 01 absOlption test tubes nre handled and cleaned aH directed by the manufacturC)s of the llhotoshymetric instruments used
RUBBER (CAOUTCHOUC) CALIBRATION CURVES
GENERAL CONSIDEHATIONS
The lubbeL hyclroc~rbon stau(ild is pllpa 1((1 by extracting the rubber from guayule bssue ac(ordll1g to tilt SPCI1((-Caldw(llmethocl (5) 01 by the Holll1lH-HaasiH modification of this method (p 2) The air-dry extraeted ltlbber is dried furtlllr in It vacuum OYCl1 with 30 inches of yaCH1Il11 at 63 0 C for 4 hOlIlH Till rubhlI sbindanl is preshyserved h1 It clos(cl contaim1 sto1(d in It r(fligellltol BCfole th( samples nrc weighe(l out the unopened cOIlbdn(l with the rubber i~ brought again to room tllllpelutnre
Two stock solutions each in triplicate from separately extractml standard rubber satnples nre prepared-the first sct of (-111(( containshying 01 percent 01 1 mg of luhbC1 ])(1 lniHilit(l and the other 02 pershycent 012 mg of rubber pel miJlilit(l TIl( (I(~il(d w(ight of rubb(L contiiinec1 in It known VOlIl11e of th(~ solycntis withdrawn Irom Il
burette or pipetted and made up to 25 m1 the standard volume used throughout the procedu]e
The rubbcr samples (01 and 02 gn1) for the stock solutions are weiOhecl out to an aCClllal) of o~ mg on nn analyti(~al balance The rubber is best mnnipulated by mNlI1S of t1l( stJai~ht hlunt-edged top of It cork knife With a little prnctie( OIl( (an leltlily sepnrate t)w desired portions by pLeSSIl1C from aboye Further subdivision Is mndt on a stout PVllX at(h glnssnt lla~t 2 mill in thlkne~s By pressun f10111 above and sheuling aetlOl1 Ye1~ small pnrbcllH can be separntetl so that the requit((1 11l110unts (un 1)( w(igh((l Ollt accurately The rubber sample is then divided into sl11a11 piC(es on the special watch glass by meanH 01 II coll Imife
One mil1ilit(gtl of lt1i isobutyl ketone 13 js placed in It special 30-m1 trituration beaker (fig ~B) and the fine1y diyilt1ec1lubber sample (01 or 02 gll1) is udd(d and heated on a hot plate under n ventilated hood to Il tempelature jllst under th( boilin~ point of the olvent A special glass rod il used t () t rit II ate the sumple (fig 2 11)
When the rubl)(r hll d issohed so as to makl a hOll1og(J1lOUS geUike 111I1SS hot methyl isohutyl ketone or an oI the other luhb(L solvents recommended (t aIJI( 1) is add(d and niicd with the rubber soltItion
31 Diisoblltyl ketoul WIlS not aailab1p (Juring ValtimC l1Cthyl isolJutylletonC 1II1ly be substitnClt1 11111 it is not a~ Cf1kiCni In Illis olllntion If the IllttC1 is used It is b(SI to pl Ilw fimlr diillPll Iubhpl palll(s slan( oPIuight in Ih( solvCnt lind 10 (OPl til (onlalll1 to IllinilllizC elIpornt(111 of sohPIII bpfolp wa( Is nppliecl to completp nlutioll
bull
bull
bull
bull
bull
bull
RAPID PHOTOMElRIC DElERMINAlIOX OF RUBBER AND RESINS 11
The mixture is tllll1sterled to It 100-ml yolumetlic flask with sevtlul washings of hot solvent cooled to n s(uHluld telllpelatUle and madtmiddot up to volume with the saIne solwlli SlwtiaJ IHl(uutioll mllst be takell in transferring t)( lubbCl solutioll to till YolulIHtrie flask so thnt llO rubber is lost It is cOllytllielit to illSllt It j-ill(h funnel in the ne(k of th(~ voiumptic flask to pOll tll( lubb(ll solut ion ill OIl( OLWlHtion into the tube of tht IUlll1ll with Ihl aid of tIl( glllss Iod nlld 10 follow illlshyl1eilintely with S(gtllnl ~Ynshings of hot S() I(111 whkh lIl lilst pouled 1nto tIll btll PI 1I(ld dIIleUy OW) till 1unn1 aId IhpII t1I1uugh Ill( funnel
H time hi not all objllt it is uls() flasible 10 p1alt Ihp linely diided particles of Iubblt ill tl( flask toJ1tuining Ihl sohPIlI 11(1 allo it 10 stand until til( 1lIbbpI is dissolYld TIl( llIblJll ioluliol)s alp slolpd in Ihe tightly s(ojlP(1(d OIUllwt lit f1nks in a ((lol dark placl Thel they willltIIlUlIl (OlUilallt ill Idut 101 an indlfinit( JlPIiod
Two ellliblHliol1 (IlP~ flIP IIltl(l(-OIl( 101 o~ gill of tisHlIP (ollin illshyhw 0] to 10 PII((Il of rubb(I ((1lt)middot1 to U mg of IlIbb(Iill tt ~)-1Il1 yo1ullll) and th(middot otlHl for ()~ gil) of tisslIp (ollaining 10 10 ~l() peLshycent of lublJPl (O to 10 Illg of lulllJpI ill a ~)-))Jl YOIlII1IP)
(Hns HlJ 111 TO 1 II~IWEX( (II BIIII1EH
III oldl) to ll(llllP (ITOI (0 II Iltinil1lIl1l a lIitahl( lllillobllllltp is lIs((lo Jl((lpn (P IhI ~lt of stal1da Id solut iOlls 0 f a Ii ng (OJllllllllll ious ill til(gt (III)(r( Ol 10 1 gt(I((lIt of LubbI In (11( PI(sPIII WOlk th( 1111shypIoypd HlhlHIg mic)obm(ltp Il bullJ) whkh lIi(IlJalpl dlli(I~ 10 0001 1111 was Toulld sntisiadOlY F(OIll n lll-pltIllllt -talHlulIlllbwl solushytion in HSlIitnbh solnnl lt[lIiIlIUJl1iiat( aliqll()l~or n) Ol o~ n and ()t 1111 al(lllla~UIpd (Jilt ut n stalldUld ~Olllli(lll tlIlIJl(1atulp (~) C ill wlitllmiddots labolulol) I IlIIHIl-of II lllillOillIl(tlt illio ~l-lld yohulI(lie f1nks ploid(d it h gla -(OPIllIS gllollgh of 11ll lubhpl sol Pili i~ thllI addltl to (tl(lt flask to IlIak(1 l 1111 Ill1I IUI(middotc (0 t hl all)ollllt of lllbOPI solutioll ]ll(yiously nd(lpdbullflll DI ntl 01 JlImiddototlmiddottli lolloid solu tillil Iras h(PIl Hddld lIP (bhpl is JlI((i pi III tpd IIlld SP(middot(t )opl)()tolllshyd(gt( 01 (jIOlilllltp) IPallil) an IllHdp 1I((OIdillg to 11ll JlI()(pduJ( Oil shylitwd Oil pagp 1middot1 Th( 1(ldillg~ 101 palmiddotll (OI1((III)Hlioll alp 1I(Iaglt1 anel plotttd Hgaillsl t( ntilligllIlll of 11))1 hI n ~)-1ll1 (jIIlIlH 0) [gt(lClntagl of nlbblI (nltuln(pt 011 tw bnis of tl2-glll lilsul Slllllp1(gts and aliqilOt olulllt IH(IOI 101 (itl ]1I(J((dlll( out lilll(1 Oil pagl 1middot1 This PI()((lhll( i ((l(alld t win ill (a(1 (11( II slandald llIbbllsolushytion was PI(gtllllpd IIOIlI slpa latll XllH(1 ld 1 a utln)(l lllbblI 1 III pips TlwcOlllpl(tpdtlla alp pol(l (1) (loldilla pap(laslrowl1 ill figulp I
Tbl )llO(p(II I ill lllilking a (Uln rOl I to ~ jiI((lIt of JlIlJh(1 i~ simi1t1I to (hat rOl 1Ill l1IlP ImI1 to 1 JllI(PIII (x((pl ill a f(middot dptnils The quinlu]lli(Htl aliqllols a 1( sput(d Ht (lI 12 a j 0 (78 n alld 10 mg ])(gt1 ~i-1Il1 Yolunl III sNuIing thp 01 Illg pll 2)-Jll1 YUlll))lt til( (gtIO(ltlIII( outlillPcl ill IIIl PIp(tding pnltlgllIph is followpd In the rllngl 1 toj Illg )IN ~)-1I11 OtIIl1I Ilw (lsi 1(lt1 (oJ)(tlllltlliollS of lubbpI alP s(gt(ul(gt(l h IlIPHsuljng alhplOi- with Xnlional BIII(atl of Stnndlld~ tltllsf(I pip(Ws flOIl) tltl OI-PlIl(1l1 lII))ll sol III ion
12 TECHNICAL BULLETIN 920 U S DEP1 OIr AGRICULTUHE
RUBBER IN 25-ML VOLUME(MGl
100 1~__middotOT5___ITO___15__2~O=--_bull 2r5_---= bull 3rO__~-_40 bull99
98 shy(I) CI Z
~ 97 ItJ II
~ 96a f-IIJ
e95 o l
94
93
92 ~__~__~__~____L-__~__-L__~L-__~__-L__~
o 1 2 3 4 5 6 7 8 9 10 RUBBER (PERCENT) bull
FIGURE 4-Cnllbrntioll curve for rubber in 02 gill of gt1n~ule tissue containing 01 to 10 p(rcpnt 0 lllbhlI (nlnllillg~ (Ill 1111 J~pl~ll llhooplf(middotttmiddotlc colorimeter with 720middotmu filter und amiddotml uperture the 01 divisions required in actual pracmiddot tice for photometric IclHlings arc olllittltd)
Similarly hl the range 5 to JO mg pel 25-ml Yolume the desired conshycentrations of rnbber urc measured from the O2-pllmiddotcellt solution The complete data lire plotted on semilogtllmiddotithmic pttpel as shown in figure 5 A
STANDARDlZATJON AGAINSL G1IA111 ETlIIU 11 ETHO()
1he alternate ploee(lule of stt121l1ald izing th~ IneHell~ method ngninst the Spellcc-Cald well method (II) altholl~h flaSI hIe 18 not adVIsable because of the extra work J(quiled ancl the introduction of the expershyimental error of the benzene extraction method
HESINS CALlBllATION CUIlVES
The procedure for constructing cal])lation eUlves for resins ttIlulysis is similar to thtni outlinlltl for lubb(l lxcept that resins exndate of gunyule is lIsed as the resins stundard The resinolls exudate disshysolves very readily in the resins solvents listed in table 1 It may be prepared in two ways for use as a stnndard-the clean exudate as bull gathcrcd from the plants is dried for 6110mB nt 65deg C nt a 30-inch ltcuum or the oXllllate is dissolved ill acetone and filtered In drying
bull
bull
bull
RAPID PHOfOMElRIC DJllImlMINAlION OF RUB BEn AND HESINS 13
RUBBER IN 25-MLVOLUME(MG) 2 3 4 5 6 7 8 9 10
r~
eo en ()
90
f--70z Q ~ 60ltl LIJ a ~ a LIJ 40 E 0
0 50
~ 0 ~ I 30 0 ~
A 20 I I
o 25 50 75 100 125 150 175 200 225 250 RU88ER(PERCENT)
RESINS IN 25-MLVOLLIME (MG) 2 3 4 5 6 7 8 9 10
1--90
80
en () 70
I z Q 60ltl LIJ a
50 0
a ~ LIJ 40 E 0 0 ~ I 30 0
B ~I20 o 25 50 75 100 125 150 175 200 225 250
RESINS (PERCENT)
lJIGunE u-Cnlibrutioll cUve for (il) rubhcr in 02 gill of gllnn11c tisme conshytainingl to 2G perc(lt of 11IUU(Il I1na (1]) rpSillS in 02 gill of glI1~l1ll~ tissue (ontnining l to 20 nelecnt oC l(sin8 (U(ndings Oil 1111 E(lI~1I llhotollectlit colorlmeter with 720-mtL filtcr and O-ntJ aperture the lO divisions llquired In uctnul prllctlce for pitotoulPtlie PllllillgS tlre omitted)
in vncuo arelntivply HllHlll qUllntity of (xutlnte is plllcel] in a lalge dish since the mass rOHmS nt the beginning of the drying process Pracshytically ull of the ne(tone is evnpollltpd olf oyer a steam Ol WItter bath and the residue is dli((l pnlYllized in It mortnr and preserved by
14 lECHNLCAL BULLErrN H20 U S DEPl OF AGRICULTURE
drying as indicated for fresh exudate In all ClSeS the products are stored in airtight containers in a dark coul place
The usualllnge of resins from gunyule tissue is about 2 to S percent on a dry-weight basis For work with this plaut therefore on1~ one curve is needed A typiCallesins ealibrntion CUlTe is shown in figure 5B
PnocEDuuE J~OH RUBBER ANALYSIS
Duplicate lXiLllCtiOllS arc made for each tissue analyzed and duplishycate photometric readings are made for each cxtmctioll the final value therefore reportcdreprescnt- nn avcragc based on the four phoshytometric readings
Thoroughly mixed O2-gm samples of the finely ground tissue are weighcd for analysis on the basis of l11oistUlc-frec tissllc The samples arc weighed to an accuracy of 02 mg Oil an analytical balance The method of deriying factors for making eOllections for moisture in samples has been thtailed on page
The weighed samples arc trallsien(c1 to the 2-m1 volumetlic flasks with the aid of l-inch glass funnels and 20 m1 of methyl isobutyl ketone is added to each flask The contents in the Hasks are heated m a constant-temperature oil bath at 115 0 C for 30 minutes uncleI a yentilated hood rhe flasks are removed and any adhering oil on the outside is wiped off with Kleenex 01 H similal cellulose tissue the C011shytents of the flasks am cooled to a standard tempellltule (25 0 in the writers laboratory) in a constant-tempelutllre ater bath provided with a motor stirrer if available and made up to volume with the solvent After the contents are mixed the flasks are allowed to stand for a few minutes until most of the insoluble residue settlcs to the botshytom The extracts are then carefully poured into JO-m1 heavy-duty centrifuge ulJls so as to include as little as possible of the settled insolushyble residue The centrifuge tubes are stoppered with cork stoppers and the liquid is clalifiecl by centrifuging for 10 minutes at 2000 revoshylutions pCI minute The clarified lIquid is poured into 25-m1 volushyl1Ietric flasks plOicled with ground stoppers It i impoJtant to pour off the clalificd (dlart in lWIt a lUlllie that the ill8ol11ble cNi(hwis not Sti1((Z1tp A 1-in(h funllel is plncCd in the neck of the volumetric flask A filter stick (fig 2 D) is inserted in the centrifuge tube through he liquid so that tlH enlnlged palt of the gtiek seals off the insoluble residue and a small portion of the exmet in the cone point 1Vith the index finger the stem of the filtel stick is thell held against the side of the tube towllnl the analyst who holds the tube with the thulllb rmtl t11illt1 fingCl The txtlHct is thell poured off easily into the yohunetlic flask without distnrbing the insoluble residne The COllshytents of the Hasks are then ))ollght to the standard tel11pelatme in the constant-tempentl111e wnter hath
The reagent blank us(d wit h the spectropllOtoll1lter 01 (olorimeter ig prepared as follogtvs ) 1111 of methyl isobutyl ketone 01 other solvent used is pipetted into It 25-m1 yolumetric fiask and 01 ml of protective colloid solution for rubber is added the mixtule is made IIp to olume with acidified Oil-pelcent ethnnol and mixed again the rcquired vo]shylime of the mixture is poured into a cuy(tte or an absorption test tube
From each plir of tissue extractions to 5-1lll aliquots 01 the clarishyfied extlact at the stnndanl tempCraLule ale pipcUed into 2ii-m1 volushy
bull
bull
bull
bull
bull
bull
RAPID P1IOTOMElRIC DETERMINATION Ol~ RUBBEH AND RESINS 15
metric flasks and 01 m1 of protective colloid solution for rubber is added to each One additional5-mL aliquot from each pair of extracshytions is similarly prepared to serve as a key to the standing times for the final readings as indicated in table 2 These additional aliquots are first made up to volume with the precipitant acidified Do-percent ethanol mixed by carefully inverting the flask three or four times] and allowed to stand for 4-minute periods before the reading is made on the colorimeter Vith these preliminary rendings a~ a basis the standing times for final readings are taken from table 2 For example if the colorimeter reading in rubber analysis at 4 minutes is 655 then the standing time is 15 minutes
The two rell1Lining duplicate aliquots for eath extraction are then made up to volume with acidified D5-percent ethanol mixed by careshyfuIly inverting the flask three or four times nnd allowed to stand for the required number of minutes as established by the preliminary 4-minute trial readings (table 2) before the final colorimeter readings are made on the contents of the flasks
TADLE 2-St(llllliIlU time for variolls (OllccntratioIlS Of rubbcr or rcsins aftcl iJleaipitation bcforc colorimetric readings mc macle
[5middotml aliquots of rubber in methyl isobutyl ketone or of rcsill~ in ncetonylncetonemiddotcellosol e 3middoti both made up to a 25middotml volume with pr~cipitantj readings on lvolyn photoGlectric colorimeter with i20middotml (690to iiOmiddotD11) filter and Umiddotml aperture]
RUDDER I
Range of colorimeter Approxima(e S~nuling i Rnnge of colorimeter Approximn(e Standingtrial readings after 4middot range in conmiddot tJIIIG for trini r(adings nfter 4 range in con tifillnlOalcor minute stunding time tcnt In tiSSU(l Unnl I t I t (rending IIlIDU C stum Illg lOW _ tent III Issue reading
Percent Villlits II Perfe~lt Jfinul 955-999 bullbullbull bullbullbullbull 09-01 00 01-03S bullbull ~ _bullbullbullbull_ Jl-O9 10 743-954 bullbullbull ~ bullbullbullbull __ _ 43-10 30 1420-550 bull ~ ~ 137-94 5 6_3_9-_74_2__bullbull_ bullbull bullbullbullbullbullbullbull_-_---- 6__8-_4_4---___ bull ~ ~ bullbull ____ MQrcthan 13ibullbull_-~_ _ ____ 15_~elow t~ 2
RESINS -----------------------------~--------
957-999bullbullbullbull ~ 139-01 60 11419-amp11bullbullbull _bullbullbullbullbull ~~ 13~5-939 10729-956bullbullbullbullbull_ Ii 25-1 middotJO 30 ~gtl2-40(L bullbullbullbullbullbullbullbullbullbullbullbullbull _ 2025-1320 5 595-728~~~ bullbullbullbull 8 as-G 20 20 IBelow 292 bullbullbullbullbullbullbullbull- More thun542-591 _bull ~ bullbullbull_bullbull_bullbullbull 038-039 15 2025 3
I Precipitated with O5middotplrccnt HSO in 05middotpercent ethanol When the npproxilllull concentrntion of rubber or rcsins in solution is not known trinl colorimeter rend
ings atmiddotJ minutes s(nnding till nrc mndelS n guide to the required finnl standing time indicated in the last column III prncticc UII cxtrn nliquot is prcpnred for precipitation and thIs is discarded after the trial reading is mnde
3 lrccipitnicd with OmiddotpcrccntlhSO ill HO
PnOCEDunE I-On UESIliS ANALYSIS
The procedure fol resins unulysis is the same as that indicitted for lubber analysis eomiddot(I]lt that f he -olyent js acetonylacetone-cellosolve ~)-7 tht precipitant js O5-perctnt H~SOI in H 2 0 and 01 1111 of the protective colloid solution for nsins is added to each 25-m1 flask conshytaining the aljquot of the extract before the precipitant is added
PnOlmmlHlC INSlHu~mNTs UECoIUlENDED AND CALCl]IAlION
OF UESurlS
Photometric readings of percentage of light transmittance (T) ale made on the Coltnum double monochromator spectrophotometer at
16 lECHNICAL BULLElIN 920) U S DEPT OF AGHICULlUHE
750-111 wave length or renclings n1( mnde on a colorimeter pLoic1eri with the monochromatic filter eOIl)Il1l1tioJl for sllecting the npploxishymate wfLYe ]cngth at 750 1Il~ For routine deterlllinations the Evelyn photoelectric colorinwt(r ployided with aTW-lllJ filteL is IC(0l1111HIHtll
The liquid in hich the preeipitnted lubber uld rcins are susshypended is pOll(d very cHrdully down the ill~idl of th( clette o absorption tube to lLYoilllllC fOLll1ntioll of ail bllbblls Aft( LUbbet find resins preeipitation wlwn the EnLynpho(otkcllie (olo1imetll is used the readings are nmde nft(L thl standing tillll- hOWll in table~ It has been foulld (OIlllliellt to 11lPtipilatl tublwr 01 llsiIlS from the aliquo(s at ~-millute illtlLvals This allows stlilieipnt tillle to check the eOlolimet(r and to makc 111( lNHlings Vlwll a ehangp is IlltHk fLom onc rending 10 the l1lxt it is advisablp 10 llle the clIvctte 01 absorption tube nt lpast twkp with slllall p(Iltion- of the llllltiol to be leitd
After the colorimd(L lluding lta e becll Iltndp till IlIl II igllIlllS of lubbel or resins or thc lpL(el1hlges pnslnt in Ihe aliqllot are r(u1 from cal ibmti(Hl (urVlS (fig~ 4 and raquo or from plepn Led tables of eqllivallBts baecl ill each (liSP on (x[lerimPlltnl data The results are expressed as percentages of dry weight (S hours drying nt 100deg 0) of the original tissue The errol lltle to lCflyjng the insoluble residtH in tbe voltlllletLie pxtLHclioll flflsk wlwn the pxtrnetis being mnde up to YOlllmC is V(ly slight sinlte only (U gm of tissue is used FOLroutine allalyscs lhis ery slight eLlor mny be dislpgnltec1
EXPERIMENTAL RESULTS
The experilllCnlal reslllts Oil hi(lthp method- of tU)lPI and l(sins analysis a le based ttl( d icussld blicfly hlrehl
PHEPMINrlON OF SAlULES
No difliclllty was expPtitI1(ed in pltparing slmplls of llllrscly-glOrt guayule plants 1pss thnn ~ YPH1S old 101 rllbbpl alld IPSills analysis In the cnl of Odll filld-gl()n gllayull plants PIIOtS hopel mtty be introdmp(l by the custOlllalY Jlwrhod 01 pICpalillg Ihp sampl(s 101
HlutlYHis as is lwipfly i n( ita ttd ill th is s((tion Smh enOlS do llot nffCct the ])lCcisioll O[ t1H llwt hotls for LllbbtL n nd Il~in~ nnn I sis i nee till) are due solely to tIl( tbsup--ampling (llo(pdule in thi (a~e of oldeL field-grown plall TIll 1lllt1lOcl of salllplill7 fipld-gl()l1 plants JllOLC than ~ Y(HrS old thenfort Ieqlliles iurtlHl jnttigntioll
lgtAHnOILr~G FOR HEllOVAL OF UUVLgtS
Parboiling which (onisls in boiling gllltyule plants in water [OJ
8 to 1~ ~ninll(s ~s col1llllonl) uSNl a~ n llHans of Itlli rCnl()y~l prior to drymg nnd gllnllng It I~ tHI([())P ll(e~Sllr to ltItLeLnunc all possiblt~ eflct oi tlti PLOtPlllll( )ll (Il( final results Exp(liments have sh(nm that (helt i- fl Flight loss ill til tmiddotjght of lOO(S and 4(ll1S In I typi(ul lXpelillltll hlu1llHs of ~- ii) -1-ytII-old gllllll( pllllb were Italnd at randolll Olll ( of talns wa- paLllOil((1 and the le~es (1( haIHI-pi(kpd [lom till o( hpJ Ht Both pis (1( dlipd for 48 hOttlS at (i) C in a llI((lwlli(al (011((( ion Oyell Th( lpsult are SUI11111I11izNI itS follows
bull
bull
bull
bull
bull
bull
RAPID PHOTOMETRIC DETERMI~ATIO~ OF IfCBBER A~D HESI~S 17
Dry ucilht lust ill lariOilillf
Plaut (pcrcrllO 1 1 -I2 ___________________ _
213 _____bull _____ bull __ _______ ___ ____________ 12 2(
pound(111_ ______________ 1 R
4_______________ _______________ __ _____
A __ bull __ -_
The efred of parboiling on till final lllalp i SUllllllatmiddoti7(middotd ill figmc G Rubb(1 lecoYelY w(t about 1 percent higher for parigtoillltl plants and lEsills re(ovelY somewhat o-er 1 i)(lr(lllt 10Wlr The (Ii tference in lublH-l r((o-elY cannot be ae(01111tltlt1 fot by loss in dry weight _ due is to be found in a study of thE grinding lwhadol of a parboiled and an unpnrboilEcl shrub The grinding of the patboiled shlub in the hnml111 mill is much fadlitated and ns a rule for tissue with a rubber contCnt below 10 peteent llO aggregates of rubber deelop in the 1Il11ehinr during the (Jpelatioll Yitll the unpnrboilNl shrub some dillictdty may 1)( (lxppliellrl(l Sill(( sOllle of till sti(ky ltxlldutl Oil the plant may scI( u nlldei for the fmllHltioll of lublH1 ngglPgates Til is apparently explnins the npparlllt los in ruhbpl frol1l the llnpariJoiled hrllb as eompnlelt1 with thl palboilld (fig (i) TI1(loss in r(sins
II
RUBBER
10 f-
Ishyz LIJ 0 0 LIJ 0
9 --RUBBER -shy-------shy
-- RES INS -shy---shy-----_
IJ) 8 I--Z IJ)
LIJ 0
0 7 f- RES I NS -0 -shy0 LIJ III III J 6 f shy0
LEAVES REMOVED BY PAFltBOILING
5 f shy -shy - BY HAND PICKING
4 I I I 35 30 25 20
SCREENS (SIZE OF OPENINGS IN MM)
FIGlRE Ii EtIe(t IIf pnlticlp sizE Oil lEcorPQ- of rubber lind (iiil1s when lEgttiye wEre remond hr Pl1liloiling lind h~ hand pi(king ((Dlltrol) plllllt1lt groUlld in t hammer mill
6114038-46-3
18 TECHNICAL BULLETIN 920 U S DEPT OF AGRICULTURE
recowry from pUboil(d shrub may be due to the loss of the resinous exnc1ate during parboiling This exudate forms ns It SClim on top of tlw )iquol in the tank
On the basis of t1wse results the recommendation is made not to yaly the nwthoC of leaf lemoYal in any 011( lNi(lu(h project Then fltirly compalabh IcmLts should he obUiined
70 ~------------------------------------------~ LEAVES REMOVED
BY PAR80lLING ____ BY HAND PICKING
60
-I-Z 1amp1 0 50 a 1amp1 a
en 1amp1 gt1amp1
40en gt-CD Q 1amp1 Z
I shy 1amp1 30 a l shyx C)
1amp1 ~ J 20 I shy 0 I shy
10
O+--L__L-~__L-~~--~~~~~ o 10 20 40 60 80 100
NATIONAL BUREAU OF STANDARDS SIEVES (MESH)
FlGntE T-lJiMlil)utiun of l1Ultkh si~(s of gnll~II( tiSSU( JrIOllll(l in a Ball amp 1ew(1 mill to pass six dllIerNlt S(I(euroII 1(IlYes Iemoved from plants by palmiddot boiling 11(1 hand picking ((olltloll dpfo1iatld plants dried to 1I lUoistufl l0I1t~nt (If 01 to o) 1)(ICl1It ground tiSSlli IbalH1 1() minutes ill II ~i$hel
bull
bull
bull Kahn shuk(f
RAPID PROTOMETRIC DETER~UXATIOX OF RrBBER AXD RESIX-i 19
GHl~DIgtiG
bull Th~ entire pant 01 plant l)iHt a~(gt fl r(ll it pllllIIirU1ry lSillg fur J hours ntGi~ C prIOr tD t 1( plChmll1atmiddot rLlmhll III a II lItmiddot or n Ball amp Jewell mill ~n llltllysis of paldch lzP- nftl~l (oar-( IIindill shows that tlwy ar( about tIlt llllH fOl parbojlP(t awl IJllllluhoileu hrubs I fir 7)
The coalilly gloUllll ample i-- thPll Ildlll forI toUtmiddot at ni C afnr which it ha lllilobtllL(gt output of ~ llllut lII hmiddot- dptPlIIlilwltl by drying submlllpil- at 1110 fot hOtll- TIll 1 IIIIll i lltllt lmiddot0l111d hi a IluninHl mill TIll mo(lel uP(t in thi IIIk i 1I Hu IIIOilll mill as IllUllifill bv Hoss nnt Hartlet ( 1 -[1lt111- with n1ll1l1 pldushyrations ittI lilnbhell b rill HanlIolll V0ll11nHiol1 ElIillllmiddotrill (0 The size lutllihl11 iUlJnole So I ( 111m t ~ II t HUIII Xl) ~ I L~ 111m nnd So 4 lillllU1 11 ttllilhmiddotj 0 r tllP Imiddotlult~ p(lln-It willI t11(e Sll((IIiZtS with )arl)Oiltll awl uil)Jtllboiltd hrlll b lOwl1 in fif1l1fmiddot-- This hows t tnt 1middottttIl ~(I 1 llllll (Up jlllilnl IHlt that
r------~-------r--- ~ --r IHAMMER-MILL SCREEN
O~ NO1
NO2 ---shy U NO 3 ---II
I
bull lL
z
r ------ l 30 ~ gt III
i I Imiddot
i ~ I
I 1 I I
~ 20 I - 1 iii 1[ r 10 ~ ~ ~ I _ ~ I r A bullbull
o bull L-~__~__~~__- ~~ 20 40 60 80 100 40 60 80 100 200
NATIONAL BUREAU OF STANDARDS SIEVES (MESH 1
Yutln I i-tlillltiuli Hf pur id lZt f ~naY1l1 t middotnt r1 lI1 i ~ a hatlltlllI 1IIi11 to 1111 Lx IHtllllH middotIn Lt-anmiddot tIlllunl loy la1 litkh~ omrl t 1) tHul parbuih~ -t B ~ thmiddotfuliufptl ]~lahr thpt tu tt fit t 1 It+gtr-tt1 Jnui~tHn eunttlIt _~rnlitl tl~UP ltakmiddot~~ 10 UddU it~ 1 rtmiddot4~pt~middotK1~r ttakt-middot
bull So 1 gingt- 11 tt-liuin-Iy ltr~pl [lPlItl1tat of iilll 11animiddotImiddot- Eqltrimiddot tIlllll hnnmiddot llOWIl dutr fll llltldllllUU xtlutioH 11pound lnhbll lIl lP-ill frolll IolUlIl ~tlaYlllt tl-IlP by dlt IJwtmiddotlUlmiddot lItlilwd oil Ill 14 - 01
i-mllt 11111- -lwltld hi INd I li~ Ii I TIll lllhtIlttj of Itiu~ So 1 (lltll j thnt 11middotmiddot01middot lttwmiddot to amplil tltt Iollllli tilt art lpdnn ib
IntIIll ll~ i po--ihJI with tI lLllit Ilfltl[lll1t It honld l Plllplw izmiddotl rImt ilt tht h of -allllhmiddot with l lllblPl
~ontlnt of ill PPltllt til lIilll it i tlllt pll--ihl 10 11-middot t(1i Xli L
20 TECHNICAL BULLETIN 920 U S DEPT OF AGRICULlURE
Even with screcn No 2 difficult due to rnbbel tlcrltreCtlltiollS may be ob tl
encountered In thes~ caHeH it iH lWit to parboil the shlub fOL leaf lemonll and finally to dry to about 1 to ~ P(l((llt of tnoiibl1(l pound01 b(~t results jn ~rindillp in tlH hanmHl mill
It iH aclvlsable to provic1l thc hammer mill with a ground wire Hillel the presence of static electric (harges 011 tll(middot partkhH will ealls( Home of these to atlhelc to the inside of tllP (olltailWr OJ lila eallsc OI1l( of till pULticl( to form ngg1(llatls EIIolin lalllpling fl01l1 fhis SOI1I(I mlly be (onsi(h1llbl(middot
A1I10l1g the Holnllts with high boiling point that lIlay Ill IlHld in rubber anal)Hs I1IP Illllhyl n-alllyl ketolle methyl ioblltvl kptOIH diisobutyl (tOIH blltyl tHptate llethyl amyl 1Ittail (middotthyl(middotlllmiddot gly(ol diethvl (middotther and n-bntyl (middotthel (labl( 1) TIHse al( also I(sin 01shy
middotent but th( 1(~illS n1( held ill olution by the rll1)bpl pl(l(ipitant tthanol wll(1 lllbb(r is 1)J(lipitatNI (S(ll tabl(s alldmiddotl) On tIle basishyof the lxpHilllPlltH tll( btsf nil-round lolPlli -rol lS in 111( PIlHPllt method is lt1iisobutyl kPtonc wld(h was not IIltlllllfaltllllmiddotd ltIlling Vodd Yflr n A suitable Sl1lgtstit ute iH llHthyl jolllltyL htolt whi(h is l(porhd as llolltoxit UJ)
Clllos()IY(~ (ethykn( glYlol monopthyl (tIH1) blltyl earlgtitol (di(thyl(ll( gly(ol llIollobutyl (ti1(r)~ and acttonylacetOll( may be used as resins sohrCllts (table ] )
In the earlipr work with (sills analysis cpllosoly( alolle was selcmiddotet(d as a suitable solycnt Aitholllh (ell()~oh( alone is pxc(lllnt its rplllshytiwly gwatlL iscosity 1(I(b to bubbl( formation nft(I (SillS pr((ipi tatioll Thi- increased thp (xperimentnl (LTOI OIl of tltp othll I(sins solpnts tI((tollyla((tolH has the proppry of glpatly lNlulingshydH(OSity 11(11 altld(( 10 othr liquids This sohpnt tlHIeforl wa addp( to ((Uosoh( in slIflici(lJlt tlllIonnl to OPI(0111e the dinieulty On the basis (li~ex)le1inwllts ~ purts oi~ a(donyla((tOlll to I puts of (elloshysoh-f (bolll by olume) as Splldcmiddot(l Thp 01 hel Hoh(nl listed hutyl clLlbitol at l(llst the t((hnieal-g1lld( ploduct uSNl is appal(ntly not as good as eithe of t1w ot1(r two () a (ombinatioll of tlWSt
The SOlVllIts JOI liSt in tumlyzing artifkial lubbel$ hy tlw pr(senf method appllLently (lcllIHl on th(middot kind of llI))(I lIp-ityl (Jxidt is suitable Ol BUlla fi and hutyllthlI for butyllllbbl Tlwse reagents IlLe technical g1lld( Calboll amp CtllUil1t Ch(lllilai (OIP This Hllbjp(( hilS not bepn (XtpllHl(ly illwtigated by till WIit(I
PIIECIIIIJ-
All tlst fOl Ih( adlqlJalY or till IHllipitullb ll(Ollllllentillllll11Sl bl baset] on the plctisioll of tllP final I(snlts oiJtairwd with the methods The )redpittlllts s(1e((( n HpJ (xtcllsi( (xp(IimPlltatioll all HatiH~ factor (Hee fig Hi 111lt1 tabItmiddot (jH) Ext(IIin tllts llllTild Ollt hanmiddot shown that H Hatil-gtflltlOIy [gtIpeipitallt 101 1lIbblI is (li-p(IT(middotnt HzHO (c p reagent nil POll sp gl U-lmiddotJ) ill li-P(l(Put (tinmol by vohmlP liol (tllayul( Ipl-gtinl 1l)-P~ITImiddotllt H)~o ill Hl) by ollln( ii lL satishyfaeto7-y l)lp(ipitunt A solution of 1 palt of H~~o to 1 part of H~() (1-1) iI2So1 nnd abo yarious int(lIlIPdiat( proportions of tlllse suhshystanCPs giyp fait 1(511It8 but with till inlIptl(l ill [h(gt ratio of H~S01
~
bull
bull
bull
bull
bull
RAPID PHOTQlIEfRIC DETEMIlXATIOX OF HtBJER AXD RESIXS 21
to H 20 the )olutioll becollles somewhat vbcou5 and precautioll Il1Ult be taken to ttvoid bubble formation When it i5 poured into tilt Cllvettes
It should be lloted that both of these precipitants have an ftellleshymmiddottion It was found that when XHjOH was used in the rubber preshycipitant in pInt of H~~O~ the readings were -table l)Ut were not reshyproJutihk The lIl of XuOH in pInel of H 2SO j ran nHittble result as a llth H(HY(Pl WIWll til( li-P(l put lthatgtl in lublltl llnalysis or H~O illlP-ius anal)j wn-i uddint(1 thl eharalteliti(s of till liquid with pleeipitated ruhber or resiu in HI~P(ll-ioll n ren1 on the lpNmiddottroshyphotometel m tololinlPtprfollop(1 it lPgnlal lIlll II~ lxplaiHd on pHgP-I (Sl( figs 11 aIlIIl) Tid made it lloible to outain lEPJOshydlHibll tpnlt nntI (onplt1J1(Jttly till JpqnitPIl tlPgJPP of PJPcljoll
IIWIE(TI 1lt COl~101J)
Jtl thp ItJiPl middotxlwlillltnb hefoJ thtmiddot -1l]YIlIt allll pnmiddotdpitallb had lIptll ptoppJly adjutp(l it l fOllll tIuH till llP or a Ploltiw colloid -wll ltIi1)cJ [ttlJmiddotntl- imlIopl tll lmiddotpro]lIibility of the lPlllt JmUkllly ()Ilt 111 U lput lUlU illlihumiddot tOJllPOlUtl tpHd liglyeol teltlut( - llpanlItly IllmiddotlfP(] to lit til I1m t IHflll lImnnmiddott nftlr tlH filial prOIptlllll WtlP dlvPllill1 tlll 11lIlpfit (If thtmiddot [llltlltin lollohl wa Hot 0 natlv I1l(lhmiddotd III rlumiddot Ia- of tmiddot ill tllmiddottJmillaritlu it b [1 hmiddotjlmiddot til IIpoundgt Ir llH1 It liltr ill-llImiddottiT Ina lll ptlPII by it U( in ruhhfl mmly j 11If dtmiddottail fOJ tltt lllllmtlllll If thl plot pet in nlloid ~llntill tltlmiddotlImiddotmiddotlttlatiflll lIOlllllllhtiPI1 are iPllllll page
liTFHFEHliG COIOf
(hi II tht lllail 11111111111 that had til ill -111111 II urklll) om tlH method fot lublJtt tlIlO1 rpir- nlalv~i in plaut llllpll- wa ttl (lilll~ inare tIte (gt1[01 till to tIll ptP-PlHt f xi [aIWIIII- 111 TIlt amount of (olor varip from lUllIt tn -amp ]pplwHlI nlt rhmiddot lt IIf thE Hl(ltllial tllP part of till plllIt -lI11lhmiddot(l tilt hi-tlllY f tlll plaut mtteshyrial ~ub-lltInent to Itlllmiddotnmiddot-rill lliI 1011middotly OrllPI Inlw
In ruhlwr lrtl-i I Iii 1101 au Itmiddot 1Iplll11l by 111[ I--r ratmiddottilt thE -lllll]t with uptoIw or 1middotmiddotlIll-ol - wIdell [llllol- rlll loillriu nutttel autI thtmiddot lpill- Thi- howmiddotvt n(tnll- til lXtla -11gt1 ilt prlJ~edun) In lP-ill ltluay-i nllHufldy tlW[t j 11 1 1IO(PIlln fill the 11shylImya of hlulophyll Hwl rIlI-r middotIOII IHlttlmiddotJ dlH lUtl~ In plltIH withoUt alo aiftIriL till nmiddot ulttrll
111 pllIbIll1l Wi tilmiddotr hId h It-ImiddottHI tht Pltlpll 1 hlitlt lilt tlw tulllWlli tollImiddot uIwltllIIntut -lltUIhorlllllltll 1111 tIll tlettlllliIttwr IIf t 111 lWlrl-Uamiddot of bdt tl11blLlittUhmiddot r [1 tItmiddot preshyj
lipitatifll 1lJ llllllWI atbull 1iI- in III -1nrmiddottIi fHlttalldh nlrillU~ amount rf middotlorilig lIUlttll Iii lhll of ih lltmiddottllllhottohttt~l l~ol()r infrtl Hm II upd 1 rwmiddot tld~middottilmiddottll PlllItlhi~ f it j proYitiltl with tIll lilP--UlY tU(jlIdlllIlml tIltmiddotmiddot lllklllUIlI
EIECTIol OF 1 [EGTH~
-Ptfmiddott ral tracilull ru~lI gtIll fr 1 nllb t ~xtltd 1 lIlt-th vI iobmy1 ketommiddot lWtl rill [ Ixt lttltt ll UttollylaIiIitt1l11I1t~ ~-I itoiu YtHil)u~ typp of ~IHaylllt f i lItmiddot art hraquoil ill fio1ll1 ~l Th~ lp-nlt fill I11oohl uio[1t ttl willlr til tltN- fur rht IUiXtIUt iwliutll
100
22 TECHNICAL BULLErIN 920 U S DEP1
90 bull eo
I shyz 70LLI 0 a LLI a 60
LLI 0 50 z
a ENTIRE 2-MONTH-OLD PLANTS~ 40 b ROOTS AND BRANCHES OF ~ 3-TO 4-YEAR-OLD PLANTSen z WITH LEAVES REMOVED ex 30 a C CURRENT-SEASON GROWTH OF l- )-TO 4-YEAR-OLD PLANTS
20 WITH LEAVES REMOVED
d LEAVES FROM 3-TO 4-VEAR-OLD PLANTS
10 A
0
a Cd 100
b bull
10
80
I-Z 70LLI 0 a LLI 60a
LLI 0 50 z ex I shy 40 ~ en z ltI 30 a I shy
20
10 B
o~__~__~__~~--~--~--~--~----~--~--~ bull350 400 450 500 550 600 650 700 750 BOO 850
WAVE LENGTH lM~)
FJGcm O-Sll((middotlllll tramaniW1IHl (mrpS f(JI (xlmll 11011 n J1ll of jlta)nle tissur ill n 2--m1 Y011111P of (A) Illrthyl ji1I1J1ltsl krtonp 1111(1 (ll) nt(middottQnyla(umiddot tClIc-C(l1osuln a-i
bull
bull
bull
RAPID PHOTOlIElRIC DETEH-UXATroX OF ntBHEIl AXD HEstxs 23
ThE dula Pl(S(l1t(lltl indi(ntp Ihut 101 Illp ulimls llHthyl liohutyl htOlIl (lxtrHts (lI(I r(dolls of Il1Hxi11111III nigtol]gttioll wiH1I all (is-lIb 11 cOllsic1(]((l n1( blhn(11 wn ( ItIl( Its lIO to () I1It~ nlid Ii to Iii mJL
WhllNIS tlw I(gions of 1middottnL(s( light 1lnlllittamp al(l lgtPlW(PIl wan Ipllgtltsnr) to Ii nllt jW) 1I1JL nlld alio Silllill1l 111l1b (n SI(lIlId 101 nc(ton ]altmiddot(fmiddotollp-(llloolp ~ pxt Ill of 11a 1111 t illl TIl( (1101 du( to lolo ill tlw litlltitl a 1Il1 lullll(I tH lPill- hanmiddot bpllI PI(_ ipitated ma he 1((I1((d to fltI ynbhing poillt II ph( illg OJ illshylmiddotJall(( WIWp balld nhm ()) IIIJ1bullbull[1I111 lxjlPIitllll1b Illln -h()1 that Ih( lIIot uilahl( WHYI lHlIJ fOI 1-1 ill 1l11J1l(I HIH11Pill- illllllrsi i-in till IlPighl)()lllll()(l of ~llIl1lt bull
bull UIlIilHlIy of n typhn] lXPllillllllt to )10 l1iP(tiP ((JIlllo( of (ItOIS dul to lOIOl in 1llblnI Hnd Iill xtnumiddott 11(11 IIIIolp t jUl i p1llelll((l ill tub]lL Till llhlllt- 1tpIO]II Hnd ((llll~()h whit-h UI(I ](]Hllilltl n 1I01lllIhb1 01(111 lxt 11111 IIll 1llll)1 nmtp[in I and )(middotills Tid IIlnkl it poiblp nftlI tlIp uplll1tillll or tlll o1PIl( (0 [niH lip 1Iidl1p~ of lI111 11111(( ill lit ll11l1)[1 (llnlIb nlld Ihll
Sl(ll n ol1lliOI with tllP olnl IJllt illiollt HIl Iltlllll llllI (Ill ltllthpl prpipitnnt j Ihll1 nddld OUI ha a lIilPt lP( of till lIiciPlw of WH( lllIgth 7) lUI- ill llilllillatiu (nnl till tll Ixtll1I101l ()lll~
Tuu tmiddot-Elilll IJl flrldillY 11-1111 lrlllI IjfJI til islII 1 1(1 ([rllt IIIIIJIlIr JiIlIt~ if 1Il( Ihll 111111 k til I III Ilrln I 1Intd tf 11111 JiSf fill I I II I tIII Ilf Iilltl 1f1JlIIillII1f I Till 1[ 1 IId 1 (I (middotIt 11111 (I1I1iI1 1lf1IWtlfJlIIllfflr p middottrllhIJ11 II J III 7IImiddotIa 111 111 lilt jJIp 111 wilTII
t~t tnVIli~ ~nn r kn t~ i tmiddot ~~l Jr 1middotmt ltlTt
HmiddotOtt ~I~ lin t I ~ 1 t~~l ~qrmiddotthtmiddotrtwb
Hult-middottltlru t T Hw ullut rHtt~ r II I ~ PH~lllt
A~tmiddottHHjmiddott~rjd rl ~gtllh 1 tn~th~ ~ ~ middotI lt~ b w bull hmiddotth~ 1i~lIhun 1 Ii tnl Illd1 -11lt1(11i lullI lUI tJl ll~ t1~11n( I Ihan1li flfttIJir Ult I Uuhtltt ahuul l(hmiddottHmiddot~t trv r fti HIt lftbyl tlonhUt)1 k_hIl( 2 m~ fmiddotf tuhlHmiddotr In mlth~ llmiddotlf- 1 t r
t r_~ t j
Arhlitlltd ~llIIDHl NcWitn1 ( Ar-(lt()nc~middotttrrtrt ritJJI~ -Iu nllJtl4-middotr
ACtmiddottflnp fmiddotxtrn( ~ T-P511ftf tn mtmiddotth~ 1 ~difmiddotut~ kdn 2 nltt ulruhhtr in Un-tIl lltbu )J~IYt
rUth(Hl~hltlft HhubU
Illlh(I(t tttUtUt hUbtl til J ~jlitl(J Hilllll trtIIImiddotjtl1ll
(UShl I ~tlO wHllolH rulh r (middot1111$0]( J~rru t t )lthyl 15bullbull1middot1101 klll1l
Ili( UHUicbcul ~((i1rUtl ~ulu1iin 1middot lIUIll Ilti lrllltlllt I Ruhhr llt1thuI r1 -1 Irld
ltlt1111Sh 2 nuz f)rruhl~rm nlith~l tu- h f nt nil~middothgt(H] tlrlftmiddot 9lUtirtl middot1 1
rlcltfl( H(l dnllltml it
(IISllhH~rI( Iultruhtr CII05 1v ltTlft I 2 UI~r ublwr In llldh I hlt~1 11) lgtjdvr(llsl~9rlltmiddot middotlmin ~ I~ gt AIHItilltl no IrttipHallr iI
~ Bbnk 10ol m(thyl i~tmiddotut~i kdHn H 1 m1 j~~ l1rH-t lt~tlfltmiddotn sf n it ll HltlMjftr~nol O2~mlJ ~U~1o-ulp ti~tW -xtra~middotl(lt1 ltt 411 ml bull ie f Ct- kft rt t~ tirattJ middott ill r u l1kn ttJt
in metltl isobutyl kNqnf nn~i mljp ur tmiddotmiddot ~oml ~urr tttl i t w ltJj1JH kt 4t 3 nlank 1 mL((l1t~rthmiddot(middot mI mttr~ ~but a kmiddot tmiddotc d 11 ~ gtli~b~ hifIAft- fl~ lL lnti 149
ml8(dlfilll BO bull 02 gm guayule U$Stl(middot xUlClt-l tf(h tft wI n nmiddotmiddotmiddotlgt 1 lznt on tmiddot ~Jt r~1 ~~u~~ H~ iI~ thT
24 l$CHNlQAL BULLETlN l20l S DJltJPT OF AGHl(CLlOHJltJ
In table a is pl(sentc(l such c1il((t edlt1tIHC showing that thc (0101 Ixtrnetccl from guaYIIle tisslIe wit h II(P(OIl( n nd (pl1oso[yc is cll(div(ly sCIe(nec1 out by the s(lp(tion or wnw length )0 miL Oil t1w SI)((IOshyphotonwtpl This tnb]p all-HI ihos thai thl Juhlwl altl(l((1 (nn IJl quall shytitntivcly 1(I(()(Ipltl in tIlt PI(ilIH( or Ih (o]OIplnwPIials and Illsins and tlmt Iuhb(l WtlS nppnlllltly 1I0t (xtltI(((1 110111 11l glll1I1l lisslIt b~ tlHSP SOhlllts Thls( ((suIts ginmiddot (OliIHillg (idJt(( that t Iw IISI of waYl llngth i)ll 1Il) OIl till SppdTophot OIllltPI ii t hl 1101(1 p(oshy(ellule in photolllliTie IlIlalysis of luhhlI OJ l(sin-
SELEGTIO- OF )IOiOCUHO)IAIIC ItIIm ((1111110
On th( basis of th( IPHIlb shoWIl in tabl(l 1 al hlllpls (1( IIln(lp to SPCtl lC the PIO]Wl 11101lO(lIOl1ln til Ii ltlJ ((lIllIJi nIl ions 10 llIiOlS (oIOlimet(Is 111(gt 7W-Ill~ filtpl flllnhwd 101 til( I1~lI1l photoshyplpct1i( (o]oriJl1ltll fol which Ill( (hlll(IlIiitit~ oj t hl Ilda he light ilUIlBlIIhiSioll (t) elll nn -hO11 ill fig1lle 10 iws satlsfa(lolY IPshysultl 111( iiO-mL HitlI olllhintioll 101 whkh ttp (middotIatinmiddot light tlnnsmission (ullmiddotis a 1-0 showlI ill figllll (I is -nthdnlto1 hut this is not stnlHlnld NtllipmPlli
Up to fhl PlPHllt lIS(middotflll pound11((1 (ulllbinntions jn lltl iOO-I11L Iunge hayc nol bllll SlClIlld 101 lhp Klpt 1-1I1l1I11PISOIl (olOlinwtll bu fnltlwl nttCl1lpti 1( )(illg IlIHd
TJIpound OF ST~lmW AFTEH HIIJ1EII Oil HHSIS rlll~CIIITTI(J
~ considl1ltiol1 of ttp lillll of Inlllling af((1 plpeipital ion of 111gt)(1
01 l(sinSTlOIll ollltionis impoltant J(jl~ thC1HI(Plltngp of light IInIlSshy
11 rshy10 f shy
09 f shy ~750 Mil- DOMINANTI
~ 08 cshy I WAVE LENGTH z
I III III i O7 - I III
~06 - 05 shyw
a
Igti= 04 - 720 Mp DOMINANT ct WAVE LENGTH- ~ 03shy
02 f shy
01 t shy 1)O~~~gt~- J 600 700 800 900
WAVE LENGTH (Mp
bull
bull
bullFIGlRt IO- COJllPIUlItiw ~IW(middottltll tlnIlRlllii-lion (II (IllP( 101 1i11(1 olllhinulloll
with dominllnl Il(lllllgths at 720 and 7iO lUi
bull
bull
bull
HAPlD PHQTQlfE1IUC JjETER~lINATION OF Rnmrm AND HEtiINi 25
mitted (spertrophotoll1eleL lCuding-) Ol light (1 (tClcrl (phOlOshyJluol01l1et(L lcndillg~) i~ StlhjNl to (hangl
]fjt~l1le 11 and l~ show that ill til( (asc ot tJaugtIllitteltllight llJHC th~ (x[llliHlllIlnl (oIHlitiOllS tllpl j lilst n dtlln-e ill Pll~(lltngl or UllllslllittnlH( follrnY(l by It ptJiml of lClntin stability with only sliuht (1111 tHn- a f(Pl a lIt1ll1btJ of minutes The light t UIllllitblllll t l(1 ill(Iln~(s This lIIay IJP llllllJltlli7P(ll1 ffl II ow 1Ilt )( f(( darI oliIII tIIlIlNlIlitt(IIIlfJIIlh (iditilIiid Ilil1 pllIipintnl )uoshyIn Of ( 8inx in (~f1( I~iUII i~ Ild stahl I 11 itlll If 1inl nh prlshyilli(ioll of 11l1d(1 II IJIX f) jllIli II (fJJltfiIIlilty slllMI IIriot 1) IIIPldUnl1i tll(I1I rllltltilJl oj tJi~ Jlt jiot IUN ilUf Jxl1 will tIt( tOWI IItlllilil I 1llIlllblJIol I ill I~11l11111 d ill till ifjuids JjOI scnttplltl light 011 till phololltHJIOIl1lttl till dilPCt ion 01 elangl b tlw IPrfIi (If that illrli(atPll rOl tlulll1Jittp(lliuht It Itlll b( llluliJr I-(Pll that if l(middotndlnJ- IIIP mad n itl I t lIP ~()ll1d()lb lpalll this pllioJ of nmiddotlatirp tuigtility tllP llLot tIOllt thi Olll(P (nil bl IPdUCld to tIl lltini III 11 Ill TIll l~adiltg (illH~ bbll Oil tlHl datn rUl lublwls and llsinlt Illl ginll ill tnhh
50 r----------------------------------------------- f shyZ
~ 40 ~----~W~A~V~E~LE~N~G~T~H~7~5~0~M~P~~~~ ~ --------------------=-=-= ~ 30 f- WAVE LENGTH 540 M~ _z _____ ___ -=- __ _ ~ ------shyt ~_=---=-=--I GUAYULEIII 20 -Z HEVEA ltt II KOK-SAGHYZ f shy
4 6 8 10 12 14 (6 18 20 22 24 26 28 30 STANDING TIME (MINUTES)
FIlirtn 11 Emmiddot of wav hll~rh Il li~ltr tlall~lIIit1alHl aftI IUIlItHt -Imlli lug 111m for guaynh llmiddotn 011111 middotiolIlJh~z 1111111 llijlitul1 flolll 1lHlh~ll1Jllryl k11II11l ~(lilltlll h~ lwitlitll 111Inu1 111l~1It1 2)1111 o1U11111 (Helillins on (illllun tlunhll IlIIJlllw]ntllW111 lutl(I[lholtllllltlt with ijUjt Wlnl IHI Ilf1 I
11 EFFEGT OF Hbli 1 -()JXT10~
Tilt lnblwl ~()h(llh pxtnl( till IPillgt ubo It 1m nllu1- bellt -~atea thut ~lll 11-111- tUP olnbhmiddot ill middottIIlIlOl ~1It tlWIIJI( my U)t PIl (tlIHatcl WIth tl1l lullh(t I tahle lJ 1hln 1- -1111 tIll (llllstlOll of nny p()~iblt tITptt of XtIIl11 diflp]lws ill ((JlllPllttUliollS of 1l-in lil lolutioll alollJ with till 1lIltbpl TIU data ill wbh +ho on tIl( hn~is of (olorilllPill ladillU thaI tll( IIUOIl1t of lnbbll Plllipirntld 110111 Ilwthyl olnlld kptOlll olntioll IJ 1li-jHlllnt 1l)04 in 1-llltlIllt ethallol)- not amlll hy thl llllNlI(l of llvin aU1ouut of llins inolution bull
-----
26 rECHNICAL BULLEfiN 920 U S DEPl OF AGRICULlUHE
100
90
80(I) C)
z Ci 70 UI a 0 60 a ~ UI ~ 500 ~ 0 I Il 40
30
A 20
0
100
90
(I) 80 C)
z Ci 70 UI a 0
60a ~ UI E 0 50 ~ 0 I Il
4-0
30
B 20
0
--
--shy ---shy---
2 4 6 6 10 12 14 16
---shy= ~ ~ shy
-
2
025 05
10
15
20
25 -30
35 40
SO
-60
=70 80
16 20 2224 26 26 30
OS
- 10
IS
20
2S
30
35 40
-50
-60 -70 -80
bull MGPE 25-ML
VOLUME
bull
MGPER 25-ML VOLUME
Florm 12-EtTld (If till1l or Slllldill~ 011 light transmittallce (01 (A) gUllyulc lnUIl(I plccipitllitd frOIll llltt h~l isobutyl Ielollt solution Ily neidilic(l ethanul bull null (B) gUllyule ll~illii pre(ipitated flom aeltoll~lllcetOlll-Cl])osolY( 3-7 solushy11011 by H(illilip(i l1U (HPlldillg~ nt -lIlillult Ifllpluls 011 Evelyn photoelectric colorimellr with jU-lllp tlllll alit U-1I11 npN(lle spp also table 2)
bull
bull
RAPID PI-IOlOMEllUC DElEnMINAlION OF RUBBER AND RESINS 27
TADIbullbull ] 4-ReZation of amiddotmount of middottbber pleeipitate(Z Oln metltlIL isobutyl ketone 80lutions by OS-pereent H 2SO in 95-pere(lIIt ethanol to umollnt of resin8 udde(l U8 indivute(Z by colorimetrio readinU8
(Rubber ami resins cnlculntcd on bnsis of amounts in 5middotml ullquuts of extract from 02 gm of tissue in a 2fllll olumo( bull
Hubucl r~cocrell whcll rcsins nddcd as IndIcated Htbbor al1dcd (pllcollt) ---shy
__________bull_________ ~_12rpcrc~15011crccllt 7511crccnt IOOpcrcent
PerCtllt ercellt Percellt Percellt Percent o o o o o) 50 250 263 252 25000 500 500 500 500 700 750 750 751 749
1200 1250 1250 1250 1250
EXTRACTION TEMPEHATURE AND TIME
Typical experiments to detllmine the time required to secure maxishymum extmction of rubber und ltsills at 115deg U Ilre sUlIlmarized in figule 13 the solvents used-methyl isobutyl ketone for rubber anrl Ilcetonylacetone-cellosolve 3-7 for resins extraction-are very eflicicnt since under the conditions indicttted maximum values were secured after 30 minutes of ext1llction The most eflicient liquid for the bath (lig 1) used in extrtlcting rubber or resins is ~ high-grade cylinder oil (S A E ~O) The sand bath and such liquids as glycerol have proved unsatisfactory
RUBBER AND RESINS STANDARDS
According to the National BULeau of Standards 1-_ lhclc Is no gellcrnlly recoglllz(d standard lIIutcrlul [ior II rubber standard] The rubber hydroCllrbon ill llifferent samples of conmlcrciul smoked sheet or pale crepe from heclI pluntlltions nries from l~ 10 04 llercent of the totul nutletmiddot the most 11Ioruble conditions Of preparation
McPherson () has described a procedure for the pLeparation of pure heve~ (Hevea brasiliensis (H B K) MueH Arg) rubber from crude rubber or latex In the absence howevcr of ~ generally recogshyn12ed stalldard for rubber hydlQcllrbon [caoutchouc (CnHUs) xJ the standard adopted was that of the relnthely pure product secured from gunyule tissue txtractiotl nccording to the Spence-CaldweU method (5) or the motlified PIOCCdUlU of Hohnes lind Haasis (p 2) The details for constructing the calibration CULes are given on page 10 Standard rubber samples apparenl-]y can be stored for a long timc under the conditions des(libed on page 10 The duplicate colorimetric lendings for glULyule rubber newly extracted by the modified SpenceshyCaldwell method were ()J2 ench as compared with US) each for the sample extracted by the same method but stored 1 years In each case colorimeter rcadinllS were made on mixtures containing 2 mg of rubber in It 25-1111 Yolume
The selection of tt suitable standurd for guayule resins presents some dilliculties Tll(~ acetone extract of gUllyult estimated on (l gravishymetric busis~ for instance proved to be variable depending on the type of tissue sampled or season of sumpling because such fractions as
COllllllunlcntion dul(lt1 Octohtr 22 11H3
28 QECHNICAL BULLEQIN 920 U S DEPT OF AGRICTTIIlURE
16~==========================115 shy
14 bulli= 13 z ~ 12
ffi II Q
10 c w 9a w
8gto () 7w a
6a w
5en III ) 4 a
3
2
A 00 5 10 20 30 60 90
14~------------------------------------------- bull13
i= 12 z w II ()
a 10 w Q
9 c w 8 a w 7gt o () 6 w a 5 If)
z 4 If)
w 3 a
2
o+B~~__~__~____________~__________~ 5 10 20 30 60 90
HEATING TIME (111 NUTES)
lllGUltE 13-lDffect of time o( lICntillg O2-gm samples of gunynle tissue with solYlIt nt llfio C on lo(OVl)ry of lllhlJer alld 1Isim Lt HlIhblL extracted with methyl isohntyllwtone B resins Cxtll1cted with aCftonyla(etonc-cellosolve 3-7 bull
chlorophyll are weighed along with the resins in the acetone extruct but are not estimated by the present photometric method (fig 0) 1he use of a diffeJent stanclttrd waS therefore indicated
bull
bull
bull
RAPID PHOTOMETRIC DETERMINATION OF HUBBIm AND HESINS 29
The resins standard selected is based on n relatively pure source of resins the rcsinous exudnte 011 the stems of guuyule plants IJldimishynary expeliments with the resi nouS cxuclate from diffcrellt gllayu Ie strains of various ages indicatc nHlt there is little YaLiation in this subshystance on the basis of Colorimct(r readings 011 2-mg aliqllots of 01shypercent solution in It 2i-ml volume (tabl( li) Expelilll(lnts have shown that the air-dried (xuclate contains 3RtOH p(Ic(nt of -volatile matter This material is l(latiyt~ly stablp ill (OlllpoBition and is npshypurpntly on ly slight ly hygroBcopic as shoWIl ill Ia bl(1 1 Tlrp Ipsinolls exudate may be jJleplpd in two wayi-i fl liSP as a stallClHld-(l) the clpan exudate is clripd iol Ghouls at ()1deg C at W indlPs of a(lIum Hnd aftclbCinOglOund ill a molfalis 1)I(spI((I intn airtight COllilinel OL
(2) tllP Cx7lclate is clissolllt1 ill a(lhllll and filtplpd PlactieaJlyall of the acetm1l is thpn lYapolntwl olt OPI a stlam or atCt hath and Ow residue is dripd ground an(( PI(sPIld as ill tllp fin lllethocl Tlwse two prepalHtlolls a1( (ompalpd in ta hlp ) 111( (((tails fOl ~t()lil1g the resins standald and (onstlllcting the calibration CUITPS alc given Oil page ]2
lAIIIg fi-CUIIIllrsoi (lJ lIr-dr(1I IIIIi 1((11 II II-()I-tr((l l(sil~ 11111111(8 of I II 1111Ie
[Colorimetric rrndill~s 011 1~I11 phulll(Iclrie eolorillJct[lr with i~()middotmll (100- to iiOIIIIl) fillcr [lnd 5-1111 lIperture preeipitantl part ofO5middotPIrctllt 10 to 5 paris of IIOj
nupliclllc(oloritwt([
nIl(lin~s (hIlSlcAg~ ofSlmillXo JrNliltlCllt of fPsiJI$ L1Xtlrlntp on 2 IIIg ofplanls fllsins (XIHIIlt~Jwr 25-1111 vol
tII1(1) 1
leflTs Various _ bull ____ bullbullbullbull 3-9 Colll)Josiltrlairmiddotltlricfl bullbullbull nf)2 002
])0____ bullbullbull _bull __ _ bullbull ~-l Composilld (ri d at n5 C in aUmiddotimh lWUUllJ for l (jOuj(ja hours])0______ bullbullbull __ bull ___ bull 3-0 COJIlpositld disso]NI in neptolll f1l1erNl fl(lf()ll( GGO i(jO (Ivaporntld olT OV(1r Stpl1l11 halh TesidlH drl(ld I1t fi5deg ( ill anmiddotinch VIl(Unlll for 0 houlS bull
middot106 __ bullbull _ Jir~c1rild_~_~_ _~_ ~_~ _ ~ ____ _ __ _ OUu GOifina_~ ~ _ ~~_~ ___ _ _fln~ ~~ ~ ___ ~ __ 6(imiddotI tiliA H)[_ ltlu bullbull i18 tisSflOabullbullbullbull__ bullbullbullbullbullbullbullbull lt10bullbullbull _ tillO llitO406__ bullbull __ bullbull __ bull __ __ lt10_ Utl2 fon591_ fo__ bull liGa oOa 406bullbull _ __ lt10bullbullbull_ li5S OM
j Ph( vnluls in Uw Inst COIUIIlIl indieatp thnt gunyulp fesinous (IIHlnt( wlwtlwr dfircl hi Yn(tlLJ1l1 wilh L~ perc(nt loss of volntllt wutl pr or tWl c1rild giVPd npproxil1lnh1ly t Iw snllw colorinwtCr rNHiing- 011 till busis of aliquot~ cOlllniuiug 2 IJI~ of flsillS lXIHlntp l)tIf 25-mI volultl( Ihil- illdicate~ thl11 Uw UITW IJ1flS~ of olnshytile mntl(f prt~(iJlitnt(d gins npproxilllntlly Uw $1II1l (oiOfirnl1tlf ftudiTlJs ns tho ftsidtw A pnlill1jllaf~middot (XIlltrinllnt indicutls thlli th VUllltill muller l(lIlSists of thl Ilrplne oil fmcl ion I5-(1Il gtnplls or rlsitlOtlS (lxudntll gnvll by stPll1U distillation nn Uefllgl of 011111 of jl(lfPlIW oil with npproximHte tilllsity (If OHIi lind lhus rrprlsll1ll( IlPIJroximllt(I~ 01 Jerccllt Of t he original weight 1hls lllrClnlage complrcs wllh 38 llltrC(ntlost by drvinI( in IICllnllJ
aSplusmnUH perceilt or orlginlll weightlosl
The wailnble illfolJllntioll on tlH (ow-JitlPllts of the gunYllle r(~shyillOllS exudate alld tl1( HeetOlIP ext act of gaylp ti~slw is sllIllmarized in this paragraph lYalttI (u) alld also Hangcn-Slllit lind his coworkshyers 16 reported that 20 percent of the resinolls exudate from gUltyulc stems is parthenyl cinnamaie (CHuOH=CHC020 11JI2r) Steam disshy
15 (OIlIJIIIIUicatioll flom A T Haai(II~l11it llId (0011(11 Calif0111 ill Tnfiitnte of Tccllllology Past(IlIJI Jhps( wOlken al Htud~ing the COTlHlitlllllts of the acetone extract and other conlltituellis of guuyule
30 TECHNICAL BULLETIN 920 U S DEPT OF AGRICULTURE
tillation of similar resinous exudate in the writers laborntory has yielded approximately 4 percent of the whole as the telmiddotpene oir fracshytion Haagen-Smit and his eoorktrs nportec1 thttt about 25 percent of the acetone extract from guayule branches is parthenyl cinnamate and 6 percent of the bark (ltortpamp-phlotm) extraet is parthenyl cinshynamate These workers fm-thcI reported that 25 lwletnt of the nc(shytone extract frolll bLllllches is a compound with the tlI1pilicaL formula CBoH400a 1 percent is a compound llwltillg at 2P to 2T5deg C and 1 percent of the extract from the ]eav(s is tl (olllpoulld nwlting at 100
to 1710 1Valtei (6) reported that 3 to -l perc(nt of the tI(eton( txtract
of leaves and flowering StPIllS of guayulc eonsists of waxlike substances soluble in olgallic soln~nts but insoluble in at(l and (on(ent1llted H 2S04 The flactions mentioned on the basis of (onHLTutle esti shymates of amoullts actually isolated tlecoullted for about H ptIcent of the totalncetollt~ so]ubles extracttd from tll( guuYllle 11 rub The other constituents ltlilaill to be i(](ntifi(d
RUBBER AND RESINS CALIBHATION CVHES
Typical culibndioll Clllves iol Iuhbpl and I(sins bas(d 011 (ldtLminttshytions made nccoLdillg to the plocCdmC outlin(d 011 pages middotb to 1G arc shown in figulPS 5 and 1+ The spCdlopliotoll1lttL en (OIOIjlllctCI readings are plottCd on s(lIlilogalitllllliC pappi ag-ail1st (Il 11IbblI (011shy
100 ~ 90
80 ~ 70 ~
z 1amp1 0 II 1amp1 IL
1amp1 0 Z
60
50
40 ~ltI 30 ~ en z ~ ltI II ~ 20 C) ~ oJ
10 o 2 3 4 5 6 7 8 9 10
RU8BER IN 25-ML VOLUME (MG)
bull
bull
bull FI(lURE 14--Ctlihration curve fotmiddot gllftYlIlc lubb01 (Hct(lings Oil COIPIIHlII tlOl1hl(
monochromator SlCClrophotolllet(r with 7fiO-11IL Illtel alld Hllp Wll ( IHlll()
bull
bull
bull
RAPID PHOTOMETRIC DETE~MINATION OF RUBBER AND RESINS 3]
centrations From a casual inspection of these CUlTes it would appeltr that Beers law does not hold Actual tests indicitted that Beers law was applicable only within a narrow range in the upper portion of the curves The analyticlil results on the basis of photornetric readings nre therefore calculated by direct reference to calibration curves or from reference tables of equivalent values bllscd on the cnlibllltion curves
Calibration curves for kok-saghyz alld heyea lI11tulltl rubbers and Buna S (GR-S Chem Gum IV Goodyear) and butyl (GR-I Standshyard Oil Co Protoc) sYJlthetic rubbers are hOWllil1 figure 15 The samples of kok-saghyz rubber were furnished by the Diyision of Rubshy
100
90 ~I) ()
z 0
1amp1 a
~ a
80
70
60
s 1amp1 ~ ~ 0 ~ KOj-SAGHYZ 0 l Il
50
HEVEA~ ~
40
100
90
~ 0 80z Q 70a Co)
a 60 ~ 0 0 x 50Il
40 ~----~~----~------~------~------~--~ o 2 3 4 5
RUBBER IN 25-ML VOLUME(MG)
FmUIlE 15-CaJiblation curves fOl kok-snghyz h(YCII Bunn S lind butyl rubb~ls (Readings on gy((yn photoelectric colorimeter with i20-lIIp filtpl and 6-ml aperture)
32 TECHNICAl BUIJLETIN [)20) 1 S DEP1 OF AGrnCUIlfURE
Iwt Plant JIl(I~t ignlioll of thi BlII(un and (1( l))(parcd according to 11( SPltI1((-Culd (]] (6) PIO(((lllll Hlpt pal( CLPPe was (xtmch(L with acetone blI()Ieit W 1I(gt(11l a ttnlldal(l
SEXSlllVllY Ol~ llETJIonS
By lip pIO((l(II11P olltlillP(l 011 ]Hlg( +n Iowa (lOOl IIIg (11 1111i(l0shygmm (gHlllllla) of 1hblI ill a 2)1111 yoltll1ll (all )(gt dltpltld Oil tltl Col(man (lohlP mOIlWhlOl1lHlOl l-I)((t 101 l1lOt 0111 ci( I ill1ilnlly 001 mg of Iublwr ill a 2J-1ll1 n]ulllP Illay bl Ilad Oil till EnI)1I photoshyllectlie (O]oLillllt(I Thll ya lllll- 011 tilt IHl-i- (J I (xl ad iOI1 fmlll 02 gill of til-lI tH(JI(lillg to tllP -lllndal(l jll()(pdull 1(PIPStlIt IlO()2J tlnd 002) P(IT(lIt of llIbl1ll IPI)(((inly bull1t1lollgh -lI1t low allils can be d((d(middot(1 il lIoullt1 Ill IPtllizpd thnt till PIIOl ill PlI(Plltng( or tll( al110unt dltlIllIilll(J i ltlatlpl high ill tili PIY lo Itlllgl 111 aetllllllladie(middot Ill( lopl lillliL 111)(1(1 lIw (ollllil ions of tlil ]lI()(lltlIIIl u ol1tlinpd ipt at l11 11I1 or 1111gt11(1 illt i-1ll1 Ollllll IlPIPltPlltillg 01 p(gtl(pnt of JllUiJtL un tlll 1Hli or (xlla ion rlOI11 II rlll of tisSIll
EIlIlOH COSIIlIHIIO
In Oldpl to H(IIp ill )1lHtPltt pl((iioll illlpIi1I- it i lH((SSHI to slnlldHIdiz(i rigidly 111( Pl()((dlll( 0 illdi(ntpd Oil pnglt- - to J( If lids i dOlH tlip lXIHlinwnlal PIIll is t(middotdllld 10 n ndninlllill
Illlt pl(iioll of (hI ]lIPPllt 1IHllwd Oil til basi of ]llllP llIllJt1 alld Ipsinssollltions call hI jlldgl(J 110111 figllll Hi lileh lio- til HPIlIgl d(intioll oft -illgIP lI1lnSIlIlIIIlnt in lHi((lltagl of Ill( alllOllllt 01 Illhshy1)() 01 lpsins d((PI1I1 iJlld TIl( (1101 PlI(Plltaglt H1( gi (1 101 OJ) to
RUBBER IN 25-ML VOLUMEMG) 004 01 02 03 04
i= I I IZCtOW
fbA ICtU CtCt WW a
01 02 03 04 05 06 07 08 09 100 = RUBBER (PERCENT)
RUBBER IN 25-ML VOLUME (MG) 10 20 30
~ I CtZ
bBOw Ctu CtCt Ww o I~
010 50 100 150 200 250 RUBBER (PERCENT)
RESINS IN 25-ML VOLUME(MG) 10__ __3-0_ 40 50 60 70 60 90 100--_-- 2_-0
Ct~ -r- 1 I OZ
WCt UCt b C wCtW
a o I I 150 250
RESINS (PERCENT) o 10 50 100 200
bllI 1tI W-Yllnl dtd1 ioll I I 11l1 11IlI11 1(111(11 1 III Plll- IlIIIlol1 01 IIim~
bull
bull
bull solution Il basis J o golH of tiSSII (JlILCl-nt (11(11) for (~I) (l)1 til O 1I1
of luhllpl lin 1 III I (I Ill of lUhlJPl nllll laquo I J to 111 nlg of IlSlllgt (Itllillgs on ]iYllyu pllolwh-llrk CO[IJlilll(-(PI with nOHIP Iiltlr lIntl U-lIll allcrture)
RAPID PHOTOlJElRIC DELEHlllNAllON Cn HUBBER AND H1~SINS 33
10 mg of rubber anel1 to 10 mg of resins in a gJ-m1 yolumC For
bull
bull
bull
comparative ptuposes the leslllts arc also calculated on the basis oJvershycentage rubber OL tltsills in 02 gllI of tissul As WOlllL be expcet(d the error increases sOIlHgthlf for 1(lali nmiddotly low COlHell t1llf iOlls oj rllbbeL or resins The curves in figure 1(j s1l0 that ill til(gt Illlge Ol to 10 pCrshyeent of lubber the elTOI rangts Jroll1 abollt Ll to II) ]IlC(lIt abo(~ this mlllc tIlt (ITOl d(((ts(s to (ollsidlItbly ltmiddotss (han 1 1lICPllt of tlH mllollnt ltl((Lmill(d Hil1lilally in tlH (lISl of l(sins analysis (fig 10) the ltLTor is (onsit1eIubly INS than 1 PlLllnt ill (he lallgp of 11 t~) ~() penPII t
In nil ([lSl of lllhblI alld (sins lx(Inltpd tIOIl1 (issups Ol addcltl to tisslle lxtlads (s(( tabhmiddots (i H) illyolillg ll01P o(lllntiolls the eLI01
is hig]wl thun that indilHtld in figllll ((j Im pUIl Ill )])p I tllllllsins solutlOII
COlllUCIIOXFOH IXSOLl-IlLl~ Ilgsqgt(Jg
111 th( Jllo(pdulP ollllillPd 011 paw I till illsolllhll isSII Ipidll( tflpl (xttlw(ioll is (Ptill tlw lIask l(lll till xtlct i l1wdp up to yoltlllH It is not rOllPllipnt (0 IPt()PI qWlIltitati(Ir III(lw[olH a 11(1 pllooll extlnlfs of guuyull I is-lll alll thl1l main t11l111 up (0 YOIUllllmiddot bpCaUHI sllch all additiollal stltp wottld]) tillll-C(JllS11ll1illg Th( Iogiea nll(gtIshynntin is to mnkp tltl lXtlUCt Llld Ipsidup lip to OllillH in till original flask andi llPSStllY 10 llwlno tl OIIpdioll wlHIl (allIlnting [hc llshy
Hults f(JI [hl oll111lC displupd hy till ins()lllbh llsidll( III it l)picat (IXpednHllt (ollsisting of Jhp lppJiea(iolls if was Iollnd llftt at ~iiO ( 02 gill 01 Iuhhll pillS IPill-fl(( lisslI(gt (lollpdll fot llwistUlC ou basis of dlyillp ut lOW 101 ) llOlll-j (lbp(ld only t~ llllUll voiul11P of OOk7D~- OO(lOO(i Ill of lllthyl bolnl(yl 1lIOll( (lplhlli(al-t(Tnltle sp gl () Ii I ll(Hli (j at ~)) -gtitllP tl1(gt 1It101111( () r t is-lIl xt Iadld j sl1lall til( PlIOI dul to Ill(gt insoll1blp Ip~idll is slllall III [0111 ill( wOtk it (all lJp diIpgal(ll(l
]hcon~lIY OF HllIllgl AiO HESIS AIH)gl) TO EXTlIACI OP
GlYlLE TISSlg
Tnl)ll G L(IHpslntillp (ypi(nl llld(~ SllOS (hat all a plngl of HIOK PlI((nt ot lltl pltl( Ilhl)(l acldpd to tllP Itll h iolJut1 InmiddottcJllP xhnet
of guayulp tiSI1( WllS 1l((PllIl Tlli nllintioll flOlll (olllplpU I((OYshy
PIY i within flll pxp(IiIlHuttllIIOI ~illli]llly fnbll Ii llows thn 1111 llYlIUgl of 1O(1~ ])(I(Pllt of gllllYllII 1(-i1l- add(d to II( (pllosol( (xshytrae of IUllY]l t i~HI Is 1l(oPIPI
THl~ (~ Hf (Off Ill of 1111)( J OJ I~il~ lItfI(( In ~(JI1IJk~ Ilf (111 [lI1Il fI2 lIII
0 tlUfllllit i~~I1
Instrument
---- ----~---- bull shy 1(1
Colemun ruono~ltrOUlllt()r 2t) II sJl~ctroJlhOL()lIIeter with 2tJ I iflllllI wnclength Fetting 21 II nntl 0-1111 WU HI hUJl(L _ L U
Ill 7Evolyn photo~lcclrie (olor JU [ imctcr with iO-llIl filler IV (I
H1 0 t I I
llImiddot lUn WII 1011 HIO Wn mil lUulon
10 JIg1111 IUI ml lUl anh Io aLn 111)_I ) III li lU It 2) deg wn2SU DD
Irl JIll II IIr II US II
1110(1 lULa lUI IlK) IJ WU
I( llI Htl tNI 1(111 2tlNI HI 0 221) lllil t2S 0 1~ 10 1~13
In (I 2117 I
10U 1l(J ~ 4 _H_j ___
9middotJIlJ5 10115 10 00 lUU5 flUU 4li (tl03 9(11)
leIlKl 1l~)5 lOOU l1KIr JOIS un 003 OIl Ii
34 lECHNlCAL BULLErIN 920 U S DEPT OF AGRICULlURE
COMPARISON OF PHOTOMETRIC A1D MODJIoIED SPENCE-CALDWfLL METHODS OF RUBBER ANALYSIS
Guayule samples were analyzed by the photQ111etIic method and by bull the modified Spenc(gt-Cnldwell mcthod The values in table 7 represhyselltativ(I of typical results indieate It -atisfactory dcglpe of conformshyjty between the two methods in thl range of tiSSlHH with llHHC than OJ) percent of rubbtImiddot On the bnsis of the amounts determimd the results in this runge for the plmiddotts(nt lIlcthod ayernge apploxinHltely j percent highcr
~LAIII~ 7-(oIllJl(i~on of lltlllrIic (IIri mOtllinl SJl(II(r-(ulri-wall IIIrtlwrl~ of rlrrlIIillillfl 11)1)(1 COIIrll of UI(III
1 Flowers frllm amiddotmonth-oltl nursery plants
YAIIIATJO- OF SIli(LE DETEnt1NATIONS Fnoll TnEIIllIEAN
Rllbbel (Uall8i8-Thc plcCision of thc pLcsent method when gunyule tissues Hr( nnnlyz((1 for rubber may be j udg(d flom I Ill datil presentcd in table H TIl(se dahl -how that thl pplCPlltag( uriation of single determinatiom from nwan yullles with low standllrd enolS ranges from less than 1 to 4 p(gtrlent
R(8in~ wWlsi-r-s lndi(a((1 011 page ~j he INntlts s((uled hy the present phoolllttric nsins llHt hod are not tliltly (olllpalable with those of the grtLVimetri( ncetol1l-cxtlt1(tioll II1etho(l Thjs made it necesSllry to selc(t another lalibllltion staudud-tlll Ipsinous exullate from gullyule shrub-thut gies relatively COllstlllt photometric readshyings (table 5) The resin (olltents of guayule roots branchcs or leavcs usually ran(~e from about) to 1-1middot pelcellt The ple(ision of the present methotf WhCll gUHyule thslllS lIe analyzed for reins may be judged from the datalHmiddotpscllted ill table 9 1h(se data show that the p(lcelltage variatiun of sillgle lhmiddott(Lminntions iLO11 meun ynlnes with low standard NTOrs rangcs from about 05 to 4 percent
bull
bull
bull
bull
bull
RAPID PHOTOMETHIC DElEruIINAlION OJ RUBBEH AND HESINS 35
IAIILE 8-luriation inclieute rubller (mallSM of [1wIIle tissue bll thc 1111O0Illclc metwII
Vnrlntlon~Ilbher I (rom mean
ierCtnl Percelll ~OU -22 ~ 25 +27 ~ 20 +18 ~UO -22---------1_______ 51110 0G6 bullbullbullbullbullbull _bullbull
10 ro ----=ii41075 -01 1000 +11 1010 +13
rlln HI itil 1l9~ 1_ ___ =-~~~
115511 ~ US -111 III II 1575 -13 115 b tiS -I a 111 h WlU +22IIM-(middot bull 11K -1Ja Illi c 1000 +03 1J5H1 W +l)7 ll1imiddot tl 1575 -13
Mcnn 15951 131
1102-11 21fJ() +21l102-h _ ~~)SO -17 1102-c bullbull 21CO +21n02middotd ~OIiO -26
2 r~plusmn Il~ 21151 261 I -~-------bull---__ _~~_~______l-___--_
1 lhe$ 1111($ I1n (or SlIlIIllltS Stpnnltplr PHrilClld IIrtlrdlng 10 1hr prollIlIlr( OIiIIiIl(o(I on Imgt$ 4 to IC ~tcond nUlI1 hlr r(J)[ltnts stl1ndnnl llrrot of tilt 1I1(1111
1_1l1~ n-J(lri(iot in relli(Upound rpoundsins (lllalIsfs of VIOJII( lixsue b1 the lhomillric lII(lloli
-- ---~--- - __-------- shybull I I I I Varlgttton
_________~___ ~~lu_n_Jl_Q_~~~_____ ______I__~_o~S_J frOID lDean
Percent Percentgt458-1 ~65 +41IWtl-li 130 -a2Hli8c aliO +26S41i8-d bull 130 -32
1(-011 34I10Olifgt __ bullbull __ ~--====
li-9~2n 881) -06 li-9~2-b Si5 o ~HH2middot(middot S i5 -6$-H2middotd 000 +1
8851 054
O i5 +6 9 i5 +6 950 -20 U75 +6
H-liG3o-n bull -1 n-li6~b bull __ _ -IH-IWH +4H-l61511 bull -1
1tmiddottlU
62~-lI __ 62~-b ij24-( bull OH-Ji
(-Ull
I rll(St oluls nre tor separately ~xlrflCled SllllllllCS IlctOrdlug lO procedure outllned ou pages 4 to 10 i Secoud number r~prtgeulS stulldMd error of lIe menn
36 TECHNICAL BULLETIN 920 t ~ DEPT OF A(]RICCLTCRE
ReUUER A~ALYSrS I~ CRCOE-RcuUER PROOCCTS
Sew rapid photometric m(lthod~fol the ddellllinttion of rubber and reii Hi ill uaYllp ti--ut htp lllell pIPHnl pd oil pag( ~l to In A brief H1111111tlY of It similar rnpid llHthod fm 1I1hb~rllnltlysis of u1lulcanizNl tlIldp lubbll pl(Hlmtlt whielt i~ bn-(tldo on the prill o
ciples dehtilcd tlllLe follows Duplltate nt-gm sllmph of the finely cliyiliNl IlInttlitiup wlirllll out [~ei-()l (all hl lIf((tinmiddotjv INd to lt1iyidl till alllpl) TIll kltolll-olubll portion of till )111(11( tlrc di-olved a- indh-Htpd fot thmiddot lllnkill~ of -tlllHlunlluhhll olutiou Oil Pt 1II hut tIl IUlIp Hn lIn l-fplImiddotd 10 lHI-ml rolllllltti( fln-k antil1ltld(lup to Olllll1l The bnlulUp or till JllO(ldllll i- thatutlilllll on paWs -1- 1 IHI Ii 111( 1(111 1- nIP IXPIP--pd nil til IHi or Iw oligiJla w(lullt of I Ill (I11l1p-I1l11Ilt1 1)(0(11(1
Hupitl PlllimiPJojgtiWllllllllh llIltllOd~ fOJ Ihl llPtlmiddotminntion of ImiddotUlJbll tlnd 1(-illo- ill -111111 Illllph of gutlYllll tiUl IIll dl-eli)ed 111() IlltlY d~o Ill nltlI1lld fOl III Iwl Illhlwl- and l~iJlmiddotb(lLiJlg plant TIllt l[Olllhup hns nlo b(l1l ntuptpl fot IIH lltlIll1illtltioll of lllhbpl ill 11lHhrublwl Pl(Jdlld~ HIIl 1111 hI ndaptld JoJ IIll ann lysis of ynt1J(gt( ic lllbbl[- The llllthmb HIP 1gtn(11 fill tIll fol1owill plimiph- III Grinding
tIll PIOPlly driPl t i~lIl 01 Ul tillg tIll pnHhHt to tll l((lllilllllh~lel of filWlH-- til plllllit qIHlIllilnth( lXIIHtioll 01 IIlbhlI 01 1(--IJl- () llsing oXWllutld olnuh (kttoJls IIt(talp and() fllltil for LIbbel and IH(ltIlIlyptIJllIllIoolYlnJld-o flJllh 101 niJlsl with t(lathelr high IlPililig points 111 to n C) l]olle or in mixt tIll thllt Pll mit tlll rnphllxututioll of luhll(l OJ [middot(ill ill ~() to (l mi1lutp It r(latiwly high 1lllIllllltlltP Ill to 1~11 ) l) lllllipitntillu till luhblI OL Imiddot(ill frolll aliquot () f till oltn ion I IlIlllI-i () f Hlltabhmiddot pl(~(i]litallt (willifhmiddotd lthmwl fOl IIlhlHI Hild llitlifild lllr fOJ JP-illl t~) IIlHkillphotollllliilPIIIIiIlof PlllPlltal of liht tLaIlS mittUl(P lIftlI IlIlbll (II Il in PIlipitalioll 11 II WI( Iplllh thnt (limiJlall till PIIOl dill 10 xtralllOlh (0101 (till dptl1minntinll Iph jill 011 tIll dtwlopllIlJIl of H HIli rOI1ll tlllbidity 111 hpl than I (olot rI
jJlIlpOP-ofallnlyi-I ( p(lllil1thb IIllijOI1ll turbidity or 1llt[lIinmiddotd d(ltl of jgtIp(ii(JlI l)~ lIltlkillU tIl plllltollllmiddottri( ntdillU al tandinu tiJlH~ (dlllilll wlli(h IhlllH(lill-- IP 1llutinmiddotly tnhll) t1ll1t an hlsl~1 oil the (oJlItlIlllItion of IIlhlHI Ill I(ill (lIPIipitat((L
TIll -I(p ill till jll()(Plhul HIP 1-- follOylt (1) 1l~UIIL uJ1lplls of thwl UJfJlllHl (II tliddl(l HUt dlipd 11Illtplial an lXIllltel with11 Ill of till nlnll ill t (oU tlllltIPlll[gtPImiddotatlup oil Iath at 11 Cbull fol 11 minutl I) iIP1lIin(middot(lohd til( (XUtllhllll Jltldl lip to It middotml ynlmlll til( (nlifild by (Illlifllgiuu HlId thlPl IlI nliql1ot of tIl (IalioPlllxUlltl nll Uillltlmiddotll(t to l-llll OIlIIlIllril fiuk- (1) For a trial Ilnditlg 0111 III tlll j liJmiddot~t IllHII IIjI to Ohlllll with lilt Pll shy(ilitnnl a 1(11 it 111 (Dod fill llli lIut ( ptotoJIIltlil IPtlllillg-- of pllllntnl or liuht tlUtllIlillal(I oil n (lpel OphotnJlllllI at rase hng-tlt (If 11 llJ Ill Ol It lollllil1lPtImiddott lloyidld with tIll P10]11 I 1110110shy
Ihlolllltt hmiddot Ii1llI Olllhi lIatioll for -1IpItillg UJlproXilll1l tply Wtl P ]Plwth )0 mp are HHlltk TIll Illldillg lliJtaillld fol tIlt 4-milutl tliall(~ll-
bull
bull
bull
RAPID PHOTO~IETRIC DETERIINATIOX OF R(BBER AXD RESINS 37
ing are referred to a table of equhmiddottllut~ previously p1(pa1elt1 on the
bull basis of 4-minute reac1inJ~ for tilE nmge of lot1telltlatiol1- of rubber or resins to bE elHOlll1t(led tmd gidn thtmiddot -tnnlillfr tillIP fill rUbbEt or resins aiter prE(ipitlltiol1 lwfolE photoIllNliI j(tltlill1 un IUade The r(middotnmining dllplllatt aliquot lll then HHllil up te ol1l1Jle and lpoundadillg ale marle ut the -tandillfr tiUlE iudklltll ill rhl tall1lmiddot for the final r(adillg~ -1) 111( milli1lnm or p(tCPlltllt- of lllhbpL (II 1(-in pr(s(nt are rpadholU a prlpan(l table of lquiltlput for tlll photoshymetric readings h1~l(l ill pnell e1-E on pxpPlilmlItal lhln 1111(1 u-ing as stimtlltlds pure luhbll in 1l1bbtl milllYb aIHI guaYllh ll-ill- lxIHlatt~ in resins detNIl1111lttion I
LlTERATlRE CLTED
(1) lUnSbull 1fl36 THE mURMIXTIOS IIF IOTA RE I III OOl THER llT~II
F1 bullrol IlY U(T1l0fll UfSlfi ~rrnrl r flm lt1 KEYS TI Bill Chern 114 44J-l59 illns
t1 ~ICPHHlObullbull T 1J3bull~ lUTHOO roa THE PtRInCAnu Or a(lIUl IRrIlHU It of TIn
PLRIHEU Htllllflt [ i Bill lallllall 111 Rmiddot 711middotj iIlus
I ) RHBERG P B Ul5 A METHIlO Or ~u(ronrll-nl Hi tIII rUIl[1 f71 ii illlI
bull 14 Hoss W flbull and HARDESTY J O
llH IR1ltDII Of HfITilIZfmiddotR DllIJS ltt 1 Yl fll Off gI bern JIIIlI i ~middotmiddotlf IIl
101 SPEltCE D nnd CuoWELr ~I L 1933 DETER~n-ATIOo OF RtBBER Ii nrllllpoundRBfR Iusr 1uI II1 amI
Em~ifl cttIliIa~~ r Ell i 71middot7i l11 (HI WALTER E D
1U44 ISO~nlS OF PRTlltSrr 1trHpoundV bull l UI n W lHHt (Tnmiddot 1ETS FROM GiYI l~iIl lItr Clttrn SII J UI titJ middotn9--C1 ilIu
17 J YOEbullbullr H lO~( roLORIlETRT 771 IPmiddot nl -W Yurk f H Plrwptric hmica
naly-II rimttry lUll XphHHlnmiddot~ y 1 1
11
HI) ~ fPHELolzTRf 57 111bull Lin xw Yk t H lt PhmeHt CblUlmiddot ila AnaiY~l~-(H lithrry and XIhmiddotILpfIY Y wirh enomiddot rrJlllrjr hy H KtlJnJU11 I
t~1I --- and ~ARVER L 1f41 nlua-w ~in L liLhr IS IP ll~ XIW Yrk
bull For-sale by th~ ~a~fr1nt~nf1ent Dt~c~~ogtnts-~ s t1i rArnn~ut Pn~~~ tJffieshy
Washington 5 D C bull Pl lU ~nts
4 TECHNICAL BULLETIN )20 U S DEPl Olr AGRICUlllURE
zene The solvent 11ethy1 isobutyl ketone on wl1iel~ most of the experllnental wod WJth the lubb(r ll1(tlwd Ii bas(d lH reported as nomiddotntoxic (9)
In phsiological experiments tll( alllount of nilable 1l1aietial is often vely low and lubbel ])(ll((ntats J)(low 1 PlI(Cnt- atl lIot uncomshymon Henep the 1(((1 fol Illllltl)tis lqually He(Ulntl JOt nil rnng(s of Lubber contents and rcql1iling tt 111inill1ll111 of plant lllai(lrialis emiddoti(lent It- j5 b(Iic(d that tIl( Illtmiddothods dtgt-(liiJld Oil pn(s middotl to 10 mept these specjficati(l1s In tHhlitlOll the IJl(JtClt111I(S dlS(Libcd t1wle aLC relashytively rflpid
Although these J1wthods welt ltlPlloped primneily fOI llse in rosea1eh on glHl~rule pJ~ysi()loy Ih(y hmiddot( widI ~ppli(nti()I~ riley han b(en uld til lOlltllH 1Jtul( llIlgtbpI alit l(SIIlS tlnalslgt HI an eqnal basi with the 1H0difi~lt1 SpeJlCl-Cnld(lIlllcthod in the gCIlPrul rubber labomtory Special Guayuil Rpsearclt Project since August 1043 They should alo he of ntllll in dptllIIIinin lllbbel lllldlcsins in guaYlll( bre(dillg mn(Nial aIHl iJl ollicl it ud its foJ wh iell plnnt lllatllial is lit II it((l
ROCEDUHES
PnEIAIIATION OF SAMPLES
The details of prepalation of tll( tissllc ~ulllplc are hpt (onslant tluouhollt any 1) rtiellla I I(s(allh Ploj((t Vhl11 portiolls of the same samplps are tnlwll foJ eh(mienl al1alJses h(sic1cs Il1blgtlI anc1lesins the plnnt parts alc dJi(ld ithollt PI(tlpatmlnt Yhlthpr Slpalflte mmples arc talnl1 for the otlwl analyses 01 tllP iolp pl1lpose i obtninshyi ng an estimate of the totrtllllbbel and Iesi ns tlw pIa nls Ol plnnt pnrts arp pa((d in hoiling ralpl fo f minlltps (paJJoiIN])l1 and uny lCfiyes slill adhering to tIl( SIPIlIS alc 1llTlowd hv ta pping on a table top
The plnnts 01 plant pUltS nlp sllbslqucntly coarsely ground in a Viley or otillI suitablp mill and drip to pc1(Cnt or iPssmoisture in a IllcChnnieal ltomNtion onn at (joj C l)(OIp thp final grinding A drying period of nt least 2-1 IlOu1s is IPqu iLN Ill( dried tissue is then grollnd in a ltnml11t1 mill (n llntil it pasls throllgh It 2- or 25shy111m SC]pe1 Th( mill is prodded with a ground win to Iemove stalic elpctricity fronl til slmpl BltWll1l snmplpsit is (]ennNl thoroughly by blowing with eompllsHd niL The ground samplps are tOl((l in ahtight contaimIs Viele-mouth
bottles Hh metnl 01 plastic SClPW tops are 1I0sI COlwcn ilnl for this purpose
8i11(( the J(lsnltsin mot physio]ogi(1I1 PXIlltlinPllfs nre Ixplessed 011 the basis of tllP d I wpight of hI otigi nil I Sit 1I1pJt (II)(d to (onsiant weight at 100 C it is ltifirable to (SPIPS thl finnl IlIbhCt awl 1(ins contents on tlw sn Illl basis A (OlIP( iOll fad Ol i- t h(J(fote d(I(Ishymi1Nl Oil the (inply glOlll1(l 1lotol1ghly mispel sample bY dtying snlnll rluplieate SllbSHlllphs t 1 to 2 gnl) 101 R houts at IO(Fin In ordinary
U rhp plncO( of Pl Iboiling- g-narllllt 1111111 fOI IPIJ1f1yn I of 1(1Y was dyploppd h (mplop of th IntfI(ul1titwlltai Rllhllpl ro CL r (lI(III ]Jxj1lillHntmiddot ~-24) ~PJlt 15 1928) lind nlo IlJlPlirc1 by otlWl flJIployp(s ill Intpl YlI1l~s rhis was nS(PItaiJ1(1(1 from til( fi)(~ oC Ill IntllOIltilllllal HnbbPJ (0 now fill 1110))shyclty of till U S DppuLtIncnt of Agrlcl1itULe
bull
bull
bull
bull
bull
bull
RAPID PHOlOMErRIC DETERlrINATION or RGBBER AND RESIN) 5
drying oyen hen the samples are yery snlall minimum umounts at tissue in wry small weighing bottles t35 CIll high and 22 em in diameter) are usee to (Ol1SNTe ti-ue The sumples pound01 analysis are then w(iglwd Ollt Oil tlil llalis of (onsl Ltlt dry weight at 1000 by using the factor fol 1l10isttllC COIlP(fion
lJAGE~TS FOH RtBBEH AlALYSIS
In a l111lllbpl of eases in tllis -(cti(Jll nnd the Olle on Heagents fotmiddot HesinLllltlvsi It(llllilttl-gltlde dlllllieal whielt were the best obtainshyabll during tIl Wlll])(gtlio(L fLtP indklttd These proed adequate but wllln b(itleL glatils HIe inailahle tIll) (HII he cl1(gt(ke(l to dcleLlnine lny adntntugts of lIbsl ituting p gllltlps rill nbbpl and rtsins soh-enls HIC kept ill glas--ioPPlllll bot Lt
Sollenl~-Methyljs()lJlItyl kl~t(JII(gt t(hnicalgrllll lIbOIl amp Cmbide Chemshylenls COlp is (nUlply latiII(tOIY fol 1I1ltuIHI 11IblJl1 lt is IPportell us appalshylutlr Ilontoxie UI) Although it has thp (IHIIl(fplJ it IWOIll ollor this is leSS IllOIlOUIl(ld than that of othlr IHIOIHs ((Ilsfnuls fol this lIud other rubbel -lIlrellts art given in tuble 1
lAlllE l-Propumiddotfirlr of Hfulr drubIeI olld I(~ills SOllCllts completely soIlvie in 9JpccI)Jt cUtawt
olu billt r (reshyHnilmiddot lation to weight mg ~yenI~NI~ I at (J0 C)point ~1hSolvent FOrl1uh (Ill llOlnl (IIlII(l
lUIIl ruhber 01middot Wut~r llg nlI in lusomiddot
wlter vent
Hubber sohcut c c Benzene l _ elf ~nl ILU olulole ~[NhYI iobutyl k CHltlH(JIC(J(H II 23V do
tonl LNbyllHlfllyl ketOlw (If c1I3IUIllUmiddotoCli lW r 4S U _ do 43 1 1 Diiohtllyl kNone ICH([JemiddotJjlWmiddotU(ll(I1 11 fln 010 06 45 Butyl nCltllt~ (I1roeJ(I1 12fi3 a7~ do fiS 12 ~Iethyl amyl atNnW (ljCO(j(lH1 (Jl(J1lIJ 1 IIi 3 131 lt10 13 1lS Ethylene ~IH-oI dimiddot CjlJO( HtI1O(fh _ 121 I 3J () 110 210 3
rtllyl Nlllr ~middothutyl (ther (ThO Ih 112 37 ~ tlo 03 19
Rcsins oh-cuIsACNone I _ clI C()( If I -~middotI lrNiuhll I()() 100 cetonylnclonp Cn (middoto(JJcHlt()(I WI I ~H tlu UKI llJO EthylD( glycol mollmiddot CHUCUCII0H 13[1 rl2 _10 1(10 100
oNhyl Nher (((lIoshyFohc)
Diethylene gly(ul 3u 7 1111 ~flo lOU 100 mOllohutyl Nlltr Ibmyl carbitol
I fncllulbullbull j lor rOllp3rison lnly
RIlJJIIJ1J( (illituliIlQ SOIIIUJII Oi-I)PtcPIlI n~() (c ll rellg(nt Ill Pont SP gr L~H) oluUolI ill JJ-ptrtPlI( p[buJo Ily ulullIe iR upd as a lUlJbel Illpd) tall r
lrue(it-c Colloid SrltlioJ for RIlJIII A middottipcImiddotPllt iulutillu of diglycol stellshyInte S Or glycu~ttlill a retllJld g)1I11 ur tlid)(middotul nlmt Hot llYailllbe (luring the war pellod) (bUIll tlellnj(IIImiddotIndt Ulycu Prot ItI (middotu- I i IIllHlt ill lIl0lj)homiddot lille (lecbniC(ll-glu(p EusnHllll I TIll slJ(k ur digl)( [ptrlltp ~ ued ill these expfliruellts on till bUSh of tim (htPlmiulltiom nt iJ C IYIIS illO(i 1-ereClt solub( in lll()rptvlilH) rlJe diglyt1 f(Ulute 8 i blOght U(II lllutiOIl by heating tll( oluuolt is made up 10 olmn I t a tandarll tllllf)(rtltUle (25middot
J Z30 King ltrcet Brooklyn N Y
6 TECHNICAL BULLETIN 920 r S DEP1 O~ AGIUCULTUHE
in the Writl Inborntory) al1l1 fiUerp1 A [j-I~re(gtl1t solution of this by volume is then made it thu k(tone Htptate or l(hPI or tht llIixtlll or tlH~p I~lll as tlw lullber foinnt
REAGENTS HHt RESINS ANALY3IS
Resins SUITIIN- Illixlule I)f a parIs ot lll(IJII~lIllII(JIll Hlld j pnrl~ (If fthSi IllI glnmiddoto] IlHlll1I1thII Nhpl (l(rtiIlHft(l 1CPIlPi i 0 as (middot110lt01middot1 I hr 01111111 botl t((hni(ul-glu(p CnlilOlI amp VHIhi((I h(lIli(d~ COImiddotpl is a gooe1 r(sin~ soiYPllt ~Ihis lllixtlll(I i~ 11(111( (0 ilS 1((loll~Il(ltlJlIPmiddotllll(Jllmiddotl amiddotmiddotj ill thl ((xt (011shys(allts I)f thf~( a 1111 011](1 rl~ill oYlll(s tn )inlI ill lalJl1
R(IIrmiddotpimiddot((middotJitlltill1 iWiIiOl- [i-(J(middotl((middotClImiddot 1I~O (e p (agln Oil Ponl f1 gl 114 J solul iOIl in HO by 0111111( is UStl m I Ill llills pll(ipita nt
Po(- i ( (ol()icl ~lJ11I1 iOIl Ol t(8Iyen-A O-IlPI(lnt olnl ion of (igl~((1 Rtrl ra i ( H or gly(o~t tlill I lIIath ill I (p( ollyln((1 OIl(middot(plJool( j or nlly ot Itpl rlsills solnnl 1I(tL TIJl diglYlol Hipn Ill ((i ~ is (lis~nlaquo hl 1 Itll tillg Illl lolLttioll i 11111111 liP 10 ulnnl( nla Ht1li1l1H11i tl1Il1ltIIItlllP Hilt 1IIllI((1 If thl -oll1liol1 liOllltl )(lOIllI loud) II((IIIP of II drop in ((IIII)(IH(III( 11( plPtipinll may hI hlollgltt IIHI ito ltulutioll hy It(lItill~
SIECIL EQrllIE[ Fon HlIlImn 1) HESS AALY5IS
11I0T())t1~TIG ISsTH L)IEITS
8((1111 tylllS ofi IlstllIIllllltS i Ill 1lid i Ilg tltl C01lIllflii e ] (((Ioni( plW((lJl tI OJOill(hI (oJ II1Illll dolllJltmiddot II lOll el(h1011111 t OJ SPII( IOplJOtollwtpJ Klett-Sull1llllrSOll o1olillltlI and EnIYIl pllOt(l(h-tJie cololimettt han b(PIl II~~(I TIll pilotoflttolOIlIltll apptUPlltly is llot suited for thl pUlposr iJltHlIP thl (hllJlIh~Jjstj of n( l-ollsplllliOlI IlHHStl1lll waS SLl(h that thplp WlIS velY ltLpitllhullge ill the rendingS oil standing of the liOlllt iOll a1tlI rubbl1 nnd Il-ill~ plltipital iOll fltP onitL of prefmiddot el(llce fl(lIll tilt ltalldpoillt of gllntls pllri-iol1 of llading~ is us follow
(1) CoWlIlan dOllhlt 1ll001O(ltlIII1lH I01 IWl1 Iuphllt 0111(1 PI mo(hl lOH 0 COPIlHlIl I1I1iY(lsnl SP(ctI1I11holl1nHt(1 Ilwdll 11-WaYlmiddot1I1g-1 It Rlllinl II t j() mLL is IlCIUlIllPlldl(i
(2l EnblI pholo(lptlli( (olulilll(Il1 wi It (Ining- 1II11 110(IIIUIlHl tie filt lr rOIllshyhillatioll jtl lIllL 12middot112UGc51- villstllt (ap i~ ~(t1 10 ((Jlr nl)lOIptioll IIt tllllP Wlllll 1(IIilll~ HI hlill 1lI1lt1t A nitmiddot fill holding 11 Itlllll nmgllifing IIHli til flllilitatt lIlaldll~ IIPPluxilllllll 11llIII11111letl1 I(adings tn 01 lila) hc IIJ1l1l1fll(lllld 10(lllIy
(H) KlpttmiddotHlIIllnllISOIi (OI(lIilll(tP-So ~Ililllhll Iiltpl (lInrllinnlion of IIPillllXimiddot nwlcls 50 IlIJL IIln( (Ilgth I atillhl( at 1Il(middot~(middotIlt Till ill(ItIIlWllt IWIfOIIlIS Hn tisrt((oil~ wit It th( IlIa iI II 1111 filt hpi ((11 iji 111111 njij IIIl for IlIlIlI(I II nIl1~si on 2-S(tllolll (Jl oltlll glltllh 11111 (prilll wit hlt l(lJlo((1 a 11(1 f(IJ~ currentmiddot plon ~1(jlh (101l IIII plnn[ with 111 t (1 ahlllp W(J IllJL 1l( lig Hl llIi 1illlit it USP(IlII(S$
ltOl the JlJ(~(Il( tlt( Ewlrn pllOtolIl(1 de (oIOlinwhl i 11(Olllllll1H1(d as (hI IlOt eOt1PlliPllt alld ndaptabltmiddot il1trlIl1lnt rOl rout illl lnbolttmiddot t OIY alltl ly~(-
OTIIEH I~QUIII~YI
A lhplllIoI11 i(ally (oll(lollltl tlil huth wilh a l(llIun1l1l (1(11 hllsk(t pllllimiddot liOlWl [0 hoW il)Il YOllllllPI( lIa~k~ ltig ] L llihglmiddota(]( tylil(il oil ~ K O i1((1
A tlt(IHW(1l tielHr (mil 1lIl1td 111 Ipl 1Jr t It IIIIIjdlt wir It lHolol iImiddotI(1 Illld IClllollhl ~(lllI IlIl~kl[ 1111 lt it jllll(( t h()1( i II Ill ltlOmiddotml Yonnrp[ riellllisl)I 11( in stnlltIItlllllg I Ill I lPlI (II 11 of IPII)(l1tlt Hila IIn)UIII of (xIII(Itl saJlpp~ Illkpl1 (01 Ilnlll~~i~
bull
bull
bull
7 RAPID PHOTOME1RIC DElERlHNATION OF RtBBER AND RESINS
bull
bull F1(rJm 1 ~ UIIIltan 11l~IIlInIPIII lo UIIlallt-lllllplalul( ~(II(Inl-[lllrpose hath 11fil1l liS au oil hath Xlltl ~IHinl 1(IIIOIullll win 1Jt[PI 101 holding ~[j-lJll Yo1U1l1plllt flask dUIlng- (xu iOIl ur luJhl t IHI IIill IlIi is uot stlludard ltfJuillll1ll1t nIHl 111lIt hi 1Ill((1 b1 (hI Hllal~-t
Ilm1ll E JIItnslIlPil iIIit (111([ (Iltaslll(11 [1111 In(J nlHI K()(lak electric tinwl Ilw Hutpl H~ 1l~Id ill I1PIIIllIillillg )1IIIdillg (illll n((uInl(l~ 111 111lt minute unll luhllpl HIII1 Isllll al( l11(ipIIIIlP(] 111111 till tOIlIlPI 101 tinling hlHtillg nml (11 tli fUli Ilg 11l1iulls
AWill~ 01 It Ball amp I(wpllluill fol Ull initial lWUSI glinllillg of gtllyul(l UsU( Hoss-llal(]pslr IIWllifillIlioll of Ihl lInlllllHI 11Iil I I plIlIilll] with Xo 1
(~middot1Il11l) nl1d XII (iIIlIII1 (lPIItS LYIPX i lUl(l lOOmiddotml oInllHUilt 1IlI~ llloidltl witlt grolllHlmiddotglns RlOPflllS spr-ial mIIIi 11lx ItitUllIti IIllIkll wllh UIlI illlIlp 1111111 1111(1 gillS
10(1 12 CIIl iclllg h~ 1Ii jlll ill Ilillllllitl wHit gtOllIHI UnllIIPti IlId 1 em In dillllllll fOll1~p illlllllldllg lIbhll slutlon [fig A IUHllJ) 11)( jllpiul heakcr I lIJIIlI1fIIIIIlII11 t101Il Ihl W-1l1I lldUiIl low-fllllli 1IllkI wilh s[lout laquo(olning (llas WIllk Xo 11111(1) Till ll (toul I flatlll1lt1 hr (Ill lgl1lu glllliliIIOl[ing Plo(Il1m Ill IillltllIllI 11111 of Ihl gIllgt ruti aIHI IIIP sUIfa(( lit til( lIat insitle hottnlll of IIII )11111 nl( gIlltlIHI toglll)I wilh Itll(I~ ill 01((1 II) s((Ule the most II tisflnlory SulfH1 rill lil Illl I iOll
P~I(X WIIlIIt glI III 111( ll111L ill thilkms 10 II~( a It tIHS(~ III ([hiding luhl)(I Sfllll[llp
A Iolk Imil fill lISI ill diiltlill~ luhI 1111[111 H(Hy(Inl~ 1~T(lX 10middot1111 gllhmlllI (Pili Iifugp t 111H Ill]lillld wll It (011(1 1101111
lind (ork tupp (0 tit I Ill 2 ()
bull Filt1 tilk (fig 2 IJI 101 1)( with Ihl glltllunlld tublS ill thi o[WIati()n of
llOUling lIIIlillpli lx(nll illf jIIlI )lhIIIl1IY(I lIask IYIIHIlt ([illlluin l(slmiddot Ill At hp II11IPI a )Iuss lOI wit h I tIaltllll(l (lIll lIlS lI1ullIfnlul((l ill the Illhllln(()I~- fol this l1SI bill ii In (lilli(ll1t 10 -1(111( II PIIpound((( tit Howlwei tlte anilnblp filtpl ti(klIt1 tlll 1)111)111-1 lind was Intll lIhs(i~llll(l The fritte(l glass disk SII(S 110 rUlli1 lUll Ill llIlI in tliH O)IlIUlhJll hut hollis hlllk the liqllid II nil lPidlH in till ((111( PHill
Cuullipl(1))ipp(ll for tlllII~flJItng klotlls nnd uthI IlIgnnk Illnnis SlIInl pighin) III I (h li (Ill high alHI (III ill ([111111(1
8 TECHNICAL BULLErIN 020 e S DEPT OF AGIUCUUlUlUJ
bull
IHHH middotmiddotmiddot~Ollll of the ~Jl((iHI ~lnsswlI( reshyquilpd 101 [lh)lI and I(sills tllal~sis (lllss rod wilh lInttPIH(] (ml Loll alld tlitulatioll lJlll((I II]) 101 liSP ill bull IIlnlln~ sto1 solutions of IlliJlPI (olII1i lwanshydlltr -AIIlI lYIX ((1I11ishyrllg tulJl wit Ii 011( poillt (0) nIHI flIIpI stie ( J) I fOlllSP ill P[)lIill~ utl (llIdiIli (X( lels witlt shyout di~tlllhill~ the inshysulilhll Ipsidlp
bull
Glns pound1111])(1 ) jlllll in ((iamptl for 1( ill tltlm~rprljlJg- pighpll fllJlplpS HIIl1
bull (lnrin(d IXIIat to -llil ohllnlllI f1aI~
i(p-mollllt gingt hntl will llntit OJ 11I(lal J(IP (n] fOI toling- gIollIH plallt samp(
Halmiddotk for hllldhlg ill-llll middotPIlIlilnp nlHs IIIH ~i-1I11 YOlIll1pllit flll (Jig- 31 Alltolllnti 10(1-1111 ~middotI(lX IlIllPUp of IhI fq)p llsltd fOl Iitis with intpl(middothallg(middot
nh1t H(JlIlHI joint 101 rl1phl lPfIPIIIlg (lj 1lIhhpl fllld 1(ill lll((jpiltlllls
bull
FllilHE Had Iqllind fool IIJI(lill I 11 (111111111laquo llllmiddot alHl (I) limJ VfIlIlllllJi( tlak~
bull TIll itl1jHlIlWI of n Illb tlpl of d(Hdill(~~ III [gtJ(Jtnllllllil lllll~
i dblmiddotwmiddotpt hy Y (J( I _ j J i) t Illt riflllmiddot t tth~ n n Ii 11 111 h111 I t1loOIlldy witl nap lllltlIHI 1111 1l1id bpll tlll- HII lill(ll with (jtt11lill olutioll Hlld ltll If fla k It It [lllijljtnlld 111bhll nl
11ill lIll til ~tlllld all 111th Ill lillI Illmiddotforl 111l In 1(11 it j~ luhmiddotjlIll] 10 1111 0111 ilH (111(11 11[ Jpli~ Ii tllp wall TIll
10 TECHNICAL BULLETIN 920 U S DEPT OF AGRICULlURE
25- and 100-m1 volumetric flasks arc rinsed two or thrce times with tap water and then with cleaning solution al1tl watel as is customtny In all cases the rinsed glassware is dried in an inv(ltell position at 100111 temperattlre 01 upright in a drying oven The flasks used IoJ extracshytion of rubber Iron1 kok-sagh)z (Talllrl(((IM1 kO-8aghyz Rodin) are finally rinsed wHh the solvent to be used and are nllmnd to lt1Inin and dry under a ventilated hood Cuwttes 01 absOlption test tubes nre handled and cleaned aH directed by the manufacturC)s of the llhotoshymetric instruments used
RUBBER (CAOUTCHOUC) CALIBRATION CURVES
GENERAL CONSIDEHATIONS
The lubbeL hyclroc~rbon stau(ild is pllpa 1((1 by extracting the rubber from guayule bssue ac(ordll1g to tilt SPCI1((-Caldw(llmethocl (5) 01 by the Holll1lH-HaasiH modification of this method (p 2) The air-dry extraeted ltlbber is dried furtlllr in It vacuum OYCl1 with 30 inches of yaCH1Il11 at 63 0 C for 4 hOlIlH Till rubhlI sbindanl is preshyserved h1 It clos(cl contaim1 sto1(d in It r(fligellltol BCfole th( samples nrc weighe(l out the unopened cOIlbdn(l with the rubber i~ brought again to room tllllpelutnre
Two stock solutions each in triplicate from separately extractml standard rubber satnples nre prepared-the first sct of (-111(( containshying 01 percent 01 1 mg of luhbC1 ])(1 lniHilit(l and the other 02 pershycent 012 mg of rubber pel miJlilit(l TIl( (I(~il(d w(ight of rubb(L contiiinec1 in It known VOlIl11e of th(~ solycntis withdrawn Irom Il
burette or pipetted and made up to 25 m1 the standard volume used throughout the procedu]e
The rubbcr samples (01 and 02 gn1) for the stock solutions are weiOhecl out to an aCClllal) of o~ mg on nn analyti(~al balance The rubber is best mnnipulated by mNlI1S of t1l( stJai~ht hlunt-edged top of It cork knife With a little prnctie( OIl( (an leltlily sepnrate t)w desired portions by pLeSSIl1C from aboye Further subdivision Is mndt on a stout PVllX at(h glnssnt lla~t 2 mill in thlkne~s By pressun f10111 above and sheuling aetlOl1 Ye1~ small pnrbcllH can be separntetl so that the requit((1 11l110unts (un 1)( w(igh((l Ollt accurately The rubber sample is then divided into sl11a11 piC(es on the special watch glass by meanH 01 II coll Imife
One mil1ilit(gtl of lt1i isobutyl ketone 13 js placed in It special 30-m1 trituration beaker (fig ~B) and the fine1y diyilt1ec1lubber sample (01 or 02 gll1) is udd(d and heated on a hot plate under n ventilated hood to Il tempelature jllst under th( boilin~ point of the olvent A special glass rod il used t () t rit II ate the sumple (fig 2 11)
When the rubl)(r hll d issohed so as to makl a hOll1og(J1lOUS geUike 111I1SS hot methyl isohutyl ketone or an oI the other luhb(L solvents recommended (t aIJI( 1) is add(d and niicd with the rubber soltItion
31 Diisoblltyl ketoul WIlS not aailab1p (Juring ValtimC l1Cthyl isolJutylletonC 1II1ly be substitnClt1 11111 it is not a~ Cf1kiCni In Illis olllntion If the IllttC1 is used It is b(SI to pl Ilw fimlr diillPll Iubhpl palll(s slan( oPIuight in Ih( solvCnt lind 10 (OPl til (onlalll1 to IllinilllizC elIpornt(111 of sohPIII bpfolp wa( Is nppliecl to completp nlutioll
bull
bull
bull
bull
bull
bull
RAPID PHOTOMElRIC DElERMINAlIOX OF RUBBER AND RESINS 11
The mixture is tllll1sterled to It 100-ml yolumetlic flask with sevtlul washings of hot solvent cooled to n s(uHluld telllpelatUle and madtmiddot up to volume with the saIne solwlli SlwtiaJ IHl(uutioll mllst be takell in transferring t)( lubbCl solutioll to till YolulIHtrie flask so thnt llO rubber is lost It is cOllytllielit to illSllt It j-ill(h funnel in the ne(k of th(~ voiumptic flask to pOll tll( lubb(ll solut ion ill OIl( OLWlHtion into the tube of tht IUlll1ll with Ihl aid of tIl( glllss Iod nlld 10 follow illlshyl1eilintely with S(gtllnl ~Ynshings of hot S() I(111 whkh lIl lilst pouled 1nto tIll btll PI 1I(ld dIIleUy OW) till 1unn1 aId IhpII t1I1uugh Ill( funnel
H time hi not all objllt it is uls() flasible 10 p1alt Ihp linely diided particles of Iubblt ill tl( flask toJ1tuining Ihl sohPIlI 11(1 allo it 10 stand until til( 1lIbbpI is dissolYld TIl( llIblJll ioluliol)s alp slolpd in Ihe tightly s(ojlP(1(d OIUllwt lit f1nks in a ((lol dark placl Thel they willltIIlUlIl (OlUilallt ill Idut 101 an indlfinit( JlPIiod
Two ellliblHliol1 (IlP~ flIP IIltl(l(-OIl( 101 o~ gill of tisHlIP (ollin illshyhw 0] to 10 PII((Il of rubb(I ((1lt)middot1 to U mg of IlIbb(Iill tt ~)-1Il1 yo1ullll) and th(middot otlHl for ()~ gil) of tisslIp (ollaining 10 10 ~l() peLshycent of lublJPl (O to 10 Illg of lulllJpI ill a ~)-))Jl YOIlII1IP)
(Hns HlJ 111 TO 1 II~IWEX( (II BIIII1EH
III oldl) to ll(llllP (ITOI (0 II Iltinil1lIl1l a lIitahl( lllillobllllltp is lIs((lo Jl((lpn (P IhI ~lt of stal1da Id solut iOlls 0 f a Ii ng (OJllllllllll ious ill til(gt (III)(r( Ol 10 1 gt(I((lIt of LubbI In (11( PI(sPIII WOlk th( 1111shypIoypd HlhlHIg mic)obm(ltp Il bullJ) whkh lIi(IlJalpl dlli(I~ 10 0001 1111 was Toulld sntisiadOlY F(OIll n lll-pltIllllt -talHlulIlllbwl solushytion in HSlIitnbh solnnl lt[lIiIlIUJl1iiat( aliqll()l~or n) Ol o~ n and ()t 1111 al(lllla~UIpd (Jilt ut n stalldUld ~Olllli(lll tlIlIJl(1atulp (~) C ill wlitllmiddots labolulol) I IlIIHIl-of II lllillOillIl(tlt illio ~l-lld yohulI(lie f1nks ploid(d it h gla -(OPIllIS gllollgh of 11ll lubhpl sol Pili i~ thllI addltl to (tl(lt flask to IlIak(1 l 1111 Ill1I IUI(middotc (0 t hl all)ollllt of lllbOPI solutioll ]ll(yiously nd(lpdbullflll DI ntl 01 JlImiddototlmiddottli lolloid solu tillil Iras h(PIl Hddld lIP (bhpl is JlI((i pi III tpd IIlld SP(middot(t )opl)()tolllshyd(gt( 01 (jIOlilllltp) IPallil) an IllHdp 1I((OIdillg to 11ll JlI()(pduJ( Oil shylitwd Oil pagp 1middot1 Th( 1(ldillg~ 101 palmiddotll (OI1((III)Hlioll alp 1I(Iaglt1 anel plotttd Hgaillsl t( ntilligllIlll of 11))1 hI n ~)-1ll1 (jIIlIlH 0) [gt(lClntagl of nlbblI (nltuln(pt 011 tw bnis of tl2-glll lilsul Slllllp1(gts and aliqilOt olulllt IH(IOI 101 (itl ]1I(J((dlll( out lilll(1 Oil pagl 1middot1 This PI()((lhll( i ((l(alld t win ill (a(1 (11( II slandald llIbbllsolushytion was PI(gtllllpd IIOIlI slpa latll XllH(1 ld 1 a utln)(l lllbblI 1 III pips TlwcOlllpl(tpdtlla alp pol(l (1) (loldilla pap(laslrowl1 ill figulp I
Tbl )llO(p(II I ill lllilking a (Uln rOl I to ~ jiI((lIt of JlIlJh(1 i~ simi1t1I to (hat rOl 1Ill l1IlP ImI1 to 1 JllI(PIII (x((pl ill a f(middot dptnils The quinlu]lli(Htl aliqllols a 1( sput(d Ht (lI 12 a j 0 (78 n alld 10 mg ])(gt1 ~i-1Il1 Yolunl III sNuIing thp 01 Illg pll 2)-Jll1 YUlll))lt til( (gtIO(ltlIII( outlillPcl ill IIIl PIp(tding pnltlgllIph is followpd In the rllngl 1 toj Illg )IN ~)-1I11 OtIIl1I Ilw (lsi 1(lt1 (oJ)(tlllltlliollS of lubbpI alP s(gt(ul(gt(l h IlIPHsuljng alhplOi- with Xnlional BIII(atl of Stnndlld~ tltllsf(I pip(Ws flOIl) tltl OI-PlIl(1l1 lII))ll sol III ion
12 TECHNICAL BULLETIN 920 U S DEP1 OIr AGRICULTUHE
RUBBER IN 25-ML VOLUME(MGl
100 1~__middotOT5___ITO___15__2~O=--_bull 2r5_---= bull 3rO__~-_40 bull99
98 shy(I) CI Z
~ 97 ItJ II
~ 96a f-IIJ
e95 o l
94
93
92 ~__~__~__~____L-__~__-L__~L-__~__-L__~
o 1 2 3 4 5 6 7 8 9 10 RUBBER (PERCENT) bull
FIGURE 4-Cnllbrntioll curve for rubber in 02 gill of gt1n~ule tissue containing 01 to 10 p(rcpnt 0 lllbhlI (nlnllillg~ (Ill 1111 J~pl~ll llhooplf(middotttmiddotlc colorimeter with 720middotmu filter und amiddotml uperture the 01 divisions required in actual pracmiddot tice for photometric IclHlings arc olllittltd)
Similarly hl the range 5 to JO mg pel 25-ml Yolume the desired conshycentrations of rnbber urc measured from the O2-pllmiddotcellt solution The complete data lire plotted on semilogtllmiddotithmic pttpel as shown in figure 5 A
STANDARDlZATJON AGAINSL G1IA111 ETlIIU 11 ETHO()
1he alternate ploee(lule of stt121l1ald izing th~ IneHell~ method ngninst the Spellcc-Cald well method (II) altholl~h flaSI hIe 18 not adVIsable because of the extra work J(quiled ancl the introduction of the expershyimental error of the benzene extraction method
HESINS CALlBllATION CUIlVES
The procedure for constructing cal])lation eUlves for resins ttIlulysis is similar to thtni outlinlltl for lubb(l lxcept that resins exndate of gunyule is lIsed as the resins stundard The resinolls exudate disshysolves very readily in the resins solvents listed in table 1 It may be prepared in two ways for use as a stnndard-the clean exudate as bull gathcrcd from the plants is dried for 6110mB nt 65deg C nt a 30-inch ltcuum or the oXllllate is dissolved ill acetone and filtered In drying
bull
bull
bull
RAPID PHOfOMElRIC DJllImlMINAlION OF RUB BEn AND HESINS 13
RUBBER IN 25-MLVOLUME(MG) 2 3 4 5 6 7 8 9 10
r~
eo en ()
90
f--70z Q ~ 60ltl LIJ a ~ a LIJ 40 E 0
0 50
~ 0 ~ I 30 0 ~
A 20 I I
o 25 50 75 100 125 150 175 200 225 250 RU88ER(PERCENT)
RESINS IN 25-MLVOLLIME (MG) 2 3 4 5 6 7 8 9 10
1--90
80
en () 70
I z Q 60ltl LIJ a
50 0
a ~ LIJ 40 E 0 0 ~ I 30 0
B ~I20 o 25 50 75 100 125 150 175 200 225 250
RESINS (PERCENT)
lJIGunE u-Cnlibrutioll cUve for (il) rubhcr in 02 gill of gllnn11c tisme conshytainingl to 2G perc(lt of 11IUU(Il I1na (1]) rpSillS in 02 gill of glI1~l1ll~ tissue (ontnining l to 20 nelecnt oC l(sin8 (U(ndings Oil 1111 E(lI~1I llhotollectlit colorlmeter with 720-mtL filtcr and O-ntJ aperture the lO divisions llquired In uctnul prllctlce for pitotoulPtlie PllllillgS tlre omitted)
in vncuo arelntivply HllHlll qUllntity of (xutlnte is plllcel] in a lalge dish since the mass rOHmS nt the beginning of the drying process Pracshytically ull of the ne(tone is evnpollltpd olf oyer a steam Ol WItter bath and the residue is dli((l pnlYllized in It mortnr and preserved by
14 lECHNLCAL BULLErrN H20 U S DEPl OF AGRICULTURE
drying as indicated for fresh exudate In all ClSeS the products are stored in airtight containers in a dark coul place
The usualllnge of resins from gunyule tissue is about 2 to S percent on a dry-weight basis For work with this plaut therefore on1~ one curve is needed A typiCallesins ealibrntion CUlTe is shown in figure 5B
PnocEDuuE J~OH RUBBER ANALYSIS
Duplicate lXiLllCtiOllS arc made for each tissue analyzed and duplishycate photometric readings are made for each cxtmctioll the final value therefore reportcdreprescnt- nn avcragc based on the four phoshytometric readings
Thoroughly mixed O2-gm samples of the finely ground tissue are weighcd for analysis on the basis of l11oistUlc-frec tissllc The samples arc weighed to an accuracy of 02 mg Oil an analytical balance The method of deriying factors for making eOllections for moisture in samples has been thtailed on page
The weighed samples arc trallsien(c1 to the 2-m1 volumetlic flasks with the aid of l-inch glass funnels and 20 m1 of methyl isobutyl ketone is added to each flask The contents in the Hasks are heated m a constant-temperature oil bath at 115 0 C for 30 minutes uncleI a yentilated hood rhe flasks are removed and any adhering oil on the outside is wiped off with Kleenex 01 H similal cellulose tissue the C011shytents of the flasks am cooled to a standard tempellltule (25 0 in the writers laboratory) in a constant-tempelutllre ater bath provided with a motor stirrer if available and made up to volume with the solvent After the contents are mixed the flasks are allowed to stand for a few minutes until most of the insoluble residue settlcs to the botshytom The extracts are then carefully poured into JO-m1 heavy-duty centrifuge ulJls so as to include as little as possible of the settled insolushyble residue The centrifuge tubes are stoppered with cork stoppers and the liquid is clalifiecl by centrifuging for 10 minutes at 2000 revoshylutions pCI minute The clarified lIquid is poured into 25-m1 volushyl1Ietric flasks plOicled with ground stoppers It i impoJtant to pour off the clalificd (dlart in lWIt a lUlllie that the ill8ol11ble cNi(hwis not Sti1((Z1tp A 1-in(h funllel is plncCd in the neck of the volumetric flask A filter stick (fig 2 D) is inserted in the centrifuge tube through he liquid so that tlH enlnlged palt of the gtiek seals off the insoluble residue and a small portion of the exmet in the cone point 1Vith the index finger the stem of the filtel stick is thell held against the side of the tube towllnl the analyst who holds the tube with the thulllb rmtl t11illt1 fingCl The txtlHct is thell poured off easily into the yohunetlic flask without distnrbing the insoluble residne The COllshytents of the Hasks are then ))ollght to the standard tel11pelatme in the constant-tempentl111e wnter hath
The reagent blank us(d wit h the spectropllOtoll1lter 01 (olorimeter ig prepared as follogtvs ) 1111 of methyl isobutyl ketone 01 other solvent used is pipetted into It 25-m1 yolumetric fiask and 01 ml of protective colloid solution for rubber is added the mixtule is made IIp to olume with acidified Oil-pelcent ethnnol and mixed again the rcquired vo]shylime of the mixture is poured into a cuy(tte or an absorption test tube
From each plir of tissue extractions to 5-1lll aliquots 01 the clarishyfied extlact at the stnndanl tempCraLule ale pipcUed into 2ii-m1 volushy
bull
bull
bull
bull
bull
bull
RAPID P1IOTOMElRIC DETERMINATION Ol~ RUBBEH AND RESINS 15
metric flasks and 01 m1 of protective colloid solution for rubber is added to each One additional5-mL aliquot from each pair of extracshytions is similarly prepared to serve as a key to the standing times for the final readings as indicated in table 2 These additional aliquots are first made up to volume with the precipitant acidified Do-percent ethanol mixed by carefully inverting the flask three or four times] and allowed to stand for 4-minute periods before the reading is made on the colorimeter Vith these preliminary rendings a~ a basis the standing times for final readings are taken from table 2 For example if the colorimeter reading in rubber analysis at 4 minutes is 655 then the standing time is 15 minutes
The two rell1Lining duplicate aliquots for eath extraction are then made up to volume with acidified D5-percent ethanol mixed by careshyfuIly inverting the flask three or four times nnd allowed to stand for the required number of minutes as established by the preliminary 4-minute trial readings (table 2) before the final colorimeter readings are made on the contents of the flasks
TADLE 2-St(llllliIlU time for variolls (OllccntratioIlS Of rubbcr or rcsins aftcl iJleaipitation bcforc colorimetric readings mc macle
[5middotml aliquots of rubber in methyl isobutyl ketone or of rcsill~ in ncetonylncetonemiddotcellosol e 3middoti both made up to a 25middotml volume with pr~cipitantj readings on lvolyn photoGlectric colorimeter with i20middotml (690to iiOmiddotD11) filter and Umiddotml aperture]
RUDDER I
Range of colorimeter Approxima(e S~nuling i Rnnge of colorimeter Approximn(e Standingtrial readings after 4middot range in conmiddot tJIIIG for trini r(adings nfter 4 range in con tifillnlOalcor minute stunding time tcnt In tiSSU(l Unnl I t I t (rending IIlIDU C stum Illg lOW _ tent III Issue reading
Percent Villlits II Perfe~lt Jfinul 955-999 bullbullbull bullbullbullbull 09-01 00 01-03S bullbull ~ _bullbullbullbull_ Jl-O9 10 743-954 bullbullbull ~ bullbullbullbull __ _ 43-10 30 1420-550 bull ~ ~ 137-94 5 6_3_9-_74_2__bullbull_ bullbull bullbullbullbullbullbullbull_-_---- 6__8-_4_4---___ bull ~ ~ bullbull ____ MQrcthan 13ibullbull_-~_ _ ____ 15_~elow t~ 2
RESINS -----------------------------~--------
957-999bullbullbullbull ~ 139-01 60 11419-amp11bullbullbull _bullbullbullbullbull ~~ 13~5-939 10729-956bullbullbullbullbull_ Ii 25-1 middotJO 30 ~gtl2-40(L bullbullbullbullbullbullbullbullbullbullbullbullbull _ 2025-1320 5 595-728~~~ bullbullbullbull 8 as-G 20 20 IBelow 292 bullbullbullbullbullbullbullbull- More thun542-591 _bull ~ bullbullbull_bullbull_bullbullbull 038-039 15 2025 3
I Precipitated with O5middotplrccnt HSO in 05middotpercent ethanol When the npproxilllull concentrntion of rubber or rcsins in solution is not known trinl colorimeter rend
ings atmiddotJ minutes s(nnding till nrc mndelS n guide to the required finnl standing time indicated in the last column III prncticc UII cxtrn nliquot is prcpnred for precipitation and thIs is discarded after the trial reading is mnde
3 lrccipitnicd with OmiddotpcrccntlhSO ill HO
PnOCEDunE I-On UESIliS ANALYSIS
The procedure fol resins unulysis is the same as that indicitted for lubber analysis eomiddot(I]lt that f he -olyent js acetonylacetone-cellosolve ~)-7 tht precipitant js O5-perctnt H~SOI in H 2 0 and 01 1111 of the protective colloid solution for nsins is added to each 25-m1 flask conshytaining the aljquot of the extract before the precipitant is added
PnOlmmlHlC INSlHu~mNTs UECoIUlENDED AND CALCl]IAlION
OF UESurlS
Photometric readings of percentage of light transmittance (T) ale made on the Coltnum double monochromator spectrophotometer at
16 lECHNICAL BULLElIN 920) U S DEPT OF AGHICULlUHE
750-111 wave length or renclings n1( mnde on a colorimeter pLoic1eri with the monochromatic filter eOIl)Il1l1tioJl for sllecting the npploxishymate wfLYe ]cngth at 750 1Il~ For routine deterlllinations the Evelyn photoelectric colorinwt(r ployided with aTW-lllJ filteL is IC(0l1111HIHtll
The liquid in hich the preeipitnted lubber uld rcins are susshypended is pOll(d very cHrdully down the ill~idl of th( clette o absorption tube to lLYoilllllC fOLll1ntioll of ail bllbblls Aft( LUbbet find resins preeipitation wlwn the EnLynpho(otkcllie (olo1imetll is used the readings are nmde nft(L thl standing tillll- hOWll in table~ It has been foulld (OIlllliellt to 11lPtipilatl tublwr 01 llsiIlS from the aliquo(s at ~-millute illtlLvals This allows stlilieipnt tillle to check the eOlolimet(r and to makc 111( lNHlings Vlwll a ehangp is IlltHk fLom onc rending 10 the l1lxt it is advisablp 10 llle the clIvctte 01 absorption tube nt lpast twkp with slllall p(Iltion- of the llllltiol to be leitd
After the colorimd(L lluding lta e becll Iltndp till IlIl II igllIlllS of lubbel or resins or thc lpL(el1hlges pnslnt in Ihe aliqllot are r(u1 from cal ibmti(Hl (urVlS (fig~ 4 and raquo or from plepn Led tables of eqllivallBts baecl ill each (liSP on (x[lerimPlltnl data The results are expressed as percentages of dry weight (S hours drying nt 100deg 0) of the original tissue The errol lltle to lCflyjng the insoluble residtH in tbe voltlllletLie pxtLHclioll flflsk wlwn the pxtrnetis being mnde up to YOlllmC is V(ly slight sinlte only (U gm of tissue is used FOLroutine allalyscs lhis ery slight eLlor mny be dislpgnltec1
EXPERIMENTAL RESULTS
The experilllCnlal reslllts Oil hi(lthp method- of tU)lPI and l(sins analysis a le based ttl( d icussld blicfly hlrehl
PHEPMINrlON OF SAlULES
No difliclllty was expPtitI1(ed in pltparing slmplls of llllrscly-glOrt guayule plants 1pss thnn ~ YPH1S old 101 rllbbpl alld IPSills analysis In the cnl of Odll filld-gl()n gllayull plants PIIOtS hopel mtty be introdmp(l by the custOlllalY Jlwrhod 01 pICpalillg Ihp sampl(s 101
HlutlYHis as is lwipfly i n( ita ttd ill th is s((tion Smh enOlS do llot nffCct the ])lCcisioll O[ t1H llwt hotls for LllbbtL n nd Il~in~ nnn I sis i nee till) are due solely to tIl( tbsup--ampling (llo(pdule in thi (a~e of oldeL field-grown plall TIll 1lllt1lOcl of salllplill7 fipld-gl()l1 plants JllOLC than ~ Y(HrS old thenfort Ieqlliles iurtlHl jnttigntioll
lgtAHnOILr~G FOR HEllOVAL OF UUVLgtS
Parboiling which (onisls in boiling gllltyule plants in water [OJ
8 to 1~ ~ninll(s ~s col1llllonl) uSNl a~ n llHans of Itlli rCnl()y~l prior to drymg nnd gllnllng It I~ tHI([())P ll(e~Sllr to ltItLeLnunc all possiblt~ eflct oi tlti PLOtPlllll( )ll (Il( final results Exp(liments have sh(nm that (helt i- fl Flight loss ill til tmiddotjght of lOO(S and 4(ll1S In I typi(ul lXpelillltll hlu1llHs of ~- ii) -1-ytII-old gllllll( pllllb were Italnd at randolll Olll ( of talns wa- paLllOil((1 and the le~es (1( haIHI-pi(kpd [lom till o( hpJ Ht Both pis (1( dlipd for 48 hOttlS at (i) C in a llI((lwlli(al (011((( ion Oyell Th( lpsult are SUI11111I11izNI itS follows
bull
bull
bull
bull
bull
bull
RAPID PHOTOMETRIC DETERMI~ATIO~ OF IfCBBER A~D HESI~S 17
Dry ucilht lust ill lariOilillf
Plaut (pcrcrllO 1 1 -I2 ___________________ _
213 _____bull _____ bull __ _______ ___ ____________ 12 2(
pound(111_ ______________ 1 R
4_______________ _______________ __ _____
A __ bull __ -_
The efred of parboiling on till final lllalp i SUllllllatmiddoti7(middotd ill figmc G Rubb(1 lecoYelY w(t about 1 percent higher for parigtoillltl plants and lEsills re(ovelY somewhat o-er 1 i)(lr(lllt 10Wlr The (Ii tference in lublH-l r((o-elY cannot be ae(01111tltlt1 fot by loss in dry weight _ due is to be found in a study of thE grinding lwhadol of a parboiled and an unpnrboilEcl shrub The grinding of the patboiled shlub in the hnml111 mill is much fadlitated and ns a rule for tissue with a rubber contCnt below 10 peteent llO aggregates of rubber deelop in the 1Il11ehinr during the (Jpelatioll Yitll the unpnrboilNl shrub some dillictdty may 1)( (lxppliellrl(l Sill(( sOllle of till sti(ky ltxlldutl Oil the plant may scI( u nlldei for the fmllHltioll of lublH1 ngglPgates Til is apparently explnins the npparlllt los in ruhbpl frol1l the llnpariJoiled hrllb as eompnlelt1 with thl palboilld (fig (i) TI1(loss in r(sins
II
RUBBER
10 f-
Ishyz LIJ 0 0 LIJ 0
9 --RUBBER -shy-------shy
-- RES INS -shy---shy-----_
IJ) 8 I--Z IJ)
LIJ 0
0 7 f- RES I NS -0 -shy0 LIJ III III J 6 f shy0
LEAVES REMOVED BY PAFltBOILING
5 f shy -shy - BY HAND PICKING
4 I I I 35 30 25 20
SCREENS (SIZE OF OPENINGS IN MM)
FIGlRE Ii EtIe(t IIf pnlticlp sizE Oil lEcorPQ- of rubber lind (iiil1s when lEgttiye wEre remond hr Pl1liloiling lind h~ hand pi(king ((Dlltrol) plllllt1lt groUlld in t hammer mill
6114038-46-3
18 TECHNICAL BULLETIN 920 U S DEPT OF AGRICULTURE
recowry from pUboil(d shrub may be due to the loss of the resinous exnc1ate during parboiling This exudate forms ns It SClim on top of tlw )iquol in the tank
On the basis of t1wse results the recommendation is made not to yaly the nwthoC of leaf lemoYal in any 011( lNi(lu(h project Then fltirly compalabh IcmLts should he obUiined
70 ~------------------------------------------~ LEAVES REMOVED
BY PAR80lLING ____ BY HAND PICKING
60
-I-Z 1amp1 0 50 a 1amp1 a
en 1amp1 gt1amp1
40en gt-CD Q 1amp1 Z
I shy 1amp1 30 a l shyx C)
1amp1 ~ J 20 I shy 0 I shy
10
O+--L__L-~__L-~~--~~~~~ o 10 20 40 60 80 100
NATIONAL BUREAU OF STANDARDS SIEVES (MESH)
FlGntE T-lJiMlil)utiun of l1Ultkh si~(s of gnll~II( tiSSU( JrIOllll(l in a Ball amp 1ew(1 mill to pass six dllIerNlt S(I(euroII 1(IlYes Iemoved from plants by palmiddot boiling 11(1 hand picking ((olltloll dpfo1iatld plants dried to 1I lUoistufl l0I1t~nt (If 01 to o) 1)(ICl1It ground tiSSlli IbalH1 1() minutes ill II ~i$hel
bull
bull
bull Kahn shuk(f
RAPID PROTOMETRIC DETER~UXATIOX OF RrBBER AXD RESIX-i 19
GHl~DIgtiG
bull Th~ entire pant 01 plant l)iHt a~(gt fl r(ll it pllllIIirU1ry lSillg fur J hours ntGi~ C prIOr tD t 1( plChmll1atmiddot rLlmhll III a II lItmiddot or n Ball amp Jewell mill ~n llltllysis of paldch lzP- nftl~l (oar-( IIindill shows that tlwy ar( about tIlt llllH fOl parbojlP(t awl IJllllluhoileu hrubs I fir 7)
The coalilly gloUllll ample i-- thPll Ildlll forI toUtmiddot at ni C afnr which it ha lllilobtllL(gt output of ~ llllut lII hmiddot- dptPlIIlilwltl by drying submlllpil- at 1110 fot hOtll- TIll 1 IIIIll i lltllt lmiddot0l111d hi a IluninHl mill TIll mo(lel uP(t in thi IIIk i 1I Hu IIIOilll mill as IllUllifill bv Hoss nnt Hartlet ( 1 -[1lt111- with n1ll1l1 pldushyrations ittI lilnbhell b rill HanlIolll V0ll11nHiol1 ElIillllmiddotrill (0 The size lutllihl11 iUlJnole So I ( 111m t ~ II t HUIII Xl) ~ I L~ 111m nnd So 4 lillllU1 11 ttllilhmiddotj 0 r tllP Imiddotlult~ p(lln-It willI t11(e Sll((IIiZtS with )arl)Oiltll awl uil)Jtllboiltd hrlll b lOwl1 in fif1l1fmiddot-- This hows t tnt 1middottttIl ~(I 1 llllll (Up jlllilnl IHlt that
r------~-------r--- ~ --r IHAMMER-MILL SCREEN
O~ NO1
NO2 ---shy U NO 3 ---II
I
bull lL
z
r ------ l 30 ~ gt III
i I Imiddot
i ~ I
I 1 I I
~ 20 I - 1 iii 1[ r 10 ~ ~ ~ I _ ~ I r A bullbull
o bull L-~__~__~~__- ~~ 20 40 60 80 100 40 60 80 100 200
NATIONAL BUREAU OF STANDARDS SIEVES (MESH 1
Yutln I i-tlillltiuli Hf pur id lZt f ~naY1l1 t middotnt r1 lI1 i ~ a hatlltlllI 1IIi11 to 1111 Lx IHtllllH middotIn Lt-anmiddot tIlllunl loy la1 litkh~ omrl t 1) tHul parbuih~ -t B ~ thmiddotfuliufptl ]~lahr thpt tu tt fit t 1 It+gtr-tt1 Jnui~tHn eunttlIt _~rnlitl tl~UP ltakmiddot~~ 10 UddU it~ 1 rtmiddot4~pt~middotK1~r ttakt-middot
bull So 1 gingt- 11 tt-liuin-Iy ltr~pl [lPlItl1tat of iilll 11animiddotImiddot- Eqltrimiddot tIlllll hnnmiddot llOWIl dutr fll llltldllllUU xtlutioH 11pound lnhbll lIl lP-ill frolll IolUlIl ~tlaYlllt tl-IlP by dlt IJwtmiddotlUlmiddot lItlilwd oil Ill 14 - 01
i-mllt 11111- -lwltld hi INd I li~ Ii I TIll lllhtIlttj of Itiu~ So 1 (lltll j thnt 11middotmiddot01middot lttwmiddot to amplil tltt Iollllli tilt art lpdnn ib
IntIIll ll~ i po--ihJI with tI lLllit Ilfltl[lll1t It honld l Plllplw izmiddotl rImt ilt tht h of -allllhmiddot with l lllblPl
~ontlnt of ill PPltllt til lIilll it i tlllt pll--ihl 10 11-middot t(1i Xli L
20 TECHNICAL BULLETIN 920 U S DEPT OF AGRICULlURE
Even with screcn No 2 difficult due to rnbbel tlcrltreCtlltiollS may be ob tl
encountered In thes~ caHeH it iH lWit to parboil the shlub fOL leaf lemonll and finally to dry to about 1 to ~ P(l((llt of tnoiibl1(l pound01 b(~t results jn ~rindillp in tlH hanmHl mill
It iH aclvlsable to provic1l thc hammer mill with a ground wire Hillel the presence of static electric (harges 011 tll(middot partkhH will ealls( Home of these to atlhelc to the inside of tllP (olltailWr OJ lila eallsc OI1l( of till pULticl( to form ngg1(llatls EIIolin lalllpling fl01l1 fhis SOI1I(I mlly be (onsi(h1llbl(middot
A1I10l1g the Holnllts with high boiling point that lIlay Ill IlHld in rubber anal)Hs I1IP Illllhyl n-alllyl ketolle methyl ioblltvl kptOIH diisobutyl (tOIH blltyl tHptate llethyl amyl 1Ittail (middotthyl(middotlllmiddot gly(ol diethvl (middotther and n-bntyl (middotthel (labl( 1) TIHse al( also I(sin 01shy
middotent but th( 1(~illS n1( held ill olution by the rll1)bpl pl(l(ipitant tthanol wll(1 lllbb(r is 1)J(lipitatNI (S(ll tabl(s alldmiddotl) On tIle basishyof the lxpHilllPlltH tll( btsf nil-round lolPlli -rol lS in 111( PIlHPllt method is lt1iisobutyl kPtonc wld(h was not IIltlllllfaltllllmiddotd ltIlling Vodd Yflr n A suitable Sl1lgtstit ute iH llHthyl jolllltyL htolt whi(h is l(porhd as llolltoxit UJ)
Clllos()IY(~ (ethykn( glYlol monopthyl (tIH1) blltyl earlgtitol (di(thyl(ll( gly(ol llIollobutyl (ti1(r)~ and acttonylacetOll( may be used as resins sohrCllts (table ] )
In the earlipr work with (sills analysis cpllosoly( alolle was selcmiddotet(d as a suitable solycnt Aitholllh (ell()~oh( alone is pxc(lllnt its rplllshytiwly gwatlL iscosity 1(I(b to bubbl( formation nft(I (SillS pr((ipi tatioll Thi- increased thp (xperimentnl (LTOI OIl of tltp othll I(sins solpnts tI((tollyla((tolH has the proppry of glpatly lNlulingshydH(OSity 11(11 altld(( 10 othr liquids This sohpnt tlHIeforl wa addp( to ((Uosoh( in slIflici(lJlt tlllIonnl to OPI(0111e the dinieulty On the basis (li~ex)le1inwllts ~ purts oi~ a(donyla((tOlll to I puts of (elloshysoh-f (bolll by olume) as Splldcmiddot(l Thp 01 hel Hoh(nl listed hutyl clLlbitol at l(llst the t((hnieal-g1lld( ploduct uSNl is appal(ntly not as good as eithe of t1w ot1(r two () a (ombinatioll of tlWSt
The SOlVllIts JOI liSt in tumlyzing artifkial lubbel$ hy tlw pr(senf method appllLently (lcllIHl on th(middot kind of llI))(I lIp-ityl (Jxidt is suitable Ol BUlla fi and hutyllthlI for butyllllbbl Tlwse reagents IlLe technical g1lld( Calboll amp CtllUil1t Ch(lllilai (OIP This Hllbjp(( hilS not bepn (XtpllHl(ly illwtigated by till WIit(I
PIIECIIIIJ-
All tlst fOl Ih( adlqlJalY or till IHllipitullb ll(Ollllllentillllll11Sl bl baset] on the plctisioll of tllP final I(snlts oiJtairwd with the methods The )redpittlllts s(1e((( n HpJ (xtcllsi( (xp(IimPlltatioll all HatiH~ factor (Hee fig Hi 111lt1 tabItmiddot (jH) Ext(IIin tllts llllTild Ollt hanmiddot shown that H Hatil-gtflltlOIy [gtIpeipitallt 101 1lIbblI is (li-p(IT(middotnt HzHO (c p reagent nil POll sp gl U-lmiddotJ) ill li-P(l(Put (tinmol by vohmlP liol (tllayul( Ipl-gtinl 1l)-P~ITImiddotllt H)~o ill Hl) by ollln( ii lL satishyfaeto7-y l)lp(ipitunt A solution of 1 palt of H~~o to 1 part of H~() (1-1) iI2So1 nnd abo yarious int(lIlIPdiat( proportions of tlllse suhshystanCPs giyp fait 1(511It8 but with till inlIptl(l ill [h(gt ratio of H~S01
~
bull
bull
bull
bull
bull
RAPID PHOTQlIEfRIC DETEMIlXATIOX OF HtBJER AXD RESIXS 21
to H 20 the )olutioll becollles somewhat vbcou5 and precautioll Il1Ult be taken to ttvoid bubble formation When it i5 poured into tilt Cllvettes
It should be lloted that both of these precipitants have an ftellleshymmiddottion It was found that when XHjOH was used in the rubber preshycipitant in pInt of H~~O~ the readings were -table l)Ut were not reshyproJutihk The lIl of XuOH in pInel of H 2SO j ran nHittble result as a llth H(HY(Pl WIWll til( li-P(l put lthatgtl in lublltl llnalysis or H~O illlP-ius anal)j wn-i uddint(1 thl eharalteliti(s of till liquid with pleeipitated ruhber or resiu in HI~P(ll-ioll n ren1 on the lpNmiddottroshyphotometel m tololinlPtprfollop(1 it lPgnlal lIlll II~ lxplaiHd on pHgP-I (Sl( figs 11 aIlIIl) Tid made it lloible to outain lEPJOshydlHibll tpnlt nntI (onplt1J1(Jttly till JpqnitPIl tlPgJPP of PJPcljoll
IIWIE(TI 1lt COl~101J)
Jtl thp ItJiPl middotxlwlillltnb hefoJ thtmiddot -1l]YIlIt allll pnmiddotdpitallb had lIptll ptoppJly adjutp(l it l fOllll tIuH till llP or a Ploltiw colloid -wll ltIi1)cJ [ttlJmiddotntl- imlIopl tll lmiddotpro]lIibility of the lPlllt JmUkllly ()Ilt 111 U lput lUlU illlihumiddot tOJllPOlUtl tpHd liglyeol teltlut( - llpanlItly IllmiddotlfP(] to lit til I1m t IHflll lImnnmiddott nftlr tlH filial prOIptlllll WtlP dlvPllill1 tlll 11lIlpfit (If thtmiddot [llltlltin lollohl wa Hot 0 natlv I1l(lhmiddotd III rlumiddot Ia- of tmiddot ill tllmiddottJmillaritlu it b [1 hmiddotjlmiddot til IIpoundgt Ir llH1 It liltr ill-llImiddottiT Ina lll ptlPII by it U( in ruhhfl mmly j 11If dtmiddottail fOJ tltt lllllmtlllll If thl plot pet in nlloid ~llntill tltlmiddotlImiddotmiddotlttlatiflll lIOlllllllhtiPI1 are iPllllll page
liTFHFEHliG COIOf
(hi II tht lllail 11111111111 that had til ill -111111 II urklll) om tlH method fot lublJtt tlIlO1 rpir- nlalv~i in plaut llllpll- wa ttl (lilll~ inare tIte (gt1[01 till to tIll ptP-PlHt f xi [aIWIIII- 111 TIlt amount of (olor varip from lUllIt tn -amp ]pplwHlI nlt rhmiddot lt IIf thE Hl(ltllial tllP part of till plllIt -lI11lhmiddot(l tilt hi-tlllY f tlll plaut mtteshyrial ~ub-lltInent to Itlllmiddotnmiddot-rill lliI 1011middotly OrllPI Inlw
In ruhlwr lrtl-i I Iii 1101 au Itmiddot 1Iplll11l by 111[ I--r ratmiddottilt thE -lllll]t with uptoIw or 1middotmiddotlIll-ol - wIdell [llllol- rlll loillriu nutttel autI thtmiddot lpill- Thi- howmiddotvt n(tnll- til lXtla -11gt1 ilt prlJ~edun) In lP-ill ltluay-i nllHufldy tlW[t j 11 1 1IO(PIlln fill the 11shylImya of hlulophyll Hwl rIlI-r middotIOII IHlttlmiddotJ dlH lUtl~ In plltIH withoUt alo aiftIriL till nmiddot ulttrll
111 pllIbIll1l Wi tilmiddotr hId h It-ImiddottHI tht Pltlpll 1 hlitlt lilt tlw tulllWlli tollImiddot uIwltllIIntut -lltUIhorlllllltll 1111 tIll tlettlllliIttwr IIf t 111 lWlrl-Uamiddot of bdt tl11blLlittUhmiddot r [1 tItmiddot preshyj
lipitatifll 1lJ llllllWI atbull 1iI- in III -1nrmiddottIi fHlttalldh nlrillU~ amount rf middotlorilig lIUlttll Iii lhll of ih lltmiddottllllhottohttt~l l~ol()r infrtl Hm II upd 1 rwmiddot tld~middottilmiddottll PlllItlhi~ f it j proYitiltl with tIll lilP--UlY tU(jlIdlllIlml tIltmiddotmiddot lllklllUIlI
EIECTIol OF 1 [EGTH~
-Ptfmiddott ral tracilull ru~lI gtIll fr 1 nllb t ~xtltd 1 lIlt-th vI iobmy1 ketommiddot lWtl rill [ Ixt lttltt ll UttollylaIiIitt1l11I1t~ ~-I itoiu YtHil)u~ typp of ~IHaylllt f i lItmiddot art hraquoil ill fio1ll1 ~l Th~ lp-nlt fill I11oohl uio[1t ttl willlr til tltN- fur rht IUiXtIUt iwliutll
100
22 TECHNICAL BULLErIN 920 U S DEP1
90 bull eo
I shyz 70LLI 0 a LLI a 60
LLI 0 50 z
a ENTIRE 2-MONTH-OLD PLANTS~ 40 b ROOTS AND BRANCHES OF ~ 3-TO 4-YEAR-OLD PLANTSen z WITH LEAVES REMOVED ex 30 a C CURRENT-SEASON GROWTH OF l- )-TO 4-YEAR-OLD PLANTS
20 WITH LEAVES REMOVED
d LEAVES FROM 3-TO 4-VEAR-OLD PLANTS
10 A
0
a Cd 100
b bull
10
80
I-Z 70LLI 0 a LLI 60a
LLI 0 50 z ex I shy 40 ~ en z ltI 30 a I shy
20
10 B
o~__~__~__~~--~--~--~--~----~--~--~ bull350 400 450 500 550 600 650 700 750 BOO 850
WAVE LENGTH lM~)
FJGcm O-Sll((middotlllll tramaniW1IHl (mrpS f(JI (xlmll 11011 n J1ll of jlta)nle tissur ill n 2--m1 Y011111P of (A) Illrthyl ji1I1J1ltsl krtonp 1111(1 (ll) nt(middottQnyla(umiddot tClIc-C(l1osuln a-i
bull
bull
bull
RAPID PHOTOlIElRIC DETEH-UXATroX OF ntBHEIl AXD HEstxs 23
ThE dula Pl(S(l1t(lltl indi(ntp Ihut 101 Illp ulimls llHthyl liohutyl htOlIl (lxtrHts (lI(I r(dolls of Il1Hxi11111III nigtol]gttioll wiH1I all (is-lIb 11 cOllsic1(]((l n1( blhn(11 wn ( ItIl( Its lIO to () I1It~ nlid Ii to Iii mJL
WhllNIS tlw I(gions of 1middottnL(s( light 1lnlllittamp al(l lgtPlW(PIl wan Ipllgtltsnr) to Ii nllt jW) 1I1JL nlld alio Silllill1l 111l1b (n SI(lIlId 101 nc(ton ]altmiddot(fmiddotollp-(llloolp ~ pxt Ill of 11a 1111 t illl TIl( (1101 du( to lolo ill tlw litlltitl a 1Il1 lullll(I tH lPill- hanmiddot bpllI PI(_ ipitated ma he 1((I1((d to fltI ynbhing poillt II ph( illg OJ illshylmiddotJall(( WIWp balld nhm ()) IIIJ1bullbull[1I111 lxjlPIitllll1b Illln -h()1 that Ih( lIIot uilahl( WHYI lHlIJ fOI 1-1 ill 1l11J1l(I HIH11Pill- illllllrsi i-in till IlPighl)()lllll()(l of ~llIl1lt bull
bull UIlIilHlIy of n typhn] lXPllillllllt to )10 l1iP(tiP ((JIlllo( of (ItOIS dul to lOIOl in 1llblnI Hnd Iill xtnumiddott 11(11 IIIIolp t jUl i p1llelll((l ill tub]lL Till llhlllt- 1tpIO]II Hnd ((llll~()h whit-h UI(I ](]Hllilltl n 1I01lllIhb1 01(111 lxt 11111 IIll 1llll)1 nmtp[in I and )(middotills Tid IIlnkl it poiblp nftlI tlIp uplll1tillll or tlll o1PIl( (0 [niH lip 1Iidl1p~ of lI111 11111(( ill lit ll11l1)[1 (llnlIb nlld Ihll
Sl(ll n ol1lliOI with tllP olnl IJllt illiollt HIl Iltlllll llllI (Ill ltllthpl prpipitnnt j Ihll1 nddld OUI ha a lIilPt lP( of till lIiciPlw of WH( lllIgth 7) lUI- ill llilllillatiu (nnl till tll Ixtll1I101l ()lll~
Tuu tmiddot-Elilll IJl flrldillY 11-1111 lrlllI IjfJI til islII 1 1(1 ([rllt IIIIIJIlIr JiIlIt~ if 1Il( Ihll 111111 k til I III Ilrln I 1Intd tf 11111 JiSf fill I I II I tIII Ilf Iilltl 1f1JlIIillII1f I Till 1[ 1 IId 1 (I (middotIt 11111 (I1I1iI1 1lf1IWtlfJlIIllfflr p middottrllhIJ11 II J III 7IImiddotIa 111 111 lilt jJIp 111 wilTII
t~t tnVIli~ ~nn r kn t~ i tmiddot ~~l Jr 1middotmt ltlTt
HmiddotOtt ~I~ lin t I ~ 1 t~~l ~qrmiddotthtmiddotrtwb
Hult-middottltlru t T Hw ullut rHtt~ r II I ~ PH~lllt
A~tmiddottHHjmiddott~rjd rl ~gtllh 1 tn~th~ ~ ~ middotI lt~ b w bull hmiddotth~ 1i~lIhun 1 Ii tnl Illd1 -11lt1(11i lullI lUI tJl ll~ t1~11n( I Ihan1li flfttIJir Ult I Uuhtltt ahuul l(hmiddottHmiddot~t trv r fti HIt lftbyl tlonhUt)1 k_hIl( 2 m~ fmiddotf tuhlHmiddotr In mlth~ llmiddotlf- 1 t r
t r_~ t j
Arhlitlltd ~llIIDHl NcWitn1 ( Ar-(lt()nc~middotttrrtrt ritJJI~ -Iu nllJtl4-middotr
ACtmiddottflnp fmiddotxtrn( ~ T-P511ftf tn mtmiddotth~ 1 ~difmiddotut~ kdn 2 nltt ulruhhtr in Un-tIl lltbu )J~IYt
rUth(Hl~hltlft HhubU
Illlh(I(t tttUtUt hUbtl til J ~jlitl(J Hilllll trtIIImiddotjtl1ll
(UShl I ~tlO wHllolH rulh r (middot1111$0]( J~rru t t )lthyl 15bullbull1middot1101 klll1l
Ili( UHUicbcul ~((i1rUtl ~ulu1iin 1middot lIUIll Ilti lrllltlllt I Ruhhr llt1thuI r1 -1 Irld
ltlt1111Sh 2 nuz f)rruhl~rm nlith~l tu- h f nt nil~middothgt(H] tlrlftmiddot 9lUtirtl middot1 1
rlcltfl( H(l dnllltml it
(IISllhH~rI( Iultruhtr CII05 1v ltTlft I 2 UI~r ublwr In llldh I hlt~1 11) lgtjdvr(llsl~9rlltmiddot middotlmin ~ I~ gt AIHItilltl no IrttipHallr iI
~ Bbnk 10ol m(thyl i~tmiddotut~i kdHn H 1 m1 j~~ l1rH-t lt~tlfltmiddotn sf n it ll HltlMjftr~nol O2~mlJ ~U~1o-ulp ti~tW -xtra~middotl(lt1 ltt 411 ml bull ie f Ct- kft rt t~ tirattJ middott ill r u l1kn ttJt
in metltl isobutyl kNqnf nn~i mljp ur tmiddotmiddot ~oml ~urr tttl i t w ltJj1JH kt 4t 3 nlank 1 mL((l1t~rthmiddot(middot mI mttr~ ~but a kmiddot tmiddotc d 11 ~ gtli~b~ hifIAft- fl~ lL lnti 149
ml8(dlfilll BO bull 02 gm guayule U$Stl(middot xUlClt-l tf(h tft wI n nmiddotmiddotmiddotlgt 1 lznt on tmiddot ~Jt r~1 ~~u~~ H~ iI~ thT
24 l$CHNlQAL BULLETlN l20l S DJltJPT OF AGHl(CLlOHJltJ
In table a is pl(sentc(l such c1il((t edlt1tIHC showing that thc (0101 Ixtrnetccl from guaYIIle tisslIe wit h II(P(OIl( n nd (pl1oso[yc is cll(div(ly sCIe(nec1 out by the s(lp(tion or wnw length )0 miL Oil t1w SI)((IOshyphotonwtpl This tnb]p all-HI ihos thai thl Juhlwl altl(l((1 (nn IJl quall shytitntivcly 1(I(()(Ipltl in tIlt PI(ilIH( or Ih (o]OIplnwPIials and Illsins and tlmt Iuhb(l WtlS nppnlllltly 1I0t (xtltI(((1 110111 11l glll1I1l lisslIt b~ tlHSP SOhlllts Thls( ((suIts ginmiddot (OliIHillg (idJt(( that t Iw IISI of waYl llngth i)ll 1Il) OIl till SppdTophot OIllltPI ii t hl 1101(1 p(oshy(ellule in photolllliTie IlIlalysis of luhhlI OJ l(sin-
SELEGTIO- OF )IOiOCUHO)IAIIC ItIIm ((1111110
On th( basis of th( IPHIlb shoWIl in tabl(l 1 al hlllpls (1( IIln(lp to SPCtl lC the PIO]Wl 11101lO(lIOl1ln til Ii ltlJ ((lIllIJi nIl ions 10 llIiOlS (oIOlimet(Is 111(gt 7W-Ill~ filtpl flllnhwd 101 til( I1~lI1l photoshyplpct1i( (o]oriJl1ltll fol which Ill( (hlll(IlIiitit~ oj t hl Ilda he light ilUIlBlIIhiSioll (t) elll nn -hO11 ill fig1lle 10 iws satlsfa(lolY IPshysultl 111( iiO-mL HitlI olllhintioll 101 whkh ttp (middotIatinmiddot light tlnnsmission (ullmiddotis a 1-0 showlI ill figllll (I is -nthdnlto1 hut this is not stnlHlnld NtllipmPlli
Up to fhl PlPHllt lIS(middotflll pound11((1 (ulllbinntions jn lltl iOO-I11L Iunge hayc nol bllll SlClIlld 101 lhp Klpt 1-1I1l1I11PISOIl (olOlinwtll bu fnltlwl nttCl1lpti 1( )(illg IlIHd
TJIpound OF ST~lmW AFTEH HIIJ1EII Oil HHSIS rlll~CIIITTI(J
~ considl1ltiol1 of ttp lillll of Inlllling af((1 plpeipital ion of 111gt)(1
01 l(sinSTlOIll ollltionis impoltant J(jl~ thC1HI(Plltngp of light IInIlSshy
11 rshy10 f shy
09 f shy ~750 Mil- DOMINANTI
~ 08 cshy I WAVE LENGTH z
I III III i O7 - I III
~06 - 05 shyw
a
Igti= 04 - 720 Mp DOMINANT ct WAVE LENGTH- ~ 03shy
02 f shy
01 t shy 1)O~~~gt~- J 600 700 800 900
WAVE LENGTH (Mp
bull
bull
bullFIGlRt IO- COJllPIUlItiw ~IW(middottltll tlnIlRlllii-lion (II (IllP( 101 1i11(1 olllhinulloll
with dominllnl Il(lllllgths at 720 and 7iO lUi
bull
bull
bull
HAPlD PHQTQlfE1IUC JjETER~lINATION OF Rnmrm AND HEtiINi 25
mitted (spertrophotoll1eleL lCuding-) Ol light (1 (tClcrl (phOlOshyJluol01l1et(L lcndillg~) i~ StlhjNl to (hangl
]fjt~l1le 11 and l~ show that ill til( (asc ot tJaugtIllitteltllight llJHC th~ (x[llliHlllIlnl (oIHlitiOllS tllpl j lilst n dtlln-e ill Pll~(lltngl or UllllslllittnlH( follrnY(l by It ptJiml of lClntin stability with only sliuht (1111 tHn- a f(Pl a lIt1ll1btJ of minutes The light t UIllllitblllll t l(1 ill(Iln~(s This lIIay IJP llllllJltlli7P(ll1 ffl II ow 1Ilt )( f(( darI oliIII tIIlIlNlIlitt(IIIlfJIIlh (iditilIiid Ilil1 pllIipintnl )uoshyIn Of ( 8inx in (~f1( I~iUII i~ Ild stahl I 11 itlll If 1inl nh prlshyilli(ioll of 11l1d(1 II IJIX f) jllIli II (fJJltfiIIlilty slllMI IIriot 1) IIIPldUnl1i tll(I1I rllltltilJl oj tJi~ Jlt jiot IUN ilUf Jxl1 will tIt( tOWI IItlllilil I 1llIlllblJIol I ill I~11l11111 d ill till ifjuids JjOI scnttplltl light 011 till phololltHJIOIl1lttl till dilPCt ion 01 elangl b tlw IPrfIi (If that illrli(atPll rOl tlulll1Jittp(lliuht It Itlll b( llluliJr I-(Pll that if l(middotndlnJ- IIIP mad n itl I t lIP ~()ll1d()lb lpalll this pllioJ of nmiddotlatirp tuigtility tllP llLot tIOllt thi Olll(P (nil bl IPdUCld to tIl lltini III 11 Ill TIll l~adiltg (illH~ bbll Oil tlHl datn rUl lublwls and llsinlt Illl ginll ill tnhh
50 r----------------------------------------------- f shyZ
~ 40 ~----~W~A~V~E~LE~N~G~T~H~7~5~0~M~P~~~~ ~ --------------------=-=-= ~ 30 f- WAVE LENGTH 540 M~ _z _____ ___ -=- __ _ ~ ------shyt ~_=---=-=--I GUAYULEIII 20 -Z HEVEA ltt II KOK-SAGHYZ f shy
4 6 8 10 12 14 (6 18 20 22 24 26 28 30 STANDING TIME (MINUTES)
FIlirtn 11 Emmiddot of wav hll~rh Il li~ltr tlall~lIIit1alHl aftI IUIlItHt -Imlli lug 111m for guaynh llmiddotn 011111 middotiolIlJh~z 1111111 llijlitul1 flolll 1lHlh~ll1Jllryl k11II11l ~(lilltlll h~ lwitlitll 111Inu1 111l~1It1 2)1111 o1U11111 (Helillins on (illllun tlunhll IlIIJlllw]ntllW111 lutl(I[lholtllllltlt with ijUjt Wlnl IHI Ilf1 I
11 EFFEGT OF Hbli 1 -()JXT10~
Tilt lnblwl ~()h(llh pxtnl( till IPillgt ubo It 1m nllu1- bellt -~atea thut ~lll 11-111- tUP olnbhmiddot ill middottIIlIlOl ~1It tlWIIJI( my U)t PIl (tlIHatcl WIth tl1l lullh(t I tahle lJ 1hln 1- -1111 tIll (llllstlOll of nny p()~iblt tITptt of XtIIl11 diflp]lws ill ((JlllPllttUliollS of 1l-in lil lolutioll alollJ with till 1lIltbpl TIU data ill wbh +ho on tIl( hn~is of (olorilllPill ladillU thaI tll( IIUOIl1t of lnbbll Plllipirntld 110111 Ilwthyl olnlld kptOlll olntioll IJ 1li-jHlllnt 1l)04 in 1-llltlIllt ethallol)- not amlll hy thl llllNlI(l of llvin aU1ouut of llins inolution bull
-----
26 rECHNICAL BULLEfiN 920 U S DEPl OF AGRICULlUHE
100
90
80(I) C)
z Ci 70 UI a 0 60 a ~ UI ~ 500 ~ 0 I Il 40
30
A 20
0
100
90
(I) 80 C)
z Ci 70 UI a 0
60a ~ UI E 0 50 ~ 0 I Il
4-0
30
B 20
0
--
--shy ---shy---
2 4 6 6 10 12 14 16
---shy= ~ ~ shy
-
2
025 05
10
15
20
25 -30
35 40
SO
-60
=70 80
16 20 2224 26 26 30
OS
- 10
IS
20
2S
30
35 40
-50
-60 -70 -80
bull MGPE 25-ML
VOLUME
bull
MGPER 25-ML VOLUME
Florm 12-EtTld (If till1l or Slllldill~ 011 light transmittallce (01 (A) gUllyulc lnUIl(I plccipitllitd frOIll llltt h~l isobutyl Ielollt solution Ily neidilic(l ethanul bull null (B) gUllyule ll~illii pre(ipitated flom aeltoll~lllcetOlll-Cl])osolY( 3-7 solushy11011 by H(illilip(i l1U (HPlldillg~ nt -lIlillult Ifllpluls 011 Evelyn photoelectric colorimellr with jU-lllp tlllll alit U-1I11 npN(lle spp also table 2)
bull
bull
RAPID PI-IOlOMEllUC DElEnMINAlION OF RUBBER AND RESINS 27
TADIbullbull ] 4-ReZation of amiddotmount of middottbber pleeipitate(Z Oln metltlIL isobutyl ketone 80lutions by OS-pereent H 2SO in 95-pere(lIIt ethanol to umollnt of resin8 udde(l U8 indivute(Z by colorimetrio readinU8
(Rubber ami resins cnlculntcd on bnsis of amounts in 5middotml ullquuts of extract from 02 gm of tissue in a 2fllll olumo( bull
Hubucl r~cocrell whcll rcsins nddcd as IndIcated Htbbor al1dcd (pllcollt) ---shy
__________bull_________ ~_12rpcrc~15011crccllt 7511crccnt IOOpcrcent
PerCtllt ercellt Percellt Percellt Percent o o o o o) 50 250 263 252 25000 500 500 500 500 700 750 750 751 749
1200 1250 1250 1250 1250
EXTRACTION TEMPEHATURE AND TIME
Typical experiments to detllmine the time required to secure maxishymum extmction of rubber und ltsills at 115deg U Ilre sUlIlmarized in figule 13 the solvents used-methyl isobutyl ketone for rubber anrl Ilcetonylacetone-cellosolve 3-7 for resins extraction-are very eflicicnt since under the conditions indicttted maximum values were secured after 30 minutes of ext1llction The most eflicient liquid for the bath (lig 1) used in extrtlcting rubber or resins is ~ high-grade cylinder oil (S A E ~O) The sand bath and such liquids as glycerol have proved unsatisfactory
RUBBER AND RESINS STANDARDS
According to the National BULeau of Standards 1-_ lhclc Is no gellcrnlly recoglllz(d standard lIIutcrlul [ior II rubber standard] The rubber hydroCllrbon ill llifferent samples of conmlcrciul smoked sheet or pale crepe from heclI pluntlltions nries from l~ 10 04 llercent of the totul nutletmiddot the most 11Ioruble conditions Of preparation
McPherson () has described a procedure for the pLeparation of pure heve~ (Hevea brasiliensis (H B K) MueH Arg) rubber from crude rubber or latex In the absence howevcr of ~ generally recogshyn12ed stalldard for rubber hydlQcllrbon [caoutchouc (CnHUs) xJ the standard adopted was that of the relnthely pure product secured from gunyule tissue txtractiotl nccording to the Spence-CaldweU method (5) or the motlified PIOCCdUlU of Hohnes lind Haasis (p 2) The details for constructing the calibration CULes are given on page 10 Standard rubber samples apparenl-]y can be stored for a long timc under the conditions des(libed on page 10 The duplicate colorimetric lendings for glULyule rubber newly extracted by the modified SpenceshyCaldwell method were ()J2 ench as compared with US) each for the sample extracted by the same method but stored 1 years In each case colorimeter rcadinllS were made on mixtures containing 2 mg of rubber in It 25-1111 Yolume
The selection of tt suitable standurd for guayule resins presents some dilliculties Tll(~ acetone extract of gUllyult estimated on (l gravishymetric busis~ for instance proved to be variable depending on the type of tissue sampled or season of sumpling because such fractions as
COllllllunlcntion dul(lt1 Octohtr 22 11H3
28 QECHNICAL BULLEQIN 920 U S DEPT OF AGRICTTIIlURE
16~==========================115 shy
14 bulli= 13 z ~ 12
ffi II Q
10 c w 9a w
8gto () 7w a
6a w
5en III ) 4 a
3
2
A 00 5 10 20 30 60 90
14~------------------------------------------- bull13
i= 12 z w II ()
a 10 w Q
9 c w 8 a w 7gt o () 6 w a 5 If)
z 4 If)
w 3 a
2
o+B~~__~__~____________~__________~ 5 10 20 30 60 90
HEATING TIME (111 NUTES)
lllGUltE 13-lDffect of time o( lICntillg O2-gm samples of gunynle tissue with solYlIt nt llfio C on lo(OVl)ry of lllhlJer alld 1Isim Lt HlIhblL extracted with methyl isohntyllwtone B resins Cxtll1cted with aCftonyla(etonc-cellosolve 3-7 bull
chlorophyll are weighed along with the resins in the acetone extruct but are not estimated by the present photometric method (fig 0) 1he use of a diffeJent stanclttrd waS therefore indicated
bull
bull
bull
RAPID PHOTOMETRIC DETERMINATION OF HUBBIm AND HESINS 29
The resins standard selected is based on n relatively pure source of resins the rcsinous exudnte 011 the stems of guuyule plants IJldimishynary expeliments with the resi nouS cxuclate from diffcrellt gllayu Ie strains of various ages indicatc nHlt there is little YaLiation in this subshystance on the basis of Colorimct(r readings 011 2-mg aliqllots of 01shypercent solution in It 2i-ml volume (tabl( li) Expelilll(lnts have shown that the air-dried (xuclate contains 3RtOH p(Ic(nt of -volatile matter This material is l(latiyt~ly stablp ill (OlllpoBition and is npshypurpntly on ly slight ly hygroBcopic as shoWIl ill Ia bl(1 1 Tlrp Ipsinolls exudate may be jJleplpd in two wayi-i fl liSP as a stallClHld-(l) the clpan exudate is clripd iol Ghouls at ()1deg C at W indlPs of a(lIum Hnd aftclbCinOglOund ill a molfalis 1)I(spI((I intn airtight COllilinel OL
(2) tllP Cx7lclate is clissolllt1 ill a(lhllll and filtplpd PlactieaJlyall of the acetm1l is thpn lYapolntwl olt OPI a stlam or atCt hath and Ow residue is dripd ground an(( PI(sPIld as ill tllp fin lllethocl Tlwse two prepalHtlolls a1( (ompalpd in ta hlp ) 111( (((tails fOl ~t()lil1g the resins standald and (onstlllcting the calibration CUITPS alc given Oil page ]2
lAIIIg fi-CUIIIllrsoi (lJ lIr-dr(1I IIIIi 1((11 II II-()I-tr((l l(sil~ 11111111(8 of I II 1111Ie
[Colorimetric rrndill~s 011 1~I11 phulll(Iclrie eolorillJct[lr with i~()middotmll (100- to iiOIIIIl) fillcr [lnd 5-1111 lIperture preeipitantl part ofO5middotPIrctllt 10 to 5 paris of IIOj
nupliclllc(oloritwt([
nIl(lin~s (hIlSlcAg~ ofSlmillXo JrNliltlCllt of fPsiJI$ L1Xtlrlntp on 2 IIIg ofplanls fllsins (XIHIIlt~Jwr 25-1111 vol
tII1(1) 1
leflTs Various _ bull ____ bullbullbullbull 3-9 Colll)Josiltrlairmiddotltlricfl bullbullbull nf)2 002
])0____ bullbullbull _bull __ _ bullbull ~-l Composilld (ri d at n5 C in aUmiddotimh lWUUllJ for l (jOuj(ja hours])0______ bullbullbull __ bull ___ bull 3-0 COJIlpositld disso]NI in neptolll f1l1erNl fl(lf()ll( GGO i(jO (Ivaporntld olT OV(1r Stpl1l11 halh TesidlH drl(ld I1t fi5deg ( ill anmiddotinch VIl(Unlll for 0 houlS bull
middot106 __ bullbull _ Jir~c1rild_~_~_ _~_ ~_~ _ ~ ____ _ __ _ OUu GOifina_~ ~ _ ~~_~ ___ _ _fln~ ~~ ~ ___ ~ __ 6(imiddotI tiliA H)[_ ltlu bullbull i18 tisSflOabullbullbullbull__ bullbullbullbullbullbullbullbull lt10bullbullbull _ tillO llitO406__ bullbull __ bullbull __ bull __ __ lt10_ Utl2 fon591_ fo__ bull liGa oOa 406bullbull _ __ lt10bullbullbull_ li5S OM
j Ph( vnluls in Uw Inst COIUIIlIl indieatp thnt gunyulp fesinous (IIHlnt( wlwtlwr dfircl hi Yn(tlLJ1l1 wilh L~ perc(nt loss of volntllt wutl pr or tWl c1rild giVPd npproxil1lnh1ly t Iw snllw colorinwtCr rNHiing- 011 till busis of aliquot~ cOlllniuiug 2 IJI~ of flsillS lXIHlntp l)tIf 25-mI volultl( Ihil- illdicate~ thl11 Uw UITW IJ1flS~ of olnshytile mntl(f prt~(iJlitnt(d gins npproxilllntlly Uw $1II1l (oiOfirnl1tlf ftudiTlJs ns tho ftsidtw A pnlill1jllaf~middot (XIlltrinllnt indicutls thlli th VUllltill muller l(lIlSists of thl Ilrplne oil fmcl ion I5-(1Il gtnplls or rlsitlOtlS (lxudntll gnvll by stPll1U distillation nn Uefllgl of 011111 of jl(lfPlIW oil with npproximHte tilllsity (If OHIi lind lhus rrprlsll1ll( IlPIJroximllt(I~ 01 Jerccllt Of t he original weight 1hls lllrClnlage complrcs wllh 38 llltrC(ntlost by drvinI( in IICllnllJ
aSplusmnUH perceilt or orlginlll weightlosl
The wailnble illfolJllntioll on tlH (ow-JitlPllts of the gunYllle r(~shyillOllS exudate alld tl1( HeetOlIP ext act of gaylp ti~slw is sllIllmarized in this paragraph lYalttI (u) alld also Hangcn-Slllit lind his coworkshyers 16 reported that 20 percent of the resinolls exudate from gUltyulc stems is parthenyl cinnamaie (CHuOH=CHC020 11JI2r) Steam disshy
15 (OIlIJIIIIUicatioll flom A T Haai(II~l11it llId (0011(11 Calif0111 ill Tnfiitnte of Tccllllology Past(IlIJI Jhps( wOlken al Htud~ing the COTlHlitlllllts of the acetone extract and other conlltituellis of guuyule
30 TECHNICAL BULLETIN 920 U S DEPT OF AGRICULTURE
tillation of similar resinous exudate in the writers laborntory has yielded approximately 4 percent of the whole as the telmiddotpene oir fracshytion Haagen-Smit and his eoorktrs nportec1 thttt about 25 percent of the acetone extract from guayule branches is parthenyl cinnamate and 6 percent of the bark (ltortpamp-phlotm) extraet is parthenyl cinshynamate These workers fm-thcI reported that 25 lwletnt of the nc(shytone extract frolll bLllllches is a compound with the tlI1pilicaL formula CBoH400a 1 percent is a compound llwltillg at 2P to 2T5deg C and 1 percent of the extract from the ]eav(s is tl (olllpoulld nwlting at 100
to 1710 1Valtei (6) reported that 3 to -l perc(nt of the tI(eton( txtract
of leaves and flowering StPIllS of guayulc eonsists of waxlike substances soluble in olgallic soln~nts but insoluble in at(l and (on(ent1llted H 2S04 The flactions mentioned on the basis of (onHLTutle esti shymates of amoullts actually isolated tlecoullted for about H ptIcent of the totalncetollt~ so]ubles extracttd from tll( guuYllle 11 rub The other constituents ltlilaill to be i(](ntifi(d
RUBBER AND RESINS CALIBHATION CVHES
Typical culibndioll Clllves iol Iuhbpl and I(sins bas(d 011 (ldtLminttshytions made nccoLdillg to the plocCdmC outlin(d 011 pages middotb to 1G arc shown in figulPS 5 and 1+ The spCdlopliotoll1lttL en (OIOIjlllctCI readings are plottCd on s(lIlilogalitllllliC pappi ag-ail1st (Il 11IbblI (011shy
100 ~ 90
80 ~ 70 ~
z 1amp1 0 II 1amp1 IL
1amp1 0 Z
60
50
40 ~ltI 30 ~ en z ~ ltI II ~ 20 C) ~ oJ
10 o 2 3 4 5 6 7 8 9 10
RU8BER IN 25-ML VOLUME (MG)
bull
bull
bull FI(lURE 14--Ctlihration curve fotmiddot gllftYlIlc lubb01 (Hct(lings Oil COIPIIHlII tlOl1hl(
monochromator SlCClrophotolllet(r with 7fiO-11IL Illtel alld Hllp Wll ( IHlll()
bull
bull
bull
RAPID PHOTOMETRIC DETE~MINATION OF RUBBER AND RESINS 3]
centrations From a casual inspection of these CUlTes it would appeltr that Beers law does not hold Actual tests indicitted that Beers law was applicable only within a narrow range in the upper portion of the curves The analyticlil results on the basis of photornetric readings nre therefore calculated by direct reference to calibration curves or from reference tables of equivalent values bllscd on the cnlibllltion curves
Calibration curves for kok-saghyz alld heyea lI11tulltl rubbers and Buna S (GR-S Chem Gum IV Goodyear) and butyl (GR-I Standshyard Oil Co Protoc) sYJlthetic rubbers are hOWllil1 figure 15 The samples of kok-saghyz rubber were furnished by the Diyision of Rubshy
100
90 ~I) ()
z 0
1amp1 a
~ a
80
70
60
s 1amp1 ~ ~ 0 ~ KOj-SAGHYZ 0 l Il
50
HEVEA~ ~
40
100
90
~ 0 80z Q 70a Co)
a 60 ~ 0 0 x 50Il
40 ~----~~----~------~------~------~--~ o 2 3 4 5
RUBBER IN 25-ML VOLUME(MG)
FmUIlE 15-CaJiblation curves fOl kok-snghyz h(YCII Bunn S lind butyl rubb~ls (Readings on gy((yn photoelectric colorimeter with i20-lIIp filtpl and 6-ml aperture)
32 TECHNICAl BUIJLETIN [)20) 1 S DEP1 OF AGrnCUIlfURE
Iwt Plant JIl(I~t ignlioll of thi BlII(un and (1( l))(parcd according to 11( SPltI1((-Culd (]] (6) PIO(((lllll Hlpt pal( CLPPe was (xtmch(L with acetone blI()Ieit W 1I(gt(11l a ttnlldal(l
SEXSlllVllY Ol~ llETJIonS
By lip pIO((l(II11P olltlillP(l 011 ]Hlg( +n Iowa (lOOl IIIg (11 1111i(l0shygmm (gHlllllla) of 1hblI ill a 2)1111 yoltll1ll (all )(gt dltpltld Oil tltl Col(man (lohlP mOIlWhlOl1lHlOl l-I)((t 101 l1lOt 0111 ci( I ill1ilnlly 001 mg of Iublwr ill a 2J-1ll1 n]ulllP Illay bl Ilad Oil till EnI)1I photoshyllectlie (O]oLillllt(I Thll ya lllll- 011 tilt IHl-i- (J I (xl ad iOI1 fmlll 02 gill of til-lI tH(JI(lillg to tllP -lllndal(l jll()(pdull 1(PIPStlIt IlO()2J tlnd 002) P(IT(lIt of llIbl1ll IPI)(((inly bull1t1lollgh -lI1t low allils can be d((d(middot(1 il lIoullt1 Ill IPtllizpd thnt till PIIOl ill PlI(Plltng( or tll( al110unt dltlIllIilll(J i ltlatlpl high ill tili PIY lo Itlllgl 111 aetllllllladie(middot Ill( lopl lillliL 111)(1(1 lIw (ollllil ions of tlil ]lI()(lltlIIIl u ol1tlinpd ipt at l11 11I1 or 1111gt11(1 illt i-1ll1 Ollllll IlPIPltPlltillg 01 p(gtl(pnt of JllUiJtL un tlll 1Hli or (xlla ion rlOI11 II rlll of tisSIll
EIlIlOH COSIIlIHIIO
In Oldpl to H(IIp ill )1lHtPltt pl((iioll illlpIi1I- it i lH((SSHI to slnlldHIdiz(i rigidly 111( Pl()((dlll( 0 illdi(ntpd Oil pnglt- - to J( If lids i dOlH tlip lXIHlinwnlal PIIll is t(middotdllld 10 n ndninlllill
Illlt pl(iioll of (hI ]lIPPllt 1IHllwd Oil til basi of ]llllP llIllJt1 alld Ipsinssollltions call hI jlldgl(J 110111 figllll Hi lileh lio- til HPIlIgl d(intioll oft -illgIP lI1lnSIlIlIIIlnt in lHi((lltagl of Ill( alllOllllt 01 Illhshy1)() 01 lpsins d((PI1I1 iJlld TIl( (1101 PlI(Plltaglt H1( gi (1 101 OJ) to
RUBBER IN 25-ML VOLUMEMG) 004 01 02 03 04
i= I I IZCtOW
fbA ICtU CtCt WW a
01 02 03 04 05 06 07 08 09 100 = RUBBER (PERCENT)
RUBBER IN 25-ML VOLUME (MG) 10 20 30
~ I CtZ
bBOw Ctu CtCt Ww o I~
010 50 100 150 200 250 RUBBER (PERCENT)
RESINS IN 25-ML VOLUME(MG) 10__ __3-0_ 40 50 60 70 60 90 100--_-- 2_-0
Ct~ -r- 1 I OZ
WCt UCt b C wCtW
a o I I 150 250
RESINS (PERCENT) o 10 50 100 200
bllI 1tI W-Yllnl dtd1 ioll I I 11l1 11IlI11 1(111(11 1 III Plll- IlIIIlol1 01 IIim~
bull
bull
bull solution Il basis J o golH of tiSSII (JlILCl-nt (11(11) for (~I) (l)1 til O 1I1
of luhllpl lin 1 III I (I Ill of lUhlJPl nllll laquo I J to 111 nlg of IlSlllgt (Itllillgs on ]iYllyu pllolwh-llrk CO[IJlilll(-(PI with nOHIP Iiltlr lIntl U-lIll allcrture)
RAPID PHOTOlJElRIC DELEHlllNAllON Cn HUBBER AND H1~SINS 33
10 mg of rubber anel1 to 10 mg of resins in a gJ-m1 yolumC For
bull
bull
bull
comparative ptuposes the leslllts arc also calculated on the basis oJvershycentage rubber OL tltsills in 02 gllI of tissul As WOlllL be expcet(d the error increases sOIlHgthlf for 1(lali nmiddotly low COlHell t1llf iOlls oj rllbbeL or resins The curves in figure 1(j s1l0 that ill til(gt Illlge Ol to 10 pCrshyeent of lubber the elTOI rangts Jroll1 abollt Ll to II) ]IlC(lIt abo(~ this mlllc tIlt (ITOl d(((ts(s to (ollsidlItbly ltmiddotss (han 1 1lICPllt of tlH mllollnt ltl((Lmill(d Hil1lilally in tlH (lISl of l(sins analysis (fig 10) the ltLTor is (onsit1eIubly INS than 1 PlLllnt ill (he lallgp of 11 t~) ~() penPII t
In nil ([lSl of lllhblI alld (sins lx(Inltpd tIOIl1 (issups Ol addcltl to tisslle lxtlads (s(( tabhmiddots (i H) illyolillg ll01P o(lllntiolls the eLI01
is hig]wl thun that indilHtld in figllll ((j Im pUIl Ill )])p I tllllllsins solutlOII
COlllUCIIOXFOH IXSOLl-IlLl~ Ilgsqgt(Jg
111 th( Jllo(pdulP ollllillPd 011 paw I till illsolllhll isSII Ipidll( tflpl (xttlw(ioll is (Ptill tlw lIask l(lll till xtlct i l1wdp up to yoltlllH It is not rOllPllipnt (0 IPt()PI qWlIltitati(Ir III(lw[olH a 11(1 pllooll extlnlfs of guuyull I is-lll alll thl1l main t11l111 up (0 YOIUllllmiddot bpCaUHI sllch all additiollal stltp wottld]) tillll-C(JllS11ll1illg Th( Iogiea nll(gtIshynntin is to mnkp tltl lXtlUCt Llld Ipsidup lip to OllillH in till original flask andi llPSStllY 10 llwlno tl OIIpdioll wlHIl (allIlnting [hc llshy
Hults f(JI [hl oll111lC displupd hy till ins()lllbh llsidll( III it l)picat (IXpednHllt (ollsisting of Jhp lppJiea(iolls if was Iollnd llftt at ~iiO ( 02 gill 01 Iuhhll pillS IPill-fl(( lisslI(gt (lollpdll fot llwistUlC ou basis of dlyillp ut lOW 101 ) llOlll-j (lbp(ld only t~ llllUll voiul11P of OOk7D~- OO(lOO(i Ill of lllthyl bolnl(yl 1lIOll( (lplhlli(al-t(Tnltle sp gl () Ii I ll(Hli (j at ~)) -gtitllP tl1(gt 1It101111( () r t is-lIl xt Iadld j sl1lall til( PlIOI dul to Ill(gt insoll1blp Ip~idll is slllall III [0111 ill( wOtk it (all lJp diIpgal(ll(l
]hcon~lIY OF HllIllgl AiO HESIS AIH)gl) TO EXTlIACI OP
GlYlLE TISSlg
Tnl)ll G L(IHpslntillp (ypi(nl llld(~ SllOS (hat all a plngl of HIOK PlI((nt ot lltl pltl( Ilhl)(l acldpd to tllP Itll h iolJut1 InmiddottcJllP xhnet
of guayulp tiSI1( WllS 1l((PllIl Tlli nllintioll flOlll (olllplpU I((OYshy
PIY i within flll pxp(IiIlHuttllIIOI ~illli]llly fnbll Ii llows thn 1111 llYlIUgl of 1O(1~ ])(I(Pllt of gllllYllII 1(-i1l- add(d to II( (pllosol( (xshytrae of IUllY]l t i~HI Is 1l(oPIPI
THl~ (~ Hf (Off Ill of 1111)( J OJ I~il~ lItfI(( In ~(JI1IJk~ Ilf (111 [lI1Il fI2 lIII
0 tlUfllllit i~~I1
Instrument
---- ----~---- bull shy 1(1
Colemun ruono~ltrOUlllt()r 2t) II sJl~ctroJlhOL()lIIeter with 2tJ I iflllllI wnclength Fetting 21 II nntl 0-1111 WU HI hUJl(L _ L U
Ill 7Evolyn photo~lcclrie (olor JU [ imctcr with iO-llIl filler IV (I
H1 0 t I I
llImiddot lUn WII 1011 HIO Wn mil lUulon
10 JIg1111 IUI ml lUl anh Io aLn 111)_I ) III li lU It 2) deg wn2SU DD
Irl JIll II IIr II US II
1110(1 lULa lUI IlK) IJ WU
I( llI Htl tNI 1(111 2tlNI HI 0 221) lllil t2S 0 1~ 10 1~13
In (I 2117 I
10U 1l(J ~ 4 _H_j ___
9middotJIlJ5 10115 10 00 lUU5 flUU 4li (tl03 9(11)
leIlKl 1l~)5 lOOU l1KIr JOIS un 003 OIl Ii
34 lECHNlCAL BULLErIN 920 U S DEPT OF AGRICULlURE
COMPARISON OF PHOTOMETRIC A1D MODJIoIED SPENCE-CALDWfLL METHODS OF RUBBER ANALYSIS
Guayule samples were analyzed by the photQ111etIic method and by bull the modified Spenc(gt-Cnldwell mcthod The values in table 7 represhyselltativ(I of typical results indieate It -atisfactory dcglpe of conformshyjty between the two methods in thl range of tiSSlHH with llHHC than OJ) percent of rubbtImiddot On the bnsis of the amounts determimd the results in this runge for the plmiddotts(nt lIlcthod ayernge apploxinHltely j percent highcr
~LAIII~ 7-(oIllJl(i~on of lltlllrIic (IIri mOtllinl SJl(II(r-(ulri-wall IIIrtlwrl~ of rlrrlIIillillfl 11)1)(1 COIIrll of UI(III
1 Flowers frllm amiddotmonth-oltl nursery plants
YAIIIATJO- OF SIli(LE DETEnt1NATIONS Fnoll TnEIIllIEAN
Rllbbel (Uall8i8-Thc plcCision of thc pLcsent method when gunyule tissues Hr( nnnlyz((1 for rubber may be j udg(d flom I Ill datil presentcd in table H TIl(se dahl -how that thl pplCPlltag( uriation of single determinatiom from nwan yullles with low standllrd enolS ranges from less than 1 to 4 p(gtrlent
R(8in~ wWlsi-r-s lndi(a((1 011 page ~j he INntlts s((uled hy the present phoolllttric nsins llHt hod are not tliltly (olllpalable with those of the grtLVimetri( ncetol1l-cxtlt1(tioll II1etho(l Thjs made it necesSllry to selc(t another lalibllltion staudud-tlll Ipsinous exullate from gullyule shrub-thut gies relatively COllstlllt photometric readshyings (table 5) The resin (olltents of guayule roots branchcs or leavcs usually ran(~e from about) to 1-1middot pelcellt The ple(ision of the present methotf WhCll gUHyule thslllS lIe analyzed for reins may be judged from the datalHmiddotpscllted ill table 9 1h(se data show that the p(lcelltage variatiun of sillgle lhmiddott(Lminntions iLO11 meun ynlnes with low standard NTOrs rangcs from about 05 to 4 percent
bull
bull
bull
bull
bull
RAPID PHOTOMETHIC DElEruIINAlION OJ RUBBEH AND HESINS 35
IAIILE 8-luriation inclieute rubller (mallSM of [1wIIle tissue bll thc 1111O0Illclc metwII
Vnrlntlon~Ilbher I (rom mean
ierCtnl Percelll ~OU -22 ~ 25 +27 ~ 20 +18 ~UO -22---------1_______ 51110 0G6 bullbullbullbullbullbull _bullbull
10 ro ----=ii41075 -01 1000 +11 1010 +13
rlln HI itil 1l9~ 1_ ___ =-~~~
115511 ~ US -111 III II 1575 -13 115 b tiS -I a 111 h WlU +22IIM-(middot bull 11K -1Ja Illi c 1000 +03 1J5H1 W +l)7 ll1imiddot tl 1575 -13
Mcnn 15951 131
1102-11 21fJ() +21l102-h _ ~~)SO -17 1102-c bullbull 21CO +21n02middotd ~OIiO -26
2 r~plusmn Il~ 21151 261 I -~-------bull---__ _~~_~______l-___--_
1 lhe$ 1111($ I1n (or SlIlIIllltS Stpnnltplr PHrilClld IIrtlrdlng 10 1hr prollIlIlr( OIiIIiIl(o(I on Imgt$ 4 to IC ~tcond nUlI1 hlr r(J)[ltnts stl1ndnnl llrrot of tilt 1I1(1111
1_1l1~ n-J(lri(iot in relli(Upound rpoundsins (lllalIsfs of VIOJII( lixsue b1 the lhomillric lII(lloli
-- ---~--- - __-------- shybull I I I I Varlgttton
_________~___ ~~lu_n_Jl_Q_~~~_____ ______I__~_o~S_J frOID lDean
Percent Percentgt458-1 ~65 +41IWtl-li 130 -a2Hli8c aliO +26S41i8-d bull 130 -32
1(-011 34I10Olifgt __ bullbull __ ~--====
li-9~2n 881) -06 li-9~2-b Si5 o ~HH2middot(middot S i5 -6$-H2middotd 000 +1
8851 054
O i5 +6 9 i5 +6 950 -20 U75 +6
H-liG3o-n bull -1 n-li6~b bull __ _ -IH-IWH +4H-l61511 bull -1
1tmiddottlU
62~-lI __ 62~-b ij24-( bull OH-Ji
(-Ull
I rll(St oluls nre tor separately ~xlrflCled SllllllllCS IlctOrdlug lO procedure outllned ou pages 4 to 10 i Secoud number r~prtgeulS stulldMd error of lIe menn
36 TECHNICAL BULLETIN 920 t ~ DEPT OF A(]RICCLTCRE
ReUUER A~ALYSrS I~ CRCOE-RcuUER PROOCCTS
Sew rapid photometric m(lthod~fol the ddellllinttion of rubber and reii Hi ill uaYllp ti--ut htp lllell pIPHnl pd oil pag( ~l to In A brief H1111111tlY of It similar rnpid llHthod fm 1I1hb~rllnltlysis of u1lulcanizNl tlIldp lubbll pl(Hlmtlt whielt i~ bn-(tldo on the prill o
ciples dehtilcd tlllLe follows Duplltate nt-gm sllmph of the finely cliyiliNl IlInttlitiup wlirllll out [~ei-()l (all hl lIf((tinmiddotjv INd to lt1iyidl till alllpl) TIll kltolll-olubll portion of till )111(11( tlrc di-olved a- indh-Htpd fot thmiddot lllnkill~ of -tlllHlunlluhhll olutiou Oil Pt 1II hut tIl IUlIp Hn lIn l-fplImiddotd 10 lHI-ml rolllllltti( fln-k antil1ltld(lup to Olllll1l The bnlulUp or till JllO(ldllll i- thatutlilllll on paWs -1- 1 IHI Ii 111( 1(111 1- nIP IXPIP--pd nil til IHi or Iw oligiJla w(lullt of I Ill (I11l1p-I1l11Ilt1 1)(0(11(1
Hupitl PlllimiPJojgtiWllllllllh llIltllOd~ fOJ Ihl llPtlmiddotminntion of ImiddotUlJbll tlnd 1(-illo- ill -111111 Illllph of gutlYllll tiUl IIll dl-eli)ed 111() IlltlY d~o Ill nltlI1lld fOl III Iwl Illhlwl- and l~iJlmiddotb(lLiJlg plant TIllt l[Olllhup hns nlo b(l1l ntuptpl fot IIH lltlIll1illtltioll of lllhbpl ill 11lHhrublwl Pl(Jdlld~ HIIl 1111 hI ndaptld JoJ IIll ann lysis of ynt1J(gt( ic lllbbl[- The llllthmb HIP 1gtn(11 fill tIll fol1owill plimiph- III Grinding
tIll PIOPlly driPl t i~lIl 01 Ul tillg tIll pnHhHt to tll l((lllilllllh~lel of filWlH-- til plllllit qIHlIllilnth( lXIIHtioll 01 IIlbhlI 01 1(--IJl- () llsing oXWllutld olnuh (kttoJls IIt(talp and() fllltil for LIbbel and IH(ltIlIlyptIJllIllIoolYlnJld-o flJllh 101 niJlsl with t(lathelr high IlPililig points 111 to n C) l]olle or in mixt tIll thllt Pll mit tlll rnphllxututioll of luhll(l OJ [middot(ill ill ~() to (l mi1lutp It r(latiwly high 1lllIllllltlltP Ill to 1~11 ) l) lllllipitntillu till luhblI OL Imiddot(ill frolll aliquot () f till oltn ion I IlIlllI-i () f Hlltabhmiddot pl(~(i]litallt (willifhmiddotd lthmwl fOl IIlhlHI Hild llitlifild lllr fOJ JP-illl t~) IIlHkillphotollllliilPIIIIiIlof PlllPlltal of liht tLaIlS mittUl(P lIftlI IlIlbll (II Il in PIlipitalioll 11 II WI( Iplllh thnt (limiJlall till PIIOl dill 10 xtralllOlh (0101 (till dptl1minntinll Iph jill 011 tIll dtwlopllIlJIl of H HIli rOI1ll tlllbidity 111 hpl than I (olot rI
jJlIlpOP-ofallnlyi-I ( p(lllil1thb IIllijOI1ll turbidity or 1llt[lIinmiddotd d(ltl of jgtIp(ii(JlI l)~ lIltlkillU tIl plllltollllmiddottri( ntdillU al tandinu tiJlH~ (dlllilll wlli(h IhlllH(lill-- IP 1llutinmiddotly tnhll) t1ll1t an hlsl~1 oil the (oJlItlIlllItion of IIlhlHI Ill I(ill (lIPIipitat((L
TIll -I(p ill till jll()(Plhul HIP 1-- follOylt (1) 1l~UIIL uJ1lplls of thwl UJfJlllHl (II tliddl(l HUt dlipd 11Illtplial an lXIllltel with11 Ill of till nlnll ill t (oU tlllltIPlll[gtPImiddotatlup oil Iath at 11 Cbull fol 11 minutl I) iIP1lIin(middot(lohd til( (XUtllhllll Jltldl lip to It middotml ynlmlll til( (nlifild by (Illlifllgiuu HlId thlPl IlI nliql1ot of tIl (IalioPlllxUlltl nll Uillltlmiddotll(t to l-llll OIlIIlIllril fiuk- (1) For a trial Ilnditlg 0111 III tlll j liJmiddot~t IllHII IIjI to Ohlllll with lilt Pll shy(ilitnnl a 1(11 it 111 (Dod fill llli lIut ( ptotoJIIltlil IPtlllillg-- of pllllntnl or liuht tlUtllIlillal(I oil n (lpel OphotnJlllllI at rase hng-tlt (If 11 llJ Ill Ol It lollllil1lPtImiddott lloyidld with tIll P10]11 I 1110110shy
Ihlolllltt hmiddot Ii1llI Olllhi lIatioll for -1IpItillg UJlproXilll1l tply Wtl P ]Plwth )0 mp are HHlltk TIll Illldillg lliJtaillld fol tIlt 4-milutl tliall(~ll-
bull
bull
bull
RAPID PHOTO~IETRIC DETERIINATIOX OF R(BBER AXD RESINS 37
ing are referred to a table of equhmiddottllut~ previously p1(pa1elt1 on the
bull basis of 4-minute reac1inJ~ for tilE nmge of lot1telltlatiol1- of rubber or resins to bE elHOlll1t(led tmd gidn thtmiddot -tnnlillfr tillIP fill rUbbEt or resins aiter prE(ipitlltiol1 lwfolE photoIllNliI j(tltlill1 un IUade The r(middotnmining dllplllatt aliquot lll then HHllil up te ol1l1Jle and lpoundadillg ale marle ut the -tandillfr tiUlE iudklltll ill rhl tall1lmiddot for the final r(adillg~ -1) 111( milli1lnm or p(tCPlltllt- of lllhbpL (II 1(-in pr(s(nt are rpadholU a prlpan(l table of lquiltlput for tlll photoshymetric readings h1~l(l ill pnell e1-E on pxpPlilmlItal lhln 1111(1 u-ing as stimtlltlds pure luhbll in 1l1bbtl milllYb aIHI guaYllh ll-ill- lxIHlatt~ in resins detNIl1111lttion I
LlTERATlRE CLTED
(1) lUnSbull 1fl36 THE mURMIXTIOS IIF IOTA RE I III OOl THER llT~II
F1 bullrol IlY U(T1l0fll UfSlfi ~rrnrl r flm lt1 KEYS TI Bill Chern 114 44J-l59 illns
t1 ~ICPHHlObullbull T 1J3bull~ lUTHOO roa THE PtRInCAnu Or a(lIUl IRrIlHU It of TIn
PLRIHEU Htllllflt [ i Bill lallllall 111 Rmiddot 711middotj iIlus
I ) RHBERG P B Ul5 A METHIlO Or ~u(ronrll-nl Hi tIII rUIl[1 f71 ii illlI
bull 14 Hoss W flbull and HARDESTY J O
llH IR1ltDII Of HfITilIZfmiddotR DllIJS ltt 1 Yl fll Off gI bern JIIIlI i ~middotmiddotlf IIl
101 SPEltCE D nnd CuoWELr ~I L 1933 DETER~n-ATIOo OF RtBBER Ii nrllllpoundRBfR Iusr 1uI II1 amI
Em~ifl cttIliIa~~ r Ell i 71middot7i l11 (HI WALTER E D
1U44 ISO~nlS OF PRTlltSrr 1trHpoundV bull l UI n W lHHt (Tnmiddot 1ETS FROM GiYI l~iIl lItr Clttrn SII J UI titJ middotn9--C1 ilIu
17 J YOEbullbullr H lO~( roLORIlETRT 771 IPmiddot nl -W Yurk f H Plrwptric hmica
naly-II rimttry lUll XphHHlnmiddot~ y 1 1
11
HI) ~ fPHELolzTRf 57 111bull Lin xw Yk t H lt PhmeHt CblUlmiddot ila AnaiY~l~-(H lithrry and XIhmiddotILpfIY Y wirh enomiddot rrJlllrjr hy H KtlJnJU11 I
t~1I --- and ~ARVER L 1f41 nlua-w ~in L liLhr IS IP ll~ XIW Yrk
bull For-sale by th~ ~a~fr1nt~nf1ent Dt~c~~ogtnts-~ s t1i rArnn~ut Pn~~~ tJffieshy
Washington 5 D C bull Pl lU ~nts
bull
bull
bull
RAPID PHOlOMErRIC DETERlrINATION or RGBBER AND RESIN) 5
drying oyen hen the samples are yery snlall minimum umounts at tissue in wry small weighing bottles t35 CIll high and 22 em in diameter) are usee to (Ol1SNTe ti-ue The sumples pound01 analysis are then w(iglwd Ollt Oil tlil llalis of (onsl Ltlt dry weight at 1000 by using the factor fol 1l10isttllC COIlP(fion
lJAGE~TS FOH RtBBEH AlALYSIS
In a l111lllbpl of eases in tllis -(cti(Jll nnd the Olle on Heagents fotmiddot HesinLllltlvsi It(llllilttl-gltlde dlllllieal whielt were the best obtainshyabll during tIl Wlll])(gtlio(L fLtP indklttd These proed adequate but wllln b(itleL glatils HIe inailahle tIll) (HII he cl1(gt(ke(l to dcleLlnine lny adntntugts of lIbsl ituting p gllltlps rill nbbpl and rtsins soh-enls HIC kept ill glas--ioPPlllll bot Lt
Sollenl~-Methyljs()lJlItyl kl~t(JII(gt t(hnicalgrllll lIbOIl amp Cmbide Chemshylenls COlp is (nUlply latiII(tOIY fol 1I1ltuIHI 11IblJl1 lt is IPportell us appalshylutlr Ilontoxie UI) Although it has thp (IHIIl(fplJ it IWOIll ollor this is leSS IllOIlOUIl(ld than that of othlr IHIOIHs ((Ilsfnuls fol this lIud other rubbel -lIlrellts art given in tuble 1
lAlllE l-Propumiddotfirlr of Hfulr drubIeI olld I(~ills SOllCllts completely soIlvie in 9JpccI)Jt cUtawt
olu billt r (reshyHnilmiddot lation to weight mg ~yenI~NI~ I at (J0 C)point ~1hSolvent FOrl1uh (Ill llOlnl (IIlII(l
lUIIl ruhber 01middot Wut~r llg nlI in lusomiddot
wlter vent
Hubber sohcut c c Benzene l _ elf ~nl ILU olulole ~[NhYI iobutyl k CHltlH(JIC(J(H II 23V do
tonl LNbyllHlfllyl ketOlw (If c1I3IUIllUmiddotoCli lW r 4S U _ do 43 1 1 Diiohtllyl kNone ICH([JemiddotJjlWmiddotU(ll(I1 11 fln 010 06 45 Butyl nCltllt~ (I1roeJ(I1 12fi3 a7~ do fiS 12 ~Iethyl amyl atNnW (ljCO(j(lH1 (Jl(J1lIJ 1 IIi 3 131 lt10 13 1lS Ethylene ~IH-oI dimiddot CjlJO( HtI1O(fh _ 121 I 3J () 110 210 3
rtllyl Nlllr ~middothutyl (ther (ThO Ih 112 37 ~ tlo 03 19
Rcsins oh-cuIsACNone I _ clI C()( If I -~middotI lrNiuhll I()() 100 cetonylnclonp Cn (middoto(JJcHlt()(I WI I ~H tlu UKI llJO EthylD( glycol mollmiddot CHUCUCII0H 13[1 rl2 _10 1(10 100
oNhyl Nher (((lIoshyFohc)
Diethylene gly(ul 3u 7 1111 ~flo lOU 100 mOllohutyl Nlltr Ibmyl carbitol
I fncllulbullbull j lor rOllp3rison lnly
RIlJJIIJ1J( (illituliIlQ SOIIIUJII Oi-I)PtcPIlI n~() (c ll rellg(nt Ill Pont SP gr L~H) oluUolI ill JJ-ptrtPlI( p[buJo Ily ulullIe iR upd as a lUlJbel Illpd) tall r
lrue(it-c Colloid SrltlioJ for RIlJIII A middottipcImiddotPllt iulutillu of diglycol stellshyInte S Or glycu~ttlill a retllJld g)1I11 ur tlid)(middotul nlmt Hot llYailllbe (luring the war pellod) (bUIll tlellnj(IIImiddotIndt Ulycu Prot ItI (middotu- I i IIllHlt ill lIl0lj)homiddot lille (lecbniC(ll-glu(p EusnHllll I TIll slJ(k ur digl)( [ptrlltp ~ ued ill these expfliruellts on till bUSh of tim (htPlmiulltiom nt iJ C IYIIS illO(i 1-ereClt solub( in lll()rptvlilH) rlJe diglyt1 f(Ulute 8 i blOght U(II lllutiOIl by heating tll( oluuolt is made up 10 olmn I t a tandarll tllllf)(rtltUle (25middot
J Z30 King ltrcet Brooklyn N Y
6 TECHNICAL BULLETIN 920 r S DEP1 O~ AGIUCULTUHE
in the Writl Inborntory) al1l1 fiUerp1 A [j-I~re(gtl1t solution of this by volume is then made it thu k(tone Htptate or l(hPI or tht llIixtlll or tlH~p I~lll as tlw lullber foinnt
REAGENTS HHt RESINS ANALY3IS
Resins SUITIIN- Illixlule I)f a parIs ot lll(IJII~lIllII(JIll Hlld j pnrl~ (If fthSi IllI glnmiddoto] IlHlll1I1thII Nhpl (l(rtiIlHft(l 1CPIlPi i 0 as (middot110lt01middot1 I hr 01111111 botl t((hni(ul-glu(p CnlilOlI amp VHIhi((I h(lIli(d~ COImiddotpl is a gooe1 r(sin~ soiYPllt ~Ihis lllixtlll(I i~ 11(111( (0 ilS 1((loll~Il(ltlJlIPmiddotllll(Jllmiddotl amiddotmiddotj ill thl ((xt (011shys(allts I)f thf~( a 1111 011](1 rl~ill oYlll(s tn )inlI ill lalJl1
R(IIrmiddotpimiddot((middotJitlltill1 iWiIiOl- [i-(J(middotl((middotClImiddot 1I~O (e p (agln Oil Ponl f1 gl 114 J solul iOIl in HO by 0111111( is UStl m I Ill llills pll(ipita nt
Po(- i ( (ol()icl ~lJ11I1 iOIl Ol t(8Iyen-A O-IlPI(lnt olnl ion of (igl~((1 Rtrl ra i ( H or gly(o~t tlill I lIIath ill I (p( ollyln((1 OIl(middot(plJool( j or nlly ot Itpl rlsills solnnl 1I(tL TIJl diglYlol Hipn Ill ((i ~ is (lis~nlaquo hl 1 Itll tillg Illl lolLttioll i 11111111 liP 10 ulnnl( nla Ht1li1l1H11i tl1Il1ltIIItlllP Hilt 1IIllI((1 If thl -oll1liol1 liOllltl )(lOIllI loud) II((IIIP of II drop in ((IIII)(IH(III( 11( plPtipinll may hI hlollgltt IIHI ito ltulutioll hy It(lItill~
SIECIL EQrllIE[ Fon HlIlImn 1) HESS AALY5IS
11I0T())t1~TIG ISsTH L)IEITS
8((1111 tylllS ofi IlstllIIllllltS i Ill 1lid i Ilg tltl C01lIllflii e ] (((Ioni( plW((lJl tI OJOill(hI (oJ II1Illll dolllJltmiddot II lOll el(h1011111 t OJ SPII( IOplJOtollwtpJ Klett-Sull1llllrSOll o1olillltlI and EnIYIl pllOt(l(h-tJie cololimettt han b(PIl II~~(I TIll pilotoflttolOIlIltll apptUPlltly is llot suited for thl pUlposr iJltHlIP thl (hllJlIh~Jjstj of n( l-ollsplllliOlI IlHHStl1lll waS SLl(h that thplp WlIS velY ltLpitllhullge ill the rendingS oil standing of the liOlllt iOll a1tlI rubbl1 nnd Il-ill~ plltipital iOll fltP onitL of prefmiddot el(llce fl(lIll tilt ltalldpoillt of gllntls pllri-iol1 of llading~ is us follow
(1) CoWlIlan dOllhlt 1ll001O(ltlIII1lH I01 IWl1 Iuphllt 0111(1 PI mo(hl lOH 0 COPIlHlIl I1I1iY(lsnl SP(ctI1I11holl1nHt(1 Ilwdll 11-WaYlmiddot1I1g-1 It Rlllinl II t j() mLL is IlCIUlIllPlldl(i
(2l EnblI pholo(lptlli( (olulilll(Il1 wi It (Ining- 1II11 110(IIIUIlHl tie filt lr rOIllshyhillatioll jtl lIllL 12middot112UGc51- villstllt (ap i~ ~(t1 10 ((Jlr nl)lOIptioll IIt tllllP Wlllll 1(IIilll~ HI hlill 1lI1lt1t A nitmiddot fill holding 11 Itlllll nmgllifing IIHli til flllilitatt lIlaldll~ IIPPluxilllllll 11llIII11111letl1 I(adings tn 01 lila) hc IIJ1l1l1fll(lllld 10(lllIy
(H) KlpttmiddotHlIIllnllISOIi (OI(lIilll(tP-So ~Ililllhll Iiltpl (lInrllinnlion of IIPillllXimiddot nwlcls 50 IlIJL IIln( (Ilgth I atillhl( at 1Il(middot~(middotIlt Till ill(ItIIlWllt IWIfOIIlIS Hn tisrt((oil~ wit It th( IlIa iI II 1111 filt hpi ((11 iji 111111 njij IIIl for IlIlIlI(I II nIl1~si on 2-S(tllolll (Jl oltlll glltllh 11111 (prilll wit hlt l(lJlo((1 a 11(1 f(IJ~ currentmiddot plon ~1(jlh (101l IIII plnn[ with 111 t (1 ahlllp W(J IllJL 1l( lig Hl llIi 1illlit it USP(IlII(S$
ltOl the JlJ(~(Il( tlt( Ewlrn pllOtolIl(1 de (oIOlinwhl i 11(Olllllll1H1(d as (hI IlOt eOt1PlliPllt alld ndaptabltmiddot il1trlIl1lnt rOl rout illl lnbolttmiddot t OIY alltl ly~(-
OTIIEH I~QUIII~YI
A lhplllIoI11 i(ally (oll(lollltl tlil huth wilh a l(llIun1l1l (1(11 hllsk(t pllllimiddot liOlWl [0 hoW il)Il YOllllllPI( lIa~k~ ltig ] L llihglmiddota(]( tylil(il oil ~ K O i1((1
A tlt(IHW(1l tielHr (mil 1lIl1td 111 Ipl 1Jr t It IIIIIjdlt wir It lHolol iImiddotI(1 Illld IClllollhl ~(lllI IlIl~kl[ 1111 lt it jllll(( t h()1( i II Ill ltlOmiddotml Yonnrp[ riellllisl)I 11( in stnlltIItlllllg I Ill I lPlI (II 11 of IPII)(l1tlt Hila IIn)UIII of (xIII(Itl saJlpp~ Illkpl1 (01 Ilnlll~~i~
bull
bull
bull
7 RAPID PHOTOME1RIC DElERlHNATION OF RtBBER AND RESINS
bull
bull F1(rJm 1 ~ UIIIltan 11l~IIlInIPIII lo UIIlallt-lllllplalul( ~(II(Inl-[lllrpose hath 11fil1l liS au oil hath Xlltl ~IHinl 1(IIIOIullll win 1Jt[PI 101 holding ~[j-lJll Yo1U1l1plllt flask dUIlng- (xu iOIl ur luJhl t IHI IIill IlIi is uot stlludard ltfJuillll1ll1t nIHl 111lIt hi 1Ill((1 b1 (hI Hllal~-t
Ilm1ll E JIItnslIlPil iIIit (111([ (Iltaslll(11 [1111 In(J nlHI K()(lak electric tinwl Ilw Hutpl H~ 1l~Id ill I1PIIIllIillillg )1IIIdillg (illll n((uInl(l~ 111 111lt minute unll luhllpl HIII1 Isllll al( l11(ipIIIIlP(] 111111 till tOIlIlPI 101 tinling hlHtillg nml (11 tli fUli Ilg 11l1iulls
AWill~ 01 It Ball amp I(wpllluill fol Ull initial lWUSI glinllillg of gtllyul(l UsU( Hoss-llal(]pslr IIWllifillIlioll of Ihl lInlllllHI 11Iil I I plIlIilll] with Xo 1
(~middot1Il11l) nl1d XII (iIIlIII1 (lPIItS LYIPX i lUl(l lOOmiddotml oInllHUilt 1IlI~ llloidltl witlt grolllHlmiddotglns RlOPflllS spr-ial mIIIi 11lx ItitUllIti IIllIkll wllh UIlI illlIlp 1111111 1111(1 gillS
10(1 12 CIIl iclllg h~ 1Ii jlll ill Ilillllllitl wHit gtOllIHI UnllIIPti IlId 1 em In dillllllll fOll1~p illlllllldllg lIbhll slutlon [fig A IUHllJ) 11)( jllpiul heakcr I lIJIIlI1fIIIIIlII11 t101Il Ihl W-1l1I lldUiIl low-fllllli 1IllkI wilh s[lout laquo(olning (llas WIllk Xo 11111(1) Till ll (toul I flatlll1lt1 hr (Ill lgl1lu glllliliIIOl[ing Plo(Il1m Ill IillltllIllI 11111 of Ihl gIllgt ruti aIHI IIIP sUIfa(( lit til( lIat insitle hottnlll of IIII )11111 nl( gIlltlIHI toglll)I wilh Itll(I~ ill 01((1 II) s((Ule the most II tisflnlory SulfH1 rill lil Illl I iOll
P~I(X WIIlIIt glI III 111( ll111L ill thilkms 10 II~( a It tIHS(~ III ([hiding luhl)(I Sfllll[llp
A Iolk Imil fill lISI ill diiltlill~ luhI 1111[111 H(Hy(Inl~ 1~T(lX 10middot1111 gllhmlllI (Pili Iifugp t 111H Ill]lillld wll It (011(1 1101111
lind (ork tupp (0 tit I Ill 2 ()
bull Filt1 tilk (fig 2 IJI 101 1)( with Ihl glltllunlld tublS ill thi o[WIati()n of
llOUling lIIIlillpli lx(nll illf jIIlI )lhIIIl1IY(I lIask IYIIHIlt ([illlluin l(slmiddot Ill At hp II11IPI a )Iuss lOI wit h I tIaltllll(l (lIll lIlS lI1ullIfnlul((l ill the Illhllln(()I~- fol this l1SI bill ii In (lilli(ll1t 10 -1(111( II PIIpound((( tit Howlwei tlte anilnblp filtpl ti(klIt1 tlll 1)111)111-1 lind was Intll lIhs(i~llll(l The fritte(l glass disk SII(S 110 rUlli1 lUll Ill llIlI in tliH O)IlIUlhJll hut hollis hlllk the liqllid II nil lPidlH in till ((111( PHill
Cuullipl(1))ipp(ll for tlllII~flJItng klotlls nnd uthI IlIgnnk Illnnis SlIInl pighin) III I (h li (Ill high alHI (III ill ([111111(1
8 TECHNICAL BULLErIN 020 e S DEPT OF AGIUCUUlUlUJ
bull
IHHH middotmiddotmiddot~Ollll of the ~Jl((iHI ~lnsswlI( reshyquilpd 101 [lh)lI and I(sills tllal~sis (lllss rod wilh lInttPIH(] (ml Loll alld tlitulatioll lJlll((I II]) 101 liSP ill bull IIlnlln~ sto1 solutions of IlliJlPI (olII1i lwanshydlltr -AIIlI lYIX ((1I11ishyrllg tulJl wit Ii 011( poillt (0) nIHI flIIpI stie ( J) I fOlllSP ill P[)lIill~ utl (llIdiIli (X( lels witlt shyout di~tlllhill~ the inshysulilhll Ipsidlp
bull
Glns pound1111])(1 ) jlllll in ((iamptl for 1( ill tltlm~rprljlJg- pighpll fllJlplpS HIIl1
bull (lnrin(d IXIIat to -llil ohllnlllI f1aI~
i(p-mollllt gingt hntl will llntit OJ 11I(lal J(IP (n] fOI toling- gIollIH plallt samp(
Halmiddotk for hllldhlg ill-llll middotPIlIlilnp nlHs IIIH ~i-1I11 YOlIll1pllit flll (Jig- 31 Alltolllnti 10(1-1111 ~middotI(lX IlIllPUp of IhI fq)p llsltd fOl Iitis with intpl(middothallg(middot
nh1t H(JlIlHI joint 101 rl1phl lPfIPIIIlg (lj 1lIhhpl fllld 1(ill lll((jpiltlllls
bull
FllilHE Had Iqllind fool IIJI(lill I 11 (111111111laquo llllmiddot alHl (I) limJ VfIlIlllllJi( tlak~
bull TIll itl1jHlIlWI of n Illb tlpl of d(Hdill(~~ III [gtJ(Jtnllllllil lllll~
i dblmiddotwmiddotpt hy Y (J( I _ j J i) t Illt riflllmiddot t tth~ n n Ii 11 111 h111 I t1loOIlldy witl nap lllltlIHI 1111 1l1id bpll tlll- HII lill(ll with (jtt11lill olutioll Hlld ltll If fla k It It [lllijljtnlld 111bhll nl
11ill lIll til ~tlllld all 111th Ill lillI Illmiddotforl 111l In 1(11 it j~ luhmiddotjlIll] 10 1111 0111 ilH (111(11 11[ Jpli~ Ii tllp wall TIll
10 TECHNICAL BULLETIN 920 U S DEPT OF AGRICULlURE
25- and 100-m1 volumetric flasks arc rinsed two or thrce times with tap water and then with cleaning solution al1tl watel as is customtny In all cases the rinsed glassware is dried in an inv(ltell position at 100111 temperattlre 01 upright in a drying oven The flasks used IoJ extracshytion of rubber Iron1 kok-sagh)z (Talllrl(((IM1 kO-8aghyz Rodin) are finally rinsed wHh the solvent to be used and are nllmnd to lt1Inin and dry under a ventilated hood Cuwttes 01 absOlption test tubes nre handled and cleaned aH directed by the manufacturC)s of the llhotoshymetric instruments used
RUBBER (CAOUTCHOUC) CALIBRATION CURVES
GENERAL CONSIDEHATIONS
The lubbeL hyclroc~rbon stau(ild is pllpa 1((1 by extracting the rubber from guayule bssue ac(ordll1g to tilt SPCI1((-Caldw(llmethocl (5) 01 by the Holll1lH-HaasiH modification of this method (p 2) The air-dry extraeted ltlbber is dried furtlllr in It vacuum OYCl1 with 30 inches of yaCH1Il11 at 63 0 C for 4 hOlIlH Till rubhlI sbindanl is preshyserved h1 It clos(cl contaim1 sto1(d in It r(fligellltol BCfole th( samples nrc weighe(l out the unopened cOIlbdn(l with the rubber i~ brought again to room tllllpelutnre
Two stock solutions each in triplicate from separately extractml standard rubber satnples nre prepared-the first sct of (-111(( containshying 01 percent 01 1 mg of luhbC1 ])(1 lniHilit(l and the other 02 pershycent 012 mg of rubber pel miJlilit(l TIl( (I(~il(d w(ight of rubb(L contiiinec1 in It known VOlIl11e of th(~ solycntis withdrawn Irom Il
burette or pipetted and made up to 25 m1 the standard volume used throughout the procedu]e
The rubbcr samples (01 and 02 gn1) for the stock solutions are weiOhecl out to an aCClllal) of o~ mg on nn analyti(~al balance The rubber is best mnnipulated by mNlI1S of t1l( stJai~ht hlunt-edged top of It cork knife With a little prnctie( OIl( (an leltlily sepnrate t)w desired portions by pLeSSIl1C from aboye Further subdivision Is mndt on a stout PVllX at(h glnssnt lla~t 2 mill in thlkne~s By pressun f10111 above and sheuling aetlOl1 Ye1~ small pnrbcllH can be separntetl so that the requit((1 11l110unts (un 1)( w(igh((l Ollt accurately The rubber sample is then divided into sl11a11 piC(es on the special watch glass by meanH 01 II coll Imife
One mil1ilit(gtl of lt1i isobutyl ketone 13 js placed in It special 30-m1 trituration beaker (fig ~B) and the fine1y diyilt1ec1lubber sample (01 or 02 gll1) is udd(d and heated on a hot plate under n ventilated hood to Il tempelature jllst under th( boilin~ point of the olvent A special glass rod il used t () t rit II ate the sumple (fig 2 11)
When the rubl)(r hll d issohed so as to makl a hOll1og(J1lOUS geUike 111I1SS hot methyl isohutyl ketone or an oI the other luhb(L solvents recommended (t aIJI( 1) is add(d and niicd with the rubber soltItion
31 Diisoblltyl ketoul WIlS not aailab1p (Juring ValtimC l1Cthyl isolJutylletonC 1II1ly be substitnClt1 11111 it is not a~ Cf1kiCni In Illis olllntion If the IllttC1 is used It is b(SI to pl Ilw fimlr diillPll Iubhpl palll(s slan( oPIuight in Ih( solvCnt lind 10 (OPl til (onlalll1 to IllinilllizC elIpornt(111 of sohPIII bpfolp wa( Is nppliecl to completp nlutioll
bull
bull
bull
bull
bull
bull
RAPID PHOTOMElRIC DElERMINAlIOX OF RUBBER AND RESINS 11
The mixture is tllll1sterled to It 100-ml yolumetlic flask with sevtlul washings of hot solvent cooled to n s(uHluld telllpelatUle and madtmiddot up to volume with the saIne solwlli SlwtiaJ IHl(uutioll mllst be takell in transferring t)( lubbCl solutioll to till YolulIHtrie flask so thnt llO rubber is lost It is cOllytllielit to illSllt It j-ill(h funnel in the ne(k of th(~ voiumptic flask to pOll tll( lubb(ll solut ion ill OIl( OLWlHtion into the tube of tht IUlll1ll with Ihl aid of tIl( glllss Iod nlld 10 follow illlshyl1eilintely with S(gtllnl ~Ynshings of hot S() I(111 whkh lIl lilst pouled 1nto tIll btll PI 1I(ld dIIleUy OW) till 1unn1 aId IhpII t1I1uugh Ill( funnel
H time hi not all objllt it is uls() flasible 10 p1alt Ihp linely diided particles of Iubblt ill tl( flask toJ1tuining Ihl sohPIlI 11(1 allo it 10 stand until til( 1lIbbpI is dissolYld TIl( llIblJll ioluliol)s alp slolpd in Ihe tightly s(ojlP(1(d OIUllwt lit f1nks in a ((lol dark placl Thel they willltIIlUlIl (OlUilallt ill Idut 101 an indlfinit( JlPIiod
Two ellliblHliol1 (IlP~ flIP IIltl(l(-OIl( 101 o~ gill of tisHlIP (ollin illshyhw 0] to 10 PII((Il of rubb(I ((1lt)middot1 to U mg of IlIbb(Iill tt ~)-1Il1 yo1ullll) and th(middot otlHl for ()~ gil) of tisslIp (ollaining 10 10 ~l() peLshycent of lublJPl (O to 10 Illg of lulllJpI ill a ~)-))Jl YOIlII1IP)
(Hns HlJ 111 TO 1 II~IWEX( (II BIIII1EH
III oldl) to ll(llllP (ITOI (0 II Iltinil1lIl1l a lIitahl( lllillobllllltp is lIs((lo Jl((lpn (P IhI ~lt of stal1da Id solut iOlls 0 f a Ii ng (OJllllllllll ious ill til(gt (III)(r( Ol 10 1 gt(I((lIt of LubbI In (11( PI(sPIII WOlk th( 1111shypIoypd HlhlHIg mic)obm(ltp Il bullJ) whkh lIi(IlJalpl dlli(I~ 10 0001 1111 was Toulld sntisiadOlY F(OIll n lll-pltIllllt -talHlulIlllbwl solushytion in HSlIitnbh solnnl lt[lIiIlIUJl1iiat( aliqll()l~or n) Ol o~ n and ()t 1111 al(lllla~UIpd (Jilt ut n stalldUld ~Olllli(lll tlIlIJl(1atulp (~) C ill wlitllmiddots labolulol) I IlIIHIl-of II lllillOillIl(tlt illio ~l-lld yohulI(lie f1nks ploid(d it h gla -(OPIllIS gllollgh of 11ll lubhpl sol Pili i~ thllI addltl to (tl(lt flask to IlIak(1 l 1111 Ill1I IUI(middotc (0 t hl all)ollllt of lllbOPI solutioll ]ll(yiously nd(lpdbullflll DI ntl 01 JlImiddototlmiddottli lolloid solu tillil Iras h(PIl Hddld lIP (bhpl is JlI((i pi III tpd IIlld SP(middot(t )opl)()tolllshyd(gt( 01 (jIOlilllltp) IPallil) an IllHdp 1I((OIdillg to 11ll JlI()(pduJ( Oil shylitwd Oil pagp 1middot1 Th( 1(ldillg~ 101 palmiddotll (OI1((III)Hlioll alp 1I(Iaglt1 anel plotttd Hgaillsl t( ntilligllIlll of 11))1 hI n ~)-1ll1 (jIIlIlH 0) [gt(lClntagl of nlbblI (nltuln(pt 011 tw bnis of tl2-glll lilsul Slllllp1(gts and aliqilOt olulllt IH(IOI 101 (itl ]1I(J((dlll( out lilll(1 Oil pagl 1middot1 This PI()((lhll( i ((l(alld t win ill (a(1 (11( II slandald llIbbllsolushytion was PI(gtllllpd IIOIlI slpa latll XllH(1 ld 1 a utln)(l lllbblI 1 III pips TlwcOlllpl(tpdtlla alp pol(l (1) (loldilla pap(laslrowl1 ill figulp I
Tbl )llO(p(II I ill lllilking a (Uln rOl I to ~ jiI((lIt of JlIlJh(1 i~ simi1t1I to (hat rOl 1Ill l1IlP ImI1 to 1 JllI(PIII (x((pl ill a f(middot dptnils The quinlu]lli(Htl aliqllols a 1( sput(d Ht (lI 12 a j 0 (78 n alld 10 mg ])(gt1 ~i-1Il1 Yolunl III sNuIing thp 01 Illg pll 2)-Jll1 YUlll))lt til( (gtIO(ltlIII( outlillPcl ill IIIl PIp(tding pnltlgllIph is followpd In the rllngl 1 toj Illg )IN ~)-1I11 OtIIl1I Ilw (lsi 1(lt1 (oJ)(tlllltlliollS of lubbpI alP s(gt(ul(gt(l h IlIPHsuljng alhplOi- with Xnlional BIII(atl of Stnndlld~ tltllsf(I pip(Ws flOIl) tltl OI-PlIl(1l1 lII))ll sol III ion
12 TECHNICAL BULLETIN 920 U S DEP1 OIr AGRICULTUHE
RUBBER IN 25-ML VOLUME(MGl
100 1~__middotOT5___ITO___15__2~O=--_bull 2r5_---= bull 3rO__~-_40 bull99
98 shy(I) CI Z
~ 97 ItJ II
~ 96a f-IIJ
e95 o l
94
93
92 ~__~__~__~____L-__~__-L__~L-__~__-L__~
o 1 2 3 4 5 6 7 8 9 10 RUBBER (PERCENT) bull
FIGURE 4-Cnllbrntioll curve for rubber in 02 gill of gt1n~ule tissue containing 01 to 10 p(rcpnt 0 lllbhlI (nlnllillg~ (Ill 1111 J~pl~ll llhooplf(middotttmiddotlc colorimeter with 720middotmu filter und amiddotml uperture the 01 divisions required in actual pracmiddot tice for photometric IclHlings arc olllittltd)
Similarly hl the range 5 to JO mg pel 25-ml Yolume the desired conshycentrations of rnbber urc measured from the O2-pllmiddotcellt solution The complete data lire plotted on semilogtllmiddotithmic pttpel as shown in figure 5 A
STANDARDlZATJON AGAINSL G1IA111 ETlIIU 11 ETHO()
1he alternate ploee(lule of stt121l1ald izing th~ IneHell~ method ngninst the Spellcc-Cald well method (II) altholl~h flaSI hIe 18 not adVIsable because of the extra work J(quiled ancl the introduction of the expershyimental error of the benzene extraction method
HESINS CALlBllATION CUIlVES
The procedure for constructing cal])lation eUlves for resins ttIlulysis is similar to thtni outlinlltl for lubb(l lxcept that resins exndate of gunyule is lIsed as the resins stundard The resinolls exudate disshysolves very readily in the resins solvents listed in table 1 It may be prepared in two ways for use as a stnndard-the clean exudate as bull gathcrcd from the plants is dried for 6110mB nt 65deg C nt a 30-inch ltcuum or the oXllllate is dissolved ill acetone and filtered In drying
bull
bull
bull
RAPID PHOfOMElRIC DJllImlMINAlION OF RUB BEn AND HESINS 13
RUBBER IN 25-MLVOLUME(MG) 2 3 4 5 6 7 8 9 10
r~
eo en ()
90
f--70z Q ~ 60ltl LIJ a ~ a LIJ 40 E 0
0 50
~ 0 ~ I 30 0 ~
A 20 I I
o 25 50 75 100 125 150 175 200 225 250 RU88ER(PERCENT)
RESINS IN 25-MLVOLLIME (MG) 2 3 4 5 6 7 8 9 10
1--90
80
en () 70
I z Q 60ltl LIJ a
50 0
a ~ LIJ 40 E 0 0 ~ I 30 0
B ~I20 o 25 50 75 100 125 150 175 200 225 250
RESINS (PERCENT)
lJIGunE u-Cnlibrutioll cUve for (il) rubhcr in 02 gill of gllnn11c tisme conshytainingl to 2G perc(lt of 11IUU(Il I1na (1]) rpSillS in 02 gill of glI1~l1ll~ tissue (ontnining l to 20 nelecnt oC l(sin8 (U(ndings Oil 1111 E(lI~1I llhotollectlit colorlmeter with 720-mtL filtcr and O-ntJ aperture the lO divisions llquired In uctnul prllctlce for pitotoulPtlie PllllillgS tlre omitted)
in vncuo arelntivply HllHlll qUllntity of (xutlnte is plllcel] in a lalge dish since the mass rOHmS nt the beginning of the drying process Pracshytically ull of the ne(tone is evnpollltpd olf oyer a steam Ol WItter bath and the residue is dli((l pnlYllized in It mortnr and preserved by
14 lECHNLCAL BULLErrN H20 U S DEPl OF AGRICULTURE
drying as indicated for fresh exudate In all ClSeS the products are stored in airtight containers in a dark coul place
The usualllnge of resins from gunyule tissue is about 2 to S percent on a dry-weight basis For work with this plaut therefore on1~ one curve is needed A typiCallesins ealibrntion CUlTe is shown in figure 5B
PnocEDuuE J~OH RUBBER ANALYSIS
Duplicate lXiLllCtiOllS arc made for each tissue analyzed and duplishycate photometric readings are made for each cxtmctioll the final value therefore reportcdreprescnt- nn avcragc based on the four phoshytometric readings
Thoroughly mixed O2-gm samples of the finely ground tissue are weighcd for analysis on the basis of l11oistUlc-frec tissllc The samples arc weighed to an accuracy of 02 mg Oil an analytical balance The method of deriying factors for making eOllections for moisture in samples has been thtailed on page
The weighed samples arc trallsien(c1 to the 2-m1 volumetlic flasks with the aid of l-inch glass funnels and 20 m1 of methyl isobutyl ketone is added to each flask The contents in the Hasks are heated m a constant-temperature oil bath at 115 0 C for 30 minutes uncleI a yentilated hood rhe flasks are removed and any adhering oil on the outside is wiped off with Kleenex 01 H similal cellulose tissue the C011shytents of the flasks am cooled to a standard tempellltule (25 0 in the writers laboratory) in a constant-tempelutllre ater bath provided with a motor stirrer if available and made up to volume with the solvent After the contents are mixed the flasks are allowed to stand for a few minutes until most of the insoluble residue settlcs to the botshytom The extracts are then carefully poured into JO-m1 heavy-duty centrifuge ulJls so as to include as little as possible of the settled insolushyble residue The centrifuge tubes are stoppered with cork stoppers and the liquid is clalifiecl by centrifuging for 10 minutes at 2000 revoshylutions pCI minute The clarified lIquid is poured into 25-m1 volushyl1Ietric flasks plOicled with ground stoppers It i impoJtant to pour off the clalificd (dlart in lWIt a lUlllie that the ill8ol11ble cNi(hwis not Sti1((Z1tp A 1-in(h funllel is plncCd in the neck of the volumetric flask A filter stick (fig 2 D) is inserted in the centrifuge tube through he liquid so that tlH enlnlged palt of the gtiek seals off the insoluble residue and a small portion of the exmet in the cone point 1Vith the index finger the stem of the filtel stick is thell held against the side of the tube towllnl the analyst who holds the tube with the thulllb rmtl t11illt1 fingCl The txtlHct is thell poured off easily into the yohunetlic flask without distnrbing the insoluble residne The COllshytents of the Hasks are then ))ollght to the standard tel11pelatme in the constant-tempentl111e wnter hath
The reagent blank us(d wit h the spectropllOtoll1lter 01 (olorimeter ig prepared as follogtvs ) 1111 of methyl isobutyl ketone 01 other solvent used is pipetted into It 25-m1 yolumetric fiask and 01 ml of protective colloid solution for rubber is added the mixtule is made IIp to olume with acidified Oil-pelcent ethnnol and mixed again the rcquired vo]shylime of the mixture is poured into a cuy(tte or an absorption test tube
From each plir of tissue extractions to 5-1lll aliquots 01 the clarishyfied extlact at the stnndanl tempCraLule ale pipcUed into 2ii-m1 volushy
bull
bull
bull
bull
bull
bull
RAPID P1IOTOMElRIC DETERMINATION Ol~ RUBBEH AND RESINS 15
metric flasks and 01 m1 of protective colloid solution for rubber is added to each One additional5-mL aliquot from each pair of extracshytions is similarly prepared to serve as a key to the standing times for the final readings as indicated in table 2 These additional aliquots are first made up to volume with the precipitant acidified Do-percent ethanol mixed by carefully inverting the flask three or four times] and allowed to stand for 4-minute periods before the reading is made on the colorimeter Vith these preliminary rendings a~ a basis the standing times for final readings are taken from table 2 For example if the colorimeter reading in rubber analysis at 4 minutes is 655 then the standing time is 15 minutes
The two rell1Lining duplicate aliquots for eath extraction are then made up to volume with acidified D5-percent ethanol mixed by careshyfuIly inverting the flask three or four times nnd allowed to stand for the required number of minutes as established by the preliminary 4-minute trial readings (table 2) before the final colorimeter readings are made on the contents of the flasks
TADLE 2-St(llllliIlU time for variolls (OllccntratioIlS Of rubbcr or rcsins aftcl iJleaipitation bcforc colorimetric readings mc macle
[5middotml aliquots of rubber in methyl isobutyl ketone or of rcsill~ in ncetonylncetonemiddotcellosol e 3middoti both made up to a 25middotml volume with pr~cipitantj readings on lvolyn photoGlectric colorimeter with i20middotml (690to iiOmiddotD11) filter and Umiddotml aperture]
RUDDER I
Range of colorimeter Approxima(e S~nuling i Rnnge of colorimeter Approximn(e Standingtrial readings after 4middot range in conmiddot tJIIIG for trini r(adings nfter 4 range in con tifillnlOalcor minute stunding time tcnt In tiSSU(l Unnl I t I t (rending IIlIDU C stum Illg lOW _ tent III Issue reading
Percent Villlits II Perfe~lt Jfinul 955-999 bullbullbull bullbullbullbull 09-01 00 01-03S bullbull ~ _bullbullbullbull_ Jl-O9 10 743-954 bullbullbull ~ bullbullbullbull __ _ 43-10 30 1420-550 bull ~ ~ 137-94 5 6_3_9-_74_2__bullbull_ bullbull bullbullbullbullbullbullbull_-_---- 6__8-_4_4---___ bull ~ ~ bullbull ____ MQrcthan 13ibullbull_-~_ _ ____ 15_~elow t~ 2
RESINS -----------------------------~--------
957-999bullbullbullbull ~ 139-01 60 11419-amp11bullbullbull _bullbullbullbullbull ~~ 13~5-939 10729-956bullbullbullbullbull_ Ii 25-1 middotJO 30 ~gtl2-40(L bullbullbullbullbullbullbullbullbullbullbullbullbull _ 2025-1320 5 595-728~~~ bullbullbullbull 8 as-G 20 20 IBelow 292 bullbullbullbullbullbullbullbull- More thun542-591 _bull ~ bullbullbull_bullbull_bullbullbull 038-039 15 2025 3
I Precipitated with O5middotplrccnt HSO in 05middotpercent ethanol When the npproxilllull concentrntion of rubber or rcsins in solution is not known trinl colorimeter rend
ings atmiddotJ minutes s(nnding till nrc mndelS n guide to the required finnl standing time indicated in the last column III prncticc UII cxtrn nliquot is prcpnred for precipitation and thIs is discarded after the trial reading is mnde
3 lrccipitnicd with OmiddotpcrccntlhSO ill HO
PnOCEDunE I-On UESIliS ANALYSIS
The procedure fol resins unulysis is the same as that indicitted for lubber analysis eomiddot(I]lt that f he -olyent js acetonylacetone-cellosolve ~)-7 tht precipitant js O5-perctnt H~SOI in H 2 0 and 01 1111 of the protective colloid solution for nsins is added to each 25-m1 flask conshytaining the aljquot of the extract before the precipitant is added
PnOlmmlHlC INSlHu~mNTs UECoIUlENDED AND CALCl]IAlION
OF UESurlS
Photometric readings of percentage of light transmittance (T) ale made on the Coltnum double monochromator spectrophotometer at
16 lECHNICAL BULLElIN 920) U S DEPT OF AGHICULlUHE
750-111 wave length or renclings n1( mnde on a colorimeter pLoic1eri with the monochromatic filter eOIl)Il1l1tioJl for sllecting the npploxishymate wfLYe ]cngth at 750 1Il~ For routine deterlllinations the Evelyn photoelectric colorinwt(r ployided with aTW-lllJ filteL is IC(0l1111HIHtll
The liquid in hich the preeipitnted lubber uld rcins are susshypended is pOll(d very cHrdully down the ill~idl of th( clette o absorption tube to lLYoilllllC fOLll1ntioll of ail bllbblls Aft( LUbbet find resins preeipitation wlwn the EnLynpho(otkcllie (olo1imetll is used the readings are nmde nft(L thl standing tillll- hOWll in table~ It has been foulld (OIlllliellt to 11lPtipilatl tublwr 01 llsiIlS from the aliquo(s at ~-millute illtlLvals This allows stlilieipnt tillle to check the eOlolimet(r and to makc 111( lNHlings Vlwll a ehangp is IlltHk fLom onc rending 10 the l1lxt it is advisablp 10 llle the clIvctte 01 absorption tube nt lpast twkp with slllall p(Iltion- of the llllltiol to be leitd
After the colorimd(L lluding lta e becll Iltndp till IlIl II igllIlllS of lubbel or resins or thc lpL(el1hlges pnslnt in Ihe aliqllot are r(u1 from cal ibmti(Hl (urVlS (fig~ 4 and raquo or from plepn Led tables of eqllivallBts baecl ill each (liSP on (x[lerimPlltnl data The results are expressed as percentages of dry weight (S hours drying nt 100deg 0) of the original tissue The errol lltle to lCflyjng the insoluble residtH in tbe voltlllletLie pxtLHclioll flflsk wlwn the pxtrnetis being mnde up to YOlllmC is V(ly slight sinlte only (U gm of tissue is used FOLroutine allalyscs lhis ery slight eLlor mny be dislpgnltec1
EXPERIMENTAL RESULTS
The experilllCnlal reslllts Oil hi(lthp method- of tU)lPI and l(sins analysis a le based ttl( d icussld blicfly hlrehl
PHEPMINrlON OF SAlULES
No difliclllty was expPtitI1(ed in pltparing slmplls of llllrscly-glOrt guayule plants 1pss thnn ~ YPH1S old 101 rllbbpl alld IPSills analysis In the cnl of Odll filld-gl()n gllayull plants PIIOtS hopel mtty be introdmp(l by the custOlllalY Jlwrhod 01 pICpalillg Ihp sampl(s 101
HlutlYHis as is lwipfly i n( ita ttd ill th is s((tion Smh enOlS do llot nffCct the ])lCcisioll O[ t1H llwt hotls for LllbbtL n nd Il~in~ nnn I sis i nee till) are due solely to tIl( tbsup--ampling (llo(pdule in thi (a~e of oldeL field-grown plall TIll 1lllt1lOcl of salllplill7 fipld-gl()l1 plants JllOLC than ~ Y(HrS old thenfort Ieqlliles iurtlHl jnttigntioll
lgtAHnOILr~G FOR HEllOVAL OF UUVLgtS
Parboiling which (onisls in boiling gllltyule plants in water [OJ
8 to 1~ ~ninll(s ~s col1llllonl) uSNl a~ n llHans of Itlli rCnl()y~l prior to drymg nnd gllnllng It I~ tHI([())P ll(e~Sllr to ltItLeLnunc all possiblt~ eflct oi tlti PLOtPlllll( )ll (Il( final results Exp(liments have sh(nm that (helt i- fl Flight loss ill til tmiddotjght of lOO(S and 4(ll1S In I typi(ul lXpelillltll hlu1llHs of ~- ii) -1-ytII-old gllllll( pllllb were Italnd at randolll Olll ( of talns wa- paLllOil((1 and the le~es (1( haIHI-pi(kpd [lom till o( hpJ Ht Both pis (1( dlipd for 48 hOttlS at (i) C in a llI((lwlli(al (011((( ion Oyell Th( lpsult are SUI11111I11izNI itS follows
bull
bull
bull
bull
bull
bull
RAPID PHOTOMETRIC DETERMI~ATIO~ OF IfCBBER A~D HESI~S 17
Dry ucilht lust ill lariOilillf
Plaut (pcrcrllO 1 1 -I2 ___________________ _
213 _____bull _____ bull __ _______ ___ ____________ 12 2(
pound(111_ ______________ 1 R
4_______________ _______________ __ _____
A __ bull __ -_
The efred of parboiling on till final lllalp i SUllllllatmiddoti7(middotd ill figmc G Rubb(1 lecoYelY w(t about 1 percent higher for parigtoillltl plants and lEsills re(ovelY somewhat o-er 1 i)(lr(lllt 10Wlr The (Ii tference in lublH-l r((o-elY cannot be ae(01111tltlt1 fot by loss in dry weight _ due is to be found in a study of thE grinding lwhadol of a parboiled and an unpnrboilEcl shrub The grinding of the patboiled shlub in the hnml111 mill is much fadlitated and ns a rule for tissue with a rubber contCnt below 10 peteent llO aggregates of rubber deelop in the 1Il11ehinr during the (Jpelatioll Yitll the unpnrboilNl shrub some dillictdty may 1)( (lxppliellrl(l Sill(( sOllle of till sti(ky ltxlldutl Oil the plant may scI( u nlldei for the fmllHltioll of lublH1 ngglPgates Til is apparently explnins the npparlllt los in ruhbpl frol1l the llnpariJoiled hrllb as eompnlelt1 with thl palboilld (fig (i) TI1(loss in r(sins
II
RUBBER
10 f-
Ishyz LIJ 0 0 LIJ 0
9 --RUBBER -shy-------shy
-- RES INS -shy---shy-----_
IJ) 8 I--Z IJ)
LIJ 0
0 7 f- RES I NS -0 -shy0 LIJ III III J 6 f shy0
LEAVES REMOVED BY PAFltBOILING
5 f shy -shy - BY HAND PICKING
4 I I I 35 30 25 20
SCREENS (SIZE OF OPENINGS IN MM)
FIGlRE Ii EtIe(t IIf pnlticlp sizE Oil lEcorPQ- of rubber lind (iiil1s when lEgttiye wEre remond hr Pl1liloiling lind h~ hand pi(king ((Dlltrol) plllllt1lt groUlld in t hammer mill
6114038-46-3
18 TECHNICAL BULLETIN 920 U S DEPT OF AGRICULTURE
recowry from pUboil(d shrub may be due to the loss of the resinous exnc1ate during parboiling This exudate forms ns It SClim on top of tlw )iquol in the tank
On the basis of t1wse results the recommendation is made not to yaly the nwthoC of leaf lemoYal in any 011( lNi(lu(h project Then fltirly compalabh IcmLts should he obUiined
70 ~------------------------------------------~ LEAVES REMOVED
BY PAR80lLING ____ BY HAND PICKING
60
-I-Z 1amp1 0 50 a 1amp1 a
en 1amp1 gt1amp1
40en gt-CD Q 1amp1 Z
I shy 1amp1 30 a l shyx C)
1amp1 ~ J 20 I shy 0 I shy
10
O+--L__L-~__L-~~--~~~~~ o 10 20 40 60 80 100
NATIONAL BUREAU OF STANDARDS SIEVES (MESH)
FlGntE T-lJiMlil)utiun of l1Ultkh si~(s of gnll~II( tiSSU( JrIOllll(l in a Ball amp 1ew(1 mill to pass six dllIerNlt S(I(euroII 1(IlYes Iemoved from plants by palmiddot boiling 11(1 hand picking ((olltloll dpfo1iatld plants dried to 1I lUoistufl l0I1t~nt (If 01 to o) 1)(ICl1It ground tiSSlli IbalH1 1() minutes ill II ~i$hel
bull
bull
bull Kahn shuk(f
RAPID PROTOMETRIC DETER~UXATIOX OF RrBBER AXD RESIX-i 19
GHl~DIgtiG
bull Th~ entire pant 01 plant l)iHt a~(gt fl r(ll it pllllIIirU1ry lSillg fur J hours ntGi~ C prIOr tD t 1( plChmll1atmiddot rLlmhll III a II lItmiddot or n Ball amp Jewell mill ~n llltllysis of paldch lzP- nftl~l (oar-( IIindill shows that tlwy ar( about tIlt llllH fOl parbojlP(t awl IJllllluhoileu hrubs I fir 7)
The coalilly gloUllll ample i-- thPll Ildlll forI toUtmiddot at ni C afnr which it ha lllilobtllL(gt output of ~ llllut lII hmiddot- dptPlIIlilwltl by drying submlllpil- at 1110 fot hOtll- TIll 1 IIIIll i lltllt lmiddot0l111d hi a IluninHl mill TIll mo(lel uP(t in thi IIIk i 1I Hu IIIOilll mill as IllUllifill bv Hoss nnt Hartlet ( 1 -[1lt111- with n1ll1l1 pldushyrations ittI lilnbhell b rill HanlIolll V0ll11nHiol1 ElIillllmiddotrill (0 The size lutllihl11 iUlJnole So I ( 111m t ~ II t HUIII Xl) ~ I L~ 111m nnd So 4 lillllU1 11 ttllilhmiddotj 0 r tllP Imiddotlult~ p(lln-It willI t11(e Sll((IIiZtS with )arl)Oiltll awl uil)Jtllboiltd hrlll b lOwl1 in fif1l1fmiddot-- This hows t tnt 1middottttIl ~(I 1 llllll (Up jlllilnl IHlt that
r------~-------r--- ~ --r IHAMMER-MILL SCREEN
O~ NO1
NO2 ---shy U NO 3 ---II
I
bull lL
z
r ------ l 30 ~ gt III
i I Imiddot
i ~ I
I 1 I I
~ 20 I - 1 iii 1[ r 10 ~ ~ ~ I _ ~ I r A bullbull
o bull L-~__~__~~__- ~~ 20 40 60 80 100 40 60 80 100 200
NATIONAL BUREAU OF STANDARDS SIEVES (MESH 1
Yutln I i-tlillltiuli Hf pur id lZt f ~naY1l1 t middotnt r1 lI1 i ~ a hatlltlllI 1IIi11 to 1111 Lx IHtllllH middotIn Lt-anmiddot tIlllunl loy la1 litkh~ omrl t 1) tHul parbuih~ -t B ~ thmiddotfuliufptl ]~lahr thpt tu tt fit t 1 It+gtr-tt1 Jnui~tHn eunttlIt _~rnlitl tl~UP ltakmiddot~~ 10 UddU it~ 1 rtmiddot4~pt~middotK1~r ttakt-middot
bull So 1 gingt- 11 tt-liuin-Iy ltr~pl [lPlItl1tat of iilll 11animiddotImiddot- Eqltrimiddot tIlllll hnnmiddot llOWIl dutr fll llltldllllUU xtlutioH 11pound lnhbll lIl lP-ill frolll IolUlIl ~tlaYlllt tl-IlP by dlt IJwtmiddotlUlmiddot lItlilwd oil Ill 14 - 01
i-mllt 11111- -lwltld hi INd I li~ Ii I TIll lllhtIlttj of Itiu~ So 1 (lltll j thnt 11middotmiddot01middot lttwmiddot to amplil tltt Iollllli tilt art lpdnn ib
IntIIll ll~ i po--ihJI with tI lLllit Ilfltl[lll1t It honld l Plllplw izmiddotl rImt ilt tht h of -allllhmiddot with l lllblPl
~ontlnt of ill PPltllt til lIilll it i tlllt pll--ihl 10 11-middot t(1i Xli L
20 TECHNICAL BULLETIN 920 U S DEPT OF AGRICULlURE
Even with screcn No 2 difficult due to rnbbel tlcrltreCtlltiollS may be ob tl
encountered In thes~ caHeH it iH lWit to parboil the shlub fOL leaf lemonll and finally to dry to about 1 to ~ P(l((llt of tnoiibl1(l pound01 b(~t results jn ~rindillp in tlH hanmHl mill
It iH aclvlsable to provic1l thc hammer mill with a ground wire Hillel the presence of static electric (harges 011 tll(middot partkhH will ealls( Home of these to atlhelc to the inside of tllP (olltailWr OJ lila eallsc OI1l( of till pULticl( to form ngg1(llatls EIIolin lalllpling fl01l1 fhis SOI1I(I mlly be (onsi(h1llbl(middot
A1I10l1g the Holnllts with high boiling point that lIlay Ill IlHld in rubber anal)Hs I1IP Illllhyl n-alllyl ketolle methyl ioblltvl kptOIH diisobutyl (tOIH blltyl tHptate llethyl amyl 1Ittail (middotthyl(middotlllmiddot gly(ol diethvl (middotther and n-bntyl (middotthel (labl( 1) TIHse al( also I(sin 01shy
middotent but th( 1(~illS n1( held ill olution by the rll1)bpl pl(l(ipitant tthanol wll(1 lllbb(r is 1)J(lipitatNI (S(ll tabl(s alldmiddotl) On tIle basishyof the lxpHilllPlltH tll( btsf nil-round lolPlli -rol lS in 111( PIlHPllt method is lt1iisobutyl kPtonc wld(h was not IIltlllllfaltllllmiddotd ltIlling Vodd Yflr n A suitable Sl1lgtstit ute iH llHthyl jolllltyL htolt whi(h is l(porhd as llolltoxit UJ)
Clllos()IY(~ (ethykn( glYlol monopthyl (tIH1) blltyl earlgtitol (di(thyl(ll( gly(ol llIollobutyl (ti1(r)~ and acttonylacetOll( may be used as resins sohrCllts (table ] )
In the earlipr work with (sills analysis cpllosoly( alolle was selcmiddotet(d as a suitable solycnt Aitholllh (ell()~oh( alone is pxc(lllnt its rplllshytiwly gwatlL iscosity 1(I(b to bubbl( formation nft(I (SillS pr((ipi tatioll Thi- increased thp (xperimentnl (LTOI OIl of tltp othll I(sins solpnts tI((tollyla((tolH has the proppry of glpatly lNlulingshydH(OSity 11(11 altld(( 10 othr liquids This sohpnt tlHIeforl wa addp( to ((Uosoh( in slIflici(lJlt tlllIonnl to OPI(0111e the dinieulty On the basis (li~ex)le1inwllts ~ purts oi~ a(donyla((tOlll to I puts of (elloshysoh-f (bolll by olume) as Splldcmiddot(l Thp 01 hel Hoh(nl listed hutyl clLlbitol at l(llst the t((hnieal-g1lld( ploduct uSNl is appal(ntly not as good as eithe of t1w ot1(r two () a (ombinatioll of tlWSt
The SOlVllIts JOI liSt in tumlyzing artifkial lubbel$ hy tlw pr(senf method appllLently (lcllIHl on th(middot kind of llI))(I lIp-ityl (Jxidt is suitable Ol BUlla fi and hutyllthlI for butyllllbbl Tlwse reagents IlLe technical g1lld( Calboll amp CtllUil1t Ch(lllilai (OIP This Hllbjp(( hilS not bepn (XtpllHl(ly illwtigated by till WIit(I
PIIECIIIIJ-
All tlst fOl Ih( adlqlJalY or till IHllipitullb ll(Ollllllentillllll11Sl bl baset] on the plctisioll of tllP final I(snlts oiJtairwd with the methods The )redpittlllts s(1e((( n HpJ (xtcllsi( (xp(IimPlltatioll all HatiH~ factor (Hee fig Hi 111lt1 tabItmiddot (jH) Ext(IIin tllts llllTild Ollt hanmiddot shown that H Hatil-gtflltlOIy [gtIpeipitallt 101 1lIbblI is (li-p(IT(middotnt HzHO (c p reagent nil POll sp gl U-lmiddotJ) ill li-P(l(Put (tinmol by vohmlP liol (tllayul( Ipl-gtinl 1l)-P~ITImiddotllt H)~o ill Hl) by ollln( ii lL satishyfaeto7-y l)lp(ipitunt A solution of 1 palt of H~~o to 1 part of H~() (1-1) iI2So1 nnd abo yarious int(lIlIPdiat( proportions of tlllse suhshystanCPs giyp fait 1(511It8 but with till inlIptl(l ill [h(gt ratio of H~S01
~
bull
bull
bull
bull
bull
RAPID PHOTQlIEfRIC DETEMIlXATIOX OF HtBJER AXD RESIXS 21
to H 20 the )olutioll becollles somewhat vbcou5 and precautioll Il1Ult be taken to ttvoid bubble formation When it i5 poured into tilt Cllvettes
It should be lloted that both of these precipitants have an ftellleshymmiddottion It was found that when XHjOH was used in the rubber preshycipitant in pInt of H~~O~ the readings were -table l)Ut were not reshyproJutihk The lIl of XuOH in pInel of H 2SO j ran nHittble result as a llth H(HY(Pl WIWll til( li-P(l put lthatgtl in lublltl llnalysis or H~O illlP-ius anal)j wn-i uddint(1 thl eharalteliti(s of till liquid with pleeipitated ruhber or resiu in HI~P(ll-ioll n ren1 on the lpNmiddottroshyphotometel m tololinlPtprfollop(1 it lPgnlal lIlll II~ lxplaiHd on pHgP-I (Sl( figs 11 aIlIIl) Tid made it lloible to outain lEPJOshydlHibll tpnlt nntI (onplt1J1(Jttly till JpqnitPIl tlPgJPP of PJPcljoll
IIWIE(TI 1lt COl~101J)
Jtl thp ItJiPl middotxlwlillltnb hefoJ thtmiddot -1l]YIlIt allll pnmiddotdpitallb had lIptll ptoppJly adjutp(l it l fOllll tIuH till llP or a Ploltiw colloid -wll ltIi1)cJ [ttlJmiddotntl- imlIopl tll lmiddotpro]lIibility of the lPlllt JmUkllly ()Ilt 111 U lput lUlU illlihumiddot tOJllPOlUtl tpHd liglyeol teltlut( - llpanlItly IllmiddotlfP(] to lit til I1m t IHflll lImnnmiddott nftlr tlH filial prOIptlllll WtlP dlvPllill1 tlll 11lIlpfit (If thtmiddot [llltlltin lollohl wa Hot 0 natlv I1l(lhmiddotd III rlumiddot Ia- of tmiddot ill tllmiddottJmillaritlu it b [1 hmiddotjlmiddot til IIpoundgt Ir llH1 It liltr ill-llImiddottiT Ina lll ptlPII by it U( in ruhhfl mmly j 11If dtmiddottail fOJ tltt lllllmtlllll If thl plot pet in nlloid ~llntill tltlmiddotlImiddotmiddotlttlatiflll lIOlllllllhtiPI1 are iPllllll page
liTFHFEHliG COIOf
(hi II tht lllail 11111111111 that had til ill -111111 II urklll) om tlH method fot lublJtt tlIlO1 rpir- nlalv~i in plaut llllpll- wa ttl (lilll~ inare tIte (gt1[01 till to tIll ptP-PlHt f xi [aIWIIII- 111 TIlt amount of (olor varip from lUllIt tn -amp ]pplwHlI nlt rhmiddot lt IIf thE Hl(ltllial tllP part of till plllIt -lI11lhmiddot(l tilt hi-tlllY f tlll plaut mtteshyrial ~ub-lltInent to Itlllmiddotnmiddot-rill lliI 1011middotly OrllPI Inlw
In ruhlwr lrtl-i I Iii 1101 au Itmiddot 1Iplll11l by 111[ I--r ratmiddottilt thE -lllll]t with uptoIw or 1middotmiddotlIll-ol - wIdell [llllol- rlll loillriu nutttel autI thtmiddot lpill- Thi- howmiddotvt n(tnll- til lXtla -11gt1 ilt prlJ~edun) In lP-ill ltluay-i nllHufldy tlW[t j 11 1 1IO(PIlln fill the 11shylImya of hlulophyll Hwl rIlI-r middotIOII IHlttlmiddotJ dlH lUtl~ In plltIH withoUt alo aiftIriL till nmiddot ulttrll
111 pllIbIll1l Wi tilmiddotr hId h It-ImiddottHI tht Pltlpll 1 hlitlt lilt tlw tulllWlli tollImiddot uIwltllIIntut -lltUIhorlllllltll 1111 tIll tlettlllliIttwr IIf t 111 lWlrl-Uamiddot of bdt tl11blLlittUhmiddot r [1 tItmiddot preshyj
lipitatifll 1lJ llllllWI atbull 1iI- in III -1nrmiddottIi fHlttalldh nlrillU~ amount rf middotlorilig lIUlttll Iii lhll of ih lltmiddottllllhottohttt~l l~ol()r infrtl Hm II upd 1 rwmiddot tld~middottilmiddottll PlllItlhi~ f it j proYitiltl with tIll lilP--UlY tU(jlIdlllIlml tIltmiddotmiddot lllklllUIlI
EIECTIol OF 1 [EGTH~
-Ptfmiddott ral tracilull ru~lI gtIll fr 1 nllb t ~xtltd 1 lIlt-th vI iobmy1 ketommiddot lWtl rill [ Ixt lttltt ll UttollylaIiIitt1l11I1t~ ~-I itoiu YtHil)u~ typp of ~IHaylllt f i lItmiddot art hraquoil ill fio1ll1 ~l Th~ lp-nlt fill I11oohl uio[1t ttl willlr til tltN- fur rht IUiXtIUt iwliutll
100
22 TECHNICAL BULLErIN 920 U S DEP1
90 bull eo
I shyz 70LLI 0 a LLI a 60
LLI 0 50 z
a ENTIRE 2-MONTH-OLD PLANTS~ 40 b ROOTS AND BRANCHES OF ~ 3-TO 4-YEAR-OLD PLANTSen z WITH LEAVES REMOVED ex 30 a C CURRENT-SEASON GROWTH OF l- )-TO 4-YEAR-OLD PLANTS
20 WITH LEAVES REMOVED
d LEAVES FROM 3-TO 4-VEAR-OLD PLANTS
10 A
0
a Cd 100
b bull
10
80
I-Z 70LLI 0 a LLI 60a
LLI 0 50 z ex I shy 40 ~ en z ltI 30 a I shy
20
10 B
o~__~__~__~~--~--~--~--~----~--~--~ bull350 400 450 500 550 600 650 700 750 BOO 850
WAVE LENGTH lM~)
FJGcm O-Sll((middotlllll tramaniW1IHl (mrpS f(JI (xlmll 11011 n J1ll of jlta)nle tissur ill n 2--m1 Y011111P of (A) Illrthyl ji1I1J1ltsl krtonp 1111(1 (ll) nt(middottQnyla(umiddot tClIc-C(l1osuln a-i
bull
bull
bull
RAPID PHOTOlIElRIC DETEH-UXATroX OF ntBHEIl AXD HEstxs 23
ThE dula Pl(S(l1t(lltl indi(ntp Ihut 101 Illp ulimls llHthyl liohutyl htOlIl (lxtrHts (lI(I r(dolls of Il1Hxi11111III nigtol]gttioll wiH1I all (is-lIb 11 cOllsic1(]((l n1( blhn(11 wn ( ItIl( Its lIO to () I1It~ nlid Ii to Iii mJL
WhllNIS tlw I(gions of 1middottnL(s( light 1lnlllittamp al(l lgtPlW(PIl wan Ipllgtltsnr) to Ii nllt jW) 1I1JL nlld alio Silllill1l 111l1b (n SI(lIlId 101 nc(ton ]altmiddot(fmiddotollp-(llloolp ~ pxt Ill of 11a 1111 t illl TIl( (1101 du( to lolo ill tlw litlltitl a 1Il1 lullll(I tH lPill- hanmiddot bpllI PI(_ ipitated ma he 1((I1((d to fltI ynbhing poillt II ph( illg OJ illshylmiddotJall(( WIWp balld nhm ()) IIIJ1bullbull[1I111 lxjlPIitllll1b Illln -h()1 that Ih( lIIot uilahl( WHYI lHlIJ fOI 1-1 ill 1l11J1l(I HIH11Pill- illllllrsi i-in till IlPighl)()lllll()(l of ~llIl1lt bull
bull UIlIilHlIy of n typhn] lXPllillllllt to )10 l1iP(tiP ((JIlllo( of (ItOIS dul to lOIOl in 1llblnI Hnd Iill xtnumiddott 11(11 IIIIolp t jUl i p1llelll((l ill tub]lL Till llhlllt- 1tpIO]II Hnd ((llll~()h whit-h UI(I ](]Hllilltl n 1I01lllIhb1 01(111 lxt 11111 IIll 1llll)1 nmtp[in I and )(middotills Tid IIlnkl it poiblp nftlI tlIp uplll1tillll or tlll o1PIl( (0 [niH lip 1Iidl1p~ of lI111 11111(( ill lit ll11l1)[1 (llnlIb nlld Ihll
Sl(ll n ol1lliOI with tllP olnl IJllt illiollt HIl Iltlllll llllI (Ill ltllthpl prpipitnnt j Ihll1 nddld OUI ha a lIilPt lP( of till lIiciPlw of WH( lllIgth 7) lUI- ill llilllillatiu (nnl till tll Ixtll1I101l ()lll~
Tuu tmiddot-Elilll IJl flrldillY 11-1111 lrlllI IjfJI til islII 1 1(1 ([rllt IIIIIJIlIr JiIlIt~ if 1Il( Ihll 111111 k til I III Ilrln I 1Intd tf 11111 JiSf fill I I II I tIII Ilf Iilltl 1f1JlIIillII1f I Till 1[ 1 IId 1 (I (middotIt 11111 (I1I1iI1 1lf1IWtlfJlIIllfflr p middottrllhIJ11 II J III 7IImiddotIa 111 111 lilt jJIp 111 wilTII
t~t tnVIli~ ~nn r kn t~ i tmiddot ~~l Jr 1middotmt ltlTt
HmiddotOtt ~I~ lin t I ~ 1 t~~l ~qrmiddotthtmiddotrtwb
Hult-middottltlru t T Hw ullut rHtt~ r II I ~ PH~lllt
A~tmiddottHHjmiddott~rjd rl ~gtllh 1 tn~th~ ~ ~ middotI lt~ b w bull hmiddotth~ 1i~lIhun 1 Ii tnl Illd1 -11lt1(11i lullI lUI tJl ll~ t1~11n( I Ihan1li flfttIJir Ult I Uuhtltt ahuul l(hmiddottHmiddot~t trv r fti HIt lftbyl tlonhUt)1 k_hIl( 2 m~ fmiddotf tuhlHmiddotr In mlth~ llmiddotlf- 1 t r
t r_~ t j
Arhlitlltd ~llIIDHl NcWitn1 ( Ar-(lt()nc~middotttrrtrt ritJJI~ -Iu nllJtl4-middotr
ACtmiddottflnp fmiddotxtrn( ~ T-P511ftf tn mtmiddotth~ 1 ~difmiddotut~ kdn 2 nltt ulruhhtr in Un-tIl lltbu )J~IYt
rUth(Hl~hltlft HhubU
Illlh(I(t tttUtUt hUbtl til J ~jlitl(J Hilllll trtIIImiddotjtl1ll
(UShl I ~tlO wHllolH rulh r (middot1111$0]( J~rru t t )lthyl 15bullbull1middot1101 klll1l
Ili( UHUicbcul ~((i1rUtl ~ulu1iin 1middot lIUIll Ilti lrllltlllt I Ruhhr llt1thuI r1 -1 Irld
ltlt1111Sh 2 nuz f)rruhl~rm nlith~l tu- h f nt nil~middothgt(H] tlrlftmiddot 9lUtirtl middot1 1
rlcltfl( H(l dnllltml it
(IISllhH~rI( Iultruhtr CII05 1v ltTlft I 2 UI~r ublwr In llldh I hlt~1 11) lgtjdvr(llsl~9rlltmiddot middotlmin ~ I~ gt AIHItilltl no IrttipHallr iI
~ Bbnk 10ol m(thyl i~tmiddotut~i kdHn H 1 m1 j~~ l1rH-t lt~tlfltmiddotn sf n it ll HltlMjftr~nol O2~mlJ ~U~1o-ulp ti~tW -xtra~middotl(lt1 ltt 411 ml bull ie f Ct- kft rt t~ tirattJ middott ill r u l1kn ttJt
in metltl isobutyl kNqnf nn~i mljp ur tmiddotmiddot ~oml ~urr tttl i t w ltJj1JH kt 4t 3 nlank 1 mL((l1t~rthmiddot(middot mI mttr~ ~but a kmiddot tmiddotc d 11 ~ gtli~b~ hifIAft- fl~ lL lnti 149
ml8(dlfilll BO bull 02 gm guayule U$Stl(middot xUlClt-l tf(h tft wI n nmiddotmiddotmiddotlgt 1 lznt on tmiddot ~Jt r~1 ~~u~~ H~ iI~ thT
24 l$CHNlQAL BULLETlN l20l S DJltJPT OF AGHl(CLlOHJltJ
In table a is pl(sentc(l such c1il((t edlt1tIHC showing that thc (0101 Ixtrnetccl from guaYIIle tisslIe wit h II(P(OIl( n nd (pl1oso[yc is cll(div(ly sCIe(nec1 out by the s(lp(tion or wnw length )0 miL Oil t1w SI)((IOshyphotonwtpl This tnb]p all-HI ihos thai thl Juhlwl altl(l((1 (nn IJl quall shytitntivcly 1(I(()(Ipltl in tIlt PI(ilIH( or Ih (o]OIplnwPIials and Illsins and tlmt Iuhb(l WtlS nppnlllltly 1I0t (xtltI(((1 110111 11l glll1I1l lisslIt b~ tlHSP SOhlllts Thls( ((suIts ginmiddot (OliIHillg (idJt(( that t Iw IISI of waYl llngth i)ll 1Il) OIl till SppdTophot OIllltPI ii t hl 1101(1 p(oshy(ellule in photolllliTie IlIlalysis of luhhlI OJ l(sin-
SELEGTIO- OF )IOiOCUHO)IAIIC ItIIm ((1111110
On th( basis of th( IPHIlb shoWIl in tabl(l 1 al hlllpls (1( IIln(lp to SPCtl lC the PIO]Wl 11101lO(lIOl1ln til Ii ltlJ ((lIllIJi nIl ions 10 llIiOlS (oIOlimet(Is 111(gt 7W-Ill~ filtpl flllnhwd 101 til( I1~lI1l photoshyplpct1i( (o]oriJl1ltll fol which Ill( (hlll(IlIiitit~ oj t hl Ilda he light ilUIlBlIIhiSioll (t) elll nn -hO11 ill fig1lle 10 iws satlsfa(lolY IPshysultl 111( iiO-mL HitlI olllhintioll 101 whkh ttp (middotIatinmiddot light tlnnsmission (ullmiddotis a 1-0 showlI ill figllll (I is -nthdnlto1 hut this is not stnlHlnld NtllipmPlli
Up to fhl PlPHllt lIS(middotflll pound11((1 (ulllbinntions jn lltl iOO-I11L Iunge hayc nol bllll SlClIlld 101 lhp Klpt 1-1I1l1I11PISOIl (olOlinwtll bu fnltlwl nttCl1lpti 1( )(illg IlIHd
TJIpound OF ST~lmW AFTEH HIIJ1EII Oil HHSIS rlll~CIIITTI(J
~ considl1ltiol1 of ttp lillll of Inlllling af((1 plpeipital ion of 111gt)(1
01 l(sinSTlOIll ollltionis impoltant J(jl~ thC1HI(Plltngp of light IInIlSshy
11 rshy10 f shy
09 f shy ~750 Mil- DOMINANTI
~ 08 cshy I WAVE LENGTH z
I III III i O7 - I III
~06 - 05 shyw
a
Igti= 04 - 720 Mp DOMINANT ct WAVE LENGTH- ~ 03shy
02 f shy
01 t shy 1)O~~~gt~- J 600 700 800 900
WAVE LENGTH (Mp
bull
bull
bullFIGlRt IO- COJllPIUlItiw ~IW(middottltll tlnIlRlllii-lion (II (IllP( 101 1i11(1 olllhinulloll
with dominllnl Il(lllllgths at 720 and 7iO lUi
bull
bull
bull
HAPlD PHQTQlfE1IUC JjETER~lINATION OF Rnmrm AND HEtiINi 25
mitted (spertrophotoll1eleL lCuding-) Ol light (1 (tClcrl (phOlOshyJluol01l1et(L lcndillg~) i~ StlhjNl to (hangl
]fjt~l1le 11 and l~ show that ill til( (asc ot tJaugtIllitteltllight llJHC th~ (x[llliHlllIlnl (oIHlitiOllS tllpl j lilst n dtlln-e ill Pll~(lltngl or UllllslllittnlH( follrnY(l by It ptJiml of lClntin stability with only sliuht (1111 tHn- a f(Pl a lIt1ll1btJ of minutes The light t UIllllitblllll t l(1 ill(Iln~(s This lIIay IJP llllllJltlli7P(ll1 ffl II ow 1Ilt )( f(( darI oliIII tIIlIlNlIlitt(IIIlfJIIlh (iditilIiid Ilil1 pllIipintnl )uoshyIn Of ( 8inx in (~f1( I~iUII i~ Ild stahl I 11 itlll If 1inl nh prlshyilli(ioll of 11l1d(1 II IJIX f) jllIli II (fJJltfiIIlilty slllMI IIriot 1) IIIPldUnl1i tll(I1I rllltltilJl oj tJi~ Jlt jiot IUN ilUf Jxl1 will tIt( tOWI IItlllilil I 1llIlllblJIol I ill I~11l11111 d ill till ifjuids JjOI scnttplltl light 011 till phololltHJIOIl1lttl till dilPCt ion 01 elangl b tlw IPrfIi (If that illrli(atPll rOl tlulll1Jittp(lliuht It Itlll b( llluliJr I-(Pll that if l(middotndlnJ- IIIP mad n itl I t lIP ~()ll1d()lb lpalll this pllioJ of nmiddotlatirp tuigtility tllP llLot tIOllt thi Olll(P (nil bl IPdUCld to tIl lltini III 11 Ill TIll l~adiltg (illH~ bbll Oil tlHl datn rUl lublwls and llsinlt Illl ginll ill tnhh
50 r----------------------------------------------- f shyZ
~ 40 ~----~W~A~V~E~LE~N~G~T~H~7~5~0~M~P~~~~ ~ --------------------=-=-= ~ 30 f- WAVE LENGTH 540 M~ _z _____ ___ -=- __ _ ~ ------shyt ~_=---=-=--I GUAYULEIII 20 -Z HEVEA ltt II KOK-SAGHYZ f shy
4 6 8 10 12 14 (6 18 20 22 24 26 28 30 STANDING TIME (MINUTES)
FIlirtn 11 Emmiddot of wav hll~rh Il li~ltr tlall~lIIit1alHl aftI IUIlItHt -Imlli lug 111m for guaynh llmiddotn 011111 middotiolIlJh~z 1111111 llijlitul1 flolll 1lHlh~ll1Jllryl k11II11l ~(lilltlll h~ lwitlitll 111Inu1 111l~1It1 2)1111 o1U11111 (Helillins on (illllun tlunhll IlIIJlllw]ntllW111 lutl(I[lholtllllltlt with ijUjt Wlnl IHI Ilf1 I
11 EFFEGT OF Hbli 1 -()JXT10~
Tilt lnblwl ~()h(llh pxtnl( till IPillgt ubo It 1m nllu1- bellt -~atea thut ~lll 11-111- tUP olnbhmiddot ill middottIIlIlOl ~1It tlWIIJI( my U)t PIl (tlIHatcl WIth tl1l lullh(t I tahle lJ 1hln 1- -1111 tIll (llllstlOll of nny p()~iblt tITptt of XtIIl11 diflp]lws ill ((JlllPllttUliollS of 1l-in lil lolutioll alollJ with till 1lIltbpl TIU data ill wbh +ho on tIl( hn~is of (olorilllPill ladillU thaI tll( IIUOIl1t of lnbbll Plllipirntld 110111 Ilwthyl olnlld kptOlll olntioll IJ 1li-jHlllnt 1l)04 in 1-llltlIllt ethallol)- not amlll hy thl llllNlI(l of llvin aU1ouut of llins inolution bull
-----
26 rECHNICAL BULLEfiN 920 U S DEPl OF AGRICULlUHE
100
90
80(I) C)
z Ci 70 UI a 0 60 a ~ UI ~ 500 ~ 0 I Il 40
30
A 20
0
100
90
(I) 80 C)
z Ci 70 UI a 0
60a ~ UI E 0 50 ~ 0 I Il
4-0
30
B 20
0
--
--shy ---shy---
2 4 6 6 10 12 14 16
---shy= ~ ~ shy
-
2
025 05
10
15
20
25 -30
35 40
SO
-60
=70 80
16 20 2224 26 26 30
OS
- 10
IS
20
2S
30
35 40
-50
-60 -70 -80
bull MGPE 25-ML
VOLUME
bull
MGPER 25-ML VOLUME
Florm 12-EtTld (If till1l or Slllldill~ 011 light transmittallce (01 (A) gUllyulc lnUIl(I plccipitllitd frOIll llltt h~l isobutyl Ielollt solution Ily neidilic(l ethanul bull null (B) gUllyule ll~illii pre(ipitated flom aeltoll~lllcetOlll-Cl])osolY( 3-7 solushy11011 by H(illilip(i l1U (HPlldillg~ nt -lIlillult Ifllpluls 011 Evelyn photoelectric colorimellr with jU-lllp tlllll alit U-1I11 npN(lle spp also table 2)
bull
bull
RAPID PI-IOlOMEllUC DElEnMINAlION OF RUBBER AND RESINS 27
TADIbullbull ] 4-ReZation of amiddotmount of middottbber pleeipitate(Z Oln metltlIL isobutyl ketone 80lutions by OS-pereent H 2SO in 95-pere(lIIt ethanol to umollnt of resin8 udde(l U8 indivute(Z by colorimetrio readinU8
(Rubber ami resins cnlculntcd on bnsis of amounts in 5middotml ullquuts of extract from 02 gm of tissue in a 2fllll olumo( bull
Hubucl r~cocrell whcll rcsins nddcd as IndIcated Htbbor al1dcd (pllcollt) ---shy
__________bull_________ ~_12rpcrc~15011crccllt 7511crccnt IOOpcrcent
PerCtllt ercellt Percellt Percellt Percent o o o o o) 50 250 263 252 25000 500 500 500 500 700 750 750 751 749
1200 1250 1250 1250 1250
EXTRACTION TEMPEHATURE AND TIME
Typical experiments to detllmine the time required to secure maxishymum extmction of rubber und ltsills at 115deg U Ilre sUlIlmarized in figule 13 the solvents used-methyl isobutyl ketone for rubber anrl Ilcetonylacetone-cellosolve 3-7 for resins extraction-are very eflicicnt since under the conditions indicttted maximum values were secured after 30 minutes of ext1llction The most eflicient liquid for the bath (lig 1) used in extrtlcting rubber or resins is ~ high-grade cylinder oil (S A E ~O) The sand bath and such liquids as glycerol have proved unsatisfactory
RUBBER AND RESINS STANDARDS
According to the National BULeau of Standards 1-_ lhclc Is no gellcrnlly recoglllz(d standard lIIutcrlul [ior II rubber standard] The rubber hydroCllrbon ill llifferent samples of conmlcrciul smoked sheet or pale crepe from heclI pluntlltions nries from l~ 10 04 llercent of the totul nutletmiddot the most 11Ioruble conditions Of preparation
McPherson () has described a procedure for the pLeparation of pure heve~ (Hevea brasiliensis (H B K) MueH Arg) rubber from crude rubber or latex In the absence howevcr of ~ generally recogshyn12ed stalldard for rubber hydlQcllrbon [caoutchouc (CnHUs) xJ the standard adopted was that of the relnthely pure product secured from gunyule tissue txtractiotl nccording to the Spence-CaldweU method (5) or the motlified PIOCCdUlU of Hohnes lind Haasis (p 2) The details for constructing the calibration CULes are given on page 10 Standard rubber samples apparenl-]y can be stored for a long timc under the conditions des(libed on page 10 The duplicate colorimetric lendings for glULyule rubber newly extracted by the modified SpenceshyCaldwell method were ()J2 ench as compared with US) each for the sample extracted by the same method but stored 1 years In each case colorimeter rcadinllS were made on mixtures containing 2 mg of rubber in It 25-1111 Yolume
The selection of tt suitable standurd for guayule resins presents some dilliculties Tll(~ acetone extract of gUllyult estimated on (l gravishymetric busis~ for instance proved to be variable depending on the type of tissue sampled or season of sumpling because such fractions as
COllllllunlcntion dul(lt1 Octohtr 22 11H3
28 QECHNICAL BULLEQIN 920 U S DEPT OF AGRICTTIIlURE
16~==========================115 shy
14 bulli= 13 z ~ 12
ffi II Q
10 c w 9a w
8gto () 7w a
6a w
5en III ) 4 a
3
2
A 00 5 10 20 30 60 90
14~------------------------------------------- bull13
i= 12 z w II ()
a 10 w Q
9 c w 8 a w 7gt o () 6 w a 5 If)
z 4 If)
w 3 a
2
o+B~~__~__~____________~__________~ 5 10 20 30 60 90
HEATING TIME (111 NUTES)
lllGUltE 13-lDffect of time o( lICntillg O2-gm samples of gunynle tissue with solYlIt nt llfio C on lo(OVl)ry of lllhlJer alld 1Isim Lt HlIhblL extracted with methyl isohntyllwtone B resins Cxtll1cted with aCftonyla(etonc-cellosolve 3-7 bull
chlorophyll are weighed along with the resins in the acetone extruct but are not estimated by the present photometric method (fig 0) 1he use of a diffeJent stanclttrd waS therefore indicated
bull
bull
bull
RAPID PHOTOMETRIC DETERMINATION OF HUBBIm AND HESINS 29
The resins standard selected is based on n relatively pure source of resins the rcsinous exudnte 011 the stems of guuyule plants IJldimishynary expeliments with the resi nouS cxuclate from diffcrellt gllayu Ie strains of various ages indicatc nHlt there is little YaLiation in this subshystance on the basis of Colorimct(r readings 011 2-mg aliqllots of 01shypercent solution in It 2i-ml volume (tabl( li) Expelilll(lnts have shown that the air-dried (xuclate contains 3RtOH p(Ic(nt of -volatile matter This material is l(latiyt~ly stablp ill (OlllpoBition and is npshypurpntly on ly slight ly hygroBcopic as shoWIl ill Ia bl(1 1 Tlrp Ipsinolls exudate may be jJleplpd in two wayi-i fl liSP as a stallClHld-(l) the clpan exudate is clripd iol Ghouls at ()1deg C at W indlPs of a(lIum Hnd aftclbCinOglOund ill a molfalis 1)I(spI((I intn airtight COllilinel OL
(2) tllP Cx7lclate is clissolllt1 ill a(lhllll and filtplpd PlactieaJlyall of the acetm1l is thpn lYapolntwl olt OPI a stlam or atCt hath and Ow residue is dripd ground an(( PI(sPIld as ill tllp fin lllethocl Tlwse two prepalHtlolls a1( (ompalpd in ta hlp ) 111( (((tails fOl ~t()lil1g the resins standald and (onstlllcting the calibration CUITPS alc given Oil page ]2
lAIIIg fi-CUIIIllrsoi (lJ lIr-dr(1I IIIIi 1((11 II II-()I-tr((l l(sil~ 11111111(8 of I II 1111Ie
[Colorimetric rrndill~s 011 1~I11 phulll(Iclrie eolorillJct[lr with i~()middotmll (100- to iiOIIIIl) fillcr [lnd 5-1111 lIperture preeipitantl part ofO5middotPIrctllt 10 to 5 paris of IIOj
nupliclllc(oloritwt([
nIl(lin~s (hIlSlcAg~ ofSlmillXo JrNliltlCllt of fPsiJI$ L1Xtlrlntp on 2 IIIg ofplanls fllsins (XIHIIlt~Jwr 25-1111 vol
tII1(1) 1
leflTs Various _ bull ____ bullbullbullbull 3-9 Colll)Josiltrlairmiddotltlricfl bullbullbull nf)2 002
])0____ bullbullbull _bull __ _ bullbull ~-l Composilld (ri d at n5 C in aUmiddotimh lWUUllJ for l (jOuj(ja hours])0______ bullbullbull __ bull ___ bull 3-0 COJIlpositld disso]NI in neptolll f1l1erNl fl(lf()ll( GGO i(jO (Ivaporntld olT OV(1r Stpl1l11 halh TesidlH drl(ld I1t fi5deg ( ill anmiddotinch VIl(Unlll for 0 houlS bull
middot106 __ bullbull _ Jir~c1rild_~_~_ _~_ ~_~ _ ~ ____ _ __ _ OUu GOifina_~ ~ _ ~~_~ ___ _ _fln~ ~~ ~ ___ ~ __ 6(imiddotI tiliA H)[_ ltlu bullbull i18 tisSflOabullbullbullbull__ bullbullbullbullbullbullbullbull lt10bullbullbull _ tillO llitO406__ bullbull __ bullbull __ bull __ __ lt10_ Utl2 fon591_ fo__ bull liGa oOa 406bullbull _ __ lt10bullbullbull_ li5S OM
j Ph( vnluls in Uw Inst COIUIIlIl indieatp thnt gunyulp fesinous (IIHlnt( wlwtlwr dfircl hi Yn(tlLJ1l1 wilh L~ perc(nt loss of volntllt wutl pr or tWl c1rild giVPd npproxil1lnh1ly t Iw snllw colorinwtCr rNHiing- 011 till busis of aliquot~ cOlllniuiug 2 IJI~ of flsillS lXIHlntp l)tIf 25-mI volultl( Ihil- illdicate~ thl11 Uw UITW IJ1flS~ of olnshytile mntl(f prt~(iJlitnt(d gins npproxilllntlly Uw $1II1l (oiOfirnl1tlf ftudiTlJs ns tho ftsidtw A pnlill1jllaf~middot (XIlltrinllnt indicutls thlli th VUllltill muller l(lIlSists of thl Ilrplne oil fmcl ion I5-(1Il gtnplls or rlsitlOtlS (lxudntll gnvll by stPll1U distillation nn Uefllgl of 011111 of jl(lfPlIW oil with npproximHte tilllsity (If OHIi lind lhus rrprlsll1ll( IlPIJroximllt(I~ 01 Jerccllt Of t he original weight 1hls lllrClnlage complrcs wllh 38 llltrC(ntlost by drvinI( in IICllnllJ
aSplusmnUH perceilt or orlginlll weightlosl
The wailnble illfolJllntioll on tlH (ow-JitlPllts of the gunYllle r(~shyillOllS exudate alld tl1( HeetOlIP ext act of gaylp ti~slw is sllIllmarized in this paragraph lYalttI (u) alld also Hangcn-Slllit lind his coworkshyers 16 reported that 20 percent of the resinolls exudate from gUltyulc stems is parthenyl cinnamaie (CHuOH=CHC020 11JI2r) Steam disshy
15 (OIlIJIIIIUicatioll flom A T Haai(II~l11it llId (0011(11 Calif0111 ill Tnfiitnte of Tccllllology Past(IlIJI Jhps( wOlken al Htud~ing the COTlHlitlllllts of the acetone extract and other conlltituellis of guuyule
30 TECHNICAL BULLETIN 920 U S DEPT OF AGRICULTURE
tillation of similar resinous exudate in the writers laborntory has yielded approximately 4 percent of the whole as the telmiddotpene oir fracshytion Haagen-Smit and his eoorktrs nportec1 thttt about 25 percent of the acetone extract from guayule branches is parthenyl cinnamate and 6 percent of the bark (ltortpamp-phlotm) extraet is parthenyl cinshynamate These workers fm-thcI reported that 25 lwletnt of the nc(shytone extract frolll bLllllches is a compound with the tlI1pilicaL formula CBoH400a 1 percent is a compound llwltillg at 2P to 2T5deg C and 1 percent of the extract from the ]eav(s is tl (olllpoulld nwlting at 100
to 1710 1Valtei (6) reported that 3 to -l perc(nt of the tI(eton( txtract
of leaves and flowering StPIllS of guayulc eonsists of waxlike substances soluble in olgallic soln~nts but insoluble in at(l and (on(ent1llted H 2S04 The flactions mentioned on the basis of (onHLTutle esti shymates of amoullts actually isolated tlecoullted for about H ptIcent of the totalncetollt~ so]ubles extracttd from tll( guuYllle 11 rub The other constituents ltlilaill to be i(](ntifi(d
RUBBER AND RESINS CALIBHATION CVHES
Typical culibndioll Clllves iol Iuhbpl and I(sins bas(d 011 (ldtLminttshytions made nccoLdillg to the plocCdmC outlin(d 011 pages middotb to 1G arc shown in figulPS 5 and 1+ The spCdlopliotoll1lttL en (OIOIjlllctCI readings are plottCd on s(lIlilogalitllllliC pappi ag-ail1st (Il 11IbblI (011shy
100 ~ 90
80 ~ 70 ~
z 1amp1 0 II 1amp1 IL
1amp1 0 Z
60
50
40 ~ltI 30 ~ en z ~ ltI II ~ 20 C) ~ oJ
10 o 2 3 4 5 6 7 8 9 10
RU8BER IN 25-ML VOLUME (MG)
bull
bull
bull FI(lURE 14--Ctlihration curve fotmiddot gllftYlIlc lubb01 (Hct(lings Oil COIPIIHlII tlOl1hl(
monochromator SlCClrophotolllet(r with 7fiO-11IL Illtel alld Hllp Wll ( IHlll()
bull
bull
bull
RAPID PHOTOMETRIC DETE~MINATION OF RUBBER AND RESINS 3]
centrations From a casual inspection of these CUlTes it would appeltr that Beers law does not hold Actual tests indicitted that Beers law was applicable only within a narrow range in the upper portion of the curves The analyticlil results on the basis of photornetric readings nre therefore calculated by direct reference to calibration curves or from reference tables of equivalent values bllscd on the cnlibllltion curves
Calibration curves for kok-saghyz alld heyea lI11tulltl rubbers and Buna S (GR-S Chem Gum IV Goodyear) and butyl (GR-I Standshyard Oil Co Protoc) sYJlthetic rubbers are hOWllil1 figure 15 The samples of kok-saghyz rubber were furnished by the Diyision of Rubshy
100
90 ~I) ()
z 0
1amp1 a
~ a
80
70
60
s 1amp1 ~ ~ 0 ~ KOj-SAGHYZ 0 l Il
50
HEVEA~ ~
40
100
90
~ 0 80z Q 70a Co)
a 60 ~ 0 0 x 50Il
40 ~----~~----~------~------~------~--~ o 2 3 4 5
RUBBER IN 25-ML VOLUME(MG)
FmUIlE 15-CaJiblation curves fOl kok-snghyz h(YCII Bunn S lind butyl rubb~ls (Readings on gy((yn photoelectric colorimeter with i20-lIIp filtpl and 6-ml aperture)
32 TECHNICAl BUIJLETIN [)20) 1 S DEP1 OF AGrnCUIlfURE
Iwt Plant JIl(I~t ignlioll of thi BlII(un and (1( l))(parcd according to 11( SPltI1((-Culd (]] (6) PIO(((lllll Hlpt pal( CLPPe was (xtmch(L with acetone blI()Ieit W 1I(gt(11l a ttnlldal(l
SEXSlllVllY Ol~ llETJIonS
By lip pIO((l(II11P olltlillP(l 011 ]Hlg( +n Iowa (lOOl IIIg (11 1111i(l0shygmm (gHlllllla) of 1hblI ill a 2)1111 yoltll1ll (all )(gt dltpltld Oil tltl Col(man (lohlP mOIlWhlOl1lHlOl l-I)((t 101 l1lOt 0111 ci( I ill1ilnlly 001 mg of Iublwr ill a 2J-1ll1 n]ulllP Illay bl Ilad Oil till EnI)1I photoshyllectlie (O]oLillllt(I Thll ya lllll- 011 tilt IHl-i- (J I (xl ad iOI1 fmlll 02 gill of til-lI tH(JI(lillg to tllP -lllndal(l jll()(pdull 1(PIPStlIt IlO()2J tlnd 002) P(IT(lIt of llIbl1ll IPI)(((inly bull1t1lollgh -lI1t low allils can be d((d(middot(1 il lIoullt1 Ill IPtllizpd thnt till PIIOl ill PlI(Plltng( or tll( al110unt dltlIllIilll(J i ltlatlpl high ill tili PIY lo Itlllgl 111 aetllllllladie(middot Ill( lopl lillliL 111)(1(1 lIw (ollllil ions of tlil ]lI()(lltlIIIl u ol1tlinpd ipt at l11 11I1 or 1111gt11(1 illt i-1ll1 Ollllll IlPIPltPlltillg 01 p(gtl(pnt of JllUiJtL un tlll 1Hli or (xlla ion rlOI11 II rlll of tisSIll
EIlIlOH COSIIlIHIIO
In Oldpl to H(IIp ill )1lHtPltt pl((iioll illlpIi1I- it i lH((SSHI to slnlldHIdiz(i rigidly 111( Pl()((dlll( 0 illdi(ntpd Oil pnglt- - to J( If lids i dOlH tlip lXIHlinwnlal PIIll is t(middotdllld 10 n ndninlllill
Illlt pl(iioll of (hI ]lIPPllt 1IHllwd Oil til basi of ]llllP llIllJt1 alld Ipsinssollltions call hI jlldgl(J 110111 figllll Hi lileh lio- til HPIlIgl d(intioll oft -illgIP lI1lnSIlIlIIIlnt in lHi((lltagl of Ill( alllOllllt 01 Illhshy1)() 01 lpsins d((PI1I1 iJlld TIl( (1101 PlI(Plltaglt H1( gi (1 101 OJ) to
RUBBER IN 25-ML VOLUMEMG) 004 01 02 03 04
i= I I IZCtOW
fbA ICtU CtCt WW a
01 02 03 04 05 06 07 08 09 100 = RUBBER (PERCENT)
RUBBER IN 25-ML VOLUME (MG) 10 20 30
~ I CtZ
bBOw Ctu CtCt Ww o I~
010 50 100 150 200 250 RUBBER (PERCENT)
RESINS IN 25-ML VOLUME(MG) 10__ __3-0_ 40 50 60 70 60 90 100--_-- 2_-0
Ct~ -r- 1 I OZ
WCt UCt b C wCtW
a o I I 150 250
RESINS (PERCENT) o 10 50 100 200
bllI 1tI W-Yllnl dtd1 ioll I I 11l1 11IlI11 1(111(11 1 III Plll- IlIIIlol1 01 IIim~
bull
bull
bull solution Il basis J o golH of tiSSII (JlILCl-nt (11(11) for (~I) (l)1 til O 1I1
of luhllpl lin 1 III I (I Ill of lUhlJPl nllll laquo I J to 111 nlg of IlSlllgt (Itllillgs on ]iYllyu pllolwh-llrk CO[IJlilll(-(PI with nOHIP Iiltlr lIntl U-lIll allcrture)
RAPID PHOTOlJElRIC DELEHlllNAllON Cn HUBBER AND H1~SINS 33
10 mg of rubber anel1 to 10 mg of resins in a gJ-m1 yolumC For
bull
bull
bull
comparative ptuposes the leslllts arc also calculated on the basis oJvershycentage rubber OL tltsills in 02 gllI of tissul As WOlllL be expcet(d the error increases sOIlHgthlf for 1(lali nmiddotly low COlHell t1llf iOlls oj rllbbeL or resins The curves in figure 1(j s1l0 that ill til(gt Illlge Ol to 10 pCrshyeent of lubber the elTOI rangts Jroll1 abollt Ll to II) ]IlC(lIt abo(~ this mlllc tIlt (ITOl d(((ts(s to (ollsidlItbly ltmiddotss (han 1 1lICPllt of tlH mllollnt ltl((Lmill(d Hil1lilally in tlH (lISl of l(sins analysis (fig 10) the ltLTor is (onsit1eIubly INS than 1 PlLllnt ill (he lallgp of 11 t~) ~() penPII t
In nil ([lSl of lllhblI alld (sins lx(Inltpd tIOIl1 (issups Ol addcltl to tisslle lxtlads (s(( tabhmiddots (i H) illyolillg ll01P o(lllntiolls the eLI01
is hig]wl thun that indilHtld in figllll ((j Im pUIl Ill )])p I tllllllsins solutlOII
COlllUCIIOXFOH IXSOLl-IlLl~ Ilgsqgt(Jg
111 th( Jllo(pdulP ollllillPd 011 paw I till illsolllhll isSII Ipidll( tflpl (xttlw(ioll is (Ptill tlw lIask l(lll till xtlct i l1wdp up to yoltlllH It is not rOllPllipnt (0 IPt()PI qWlIltitati(Ir III(lw[olH a 11(1 pllooll extlnlfs of guuyull I is-lll alll thl1l main t11l111 up (0 YOIUllllmiddot bpCaUHI sllch all additiollal stltp wottld]) tillll-C(JllS11ll1illg Th( Iogiea nll(gtIshynntin is to mnkp tltl lXtlUCt Llld Ipsidup lip to OllillH in till original flask andi llPSStllY 10 llwlno tl OIIpdioll wlHIl (allIlnting [hc llshy
Hults f(JI [hl oll111lC displupd hy till ins()lllbh llsidll( III it l)picat (IXpednHllt (ollsisting of Jhp lppJiea(iolls if was Iollnd llftt at ~iiO ( 02 gill 01 Iuhhll pillS IPill-fl(( lisslI(gt (lollpdll fot llwistUlC ou basis of dlyillp ut lOW 101 ) llOlll-j (lbp(ld only t~ llllUll voiul11P of OOk7D~- OO(lOO(i Ill of lllthyl bolnl(yl 1lIOll( (lplhlli(al-t(Tnltle sp gl () Ii I ll(Hli (j at ~)) -gtitllP tl1(gt 1It101111( () r t is-lIl xt Iadld j sl1lall til( PlIOI dul to Ill(gt insoll1blp Ip~idll is slllall III [0111 ill( wOtk it (all lJp diIpgal(ll(l
]hcon~lIY OF HllIllgl AiO HESIS AIH)gl) TO EXTlIACI OP
GlYlLE TISSlg
Tnl)ll G L(IHpslntillp (ypi(nl llld(~ SllOS (hat all a plngl of HIOK PlI((nt ot lltl pltl( Ilhl)(l acldpd to tllP Itll h iolJut1 InmiddottcJllP xhnet
of guayulp tiSI1( WllS 1l((PllIl Tlli nllintioll flOlll (olllplpU I((OYshy
PIY i within flll pxp(IiIlHuttllIIOI ~illli]llly fnbll Ii llows thn 1111 llYlIUgl of 1O(1~ ])(I(Pllt of gllllYllII 1(-i1l- add(d to II( (pllosol( (xshytrae of IUllY]l t i~HI Is 1l(oPIPI
THl~ (~ Hf (Off Ill of 1111)( J OJ I~il~ lItfI(( In ~(JI1IJk~ Ilf (111 [lI1Il fI2 lIII
0 tlUfllllit i~~I1
Instrument
---- ----~---- bull shy 1(1
Colemun ruono~ltrOUlllt()r 2t) II sJl~ctroJlhOL()lIIeter with 2tJ I iflllllI wnclength Fetting 21 II nntl 0-1111 WU HI hUJl(L _ L U
Ill 7Evolyn photo~lcclrie (olor JU [ imctcr with iO-llIl filler IV (I
H1 0 t I I
llImiddot lUn WII 1011 HIO Wn mil lUulon
10 JIg1111 IUI ml lUl anh Io aLn 111)_I ) III li lU It 2) deg wn2SU DD
Irl JIll II IIr II US II
1110(1 lULa lUI IlK) IJ WU
I( llI Htl tNI 1(111 2tlNI HI 0 221) lllil t2S 0 1~ 10 1~13
In (I 2117 I
10U 1l(J ~ 4 _H_j ___
9middotJIlJ5 10115 10 00 lUU5 flUU 4li (tl03 9(11)
leIlKl 1l~)5 lOOU l1KIr JOIS un 003 OIl Ii
34 lECHNlCAL BULLErIN 920 U S DEPT OF AGRICULlURE
COMPARISON OF PHOTOMETRIC A1D MODJIoIED SPENCE-CALDWfLL METHODS OF RUBBER ANALYSIS
Guayule samples were analyzed by the photQ111etIic method and by bull the modified Spenc(gt-Cnldwell mcthod The values in table 7 represhyselltativ(I of typical results indieate It -atisfactory dcglpe of conformshyjty between the two methods in thl range of tiSSlHH with llHHC than OJ) percent of rubbtImiddot On the bnsis of the amounts determimd the results in this runge for the plmiddotts(nt lIlcthod ayernge apploxinHltely j percent highcr
~LAIII~ 7-(oIllJl(i~on of lltlllrIic (IIri mOtllinl SJl(II(r-(ulri-wall IIIrtlwrl~ of rlrrlIIillillfl 11)1)(1 COIIrll of UI(III
1 Flowers frllm amiddotmonth-oltl nursery plants
YAIIIATJO- OF SIli(LE DETEnt1NATIONS Fnoll TnEIIllIEAN
Rllbbel (Uall8i8-Thc plcCision of thc pLcsent method when gunyule tissues Hr( nnnlyz((1 for rubber may be j udg(d flom I Ill datil presentcd in table H TIl(se dahl -how that thl pplCPlltag( uriation of single determinatiom from nwan yullles with low standllrd enolS ranges from less than 1 to 4 p(gtrlent
R(8in~ wWlsi-r-s lndi(a((1 011 page ~j he INntlts s((uled hy the present phoolllttric nsins llHt hod are not tliltly (olllpalable with those of the grtLVimetri( ncetol1l-cxtlt1(tioll II1etho(l Thjs made it necesSllry to selc(t another lalibllltion staudud-tlll Ipsinous exullate from gullyule shrub-thut gies relatively COllstlllt photometric readshyings (table 5) The resin (olltents of guayule roots branchcs or leavcs usually ran(~e from about) to 1-1middot pelcellt The ple(ision of the present methotf WhCll gUHyule thslllS lIe analyzed for reins may be judged from the datalHmiddotpscllted ill table 9 1h(se data show that the p(lcelltage variatiun of sillgle lhmiddott(Lminntions iLO11 meun ynlnes with low standard NTOrs rangcs from about 05 to 4 percent
bull
bull
bull
bull
bull
RAPID PHOTOMETHIC DElEruIINAlION OJ RUBBEH AND HESINS 35
IAIILE 8-luriation inclieute rubller (mallSM of [1wIIle tissue bll thc 1111O0Illclc metwII
Vnrlntlon~Ilbher I (rom mean
ierCtnl Percelll ~OU -22 ~ 25 +27 ~ 20 +18 ~UO -22---------1_______ 51110 0G6 bullbullbullbullbullbull _bullbull
10 ro ----=ii41075 -01 1000 +11 1010 +13
rlln HI itil 1l9~ 1_ ___ =-~~~
115511 ~ US -111 III II 1575 -13 115 b tiS -I a 111 h WlU +22IIM-(middot bull 11K -1Ja Illi c 1000 +03 1J5H1 W +l)7 ll1imiddot tl 1575 -13
Mcnn 15951 131
1102-11 21fJ() +21l102-h _ ~~)SO -17 1102-c bullbull 21CO +21n02middotd ~OIiO -26
2 r~plusmn Il~ 21151 261 I -~-------bull---__ _~~_~______l-___--_
1 lhe$ 1111($ I1n (or SlIlIIllltS Stpnnltplr PHrilClld IIrtlrdlng 10 1hr prollIlIlr( OIiIIiIl(o(I on Imgt$ 4 to IC ~tcond nUlI1 hlr r(J)[ltnts stl1ndnnl llrrot of tilt 1I1(1111
1_1l1~ n-J(lri(iot in relli(Upound rpoundsins (lllalIsfs of VIOJII( lixsue b1 the lhomillric lII(lloli
-- ---~--- - __-------- shybull I I I I Varlgttton
_________~___ ~~lu_n_Jl_Q_~~~_____ ______I__~_o~S_J frOID lDean
Percent Percentgt458-1 ~65 +41IWtl-li 130 -a2Hli8c aliO +26S41i8-d bull 130 -32
1(-011 34I10Olifgt __ bullbull __ ~--====
li-9~2n 881) -06 li-9~2-b Si5 o ~HH2middot(middot S i5 -6$-H2middotd 000 +1
8851 054
O i5 +6 9 i5 +6 950 -20 U75 +6
H-liG3o-n bull -1 n-li6~b bull __ _ -IH-IWH +4H-l61511 bull -1
1tmiddottlU
62~-lI __ 62~-b ij24-( bull OH-Ji
(-Ull
I rll(St oluls nre tor separately ~xlrflCled SllllllllCS IlctOrdlug lO procedure outllned ou pages 4 to 10 i Secoud number r~prtgeulS stulldMd error of lIe menn
36 TECHNICAL BULLETIN 920 t ~ DEPT OF A(]RICCLTCRE
ReUUER A~ALYSrS I~ CRCOE-RcuUER PROOCCTS
Sew rapid photometric m(lthod~fol the ddellllinttion of rubber and reii Hi ill uaYllp ti--ut htp lllell pIPHnl pd oil pag( ~l to In A brief H1111111tlY of It similar rnpid llHthod fm 1I1hb~rllnltlysis of u1lulcanizNl tlIldp lubbll pl(Hlmtlt whielt i~ bn-(tldo on the prill o
ciples dehtilcd tlllLe follows Duplltate nt-gm sllmph of the finely cliyiliNl IlInttlitiup wlirllll out [~ei-()l (all hl lIf((tinmiddotjv INd to lt1iyidl till alllpl) TIll kltolll-olubll portion of till )111(11( tlrc di-olved a- indh-Htpd fot thmiddot lllnkill~ of -tlllHlunlluhhll olutiou Oil Pt 1II hut tIl IUlIp Hn lIn l-fplImiddotd 10 lHI-ml rolllllltti( fln-k antil1ltld(lup to Olllll1l The bnlulUp or till JllO(ldllll i- thatutlilllll on paWs -1- 1 IHI Ii 111( 1(111 1- nIP IXPIP--pd nil til IHi or Iw oligiJla w(lullt of I Ill (I11l1p-I1l11Ilt1 1)(0(11(1
Hupitl PlllimiPJojgtiWllllllllh llIltllOd~ fOJ Ihl llPtlmiddotminntion of ImiddotUlJbll tlnd 1(-illo- ill -111111 Illllph of gutlYllll tiUl IIll dl-eli)ed 111() IlltlY d~o Ill nltlI1lld fOl III Iwl Illhlwl- and l~iJlmiddotb(lLiJlg plant TIllt l[Olllhup hns nlo b(l1l ntuptpl fot IIH lltlIll1illtltioll of lllhbpl ill 11lHhrublwl Pl(Jdlld~ HIIl 1111 hI ndaptld JoJ IIll ann lysis of ynt1J(gt( ic lllbbl[- The llllthmb HIP 1gtn(11 fill tIll fol1owill plimiph- III Grinding
tIll PIOPlly driPl t i~lIl 01 Ul tillg tIll pnHhHt to tll l((lllilllllh~lel of filWlH-- til plllllit qIHlIllilnth( lXIIHtioll 01 IIlbhlI 01 1(--IJl- () llsing oXWllutld olnuh (kttoJls IIt(talp and() fllltil for LIbbel and IH(ltIlIlyptIJllIllIoolYlnJld-o flJllh 101 niJlsl with t(lathelr high IlPililig points 111 to n C) l]olle or in mixt tIll thllt Pll mit tlll rnphllxututioll of luhll(l OJ [middot(ill ill ~() to (l mi1lutp It r(latiwly high 1lllIllllltlltP Ill to 1~11 ) l) lllllipitntillu till luhblI OL Imiddot(ill frolll aliquot () f till oltn ion I IlIlllI-i () f Hlltabhmiddot pl(~(i]litallt (willifhmiddotd lthmwl fOl IIlhlHI Hild llitlifild lllr fOJ JP-illl t~) IIlHkillphotollllliilPIIIIiIlof PlllPlltal of liht tLaIlS mittUl(P lIftlI IlIlbll (II Il in PIlipitalioll 11 II WI( Iplllh thnt (limiJlall till PIIOl dill 10 xtralllOlh (0101 (till dptl1minntinll Iph jill 011 tIll dtwlopllIlJIl of H HIli rOI1ll tlllbidity 111 hpl than I (olot rI
jJlIlpOP-ofallnlyi-I ( p(lllil1thb IIllijOI1ll turbidity or 1llt[lIinmiddotd d(ltl of jgtIp(ii(JlI l)~ lIltlkillU tIl plllltollllmiddottri( ntdillU al tandinu tiJlH~ (dlllilll wlli(h IhlllH(lill-- IP 1llutinmiddotly tnhll) t1ll1t an hlsl~1 oil the (oJlItlIlllItion of IIlhlHI Ill I(ill (lIPIipitat((L
TIll -I(p ill till jll()(Plhul HIP 1-- follOylt (1) 1l~UIIL uJ1lplls of thwl UJfJlllHl (II tliddl(l HUt dlipd 11Illtplial an lXIllltel with11 Ill of till nlnll ill t (oU tlllltIPlll[gtPImiddotatlup oil Iath at 11 Cbull fol 11 minutl I) iIP1lIin(middot(lohd til( (XUtllhllll Jltldl lip to It middotml ynlmlll til( (nlifild by (Illlifllgiuu HlId thlPl IlI nliql1ot of tIl (IalioPlllxUlltl nll Uillltlmiddotll(t to l-llll OIlIIlIllril fiuk- (1) For a trial Ilnditlg 0111 III tlll j liJmiddot~t IllHII IIjI to Ohlllll with lilt Pll shy(ilitnnl a 1(11 it 111 (Dod fill llli lIut ( ptotoJIIltlil IPtlllillg-- of pllllntnl or liuht tlUtllIlillal(I oil n (lpel OphotnJlllllI at rase hng-tlt (If 11 llJ Ill Ol It lollllil1lPtImiddott lloyidld with tIll P10]11 I 1110110shy
Ihlolllltt hmiddot Ii1llI Olllhi lIatioll for -1IpItillg UJlproXilll1l tply Wtl P ]Plwth )0 mp are HHlltk TIll Illldillg lliJtaillld fol tIlt 4-milutl tliall(~ll-
bull
bull
bull
RAPID PHOTO~IETRIC DETERIINATIOX OF R(BBER AXD RESINS 37
ing are referred to a table of equhmiddottllut~ previously p1(pa1elt1 on the
bull basis of 4-minute reac1inJ~ for tilE nmge of lot1telltlatiol1- of rubber or resins to bE elHOlll1t(led tmd gidn thtmiddot -tnnlillfr tillIP fill rUbbEt or resins aiter prE(ipitlltiol1 lwfolE photoIllNliI j(tltlill1 un IUade The r(middotnmining dllplllatt aliquot lll then HHllil up te ol1l1Jle and lpoundadillg ale marle ut the -tandillfr tiUlE iudklltll ill rhl tall1lmiddot for the final r(adillg~ -1) 111( milli1lnm or p(tCPlltllt- of lllhbpL (II 1(-in pr(s(nt are rpadholU a prlpan(l table of lquiltlput for tlll photoshymetric readings h1~l(l ill pnell e1-E on pxpPlilmlItal lhln 1111(1 u-ing as stimtlltlds pure luhbll in 1l1bbtl milllYb aIHI guaYllh ll-ill- lxIHlatt~ in resins detNIl1111lttion I
LlTERATlRE CLTED
(1) lUnSbull 1fl36 THE mURMIXTIOS IIF IOTA RE I III OOl THER llT~II
F1 bullrol IlY U(T1l0fll UfSlfi ~rrnrl r flm lt1 KEYS TI Bill Chern 114 44J-l59 illns
t1 ~ICPHHlObullbull T 1J3bull~ lUTHOO roa THE PtRInCAnu Or a(lIUl IRrIlHU It of TIn
PLRIHEU Htllllflt [ i Bill lallllall 111 Rmiddot 711middotj iIlus
I ) RHBERG P B Ul5 A METHIlO Or ~u(ronrll-nl Hi tIII rUIl[1 f71 ii illlI
bull 14 Hoss W flbull and HARDESTY J O
llH IR1ltDII Of HfITilIZfmiddotR DllIJS ltt 1 Yl fll Off gI bern JIIIlI i ~middotmiddotlf IIl
101 SPEltCE D nnd CuoWELr ~I L 1933 DETER~n-ATIOo OF RtBBER Ii nrllllpoundRBfR Iusr 1uI II1 amI
Em~ifl cttIliIa~~ r Ell i 71middot7i l11 (HI WALTER E D
1U44 ISO~nlS OF PRTlltSrr 1trHpoundV bull l UI n W lHHt (Tnmiddot 1ETS FROM GiYI l~iIl lItr Clttrn SII J UI titJ middotn9--C1 ilIu
17 J YOEbullbullr H lO~( roLORIlETRT 771 IPmiddot nl -W Yurk f H Plrwptric hmica
naly-II rimttry lUll XphHHlnmiddot~ y 1 1
11
HI) ~ fPHELolzTRf 57 111bull Lin xw Yk t H lt PhmeHt CblUlmiddot ila AnaiY~l~-(H lithrry and XIhmiddotILpfIY Y wirh enomiddot rrJlllrjr hy H KtlJnJU11 I
t~1I --- and ~ARVER L 1f41 nlua-w ~in L liLhr IS IP ll~ XIW Yrk
bull For-sale by th~ ~a~fr1nt~nf1ent Dt~c~~ogtnts-~ s t1i rArnn~ut Pn~~~ tJffieshy
Washington 5 D C bull Pl lU ~nts
6 TECHNICAL BULLETIN 920 r S DEP1 O~ AGIUCULTUHE
in the Writl Inborntory) al1l1 fiUerp1 A [j-I~re(gtl1t solution of this by volume is then made it thu k(tone Htptate or l(hPI or tht llIixtlll or tlH~p I~lll as tlw lullber foinnt
REAGENTS HHt RESINS ANALY3IS
Resins SUITIIN- Illixlule I)f a parIs ot lll(IJII~lIllII(JIll Hlld j pnrl~ (If fthSi IllI glnmiddoto] IlHlll1I1thII Nhpl (l(rtiIlHft(l 1CPIlPi i 0 as (middot110lt01middot1 I hr 01111111 botl t((hni(ul-glu(p CnlilOlI amp VHIhi((I h(lIli(d~ COImiddotpl is a gooe1 r(sin~ soiYPllt ~Ihis lllixtlll(I i~ 11(111( (0 ilS 1((loll~Il(ltlJlIPmiddotllll(Jllmiddotl amiddotmiddotj ill thl ((xt (011shys(allts I)f thf~( a 1111 011](1 rl~ill oYlll(s tn )inlI ill lalJl1
R(IIrmiddotpimiddot((middotJitlltill1 iWiIiOl- [i-(J(middotl((middotClImiddot 1I~O (e p (agln Oil Ponl f1 gl 114 J solul iOIl in HO by 0111111( is UStl m I Ill llills pll(ipita nt
Po(- i ( (ol()icl ~lJ11I1 iOIl Ol t(8Iyen-A O-IlPI(lnt olnl ion of (igl~((1 Rtrl ra i ( H or gly(o~t tlill I lIIath ill I (p( ollyln((1 OIl(middot(plJool( j or nlly ot Itpl rlsills solnnl 1I(tL TIJl diglYlol Hipn Ill ((i ~ is (lis~nlaquo hl 1 Itll tillg Illl lolLttioll i 11111111 liP 10 ulnnl( nla Ht1li1l1H11i tl1Il1ltIIItlllP Hilt 1IIllI((1 If thl -oll1liol1 liOllltl )(lOIllI loud) II((IIIP of II drop in ((IIII)(IH(III( 11( plPtipinll may hI hlollgltt IIHI ito ltulutioll hy It(lItill~
SIECIL EQrllIE[ Fon HlIlImn 1) HESS AALY5IS
11I0T())t1~TIG ISsTH L)IEITS
8((1111 tylllS ofi IlstllIIllllltS i Ill 1lid i Ilg tltl C01lIllflii e ] (((Ioni( plW((lJl tI OJOill(hI (oJ II1Illll dolllJltmiddot II lOll el(h1011111 t OJ SPII( IOplJOtollwtpJ Klett-Sull1llllrSOll o1olillltlI and EnIYIl pllOt(l(h-tJie cololimettt han b(PIl II~~(I TIll pilotoflttolOIlIltll apptUPlltly is llot suited for thl pUlposr iJltHlIP thl (hllJlIh~Jjstj of n( l-ollsplllliOlI IlHHStl1lll waS SLl(h that thplp WlIS velY ltLpitllhullge ill the rendingS oil standing of the liOlllt iOll a1tlI rubbl1 nnd Il-ill~ plltipital iOll fltP onitL of prefmiddot el(llce fl(lIll tilt ltalldpoillt of gllntls pllri-iol1 of llading~ is us follow
(1) CoWlIlan dOllhlt 1ll001O(ltlIII1lH I01 IWl1 Iuphllt 0111(1 PI mo(hl lOH 0 COPIlHlIl I1I1iY(lsnl SP(ctI1I11holl1nHt(1 Ilwdll 11-WaYlmiddot1I1g-1 It Rlllinl II t j() mLL is IlCIUlIllPlldl(i
(2l EnblI pholo(lptlli( (olulilll(Il1 wi It (Ining- 1II11 110(IIIUIlHl tie filt lr rOIllshyhillatioll jtl lIllL 12middot112UGc51- villstllt (ap i~ ~(t1 10 ((Jlr nl)lOIptioll IIt tllllP Wlllll 1(IIilll~ HI hlill 1lI1lt1t A nitmiddot fill holding 11 Itlllll nmgllifing IIHli til flllilitatt lIlaldll~ IIPPluxilllllll 11llIII11111letl1 I(adings tn 01 lila) hc IIJ1l1l1fll(lllld 10(lllIy
(H) KlpttmiddotHlIIllnllISOIi (OI(lIilll(tP-So ~Ililllhll Iiltpl (lInrllinnlion of IIPillllXimiddot nwlcls 50 IlIJL IIln( (Ilgth I atillhl( at 1Il(middot~(middotIlt Till ill(ItIIlWllt IWIfOIIlIS Hn tisrt((oil~ wit It th( IlIa iI II 1111 filt hpi ((11 iji 111111 njij IIIl for IlIlIlI(I II nIl1~si on 2-S(tllolll (Jl oltlll glltllh 11111 (prilll wit hlt l(lJlo((1 a 11(1 f(IJ~ currentmiddot plon ~1(jlh (101l IIII plnn[ with 111 t (1 ahlllp W(J IllJL 1l( lig Hl llIi 1illlit it USP(IlII(S$
ltOl the JlJ(~(Il( tlt( Ewlrn pllOtolIl(1 de (oIOlinwhl i 11(Olllllll1H1(d as (hI IlOt eOt1PlliPllt alld ndaptabltmiddot il1trlIl1lnt rOl rout illl lnbolttmiddot t OIY alltl ly~(-
OTIIEH I~QUIII~YI
A lhplllIoI11 i(ally (oll(lollltl tlil huth wilh a l(llIun1l1l (1(11 hllsk(t pllllimiddot liOlWl [0 hoW il)Il YOllllllPI( lIa~k~ ltig ] L llihglmiddota(]( tylil(il oil ~ K O i1((1
A tlt(IHW(1l tielHr (mil 1lIl1td 111 Ipl 1Jr t It IIIIIjdlt wir It lHolol iImiddotI(1 Illld IClllollhl ~(lllI IlIl~kl[ 1111 lt it jllll(( t h()1( i II Ill ltlOmiddotml Yonnrp[ riellllisl)I 11( in stnlltIItlllllg I Ill I lPlI (II 11 of IPII)(l1tlt Hila IIn)UIII of (xIII(Itl saJlpp~ Illkpl1 (01 Ilnlll~~i~
bull
bull
bull
7 RAPID PHOTOME1RIC DElERlHNATION OF RtBBER AND RESINS
bull
bull F1(rJm 1 ~ UIIIltan 11l~IIlInIPIII lo UIIlallt-lllllplalul( ~(II(Inl-[lllrpose hath 11fil1l liS au oil hath Xlltl ~IHinl 1(IIIOIullll win 1Jt[PI 101 holding ~[j-lJll Yo1U1l1plllt flask dUIlng- (xu iOIl ur luJhl t IHI IIill IlIi is uot stlludard ltfJuillll1ll1t nIHl 111lIt hi 1Ill((1 b1 (hI Hllal~-t
Ilm1ll E JIItnslIlPil iIIit (111([ (Iltaslll(11 [1111 In(J nlHI K()(lak electric tinwl Ilw Hutpl H~ 1l~Id ill I1PIIIllIillillg )1IIIdillg (illll n((uInl(l~ 111 111lt minute unll luhllpl HIII1 Isllll al( l11(ipIIIIlP(] 111111 till tOIlIlPI 101 tinling hlHtillg nml (11 tli fUli Ilg 11l1iulls
AWill~ 01 It Ball amp I(wpllluill fol Ull initial lWUSI glinllillg of gtllyul(l UsU( Hoss-llal(]pslr IIWllifillIlioll of Ihl lInlllllHI 11Iil I I plIlIilll] with Xo 1
(~middot1Il11l) nl1d XII (iIIlIII1 (lPIItS LYIPX i lUl(l lOOmiddotml oInllHUilt 1IlI~ llloidltl witlt grolllHlmiddotglns RlOPflllS spr-ial mIIIi 11lx ItitUllIti IIllIkll wllh UIlI illlIlp 1111111 1111(1 gillS
10(1 12 CIIl iclllg h~ 1Ii jlll ill Ilillllllitl wHit gtOllIHI UnllIIPti IlId 1 em In dillllllll fOll1~p illlllllldllg lIbhll slutlon [fig A IUHllJ) 11)( jllpiul heakcr I lIJIIlI1fIIIIIlII11 t101Il Ihl W-1l1I lldUiIl low-fllllli 1IllkI wilh s[lout laquo(olning (llas WIllk Xo 11111(1) Till ll (toul I flatlll1lt1 hr (Ill lgl1lu glllliliIIOl[ing Plo(Il1m Ill IillltllIllI 11111 of Ihl gIllgt ruti aIHI IIIP sUIfa(( lit til( lIat insitle hottnlll of IIII )11111 nl( gIlltlIHI toglll)I wilh Itll(I~ ill 01((1 II) s((Ule the most II tisflnlory SulfH1 rill lil Illl I iOll
P~I(X WIIlIIt glI III 111( ll111L ill thilkms 10 II~( a It tIHS(~ III ([hiding luhl)(I Sfllll[llp
A Iolk Imil fill lISI ill diiltlill~ luhI 1111[111 H(Hy(Inl~ 1~T(lX 10middot1111 gllhmlllI (Pili Iifugp t 111H Ill]lillld wll It (011(1 1101111
lind (ork tupp (0 tit I Ill 2 ()
bull Filt1 tilk (fig 2 IJI 101 1)( with Ihl glltllunlld tublS ill thi o[WIati()n of
llOUling lIIIlillpli lx(nll illf jIIlI )lhIIIl1IY(I lIask IYIIHIlt ([illlluin l(slmiddot Ill At hp II11IPI a )Iuss lOI wit h I tIaltllll(l (lIll lIlS lI1ullIfnlul((l ill the Illhllln(()I~- fol this l1SI bill ii In (lilli(ll1t 10 -1(111( II PIIpound((( tit Howlwei tlte anilnblp filtpl ti(klIt1 tlll 1)111)111-1 lind was Intll lIhs(i~llll(l The fritte(l glass disk SII(S 110 rUlli1 lUll Ill llIlI in tliH O)IlIUlhJll hut hollis hlllk the liqllid II nil lPidlH in till ((111( PHill
Cuullipl(1))ipp(ll for tlllII~flJItng klotlls nnd uthI IlIgnnk Illnnis SlIInl pighin) III I (h li (Ill high alHI (III ill ([111111(1
8 TECHNICAL BULLErIN 020 e S DEPT OF AGIUCUUlUlUJ
bull
IHHH middotmiddotmiddot~Ollll of the ~Jl((iHI ~lnsswlI( reshyquilpd 101 [lh)lI and I(sills tllal~sis (lllss rod wilh lInttPIH(] (ml Loll alld tlitulatioll lJlll((I II]) 101 liSP ill bull IIlnlln~ sto1 solutions of IlliJlPI (olII1i lwanshydlltr -AIIlI lYIX ((1I11ishyrllg tulJl wit Ii 011( poillt (0) nIHI flIIpI stie ( J) I fOlllSP ill P[)lIill~ utl (llIdiIli (X( lels witlt shyout di~tlllhill~ the inshysulilhll Ipsidlp
bull
Glns pound1111])(1 ) jlllll in ((iamptl for 1( ill tltlm~rprljlJg- pighpll fllJlplpS HIIl1
bull (lnrin(d IXIIat to -llil ohllnlllI f1aI~
i(p-mollllt gingt hntl will llntit OJ 11I(lal J(IP (n] fOI toling- gIollIH plallt samp(
Halmiddotk for hllldhlg ill-llll middotPIlIlilnp nlHs IIIH ~i-1I11 YOlIll1pllit flll (Jig- 31 Alltolllnti 10(1-1111 ~middotI(lX IlIllPUp of IhI fq)p llsltd fOl Iitis with intpl(middothallg(middot
nh1t H(JlIlHI joint 101 rl1phl lPfIPIIIlg (lj 1lIhhpl fllld 1(ill lll((jpiltlllls
bull
FllilHE Had Iqllind fool IIJI(lill I 11 (111111111laquo llllmiddot alHl (I) limJ VfIlIlllllJi( tlak~
bull TIll itl1jHlIlWI of n Illb tlpl of d(Hdill(~~ III [gtJ(Jtnllllllil lllll~
i dblmiddotwmiddotpt hy Y (J( I _ j J i) t Illt riflllmiddot t tth~ n n Ii 11 111 h111 I t1loOIlldy witl nap lllltlIHI 1111 1l1id bpll tlll- HII lill(ll with (jtt11lill olutioll Hlld ltll If fla k It It [lllijljtnlld 111bhll nl
11ill lIll til ~tlllld all 111th Ill lillI Illmiddotforl 111l In 1(11 it j~ luhmiddotjlIll] 10 1111 0111 ilH (111(11 11[ Jpli~ Ii tllp wall TIll
10 TECHNICAL BULLETIN 920 U S DEPT OF AGRICULlURE
25- and 100-m1 volumetric flasks arc rinsed two or thrce times with tap water and then with cleaning solution al1tl watel as is customtny In all cases the rinsed glassware is dried in an inv(ltell position at 100111 temperattlre 01 upright in a drying oven The flasks used IoJ extracshytion of rubber Iron1 kok-sagh)z (Talllrl(((IM1 kO-8aghyz Rodin) are finally rinsed wHh the solvent to be used and are nllmnd to lt1Inin and dry under a ventilated hood Cuwttes 01 absOlption test tubes nre handled and cleaned aH directed by the manufacturC)s of the llhotoshymetric instruments used
RUBBER (CAOUTCHOUC) CALIBRATION CURVES
GENERAL CONSIDEHATIONS
The lubbeL hyclroc~rbon stau(ild is pllpa 1((1 by extracting the rubber from guayule bssue ac(ordll1g to tilt SPCI1((-Caldw(llmethocl (5) 01 by the Holll1lH-HaasiH modification of this method (p 2) The air-dry extraeted ltlbber is dried furtlllr in It vacuum OYCl1 with 30 inches of yaCH1Il11 at 63 0 C for 4 hOlIlH Till rubhlI sbindanl is preshyserved h1 It clos(cl contaim1 sto1(d in It r(fligellltol BCfole th( samples nrc weighe(l out the unopened cOIlbdn(l with the rubber i~ brought again to room tllllpelutnre
Two stock solutions each in triplicate from separately extractml standard rubber satnples nre prepared-the first sct of (-111(( containshying 01 percent 01 1 mg of luhbC1 ])(1 lniHilit(l and the other 02 pershycent 012 mg of rubber pel miJlilit(l TIl( (I(~il(d w(ight of rubb(L contiiinec1 in It known VOlIl11e of th(~ solycntis withdrawn Irom Il
burette or pipetted and made up to 25 m1 the standard volume used throughout the procedu]e
The rubbcr samples (01 and 02 gn1) for the stock solutions are weiOhecl out to an aCClllal) of o~ mg on nn analyti(~al balance The rubber is best mnnipulated by mNlI1S of t1l( stJai~ht hlunt-edged top of It cork knife With a little prnctie( OIl( (an leltlily sepnrate t)w desired portions by pLeSSIl1C from aboye Further subdivision Is mndt on a stout PVllX at(h glnssnt lla~t 2 mill in thlkne~s By pressun f10111 above and sheuling aetlOl1 Ye1~ small pnrbcllH can be separntetl so that the requit((1 11l110unts (un 1)( w(igh((l Ollt accurately The rubber sample is then divided into sl11a11 piC(es on the special watch glass by meanH 01 II coll Imife
One mil1ilit(gtl of lt1i isobutyl ketone 13 js placed in It special 30-m1 trituration beaker (fig ~B) and the fine1y diyilt1ec1lubber sample (01 or 02 gll1) is udd(d and heated on a hot plate under n ventilated hood to Il tempelature jllst under th( boilin~ point of the olvent A special glass rod il used t () t rit II ate the sumple (fig 2 11)
When the rubl)(r hll d issohed so as to makl a hOll1og(J1lOUS geUike 111I1SS hot methyl isohutyl ketone or an oI the other luhb(L solvents recommended (t aIJI( 1) is add(d and niicd with the rubber soltItion
31 Diisoblltyl ketoul WIlS not aailab1p (Juring ValtimC l1Cthyl isolJutylletonC 1II1ly be substitnClt1 11111 it is not a~ Cf1kiCni In Illis olllntion If the IllttC1 is used It is b(SI to pl Ilw fimlr diillPll Iubhpl palll(s slan( oPIuight in Ih( solvCnt lind 10 (OPl til (onlalll1 to IllinilllizC elIpornt(111 of sohPIII bpfolp wa( Is nppliecl to completp nlutioll
bull
bull
bull
bull
bull
bull
RAPID PHOTOMElRIC DElERMINAlIOX OF RUBBER AND RESINS 11
The mixture is tllll1sterled to It 100-ml yolumetlic flask with sevtlul washings of hot solvent cooled to n s(uHluld telllpelatUle and madtmiddot up to volume with the saIne solwlli SlwtiaJ IHl(uutioll mllst be takell in transferring t)( lubbCl solutioll to till YolulIHtrie flask so thnt llO rubber is lost It is cOllytllielit to illSllt It j-ill(h funnel in the ne(k of th(~ voiumptic flask to pOll tll( lubb(ll solut ion ill OIl( OLWlHtion into the tube of tht IUlll1ll with Ihl aid of tIl( glllss Iod nlld 10 follow illlshyl1eilintely with S(gtllnl ~Ynshings of hot S() I(111 whkh lIl lilst pouled 1nto tIll btll PI 1I(ld dIIleUy OW) till 1unn1 aId IhpII t1I1uugh Ill( funnel
H time hi not all objllt it is uls() flasible 10 p1alt Ihp linely diided particles of Iubblt ill tl( flask toJ1tuining Ihl sohPIlI 11(1 allo it 10 stand until til( 1lIbbpI is dissolYld TIl( llIblJll ioluliol)s alp slolpd in Ihe tightly s(ojlP(1(d OIUllwt lit f1nks in a ((lol dark placl Thel they willltIIlUlIl (OlUilallt ill Idut 101 an indlfinit( JlPIiod
Two ellliblHliol1 (IlP~ flIP IIltl(l(-OIl( 101 o~ gill of tisHlIP (ollin illshyhw 0] to 10 PII((Il of rubb(I ((1lt)middot1 to U mg of IlIbb(Iill tt ~)-1Il1 yo1ullll) and th(middot otlHl for ()~ gil) of tisslIp (ollaining 10 10 ~l() peLshycent of lublJPl (O to 10 Illg of lulllJpI ill a ~)-))Jl YOIlII1IP)
(Hns HlJ 111 TO 1 II~IWEX( (II BIIII1EH
III oldl) to ll(llllP (ITOI (0 II Iltinil1lIl1l a lIitahl( lllillobllllltp is lIs((lo Jl((lpn (P IhI ~lt of stal1da Id solut iOlls 0 f a Ii ng (OJllllllllll ious ill til(gt (III)(r( Ol 10 1 gt(I((lIt of LubbI In (11( PI(sPIII WOlk th( 1111shypIoypd HlhlHIg mic)obm(ltp Il bullJ) whkh lIi(IlJalpl dlli(I~ 10 0001 1111 was Toulld sntisiadOlY F(OIll n lll-pltIllllt -talHlulIlllbwl solushytion in HSlIitnbh solnnl lt[lIiIlIUJl1iiat( aliqll()l~or n) Ol o~ n and ()t 1111 al(lllla~UIpd (Jilt ut n stalldUld ~Olllli(lll tlIlIJl(1atulp (~) C ill wlitllmiddots labolulol) I IlIIHIl-of II lllillOillIl(tlt illio ~l-lld yohulI(lie f1nks ploid(d it h gla -(OPIllIS gllollgh of 11ll lubhpl sol Pili i~ thllI addltl to (tl(lt flask to IlIak(1 l 1111 Ill1I IUI(middotc (0 t hl all)ollllt of lllbOPI solutioll ]ll(yiously nd(lpdbullflll DI ntl 01 JlImiddototlmiddottli lolloid solu tillil Iras h(PIl Hddld lIP (bhpl is JlI((i pi III tpd IIlld SP(middot(t )opl)()tolllshyd(gt( 01 (jIOlilllltp) IPallil) an IllHdp 1I((OIdillg to 11ll JlI()(pduJ( Oil shylitwd Oil pagp 1middot1 Th( 1(ldillg~ 101 palmiddotll (OI1((III)Hlioll alp 1I(Iaglt1 anel plotttd Hgaillsl t( ntilligllIlll of 11))1 hI n ~)-1ll1 (jIIlIlH 0) [gt(lClntagl of nlbblI (nltuln(pt 011 tw bnis of tl2-glll lilsul Slllllp1(gts and aliqilOt olulllt IH(IOI 101 (itl ]1I(J((dlll( out lilll(1 Oil pagl 1middot1 This PI()((lhll( i ((l(alld t win ill (a(1 (11( II slandald llIbbllsolushytion was PI(gtllllpd IIOIlI slpa latll XllH(1 ld 1 a utln)(l lllbblI 1 III pips TlwcOlllpl(tpdtlla alp pol(l (1) (loldilla pap(laslrowl1 ill figulp I
Tbl )llO(p(II I ill lllilking a (Uln rOl I to ~ jiI((lIt of JlIlJh(1 i~ simi1t1I to (hat rOl 1Ill l1IlP ImI1 to 1 JllI(PIII (x((pl ill a f(middot dptnils The quinlu]lli(Htl aliqllols a 1( sput(d Ht (lI 12 a j 0 (78 n alld 10 mg ])(gt1 ~i-1Il1 Yolunl III sNuIing thp 01 Illg pll 2)-Jll1 YUlll))lt til( (gtIO(ltlIII( outlillPcl ill IIIl PIp(tding pnltlgllIph is followpd In the rllngl 1 toj Illg )IN ~)-1I11 OtIIl1I Ilw (lsi 1(lt1 (oJ)(tlllltlliollS of lubbpI alP s(gt(ul(gt(l h IlIPHsuljng alhplOi- with Xnlional BIII(atl of Stnndlld~ tltllsf(I pip(Ws flOIl) tltl OI-PlIl(1l1 lII))ll sol III ion
12 TECHNICAL BULLETIN 920 U S DEP1 OIr AGRICULTUHE
RUBBER IN 25-ML VOLUME(MGl
100 1~__middotOT5___ITO___15__2~O=--_bull 2r5_---= bull 3rO__~-_40 bull99
98 shy(I) CI Z
~ 97 ItJ II
~ 96a f-IIJ
e95 o l
94
93
92 ~__~__~__~____L-__~__-L__~L-__~__-L__~
o 1 2 3 4 5 6 7 8 9 10 RUBBER (PERCENT) bull
FIGURE 4-Cnllbrntioll curve for rubber in 02 gill of gt1n~ule tissue containing 01 to 10 p(rcpnt 0 lllbhlI (nlnllillg~ (Ill 1111 J~pl~ll llhooplf(middotttmiddotlc colorimeter with 720middotmu filter und amiddotml uperture the 01 divisions required in actual pracmiddot tice for photometric IclHlings arc olllittltd)
Similarly hl the range 5 to JO mg pel 25-ml Yolume the desired conshycentrations of rnbber urc measured from the O2-pllmiddotcellt solution The complete data lire plotted on semilogtllmiddotithmic pttpel as shown in figure 5 A
STANDARDlZATJON AGAINSL G1IA111 ETlIIU 11 ETHO()
1he alternate ploee(lule of stt121l1ald izing th~ IneHell~ method ngninst the Spellcc-Cald well method (II) altholl~h flaSI hIe 18 not adVIsable because of the extra work J(quiled ancl the introduction of the expershyimental error of the benzene extraction method
HESINS CALlBllATION CUIlVES
The procedure for constructing cal])lation eUlves for resins ttIlulysis is similar to thtni outlinlltl for lubb(l lxcept that resins exndate of gunyule is lIsed as the resins stundard The resinolls exudate disshysolves very readily in the resins solvents listed in table 1 It may be prepared in two ways for use as a stnndard-the clean exudate as bull gathcrcd from the plants is dried for 6110mB nt 65deg C nt a 30-inch ltcuum or the oXllllate is dissolved ill acetone and filtered In drying
bull
bull
bull
RAPID PHOfOMElRIC DJllImlMINAlION OF RUB BEn AND HESINS 13
RUBBER IN 25-MLVOLUME(MG) 2 3 4 5 6 7 8 9 10
r~
eo en ()
90
f--70z Q ~ 60ltl LIJ a ~ a LIJ 40 E 0
0 50
~ 0 ~ I 30 0 ~
A 20 I I
o 25 50 75 100 125 150 175 200 225 250 RU88ER(PERCENT)
RESINS IN 25-MLVOLLIME (MG) 2 3 4 5 6 7 8 9 10
1--90
80
en () 70
I z Q 60ltl LIJ a
50 0
a ~ LIJ 40 E 0 0 ~ I 30 0
B ~I20 o 25 50 75 100 125 150 175 200 225 250
RESINS (PERCENT)
lJIGunE u-Cnlibrutioll cUve for (il) rubhcr in 02 gill of gllnn11c tisme conshytainingl to 2G perc(lt of 11IUU(Il I1na (1]) rpSillS in 02 gill of glI1~l1ll~ tissue (ontnining l to 20 nelecnt oC l(sin8 (U(ndings Oil 1111 E(lI~1I llhotollectlit colorlmeter with 720-mtL filtcr and O-ntJ aperture the lO divisions llquired In uctnul prllctlce for pitotoulPtlie PllllillgS tlre omitted)
in vncuo arelntivply HllHlll qUllntity of (xutlnte is plllcel] in a lalge dish since the mass rOHmS nt the beginning of the drying process Pracshytically ull of the ne(tone is evnpollltpd olf oyer a steam Ol WItter bath and the residue is dli((l pnlYllized in It mortnr and preserved by
14 lECHNLCAL BULLErrN H20 U S DEPl OF AGRICULTURE
drying as indicated for fresh exudate In all ClSeS the products are stored in airtight containers in a dark coul place
The usualllnge of resins from gunyule tissue is about 2 to S percent on a dry-weight basis For work with this plaut therefore on1~ one curve is needed A typiCallesins ealibrntion CUlTe is shown in figure 5B
PnocEDuuE J~OH RUBBER ANALYSIS
Duplicate lXiLllCtiOllS arc made for each tissue analyzed and duplishycate photometric readings are made for each cxtmctioll the final value therefore reportcdreprescnt- nn avcragc based on the four phoshytometric readings
Thoroughly mixed O2-gm samples of the finely ground tissue are weighcd for analysis on the basis of l11oistUlc-frec tissllc The samples arc weighed to an accuracy of 02 mg Oil an analytical balance The method of deriying factors for making eOllections for moisture in samples has been thtailed on page
The weighed samples arc trallsien(c1 to the 2-m1 volumetlic flasks with the aid of l-inch glass funnels and 20 m1 of methyl isobutyl ketone is added to each flask The contents in the Hasks are heated m a constant-temperature oil bath at 115 0 C for 30 minutes uncleI a yentilated hood rhe flasks are removed and any adhering oil on the outside is wiped off with Kleenex 01 H similal cellulose tissue the C011shytents of the flasks am cooled to a standard tempellltule (25 0 in the writers laboratory) in a constant-tempelutllre ater bath provided with a motor stirrer if available and made up to volume with the solvent After the contents are mixed the flasks are allowed to stand for a few minutes until most of the insoluble residue settlcs to the botshytom The extracts are then carefully poured into JO-m1 heavy-duty centrifuge ulJls so as to include as little as possible of the settled insolushyble residue The centrifuge tubes are stoppered with cork stoppers and the liquid is clalifiecl by centrifuging for 10 minutes at 2000 revoshylutions pCI minute The clarified lIquid is poured into 25-m1 volushyl1Ietric flasks plOicled with ground stoppers It i impoJtant to pour off the clalificd (dlart in lWIt a lUlllie that the ill8ol11ble cNi(hwis not Sti1((Z1tp A 1-in(h funllel is plncCd in the neck of the volumetric flask A filter stick (fig 2 D) is inserted in the centrifuge tube through he liquid so that tlH enlnlged palt of the gtiek seals off the insoluble residue and a small portion of the exmet in the cone point 1Vith the index finger the stem of the filtel stick is thell held against the side of the tube towllnl the analyst who holds the tube with the thulllb rmtl t11illt1 fingCl The txtlHct is thell poured off easily into the yohunetlic flask without distnrbing the insoluble residne The COllshytents of the Hasks are then ))ollght to the standard tel11pelatme in the constant-tempentl111e wnter hath
The reagent blank us(d wit h the spectropllOtoll1lter 01 (olorimeter ig prepared as follogtvs ) 1111 of methyl isobutyl ketone 01 other solvent used is pipetted into It 25-m1 yolumetric fiask and 01 ml of protective colloid solution for rubber is added the mixtule is made IIp to olume with acidified Oil-pelcent ethnnol and mixed again the rcquired vo]shylime of the mixture is poured into a cuy(tte or an absorption test tube
From each plir of tissue extractions to 5-1lll aliquots 01 the clarishyfied extlact at the stnndanl tempCraLule ale pipcUed into 2ii-m1 volushy
bull
bull
bull
bull
bull
bull
RAPID P1IOTOMElRIC DETERMINATION Ol~ RUBBEH AND RESINS 15
metric flasks and 01 m1 of protective colloid solution for rubber is added to each One additional5-mL aliquot from each pair of extracshytions is similarly prepared to serve as a key to the standing times for the final readings as indicated in table 2 These additional aliquots are first made up to volume with the precipitant acidified Do-percent ethanol mixed by carefully inverting the flask three or four times] and allowed to stand for 4-minute periods before the reading is made on the colorimeter Vith these preliminary rendings a~ a basis the standing times for final readings are taken from table 2 For example if the colorimeter reading in rubber analysis at 4 minutes is 655 then the standing time is 15 minutes
The two rell1Lining duplicate aliquots for eath extraction are then made up to volume with acidified D5-percent ethanol mixed by careshyfuIly inverting the flask three or four times nnd allowed to stand for the required number of minutes as established by the preliminary 4-minute trial readings (table 2) before the final colorimeter readings are made on the contents of the flasks
TADLE 2-St(llllliIlU time for variolls (OllccntratioIlS Of rubbcr or rcsins aftcl iJleaipitation bcforc colorimetric readings mc macle
[5middotml aliquots of rubber in methyl isobutyl ketone or of rcsill~ in ncetonylncetonemiddotcellosol e 3middoti both made up to a 25middotml volume with pr~cipitantj readings on lvolyn photoGlectric colorimeter with i20middotml (690to iiOmiddotD11) filter and Umiddotml aperture]
RUDDER I
Range of colorimeter Approxima(e S~nuling i Rnnge of colorimeter Approximn(e Standingtrial readings after 4middot range in conmiddot tJIIIG for trini r(adings nfter 4 range in con tifillnlOalcor minute stunding time tcnt In tiSSU(l Unnl I t I t (rending IIlIDU C stum Illg lOW _ tent III Issue reading
Percent Villlits II Perfe~lt Jfinul 955-999 bullbullbull bullbullbullbull 09-01 00 01-03S bullbull ~ _bullbullbullbull_ Jl-O9 10 743-954 bullbullbull ~ bullbullbullbull __ _ 43-10 30 1420-550 bull ~ ~ 137-94 5 6_3_9-_74_2__bullbull_ bullbull bullbullbullbullbullbullbull_-_---- 6__8-_4_4---___ bull ~ ~ bullbull ____ MQrcthan 13ibullbull_-~_ _ ____ 15_~elow t~ 2
RESINS -----------------------------~--------
957-999bullbullbullbull ~ 139-01 60 11419-amp11bullbullbull _bullbullbullbullbull ~~ 13~5-939 10729-956bullbullbullbullbull_ Ii 25-1 middotJO 30 ~gtl2-40(L bullbullbullbullbullbullbullbullbullbullbullbullbull _ 2025-1320 5 595-728~~~ bullbullbullbull 8 as-G 20 20 IBelow 292 bullbullbullbullbullbullbullbull- More thun542-591 _bull ~ bullbullbull_bullbull_bullbullbull 038-039 15 2025 3
I Precipitated with O5middotplrccnt HSO in 05middotpercent ethanol When the npproxilllull concentrntion of rubber or rcsins in solution is not known trinl colorimeter rend
ings atmiddotJ minutes s(nnding till nrc mndelS n guide to the required finnl standing time indicated in the last column III prncticc UII cxtrn nliquot is prcpnred for precipitation and thIs is discarded after the trial reading is mnde
3 lrccipitnicd with OmiddotpcrccntlhSO ill HO
PnOCEDunE I-On UESIliS ANALYSIS
The procedure fol resins unulysis is the same as that indicitted for lubber analysis eomiddot(I]lt that f he -olyent js acetonylacetone-cellosolve ~)-7 tht precipitant js O5-perctnt H~SOI in H 2 0 and 01 1111 of the protective colloid solution for nsins is added to each 25-m1 flask conshytaining the aljquot of the extract before the precipitant is added
PnOlmmlHlC INSlHu~mNTs UECoIUlENDED AND CALCl]IAlION
OF UESurlS
Photometric readings of percentage of light transmittance (T) ale made on the Coltnum double monochromator spectrophotometer at
16 lECHNICAL BULLElIN 920) U S DEPT OF AGHICULlUHE
750-111 wave length or renclings n1( mnde on a colorimeter pLoic1eri with the monochromatic filter eOIl)Il1l1tioJl for sllecting the npploxishymate wfLYe ]cngth at 750 1Il~ For routine deterlllinations the Evelyn photoelectric colorinwt(r ployided with aTW-lllJ filteL is IC(0l1111HIHtll
The liquid in hich the preeipitnted lubber uld rcins are susshypended is pOll(d very cHrdully down the ill~idl of th( clette o absorption tube to lLYoilllllC fOLll1ntioll of ail bllbblls Aft( LUbbet find resins preeipitation wlwn the EnLynpho(otkcllie (olo1imetll is used the readings are nmde nft(L thl standing tillll- hOWll in table~ It has been foulld (OIlllliellt to 11lPtipilatl tublwr 01 llsiIlS from the aliquo(s at ~-millute illtlLvals This allows stlilieipnt tillle to check the eOlolimet(r and to makc 111( lNHlings Vlwll a ehangp is IlltHk fLom onc rending 10 the l1lxt it is advisablp 10 llle the clIvctte 01 absorption tube nt lpast twkp with slllall p(Iltion- of the llllltiol to be leitd
After the colorimd(L lluding lta e becll Iltndp till IlIl II igllIlllS of lubbel or resins or thc lpL(el1hlges pnslnt in Ihe aliqllot are r(u1 from cal ibmti(Hl (urVlS (fig~ 4 and raquo or from plepn Led tables of eqllivallBts baecl ill each (liSP on (x[lerimPlltnl data The results are expressed as percentages of dry weight (S hours drying nt 100deg 0) of the original tissue The errol lltle to lCflyjng the insoluble residtH in tbe voltlllletLie pxtLHclioll flflsk wlwn the pxtrnetis being mnde up to YOlllmC is V(ly slight sinlte only (U gm of tissue is used FOLroutine allalyscs lhis ery slight eLlor mny be dislpgnltec1
EXPERIMENTAL RESULTS
The experilllCnlal reslllts Oil hi(lthp method- of tU)lPI and l(sins analysis a le based ttl( d icussld blicfly hlrehl
PHEPMINrlON OF SAlULES
No difliclllty was expPtitI1(ed in pltparing slmplls of llllrscly-glOrt guayule plants 1pss thnn ~ YPH1S old 101 rllbbpl alld IPSills analysis In the cnl of Odll filld-gl()n gllayull plants PIIOtS hopel mtty be introdmp(l by the custOlllalY Jlwrhod 01 pICpalillg Ihp sampl(s 101
HlutlYHis as is lwipfly i n( ita ttd ill th is s((tion Smh enOlS do llot nffCct the ])lCcisioll O[ t1H llwt hotls for LllbbtL n nd Il~in~ nnn I sis i nee till) are due solely to tIl( tbsup--ampling (llo(pdule in thi (a~e of oldeL field-grown plall TIll 1lllt1lOcl of salllplill7 fipld-gl()l1 plants JllOLC than ~ Y(HrS old thenfort Ieqlliles iurtlHl jnttigntioll
lgtAHnOILr~G FOR HEllOVAL OF UUVLgtS
Parboiling which (onisls in boiling gllltyule plants in water [OJ
8 to 1~ ~ninll(s ~s col1llllonl) uSNl a~ n llHans of Itlli rCnl()y~l prior to drymg nnd gllnllng It I~ tHI([())P ll(e~Sllr to ltItLeLnunc all possiblt~ eflct oi tlti PLOtPlllll( )ll (Il( final results Exp(liments have sh(nm that (helt i- fl Flight loss ill til tmiddotjght of lOO(S and 4(ll1S In I typi(ul lXpelillltll hlu1llHs of ~- ii) -1-ytII-old gllllll( pllllb were Italnd at randolll Olll ( of talns wa- paLllOil((1 and the le~es (1( haIHI-pi(kpd [lom till o( hpJ Ht Both pis (1( dlipd for 48 hOttlS at (i) C in a llI((lwlli(al (011((( ion Oyell Th( lpsult are SUI11111I11izNI itS follows
bull
bull
bull
bull
bull
bull
RAPID PHOTOMETRIC DETERMI~ATIO~ OF IfCBBER A~D HESI~S 17
Dry ucilht lust ill lariOilillf
Plaut (pcrcrllO 1 1 -I2 ___________________ _
213 _____bull _____ bull __ _______ ___ ____________ 12 2(
pound(111_ ______________ 1 R
4_______________ _______________ __ _____
A __ bull __ -_
The efred of parboiling on till final lllalp i SUllllllatmiddoti7(middotd ill figmc G Rubb(1 lecoYelY w(t about 1 percent higher for parigtoillltl plants and lEsills re(ovelY somewhat o-er 1 i)(lr(lllt 10Wlr The (Ii tference in lublH-l r((o-elY cannot be ae(01111tltlt1 fot by loss in dry weight _ due is to be found in a study of thE grinding lwhadol of a parboiled and an unpnrboilEcl shrub The grinding of the patboiled shlub in the hnml111 mill is much fadlitated and ns a rule for tissue with a rubber contCnt below 10 peteent llO aggregates of rubber deelop in the 1Il11ehinr during the (Jpelatioll Yitll the unpnrboilNl shrub some dillictdty may 1)( (lxppliellrl(l Sill(( sOllle of till sti(ky ltxlldutl Oil the plant may scI( u nlldei for the fmllHltioll of lublH1 ngglPgates Til is apparently explnins the npparlllt los in ruhbpl frol1l the llnpariJoiled hrllb as eompnlelt1 with thl palboilld (fig (i) TI1(loss in r(sins
II
RUBBER
10 f-
Ishyz LIJ 0 0 LIJ 0
9 --RUBBER -shy-------shy
-- RES INS -shy---shy-----_
IJ) 8 I--Z IJ)
LIJ 0
0 7 f- RES I NS -0 -shy0 LIJ III III J 6 f shy0
LEAVES REMOVED BY PAFltBOILING
5 f shy -shy - BY HAND PICKING
4 I I I 35 30 25 20
SCREENS (SIZE OF OPENINGS IN MM)
FIGlRE Ii EtIe(t IIf pnlticlp sizE Oil lEcorPQ- of rubber lind (iiil1s when lEgttiye wEre remond hr Pl1liloiling lind h~ hand pi(king ((Dlltrol) plllllt1lt groUlld in t hammer mill
6114038-46-3
18 TECHNICAL BULLETIN 920 U S DEPT OF AGRICULTURE
recowry from pUboil(d shrub may be due to the loss of the resinous exnc1ate during parboiling This exudate forms ns It SClim on top of tlw )iquol in the tank
On the basis of t1wse results the recommendation is made not to yaly the nwthoC of leaf lemoYal in any 011( lNi(lu(h project Then fltirly compalabh IcmLts should he obUiined
70 ~------------------------------------------~ LEAVES REMOVED
BY PAR80lLING ____ BY HAND PICKING
60
-I-Z 1amp1 0 50 a 1amp1 a
en 1amp1 gt1amp1
40en gt-CD Q 1amp1 Z
I shy 1amp1 30 a l shyx C)
1amp1 ~ J 20 I shy 0 I shy
10
O+--L__L-~__L-~~--~~~~~ o 10 20 40 60 80 100
NATIONAL BUREAU OF STANDARDS SIEVES (MESH)
FlGntE T-lJiMlil)utiun of l1Ultkh si~(s of gnll~II( tiSSU( JrIOllll(l in a Ball amp 1ew(1 mill to pass six dllIerNlt S(I(euroII 1(IlYes Iemoved from plants by palmiddot boiling 11(1 hand picking ((olltloll dpfo1iatld plants dried to 1I lUoistufl l0I1t~nt (If 01 to o) 1)(ICl1It ground tiSSlli IbalH1 1() minutes ill II ~i$hel
bull
bull
bull Kahn shuk(f
RAPID PROTOMETRIC DETER~UXATIOX OF RrBBER AXD RESIX-i 19
GHl~DIgtiG
bull Th~ entire pant 01 plant l)iHt a~(gt fl r(ll it pllllIIirU1ry lSillg fur J hours ntGi~ C prIOr tD t 1( plChmll1atmiddot rLlmhll III a II lItmiddot or n Ball amp Jewell mill ~n llltllysis of paldch lzP- nftl~l (oar-( IIindill shows that tlwy ar( about tIlt llllH fOl parbojlP(t awl IJllllluhoileu hrubs I fir 7)
The coalilly gloUllll ample i-- thPll Ildlll forI toUtmiddot at ni C afnr which it ha lllilobtllL(gt output of ~ llllut lII hmiddot- dptPlIIlilwltl by drying submlllpil- at 1110 fot hOtll- TIll 1 IIIIll i lltllt lmiddot0l111d hi a IluninHl mill TIll mo(lel uP(t in thi IIIk i 1I Hu IIIOilll mill as IllUllifill bv Hoss nnt Hartlet ( 1 -[1lt111- with n1ll1l1 pldushyrations ittI lilnbhell b rill HanlIolll V0ll11nHiol1 ElIillllmiddotrill (0 The size lutllihl11 iUlJnole So I ( 111m t ~ II t HUIII Xl) ~ I L~ 111m nnd So 4 lillllU1 11 ttllilhmiddotj 0 r tllP Imiddotlult~ p(lln-It willI t11(e Sll((IIiZtS with )arl)Oiltll awl uil)Jtllboiltd hrlll b lOwl1 in fif1l1fmiddot-- This hows t tnt 1middottttIl ~(I 1 llllll (Up jlllilnl IHlt that
r------~-------r--- ~ --r IHAMMER-MILL SCREEN
O~ NO1
NO2 ---shy U NO 3 ---II
I
bull lL
z
r ------ l 30 ~ gt III
i I Imiddot
i ~ I
I 1 I I
~ 20 I - 1 iii 1[ r 10 ~ ~ ~ I _ ~ I r A bullbull
o bull L-~__~__~~__- ~~ 20 40 60 80 100 40 60 80 100 200
NATIONAL BUREAU OF STANDARDS SIEVES (MESH 1
Yutln I i-tlillltiuli Hf pur id lZt f ~naY1l1 t middotnt r1 lI1 i ~ a hatlltlllI 1IIi11 to 1111 Lx IHtllllH middotIn Lt-anmiddot tIlllunl loy la1 litkh~ omrl t 1) tHul parbuih~ -t B ~ thmiddotfuliufptl ]~lahr thpt tu tt fit t 1 It+gtr-tt1 Jnui~tHn eunttlIt _~rnlitl tl~UP ltakmiddot~~ 10 UddU it~ 1 rtmiddot4~pt~middotK1~r ttakt-middot
bull So 1 gingt- 11 tt-liuin-Iy ltr~pl [lPlItl1tat of iilll 11animiddotImiddot- Eqltrimiddot tIlllll hnnmiddot llOWIl dutr fll llltldllllUU xtlutioH 11pound lnhbll lIl lP-ill frolll IolUlIl ~tlaYlllt tl-IlP by dlt IJwtmiddotlUlmiddot lItlilwd oil Ill 14 - 01
i-mllt 11111- -lwltld hi INd I li~ Ii I TIll lllhtIlttj of Itiu~ So 1 (lltll j thnt 11middotmiddot01middot lttwmiddot to amplil tltt Iollllli tilt art lpdnn ib
IntIIll ll~ i po--ihJI with tI lLllit Ilfltl[lll1t It honld l Plllplw izmiddotl rImt ilt tht h of -allllhmiddot with l lllblPl
~ontlnt of ill PPltllt til lIilll it i tlllt pll--ihl 10 11-middot t(1i Xli L
20 TECHNICAL BULLETIN 920 U S DEPT OF AGRICULlURE
Even with screcn No 2 difficult due to rnbbel tlcrltreCtlltiollS may be ob tl
encountered In thes~ caHeH it iH lWit to parboil the shlub fOL leaf lemonll and finally to dry to about 1 to ~ P(l((llt of tnoiibl1(l pound01 b(~t results jn ~rindillp in tlH hanmHl mill
It iH aclvlsable to provic1l thc hammer mill with a ground wire Hillel the presence of static electric (harges 011 tll(middot partkhH will ealls( Home of these to atlhelc to the inside of tllP (olltailWr OJ lila eallsc OI1l( of till pULticl( to form ngg1(llatls EIIolin lalllpling fl01l1 fhis SOI1I(I mlly be (onsi(h1llbl(middot
A1I10l1g the Holnllts with high boiling point that lIlay Ill IlHld in rubber anal)Hs I1IP Illllhyl n-alllyl ketolle methyl ioblltvl kptOIH diisobutyl (tOIH blltyl tHptate llethyl amyl 1Ittail (middotthyl(middotlllmiddot gly(ol diethvl (middotther and n-bntyl (middotthel (labl( 1) TIHse al( also I(sin 01shy
middotent but th( 1(~illS n1( held ill olution by the rll1)bpl pl(l(ipitant tthanol wll(1 lllbb(r is 1)J(lipitatNI (S(ll tabl(s alldmiddotl) On tIle basishyof the lxpHilllPlltH tll( btsf nil-round lolPlli -rol lS in 111( PIlHPllt method is lt1iisobutyl kPtonc wld(h was not IIltlllllfaltllllmiddotd ltIlling Vodd Yflr n A suitable Sl1lgtstit ute iH llHthyl jolllltyL htolt whi(h is l(porhd as llolltoxit UJ)
Clllos()IY(~ (ethykn( glYlol monopthyl (tIH1) blltyl earlgtitol (di(thyl(ll( gly(ol llIollobutyl (ti1(r)~ and acttonylacetOll( may be used as resins sohrCllts (table ] )
In the earlipr work with (sills analysis cpllosoly( alolle was selcmiddotet(d as a suitable solycnt Aitholllh (ell()~oh( alone is pxc(lllnt its rplllshytiwly gwatlL iscosity 1(I(b to bubbl( formation nft(I (SillS pr((ipi tatioll Thi- increased thp (xperimentnl (LTOI OIl of tltp othll I(sins solpnts tI((tollyla((tolH has the proppry of glpatly lNlulingshydH(OSity 11(11 altld(( 10 othr liquids This sohpnt tlHIeforl wa addp( to ((Uosoh( in slIflici(lJlt tlllIonnl to OPI(0111e the dinieulty On the basis (li~ex)le1inwllts ~ purts oi~ a(donyla((tOlll to I puts of (elloshysoh-f (bolll by olume) as Splldcmiddot(l Thp 01 hel Hoh(nl listed hutyl clLlbitol at l(llst the t((hnieal-g1lld( ploduct uSNl is appal(ntly not as good as eithe of t1w ot1(r two () a (ombinatioll of tlWSt
The SOlVllIts JOI liSt in tumlyzing artifkial lubbel$ hy tlw pr(senf method appllLently (lcllIHl on th(middot kind of llI))(I lIp-ityl (Jxidt is suitable Ol BUlla fi and hutyllthlI for butyllllbbl Tlwse reagents IlLe technical g1lld( Calboll amp CtllUil1t Ch(lllilai (OIP This Hllbjp(( hilS not bepn (XtpllHl(ly illwtigated by till WIit(I
PIIECIIIIJ-
All tlst fOl Ih( adlqlJalY or till IHllipitullb ll(Ollllllentillllll11Sl bl baset] on the plctisioll of tllP final I(snlts oiJtairwd with the methods The )redpittlllts s(1e((( n HpJ (xtcllsi( (xp(IimPlltatioll all HatiH~ factor (Hee fig Hi 111lt1 tabItmiddot (jH) Ext(IIin tllts llllTild Ollt hanmiddot shown that H Hatil-gtflltlOIy [gtIpeipitallt 101 1lIbblI is (li-p(IT(middotnt HzHO (c p reagent nil POll sp gl U-lmiddotJ) ill li-P(l(Put (tinmol by vohmlP liol (tllayul( Ipl-gtinl 1l)-P~ITImiddotllt H)~o ill Hl) by ollln( ii lL satishyfaeto7-y l)lp(ipitunt A solution of 1 palt of H~~o to 1 part of H~() (1-1) iI2So1 nnd abo yarious int(lIlIPdiat( proportions of tlllse suhshystanCPs giyp fait 1(511It8 but with till inlIptl(l ill [h(gt ratio of H~S01
~
bull
bull
bull
bull
bull
RAPID PHOTQlIEfRIC DETEMIlXATIOX OF HtBJER AXD RESIXS 21
to H 20 the )olutioll becollles somewhat vbcou5 and precautioll Il1Ult be taken to ttvoid bubble formation When it i5 poured into tilt Cllvettes
It should be lloted that both of these precipitants have an ftellleshymmiddottion It was found that when XHjOH was used in the rubber preshycipitant in pInt of H~~O~ the readings were -table l)Ut were not reshyproJutihk The lIl of XuOH in pInel of H 2SO j ran nHittble result as a llth H(HY(Pl WIWll til( li-P(l put lthatgtl in lublltl llnalysis or H~O illlP-ius anal)j wn-i uddint(1 thl eharalteliti(s of till liquid with pleeipitated ruhber or resiu in HI~P(ll-ioll n ren1 on the lpNmiddottroshyphotometel m tololinlPtprfollop(1 it lPgnlal lIlll II~ lxplaiHd on pHgP-I (Sl( figs 11 aIlIIl) Tid made it lloible to outain lEPJOshydlHibll tpnlt nntI (onplt1J1(Jttly till JpqnitPIl tlPgJPP of PJPcljoll
IIWIE(TI 1lt COl~101J)
Jtl thp ItJiPl middotxlwlillltnb hefoJ thtmiddot -1l]YIlIt allll pnmiddotdpitallb had lIptll ptoppJly adjutp(l it l fOllll tIuH till llP or a Ploltiw colloid -wll ltIi1)cJ [ttlJmiddotntl- imlIopl tll lmiddotpro]lIibility of the lPlllt JmUkllly ()Ilt 111 U lput lUlU illlihumiddot tOJllPOlUtl tpHd liglyeol teltlut( - llpanlItly IllmiddotlfP(] to lit til I1m t IHflll lImnnmiddott nftlr tlH filial prOIptlllll WtlP dlvPllill1 tlll 11lIlpfit (If thtmiddot [llltlltin lollohl wa Hot 0 natlv I1l(lhmiddotd III rlumiddot Ia- of tmiddot ill tllmiddottJmillaritlu it b [1 hmiddotjlmiddot til IIpoundgt Ir llH1 It liltr ill-llImiddottiT Ina lll ptlPII by it U( in ruhhfl mmly j 11If dtmiddottail fOJ tltt lllllmtlllll If thl plot pet in nlloid ~llntill tltlmiddotlImiddotmiddotlttlatiflll lIOlllllllhtiPI1 are iPllllll page
liTFHFEHliG COIOf
(hi II tht lllail 11111111111 that had til ill -111111 II urklll) om tlH method fot lublJtt tlIlO1 rpir- nlalv~i in plaut llllpll- wa ttl (lilll~ inare tIte (gt1[01 till to tIll ptP-PlHt f xi [aIWIIII- 111 TIlt amount of (olor varip from lUllIt tn -amp ]pplwHlI nlt rhmiddot lt IIf thE Hl(ltllial tllP part of till plllIt -lI11lhmiddot(l tilt hi-tlllY f tlll plaut mtteshyrial ~ub-lltInent to Itlllmiddotnmiddot-rill lliI 1011middotly OrllPI Inlw
In ruhlwr lrtl-i I Iii 1101 au Itmiddot 1Iplll11l by 111[ I--r ratmiddottilt thE -lllll]t with uptoIw or 1middotmiddotlIll-ol - wIdell [llllol- rlll loillriu nutttel autI thtmiddot lpill- Thi- howmiddotvt n(tnll- til lXtla -11gt1 ilt prlJ~edun) In lP-ill ltluay-i nllHufldy tlW[t j 11 1 1IO(PIlln fill the 11shylImya of hlulophyll Hwl rIlI-r middotIOII IHlttlmiddotJ dlH lUtl~ In plltIH withoUt alo aiftIriL till nmiddot ulttrll
111 pllIbIll1l Wi tilmiddotr hId h It-ImiddottHI tht Pltlpll 1 hlitlt lilt tlw tulllWlli tollImiddot uIwltllIIntut -lltUIhorlllllltll 1111 tIll tlettlllliIttwr IIf t 111 lWlrl-Uamiddot of bdt tl11blLlittUhmiddot r [1 tItmiddot preshyj
lipitatifll 1lJ llllllWI atbull 1iI- in III -1nrmiddottIi fHlttalldh nlrillU~ amount rf middotlorilig lIUlttll Iii lhll of ih lltmiddottllllhottohttt~l l~ol()r infrtl Hm II upd 1 rwmiddot tld~middottilmiddottll PlllItlhi~ f it j proYitiltl with tIll lilP--UlY tU(jlIdlllIlml tIltmiddotmiddot lllklllUIlI
EIECTIol OF 1 [EGTH~
-Ptfmiddott ral tracilull ru~lI gtIll fr 1 nllb t ~xtltd 1 lIlt-th vI iobmy1 ketommiddot lWtl rill [ Ixt lttltt ll UttollylaIiIitt1l11I1t~ ~-I itoiu YtHil)u~ typp of ~IHaylllt f i lItmiddot art hraquoil ill fio1ll1 ~l Th~ lp-nlt fill I11oohl uio[1t ttl willlr til tltN- fur rht IUiXtIUt iwliutll
100
22 TECHNICAL BULLErIN 920 U S DEP1
90 bull eo
I shyz 70LLI 0 a LLI a 60
LLI 0 50 z
a ENTIRE 2-MONTH-OLD PLANTS~ 40 b ROOTS AND BRANCHES OF ~ 3-TO 4-YEAR-OLD PLANTSen z WITH LEAVES REMOVED ex 30 a C CURRENT-SEASON GROWTH OF l- )-TO 4-YEAR-OLD PLANTS
20 WITH LEAVES REMOVED
d LEAVES FROM 3-TO 4-VEAR-OLD PLANTS
10 A
0
a Cd 100
b bull
10
80
I-Z 70LLI 0 a LLI 60a
LLI 0 50 z ex I shy 40 ~ en z ltI 30 a I shy
20
10 B
o~__~__~__~~--~--~--~--~----~--~--~ bull350 400 450 500 550 600 650 700 750 BOO 850
WAVE LENGTH lM~)
FJGcm O-Sll((middotlllll tramaniW1IHl (mrpS f(JI (xlmll 11011 n J1ll of jlta)nle tissur ill n 2--m1 Y011111P of (A) Illrthyl ji1I1J1ltsl krtonp 1111(1 (ll) nt(middottQnyla(umiddot tClIc-C(l1osuln a-i
bull
bull
bull
RAPID PHOTOlIElRIC DETEH-UXATroX OF ntBHEIl AXD HEstxs 23
ThE dula Pl(S(l1t(lltl indi(ntp Ihut 101 Illp ulimls llHthyl liohutyl htOlIl (lxtrHts (lI(I r(dolls of Il1Hxi11111III nigtol]gttioll wiH1I all (is-lIb 11 cOllsic1(]((l n1( blhn(11 wn ( ItIl( Its lIO to () I1It~ nlid Ii to Iii mJL
WhllNIS tlw I(gions of 1middottnL(s( light 1lnlllittamp al(l lgtPlW(PIl wan Ipllgtltsnr) to Ii nllt jW) 1I1JL nlld alio Silllill1l 111l1b (n SI(lIlId 101 nc(ton ]altmiddot(fmiddotollp-(llloolp ~ pxt Ill of 11a 1111 t illl TIl( (1101 du( to lolo ill tlw litlltitl a 1Il1 lullll(I tH lPill- hanmiddot bpllI PI(_ ipitated ma he 1((I1((d to fltI ynbhing poillt II ph( illg OJ illshylmiddotJall(( WIWp balld nhm ()) IIIJ1bullbull[1I111 lxjlPIitllll1b Illln -h()1 that Ih( lIIot uilahl( WHYI lHlIJ fOI 1-1 ill 1l11J1l(I HIH11Pill- illllllrsi i-in till IlPighl)()lllll()(l of ~llIl1lt bull
bull UIlIilHlIy of n typhn] lXPllillllllt to )10 l1iP(tiP ((JIlllo( of (ItOIS dul to lOIOl in 1llblnI Hnd Iill xtnumiddott 11(11 IIIIolp t jUl i p1llelll((l ill tub]lL Till llhlllt- 1tpIO]II Hnd ((llll~()h whit-h UI(I ](]Hllilltl n 1I01lllIhb1 01(111 lxt 11111 IIll 1llll)1 nmtp[in I and )(middotills Tid IIlnkl it poiblp nftlI tlIp uplll1tillll or tlll o1PIl( (0 [niH lip 1Iidl1p~ of lI111 11111(( ill lit ll11l1)[1 (llnlIb nlld Ihll
Sl(ll n ol1lliOI with tllP olnl IJllt illiollt HIl Iltlllll llllI (Ill ltllthpl prpipitnnt j Ihll1 nddld OUI ha a lIilPt lP( of till lIiciPlw of WH( lllIgth 7) lUI- ill llilllillatiu (nnl till tll Ixtll1I101l ()lll~
Tuu tmiddot-Elilll IJl flrldillY 11-1111 lrlllI IjfJI til islII 1 1(1 ([rllt IIIIIJIlIr JiIlIt~ if 1Il( Ihll 111111 k til I III Ilrln I 1Intd tf 11111 JiSf fill I I II I tIII Ilf Iilltl 1f1JlIIillII1f I Till 1[ 1 IId 1 (I (middotIt 11111 (I1I1iI1 1lf1IWtlfJlIIllfflr p middottrllhIJ11 II J III 7IImiddotIa 111 111 lilt jJIp 111 wilTII
t~t tnVIli~ ~nn r kn t~ i tmiddot ~~l Jr 1middotmt ltlTt
HmiddotOtt ~I~ lin t I ~ 1 t~~l ~qrmiddotthtmiddotrtwb
Hult-middottltlru t T Hw ullut rHtt~ r II I ~ PH~lllt
A~tmiddottHHjmiddott~rjd rl ~gtllh 1 tn~th~ ~ ~ middotI lt~ b w bull hmiddotth~ 1i~lIhun 1 Ii tnl Illd1 -11lt1(11i lullI lUI tJl ll~ t1~11n( I Ihan1li flfttIJir Ult I Uuhtltt ahuul l(hmiddottHmiddot~t trv r fti HIt lftbyl tlonhUt)1 k_hIl( 2 m~ fmiddotf tuhlHmiddotr In mlth~ llmiddotlf- 1 t r
t r_~ t j
Arhlitlltd ~llIIDHl NcWitn1 ( Ar-(lt()nc~middotttrrtrt ritJJI~ -Iu nllJtl4-middotr
ACtmiddottflnp fmiddotxtrn( ~ T-P511ftf tn mtmiddotth~ 1 ~difmiddotut~ kdn 2 nltt ulruhhtr in Un-tIl lltbu )J~IYt
rUth(Hl~hltlft HhubU
Illlh(I(t tttUtUt hUbtl til J ~jlitl(J Hilllll trtIIImiddotjtl1ll
(UShl I ~tlO wHllolH rulh r (middot1111$0]( J~rru t t )lthyl 15bullbull1middot1101 klll1l
Ili( UHUicbcul ~((i1rUtl ~ulu1iin 1middot lIUIll Ilti lrllltlllt I Ruhhr llt1thuI r1 -1 Irld
ltlt1111Sh 2 nuz f)rruhl~rm nlith~l tu- h f nt nil~middothgt(H] tlrlftmiddot 9lUtirtl middot1 1
rlcltfl( H(l dnllltml it
(IISllhH~rI( Iultruhtr CII05 1v ltTlft I 2 UI~r ublwr In llldh I hlt~1 11) lgtjdvr(llsl~9rlltmiddot middotlmin ~ I~ gt AIHItilltl no IrttipHallr iI
~ Bbnk 10ol m(thyl i~tmiddotut~i kdHn H 1 m1 j~~ l1rH-t lt~tlfltmiddotn sf n it ll HltlMjftr~nol O2~mlJ ~U~1o-ulp ti~tW -xtra~middotl(lt1 ltt 411 ml bull ie f Ct- kft rt t~ tirattJ middott ill r u l1kn ttJt
in metltl isobutyl kNqnf nn~i mljp ur tmiddotmiddot ~oml ~urr tttl i t w ltJj1JH kt 4t 3 nlank 1 mL((l1t~rthmiddot(middot mI mttr~ ~but a kmiddot tmiddotc d 11 ~ gtli~b~ hifIAft- fl~ lL lnti 149
ml8(dlfilll BO bull 02 gm guayule U$Stl(middot xUlClt-l tf(h tft wI n nmiddotmiddotmiddotlgt 1 lznt on tmiddot ~Jt r~1 ~~u~~ H~ iI~ thT
24 l$CHNlQAL BULLETlN l20l S DJltJPT OF AGHl(CLlOHJltJ
In table a is pl(sentc(l such c1il((t edlt1tIHC showing that thc (0101 Ixtrnetccl from guaYIIle tisslIe wit h II(P(OIl( n nd (pl1oso[yc is cll(div(ly sCIe(nec1 out by the s(lp(tion or wnw length )0 miL Oil t1w SI)((IOshyphotonwtpl This tnb]p all-HI ihos thai thl Juhlwl altl(l((1 (nn IJl quall shytitntivcly 1(I(()(Ipltl in tIlt PI(ilIH( or Ih (o]OIplnwPIials and Illsins and tlmt Iuhb(l WtlS nppnlllltly 1I0t (xtltI(((1 110111 11l glll1I1l lisslIt b~ tlHSP SOhlllts Thls( ((suIts ginmiddot (OliIHillg (idJt(( that t Iw IISI of waYl llngth i)ll 1Il) OIl till SppdTophot OIllltPI ii t hl 1101(1 p(oshy(ellule in photolllliTie IlIlalysis of luhhlI OJ l(sin-
SELEGTIO- OF )IOiOCUHO)IAIIC ItIIm ((1111110
On th( basis of th( IPHIlb shoWIl in tabl(l 1 al hlllpls (1( IIln(lp to SPCtl lC the PIO]Wl 11101lO(lIOl1ln til Ii ltlJ ((lIllIJi nIl ions 10 llIiOlS (oIOlimet(Is 111(gt 7W-Ill~ filtpl flllnhwd 101 til( I1~lI1l photoshyplpct1i( (o]oriJl1ltll fol which Ill( (hlll(IlIiitit~ oj t hl Ilda he light ilUIlBlIIhiSioll (t) elll nn -hO11 ill fig1lle 10 iws satlsfa(lolY IPshysultl 111( iiO-mL HitlI olllhintioll 101 whkh ttp (middotIatinmiddot light tlnnsmission (ullmiddotis a 1-0 showlI ill figllll (I is -nthdnlto1 hut this is not stnlHlnld NtllipmPlli
Up to fhl PlPHllt lIS(middotflll pound11((1 (ulllbinntions jn lltl iOO-I11L Iunge hayc nol bllll SlClIlld 101 lhp Klpt 1-1I1l1I11PISOIl (olOlinwtll bu fnltlwl nttCl1lpti 1( )(illg IlIHd
TJIpound OF ST~lmW AFTEH HIIJ1EII Oil HHSIS rlll~CIIITTI(J
~ considl1ltiol1 of ttp lillll of Inlllling af((1 plpeipital ion of 111gt)(1
01 l(sinSTlOIll ollltionis impoltant J(jl~ thC1HI(Plltngp of light IInIlSshy
11 rshy10 f shy
09 f shy ~750 Mil- DOMINANTI
~ 08 cshy I WAVE LENGTH z
I III III i O7 - I III
~06 - 05 shyw
a
Igti= 04 - 720 Mp DOMINANT ct WAVE LENGTH- ~ 03shy
02 f shy
01 t shy 1)O~~~gt~- J 600 700 800 900
WAVE LENGTH (Mp
bull
bull
bullFIGlRt IO- COJllPIUlItiw ~IW(middottltll tlnIlRlllii-lion (II (IllP( 101 1i11(1 olllhinulloll
with dominllnl Il(lllllgths at 720 and 7iO lUi
bull
bull
bull
HAPlD PHQTQlfE1IUC JjETER~lINATION OF Rnmrm AND HEtiINi 25
mitted (spertrophotoll1eleL lCuding-) Ol light (1 (tClcrl (phOlOshyJluol01l1et(L lcndillg~) i~ StlhjNl to (hangl
]fjt~l1le 11 and l~ show that ill til( (asc ot tJaugtIllitteltllight llJHC th~ (x[llliHlllIlnl (oIHlitiOllS tllpl j lilst n dtlln-e ill Pll~(lltngl or UllllslllittnlH( follrnY(l by It ptJiml of lClntin stability with only sliuht (1111 tHn- a f(Pl a lIt1ll1btJ of minutes The light t UIllllitblllll t l(1 ill(Iln~(s This lIIay IJP llllllJltlli7P(ll1 ffl II ow 1Ilt )( f(( darI oliIII tIIlIlNlIlitt(IIIlfJIIlh (iditilIiid Ilil1 pllIipintnl )uoshyIn Of ( 8inx in (~f1( I~iUII i~ Ild stahl I 11 itlll If 1inl nh prlshyilli(ioll of 11l1d(1 II IJIX f) jllIli II (fJJltfiIIlilty slllMI IIriot 1) IIIPldUnl1i tll(I1I rllltltilJl oj tJi~ Jlt jiot IUN ilUf Jxl1 will tIt( tOWI IItlllilil I 1llIlllblJIol I ill I~11l11111 d ill till ifjuids JjOI scnttplltl light 011 till phololltHJIOIl1lttl till dilPCt ion 01 elangl b tlw IPrfIi (If that illrli(atPll rOl tlulll1Jittp(lliuht It Itlll b( llluliJr I-(Pll that if l(middotndlnJ- IIIP mad n itl I t lIP ~()ll1d()lb lpalll this pllioJ of nmiddotlatirp tuigtility tllP llLot tIOllt thi Olll(P (nil bl IPdUCld to tIl lltini III 11 Ill TIll l~adiltg (illH~ bbll Oil tlHl datn rUl lublwls and llsinlt Illl ginll ill tnhh
50 r----------------------------------------------- f shyZ
~ 40 ~----~W~A~V~E~LE~N~G~T~H~7~5~0~M~P~~~~ ~ --------------------=-=-= ~ 30 f- WAVE LENGTH 540 M~ _z _____ ___ -=- __ _ ~ ------shyt ~_=---=-=--I GUAYULEIII 20 -Z HEVEA ltt II KOK-SAGHYZ f shy
4 6 8 10 12 14 (6 18 20 22 24 26 28 30 STANDING TIME (MINUTES)
FIlirtn 11 Emmiddot of wav hll~rh Il li~ltr tlall~lIIit1alHl aftI IUIlItHt -Imlli lug 111m for guaynh llmiddotn 011111 middotiolIlJh~z 1111111 llijlitul1 flolll 1lHlh~ll1Jllryl k11II11l ~(lilltlll h~ lwitlitll 111Inu1 111l~1It1 2)1111 o1U11111 (Helillins on (illllun tlunhll IlIIJlllw]ntllW111 lutl(I[lholtllllltlt with ijUjt Wlnl IHI Ilf1 I
11 EFFEGT OF Hbli 1 -()JXT10~
Tilt lnblwl ~()h(llh pxtnl( till IPillgt ubo It 1m nllu1- bellt -~atea thut ~lll 11-111- tUP olnbhmiddot ill middottIIlIlOl ~1It tlWIIJI( my U)t PIl (tlIHatcl WIth tl1l lullh(t I tahle lJ 1hln 1- -1111 tIll (llllstlOll of nny p()~iblt tITptt of XtIIl11 diflp]lws ill ((JlllPllttUliollS of 1l-in lil lolutioll alollJ with till 1lIltbpl TIU data ill wbh +ho on tIl( hn~is of (olorilllPill ladillU thaI tll( IIUOIl1t of lnbbll Plllipirntld 110111 Ilwthyl olnlld kptOlll olntioll IJ 1li-jHlllnt 1l)04 in 1-llltlIllt ethallol)- not amlll hy thl llllNlI(l of llvin aU1ouut of llins inolution bull
-----
26 rECHNICAL BULLEfiN 920 U S DEPl OF AGRICULlUHE
100
90
80(I) C)
z Ci 70 UI a 0 60 a ~ UI ~ 500 ~ 0 I Il 40
30
A 20
0
100
90
(I) 80 C)
z Ci 70 UI a 0
60a ~ UI E 0 50 ~ 0 I Il
4-0
30
B 20
0
--
--shy ---shy---
2 4 6 6 10 12 14 16
---shy= ~ ~ shy
-
2
025 05
10
15
20
25 -30
35 40
SO
-60
=70 80
16 20 2224 26 26 30
OS
- 10
IS
20
2S
30
35 40
-50
-60 -70 -80
bull MGPE 25-ML
VOLUME
bull
MGPER 25-ML VOLUME
Florm 12-EtTld (If till1l or Slllldill~ 011 light transmittallce (01 (A) gUllyulc lnUIl(I plccipitllitd frOIll llltt h~l isobutyl Ielollt solution Ily neidilic(l ethanul bull null (B) gUllyule ll~illii pre(ipitated flom aeltoll~lllcetOlll-Cl])osolY( 3-7 solushy11011 by H(illilip(i l1U (HPlldillg~ nt -lIlillult Ifllpluls 011 Evelyn photoelectric colorimellr with jU-lllp tlllll alit U-1I11 npN(lle spp also table 2)
bull
bull
RAPID PI-IOlOMEllUC DElEnMINAlION OF RUBBER AND RESINS 27
TADIbullbull ] 4-ReZation of amiddotmount of middottbber pleeipitate(Z Oln metltlIL isobutyl ketone 80lutions by OS-pereent H 2SO in 95-pere(lIIt ethanol to umollnt of resin8 udde(l U8 indivute(Z by colorimetrio readinU8
(Rubber ami resins cnlculntcd on bnsis of amounts in 5middotml ullquuts of extract from 02 gm of tissue in a 2fllll olumo( bull
Hubucl r~cocrell whcll rcsins nddcd as IndIcated Htbbor al1dcd (pllcollt) ---shy
__________bull_________ ~_12rpcrc~15011crccllt 7511crccnt IOOpcrcent
PerCtllt ercellt Percellt Percellt Percent o o o o o) 50 250 263 252 25000 500 500 500 500 700 750 750 751 749
1200 1250 1250 1250 1250
EXTRACTION TEMPEHATURE AND TIME
Typical experiments to detllmine the time required to secure maxishymum extmction of rubber und ltsills at 115deg U Ilre sUlIlmarized in figule 13 the solvents used-methyl isobutyl ketone for rubber anrl Ilcetonylacetone-cellosolve 3-7 for resins extraction-are very eflicicnt since under the conditions indicttted maximum values were secured after 30 minutes of ext1llction The most eflicient liquid for the bath (lig 1) used in extrtlcting rubber or resins is ~ high-grade cylinder oil (S A E ~O) The sand bath and such liquids as glycerol have proved unsatisfactory
RUBBER AND RESINS STANDARDS
According to the National BULeau of Standards 1-_ lhclc Is no gellcrnlly recoglllz(d standard lIIutcrlul [ior II rubber standard] The rubber hydroCllrbon ill llifferent samples of conmlcrciul smoked sheet or pale crepe from heclI pluntlltions nries from l~ 10 04 llercent of the totul nutletmiddot the most 11Ioruble conditions Of preparation
McPherson () has described a procedure for the pLeparation of pure heve~ (Hevea brasiliensis (H B K) MueH Arg) rubber from crude rubber or latex In the absence howevcr of ~ generally recogshyn12ed stalldard for rubber hydlQcllrbon [caoutchouc (CnHUs) xJ the standard adopted was that of the relnthely pure product secured from gunyule tissue txtractiotl nccording to the Spence-CaldweU method (5) or the motlified PIOCCdUlU of Hohnes lind Haasis (p 2) The details for constructing the calibration CULes are given on page 10 Standard rubber samples apparenl-]y can be stored for a long timc under the conditions des(libed on page 10 The duplicate colorimetric lendings for glULyule rubber newly extracted by the modified SpenceshyCaldwell method were ()J2 ench as compared with US) each for the sample extracted by the same method but stored 1 years In each case colorimeter rcadinllS were made on mixtures containing 2 mg of rubber in It 25-1111 Yolume
The selection of tt suitable standurd for guayule resins presents some dilliculties Tll(~ acetone extract of gUllyult estimated on (l gravishymetric busis~ for instance proved to be variable depending on the type of tissue sampled or season of sumpling because such fractions as
COllllllunlcntion dul(lt1 Octohtr 22 11H3
28 QECHNICAL BULLEQIN 920 U S DEPT OF AGRICTTIIlURE
16~==========================115 shy
14 bulli= 13 z ~ 12
ffi II Q
10 c w 9a w
8gto () 7w a
6a w
5en III ) 4 a
3
2
A 00 5 10 20 30 60 90
14~------------------------------------------- bull13
i= 12 z w II ()
a 10 w Q
9 c w 8 a w 7gt o () 6 w a 5 If)
z 4 If)
w 3 a
2
o+B~~__~__~____________~__________~ 5 10 20 30 60 90
HEATING TIME (111 NUTES)
lllGUltE 13-lDffect of time o( lICntillg O2-gm samples of gunynle tissue with solYlIt nt llfio C on lo(OVl)ry of lllhlJer alld 1Isim Lt HlIhblL extracted with methyl isohntyllwtone B resins Cxtll1cted with aCftonyla(etonc-cellosolve 3-7 bull
chlorophyll are weighed along with the resins in the acetone extruct but are not estimated by the present photometric method (fig 0) 1he use of a diffeJent stanclttrd waS therefore indicated
bull
bull
bull
RAPID PHOTOMETRIC DETERMINATION OF HUBBIm AND HESINS 29
The resins standard selected is based on n relatively pure source of resins the rcsinous exudnte 011 the stems of guuyule plants IJldimishynary expeliments with the resi nouS cxuclate from diffcrellt gllayu Ie strains of various ages indicatc nHlt there is little YaLiation in this subshystance on the basis of Colorimct(r readings 011 2-mg aliqllots of 01shypercent solution in It 2i-ml volume (tabl( li) Expelilll(lnts have shown that the air-dried (xuclate contains 3RtOH p(Ic(nt of -volatile matter This material is l(latiyt~ly stablp ill (OlllpoBition and is npshypurpntly on ly slight ly hygroBcopic as shoWIl ill Ia bl(1 1 Tlrp Ipsinolls exudate may be jJleplpd in two wayi-i fl liSP as a stallClHld-(l) the clpan exudate is clripd iol Ghouls at ()1deg C at W indlPs of a(lIum Hnd aftclbCinOglOund ill a molfalis 1)I(spI((I intn airtight COllilinel OL
(2) tllP Cx7lclate is clissolllt1 ill a(lhllll and filtplpd PlactieaJlyall of the acetm1l is thpn lYapolntwl olt OPI a stlam or atCt hath and Ow residue is dripd ground an(( PI(sPIld as ill tllp fin lllethocl Tlwse two prepalHtlolls a1( (ompalpd in ta hlp ) 111( (((tails fOl ~t()lil1g the resins standald and (onstlllcting the calibration CUITPS alc given Oil page ]2
lAIIIg fi-CUIIIllrsoi (lJ lIr-dr(1I IIIIi 1((11 II II-()I-tr((l l(sil~ 11111111(8 of I II 1111Ie
[Colorimetric rrndill~s 011 1~I11 phulll(Iclrie eolorillJct[lr with i~()middotmll (100- to iiOIIIIl) fillcr [lnd 5-1111 lIperture preeipitantl part ofO5middotPIrctllt 10 to 5 paris of IIOj
nupliclllc(oloritwt([
nIl(lin~s (hIlSlcAg~ ofSlmillXo JrNliltlCllt of fPsiJI$ L1Xtlrlntp on 2 IIIg ofplanls fllsins (XIHIIlt~Jwr 25-1111 vol
tII1(1) 1
leflTs Various _ bull ____ bullbullbullbull 3-9 Colll)Josiltrlairmiddotltlricfl bullbullbull nf)2 002
])0____ bullbullbull _bull __ _ bullbull ~-l Composilld (ri d at n5 C in aUmiddotimh lWUUllJ for l (jOuj(ja hours])0______ bullbullbull __ bull ___ bull 3-0 COJIlpositld disso]NI in neptolll f1l1erNl fl(lf()ll( GGO i(jO (Ivaporntld olT OV(1r Stpl1l11 halh TesidlH drl(ld I1t fi5deg ( ill anmiddotinch VIl(Unlll for 0 houlS bull
middot106 __ bullbull _ Jir~c1rild_~_~_ _~_ ~_~ _ ~ ____ _ __ _ OUu GOifina_~ ~ _ ~~_~ ___ _ _fln~ ~~ ~ ___ ~ __ 6(imiddotI tiliA H)[_ ltlu bullbull i18 tisSflOabullbullbullbull__ bullbullbullbullbullbullbullbull lt10bullbullbull _ tillO llitO406__ bullbull __ bullbull __ bull __ __ lt10_ Utl2 fon591_ fo__ bull liGa oOa 406bullbull _ __ lt10bullbullbull_ li5S OM
j Ph( vnluls in Uw Inst COIUIIlIl indieatp thnt gunyulp fesinous (IIHlnt( wlwtlwr dfircl hi Yn(tlLJ1l1 wilh L~ perc(nt loss of volntllt wutl pr or tWl c1rild giVPd npproxil1lnh1ly t Iw snllw colorinwtCr rNHiing- 011 till busis of aliquot~ cOlllniuiug 2 IJI~ of flsillS lXIHlntp l)tIf 25-mI volultl( Ihil- illdicate~ thl11 Uw UITW IJ1flS~ of olnshytile mntl(f prt~(iJlitnt(d gins npproxilllntlly Uw $1II1l (oiOfirnl1tlf ftudiTlJs ns tho ftsidtw A pnlill1jllaf~middot (XIlltrinllnt indicutls thlli th VUllltill muller l(lIlSists of thl Ilrplne oil fmcl ion I5-(1Il gtnplls or rlsitlOtlS (lxudntll gnvll by stPll1U distillation nn Uefllgl of 011111 of jl(lfPlIW oil with npproximHte tilllsity (If OHIi lind lhus rrprlsll1ll( IlPIJroximllt(I~ 01 Jerccllt Of t he original weight 1hls lllrClnlage complrcs wllh 38 llltrC(ntlost by drvinI( in IICllnllJ
aSplusmnUH perceilt or orlginlll weightlosl
The wailnble illfolJllntioll on tlH (ow-JitlPllts of the gunYllle r(~shyillOllS exudate alld tl1( HeetOlIP ext act of gaylp ti~slw is sllIllmarized in this paragraph lYalttI (u) alld also Hangcn-Slllit lind his coworkshyers 16 reported that 20 percent of the resinolls exudate from gUltyulc stems is parthenyl cinnamaie (CHuOH=CHC020 11JI2r) Steam disshy
15 (OIlIJIIIIUicatioll flom A T Haai(II~l11it llId (0011(11 Calif0111 ill Tnfiitnte of Tccllllology Past(IlIJI Jhps( wOlken al Htud~ing the COTlHlitlllllts of the acetone extract and other conlltituellis of guuyule
30 TECHNICAL BULLETIN 920 U S DEPT OF AGRICULTURE
tillation of similar resinous exudate in the writers laborntory has yielded approximately 4 percent of the whole as the telmiddotpene oir fracshytion Haagen-Smit and his eoorktrs nportec1 thttt about 25 percent of the acetone extract from guayule branches is parthenyl cinnamate and 6 percent of the bark (ltortpamp-phlotm) extraet is parthenyl cinshynamate These workers fm-thcI reported that 25 lwletnt of the nc(shytone extract frolll bLllllches is a compound with the tlI1pilicaL formula CBoH400a 1 percent is a compound llwltillg at 2P to 2T5deg C and 1 percent of the extract from the ]eav(s is tl (olllpoulld nwlting at 100
to 1710 1Valtei (6) reported that 3 to -l perc(nt of the tI(eton( txtract
of leaves and flowering StPIllS of guayulc eonsists of waxlike substances soluble in olgallic soln~nts but insoluble in at(l and (on(ent1llted H 2S04 The flactions mentioned on the basis of (onHLTutle esti shymates of amoullts actually isolated tlecoullted for about H ptIcent of the totalncetollt~ so]ubles extracttd from tll( guuYllle 11 rub The other constituents ltlilaill to be i(](ntifi(d
RUBBER AND RESINS CALIBHATION CVHES
Typical culibndioll Clllves iol Iuhbpl and I(sins bas(d 011 (ldtLminttshytions made nccoLdillg to the plocCdmC outlin(d 011 pages middotb to 1G arc shown in figulPS 5 and 1+ The spCdlopliotoll1lttL en (OIOIjlllctCI readings are plottCd on s(lIlilogalitllllliC pappi ag-ail1st (Il 11IbblI (011shy
100 ~ 90
80 ~ 70 ~
z 1amp1 0 II 1amp1 IL
1amp1 0 Z
60
50
40 ~ltI 30 ~ en z ~ ltI II ~ 20 C) ~ oJ
10 o 2 3 4 5 6 7 8 9 10
RU8BER IN 25-ML VOLUME (MG)
bull
bull
bull FI(lURE 14--Ctlihration curve fotmiddot gllftYlIlc lubb01 (Hct(lings Oil COIPIIHlII tlOl1hl(
monochromator SlCClrophotolllet(r with 7fiO-11IL Illtel alld Hllp Wll ( IHlll()
bull
bull
bull
RAPID PHOTOMETRIC DETE~MINATION OF RUBBER AND RESINS 3]
centrations From a casual inspection of these CUlTes it would appeltr that Beers law does not hold Actual tests indicitted that Beers law was applicable only within a narrow range in the upper portion of the curves The analyticlil results on the basis of photornetric readings nre therefore calculated by direct reference to calibration curves or from reference tables of equivalent values bllscd on the cnlibllltion curves
Calibration curves for kok-saghyz alld heyea lI11tulltl rubbers and Buna S (GR-S Chem Gum IV Goodyear) and butyl (GR-I Standshyard Oil Co Protoc) sYJlthetic rubbers are hOWllil1 figure 15 The samples of kok-saghyz rubber were furnished by the Diyision of Rubshy
100
90 ~I) ()
z 0
1amp1 a
~ a
80
70
60
s 1amp1 ~ ~ 0 ~ KOj-SAGHYZ 0 l Il
50
HEVEA~ ~
40
100
90
~ 0 80z Q 70a Co)
a 60 ~ 0 0 x 50Il
40 ~----~~----~------~------~------~--~ o 2 3 4 5
RUBBER IN 25-ML VOLUME(MG)
FmUIlE 15-CaJiblation curves fOl kok-snghyz h(YCII Bunn S lind butyl rubb~ls (Readings on gy((yn photoelectric colorimeter with i20-lIIp filtpl and 6-ml aperture)
32 TECHNICAl BUIJLETIN [)20) 1 S DEP1 OF AGrnCUIlfURE
Iwt Plant JIl(I~t ignlioll of thi BlII(un and (1( l))(parcd according to 11( SPltI1((-Culd (]] (6) PIO(((lllll Hlpt pal( CLPPe was (xtmch(L with acetone blI()Ieit W 1I(gt(11l a ttnlldal(l
SEXSlllVllY Ol~ llETJIonS
By lip pIO((l(II11P olltlillP(l 011 ]Hlg( +n Iowa (lOOl IIIg (11 1111i(l0shygmm (gHlllllla) of 1hblI ill a 2)1111 yoltll1ll (all )(gt dltpltld Oil tltl Col(man (lohlP mOIlWhlOl1lHlOl l-I)((t 101 l1lOt 0111 ci( I ill1ilnlly 001 mg of Iublwr ill a 2J-1ll1 n]ulllP Illay bl Ilad Oil till EnI)1I photoshyllectlie (O]oLillllt(I Thll ya lllll- 011 tilt IHl-i- (J I (xl ad iOI1 fmlll 02 gill of til-lI tH(JI(lillg to tllP -lllndal(l jll()(pdull 1(PIPStlIt IlO()2J tlnd 002) P(IT(lIt of llIbl1ll IPI)(((inly bull1t1lollgh -lI1t low allils can be d((d(middot(1 il lIoullt1 Ill IPtllizpd thnt till PIIOl ill PlI(Plltng( or tll( al110unt dltlIllIilll(J i ltlatlpl high ill tili PIY lo Itlllgl 111 aetllllllladie(middot Ill( lopl lillliL 111)(1(1 lIw (ollllil ions of tlil ]lI()(lltlIIIl u ol1tlinpd ipt at l11 11I1 or 1111gt11(1 illt i-1ll1 Ollllll IlPIPltPlltillg 01 p(gtl(pnt of JllUiJtL un tlll 1Hli or (xlla ion rlOI11 II rlll of tisSIll
EIlIlOH COSIIlIHIIO
In Oldpl to H(IIp ill )1lHtPltt pl((iioll illlpIi1I- it i lH((SSHI to slnlldHIdiz(i rigidly 111( Pl()((dlll( 0 illdi(ntpd Oil pnglt- - to J( If lids i dOlH tlip lXIHlinwnlal PIIll is t(middotdllld 10 n ndninlllill
Illlt pl(iioll of (hI ]lIPPllt 1IHllwd Oil til basi of ]llllP llIllJt1 alld Ipsinssollltions call hI jlldgl(J 110111 figllll Hi lileh lio- til HPIlIgl d(intioll oft -illgIP lI1lnSIlIlIIIlnt in lHi((lltagl of Ill( alllOllllt 01 Illhshy1)() 01 lpsins d((PI1I1 iJlld TIl( (1101 PlI(Plltaglt H1( gi (1 101 OJ) to
RUBBER IN 25-ML VOLUMEMG) 004 01 02 03 04
i= I I IZCtOW
fbA ICtU CtCt WW a
01 02 03 04 05 06 07 08 09 100 = RUBBER (PERCENT)
RUBBER IN 25-ML VOLUME (MG) 10 20 30
~ I CtZ
bBOw Ctu CtCt Ww o I~
010 50 100 150 200 250 RUBBER (PERCENT)
RESINS IN 25-ML VOLUME(MG) 10__ __3-0_ 40 50 60 70 60 90 100--_-- 2_-0
Ct~ -r- 1 I OZ
WCt UCt b C wCtW
a o I I 150 250
RESINS (PERCENT) o 10 50 100 200
bllI 1tI W-Yllnl dtd1 ioll I I 11l1 11IlI11 1(111(11 1 III Plll- IlIIIlol1 01 IIim~
bull
bull
bull solution Il basis J o golH of tiSSII (JlILCl-nt (11(11) for (~I) (l)1 til O 1I1
of luhllpl lin 1 III I (I Ill of lUhlJPl nllll laquo I J to 111 nlg of IlSlllgt (Itllillgs on ]iYllyu pllolwh-llrk CO[IJlilll(-(PI with nOHIP Iiltlr lIntl U-lIll allcrture)
RAPID PHOTOlJElRIC DELEHlllNAllON Cn HUBBER AND H1~SINS 33
10 mg of rubber anel1 to 10 mg of resins in a gJ-m1 yolumC For
bull
bull
bull
comparative ptuposes the leslllts arc also calculated on the basis oJvershycentage rubber OL tltsills in 02 gllI of tissul As WOlllL be expcet(d the error increases sOIlHgthlf for 1(lali nmiddotly low COlHell t1llf iOlls oj rllbbeL or resins The curves in figure 1(j s1l0 that ill til(gt Illlge Ol to 10 pCrshyeent of lubber the elTOI rangts Jroll1 abollt Ll to II) ]IlC(lIt abo(~ this mlllc tIlt (ITOl d(((ts(s to (ollsidlItbly ltmiddotss (han 1 1lICPllt of tlH mllollnt ltl((Lmill(d Hil1lilally in tlH (lISl of l(sins analysis (fig 10) the ltLTor is (onsit1eIubly INS than 1 PlLllnt ill (he lallgp of 11 t~) ~() penPII t
In nil ([lSl of lllhblI alld (sins lx(Inltpd tIOIl1 (issups Ol addcltl to tisslle lxtlads (s(( tabhmiddots (i H) illyolillg ll01P o(lllntiolls the eLI01
is hig]wl thun that indilHtld in figllll ((j Im pUIl Ill )])p I tllllllsins solutlOII
COlllUCIIOXFOH IXSOLl-IlLl~ Ilgsqgt(Jg
111 th( Jllo(pdulP ollllillPd 011 paw I till illsolllhll isSII Ipidll( tflpl (xttlw(ioll is (Ptill tlw lIask l(lll till xtlct i l1wdp up to yoltlllH It is not rOllPllipnt (0 IPt()PI qWlIltitati(Ir III(lw[olH a 11(1 pllooll extlnlfs of guuyull I is-lll alll thl1l main t11l111 up (0 YOIUllllmiddot bpCaUHI sllch all additiollal stltp wottld]) tillll-C(JllS11ll1illg Th( Iogiea nll(gtIshynntin is to mnkp tltl lXtlUCt Llld Ipsidup lip to OllillH in till original flask andi llPSStllY 10 llwlno tl OIIpdioll wlHIl (allIlnting [hc llshy
Hults f(JI [hl oll111lC displupd hy till ins()lllbh llsidll( III it l)picat (IXpednHllt (ollsisting of Jhp lppJiea(iolls if was Iollnd llftt at ~iiO ( 02 gill 01 Iuhhll pillS IPill-fl(( lisslI(gt (lollpdll fot llwistUlC ou basis of dlyillp ut lOW 101 ) llOlll-j (lbp(ld only t~ llllUll voiul11P of OOk7D~- OO(lOO(i Ill of lllthyl bolnl(yl 1lIOll( (lplhlli(al-t(Tnltle sp gl () Ii I ll(Hli (j at ~)) -gtitllP tl1(gt 1It101111( () r t is-lIl xt Iadld j sl1lall til( PlIOI dul to Ill(gt insoll1blp Ip~idll is slllall III [0111 ill( wOtk it (all lJp diIpgal(ll(l
]hcon~lIY OF HllIllgl AiO HESIS AIH)gl) TO EXTlIACI OP
GlYlLE TISSlg
Tnl)ll G L(IHpslntillp (ypi(nl llld(~ SllOS (hat all a plngl of HIOK PlI((nt ot lltl pltl( Ilhl)(l acldpd to tllP Itll h iolJut1 InmiddottcJllP xhnet
of guayulp tiSI1( WllS 1l((PllIl Tlli nllintioll flOlll (olllplpU I((OYshy
PIY i within flll pxp(IiIlHuttllIIOI ~illli]llly fnbll Ii llows thn 1111 llYlIUgl of 1O(1~ ])(I(Pllt of gllllYllII 1(-i1l- add(d to II( (pllosol( (xshytrae of IUllY]l t i~HI Is 1l(oPIPI
THl~ (~ Hf (Off Ill of 1111)( J OJ I~il~ lItfI(( In ~(JI1IJk~ Ilf (111 [lI1Il fI2 lIII
0 tlUfllllit i~~I1
Instrument
---- ----~---- bull shy 1(1
Colemun ruono~ltrOUlllt()r 2t) II sJl~ctroJlhOL()lIIeter with 2tJ I iflllllI wnclength Fetting 21 II nntl 0-1111 WU HI hUJl(L _ L U
Ill 7Evolyn photo~lcclrie (olor JU [ imctcr with iO-llIl filler IV (I
H1 0 t I I
llImiddot lUn WII 1011 HIO Wn mil lUulon
10 JIg1111 IUI ml lUl anh Io aLn 111)_I ) III li lU It 2) deg wn2SU DD
Irl JIll II IIr II US II
1110(1 lULa lUI IlK) IJ WU
I( llI Htl tNI 1(111 2tlNI HI 0 221) lllil t2S 0 1~ 10 1~13
In (I 2117 I
10U 1l(J ~ 4 _H_j ___
9middotJIlJ5 10115 10 00 lUU5 flUU 4li (tl03 9(11)
leIlKl 1l~)5 lOOU l1KIr JOIS un 003 OIl Ii
34 lECHNlCAL BULLErIN 920 U S DEPT OF AGRICULlURE
COMPARISON OF PHOTOMETRIC A1D MODJIoIED SPENCE-CALDWfLL METHODS OF RUBBER ANALYSIS
Guayule samples were analyzed by the photQ111etIic method and by bull the modified Spenc(gt-Cnldwell mcthod The values in table 7 represhyselltativ(I of typical results indieate It -atisfactory dcglpe of conformshyjty between the two methods in thl range of tiSSlHH with llHHC than OJ) percent of rubbtImiddot On the bnsis of the amounts determimd the results in this runge for the plmiddotts(nt lIlcthod ayernge apploxinHltely j percent highcr
~LAIII~ 7-(oIllJl(i~on of lltlllrIic (IIri mOtllinl SJl(II(r-(ulri-wall IIIrtlwrl~ of rlrrlIIillillfl 11)1)(1 COIIrll of UI(III
1 Flowers frllm amiddotmonth-oltl nursery plants
YAIIIATJO- OF SIli(LE DETEnt1NATIONS Fnoll TnEIIllIEAN
Rllbbel (Uall8i8-Thc plcCision of thc pLcsent method when gunyule tissues Hr( nnnlyz((1 for rubber may be j udg(d flom I Ill datil presentcd in table H TIl(se dahl -how that thl pplCPlltag( uriation of single determinatiom from nwan yullles with low standllrd enolS ranges from less than 1 to 4 p(gtrlent
R(8in~ wWlsi-r-s lndi(a((1 011 page ~j he INntlts s((uled hy the present phoolllttric nsins llHt hod are not tliltly (olllpalable with those of the grtLVimetri( ncetol1l-cxtlt1(tioll II1etho(l Thjs made it necesSllry to selc(t another lalibllltion staudud-tlll Ipsinous exullate from gullyule shrub-thut gies relatively COllstlllt photometric readshyings (table 5) The resin (olltents of guayule roots branchcs or leavcs usually ran(~e from about) to 1-1middot pelcellt The ple(ision of the present methotf WhCll gUHyule thslllS lIe analyzed for reins may be judged from the datalHmiddotpscllted ill table 9 1h(se data show that the p(lcelltage variatiun of sillgle lhmiddott(Lminntions iLO11 meun ynlnes with low standard NTOrs rangcs from about 05 to 4 percent
bull
bull
bull
bull
bull
RAPID PHOTOMETHIC DElEruIINAlION OJ RUBBEH AND HESINS 35
IAIILE 8-luriation inclieute rubller (mallSM of [1wIIle tissue bll thc 1111O0Illclc metwII
Vnrlntlon~Ilbher I (rom mean
ierCtnl Percelll ~OU -22 ~ 25 +27 ~ 20 +18 ~UO -22---------1_______ 51110 0G6 bullbullbullbullbullbull _bullbull
10 ro ----=ii41075 -01 1000 +11 1010 +13
rlln HI itil 1l9~ 1_ ___ =-~~~
115511 ~ US -111 III II 1575 -13 115 b tiS -I a 111 h WlU +22IIM-(middot bull 11K -1Ja Illi c 1000 +03 1J5H1 W +l)7 ll1imiddot tl 1575 -13
Mcnn 15951 131
1102-11 21fJ() +21l102-h _ ~~)SO -17 1102-c bullbull 21CO +21n02middotd ~OIiO -26
2 r~plusmn Il~ 21151 261 I -~-------bull---__ _~~_~______l-___--_
1 lhe$ 1111($ I1n (or SlIlIIllltS Stpnnltplr PHrilClld IIrtlrdlng 10 1hr prollIlIlr( OIiIIiIl(o(I on Imgt$ 4 to IC ~tcond nUlI1 hlr r(J)[ltnts stl1ndnnl llrrot of tilt 1I1(1111
1_1l1~ n-J(lri(iot in relli(Upound rpoundsins (lllalIsfs of VIOJII( lixsue b1 the lhomillric lII(lloli
-- ---~--- - __-------- shybull I I I I Varlgttton
_________~___ ~~lu_n_Jl_Q_~~~_____ ______I__~_o~S_J frOID lDean
Percent Percentgt458-1 ~65 +41IWtl-li 130 -a2Hli8c aliO +26S41i8-d bull 130 -32
1(-011 34I10Olifgt __ bullbull __ ~--====
li-9~2n 881) -06 li-9~2-b Si5 o ~HH2middot(middot S i5 -6$-H2middotd 000 +1
8851 054
O i5 +6 9 i5 +6 950 -20 U75 +6
H-liG3o-n bull -1 n-li6~b bull __ _ -IH-IWH +4H-l61511 bull -1
1tmiddottlU
62~-lI __ 62~-b ij24-( bull OH-Ji
(-Ull
I rll(St oluls nre tor separately ~xlrflCled SllllllllCS IlctOrdlug lO procedure outllned ou pages 4 to 10 i Secoud number r~prtgeulS stulldMd error of lIe menn
36 TECHNICAL BULLETIN 920 t ~ DEPT OF A(]RICCLTCRE
ReUUER A~ALYSrS I~ CRCOE-RcuUER PROOCCTS
Sew rapid photometric m(lthod~fol the ddellllinttion of rubber and reii Hi ill uaYllp ti--ut htp lllell pIPHnl pd oil pag( ~l to In A brief H1111111tlY of It similar rnpid llHthod fm 1I1hb~rllnltlysis of u1lulcanizNl tlIldp lubbll pl(Hlmtlt whielt i~ bn-(tldo on the prill o
ciples dehtilcd tlllLe follows Duplltate nt-gm sllmph of the finely cliyiliNl IlInttlitiup wlirllll out [~ei-()l (all hl lIf((tinmiddotjv INd to lt1iyidl till alllpl) TIll kltolll-olubll portion of till )111(11( tlrc di-olved a- indh-Htpd fot thmiddot lllnkill~ of -tlllHlunlluhhll olutiou Oil Pt 1II hut tIl IUlIp Hn lIn l-fplImiddotd 10 lHI-ml rolllllltti( fln-k antil1ltld(lup to Olllll1l The bnlulUp or till JllO(ldllll i- thatutlilllll on paWs -1- 1 IHI Ii 111( 1(111 1- nIP IXPIP--pd nil til IHi or Iw oligiJla w(lullt of I Ill (I11l1p-I1l11Ilt1 1)(0(11(1
Hupitl PlllimiPJojgtiWllllllllh llIltllOd~ fOJ Ihl llPtlmiddotminntion of ImiddotUlJbll tlnd 1(-illo- ill -111111 Illllph of gutlYllll tiUl IIll dl-eli)ed 111() IlltlY d~o Ill nltlI1lld fOl III Iwl Illhlwl- and l~iJlmiddotb(lLiJlg plant TIllt l[Olllhup hns nlo b(l1l ntuptpl fot IIH lltlIll1illtltioll of lllhbpl ill 11lHhrublwl Pl(Jdlld~ HIIl 1111 hI ndaptld JoJ IIll ann lysis of ynt1J(gt( ic lllbbl[- The llllthmb HIP 1gtn(11 fill tIll fol1owill plimiph- III Grinding
tIll PIOPlly driPl t i~lIl 01 Ul tillg tIll pnHhHt to tll l((lllilllllh~lel of filWlH-- til plllllit qIHlIllilnth( lXIIHtioll 01 IIlbhlI 01 1(--IJl- () llsing oXWllutld olnuh (kttoJls IIt(talp and() fllltil for LIbbel and IH(ltIlIlyptIJllIllIoolYlnJld-o flJllh 101 niJlsl with t(lathelr high IlPililig points 111 to n C) l]olle or in mixt tIll thllt Pll mit tlll rnphllxututioll of luhll(l OJ [middot(ill ill ~() to (l mi1lutp It r(latiwly high 1lllIllllltlltP Ill to 1~11 ) l) lllllipitntillu till luhblI OL Imiddot(ill frolll aliquot () f till oltn ion I IlIlllI-i () f Hlltabhmiddot pl(~(i]litallt (willifhmiddotd lthmwl fOl IIlhlHI Hild llitlifild lllr fOJ JP-illl t~) IIlHkillphotollllliilPIIIIiIlof PlllPlltal of liht tLaIlS mittUl(P lIftlI IlIlbll (II Il in PIlipitalioll 11 II WI( Iplllh thnt (limiJlall till PIIOl dill 10 xtralllOlh (0101 (till dptl1minntinll Iph jill 011 tIll dtwlopllIlJIl of H HIli rOI1ll tlllbidity 111 hpl than I (olot rI
jJlIlpOP-ofallnlyi-I ( p(lllil1thb IIllijOI1ll turbidity or 1llt[lIinmiddotd d(ltl of jgtIp(ii(JlI l)~ lIltlkillU tIl plllltollllmiddottri( ntdillU al tandinu tiJlH~ (dlllilll wlli(h IhlllH(lill-- IP 1llutinmiddotly tnhll) t1ll1t an hlsl~1 oil the (oJlItlIlllItion of IIlhlHI Ill I(ill (lIPIipitat((L
TIll -I(p ill till jll()(Plhul HIP 1-- follOylt (1) 1l~UIIL uJ1lplls of thwl UJfJlllHl (II tliddl(l HUt dlipd 11Illtplial an lXIllltel with11 Ill of till nlnll ill t (oU tlllltIPlll[gtPImiddotatlup oil Iath at 11 Cbull fol 11 minutl I) iIP1lIin(middot(lohd til( (XUtllhllll Jltldl lip to It middotml ynlmlll til( (nlifild by (Illlifllgiuu HlId thlPl IlI nliql1ot of tIl (IalioPlllxUlltl nll Uillltlmiddotll(t to l-llll OIlIIlIllril fiuk- (1) For a trial Ilnditlg 0111 III tlll j liJmiddot~t IllHII IIjI to Ohlllll with lilt Pll shy(ilitnnl a 1(11 it 111 (Dod fill llli lIut ( ptotoJIIltlil IPtlllillg-- of pllllntnl or liuht tlUtllIlillal(I oil n (lpel OphotnJlllllI at rase hng-tlt (If 11 llJ Ill Ol It lollllil1lPtImiddott lloyidld with tIll P10]11 I 1110110shy
Ihlolllltt hmiddot Ii1llI Olllhi lIatioll for -1IpItillg UJlproXilll1l tply Wtl P ]Plwth )0 mp are HHlltk TIll Illldillg lliJtaillld fol tIlt 4-milutl tliall(~ll-
bull
bull
bull
RAPID PHOTO~IETRIC DETERIINATIOX OF R(BBER AXD RESINS 37
ing are referred to a table of equhmiddottllut~ previously p1(pa1elt1 on the
bull basis of 4-minute reac1inJ~ for tilE nmge of lot1telltlatiol1- of rubber or resins to bE elHOlll1t(led tmd gidn thtmiddot -tnnlillfr tillIP fill rUbbEt or resins aiter prE(ipitlltiol1 lwfolE photoIllNliI j(tltlill1 un IUade The r(middotnmining dllplllatt aliquot lll then HHllil up te ol1l1Jle and lpoundadillg ale marle ut the -tandillfr tiUlE iudklltll ill rhl tall1lmiddot for the final r(adillg~ -1) 111( milli1lnm or p(tCPlltllt- of lllhbpL (II 1(-in pr(s(nt are rpadholU a prlpan(l table of lquiltlput for tlll photoshymetric readings h1~l(l ill pnell e1-E on pxpPlilmlItal lhln 1111(1 u-ing as stimtlltlds pure luhbll in 1l1bbtl milllYb aIHI guaYllh ll-ill- lxIHlatt~ in resins detNIl1111lttion I
LlTERATlRE CLTED
(1) lUnSbull 1fl36 THE mURMIXTIOS IIF IOTA RE I III OOl THER llT~II
F1 bullrol IlY U(T1l0fll UfSlfi ~rrnrl r flm lt1 KEYS TI Bill Chern 114 44J-l59 illns
t1 ~ICPHHlObullbull T 1J3bull~ lUTHOO roa THE PtRInCAnu Or a(lIUl IRrIlHU It of TIn
PLRIHEU Htllllflt [ i Bill lallllall 111 Rmiddot 711middotj iIlus
I ) RHBERG P B Ul5 A METHIlO Or ~u(ronrll-nl Hi tIII rUIl[1 f71 ii illlI
bull 14 Hoss W flbull and HARDESTY J O
llH IR1ltDII Of HfITilIZfmiddotR DllIJS ltt 1 Yl fll Off gI bern JIIIlI i ~middotmiddotlf IIl
101 SPEltCE D nnd CuoWELr ~I L 1933 DETER~n-ATIOo OF RtBBER Ii nrllllpoundRBfR Iusr 1uI II1 amI
Em~ifl cttIliIa~~ r Ell i 71middot7i l11 (HI WALTER E D
1U44 ISO~nlS OF PRTlltSrr 1trHpoundV bull l UI n W lHHt (Tnmiddot 1ETS FROM GiYI l~iIl lItr Clttrn SII J UI titJ middotn9--C1 ilIu
17 J YOEbullbullr H lO~( roLORIlETRT 771 IPmiddot nl -W Yurk f H Plrwptric hmica
naly-II rimttry lUll XphHHlnmiddot~ y 1 1
11
HI) ~ fPHELolzTRf 57 111bull Lin xw Yk t H lt PhmeHt CblUlmiddot ila AnaiY~l~-(H lithrry and XIhmiddotILpfIY Y wirh enomiddot rrJlllrjr hy H KtlJnJU11 I
t~1I --- and ~ARVER L 1f41 nlua-w ~in L liLhr IS IP ll~ XIW Yrk
bull For-sale by th~ ~a~fr1nt~nf1ent Dt~c~~ogtnts-~ s t1i rArnn~ut Pn~~~ tJffieshy
Washington 5 D C bull Pl lU ~nts
7 RAPID PHOTOME1RIC DElERlHNATION OF RtBBER AND RESINS
bull
bull F1(rJm 1 ~ UIIIltan 11l~IIlInIPIII lo UIIlallt-lllllplalul( ~(II(Inl-[lllrpose hath 11fil1l liS au oil hath Xlltl ~IHinl 1(IIIOIullll win 1Jt[PI 101 holding ~[j-lJll Yo1U1l1plllt flask dUIlng- (xu iOIl ur luJhl t IHI IIill IlIi is uot stlludard ltfJuillll1ll1t nIHl 111lIt hi 1Ill((1 b1 (hI Hllal~-t
Ilm1ll E JIItnslIlPil iIIit (111([ (Iltaslll(11 [1111 In(J nlHI K()(lak electric tinwl Ilw Hutpl H~ 1l~Id ill I1PIIIllIillillg )1IIIdillg (illll n((uInl(l~ 111 111lt minute unll luhllpl HIII1 Isllll al( l11(ipIIIIlP(] 111111 till tOIlIlPI 101 tinling hlHtillg nml (11 tli fUli Ilg 11l1iulls
AWill~ 01 It Ball amp I(wpllluill fol Ull initial lWUSI glinllillg of gtllyul(l UsU( Hoss-llal(]pslr IIWllifillIlioll of Ihl lInlllllHI 11Iil I I plIlIilll] with Xo 1
(~middot1Il11l) nl1d XII (iIIlIII1 (lPIItS LYIPX i lUl(l lOOmiddotml oInllHUilt 1IlI~ llloidltl witlt grolllHlmiddotglns RlOPflllS spr-ial mIIIi 11lx ItitUllIti IIllIkll wllh UIlI illlIlp 1111111 1111(1 gillS
10(1 12 CIIl iclllg h~ 1Ii jlll ill Ilillllllitl wHit gtOllIHI UnllIIPti IlId 1 em In dillllllll fOll1~p illlllllldllg lIbhll slutlon [fig A IUHllJ) 11)( jllpiul heakcr I lIJIIlI1fIIIIIlII11 t101Il Ihl W-1l1I lldUiIl low-fllllli 1IllkI wilh s[lout laquo(olning (llas WIllk Xo 11111(1) Till ll (toul I flatlll1lt1 hr (Ill lgl1lu glllliliIIOl[ing Plo(Il1m Ill IillltllIllI 11111 of Ihl gIllgt ruti aIHI IIIP sUIfa(( lit til( lIat insitle hottnlll of IIII )11111 nl( gIlltlIHI toglll)I wilh Itll(I~ ill 01((1 II) s((Ule the most II tisflnlory SulfH1 rill lil Illl I iOll
P~I(X WIIlIIt glI III 111( ll111L ill thilkms 10 II~( a It tIHS(~ III ([hiding luhl)(I Sfllll[llp
A Iolk Imil fill lISI ill diiltlill~ luhI 1111[111 H(Hy(Inl~ 1~T(lX 10middot1111 gllhmlllI (Pili Iifugp t 111H Ill]lillld wll It (011(1 1101111
lind (ork tupp (0 tit I Ill 2 ()
bull Filt1 tilk (fig 2 IJI 101 1)( with Ihl glltllunlld tublS ill thi o[WIati()n of
llOUling lIIIlillpli lx(nll illf jIIlI )lhIIIl1IY(I lIask IYIIHIlt ([illlluin l(slmiddot Ill At hp II11IPI a )Iuss lOI wit h I tIaltllll(l (lIll lIlS lI1ullIfnlul((l ill the Illhllln(()I~- fol this l1SI bill ii In (lilli(ll1t 10 -1(111( II PIIpound((( tit Howlwei tlte anilnblp filtpl ti(klIt1 tlll 1)111)111-1 lind was Intll lIhs(i~llll(l The fritte(l glass disk SII(S 110 rUlli1 lUll Ill llIlI in tliH O)IlIUlhJll hut hollis hlllk the liqllid II nil lPidlH in till ((111( PHill
Cuullipl(1))ipp(ll for tlllII~flJItng klotlls nnd uthI IlIgnnk Illnnis SlIInl pighin) III I (h li (Ill high alHI (III ill ([111111(1
8 TECHNICAL BULLErIN 020 e S DEPT OF AGIUCUUlUlUJ
bull
IHHH middotmiddotmiddot~Ollll of the ~Jl((iHI ~lnsswlI( reshyquilpd 101 [lh)lI and I(sills tllal~sis (lllss rod wilh lInttPIH(] (ml Loll alld tlitulatioll lJlll((I II]) 101 liSP ill bull IIlnlln~ sto1 solutions of IlliJlPI (olII1i lwanshydlltr -AIIlI lYIX ((1I11ishyrllg tulJl wit Ii 011( poillt (0) nIHI flIIpI stie ( J) I fOlllSP ill P[)lIill~ utl (llIdiIli (X( lels witlt shyout di~tlllhill~ the inshysulilhll Ipsidlp
bull
Glns pound1111])(1 ) jlllll in ((iamptl for 1( ill tltlm~rprljlJg- pighpll fllJlplpS HIIl1
bull (lnrin(d IXIIat to -llil ohllnlllI f1aI~
i(p-mollllt gingt hntl will llntit OJ 11I(lal J(IP (n] fOI toling- gIollIH plallt samp(
Halmiddotk for hllldhlg ill-llll middotPIlIlilnp nlHs IIIH ~i-1I11 YOlIll1pllit flll (Jig- 31 Alltolllnti 10(1-1111 ~middotI(lX IlIllPUp of IhI fq)p llsltd fOl Iitis with intpl(middothallg(middot
nh1t H(JlIlHI joint 101 rl1phl lPfIPIIIlg (lj 1lIhhpl fllld 1(ill lll((jpiltlllls
bull
FllilHE Had Iqllind fool IIJI(lill I 11 (111111111laquo llllmiddot alHl (I) limJ VfIlIlllllJi( tlak~
bull TIll itl1jHlIlWI of n Illb tlpl of d(Hdill(~~ III [gtJ(Jtnllllllil lllll~
i dblmiddotwmiddotpt hy Y (J( I _ j J i) t Illt riflllmiddot t tth~ n n Ii 11 111 h111 I t1loOIlldy witl nap lllltlIHI 1111 1l1id bpll tlll- HII lill(ll with (jtt11lill olutioll Hlld ltll If fla k It It [lllijljtnlld 111bhll nl
11ill lIll til ~tlllld all 111th Ill lillI Illmiddotforl 111l In 1(11 it j~ luhmiddotjlIll] 10 1111 0111 ilH (111(11 11[ Jpli~ Ii tllp wall TIll
10 TECHNICAL BULLETIN 920 U S DEPT OF AGRICULlURE
25- and 100-m1 volumetric flasks arc rinsed two or thrce times with tap water and then with cleaning solution al1tl watel as is customtny In all cases the rinsed glassware is dried in an inv(ltell position at 100111 temperattlre 01 upright in a drying oven The flasks used IoJ extracshytion of rubber Iron1 kok-sagh)z (Talllrl(((IM1 kO-8aghyz Rodin) are finally rinsed wHh the solvent to be used and are nllmnd to lt1Inin and dry under a ventilated hood Cuwttes 01 absOlption test tubes nre handled and cleaned aH directed by the manufacturC)s of the llhotoshymetric instruments used
RUBBER (CAOUTCHOUC) CALIBRATION CURVES
GENERAL CONSIDEHATIONS
The lubbeL hyclroc~rbon stau(ild is pllpa 1((1 by extracting the rubber from guayule bssue ac(ordll1g to tilt SPCI1((-Caldw(llmethocl (5) 01 by the Holll1lH-HaasiH modification of this method (p 2) The air-dry extraeted ltlbber is dried furtlllr in It vacuum OYCl1 with 30 inches of yaCH1Il11 at 63 0 C for 4 hOlIlH Till rubhlI sbindanl is preshyserved h1 It clos(cl contaim1 sto1(d in It r(fligellltol BCfole th( samples nrc weighe(l out the unopened cOIlbdn(l with the rubber i~ brought again to room tllllpelutnre
Two stock solutions each in triplicate from separately extractml standard rubber satnples nre prepared-the first sct of (-111(( containshying 01 percent 01 1 mg of luhbC1 ])(1 lniHilit(l and the other 02 pershycent 012 mg of rubber pel miJlilit(l TIl( (I(~il(d w(ight of rubb(L contiiinec1 in It known VOlIl11e of th(~ solycntis withdrawn Irom Il
burette or pipetted and made up to 25 m1 the standard volume used throughout the procedu]e
The rubbcr samples (01 and 02 gn1) for the stock solutions are weiOhecl out to an aCClllal) of o~ mg on nn analyti(~al balance The rubber is best mnnipulated by mNlI1S of t1l( stJai~ht hlunt-edged top of It cork knife With a little prnctie( OIl( (an leltlily sepnrate t)w desired portions by pLeSSIl1C from aboye Further subdivision Is mndt on a stout PVllX at(h glnssnt lla~t 2 mill in thlkne~s By pressun f10111 above and sheuling aetlOl1 Ye1~ small pnrbcllH can be separntetl so that the requit((1 11l110unts (un 1)( w(igh((l Ollt accurately The rubber sample is then divided into sl11a11 piC(es on the special watch glass by meanH 01 II coll Imife
One mil1ilit(gtl of lt1i isobutyl ketone 13 js placed in It special 30-m1 trituration beaker (fig ~B) and the fine1y diyilt1ec1lubber sample (01 or 02 gll1) is udd(d and heated on a hot plate under n ventilated hood to Il tempelature jllst under th( boilin~ point of the olvent A special glass rod il used t () t rit II ate the sumple (fig 2 11)
When the rubl)(r hll d issohed so as to makl a hOll1og(J1lOUS geUike 111I1SS hot methyl isohutyl ketone or an oI the other luhb(L solvents recommended (t aIJI( 1) is add(d and niicd with the rubber soltItion
31 Diisoblltyl ketoul WIlS not aailab1p (Juring ValtimC l1Cthyl isolJutylletonC 1II1ly be substitnClt1 11111 it is not a~ Cf1kiCni In Illis olllntion If the IllttC1 is used It is b(SI to pl Ilw fimlr diillPll Iubhpl palll(s slan( oPIuight in Ih( solvCnt lind 10 (OPl til (onlalll1 to IllinilllizC elIpornt(111 of sohPIII bpfolp wa( Is nppliecl to completp nlutioll
bull
bull
bull
bull
bull
bull
RAPID PHOTOMElRIC DElERMINAlIOX OF RUBBER AND RESINS 11
The mixture is tllll1sterled to It 100-ml yolumetlic flask with sevtlul washings of hot solvent cooled to n s(uHluld telllpelatUle and madtmiddot up to volume with the saIne solwlli SlwtiaJ IHl(uutioll mllst be takell in transferring t)( lubbCl solutioll to till YolulIHtrie flask so thnt llO rubber is lost It is cOllytllielit to illSllt It j-ill(h funnel in the ne(k of th(~ voiumptic flask to pOll tll( lubb(ll solut ion ill OIl( OLWlHtion into the tube of tht IUlll1ll with Ihl aid of tIl( glllss Iod nlld 10 follow illlshyl1eilintely with S(gtllnl ~Ynshings of hot S() I(111 whkh lIl lilst pouled 1nto tIll btll PI 1I(ld dIIleUy OW) till 1unn1 aId IhpII t1I1uugh Ill( funnel
H time hi not all objllt it is uls() flasible 10 p1alt Ihp linely diided particles of Iubblt ill tl( flask toJ1tuining Ihl sohPIlI 11(1 allo it 10 stand until til( 1lIbbpI is dissolYld TIl( llIblJll ioluliol)s alp slolpd in Ihe tightly s(ojlP(1(d OIUllwt lit f1nks in a ((lol dark placl Thel they willltIIlUlIl (OlUilallt ill Idut 101 an indlfinit( JlPIiod
Two ellliblHliol1 (IlP~ flIP IIltl(l(-OIl( 101 o~ gill of tisHlIP (ollin illshyhw 0] to 10 PII((Il of rubb(I ((1lt)middot1 to U mg of IlIbb(Iill tt ~)-1Il1 yo1ullll) and th(middot otlHl for ()~ gil) of tisslIp (ollaining 10 10 ~l() peLshycent of lublJPl (O to 10 Illg of lulllJpI ill a ~)-))Jl YOIlII1IP)
(Hns HlJ 111 TO 1 II~IWEX( (II BIIII1EH
III oldl) to ll(llllP (ITOI (0 II Iltinil1lIl1l a lIitahl( lllillobllllltp is lIs((lo Jl((lpn (P IhI ~lt of stal1da Id solut iOlls 0 f a Ii ng (OJllllllllll ious ill til(gt (III)(r( Ol 10 1 gt(I((lIt of LubbI In (11( PI(sPIII WOlk th( 1111shypIoypd HlhlHIg mic)obm(ltp Il bullJ) whkh lIi(IlJalpl dlli(I~ 10 0001 1111 was Toulld sntisiadOlY F(OIll n lll-pltIllllt -talHlulIlllbwl solushytion in HSlIitnbh solnnl lt[lIiIlIUJl1iiat( aliqll()l~or n) Ol o~ n and ()t 1111 al(lllla~UIpd (Jilt ut n stalldUld ~Olllli(lll tlIlIJl(1atulp (~) C ill wlitllmiddots labolulol) I IlIIHIl-of II lllillOillIl(tlt illio ~l-lld yohulI(lie f1nks ploid(d it h gla -(OPIllIS gllollgh of 11ll lubhpl sol Pili i~ thllI addltl to (tl(lt flask to IlIak(1 l 1111 Ill1I IUI(middotc (0 t hl all)ollllt of lllbOPI solutioll ]ll(yiously nd(lpdbullflll DI ntl 01 JlImiddototlmiddottli lolloid solu tillil Iras h(PIl Hddld lIP (bhpl is JlI((i pi III tpd IIlld SP(middot(t )opl)()tolllshyd(gt( 01 (jIOlilllltp) IPallil) an IllHdp 1I((OIdillg to 11ll JlI()(pduJ( Oil shylitwd Oil pagp 1middot1 Th( 1(ldillg~ 101 palmiddotll (OI1((III)Hlioll alp 1I(Iaglt1 anel plotttd Hgaillsl t( ntilligllIlll of 11))1 hI n ~)-1ll1 (jIIlIlH 0) [gt(lClntagl of nlbblI (nltuln(pt 011 tw bnis of tl2-glll lilsul Slllllp1(gts and aliqilOt olulllt IH(IOI 101 (itl ]1I(J((dlll( out lilll(1 Oil pagl 1middot1 This PI()((lhll( i ((l(alld t win ill (a(1 (11( II slandald llIbbllsolushytion was PI(gtllllpd IIOIlI slpa latll XllH(1 ld 1 a utln)(l lllbblI 1 III pips TlwcOlllpl(tpdtlla alp pol(l (1) (loldilla pap(laslrowl1 ill figulp I
Tbl )llO(p(II I ill lllilking a (Uln rOl I to ~ jiI((lIt of JlIlJh(1 i~ simi1t1I to (hat rOl 1Ill l1IlP ImI1 to 1 JllI(PIII (x((pl ill a f(middot dptnils The quinlu]lli(Htl aliqllols a 1( sput(d Ht (lI 12 a j 0 (78 n alld 10 mg ])(gt1 ~i-1Il1 Yolunl III sNuIing thp 01 Illg pll 2)-Jll1 YUlll))lt til( (gtIO(ltlIII( outlillPcl ill IIIl PIp(tding pnltlgllIph is followpd In the rllngl 1 toj Illg )IN ~)-1I11 OtIIl1I Ilw (lsi 1(lt1 (oJ)(tlllltlliollS of lubbpI alP s(gt(ul(gt(l h IlIPHsuljng alhplOi- with Xnlional BIII(atl of Stnndlld~ tltllsf(I pip(Ws flOIl) tltl OI-PlIl(1l1 lII))ll sol III ion
12 TECHNICAL BULLETIN 920 U S DEP1 OIr AGRICULTUHE
RUBBER IN 25-ML VOLUME(MGl
100 1~__middotOT5___ITO___15__2~O=--_bull 2r5_---= bull 3rO__~-_40 bull99
98 shy(I) CI Z
~ 97 ItJ II
~ 96a f-IIJ
e95 o l
94
93
92 ~__~__~__~____L-__~__-L__~L-__~__-L__~
o 1 2 3 4 5 6 7 8 9 10 RUBBER (PERCENT) bull
FIGURE 4-Cnllbrntioll curve for rubber in 02 gill of gt1n~ule tissue containing 01 to 10 p(rcpnt 0 lllbhlI (nlnllillg~ (Ill 1111 J~pl~ll llhooplf(middotttmiddotlc colorimeter with 720middotmu filter und amiddotml uperture the 01 divisions required in actual pracmiddot tice for photometric IclHlings arc olllittltd)
Similarly hl the range 5 to JO mg pel 25-ml Yolume the desired conshycentrations of rnbber urc measured from the O2-pllmiddotcellt solution The complete data lire plotted on semilogtllmiddotithmic pttpel as shown in figure 5 A
STANDARDlZATJON AGAINSL G1IA111 ETlIIU 11 ETHO()
1he alternate ploee(lule of stt121l1ald izing th~ IneHell~ method ngninst the Spellcc-Cald well method (II) altholl~h flaSI hIe 18 not adVIsable because of the extra work J(quiled ancl the introduction of the expershyimental error of the benzene extraction method
HESINS CALlBllATION CUIlVES
The procedure for constructing cal])lation eUlves for resins ttIlulysis is similar to thtni outlinlltl for lubb(l lxcept that resins exndate of gunyule is lIsed as the resins stundard The resinolls exudate disshysolves very readily in the resins solvents listed in table 1 It may be prepared in two ways for use as a stnndard-the clean exudate as bull gathcrcd from the plants is dried for 6110mB nt 65deg C nt a 30-inch ltcuum or the oXllllate is dissolved ill acetone and filtered In drying
bull
bull
bull
RAPID PHOfOMElRIC DJllImlMINAlION OF RUB BEn AND HESINS 13
RUBBER IN 25-MLVOLUME(MG) 2 3 4 5 6 7 8 9 10
r~
eo en ()
90
f--70z Q ~ 60ltl LIJ a ~ a LIJ 40 E 0
0 50
~ 0 ~ I 30 0 ~
A 20 I I
o 25 50 75 100 125 150 175 200 225 250 RU88ER(PERCENT)
RESINS IN 25-MLVOLLIME (MG) 2 3 4 5 6 7 8 9 10
1--90
80
en () 70
I z Q 60ltl LIJ a
50 0
a ~ LIJ 40 E 0 0 ~ I 30 0
B ~I20 o 25 50 75 100 125 150 175 200 225 250
RESINS (PERCENT)
lJIGunE u-Cnlibrutioll cUve for (il) rubhcr in 02 gill of gllnn11c tisme conshytainingl to 2G perc(lt of 11IUU(Il I1na (1]) rpSillS in 02 gill of glI1~l1ll~ tissue (ontnining l to 20 nelecnt oC l(sin8 (U(ndings Oil 1111 E(lI~1I llhotollectlit colorlmeter with 720-mtL filtcr and O-ntJ aperture the lO divisions llquired In uctnul prllctlce for pitotoulPtlie PllllillgS tlre omitted)
in vncuo arelntivply HllHlll qUllntity of (xutlnte is plllcel] in a lalge dish since the mass rOHmS nt the beginning of the drying process Pracshytically ull of the ne(tone is evnpollltpd olf oyer a steam Ol WItter bath and the residue is dli((l pnlYllized in It mortnr and preserved by
14 lECHNLCAL BULLErrN H20 U S DEPl OF AGRICULTURE
drying as indicated for fresh exudate In all ClSeS the products are stored in airtight containers in a dark coul place
The usualllnge of resins from gunyule tissue is about 2 to S percent on a dry-weight basis For work with this plaut therefore on1~ one curve is needed A typiCallesins ealibrntion CUlTe is shown in figure 5B
PnocEDuuE J~OH RUBBER ANALYSIS
Duplicate lXiLllCtiOllS arc made for each tissue analyzed and duplishycate photometric readings are made for each cxtmctioll the final value therefore reportcdreprescnt- nn avcragc based on the four phoshytometric readings
Thoroughly mixed O2-gm samples of the finely ground tissue are weighcd for analysis on the basis of l11oistUlc-frec tissllc The samples arc weighed to an accuracy of 02 mg Oil an analytical balance The method of deriying factors for making eOllections for moisture in samples has been thtailed on page
The weighed samples arc trallsien(c1 to the 2-m1 volumetlic flasks with the aid of l-inch glass funnels and 20 m1 of methyl isobutyl ketone is added to each flask The contents in the Hasks are heated m a constant-temperature oil bath at 115 0 C for 30 minutes uncleI a yentilated hood rhe flasks are removed and any adhering oil on the outside is wiped off with Kleenex 01 H similal cellulose tissue the C011shytents of the flasks am cooled to a standard tempellltule (25 0 in the writers laboratory) in a constant-tempelutllre ater bath provided with a motor stirrer if available and made up to volume with the solvent After the contents are mixed the flasks are allowed to stand for a few minutes until most of the insoluble residue settlcs to the botshytom The extracts are then carefully poured into JO-m1 heavy-duty centrifuge ulJls so as to include as little as possible of the settled insolushyble residue The centrifuge tubes are stoppered with cork stoppers and the liquid is clalifiecl by centrifuging for 10 minutes at 2000 revoshylutions pCI minute The clarified lIquid is poured into 25-m1 volushyl1Ietric flasks plOicled with ground stoppers It i impoJtant to pour off the clalificd (dlart in lWIt a lUlllie that the ill8ol11ble cNi(hwis not Sti1((Z1tp A 1-in(h funllel is plncCd in the neck of the volumetric flask A filter stick (fig 2 D) is inserted in the centrifuge tube through he liquid so that tlH enlnlged palt of the gtiek seals off the insoluble residue and a small portion of the exmet in the cone point 1Vith the index finger the stem of the filtel stick is thell held against the side of the tube towllnl the analyst who holds the tube with the thulllb rmtl t11illt1 fingCl The txtlHct is thell poured off easily into the yohunetlic flask without distnrbing the insoluble residne The COllshytents of the Hasks are then ))ollght to the standard tel11pelatme in the constant-tempentl111e wnter hath
The reagent blank us(d wit h the spectropllOtoll1lter 01 (olorimeter ig prepared as follogtvs ) 1111 of methyl isobutyl ketone 01 other solvent used is pipetted into It 25-m1 yolumetric fiask and 01 ml of protective colloid solution for rubber is added the mixtule is made IIp to olume with acidified Oil-pelcent ethnnol and mixed again the rcquired vo]shylime of the mixture is poured into a cuy(tte or an absorption test tube
From each plir of tissue extractions to 5-1lll aliquots 01 the clarishyfied extlact at the stnndanl tempCraLule ale pipcUed into 2ii-m1 volushy
bull
bull
bull
bull
bull
bull
RAPID P1IOTOMElRIC DETERMINATION Ol~ RUBBEH AND RESINS 15
metric flasks and 01 m1 of protective colloid solution for rubber is added to each One additional5-mL aliquot from each pair of extracshytions is similarly prepared to serve as a key to the standing times for the final readings as indicated in table 2 These additional aliquots are first made up to volume with the precipitant acidified Do-percent ethanol mixed by carefully inverting the flask three or four times] and allowed to stand for 4-minute periods before the reading is made on the colorimeter Vith these preliminary rendings a~ a basis the standing times for final readings are taken from table 2 For example if the colorimeter reading in rubber analysis at 4 minutes is 655 then the standing time is 15 minutes
The two rell1Lining duplicate aliquots for eath extraction are then made up to volume with acidified D5-percent ethanol mixed by careshyfuIly inverting the flask three or four times nnd allowed to stand for the required number of minutes as established by the preliminary 4-minute trial readings (table 2) before the final colorimeter readings are made on the contents of the flasks
TADLE 2-St(llllliIlU time for variolls (OllccntratioIlS Of rubbcr or rcsins aftcl iJleaipitation bcforc colorimetric readings mc macle
[5middotml aliquots of rubber in methyl isobutyl ketone or of rcsill~ in ncetonylncetonemiddotcellosol e 3middoti both made up to a 25middotml volume with pr~cipitantj readings on lvolyn photoGlectric colorimeter with i20middotml (690to iiOmiddotD11) filter and Umiddotml aperture]
RUDDER I
Range of colorimeter Approxima(e S~nuling i Rnnge of colorimeter Approximn(e Standingtrial readings after 4middot range in conmiddot tJIIIG for trini r(adings nfter 4 range in con tifillnlOalcor minute stunding time tcnt In tiSSU(l Unnl I t I t (rending IIlIDU C stum Illg lOW _ tent III Issue reading
Percent Villlits II Perfe~lt Jfinul 955-999 bullbullbull bullbullbullbull 09-01 00 01-03S bullbull ~ _bullbullbullbull_ Jl-O9 10 743-954 bullbullbull ~ bullbullbullbull __ _ 43-10 30 1420-550 bull ~ ~ 137-94 5 6_3_9-_74_2__bullbull_ bullbull bullbullbullbullbullbullbull_-_---- 6__8-_4_4---___ bull ~ ~ bullbull ____ MQrcthan 13ibullbull_-~_ _ ____ 15_~elow t~ 2
RESINS -----------------------------~--------
957-999bullbullbullbull ~ 139-01 60 11419-amp11bullbullbull _bullbullbullbullbull ~~ 13~5-939 10729-956bullbullbullbullbull_ Ii 25-1 middotJO 30 ~gtl2-40(L bullbullbullbullbullbullbullbullbullbullbullbullbull _ 2025-1320 5 595-728~~~ bullbullbullbull 8 as-G 20 20 IBelow 292 bullbullbullbullbullbullbullbull- More thun542-591 _bull ~ bullbullbull_bullbull_bullbullbull 038-039 15 2025 3
I Precipitated with O5middotplrccnt HSO in 05middotpercent ethanol When the npproxilllull concentrntion of rubber or rcsins in solution is not known trinl colorimeter rend
ings atmiddotJ minutes s(nnding till nrc mndelS n guide to the required finnl standing time indicated in the last column III prncticc UII cxtrn nliquot is prcpnred for precipitation and thIs is discarded after the trial reading is mnde
3 lrccipitnicd with OmiddotpcrccntlhSO ill HO
PnOCEDunE I-On UESIliS ANALYSIS
The procedure fol resins unulysis is the same as that indicitted for lubber analysis eomiddot(I]lt that f he -olyent js acetonylacetone-cellosolve ~)-7 tht precipitant js O5-perctnt H~SOI in H 2 0 and 01 1111 of the protective colloid solution for nsins is added to each 25-m1 flask conshytaining the aljquot of the extract before the precipitant is added
PnOlmmlHlC INSlHu~mNTs UECoIUlENDED AND CALCl]IAlION
OF UESurlS
Photometric readings of percentage of light transmittance (T) ale made on the Coltnum double monochromator spectrophotometer at
16 lECHNICAL BULLElIN 920) U S DEPT OF AGHICULlUHE
750-111 wave length or renclings n1( mnde on a colorimeter pLoic1eri with the monochromatic filter eOIl)Il1l1tioJl for sllecting the npploxishymate wfLYe ]cngth at 750 1Il~ For routine deterlllinations the Evelyn photoelectric colorinwt(r ployided with aTW-lllJ filteL is IC(0l1111HIHtll
The liquid in hich the preeipitnted lubber uld rcins are susshypended is pOll(d very cHrdully down the ill~idl of th( clette o absorption tube to lLYoilllllC fOLll1ntioll of ail bllbblls Aft( LUbbet find resins preeipitation wlwn the EnLynpho(otkcllie (olo1imetll is used the readings are nmde nft(L thl standing tillll- hOWll in table~ It has been foulld (OIlllliellt to 11lPtipilatl tublwr 01 llsiIlS from the aliquo(s at ~-millute illtlLvals This allows stlilieipnt tillle to check the eOlolimet(r and to makc 111( lNHlings Vlwll a ehangp is IlltHk fLom onc rending 10 the l1lxt it is advisablp 10 llle the clIvctte 01 absorption tube nt lpast twkp with slllall p(Iltion- of the llllltiol to be leitd
After the colorimd(L lluding lta e becll Iltndp till IlIl II igllIlllS of lubbel or resins or thc lpL(el1hlges pnslnt in Ihe aliqllot are r(u1 from cal ibmti(Hl (urVlS (fig~ 4 and raquo or from plepn Led tables of eqllivallBts baecl ill each (liSP on (x[lerimPlltnl data The results are expressed as percentages of dry weight (S hours drying nt 100deg 0) of the original tissue The errol lltle to lCflyjng the insoluble residtH in tbe voltlllletLie pxtLHclioll flflsk wlwn the pxtrnetis being mnde up to YOlllmC is V(ly slight sinlte only (U gm of tissue is used FOLroutine allalyscs lhis ery slight eLlor mny be dislpgnltec1
EXPERIMENTAL RESULTS
The experilllCnlal reslllts Oil hi(lthp method- of tU)lPI and l(sins analysis a le based ttl( d icussld blicfly hlrehl
PHEPMINrlON OF SAlULES
No difliclllty was expPtitI1(ed in pltparing slmplls of llllrscly-glOrt guayule plants 1pss thnn ~ YPH1S old 101 rllbbpl alld IPSills analysis In the cnl of Odll filld-gl()n gllayull plants PIIOtS hopel mtty be introdmp(l by the custOlllalY Jlwrhod 01 pICpalillg Ihp sampl(s 101
HlutlYHis as is lwipfly i n( ita ttd ill th is s((tion Smh enOlS do llot nffCct the ])lCcisioll O[ t1H llwt hotls for LllbbtL n nd Il~in~ nnn I sis i nee till) are due solely to tIl( tbsup--ampling (llo(pdule in thi (a~e of oldeL field-grown plall TIll 1lllt1lOcl of salllplill7 fipld-gl()l1 plants JllOLC than ~ Y(HrS old thenfort Ieqlliles iurtlHl jnttigntioll
lgtAHnOILr~G FOR HEllOVAL OF UUVLgtS
Parboiling which (onisls in boiling gllltyule plants in water [OJ
8 to 1~ ~ninll(s ~s col1llllonl) uSNl a~ n llHans of Itlli rCnl()y~l prior to drymg nnd gllnllng It I~ tHI([())P ll(e~Sllr to ltItLeLnunc all possiblt~ eflct oi tlti PLOtPlllll( )ll (Il( final results Exp(liments have sh(nm that (helt i- fl Flight loss ill til tmiddotjght of lOO(S and 4(ll1S In I typi(ul lXpelillltll hlu1llHs of ~- ii) -1-ytII-old gllllll( pllllb were Italnd at randolll Olll ( of talns wa- paLllOil((1 and the le~es (1( haIHI-pi(kpd [lom till o( hpJ Ht Both pis (1( dlipd for 48 hOttlS at (i) C in a llI((lwlli(al (011((( ion Oyell Th( lpsult are SUI11111I11izNI itS follows
bull
bull
bull
bull
bull
bull
RAPID PHOTOMETRIC DETERMI~ATIO~ OF IfCBBER A~D HESI~S 17
Dry ucilht lust ill lariOilillf
Plaut (pcrcrllO 1 1 -I2 ___________________ _
213 _____bull _____ bull __ _______ ___ ____________ 12 2(
pound(111_ ______________ 1 R
4_______________ _______________ __ _____
A __ bull __ -_
The efred of parboiling on till final lllalp i SUllllllatmiddoti7(middotd ill figmc G Rubb(1 lecoYelY w(t about 1 percent higher for parigtoillltl plants and lEsills re(ovelY somewhat o-er 1 i)(lr(lllt 10Wlr The (Ii tference in lublH-l r((o-elY cannot be ae(01111tltlt1 fot by loss in dry weight _ due is to be found in a study of thE grinding lwhadol of a parboiled and an unpnrboilEcl shrub The grinding of the patboiled shlub in the hnml111 mill is much fadlitated and ns a rule for tissue with a rubber contCnt below 10 peteent llO aggregates of rubber deelop in the 1Il11ehinr during the (Jpelatioll Yitll the unpnrboilNl shrub some dillictdty may 1)( (lxppliellrl(l Sill(( sOllle of till sti(ky ltxlldutl Oil the plant may scI( u nlldei for the fmllHltioll of lublH1 ngglPgates Til is apparently explnins the npparlllt los in ruhbpl frol1l the llnpariJoiled hrllb as eompnlelt1 with thl palboilld (fig (i) TI1(loss in r(sins
II
RUBBER
10 f-
Ishyz LIJ 0 0 LIJ 0
9 --RUBBER -shy-------shy
-- RES INS -shy---shy-----_
IJ) 8 I--Z IJ)
LIJ 0
0 7 f- RES I NS -0 -shy0 LIJ III III J 6 f shy0
LEAVES REMOVED BY PAFltBOILING
5 f shy -shy - BY HAND PICKING
4 I I I 35 30 25 20
SCREENS (SIZE OF OPENINGS IN MM)
FIGlRE Ii EtIe(t IIf pnlticlp sizE Oil lEcorPQ- of rubber lind (iiil1s when lEgttiye wEre remond hr Pl1liloiling lind h~ hand pi(king ((Dlltrol) plllllt1lt groUlld in t hammer mill
6114038-46-3
18 TECHNICAL BULLETIN 920 U S DEPT OF AGRICULTURE
recowry from pUboil(d shrub may be due to the loss of the resinous exnc1ate during parboiling This exudate forms ns It SClim on top of tlw )iquol in the tank
On the basis of t1wse results the recommendation is made not to yaly the nwthoC of leaf lemoYal in any 011( lNi(lu(h project Then fltirly compalabh IcmLts should he obUiined
70 ~------------------------------------------~ LEAVES REMOVED
BY PAR80lLING ____ BY HAND PICKING
60
-I-Z 1amp1 0 50 a 1amp1 a
en 1amp1 gt1amp1
40en gt-CD Q 1amp1 Z
I shy 1amp1 30 a l shyx C)
1amp1 ~ J 20 I shy 0 I shy
10
O+--L__L-~__L-~~--~~~~~ o 10 20 40 60 80 100
NATIONAL BUREAU OF STANDARDS SIEVES (MESH)
FlGntE T-lJiMlil)utiun of l1Ultkh si~(s of gnll~II( tiSSU( JrIOllll(l in a Ball amp 1ew(1 mill to pass six dllIerNlt S(I(euroII 1(IlYes Iemoved from plants by palmiddot boiling 11(1 hand picking ((olltloll dpfo1iatld plants dried to 1I lUoistufl l0I1t~nt (If 01 to o) 1)(ICl1It ground tiSSlli IbalH1 1() minutes ill II ~i$hel
bull
bull
bull Kahn shuk(f
RAPID PROTOMETRIC DETER~UXATIOX OF RrBBER AXD RESIX-i 19
GHl~DIgtiG
bull Th~ entire pant 01 plant l)iHt a~(gt fl r(ll it pllllIIirU1ry lSillg fur J hours ntGi~ C prIOr tD t 1( plChmll1atmiddot rLlmhll III a II lItmiddot or n Ball amp Jewell mill ~n llltllysis of paldch lzP- nftl~l (oar-( IIindill shows that tlwy ar( about tIlt llllH fOl parbojlP(t awl IJllllluhoileu hrubs I fir 7)
The coalilly gloUllll ample i-- thPll Ildlll forI toUtmiddot at ni C afnr which it ha lllilobtllL(gt output of ~ llllut lII hmiddot- dptPlIIlilwltl by drying submlllpil- at 1110 fot hOtll- TIll 1 IIIIll i lltllt lmiddot0l111d hi a IluninHl mill TIll mo(lel uP(t in thi IIIk i 1I Hu IIIOilll mill as IllUllifill bv Hoss nnt Hartlet ( 1 -[1lt111- with n1ll1l1 pldushyrations ittI lilnbhell b rill HanlIolll V0ll11nHiol1 ElIillllmiddotrill (0 The size lutllihl11 iUlJnole So I ( 111m t ~ II t HUIII Xl) ~ I L~ 111m nnd So 4 lillllU1 11 ttllilhmiddotj 0 r tllP Imiddotlult~ p(lln-It willI t11(e Sll((IIiZtS with )arl)Oiltll awl uil)Jtllboiltd hrlll b lOwl1 in fif1l1fmiddot-- This hows t tnt 1middottttIl ~(I 1 llllll (Up jlllilnl IHlt that
r------~-------r--- ~ --r IHAMMER-MILL SCREEN
O~ NO1
NO2 ---shy U NO 3 ---II
I
bull lL
z
r ------ l 30 ~ gt III
i I Imiddot
i ~ I
I 1 I I
~ 20 I - 1 iii 1[ r 10 ~ ~ ~ I _ ~ I r A bullbull
o bull L-~__~__~~__- ~~ 20 40 60 80 100 40 60 80 100 200
NATIONAL BUREAU OF STANDARDS SIEVES (MESH 1
Yutln I i-tlillltiuli Hf pur id lZt f ~naY1l1 t middotnt r1 lI1 i ~ a hatlltlllI 1IIi11 to 1111 Lx IHtllllH middotIn Lt-anmiddot tIlllunl loy la1 litkh~ omrl t 1) tHul parbuih~ -t B ~ thmiddotfuliufptl ]~lahr thpt tu tt fit t 1 It+gtr-tt1 Jnui~tHn eunttlIt _~rnlitl tl~UP ltakmiddot~~ 10 UddU it~ 1 rtmiddot4~pt~middotK1~r ttakt-middot
bull So 1 gingt- 11 tt-liuin-Iy ltr~pl [lPlItl1tat of iilll 11animiddotImiddot- Eqltrimiddot tIlllll hnnmiddot llOWIl dutr fll llltldllllUU xtlutioH 11pound lnhbll lIl lP-ill frolll IolUlIl ~tlaYlllt tl-IlP by dlt IJwtmiddotlUlmiddot lItlilwd oil Ill 14 - 01
i-mllt 11111- -lwltld hi INd I li~ Ii I TIll lllhtIlttj of Itiu~ So 1 (lltll j thnt 11middotmiddot01middot lttwmiddot to amplil tltt Iollllli tilt art lpdnn ib
IntIIll ll~ i po--ihJI with tI lLllit Ilfltl[lll1t It honld l Plllplw izmiddotl rImt ilt tht h of -allllhmiddot with l lllblPl
~ontlnt of ill PPltllt til lIilll it i tlllt pll--ihl 10 11-middot t(1i Xli L
20 TECHNICAL BULLETIN 920 U S DEPT OF AGRICULlURE
Even with screcn No 2 difficult due to rnbbel tlcrltreCtlltiollS may be ob tl
encountered In thes~ caHeH it iH lWit to parboil the shlub fOL leaf lemonll and finally to dry to about 1 to ~ P(l((llt of tnoiibl1(l pound01 b(~t results jn ~rindillp in tlH hanmHl mill
It iH aclvlsable to provic1l thc hammer mill with a ground wire Hillel the presence of static electric (harges 011 tll(middot partkhH will ealls( Home of these to atlhelc to the inside of tllP (olltailWr OJ lila eallsc OI1l( of till pULticl( to form ngg1(llatls EIIolin lalllpling fl01l1 fhis SOI1I(I mlly be (onsi(h1llbl(middot
A1I10l1g the Holnllts with high boiling point that lIlay Ill IlHld in rubber anal)Hs I1IP Illllhyl n-alllyl ketolle methyl ioblltvl kptOIH diisobutyl (tOIH blltyl tHptate llethyl amyl 1Ittail (middotthyl(middotlllmiddot gly(ol diethvl (middotther and n-bntyl (middotthel (labl( 1) TIHse al( also I(sin 01shy
middotent but th( 1(~illS n1( held ill olution by the rll1)bpl pl(l(ipitant tthanol wll(1 lllbb(r is 1)J(lipitatNI (S(ll tabl(s alldmiddotl) On tIle basishyof the lxpHilllPlltH tll( btsf nil-round lolPlli -rol lS in 111( PIlHPllt method is lt1iisobutyl kPtonc wld(h was not IIltlllllfaltllllmiddotd ltIlling Vodd Yflr n A suitable Sl1lgtstit ute iH llHthyl jolllltyL htolt whi(h is l(porhd as llolltoxit UJ)
Clllos()IY(~ (ethykn( glYlol monopthyl (tIH1) blltyl earlgtitol (di(thyl(ll( gly(ol llIollobutyl (ti1(r)~ and acttonylacetOll( may be used as resins sohrCllts (table ] )
In the earlipr work with (sills analysis cpllosoly( alolle was selcmiddotet(d as a suitable solycnt Aitholllh (ell()~oh( alone is pxc(lllnt its rplllshytiwly gwatlL iscosity 1(I(b to bubbl( formation nft(I (SillS pr((ipi tatioll Thi- increased thp (xperimentnl (LTOI OIl of tltp othll I(sins solpnts tI((tollyla((tolH has the proppry of glpatly lNlulingshydH(OSity 11(11 altld(( 10 othr liquids This sohpnt tlHIeforl wa addp( to ((Uosoh( in slIflici(lJlt tlllIonnl to OPI(0111e the dinieulty On the basis (li~ex)le1inwllts ~ purts oi~ a(donyla((tOlll to I puts of (elloshysoh-f (bolll by olume) as Splldcmiddot(l Thp 01 hel Hoh(nl listed hutyl clLlbitol at l(llst the t((hnieal-g1lld( ploduct uSNl is appal(ntly not as good as eithe of t1w ot1(r two () a (ombinatioll of tlWSt
The SOlVllIts JOI liSt in tumlyzing artifkial lubbel$ hy tlw pr(senf method appllLently (lcllIHl on th(middot kind of llI))(I lIp-ityl (Jxidt is suitable Ol BUlla fi and hutyllthlI for butyllllbbl Tlwse reagents IlLe technical g1lld( Calboll amp CtllUil1t Ch(lllilai (OIP This Hllbjp(( hilS not bepn (XtpllHl(ly illwtigated by till WIit(I
PIIECIIIIJ-
All tlst fOl Ih( adlqlJalY or till IHllipitullb ll(Ollllllentillllll11Sl bl baset] on the plctisioll of tllP final I(snlts oiJtairwd with the methods The )redpittlllts s(1e((( n HpJ (xtcllsi( (xp(IimPlltatioll all HatiH~ factor (Hee fig Hi 111lt1 tabItmiddot (jH) Ext(IIin tllts llllTild Ollt hanmiddot shown that H Hatil-gtflltlOIy [gtIpeipitallt 101 1lIbblI is (li-p(IT(middotnt HzHO (c p reagent nil POll sp gl U-lmiddotJ) ill li-P(l(Put (tinmol by vohmlP liol (tllayul( Ipl-gtinl 1l)-P~ITImiddotllt H)~o ill Hl) by ollln( ii lL satishyfaeto7-y l)lp(ipitunt A solution of 1 palt of H~~o to 1 part of H~() (1-1) iI2So1 nnd abo yarious int(lIlIPdiat( proportions of tlllse suhshystanCPs giyp fait 1(511It8 but with till inlIptl(l ill [h(gt ratio of H~S01
~
bull
bull
bull
bull
bull
RAPID PHOTQlIEfRIC DETEMIlXATIOX OF HtBJER AXD RESIXS 21
to H 20 the )olutioll becollles somewhat vbcou5 and precautioll Il1Ult be taken to ttvoid bubble formation When it i5 poured into tilt Cllvettes
It should be lloted that both of these precipitants have an ftellleshymmiddottion It was found that when XHjOH was used in the rubber preshycipitant in pInt of H~~O~ the readings were -table l)Ut were not reshyproJutihk The lIl of XuOH in pInel of H 2SO j ran nHittble result as a llth H(HY(Pl WIWll til( li-P(l put lthatgtl in lublltl llnalysis or H~O illlP-ius anal)j wn-i uddint(1 thl eharalteliti(s of till liquid with pleeipitated ruhber or resiu in HI~P(ll-ioll n ren1 on the lpNmiddottroshyphotometel m tololinlPtprfollop(1 it lPgnlal lIlll II~ lxplaiHd on pHgP-I (Sl( figs 11 aIlIIl) Tid made it lloible to outain lEPJOshydlHibll tpnlt nntI (onplt1J1(Jttly till JpqnitPIl tlPgJPP of PJPcljoll
IIWIE(TI 1lt COl~101J)
Jtl thp ItJiPl middotxlwlillltnb hefoJ thtmiddot -1l]YIlIt allll pnmiddotdpitallb had lIptll ptoppJly adjutp(l it l fOllll tIuH till llP or a Ploltiw colloid -wll ltIi1)cJ [ttlJmiddotntl- imlIopl tll lmiddotpro]lIibility of the lPlllt JmUkllly ()Ilt 111 U lput lUlU illlihumiddot tOJllPOlUtl tpHd liglyeol teltlut( - llpanlItly IllmiddotlfP(] to lit til I1m t IHflll lImnnmiddott nftlr tlH filial prOIptlllll WtlP dlvPllill1 tlll 11lIlpfit (If thtmiddot [llltlltin lollohl wa Hot 0 natlv I1l(lhmiddotd III rlumiddot Ia- of tmiddot ill tllmiddottJmillaritlu it b [1 hmiddotjlmiddot til IIpoundgt Ir llH1 It liltr ill-llImiddottiT Ina lll ptlPII by it U( in ruhhfl mmly j 11If dtmiddottail fOJ tltt lllllmtlllll If thl plot pet in nlloid ~llntill tltlmiddotlImiddotmiddotlttlatiflll lIOlllllllhtiPI1 are iPllllll page
liTFHFEHliG COIOf
(hi II tht lllail 11111111111 that had til ill -111111 II urklll) om tlH method fot lublJtt tlIlO1 rpir- nlalv~i in plaut llllpll- wa ttl (lilll~ inare tIte (gt1[01 till to tIll ptP-PlHt f xi [aIWIIII- 111 TIlt amount of (olor varip from lUllIt tn -amp ]pplwHlI nlt rhmiddot lt IIf thE Hl(ltllial tllP part of till plllIt -lI11lhmiddot(l tilt hi-tlllY f tlll plaut mtteshyrial ~ub-lltInent to Itlllmiddotnmiddot-rill lliI 1011middotly OrllPI Inlw
In ruhlwr lrtl-i I Iii 1101 au Itmiddot 1Iplll11l by 111[ I--r ratmiddottilt thE -lllll]t with uptoIw or 1middotmiddotlIll-ol - wIdell [llllol- rlll loillriu nutttel autI thtmiddot lpill- Thi- howmiddotvt n(tnll- til lXtla -11gt1 ilt prlJ~edun) In lP-ill ltluay-i nllHufldy tlW[t j 11 1 1IO(PIlln fill the 11shylImya of hlulophyll Hwl rIlI-r middotIOII IHlttlmiddotJ dlH lUtl~ In plltIH withoUt alo aiftIriL till nmiddot ulttrll
111 pllIbIll1l Wi tilmiddotr hId h It-ImiddottHI tht Pltlpll 1 hlitlt lilt tlw tulllWlli tollImiddot uIwltllIIntut -lltUIhorlllllltll 1111 tIll tlettlllliIttwr IIf t 111 lWlrl-Uamiddot of bdt tl11blLlittUhmiddot r [1 tItmiddot preshyj
lipitatifll 1lJ llllllWI atbull 1iI- in III -1nrmiddottIi fHlttalldh nlrillU~ amount rf middotlorilig lIUlttll Iii lhll of ih lltmiddottllllhottohttt~l l~ol()r infrtl Hm II upd 1 rwmiddot tld~middottilmiddottll PlllItlhi~ f it j proYitiltl with tIll lilP--UlY tU(jlIdlllIlml tIltmiddotmiddot lllklllUIlI
EIECTIol OF 1 [EGTH~
-Ptfmiddott ral tracilull ru~lI gtIll fr 1 nllb t ~xtltd 1 lIlt-th vI iobmy1 ketommiddot lWtl rill [ Ixt lttltt ll UttollylaIiIitt1l11I1t~ ~-I itoiu YtHil)u~ typp of ~IHaylllt f i lItmiddot art hraquoil ill fio1ll1 ~l Th~ lp-nlt fill I11oohl uio[1t ttl willlr til tltN- fur rht IUiXtIUt iwliutll
100
22 TECHNICAL BULLErIN 920 U S DEP1
90 bull eo
I shyz 70LLI 0 a LLI a 60
LLI 0 50 z
a ENTIRE 2-MONTH-OLD PLANTS~ 40 b ROOTS AND BRANCHES OF ~ 3-TO 4-YEAR-OLD PLANTSen z WITH LEAVES REMOVED ex 30 a C CURRENT-SEASON GROWTH OF l- )-TO 4-YEAR-OLD PLANTS
20 WITH LEAVES REMOVED
d LEAVES FROM 3-TO 4-VEAR-OLD PLANTS
10 A
0
a Cd 100
b bull
10
80
I-Z 70LLI 0 a LLI 60a
LLI 0 50 z ex I shy 40 ~ en z ltI 30 a I shy
20
10 B
o~__~__~__~~--~--~--~--~----~--~--~ bull350 400 450 500 550 600 650 700 750 BOO 850
WAVE LENGTH lM~)
FJGcm O-Sll((middotlllll tramaniW1IHl (mrpS f(JI (xlmll 11011 n J1ll of jlta)nle tissur ill n 2--m1 Y011111P of (A) Illrthyl ji1I1J1ltsl krtonp 1111(1 (ll) nt(middottQnyla(umiddot tClIc-C(l1osuln a-i
bull
bull
bull
RAPID PHOTOlIElRIC DETEH-UXATroX OF ntBHEIl AXD HEstxs 23
ThE dula Pl(S(l1t(lltl indi(ntp Ihut 101 Illp ulimls llHthyl liohutyl htOlIl (lxtrHts (lI(I r(dolls of Il1Hxi11111III nigtol]gttioll wiH1I all (is-lIb 11 cOllsic1(]((l n1( blhn(11 wn ( ItIl( Its lIO to () I1It~ nlid Ii to Iii mJL
WhllNIS tlw I(gions of 1middottnL(s( light 1lnlllittamp al(l lgtPlW(PIl wan Ipllgtltsnr) to Ii nllt jW) 1I1JL nlld alio Silllill1l 111l1b (n SI(lIlId 101 nc(ton ]altmiddot(fmiddotollp-(llloolp ~ pxt Ill of 11a 1111 t illl TIl( (1101 du( to lolo ill tlw litlltitl a 1Il1 lullll(I tH lPill- hanmiddot bpllI PI(_ ipitated ma he 1((I1((d to fltI ynbhing poillt II ph( illg OJ illshylmiddotJall(( WIWp balld nhm ()) IIIJ1bullbull[1I111 lxjlPIitllll1b Illln -h()1 that Ih( lIIot uilahl( WHYI lHlIJ fOI 1-1 ill 1l11J1l(I HIH11Pill- illllllrsi i-in till IlPighl)()lllll()(l of ~llIl1lt bull
bull UIlIilHlIy of n typhn] lXPllillllllt to )10 l1iP(tiP ((JIlllo( of (ItOIS dul to lOIOl in 1llblnI Hnd Iill xtnumiddott 11(11 IIIIolp t jUl i p1llelll((l ill tub]lL Till llhlllt- 1tpIO]II Hnd ((llll~()h whit-h UI(I ](]Hllilltl n 1I01lllIhb1 01(111 lxt 11111 IIll 1llll)1 nmtp[in I and )(middotills Tid IIlnkl it poiblp nftlI tlIp uplll1tillll or tlll o1PIl( (0 [niH lip 1Iidl1p~ of lI111 11111(( ill lit ll11l1)[1 (llnlIb nlld Ihll
Sl(ll n ol1lliOI with tllP olnl IJllt illiollt HIl Iltlllll llllI (Ill ltllthpl prpipitnnt j Ihll1 nddld OUI ha a lIilPt lP( of till lIiciPlw of WH( lllIgth 7) lUI- ill llilllillatiu (nnl till tll Ixtll1I101l ()lll~
Tuu tmiddot-Elilll IJl flrldillY 11-1111 lrlllI IjfJI til islII 1 1(1 ([rllt IIIIIJIlIr JiIlIt~ if 1Il( Ihll 111111 k til I III Ilrln I 1Intd tf 11111 JiSf fill I I II I tIII Ilf Iilltl 1f1JlIIillII1f I Till 1[ 1 IId 1 (I (middotIt 11111 (I1I1iI1 1lf1IWtlfJlIIllfflr p middottrllhIJ11 II J III 7IImiddotIa 111 111 lilt jJIp 111 wilTII
t~t tnVIli~ ~nn r kn t~ i tmiddot ~~l Jr 1middotmt ltlTt
HmiddotOtt ~I~ lin t I ~ 1 t~~l ~qrmiddotthtmiddotrtwb
Hult-middottltlru t T Hw ullut rHtt~ r II I ~ PH~lllt
A~tmiddottHHjmiddott~rjd rl ~gtllh 1 tn~th~ ~ ~ middotI lt~ b w bull hmiddotth~ 1i~lIhun 1 Ii tnl Illd1 -11lt1(11i lullI lUI tJl ll~ t1~11n( I Ihan1li flfttIJir Ult I Uuhtltt ahuul l(hmiddottHmiddot~t trv r fti HIt lftbyl tlonhUt)1 k_hIl( 2 m~ fmiddotf tuhlHmiddotr In mlth~ llmiddotlf- 1 t r
t r_~ t j
Arhlitlltd ~llIIDHl NcWitn1 ( Ar-(lt()nc~middotttrrtrt ritJJI~ -Iu nllJtl4-middotr
ACtmiddottflnp fmiddotxtrn( ~ T-P511ftf tn mtmiddotth~ 1 ~difmiddotut~ kdn 2 nltt ulruhhtr in Un-tIl lltbu )J~IYt
rUth(Hl~hltlft HhubU
Illlh(I(t tttUtUt hUbtl til J ~jlitl(J Hilllll trtIIImiddotjtl1ll
(UShl I ~tlO wHllolH rulh r (middot1111$0]( J~rru t t )lthyl 15bullbull1middot1101 klll1l
Ili( UHUicbcul ~((i1rUtl ~ulu1iin 1middot lIUIll Ilti lrllltlllt I Ruhhr llt1thuI r1 -1 Irld
ltlt1111Sh 2 nuz f)rruhl~rm nlith~l tu- h f nt nil~middothgt(H] tlrlftmiddot 9lUtirtl middot1 1
rlcltfl( H(l dnllltml it
(IISllhH~rI( Iultruhtr CII05 1v ltTlft I 2 UI~r ublwr In llldh I hlt~1 11) lgtjdvr(llsl~9rlltmiddot middotlmin ~ I~ gt AIHItilltl no IrttipHallr iI
~ Bbnk 10ol m(thyl i~tmiddotut~i kdHn H 1 m1 j~~ l1rH-t lt~tlfltmiddotn sf n it ll HltlMjftr~nol O2~mlJ ~U~1o-ulp ti~tW -xtra~middotl(lt1 ltt 411 ml bull ie f Ct- kft rt t~ tirattJ middott ill r u l1kn ttJt
in metltl isobutyl kNqnf nn~i mljp ur tmiddotmiddot ~oml ~urr tttl i t w ltJj1JH kt 4t 3 nlank 1 mL((l1t~rthmiddot(middot mI mttr~ ~but a kmiddot tmiddotc d 11 ~ gtli~b~ hifIAft- fl~ lL lnti 149
ml8(dlfilll BO bull 02 gm guayule U$Stl(middot xUlClt-l tf(h tft wI n nmiddotmiddotmiddotlgt 1 lznt on tmiddot ~Jt r~1 ~~u~~ H~ iI~ thT
24 l$CHNlQAL BULLETlN l20l S DJltJPT OF AGHl(CLlOHJltJ
In table a is pl(sentc(l such c1il((t edlt1tIHC showing that thc (0101 Ixtrnetccl from guaYIIle tisslIe wit h II(P(OIl( n nd (pl1oso[yc is cll(div(ly sCIe(nec1 out by the s(lp(tion or wnw length )0 miL Oil t1w SI)((IOshyphotonwtpl This tnb]p all-HI ihos thai thl Juhlwl altl(l((1 (nn IJl quall shytitntivcly 1(I(()(Ipltl in tIlt PI(ilIH( or Ih (o]OIplnwPIials and Illsins and tlmt Iuhb(l WtlS nppnlllltly 1I0t (xtltI(((1 110111 11l glll1I1l lisslIt b~ tlHSP SOhlllts Thls( ((suIts ginmiddot (OliIHillg (idJt(( that t Iw IISI of waYl llngth i)ll 1Il) OIl till SppdTophot OIllltPI ii t hl 1101(1 p(oshy(ellule in photolllliTie IlIlalysis of luhhlI OJ l(sin-
SELEGTIO- OF )IOiOCUHO)IAIIC ItIIm ((1111110
On th( basis of th( IPHIlb shoWIl in tabl(l 1 al hlllpls (1( IIln(lp to SPCtl lC the PIO]Wl 11101lO(lIOl1ln til Ii ltlJ ((lIllIJi nIl ions 10 llIiOlS (oIOlimet(Is 111(gt 7W-Ill~ filtpl flllnhwd 101 til( I1~lI1l photoshyplpct1i( (o]oriJl1ltll fol which Ill( (hlll(IlIiitit~ oj t hl Ilda he light ilUIlBlIIhiSioll (t) elll nn -hO11 ill fig1lle 10 iws satlsfa(lolY IPshysultl 111( iiO-mL HitlI olllhintioll 101 whkh ttp (middotIatinmiddot light tlnnsmission (ullmiddotis a 1-0 showlI ill figllll (I is -nthdnlto1 hut this is not stnlHlnld NtllipmPlli
Up to fhl PlPHllt lIS(middotflll pound11((1 (ulllbinntions jn lltl iOO-I11L Iunge hayc nol bllll SlClIlld 101 lhp Klpt 1-1I1l1I11PISOIl (olOlinwtll bu fnltlwl nttCl1lpti 1( )(illg IlIHd
TJIpound OF ST~lmW AFTEH HIIJ1EII Oil HHSIS rlll~CIIITTI(J
~ considl1ltiol1 of ttp lillll of Inlllling af((1 plpeipital ion of 111gt)(1
01 l(sinSTlOIll ollltionis impoltant J(jl~ thC1HI(Plltngp of light IInIlSshy
11 rshy10 f shy
09 f shy ~750 Mil- DOMINANTI
~ 08 cshy I WAVE LENGTH z
I III III i O7 - I III
~06 - 05 shyw
a
Igti= 04 - 720 Mp DOMINANT ct WAVE LENGTH- ~ 03shy
02 f shy
01 t shy 1)O~~~gt~- J 600 700 800 900
WAVE LENGTH (Mp
bull
bull
bullFIGlRt IO- COJllPIUlItiw ~IW(middottltll tlnIlRlllii-lion (II (IllP( 101 1i11(1 olllhinulloll
with dominllnl Il(lllllgths at 720 and 7iO lUi
bull
bull
bull
HAPlD PHQTQlfE1IUC JjETER~lINATION OF Rnmrm AND HEtiINi 25
mitted (spertrophotoll1eleL lCuding-) Ol light (1 (tClcrl (phOlOshyJluol01l1et(L lcndillg~) i~ StlhjNl to (hangl
]fjt~l1le 11 and l~ show that ill til( (asc ot tJaugtIllitteltllight llJHC th~ (x[llliHlllIlnl (oIHlitiOllS tllpl j lilst n dtlln-e ill Pll~(lltngl or UllllslllittnlH( follrnY(l by It ptJiml of lClntin stability with only sliuht (1111 tHn- a f(Pl a lIt1ll1btJ of minutes The light t UIllllitblllll t l(1 ill(Iln~(s This lIIay IJP llllllJltlli7P(ll1 ffl II ow 1Ilt )( f(( darI oliIII tIIlIlNlIlitt(IIIlfJIIlh (iditilIiid Ilil1 pllIipintnl )uoshyIn Of ( 8inx in (~f1( I~iUII i~ Ild stahl I 11 itlll If 1inl nh prlshyilli(ioll of 11l1d(1 II IJIX f) jllIli II (fJJltfiIIlilty slllMI IIriot 1) IIIPldUnl1i tll(I1I rllltltilJl oj tJi~ Jlt jiot IUN ilUf Jxl1 will tIt( tOWI IItlllilil I 1llIlllblJIol I ill I~11l11111 d ill till ifjuids JjOI scnttplltl light 011 till phololltHJIOIl1lttl till dilPCt ion 01 elangl b tlw IPrfIi (If that illrli(atPll rOl tlulll1Jittp(lliuht It Itlll b( llluliJr I-(Pll that if l(middotndlnJ- IIIP mad n itl I t lIP ~()ll1d()lb lpalll this pllioJ of nmiddotlatirp tuigtility tllP llLot tIOllt thi Olll(P (nil bl IPdUCld to tIl lltini III 11 Ill TIll l~adiltg (illH~ bbll Oil tlHl datn rUl lublwls and llsinlt Illl ginll ill tnhh
50 r----------------------------------------------- f shyZ
~ 40 ~----~W~A~V~E~LE~N~G~T~H~7~5~0~M~P~~~~ ~ --------------------=-=-= ~ 30 f- WAVE LENGTH 540 M~ _z _____ ___ -=- __ _ ~ ------shyt ~_=---=-=--I GUAYULEIII 20 -Z HEVEA ltt II KOK-SAGHYZ f shy
4 6 8 10 12 14 (6 18 20 22 24 26 28 30 STANDING TIME (MINUTES)
FIlirtn 11 Emmiddot of wav hll~rh Il li~ltr tlall~lIIit1alHl aftI IUIlItHt -Imlli lug 111m for guaynh llmiddotn 011111 middotiolIlJh~z 1111111 llijlitul1 flolll 1lHlh~ll1Jllryl k11II11l ~(lilltlll h~ lwitlitll 111Inu1 111l~1It1 2)1111 o1U11111 (Helillins on (illllun tlunhll IlIIJlllw]ntllW111 lutl(I[lholtllllltlt with ijUjt Wlnl IHI Ilf1 I
11 EFFEGT OF Hbli 1 -()JXT10~
Tilt lnblwl ~()h(llh pxtnl( till IPillgt ubo It 1m nllu1- bellt -~atea thut ~lll 11-111- tUP olnbhmiddot ill middottIIlIlOl ~1It tlWIIJI( my U)t PIl (tlIHatcl WIth tl1l lullh(t I tahle lJ 1hln 1- -1111 tIll (llllstlOll of nny p()~iblt tITptt of XtIIl11 diflp]lws ill ((JlllPllttUliollS of 1l-in lil lolutioll alollJ with till 1lIltbpl TIU data ill wbh +ho on tIl( hn~is of (olorilllPill ladillU thaI tll( IIUOIl1t of lnbbll Plllipirntld 110111 Ilwthyl olnlld kptOlll olntioll IJ 1li-jHlllnt 1l)04 in 1-llltlIllt ethallol)- not amlll hy thl llllNlI(l of llvin aU1ouut of llins inolution bull
-----
26 rECHNICAL BULLEfiN 920 U S DEPl OF AGRICULlUHE
100
90
80(I) C)
z Ci 70 UI a 0 60 a ~ UI ~ 500 ~ 0 I Il 40
30
A 20
0
100
90
(I) 80 C)
z Ci 70 UI a 0
60a ~ UI E 0 50 ~ 0 I Il
4-0
30
B 20
0
--
--shy ---shy---
2 4 6 6 10 12 14 16
---shy= ~ ~ shy
-
2
025 05
10
15
20
25 -30
35 40
SO
-60
=70 80
16 20 2224 26 26 30
OS
- 10
IS
20
2S
30
35 40
-50
-60 -70 -80
bull MGPE 25-ML
VOLUME
bull
MGPER 25-ML VOLUME
Florm 12-EtTld (If till1l or Slllldill~ 011 light transmittallce (01 (A) gUllyulc lnUIl(I plccipitllitd frOIll llltt h~l isobutyl Ielollt solution Ily neidilic(l ethanul bull null (B) gUllyule ll~illii pre(ipitated flom aeltoll~lllcetOlll-Cl])osolY( 3-7 solushy11011 by H(illilip(i l1U (HPlldillg~ nt -lIlillult Ifllpluls 011 Evelyn photoelectric colorimellr with jU-lllp tlllll alit U-1I11 npN(lle spp also table 2)
bull
bull
RAPID PI-IOlOMEllUC DElEnMINAlION OF RUBBER AND RESINS 27
TADIbullbull ] 4-ReZation of amiddotmount of middottbber pleeipitate(Z Oln metltlIL isobutyl ketone 80lutions by OS-pereent H 2SO in 95-pere(lIIt ethanol to umollnt of resin8 udde(l U8 indivute(Z by colorimetrio readinU8
(Rubber ami resins cnlculntcd on bnsis of amounts in 5middotml ullquuts of extract from 02 gm of tissue in a 2fllll olumo( bull
Hubucl r~cocrell whcll rcsins nddcd as IndIcated Htbbor al1dcd (pllcollt) ---shy
__________bull_________ ~_12rpcrc~15011crccllt 7511crccnt IOOpcrcent
PerCtllt ercellt Percellt Percellt Percent o o o o o) 50 250 263 252 25000 500 500 500 500 700 750 750 751 749
1200 1250 1250 1250 1250
EXTRACTION TEMPEHATURE AND TIME
Typical experiments to detllmine the time required to secure maxishymum extmction of rubber und ltsills at 115deg U Ilre sUlIlmarized in figule 13 the solvents used-methyl isobutyl ketone for rubber anrl Ilcetonylacetone-cellosolve 3-7 for resins extraction-are very eflicicnt since under the conditions indicttted maximum values were secured after 30 minutes of ext1llction The most eflicient liquid for the bath (lig 1) used in extrtlcting rubber or resins is ~ high-grade cylinder oil (S A E ~O) The sand bath and such liquids as glycerol have proved unsatisfactory
RUBBER AND RESINS STANDARDS
According to the National BULeau of Standards 1-_ lhclc Is no gellcrnlly recoglllz(d standard lIIutcrlul [ior II rubber standard] The rubber hydroCllrbon ill llifferent samples of conmlcrciul smoked sheet or pale crepe from heclI pluntlltions nries from l~ 10 04 llercent of the totul nutletmiddot the most 11Ioruble conditions Of preparation
McPherson () has described a procedure for the pLeparation of pure heve~ (Hevea brasiliensis (H B K) MueH Arg) rubber from crude rubber or latex In the absence howevcr of ~ generally recogshyn12ed stalldard for rubber hydlQcllrbon [caoutchouc (CnHUs) xJ the standard adopted was that of the relnthely pure product secured from gunyule tissue txtractiotl nccording to the Spence-CaldweU method (5) or the motlified PIOCCdUlU of Hohnes lind Haasis (p 2) The details for constructing the calibration CULes are given on page 10 Standard rubber samples apparenl-]y can be stored for a long timc under the conditions des(libed on page 10 The duplicate colorimetric lendings for glULyule rubber newly extracted by the modified SpenceshyCaldwell method were ()J2 ench as compared with US) each for the sample extracted by the same method but stored 1 years In each case colorimeter rcadinllS were made on mixtures containing 2 mg of rubber in It 25-1111 Yolume
The selection of tt suitable standurd for guayule resins presents some dilliculties Tll(~ acetone extract of gUllyult estimated on (l gravishymetric busis~ for instance proved to be variable depending on the type of tissue sampled or season of sumpling because such fractions as
COllllllunlcntion dul(lt1 Octohtr 22 11H3
28 QECHNICAL BULLEQIN 920 U S DEPT OF AGRICTTIIlURE
16~==========================115 shy
14 bulli= 13 z ~ 12
ffi II Q
10 c w 9a w
8gto () 7w a
6a w
5en III ) 4 a
3
2
A 00 5 10 20 30 60 90
14~------------------------------------------- bull13
i= 12 z w II ()
a 10 w Q
9 c w 8 a w 7gt o () 6 w a 5 If)
z 4 If)
w 3 a
2
o+B~~__~__~____________~__________~ 5 10 20 30 60 90
HEATING TIME (111 NUTES)
lllGUltE 13-lDffect of time o( lICntillg O2-gm samples of gunynle tissue with solYlIt nt llfio C on lo(OVl)ry of lllhlJer alld 1Isim Lt HlIhblL extracted with methyl isohntyllwtone B resins Cxtll1cted with aCftonyla(etonc-cellosolve 3-7 bull
chlorophyll are weighed along with the resins in the acetone extruct but are not estimated by the present photometric method (fig 0) 1he use of a diffeJent stanclttrd waS therefore indicated
bull
bull
bull
RAPID PHOTOMETRIC DETERMINATION OF HUBBIm AND HESINS 29
The resins standard selected is based on n relatively pure source of resins the rcsinous exudnte 011 the stems of guuyule plants IJldimishynary expeliments with the resi nouS cxuclate from diffcrellt gllayu Ie strains of various ages indicatc nHlt there is little YaLiation in this subshystance on the basis of Colorimct(r readings 011 2-mg aliqllots of 01shypercent solution in It 2i-ml volume (tabl( li) Expelilll(lnts have shown that the air-dried (xuclate contains 3RtOH p(Ic(nt of -volatile matter This material is l(latiyt~ly stablp ill (OlllpoBition and is npshypurpntly on ly slight ly hygroBcopic as shoWIl ill Ia bl(1 1 Tlrp Ipsinolls exudate may be jJleplpd in two wayi-i fl liSP as a stallClHld-(l) the clpan exudate is clripd iol Ghouls at ()1deg C at W indlPs of a(lIum Hnd aftclbCinOglOund ill a molfalis 1)I(spI((I intn airtight COllilinel OL
(2) tllP Cx7lclate is clissolllt1 ill a(lhllll and filtplpd PlactieaJlyall of the acetm1l is thpn lYapolntwl olt OPI a stlam or atCt hath and Ow residue is dripd ground an(( PI(sPIld as ill tllp fin lllethocl Tlwse two prepalHtlolls a1( (ompalpd in ta hlp ) 111( (((tails fOl ~t()lil1g the resins standald and (onstlllcting the calibration CUITPS alc given Oil page ]2
lAIIIg fi-CUIIIllrsoi (lJ lIr-dr(1I IIIIi 1((11 II II-()I-tr((l l(sil~ 11111111(8 of I II 1111Ie
[Colorimetric rrndill~s 011 1~I11 phulll(Iclrie eolorillJct[lr with i~()middotmll (100- to iiOIIIIl) fillcr [lnd 5-1111 lIperture preeipitantl part ofO5middotPIrctllt 10 to 5 paris of IIOj
nupliclllc(oloritwt([
nIl(lin~s (hIlSlcAg~ ofSlmillXo JrNliltlCllt of fPsiJI$ L1Xtlrlntp on 2 IIIg ofplanls fllsins (XIHIIlt~Jwr 25-1111 vol
tII1(1) 1
leflTs Various _ bull ____ bullbullbullbull 3-9 Colll)Josiltrlairmiddotltlricfl bullbullbull nf)2 002
])0____ bullbullbull _bull __ _ bullbull ~-l Composilld (ri d at n5 C in aUmiddotimh lWUUllJ for l (jOuj(ja hours])0______ bullbullbull __ bull ___ bull 3-0 COJIlpositld disso]NI in neptolll f1l1erNl fl(lf()ll( GGO i(jO (Ivaporntld olT OV(1r Stpl1l11 halh TesidlH drl(ld I1t fi5deg ( ill anmiddotinch VIl(Unlll for 0 houlS bull
middot106 __ bullbull _ Jir~c1rild_~_~_ _~_ ~_~ _ ~ ____ _ __ _ OUu GOifina_~ ~ _ ~~_~ ___ _ _fln~ ~~ ~ ___ ~ __ 6(imiddotI tiliA H)[_ ltlu bullbull i18 tisSflOabullbullbullbull__ bullbullbullbullbullbullbullbull lt10bullbullbull _ tillO llitO406__ bullbull __ bullbull __ bull __ __ lt10_ Utl2 fon591_ fo__ bull liGa oOa 406bullbull _ __ lt10bullbullbull_ li5S OM
j Ph( vnluls in Uw Inst COIUIIlIl indieatp thnt gunyulp fesinous (IIHlnt( wlwtlwr dfircl hi Yn(tlLJ1l1 wilh L~ perc(nt loss of volntllt wutl pr or tWl c1rild giVPd npproxil1lnh1ly t Iw snllw colorinwtCr rNHiing- 011 till busis of aliquot~ cOlllniuiug 2 IJI~ of flsillS lXIHlntp l)tIf 25-mI volultl( Ihil- illdicate~ thl11 Uw UITW IJ1flS~ of olnshytile mntl(f prt~(iJlitnt(d gins npproxilllntlly Uw $1II1l (oiOfirnl1tlf ftudiTlJs ns tho ftsidtw A pnlill1jllaf~middot (XIlltrinllnt indicutls thlli th VUllltill muller l(lIlSists of thl Ilrplne oil fmcl ion I5-(1Il gtnplls or rlsitlOtlS (lxudntll gnvll by stPll1U distillation nn Uefllgl of 011111 of jl(lfPlIW oil with npproximHte tilllsity (If OHIi lind lhus rrprlsll1ll( IlPIJroximllt(I~ 01 Jerccllt Of t he original weight 1hls lllrClnlage complrcs wllh 38 llltrC(ntlost by drvinI( in IICllnllJ
aSplusmnUH perceilt or orlginlll weightlosl
The wailnble illfolJllntioll on tlH (ow-JitlPllts of the gunYllle r(~shyillOllS exudate alld tl1( HeetOlIP ext act of gaylp ti~slw is sllIllmarized in this paragraph lYalttI (u) alld also Hangcn-Slllit lind his coworkshyers 16 reported that 20 percent of the resinolls exudate from gUltyulc stems is parthenyl cinnamaie (CHuOH=CHC020 11JI2r) Steam disshy
15 (OIlIJIIIIUicatioll flom A T Haai(II~l11it llId (0011(11 Calif0111 ill Tnfiitnte of Tccllllology Past(IlIJI Jhps( wOlken al Htud~ing the COTlHlitlllllts of the acetone extract and other conlltituellis of guuyule
30 TECHNICAL BULLETIN 920 U S DEPT OF AGRICULTURE
tillation of similar resinous exudate in the writers laborntory has yielded approximately 4 percent of the whole as the telmiddotpene oir fracshytion Haagen-Smit and his eoorktrs nportec1 thttt about 25 percent of the acetone extract from guayule branches is parthenyl cinnamate and 6 percent of the bark (ltortpamp-phlotm) extraet is parthenyl cinshynamate These workers fm-thcI reported that 25 lwletnt of the nc(shytone extract frolll bLllllches is a compound with the tlI1pilicaL formula CBoH400a 1 percent is a compound llwltillg at 2P to 2T5deg C and 1 percent of the extract from the ]eav(s is tl (olllpoulld nwlting at 100
to 1710 1Valtei (6) reported that 3 to -l perc(nt of the tI(eton( txtract
of leaves and flowering StPIllS of guayulc eonsists of waxlike substances soluble in olgallic soln~nts but insoluble in at(l and (on(ent1llted H 2S04 The flactions mentioned on the basis of (onHLTutle esti shymates of amoullts actually isolated tlecoullted for about H ptIcent of the totalncetollt~ so]ubles extracttd from tll( guuYllle 11 rub The other constituents ltlilaill to be i(](ntifi(d
RUBBER AND RESINS CALIBHATION CVHES
Typical culibndioll Clllves iol Iuhbpl and I(sins bas(d 011 (ldtLminttshytions made nccoLdillg to the plocCdmC outlin(d 011 pages middotb to 1G arc shown in figulPS 5 and 1+ The spCdlopliotoll1lttL en (OIOIjlllctCI readings are plottCd on s(lIlilogalitllllliC pappi ag-ail1st (Il 11IbblI (011shy
100 ~ 90
80 ~ 70 ~
z 1amp1 0 II 1amp1 IL
1amp1 0 Z
60
50
40 ~ltI 30 ~ en z ~ ltI II ~ 20 C) ~ oJ
10 o 2 3 4 5 6 7 8 9 10
RU8BER IN 25-ML VOLUME (MG)
bull
bull
bull FI(lURE 14--Ctlihration curve fotmiddot gllftYlIlc lubb01 (Hct(lings Oil COIPIIHlII tlOl1hl(
monochromator SlCClrophotolllet(r with 7fiO-11IL Illtel alld Hllp Wll ( IHlll()
bull
bull
bull
RAPID PHOTOMETRIC DETE~MINATION OF RUBBER AND RESINS 3]
centrations From a casual inspection of these CUlTes it would appeltr that Beers law does not hold Actual tests indicitted that Beers law was applicable only within a narrow range in the upper portion of the curves The analyticlil results on the basis of photornetric readings nre therefore calculated by direct reference to calibration curves or from reference tables of equivalent values bllscd on the cnlibllltion curves
Calibration curves for kok-saghyz alld heyea lI11tulltl rubbers and Buna S (GR-S Chem Gum IV Goodyear) and butyl (GR-I Standshyard Oil Co Protoc) sYJlthetic rubbers are hOWllil1 figure 15 The samples of kok-saghyz rubber were furnished by the Diyision of Rubshy
100
90 ~I) ()
z 0
1amp1 a
~ a
80
70
60
s 1amp1 ~ ~ 0 ~ KOj-SAGHYZ 0 l Il
50
HEVEA~ ~
40
100
90
~ 0 80z Q 70a Co)
a 60 ~ 0 0 x 50Il
40 ~----~~----~------~------~------~--~ o 2 3 4 5
RUBBER IN 25-ML VOLUME(MG)
FmUIlE 15-CaJiblation curves fOl kok-snghyz h(YCII Bunn S lind butyl rubb~ls (Readings on gy((yn photoelectric colorimeter with i20-lIIp filtpl and 6-ml aperture)
32 TECHNICAl BUIJLETIN [)20) 1 S DEP1 OF AGrnCUIlfURE
Iwt Plant JIl(I~t ignlioll of thi BlII(un and (1( l))(parcd according to 11( SPltI1((-Culd (]] (6) PIO(((lllll Hlpt pal( CLPPe was (xtmch(L with acetone blI()Ieit W 1I(gt(11l a ttnlldal(l
SEXSlllVllY Ol~ llETJIonS
By lip pIO((l(II11P olltlillP(l 011 ]Hlg( +n Iowa (lOOl IIIg (11 1111i(l0shygmm (gHlllllla) of 1hblI ill a 2)1111 yoltll1ll (all )(gt dltpltld Oil tltl Col(man (lohlP mOIlWhlOl1lHlOl l-I)((t 101 l1lOt 0111 ci( I ill1ilnlly 001 mg of Iublwr ill a 2J-1ll1 n]ulllP Illay bl Ilad Oil till EnI)1I photoshyllectlie (O]oLillllt(I Thll ya lllll- 011 tilt IHl-i- (J I (xl ad iOI1 fmlll 02 gill of til-lI tH(JI(lillg to tllP -lllndal(l jll()(pdull 1(PIPStlIt IlO()2J tlnd 002) P(IT(lIt of llIbl1ll IPI)(((inly bull1t1lollgh -lI1t low allils can be d((d(middot(1 il lIoullt1 Ill IPtllizpd thnt till PIIOl ill PlI(Plltng( or tll( al110unt dltlIllIilll(J i ltlatlpl high ill tili PIY lo Itlllgl 111 aetllllllladie(middot Ill( lopl lillliL 111)(1(1 lIw (ollllil ions of tlil ]lI()(lltlIIIl u ol1tlinpd ipt at l11 11I1 or 1111gt11(1 illt i-1ll1 Ollllll IlPIPltPlltillg 01 p(gtl(pnt of JllUiJtL un tlll 1Hli or (xlla ion rlOI11 II rlll of tisSIll
EIlIlOH COSIIlIHIIO
In Oldpl to H(IIp ill )1lHtPltt pl((iioll illlpIi1I- it i lH((SSHI to slnlldHIdiz(i rigidly 111( Pl()((dlll( 0 illdi(ntpd Oil pnglt- - to J( If lids i dOlH tlip lXIHlinwnlal PIIll is t(middotdllld 10 n ndninlllill
Illlt pl(iioll of (hI ]lIPPllt 1IHllwd Oil til basi of ]llllP llIllJt1 alld Ipsinssollltions call hI jlldgl(J 110111 figllll Hi lileh lio- til HPIlIgl d(intioll oft -illgIP lI1lnSIlIlIIIlnt in lHi((lltagl of Ill( alllOllllt 01 Illhshy1)() 01 lpsins d((PI1I1 iJlld TIl( (1101 PlI(Plltaglt H1( gi (1 101 OJ) to
RUBBER IN 25-ML VOLUMEMG) 004 01 02 03 04
i= I I IZCtOW
fbA ICtU CtCt WW a
01 02 03 04 05 06 07 08 09 100 = RUBBER (PERCENT)
RUBBER IN 25-ML VOLUME (MG) 10 20 30
~ I CtZ
bBOw Ctu CtCt Ww o I~
010 50 100 150 200 250 RUBBER (PERCENT)
RESINS IN 25-ML VOLUME(MG) 10__ __3-0_ 40 50 60 70 60 90 100--_-- 2_-0
Ct~ -r- 1 I OZ
WCt UCt b C wCtW
a o I I 150 250
RESINS (PERCENT) o 10 50 100 200
bllI 1tI W-Yllnl dtd1 ioll I I 11l1 11IlI11 1(111(11 1 III Plll- IlIIIlol1 01 IIim~
bull
bull
bull solution Il basis J o golH of tiSSII (JlILCl-nt (11(11) for (~I) (l)1 til O 1I1
of luhllpl lin 1 III I (I Ill of lUhlJPl nllll laquo I J to 111 nlg of IlSlllgt (Itllillgs on ]iYllyu pllolwh-llrk CO[IJlilll(-(PI with nOHIP Iiltlr lIntl U-lIll allcrture)
RAPID PHOTOlJElRIC DELEHlllNAllON Cn HUBBER AND H1~SINS 33
10 mg of rubber anel1 to 10 mg of resins in a gJ-m1 yolumC For
bull
bull
bull
comparative ptuposes the leslllts arc also calculated on the basis oJvershycentage rubber OL tltsills in 02 gllI of tissul As WOlllL be expcet(d the error increases sOIlHgthlf for 1(lali nmiddotly low COlHell t1llf iOlls oj rllbbeL or resins The curves in figure 1(j s1l0 that ill til(gt Illlge Ol to 10 pCrshyeent of lubber the elTOI rangts Jroll1 abollt Ll to II) ]IlC(lIt abo(~ this mlllc tIlt (ITOl d(((ts(s to (ollsidlItbly ltmiddotss (han 1 1lICPllt of tlH mllollnt ltl((Lmill(d Hil1lilally in tlH (lISl of l(sins analysis (fig 10) the ltLTor is (onsit1eIubly INS than 1 PlLllnt ill (he lallgp of 11 t~) ~() penPII t
In nil ([lSl of lllhblI alld (sins lx(Inltpd tIOIl1 (issups Ol addcltl to tisslle lxtlads (s(( tabhmiddots (i H) illyolillg ll01P o(lllntiolls the eLI01
is hig]wl thun that indilHtld in figllll ((j Im pUIl Ill )])p I tllllllsins solutlOII
COlllUCIIOXFOH IXSOLl-IlLl~ Ilgsqgt(Jg
111 th( Jllo(pdulP ollllillPd 011 paw I till illsolllhll isSII Ipidll( tflpl (xttlw(ioll is (Ptill tlw lIask l(lll till xtlct i l1wdp up to yoltlllH It is not rOllPllipnt (0 IPt()PI qWlIltitati(Ir III(lw[olH a 11(1 pllooll extlnlfs of guuyull I is-lll alll thl1l main t11l111 up (0 YOIUllllmiddot bpCaUHI sllch all additiollal stltp wottld]) tillll-C(JllS11ll1illg Th( Iogiea nll(gtIshynntin is to mnkp tltl lXtlUCt Llld Ipsidup lip to OllillH in till original flask andi llPSStllY 10 llwlno tl OIIpdioll wlHIl (allIlnting [hc llshy
Hults f(JI [hl oll111lC displupd hy till ins()lllbh llsidll( III it l)picat (IXpednHllt (ollsisting of Jhp lppJiea(iolls if was Iollnd llftt at ~iiO ( 02 gill 01 Iuhhll pillS IPill-fl(( lisslI(gt (lollpdll fot llwistUlC ou basis of dlyillp ut lOW 101 ) llOlll-j (lbp(ld only t~ llllUll voiul11P of OOk7D~- OO(lOO(i Ill of lllthyl bolnl(yl 1lIOll( (lplhlli(al-t(Tnltle sp gl () Ii I ll(Hli (j at ~)) -gtitllP tl1(gt 1It101111( () r t is-lIl xt Iadld j sl1lall til( PlIOI dul to Ill(gt insoll1blp Ip~idll is slllall III [0111 ill( wOtk it (all lJp diIpgal(ll(l
]hcon~lIY OF HllIllgl AiO HESIS AIH)gl) TO EXTlIACI OP
GlYlLE TISSlg
Tnl)ll G L(IHpslntillp (ypi(nl llld(~ SllOS (hat all a plngl of HIOK PlI((nt ot lltl pltl( Ilhl)(l acldpd to tllP Itll h iolJut1 InmiddottcJllP xhnet
of guayulp tiSI1( WllS 1l((PllIl Tlli nllintioll flOlll (olllplpU I((OYshy
PIY i within flll pxp(IiIlHuttllIIOI ~illli]llly fnbll Ii llows thn 1111 llYlIUgl of 1O(1~ ])(I(Pllt of gllllYllII 1(-i1l- add(d to II( (pllosol( (xshytrae of IUllY]l t i~HI Is 1l(oPIPI
THl~ (~ Hf (Off Ill of 1111)( J OJ I~il~ lItfI(( In ~(JI1IJk~ Ilf (111 [lI1Il fI2 lIII
0 tlUfllllit i~~I1
Instrument
---- ----~---- bull shy 1(1
Colemun ruono~ltrOUlllt()r 2t) II sJl~ctroJlhOL()lIIeter with 2tJ I iflllllI wnclength Fetting 21 II nntl 0-1111 WU HI hUJl(L _ L U
Ill 7Evolyn photo~lcclrie (olor JU [ imctcr with iO-llIl filler IV (I
H1 0 t I I
llImiddot lUn WII 1011 HIO Wn mil lUulon
10 JIg1111 IUI ml lUl anh Io aLn 111)_I ) III li lU It 2) deg wn2SU DD
Irl JIll II IIr II US II
1110(1 lULa lUI IlK) IJ WU
I( llI Htl tNI 1(111 2tlNI HI 0 221) lllil t2S 0 1~ 10 1~13
In (I 2117 I
10U 1l(J ~ 4 _H_j ___
9middotJIlJ5 10115 10 00 lUU5 flUU 4li (tl03 9(11)
leIlKl 1l~)5 lOOU l1KIr JOIS un 003 OIl Ii
34 lECHNlCAL BULLErIN 920 U S DEPT OF AGRICULlURE
COMPARISON OF PHOTOMETRIC A1D MODJIoIED SPENCE-CALDWfLL METHODS OF RUBBER ANALYSIS
Guayule samples were analyzed by the photQ111etIic method and by bull the modified Spenc(gt-Cnldwell mcthod The values in table 7 represhyselltativ(I of typical results indieate It -atisfactory dcglpe of conformshyjty between the two methods in thl range of tiSSlHH with llHHC than OJ) percent of rubbtImiddot On the bnsis of the amounts determimd the results in this runge for the plmiddotts(nt lIlcthod ayernge apploxinHltely j percent highcr
~LAIII~ 7-(oIllJl(i~on of lltlllrIic (IIri mOtllinl SJl(II(r-(ulri-wall IIIrtlwrl~ of rlrrlIIillillfl 11)1)(1 COIIrll of UI(III
1 Flowers frllm amiddotmonth-oltl nursery plants
YAIIIATJO- OF SIli(LE DETEnt1NATIONS Fnoll TnEIIllIEAN
Rllbbel (Uall8i8-Thc plcCision of thc pLcsent method when gunyule tissues Hr( nnnlyz((1 for rubber may be j udg(d flom I Ill datil presentcd in table H TIl(se dahl -how that thl pplCPlltag( uriation of single determinatiom from nwan yullles with low standllrd enolS ranges from less than 1 to 4 p(gtrlent
R(8in~ wWlsi-r-s lndi(a((1 011 page ~j he INntlts s((uled hy the present phoolllttric nsins llHt hod are not tliltly (olllpalable with those of the grtLVimetri( ncetol1l-cxtlt1(tioll II1etho(l Thjs made it necesSllry to selc(t another lalibllltion staudud-tlll Ipsinous exullate from gullyule shrub-thut gies relatively COllstlllt photometric readshyings (table 5) The resin (olltents of guayule roots branchcs or leavcs usually ran(~e from about) to 1-1middot pelcellt The ple(ision of the present methotf WhCll gUHyule thslllS lIe analyzed for reins may be judged from the datalHmiddotpscllted ill table 9 1h(se data show that the p(lcelltage variatiun of sillgle lhmiddott(Lminntions iLO11 meun ynlnes with low standard NTOrs rangcs from about 05 to 4 percent
bull
bull
bull
bull
bull
RAPID PHOTOMETHIC DElEruIINAlION OJ RUBBEH AND HESINS 35
IAIILE 8-luriation inclieute rubller (mallSM of [1wIIle tissue bll thc 1111O0Illclc metwII
Vnrlntlon~Ilbher I (rom mean
ierCtnl Percelll ~OU -22 ~ 25 +27 ~ 20 +18 ~UO -22---------1_______ 51110 0G6 bullbullbullbullbullbull _bullbull
10 ro ----=ii41075 -01 1000 +11 1010 +13
rlln HI itil 1l9~ 1_ ___ =-~~~
115511 ~ US -111 III II 1575 -13 115 b tiS -I a 111 h WlU +22IIM-(middot bull 11K -1Ja Illi c 1000 +03 1J5H1 W +l)7 ll1imiddot tl 1575 -13
Mcnn 15951 131
1102-11 21fJ() +21l102-h _ ~~)SO -17 1102-c bullbull 21CO +21n02middotd ~OIiO -26
2 r~plusmn Il~ 21151 261 I -~-------bull---__ _~~_~______l-___--_
1 lhe$ 1111($ I1n (or SlIlIIllltS Stpnnltplr PHrilClld IIrtlrdlng 10 1hr prollIlIlr( OIiIIiIl(o(I on Imgt$ 4 to IC ~tcond nUlI1 hlr r(J)[ltnts stl1ndnnl llrrot of tilt 1I1(1111
1_1l1~ n-J(lri(iot in relli(Upound rpoundsins (lllalIsfs of VIOJII( lixsue b1 the lhomillric lII(lloli
-- ---~--- - __-------- shybull I I I I Varlgttton
_________~___ ~~lu_n_Jl_Q_~~~_____ ______I__~_o~S_J frOID lDean
Percent Percentgt458-1 ~65 +41IWtl-li 130 -a2Hli8c aliO +26S41i8-d bull 130 -32
1(-011 34I10Olifgt __ bullbull __ ~--====
li-9~2n 881) -06 li-9~2-b Si5 o ~HH2middot(middot S i5 -6$-H2middotd 000 +1
8851 054
O i5 +6 9 i5 +6 950 -20 U75 +6
H-liG3o-n bull -1 n-li6~b bull __ _ -IH-IWH +4H-l61511 bull -1
1tmiddottlU
62~-lI __ 62~-b ij24-( bull OH-Ji
(-Ull
I rll(St oluls nre tor separately ~xlrflCled SllllllllCS IlctOrdlug lO procedure outllned ou pages 4 to 10 i Secoud number r~prtgeulS stulldMd error of lIe menn
36 TECHNICAL BULLETIN 920 t ~ DEPT OF A(]RICCLTCRE
ReUUER A~ALYSrS I~ CRCOE-RcuUER PROOCCTS
Sew rapid photometric m(lthod~fol the ddellllinttion of rubber and reii Hi ill uaYllp ti--ut htp lllell pIPHnl pd oil pag( ~l to In A brief H1111111tlY of It similar rnpid llHthod fm 1I1hb~rllnltlysis of u1lulcanizNl tlIldp lubbll pl(Hlmtlt whielt i~ bn-(tldo on the prill o
ciples dehtilcd tlllLe follows Duplltate nt-gm sllmph of the finely cliyiliNl IlInttlitiup wlirllll out [~ei-()l (all hl lIf((tinmiddotjv INd to lt1iyidl till alllpl) TIll kltolll-olubll portion of till )111(11( tlrc di-olved a- indh-Htpd fot thmiddot lllnkill~ of -tlllHlunlluhhll olutiou Oil Pt 1II hut tIl IUlIp Hn lIn l-fplImiddotd 10 lHI-ml rolllllltti( fln-k antil1ltld(lup to Olllll1l The bnlulUp or till JllO(ldllll i- thatutlilllll on paWs -1- 1 IHI Ii 111( 1(111 1- nIP IXPIP--pd nil til IHi or Iw oligiJla w(lullt of I Ill (I11l1p-I1l11Ilt1 1)(0(11(1
Hupitl PlllimiPJojgtiWllllllllh llIltllOd~ fOJ Ihl llPtlmiddotminntion of ImiddotUlJbll tlnd 1(-illo- ill -111111 Illllph of gutlYllll tiUl IIll dl-eli)ed 111() IlltlY d~o Ill nltlI1lld fOl III Iwl Illhlwl- and l~iJlmiddotb(lLiJlg plant TIllt l[Olllhup hns nlo b(l1l ntuptpl fot IIH lltlIll1illtltioll of lllhbpl ill 11lHhrublwl Pl(Jdlld~ HIIl 1111 hI ndaptld JoJ IIll ann lysis of ynt1J(gt( ic lllbbl[- The llllthmb HIP 1gtn(11 fill tIll fol1owill plimiph- III Grinding
tIll PIOPlly driPl t i~lIl 01 Ul tillg tIll pnHhHt to tll l((lllilllllh~lel of filWlH-- til plllllit qIHlIllilnth( lXIIHtioll 01 IIlbhlI 01 1(--IJl- () llsing oXWllutld olnuh (kttoJls IIt(talp and() fllltil for LIbbel and IH(ltIlIlyptIJllIllIoolYlnJld-o flJllh 101 niJlsl with t(lathelr high IlPililig points 111 to n C) l]olle or in mixt tIll thllt Pll mit tlll rnphllxututioll of luhll(l OJ [middot(ill ill ~() to (l mi1lutp It r(latiwly high 1lllIllllltlltP Ill to 1~11 ) l) lllllipitntillu till luhblI OL Imiddot(ill frolll aliquot () f till oltn ion I IlIlllI-i () f Hlltabhmiddot pl(~(i]litallt (willifhmiddotd lthmwl fOl IIlhlHI Hild llitlifild lllr fOJ JP-illl t~) IIlHkillphotollllliilPIIIIiIlof PlllPlltal of liht tLaIlS mittUl(P lIftlI IlIlbll (II Il in PIlipitalioll 11 II WI( Iplllh thnt (limiJlall till PIIOl dill 10 xtralllOlh (0101 (till dptl1minntinll Iph jill 011 tIll dtwlopllIlJIl of H HIli rOI1ll tlllbidity 111 hpl than I (olot rI
jJlIlpOP-ofallnlyi-I ( p(lllil1thb IIllijOI1ll turbidity or 1llt[lIinmiddotd d(ltl of jgtIp(ii(JlI l)~ lIltlkillU tIl plllltollllmiddottri( ntdillU al tandinu tiJlH~ (dlllilll wlli(h IhlllH(lill-- IP 1llutinmiddotly tnhll) t1ll1t an hlsl~1 oil the (oJlItlIlllItion of IIlhlHI Ill I(ill (lIPIipitat((L
TIll -I(p ill till jll()(Plhul HIP 1-- follOylt (1) 1l~UIIL uJ1lplls of thwl UJfJlllHl (II tliddl(l HUt dlipd 11Illtplial an lXIllltel with11 Ill of till nlnll ill t (oU tlllltIPlll[gtPImiddotatlup oil Iath at 11 Cbull fol 11 minutl I) iIP1lIin(middot(lohd til( (XUtllhllll Jltldl lip to It middotml ynlmlll til( (nlifild by (Illlifllgiuu HlId thlPl IlI nliql1ot of tIl (IalioPlllxUlltl nll Uillltlmiddotll(t to l-llll OIlIIlIllril fiuk- (1) For a trial Ilnditlg 0111 III tlll j liJmiddot~t IllHII IIjI to Ohlllll with lilt Pll shy(ilitnnl a 1(11 it 111 (Dod fill llli lIut ( ptotoJIIltlil IPtlllillg-- of pllllntnl or liuht tlUtllIlillal(I oil n (lpel OphotnJlllllI at rase hng-tlt (If 11 llJ Ill Ol It lollllil1lPtImiddott lloyidld with tIll P10]11 I 1110110shy
Ihlolllltt hmiddot Ii1llI Olllhi lIatioll for -1IpItillg UJlproXilll1l tply Wtl P ]Plwth )0 mp are HHlltk TIll Illldillg lliJtaillld fol tIlt 4-milutl tliall(~ll-
bull
bull
bull
RAPID PHOTO~IETRIC DETERIINATIOX OF R(BBER AXD RESINS 37
ing are referred to a table of equhmiddottllut~ previously p1(pa1elt1 on the
bull basis of 4-minute reac1inJ~ for tilE nmge of lot1telltlatiol1- of rubber or resins to bE elHOlll1t(led tmd gidn thtmiddot -tnnlillfr tillIP fill rUbbEt or resins aiter prE(ipitlltiol1 lwfolE photoIllNliI j(tltlill1 un IUade The r(middotnmining dllplllatt aliquot lll then HHllil up te ol1l1Jle and lpoundadillg ale marle ut the -tandillfr tiUlE iudklltll ill rhl tall1lmiddot for the final r(adillg~ -1) 111( milli1lnm or p(tCPlltllt- of lllhbpL (II 1(-in pr(s(nt are rpadholU a prlpan(l table of lquiltlput for tlll photoshymetric readings h1~l(l ill pnell e1-E on pxpPlilmlItal lhln 1111(1 u-ing as stimtlltlds pure luhbll in 1l1bbtl milllYb aIHI guaYllh ll-ill- lxIHlatt~ in resins detNIl1111lttion I
LlTERATlRE CLTED
(1) lUnSbull 1fl36 THE mURMIXTIOS IIF IOTA RE I III OOl THER llT~II
F1 bullrol IlY U(T1l0fll UfSlfi ~rrnrl r flm lt1 KEYS TI Bill Chern 114 44J-l59 illns
t1 ~ICPHHlObullbull T 1J3bull~ lUTHOO roa THE PtRInCAnu Or a(lIUl IRrIlHU It of TIn
PLRIHEU Htllllflt [ i Bill lallllall 111 Rmiddot 711middotj iIlus
I ) RHBERG P B Ul5 A METHIlO Or ~u(ronrll-nl Hi tIII rUIl[1 f71 ii illlI
bull 14 Hoss W flbull and HARDESTY J O
llH IR1ltDII Of HfITilIZfmiddotR DllIJS ltt 1 Yl fll Off gI bern JIIIlI i ~middotmiddotlf IIl
101 SPEltCE D nnd CuoWELr ~I L 1933 DETER~n-ATIOo OF RtBBER Ii nrllllpoundRBfR Iusr 1uI II1 amI
Em~ifl cttIliIa~~ r Ell i 71middot7i l11 (HI WALTER E D
1U44 ISO~nlS OF PRTlltSrr 1trHpoundV bull l UI n W lHHt (Tnmiddot 1ETS FROM GiYI l~iIl lItr Clttrn SII J UI titJ middotn9--C1 ilIu
17 J YOEbullbullr H lO~( roLORIlETRT 771 IPmiddot nl -W Yurk f H Plrwptric hmica
naly-II rimttry lUll XphHHlnmiddot~ y 1 1
11
HI) ~ fPHELolzTRf 57 111bull Lin xw Yk t H lt PhmeHt CblUlmiddot ila AnaiY~l~-(H lithrry and XIhmiddotILpfIY Y wirh enomiddot rrJlllrjr hy H KtlJnJU11 I
t~1I --- and ~ARVER L 1f41 nlua-w ~in L liLhr IS IP ll~ XIW Yrk
bull For-sale by th~ ~a~fr1nt~nf1ent Dt~c~~ogtnts-~ s t1i rArnn~ut Pn~~~ tJffieshy
Washington 5 D C bull Pl lU ~nts
8 TECHNICAL BULLErIN 020 e S DEPT OF AGIUCUUlUlUJ
bull
IHHH middotmiddotmiddot~Ollll of the ~Jl((iHI ~lnsswlI( reshyquilpd 101 [lh)lI and I(sills tllal~sis (lllss rod wilh lInttPIH(] (ml Loll alld tlitulatioll lJlll((I II]) 101 liSP ill bull IIlnlln~ sto1 solutions of IlliJlPI (olII1i lwanshydlltr -AIIlI lYIX ((1I11ishyrllg tulJl wit Ii 011( poillt (0) nIHI flIIpI stie ( J) I fOlllSP ill P[)lIill~ utl (llIdiIli (X( lels witlt shyout di~tlllhill~ the inshysulilhll Ipsidlp
bull
Glns pound1111])(1 ) jlllll in ((iamptl for 1( ill tltlm~rprljlJg- pighpll fllJlplpS HIIl1
bull (lnrin(d IXIIat to -llil ohllnlllI f1aI~
i(p-mollllt gingt hntl will llntit OJ 11I(lal J(IP (n] fOI toling- gIollIH plallt samp(
Halmiddotk for hllldhlg ill-llll middotPIlIlilnp nlHs IIIH ~i-1I11 YOlIll1pllit flll (Jig- 31 Alltolllnti 10(1-1111 ~middotI(lX IlIllPUp of IhI fq)p llsltd fOl Iitis with intpl(middothallg(middot
nh1t H(JlIlHI joint 101 rl1phl lPfIPIIIlg (lj 1lIhhpl fllld 1(ill lll((jpiltlllls
bull
FllilHE Had Iqllind fool IIJI(lill I 11 (111111111laquo llllmiddot alHl (I) limJ VfIlIlllllJi( tlak~
bull TIll itl1jHlIlWI of n Illb tlpl of d(Hdill(~~ III [gtJ(Jtnllllllil lllll~
i dblmiddotwmiddotpt hy Y (J( I _ j J i) t Illt riflllmiddot t tth~ n n Ii 11 111 h111 I t1loOIlldy witl nap lllltlIHI 1111 1l1id bpll tlll- HII lill(ll with (jtt11lill olutioll Hlld ltll If fla k It It [lllijljtnlld 111bhll nl
11ill lIll til ~tlllld all 111th Ill lillI Illmiddotforl 111l In 1(11 it j~ luhmiddotjlIll] 10 1111 0111 ilH (111(11 11[ Jpli~ Ii tllp wall TIll
10 TECHNICAL BULLETIN 920 U S DEPT OF AGRICULlURE
25- and 100-m1 volumetric flasks arc rinsed two or thrce times with tap water and then with cleaning solution al1tl watel as is customtny In all cases the rinsed glassware is dried in an inv(ltell position at 100111 temperattlre 01 upright in a drying oven The flasks used IoJ extracshytion of rubber Iron1 kok-sagh)z (Talllrl(((IM1 kO-8aghyz Rodin) are finally rinsed wHh the solvent to be used and are nllmnd to lt1Inin and dry under a ventilated hood Cuwttes 01 absOlption test tubes nre handled and cleaned aH directed by the manufacturC)s of the llhotoshymetric instruments used
RUBBER (CAOUTCHOUC) CALIBRATION CURVES
GENERAL CONSIDEHATIONS
The lubbeL hyclroc~rbon stau(ild is pllpa 1((1 by extracting the rubber from guayule bssue ac(ordll1g to tilt SPCI1((-Caldw(llmethocl (5) 01 by the Holll1lH-HaasiH modification of this method (p 2) The air-dry extraeted ltlbber is dried furtlllr in It vacuum OYCl1 with 30 inches of yaCH1Il11 at 63 0 C for 4 hOlIlH Till rubhlI sbindanl is preshyserved h1 It clos(cl contaim1 sto1(d in It r(fligellltol BCfole th( samples nrc weighe(l out the unopened cOIlbdn(l with the rubber i~ brought again to room tllllpelutnre
Two stock solutions each in triplicate from separately extractml standard rubber satnples nre prepared-the first sct of (-111(( containshying 01 percent 01 1 mg of luhbC1 ])(1 lniHilit(l and the other 02 pershycent 012 mg of rubber pel miJlilit(l TIl( (I(~il(d w(ight of rubb(L contiiinec1 in It known VOlIl11e of th(~ solycntis withdrawn Irom Il
burette or pipetted and made up to 25 m1 the standard volume used throughout the procedu]e
The rubbcr samples (01 and 02 gn1) for the stock solutions are weiOhecl out to an aCClllal) of o~ mg on nn analyti(~al balance The rubber is best mnnipulated by mNlI1S of t1l( stJai~ht hlunt-edged top of It cork knife With a little prnctie( OIl( (an leltlily sepnrate t)w desired portions by pLeSSIl1C from aboye Further subdivision Is mndt on a stout PVllX at(h glnssnt lla~t 2 mill in thlkne~s By pressun f10111 above and sheuling aetlOl1 Ye1~ small pnrbcllH can be separntetl so that the requit((1 11l110unts (un 1)( w(igh((l Ollt accurately The rubber sample is then divided into sl11a11 piC(es on the special watch glass by meanH 01 II coll Imife
One mil1ilit(gtl of lt1i isobutyl ketone 13 js placed in It special 30-m1 trituration beaker (fig ~B) and the fine1y diyilt1ec1lubber sample (01 or 02 gll1) is udd(d and heated on a hot plate under n ventilated hood to Il tempelature jllst under th( boilin~ point of the olvent A special glass rod il used t () t rit II ate the sumple (fig 2 11)
When the rubl)(r hll d issohed so as to makl a hOll1og(J1lOUS geUike 111I1SS hot methyl isohutyl ketone or an oI the other luhb(L solvents recommended (t aIJI( 1) is add(d and niicd with the rubber soltItion
31 Diisoblltyl ketoul WIlS not aailab1p (Juring ValtimC l1Cthyl isolJutylletonC 1II1ly be substitnClt1 11111 it is not a~ Cf1kiCni In Illis olllntion If the IllttC1 is used It is b(SI to pl Ilw fimlr diillPll Iubhpl palll(s slan( oPIuight in Ih( solvCnt lind 10 (OPl til (onlalll1 to IllinilllizC elIpornt(111 of sohPIII bpfolp wa( Is nppliecl to completp nlutioll
bull
bull
bull
bull
bull
bull
RAPID PHOTOMElRIC DElERMINAlIOX OF RUBBER AND RESINS 11
The mixture is tllll1sterled to It 100-ml yolumetlic flask with sevtlul washings of hot solvent cooled to n s(uHluld telllpelatUle and madtmiddot up to volume with the saIne solwlli SlwtiaJ IHl(uutioll mllst be takell in transferring t)( lubbCl solutioll to till YolulIHtrie flask so thnt llO rubber is lost It is cOllytllielit to illSllt It j-ill(h funnel in the ne(k of th(~ voiumptic flask to pOll tll( lubb(ll solut ion ill OIl( OLWlHtion into the tube of tht IUlll1ll with Ihl aid of tIl( glllss Iod nlld 10 follow illlshyl1eilintely with S(gtllnl ~Ynshings of hot S() I(111 whkh lIl lilst pouled 1nto tIll btll PI 1I(ld dIIleUy OW) till 1unn1 aId IhpII t1I1uugh Ill( funnel
H time hi not all objllt it is uls() flasible 10 p1alt Ihp linely diided particles of Iubblt ill tl( flask toJ1tuining Ihl sohPIlI 11(1 allo it 10 stand until til( 1lIbbpI is dissolYld TIl( llIblJll ioluliol)s alp slolpd in Ihe tightly s(ojlP(1(d OIUllwt lit f1nks in a ((lol dark placl Thel they willltIIlUlIl (OlUilallt ill Idut 101 an indlfinit( JlPIiod
Two ellliblHliol1 (IlP~ flIP IIltl(l(-OIl( 101 o~ gill of tisHlIP (ollin illshyhw 0] to 10 PII((Il of rubb(I ((1lt)middot1 to U mg of IlIbb(Iill tt ~)-1Il1 yo1ullll) and th(middot otlHl for ()~ gil) of tisslIp (ollaining 10 10 ~l() peLshycent of lublJPl (O to 10 Illg of lulllJpI ill a ~)-))Jl YOIlII1IP)
(Hns HlJ 111 TO 1 II~IWEX( (II BIIII1EH
III oldl) to ll(llllP (ITOI (0 II Iltinil1lIl1l a lIitahl( lllillobllllltp is lIs((lo Jl((lpn (P IhI ~lt of stal1da Id solut iOlls 0 f a Ii ng (OJllllllllll ious ill til(gt (III)(r( Ol 10 1 gt(I((lIt of LubbI In (11( PI(sPIII WOlk th( 1111shypIoypd HlhlHIg mic)obm(ltp Il bullJ) whkh lIi(IlJalpl dlli(I~ 10 0001 1111 was Toulld sntisiadOlY F(OIll n lll-pltIllllt -talHlulIlllbwl solushytion in HSlIitnbh solnnl lt[lIiIlIUJl1iiat( aliqll()l~or n) Ol o~ n and ()t 1111 al(lllla~UIpd (Jilt ut n stalldUld ~Olllli(lll tlIlIJl(1atulp (~) C ill wlitllmiddots labolulol) I IlIIHIl-of II lllillOillIl(tlt illio ~l-lld yohulI(lie f1nks ploid(d it h gla -(OPIllIS gllollgh of 11ll lubhpl sol Pili i~ thllI addltl to (tl(lt flask to IlIak(1 l 1111 Ill1I IUI(middotc (0 t hl all)ollllt of lllbOPI solutioll ]ll(yiously nd(lpdbullflll DI ntl 01 JlImiddototlmiddottli lolloid solu tillil Iras h(PIl Hddld lIP (bhpl is JlI((i pi III tpd IIlld SP(middot(t )opl)()tolllshyd(gt( 01 (jIOlilllltp) IPallil) an IllHdp 1I((OIdillg to 11ll JlI()(pduJ( Oil shylitwd Oil pagp 1middot1 Th( 1(ldillg~ 101 palmiddotll (OI1((III)Hlioll alp 1I(Iaglt1 anel plotttd Hgaillsl t( ntilligllIlll of 11))1 hI n ~)-1ll1 (jIIlIlH 0) [gt(lClntagl of nlbblI (nltuln(pt 011 tw bnis of tl2-glll lilsul Slllllp1(gts and aliqilOt olulllt IH(IOI 101 (itl ]1I(J((dlll( out lilll(1 Oil pagl 1middot1 This PI()((lhll( i ((l(alld t win ill (a(1 (11( II slandald llIbbllsolushytion was PI(gtllllpd IIOIlI slpa latll XllH(1 ld 1 a utln)(l lllbblI 1 III pips TlwcOlllpl(tpdtlla alp pol(l (1) (loldilla pap(laslrowl1 ill figulp I
Tbl )llO(p(II I ill lllilking a (Uln rOl I to ~ jiI((lIt of JlIlJh(1 i~ simi1t1I to (hat rOl 1Ill l1IlP ImI1 to 1 JllI(PIII (x((pl ill a f(middot dptnils The quinlu]lli(Htl aliqllols a 1( sput(d Ht (lI 12 a j 0 (78 n alld 10 mg ])(gt1 ~i-1Il1 Yolunl III sNuIing thp 01 Illg pll 2)-Jll1 YUlll))lt til( (gtIO(ltlIII( outlillPcl ill IIIl PIp(tding pnltlgllIph is followpd In the rllngl 1 toj Illg )IN ~)-1I11 OtIIl1I Ilw (lsi 1(lt1 (oJ)(tlllltlliollS of lubbpI alP s(gt(ul(gt(l h IlIPHsuljng alhplOi- with Xnlional BIII(atl of Stnndlld~ tltllsf(I pip(Ws flOIl) tltl OI-PlIl(1l1 lII))ll sol III ion
12 TECHNICAL BULLETIN 920 U S DEP1 OIr AGRICULTUHE
RUBBER IN 25-ML VOLUME(MGl
100 1~__middotOT5___ITO___15__2~O=--_bull 2r5_---= bull 3rO__~-_40 bull99
98 shy(I) CI Z
~ 97 ItJ II
~ 96a f-IIJ
e95 o l
94
93
92 ~__~__~__~____L-__~__-L__~L-__~__-L__~
o 1 2 3 4 5 6 7 8 9 10 RUBBER (PERCENT) bull
FIGURE 4-Cnllbrntioll curve for rubber in 02 gill of gt1n~ule tissue containing 01 to 10 p(rcpnt 0 lllbhlI (nlnllillg~ (Ill 1111 J~pl~ll llhooplf(middotttmiddotlc colorimeter with 720middotmu filter und amiddotml uperture the 01 divisions required in actual pracmiddot tice for photometric IclHlings arc olllittltd)
Similarly hl the range 5 to JO mg pel 25-ml Yolume the desired conshycentrations of rnbber urc measured from the O2-pllmiddotcellt solution The complete data lire plotted on semilogtllmiddotithmic pttpel as shown in figure 5 A
STANDARDlZATJON AGAINSL G1IA111 ETlIIU 11 ETHO()
1he alternate ploee(lule of stt121l1ald izing th~ IneHell~ method ngninst the Spellcc-Cald well method (II) altholl~h flaSI hIe 18 not adVIsable because of the extra work J(quiled ancl the introduction of the expershyimental error of the benzene extraction method
HESINS CALlBllATION CUIlVES
The procedure for constructing cal])lation eUlves for resins ttIlulysis is similar to thtni outlinlltl for lubb(l lxcept that resins exndate of gunyule is lIsed as the resins stundard The resinolls exudate disshysolves very readily in the resins solvents listed in table 1 It may be prepared in two ways for use as a stnndard-the clean exudate as bull gathcrcd from the plants is dried for 6110mB nt 65deg C nt a 30-inch ltcuum or the oXllllate is dissolved ill acetone and filtered In drying
bull
bull
bull
RAPID PHOfOMElRIC DJllImlMINAlION OF RUB BEn AND HESINS 13
RUBBER IN 25-MLVOLUME(MG) 2 3 4 5 6 7 8 9 10
r~
eo en ()
90
f--70z Q ~ 60ltl LIJ a ~ a LIJ 40 E 0
0 50
~ 0 ~ I 30 0 ~
A 20 I I
o 25 50 75 100 125 150 175 200 225 250 RU88ER(PERCENT)
RESINS IN 25-MLVOLLIME (MG) 2 3 4 5 6 7 8 9 10
1--90
80
en () 70
I z Q 60ltl LIJ a
50 0
a ~ LIJ 40 E 0 0 ~ I 30 0
B ~I20 o 25 50 75 100 125 150 175 200 225 250
RESINS (PERCENT)
lJIGunE u-Cnlibrutioll cUve for (il) rubhcr in 02 gill of gllnn11c tisme conshytainingl to 2G perc(lt of 11IUU(Il I1na (1]) rpSillS in 02 gill of glI1~l1ll~ tissue (ontnining l to 20 nelecnt oC l(sin8 (U(ndings Oil 1111 E(lI~1I llhotollectlit colorlmeter with 720-mtL filtcr and O-ntJ aperture the lO divisions llquired In uctnul prllctlce for pitotoulPtlie PllllillgS tlre omitted)
in vncuo arelntivply HllHlll qUllntity of (xutlnte is plllcel] in a lalge dish since the mass rOHmS nt the beginning of the drying process Pracshytically ull of the ne(tone is evnpollltpd olf oyer a steam Ol WItter bath and the residue is dli((l pnlYllized in It mortnr and preserved by
14 lECHNLCAL BULLErrN H20 U S DEPl OF AGRICULTURE
drying as indicated for fresh exudate In all ClSeS the products are stored in airtight containers in a dark coul place
The usualllnge of resins from gunyule tissue is about 2 to S percent on a dry-weight basis For work with this plaut therefore on1~ one curve is needed A typiCallesins ealibrntion CUlTe is shown in figure 5B
PnocEDuuE J~OH RUBBER ANALYSIS
Duplicate lXiLllCtiOllS arc made for each tissue analyzed and duplishycate photometric readings are made for each cxtmctioll the final value therefore reportcdreprescnt- nn avcragc based on the four phoshytometric readings
Thoroughly mixed O2-gm samples of the finely ground tissue are weighcd for analysis on the basis of l11oistUlc-frec tissllc The samples arc weighed to an accuracy of 02 mg Oil an analytical balance The method of deriying factors for making eOllections for moisture in samples has been thtailed on page
The weighed samples arc trallsien(c1 to the 2-m1 volumetlic flasks with the aid of l-inch glass funnels and 20 m1 of methyl isobutyl ketone is added to each flask The contents in the Hasks are heated m a constant-temperature oil bath at 115 0 C for 30 minutes uncleI a yentilated hood rhe flasks are removed and any adhering oil on the outside is wiped off with Kleenex 01 H similal cellulose tissue the C011shytents of the flasks am cooled to a standard tempellltule (25 0 in the writers laboratory) in a constant-tempelutllre ater bath provided with a motor stirrer if available and made up to volume with the solvent After the contents are mixed the flasks are allowed to stand for a few minutes until most of the insoluble residue settlcs to the botshytom The extracts are then carefully poured into JO-m1 heavy-duty centrifuge ulJls so as to include as little as possible of the settled insolushyble residue The centrifuge tubes are stoppered with cork stoppers and the liquid is clalifiecl by centrifuging for 10 minutes at 2000 revoshylutions pCI minute The clarified lIquid is poured into 25-m1 volushyl1Ietric flasks plOicled with ground stoppers It i impoJtant to pour off the clalificd (dlart in lWIt a lUlllie that the ill8ol11ble cNi(hwis not Sti1((Z1tp A 1-in(h funllel is plncCd in the neck of the volumetric flask A filter stick (fig 2 D) is inserted in the centrifuge tube through he liquid so that tlH enlnlged palt of the gtiek seals off the insoluble residue and a small portion of the exmet in the cone point 1Vith the index finger the stem of the filtel stick is thell held against the side of the tube towllnl the analyst who holds the tube with the thulllb rmtl t11illt1 fingCl The txtlHct is thell poured off easily into the yohunetlic flask without distnrbing the insoluble residne The COllshytents of the Hasks are then ))ollght to the standard tel11pelatme in the constant-tempentl111e wnter hath
The reagent blank us(d wit h the spectropllOtoll1lter 01 (olorimeter ig prepared as follogtvs ) 1111 of methyl isobutyl ketone 01 other solvent used is pipetted into It 25-m1 yolumetric fiask and 01 ml of protective colloid solution for rubber is added the mixtule is made IIp to olume with acidified Oil-pelcent ethnnol and mixed again the rcquired vo]shylime of the mixture is poured into a cuy(tte or an absorption test tube
From each plir of tissue extractions to 5-1lll aliquots 01 the clarishyfied extlact at the stnndanl tempCraLule ale pipcUed into 2ii-m1 volushy
bull
bull
bull
bull
bull
bull
RAPID P1IOTOMElRIC DETERMINATION Ol~ RUBBEH AND RESINS 15
metric flasks and 01 m1 of protective colloid solution for rubber is added to each One additional5-mL aliquot from each pair of extracshytions is similarly prepared to serve as a key to the standing times for the final readings as indicated in table 2 These additional aliquots are first made up to volume with the precipitant acidified Do-percent ethanol mixed by carefully inverting the flask three or four times] and allowed to stand for 4-minute periods before the reading is made on the colorimeter Vith these preliminary rendings a~ a basis the standing times for final readings are taken from table 2 For example if the colorimeter reading in rubber analysis at 4 minutes is 655 then the standing time is 15 minutes
The two rell1Lining duplicate aliquots for eath extraction are then made up to volume with acidified D5-percent ethanol mixed by careshyfuIly inverting the flask three or four times nnd allowed to stand for the required number of minutes as established by the preliminary 4-minute trial readings (table 2) before the final colorimeter readings are made on the contents of the flasks
TADLE 2-St(llllliIlU time for variolls (OllccntratioIlS Of rubbcr or rcsins aftcl iJleaipitation bcforc colorimetric readings mc macle
[5middotml aliquots of rubber in methyl isobutyl ketone or of rcsill~ in ncetonylncetonemiddotcellosol e 3middoti both made up to a 25middotml volume with pr~cipitantj readings on lvolyn photoGlectric colorimeter with i20middotml (690to iiOmiddotD11) filter and Umiddotml aperture]
RUDDER I
Range of colorimeter Approxima(e S~nuling i Rnnge of colorimeter Approximn(e Standingtrial readings after 4middot range in conmiddot tJIIIG for trini r(adings nfter 4 range in con tifillnlOalcor minute stunding time tcnt In tiSSU(l Unnl I t I t (rending IIlIDU C stum Illg lOW _ tent III Issue reading
Percent Villlits II Perfe~lt Jfinul 955-999 bullbullbull bullbullbullbull 09-01 00 01-03S bullbull ~ _bullbullbullbull_ Jl-O9 10 743-954 bullbullbull ~ bullbullbullbull __ _ 43-10 30 1420-550 bull ~ ~ 137-94 5 6_3_9-_74_2__bullbull_ bullbull bullbullbullbullbullbullbull_-_---- 6__8-_4_4---___ bull ~ ~ bullbull ____ MQrcthan 13ibullbull_-~_ _ ____ 15_~elow t~ 2
RESINS -----------------------------~--------
957-999bullbullbullbull ~ 139-01 60 11419-amp11bullbullbull _bullbullbullbullbull ~~ 13~5-939 10729-956bullbullbullbullbull_ Ii 25-1 middotJO 30 ~gtl2-40(L bullbullbullbullbullbullbullbullbullbullbullbullbull _ 2025-1320 5 595-728~~~ bullbullbullbull 8 as-G 20 20 IBelow 292 bullbullbullbullbullbullbullbull- More thun542-591 _bull ~ bullbullbull_bullbull_bullbullbull 038-039 15 2025 3
I Precipitated with O5middotplrccnt HSO in 05middotpercent ethanol When the npproxilllull concentrntion of rubber or rcsins in solution is not known trinl colorimeter rend
ings atmiddotJ minutes s(nnding till nrc mndelS n guide to the required finnl standing time indicated in the last column III prncticc UII cxtrn nliquot is prcpnred for precipitation and thIs is discarded after the trial reading is mnde
3 lrccipitnicd with OmiddotpcrccntlhSO ill HO
PnOCEDunE I-On UESIliS ANALYSIS
The procedure fol resins unulysis is the same as that indicitted for lubber analysis eomiddot(I]lt that f he -olyent js acetonylacetone-cellosolve ~)-7 tht precipitant js O5-perctnt H~SOI in H 2 0 and 01 1111 of the protective colloid solution for nsins is added to each 25-m1 flask conshytaining the aljquot of the extract before the precipitant is added
PnOlmmlHlC INSlHu~mNTs UECoIUlENDED AND CALCl]IAlION
OF UESurlS
Photometric readings of percentage of light transmittance (T) ale made on the Coltnum double monochromator spectrophotometer at
16 lECHNICAL BULLElIN 920) U S DEPT OF AGHICULlUHE
750-111 wave length or renclings n1( mnde on a colorimeter pLoic1eri with the monochromatic filter eOIl)Il1l1tioJl for sllecting the npploxishymate wfLYe ]cngth at 750 1Il~ For routine deterlllinations the Evelyn photoelectric colorinwt(r ployided with aTW-lllJ filteL is IC(0l1111HIHtll
The liquid in hich the preeipitnted lubber uld rcins are susshypended is pOll(d very cHrdully down the ill~idl of th( clette o absorption tube to lLYoilllllC fOLll1ntioll of ail bllbblls Aft( LUbbet find resins preeipitation wlwn the EnLynpho(otkcllie (olo1imetll is used the readings are nmde nft(L thl standing tillll- hOWll in table~ It has been foulld (OIlllliellt to 11lPtipilatl tublwr 01 llsiIlS from the aliquo(s at ~-millute illtlLvals This allows stlilieipnt tillle to check the eOlolimet(r and to makc 111( lNHlings Vlwll a ehangp is IlltHk fLom onc rending 10 the l1lxt it is advisablp 10 llle the clIvctte 01 absorption tube nt lpast twkp with slllall p(Iltion- of the llllltiol to be leitd
After the colorimd(L lluding lta e becll Iltndp till IlIl II igllIlllS of lubbel or resins or thc lpL(el1hlges pnslnt in Ihe aliqllot are r(u1 from cal ibmti(Hl (urVlS (fig~ 4 and raquo or from plepn Led tables of eqllivallBts baecl ill each (liSP on (x[lerimPlltnl data The results are expressed as percentages of dry weight (S hours drying nt 100deg 0) of the original tissue The errol lltle to lCflyjng the insoluble residtH in tbe voltlllletLie pxtLHclioll flflsk wlwn the pxtrnetis being mnde up to YOlllmC is V(ly slight sinlte only (U gm of tissue is used FOLroutine allalyscs lhis ery slight eLlor mny be dislpgnltec1
EXPERIMENTAL RESULTS
The experilllCnlal reslllts Oil hi(lthp method- of tU)lPI and l(sins analysis a le based ttl( d icussld blicfly hlrehl
PHEPMINrlON OF SAlULES
No difliclllty was expPtitI1(ed in pltparing slmplls of llllrscly-glOrt guayule plants 1pss thnn ~ YPH1S old 101 rllbbpl alld IPSills analysis In the cnl of Odll filld-gl()n gllayull plants PIIOtS hopel mtty be introdmp(l by the custOlllalY Jlwrhod 01 pICpalillg Ihp sampl(s 101
HlutlYHis as is lwipfly i n( ita ttd ill th is s((tion Smh enOlS do llot nffCct the ])lCcisioll O[ t1H llwt hotls for LllbbtL n nd Il~in~ nnn I sis i nee till) are due solely to tIl( tbsup--ampling (llo(pdule in thi (a~e of oldeL field-grown plall TIll 1lllt1lOcl of salllplill7 fipld-gl()l1 plants JllOLC than ~ Y(HrS old thenfort Ieqlliles iurtlHl jnttigntioll
lgtAHnOILr~G FOR HEllOVAL OF UUVLgtS
Parboiling which (onisls in boiling gllltyule plants in water [OJ
8 to 1~ ~ninll(s ~s col1llllonl) uSNl a~ n llHans of Itlli rCnl()y~l prior to drymg nnd gllnllng It I~ tHI([())P ll(e~Sllr to ltItLeLnunc all possiblt~ eflct oi tlti PLOtPlllll( )ll (Il( final results Exp(liments have sh(nm that (helt i- fl Flight loss ill til tmiddotjght of lOO(S and 4(ll1S In I typi(ul lXpelillltll hlu1llHs of ~- ii) -1-ytII-old gllllll( pllllb were Italnd at randolll Olll ( of talns wa- paLllOil((1 and the le~es (1( haIHI-pi(kpd [lom till o( hpJ Ht Both pis (1( dlipd for 48 hOttlS at (i) C in a llI((lwlli(al (011((( ion Oyell Th( lpsult are SUI11111I11izNI itS follows
bull
bull
bull
bull
bull
bull
RAPID PHOTOMETRIC DETERMI~ATIO~ OF IfCBBER A~D HESI~S 17
Dry ucilht lust ill lariOilillf
Plaut (pcrcrllO 1 1 -I2 ___________________ _
213 _____bull _____ bull __ _______ ___ ____________ 12 2(
pound(111_ ______________ 1 R
4_______________ _______________ __ _____
A __ bull __ -_
The efred of parboiling on till final lllalp i SUllllllatmiddoti7(middotd ill figmc G Rubb(1 lecoYelY w(t about 1 percent higher for parigtoillltl plants and lEsills re(ovelY somewhat o-er 1 i)(lr(lllt 10Wlr The (Ii tference in lublH-l r((o-elY cannot be ae(01111tltlt1 fot by loss in dry weight _ due is to be found in a study of thE grinding lwhadol of a parboiled and an unpnrboilEcl shrub The grinding of the patboiled shlub in the hnml111 mill is much fadlitated and ns a rule for tissue with a rubber contCnt below 10 peteent llO aggregates of rubber deelop in the 1Il11ehinr during the (Jpelatioll Yitll the unpnrboilNl shrub some dillictdty may 1)( (lxppliellrl(l Sill(( sOllle of till sti(ky ltxlldutl Oil the plant may scI( u nlldei for the fmllHltioll of lublH1 ngglPgates Til is apparently explnins the npparlllt los in ruhbpl frol1l the llnpariJoiled hrllb as eompnlelt1 with thl palboilld (fig (i) TI1(loss in r(sins
II
RUBBER
10 f-
Ishyz LIJ 0 0 LIJ 0
9 --RUBBER -shy-------shy
-- RES INS -shy---shy-----_
IJ) 8 I--Z IJ)
LIJ 0
0 7 f- RES I NS -0 -shy0 LIJ III III J 6 f shy0
LEAVES REMOVED BY PAFltBOILING
5 f shy -shy - BY HAND PICKING
4 I I I 35 30 25 20
SCREENS (SIZE OF OPENINGS IN MM)
FIGlRE Ii EtIe(t IIf pnlticlp sizE Oil lEcorPQ- of rubber lind (iiil1s when lEgttiye wEre remond hr Pl1liloiling lind h~ hand pi(king ((Dlltrol) plllllt1lt groUlld in t hammer mill
6114038-46-3
18 TECHNICAL BULLETIN 920 U S DEPT OF AGRICULTURE
recowry from pUboil(d shrub may be due to the loss of the resinous exnc1ate during parboiling This exudate forms ns It SClim on top of tlw )iquol in the tank
On the basis of t1wse results the recommendation is made not to yaly the nwthoC of leaf lemoYal in any 011( lNi(lu(h project Then fltirly compalabh IcmLts should he obUiined
70 ~------------------------------------------~ LEAVES REMOVED
BY PAR80lLING ____ BY HAND PICKING
60
-I-Z 1amp1 0 50 a 1amp1 a
en 1amp1 gt1amp1
40en gt-CD Q 1amp1 Z
I shy 1amp1 30 a l shyx C)
1amp1 ~ J 20 I shy 0 I shy
10
O+--L__L-~__L-~~--~~~~~ o 10 20 40 60 80 100
NATIONAL BUREAU OF STANDARDS SIEVES (MESH)
FlGntE T-lJiMlil)utiun of l1Ultkh si~(s of gnll~II( tiSSU( JrIOllll(l in a Ball amp 1ew(1 mill to pass six dllIerNlt S(I(euroII 1(IlYes Iemoved from plants by palmiddot boiling 11(1 hand picking ((olltloll dpfo1iatld plants dried to 1I lUoistufl l0I1t~nt (If 01 to o) 1)(ICl1It ground tiSSlli IbalH1 1() minutes ill II ~i$hel
bull
bull
bull Kahn shuk(f
RAPID PROTOMETRIC DETER~UXATIOX OF RrBBER AXD RESIX-i 19
GHl~DIgtiG
bull Th~ entire pant 01 plant l)iHt a~(gt fl r(ll it pllllIIirU1ry lSillg fur J hours ntGi~ C prIOr tD t 1( plChmll1atmiddot rLlmhll III a II lItmiddot or n Ball amp Jewell mill ~n llltllysis of paldch lzP- nftl~l (oar-( IIindill shows that tlwy ar( about tIlt llllH fOl parbojlP(t awl IJllllluhoileu hrubs I fir 7)
The coalilly gloUllll ample i-- thPll Ildlll forI toUtmiddot at ni C afnr which it ha lllilobtllL(gt output of ~ llllut lII hmiddot- dptPlIIlilwltl by drying submlllpil- at 1110 fot hOtll- TIll 1 IIIIll i lltllt lmiddot0l111d hi a IluninHl mill TIll mo(lel uP(t in thi IIIk i 1I Hu IIIOilll mill as IllUllifill bv Hoss nnt Hartlet ( 1 -[1lt111- with n1ll1l1 pldushyrations ittI lilnbhell b rill HanlIolll V0ll11nHiol1 ElIillllmiddotrill (0 The size lutllihl11 iUlJnole So I ( 111m t ~ II t HUIII Xl) ~ I L~ 111m nnd So 4 lillllU1 11 ttllilhmiddotj 0 r tllP Imiddotlult~ p(lln-It willI t11(e Sll((IIiZtS with )arl)Oiltll awl uil)Jtllboiltd hrlll b lOwl1 in fif1l1fmiddot-- This hows t tnt 1middottttIl ~(I 1 llllll (Up jlllilnl IHlt that
r------~-------r--- ~ --r IHAMMER-MILL SCREEN
O~ NO1
NO2 ---shy U NO 3 ---II
I
bull lL
z
r ------ l 30 ~ gt III
i I Imiddot
i ~ I
I 1 I I
~ 20 I - 1 iii 1[ r 10 ~ ~ ~ I _ ~ I r A bullbull
o bull L-~__~__~~__- ~~ 20 40 60 80 100 40 60 80 100 200
NATIONAL BUREAU OF STANDARDS SIEVES (MESH 1
Yutln I i-tlillltiuli Hf pur id lZt f ~naY1l1 t middotnt r1 lI1 i ~ a hatlltlllI 1IIi11 to 1111 Lx IHtllllH middotIn Lt-anmiddot tIlllunl loy la1 litkh~ omrl t 1) tHul parbuih~ -t B ~ thmiddotfuliufptl ]~lahr thpt tu tt fit t 1 It+gtr-tt1 Jnui~tHn eunttlIt _~rnlitl tl~UP ltakmiddot~~ 10 UddU it~ 1 rtmiddot4~pt~middotK1~r ttakt-middot
bull So 1 gingt- 11 tt-liuin-Iy ltr~pl [lPlItl1tat of iilll 11animiddotImiddot- Eqltrimiddot tIlllll hnnmiddot llOWIl dutr fll llltldllllUU xtlutioH 11pound lnhbll lIl lP-ill frolll IolUlIl ~tlaYlllt tl-IlP by dlt IJwtmiddotlUlmiddot lItlilwd oil Ill 14 - 01
i-mllt 11111- -lwltld hi INd I li~ Ii I TIll lllhtIlttj of Itiu~ So 1 (lltll j thnt 11middotmiddot01middot lttwmiddot to amplil tltt Iollllli tilt art lpdnn ib
IntIIll ll~ i po--ihJI with tI lLllit Ilfltl[lll1t It honld l Plllplw izmiddotl rImt ilt tht h of -allllhmiddot with l lllblPl
~ontlnt of ill PPltllt til lIilll it i tlllt pll--ihl 10 11-middot t(1i Xli L
20 TECHNICAL BULLETIN 920 U S DEPT OF AGRICULlURE
Even with screcn No 2 difficult due to rnbbel tlcrltreCtlltiollS may be ob tl
encountered In thes~ caHeH it iH lWit to parboil the shlub fOL leaf lemonll and finally to dry to about 1 to ~ P(l((llt of tnoiibl1(l pound01 b(~t results jn ~rindillp in tlH hanmHl mill
It iH aclvlsable to provic1l thc hammer mill with a ground wire Hillel the presence of static electric (harges 011 tll(middot partkhH will ealls( Home of these to atlhelc to the inside of tllP (olltailWr OJ lila eallsc OI1l( of till pULticl( to form ngg1(llatls EIIolin lalllpling fl01l1 fhis SOI1I(I mlly be (onsi(h1llbl(middot
A1I10l1g the Holnllts with high boiling point that lIlay Ill IlHld in rubber anal)Hs I1IP Illllhyl n-alllyl ketolle methyl ioblltvl kptOIH diisobutyl (tOIH blltyl tHptate llethyl amyl 1Ittail (middotthyl(middotlllmiddot gly(ol diethvl (middotther and n-bntyl (middotthel (labl( 1) TIHse al( also I(sin 01shy
middotent but th( 1(~illS n1( held ill olution by the rll1)bpl pl(l(ipitant tthanol wll(1 lllbb(r is 1)J(lipitatNI (S(ll tabl(s alldmiddotl) On tIle basishyof the lxpHilllPlltH tll( btsf nil-round lolPlli -rol lS in 111( PIlHPllt method is lt1iisobutyl kPtonc wld(h was not IIltlllllfaltllllmiddotd ltIlling Vodd Yflr n A suitable Sl1lgtstit ute iH llHthyl jolllltyL htolt whi(h is l(porhd as llolltoxit UJ)
Clllos()IY(~ (ethykn( glYlol monopthyl (tIH1) blltyl earlgtitol (di(thyl(ll( gly(ol llIollobutyl (ti1(r)~ and acttonylacetOll( may be used as resins sohrCllts (table ] )
In the earlipr work with (sills analysis cpllosoly( alolle was selcmiddotet(d as a suitable solycnt Aitholllh (ell()~oh( alone is pxc(lllnt its rplllshytiwly gwatlL iscosity 1(I(b to bubbl( formation nft(I (SillS pr((ipi tatioll Thi- increased thp (xperimentnl (LTOI OIl of tltp othll I(sins solpnts tI((tollyla((tolH has the proppry of glpatly lNlulingshydH(OSity 11(11 altld(( 10 othr liquids This sohpnt tlHIeforl wa addp( to ((Uosoh( in slIflici(lJlt tlllIonnl to OPI(0111e the dinieulty On the basis (li~ex)le1inwllts ~ purts oi~ a(donyla((tOlll to I puts of (elloshysoh-f (bolll by olume) as Splldcmiddot(l Thp 01 hel Hoh(nl listed hutyl clLlbitol at l(llst the t((hnieal-g1lld( ploduct uSNl is appal(ntly not as good as eithe of t1w ot1(r two () a (ombinatioll of tlWSt
The SOlVllIts JOI liSt in tumlyzing artifkial lubbel$ hy tlw pr(senf method appllLently (lcllIHl on th(middot kind of llI))(I lIp-ityl (Jxidt is suitable Ol BUlla fi and hutyllthlI for butyllllbbl Tlwse reagents IlLe technical g1lld( Calboll amp CtllUil1t Ch(lllilai (OIP This Hllbjp(( hilS not bepn (XtpllHl(ly illwtigated by till WIit(I
PIIECIIIIJ-
All tlst fOl Ih( adlqlJalY or till IHllipitullb ll(Ollllllentillllll11Sl bl baset] on the plctisioll of tllP final I(snlts oiJtairwd with the methods The )redpittlllts s(1e((( n HpJ (xtcllsi( (xp(IimPlltatioll all HatiH~ factor (Hee fig Hi 111lt1 tabItmiddot (jH) Ext(IIin tllts llllTild Ollt hanmiddot shown that H Hatil-gtflltlOIy [gtIpeipitallt 101 1lIbblI is (li-p(IT(middotnt HzHO (c p reagent nil POll sp gl U-lmiddotJ) ill li-P(l(Put (tinmol by vohmlP liol (tllayul( Ipl-gtinl 1l)-P~ITImiddotllt H)~o ill Hl) by ollln( ii lL satishyfaeto7-y l)lp(ipitunt A solution of 1 palt of H~~o to 1 part of H~() (1-1) iI2So1 nnd abo yarious int(lIlIPdiat( proportions of tlllse suhshystanCPs giyp fait 1(511It8 but with till inlIptl(l ill [h(gt ratio of H~S01
~
bull
bull
bull
bull
bull
RAPID PHOTQlIEfRIC DETEMIlXATIOX OF HtBJER AXD RESIXS 21
to H 20 the )olutioll becollles somewhat vbcou5 and precautioll Il1Ult be taken to ttvoid bubble formation When it i5 poured into tilt Cllvettes
It should be lloted that both of these precipitants have an ftellleshymmiddottion It was found that when XHjOH was used in the rubber preshycipitant in pInt of H~~O~ the readings were -table l)Ut were not reshyproJutihk The lIl of XuOH in pInel of H 2SO j ran nHittble result as a llth H(HY(Pl WIWll til( li-P(l put lthatgtl in lublltl llnalysis or H~O illlP-ius anal)j wn-i uddint(1 thl eharalteliti(s of till liquid with pleeipitated ruhber or resiu in HI~P(ll-ioll n ren1 on the lpNmiddottroshyphotometel m tololinlPtprfollop(1 it lPgnlal lIlll II~ lxplaiHd on pHgP-I (Sl( figs 11 aIlIIl) Tid made it lloible to outain lEPJOshydlHibll tpnlt nntI (onplt1J1(Jttly till JpqnitPIl tlPgJPP of PJPcljoll
IIWIE(TI 1lt COl~101J)
Jtl thp ItJiPl middotxlwlillltnb hefoJ thtmiddot -1l]YIlIt allll pnmiddotdpitallb had lIptll ptoppJly adjutp(l it l fOllll tIuH till llP or a Ploltiw colloid -wll ltIi1)cJ [ttlJmiddotntl- imlIopl tll lmiddotpro]lIibility of the lPlllt JmUkllly ()Ilt 111 U lput lUlU illlihumiddot tOJllPOlUtl tpHd liglyeol teltlut( - llpanlItly IllmiddotlfP(] to lit til I1m t IHflll lImnnmiddott nftlr tlH filial prOIptlllll WtlP dlvPllill1 tlll 11lIlpfit (If thtmiddot [llltlltin lollohl wa Hot 0 natlv I1l(lhmiddotd III rlumiddot Ia- of tmiddot ill tllmiddottJmillaritlu it b [1 hmiddotjlmiddot til IIpoundgt Ir llH1 It liltr ill-llImiddottiT Ina lll ptlPII by it U( in ruhhfl mmly j 11If dtmiddottail fOJ tltt lllllmtlllll If thl plot pet in nlloid ~llntill tltlmiddotlImiddotmiddotlttlatiflll lIOlllllllhtiPI1 are iPllllll page
liTFHFEHliG COIOf
(hi II tht lllail 11111111111 that had til ill -111111 II urklll) om tlH method fot lublJtt tlIlO1 rpir- nlalv~i in plaut llllpll- wa ttl (lilll~ inare tIte (gt1[01 till to tIll ptP-PlHt f xi [aIWIIII- 111 TIlt amount of (olor varip from lUllIt tn -amp ]pplwHlI nlt rhmiddot lt IIf thE Hl(ltllial tllP part of till plllIt -lI11lhmiddot(l tilt hi-tlllY f tlll plaut mtteshyrial ~ub-lltInent to Itlllmiddotnmiddot-rill lliI 1011middotly OrllPI Inlw
In ruhlwr lrtl-i I Iii 1101 au Itmiddot 1Iplll11l by 111[ I--r ratmiddottilt thE -lllll]t with uptoIw or 1middotmiddotlIll-ol - wIdell [llllol- rlll loillriu nutttel autI thtmiddot lpill- Thi- howmiddotvt n(tnll- til lXtla -11gt1 ilt prlJ~edun) In lP-ill ltluay-i nllHufldy tlW[t j 11 1 1IO(PIlln fill the 11shylImya of hlulophyll Hwl rIlI-r middotIOII IHlttlmiddotJ dlH lUtl~ In plltIH withoUt alo aiftIriL till nmiddot ulttrll
111 pllIbIll1l Wi tilmiddotr hId h It-ImiddottHI tht Pltlpll 1 hlitlt lilt tlw tulllWlli tollImiddot uIwltllIIntut -lltUIhorlllllltll 1111 tIll tlettlllliIttwr IIf t 111 lWlrl-Uamiddot of bdt tl11blLlittUhmiddot r [1 tItmiddot preshyj
lipitatifll 1lJ llllllWI atbull 1iI- in III -1nrmiddottIi fHlttalldh nlrillU~ amount rf middotlorilig lIUlttll Iii lhll of ih lltmiddottllllhottohttt~l l~ol()r infrtl Hm II upd 1 rwmiddot tld~middottilmiddottll PlllItlhi~ f it j proYitiltl with tIll lilP--UlY tU(jlIdlllIlml tIltmiddotmiddot lllklllUIlI
EIECTIol OF 1 [EGTH~
-Ptfmiddott ral tracilull ru~lI gtIll fr 1 nllb t ~xtltd 1 lIlt-th vI iobmy1 ketommiddot lWtl rill [ Ixt lttltt ll UttollylaIiIitt1l11I1t~ ~-I itoiu YtHil)u~ typp of ~IHaylllt f i lItmiddot art hraquoil ill fio1ll1 ~l Th~ lp-nlt fill I11oohl uio[1t ttl willlr til tltN- fur rht IUiXtIUt iwliutll
100
22 TECHNICAL BULLErIN 920 U S DEP1
90 bull eo
I shyz 70LLI 0 a LLI a 60
LLI 0 50 z
a ENTIRE 2-MONTH-OLD PLANTS~ 40 b ROOTS AND BRANCHES OF ~ 3-TO 4-YEAR-OLD PLANTSen z WITH LEAVES REMOVED ex 30 a C CURRENT-SEASON GROWTH OF l- )-TO 4-YEAR-OLD PLANTS
20 WITH LEAVES REMOVED
d LEAVES FROM 3-TO 4-VEAR-OLD PLANTS
10 A
0
a Cd 100
b bull
10
80
I-Z 70LLI 0 a LLI 60a
LLI 0 50 z ex I shy 40 ~ en z ltI 30 a I shy
20
10 B
o~__~__~__~~--~--~--~--~----~--~--~ bull350 400 450 500 550 600 650 700 750 BOO 850
WAVE LENGTH lM~)
FJGcm O-Sll((middotlllll tramaniW1IHl (mrpS f(JI (xlmll 11011 n J1ll of jlta)nle tissur ill n 2--m1 Y011111P of (A) Illrthyl ji1I1J1ltsl krtonp 1111(1 (ll) nt(middottQnyla(umiddot tClIc-C(l1osuln a-i
bull
bull
bull
RAPID PHOTOlIElRIC DETEH-UXATroX OF ntBHEIl AXD HEstxs 23
ThE dula Pl(S(l1t(lltl indi(ntp Ihut 101 Illp ulimls llHthyl liohutyl htOlIl (lxtrHts (lI(I r(dolls of Il1Hxi11111III nigtol]gttioll wiH1I all (is-lIb 11 cOllsic1(]((l n1( blhn(11 wn ( ItIl( Its lIO to () I1It~ nlid Ii to Iii mJL
WhllNIS tlw I(gions of 1middottnL(s( light 1lnlllittamp al(l lgtPlW(PIl wan Ipllgtltsnr) to Ii nllt jW) 1I1JL nlld alio Silllill1l 111l1b (n SI(lIlId 101 nc(ton ]altmiddot(fmiddotollp-(llloolp ~ pxt Ill of 11a 1111 t illl TIl( (1101 du( to lolo ill tlw litlltitl a 1Il1 lullll(I tH lPill- hanmiddot bpllI PI(_ ipitated ma he 1((I1((d to fltI ynbhing poillt II ph( illg OJ illshylmiddotJall(( WIWp balld nhm ()) IIIJ1bullbull[1I111 lxjlPIitllll1b Illln -h()1 that Ih( lIIot uilahl( WHYI lHlIJ fOI 1-1 ill 1l11J1l(I HIH11Pill- illllllrsi i-in till IlPighl)()lllll()(l of ~llIl1lt bull
bull UIlIilHlIy of n typhn] lXPllillllllt to )10 l1iP(tiP ((JIlllo( of (ItOIS dul to lOIOl in 1llblnI Hnd Iill xtnumiddott 11(11 IIIIolp t jUl i p1llelll((l ill tub]lL Till llhlllt- 1tpIO]II Hnd ((llll~()h whit-h UI(I ](]Hllilltl n 1I01lllIhb1 01(111 lxt 11111 IIll 1llll)1 nmtp[in I and )(middotills Tid IIlnkl it poiblp nftlI tlIp uplll1tillll or tlll o1PIl( (0 [niH lip 1Iidl1p~ of lI111 11111(( ill lit ll11l1)[1 (llnlIb nlld Ihll
Sl(ll n ol1lliOI with tllP olnl IJllt illiollt HIl Iltlllll llllI (Ill ltllthpl prpipitnnt j Ihll1 nddld OUI ha a lIilPt lP( of till lIiciPlw of WH( lllIgth 7) lUI- ill llilllillatiu (nnl till tll Ixtll1I101l ()lll~
Tuu tmiddot-Elilll IJl flrldillY 11-1111 lrlllI IjfJI til islII 1 1(1 ([rllt IIIIIJIlIr JiIlIt~ if 1Il( Ihll 111111 k til I III Ilrln I 1Intd tf 11111 JiSf fill I I II I tIII Ilf Iilltl 1f1JlIIillII1f I Till 1[ 1 IId 1 (I (middotIt 11111 (I1I1iI1 1lf1IWtlfJlIIllfflr p middottrllhIJ11 II J III 7IImiddotIa 111 111 lilt jJIp 111 wilTII
t~t tnVIli~ ~nn r kn t~ i tmiddot ~~l Jr 1middotmt ltlTt
HmiddotOtt ~I~ lin t I ~ 1 t~~l ~qrmiddotthtmiddotrtwb
Hult-middottltlru t T Hw ullut rHtt~ r II I ~ PH~lllt
A~tmiddottHHjmiddott~rjd rl ~gtllh 1 tn~th~ ~ ~ middotI lt~ b w bull hmiddotth~ 1i~lIhun 1 Ii tnl Illd1 -11lt1(11i lullI lUI tJl ll~ t1~11n( I Ihan1li flfttIJir Ult I Uuhtltt ahuul l(hmiddottHmiddot~t trv r fti HIt lftbyl tlonhUt)1 k_hIl( 2 m~ fmiddotf tuhlHmiddotr In mlth~ llmiddotlf- 1 t r
t r_~ t j
Arhlitlltd ~llIIDHl NcWitn1 ( Ar-(lt()nc~middotttrrtrt ritJJI~ -Iu nllJtl4-middotr
ACtmiddottflnp fmiddotxtrn( ~ T-P511ftf tn mtmiddotth~ 1 ~difmiddotut~ kdn 2 nltt ulruhhtr in Un-tIl lltbu )J~IYt
rUth(Hl~hltlft HhubU
Illlh(I(t tttUtUt hUbtl til J ~jlitl(J Hilllll trtIIImiddotjtl1ll
(UShl I ~tlO wHllolH rulh r (middot1111$0]( J~rru t t )lthyl 15bullbull1middot1101 klll1l
Ili( UHUicbcul ~((i1rUtl ~ulu1iin 1middot lIUIll Ilti lrllltlllt I Ruhhr llt1thuI r1 -1 Irld
ltlt1111Sh 2 nuz f)rruhl~rm nlith~l tu- h f nt nil~middothgt(H] tlrlftmiddot 9lUtirtl middot1 1
rlcltfl( H(l dnllltml it
(IISllhH~rI( Iultruhtr CII05 1v ltTlft I 2 UI~r ublwr In llldh I hlt~1 11) lgtjdvr(llsl~9rlltmiddot middotlmin ~ I~ gt AIHItilltl no IrttipHallr iI
~ Bbnk 10ol m(thyl i~tmiddotut~i kdHn H 1 m1 j~~ l1rH-t lt~tlfltmiddotn sf n it ll HltlMjftr~nol O2~mlJ ~U~1o-ulp ti~tW -xtra~middotl(lt1 ltt 411 ml bull ie f Ct- kft rt t~ tirattJ middott ill r u l1kn ttJt
in metltl isobutyl kNqnf nn~i mljp ur tmiddotmiddot ~oml ~urr tttl i t w ltJj1JH kt 4t 3 nlank 1 mL((l1t~rthmiddot(middot mI mttr~ ~but a kmiddot tmiddotc d 11 ~ gtli~b~ hifIAft- fl~ lL lnti 149
ml8(dlfilll BO bull 02 gm guayule U$Stl(middot xUlClt-l tf(h tft wI n nmiddotmiddotmiddotlgt 1 lznt on tmiddot ~Jt r~1 ~~u~~ H~ iI~ thT
24 l$CHNlQAL BULLETlN l20l S DJltJPT OF AGHl(CLlOHJltJ
In table a is pl(sentc(l such c1il((t edlt1tIHC showing that thc (0101 Ixtrnetccl from guaYIIle tisslIe wit h II(P(OIl( n nd (pl1oso[yc is cll(div(ly sCIe(nec1 out by the s(lp(tion or wnw length )0 miL Oil t1w SI)((IOshyphotonwtpl This tnb]p all-HI ihos thai thl Juhlwl altl(l((1 (nn IJl quall shytitntivcly 1(I(()(Ipltl in tIlt PI(ilIH( or Ih (o]OIplnwPIials and Illsins and tlmt Iuhb(l WtlS nppnlllltly 1I0t (xtltI(((1 110111 11l glll1I1l lisslIt b~ tlHSP SOhlllts Thls( ((suIts ginmiddot (OliIHillg (idJt(( that t Iw IISI of waYl llngth i)ll 1Il) OIl till SppdTophot OIllltPI ii t hl 1101(1 p(oshy(ellule in photolllliTie IlIlalysis of luhhlI OJ l(sin-
SELEGTIO- OF )IOiOCUHO)IAIIC ItIIm ((1111110
On th( basis of th( IPHIlb shoWIl in tabl(l 1 al hlllpls (1( IIln(lp to SPCtl lC the PIO]Wl 11101lO(lIOl1ln til Ii ltlJ ((lIllIJi nIl ions 10 llIiOlS (oIOlimet(Is 111(gt 7W-Ill~ filtpl flllnhwd 101 til( I1~lI1l photoshyplpct1i( (o]oriJl1ltll fol which Ill( (hlll(IlIiitit~ oj t hl Ilda he light ilUIlBlIIhiSioll (t) elll nn -hO11 ill fig1lle 10 iws satlsfa(lolY IPshysultl 111( iiO-mL HitlI olllhintioll 101 whkh ttp (middotIatinmiddot light tlnnsmission (ullmiddotis a 1-0 showlI ill figllll (I is -nthdnlto1 hut this is not stnlHlnld NtllipmPlli
Up to fhl PlPHllt lIS(middotflll pound11((1 (ulllbinntions jn lltl iOO-I11L Iunge hayc nol bllll SlClIlld 101 lhp Klpt 1-1I1l1I11PISOIl (olOlinwtll bu fnltlwl nttCl1lpti 1( )(illg IlIHd
TJIpound OF ST~lmW AFTEH HIIJ1EII Oil HHSIS rlll~CIIITTI(J
~ considl1ltiol1 of ttp lillll of Inlllling af((1 plpeipital ion of 111gt)(1
01 l(sinSTlOIll ollltionis impoltant J(jl~ thC1HI(Plltngp of light IInIlSshy
11 rshy10 f shy
09 f shy ~750 Mil- DOMINANTI
~ 08 cshy I WAVE LENGTH z
I III III i O7 - I III
~06 - 05 shyw
a
Igti= 04 - 720 Mp DOMINANT ct WAVE LENGTH- ~ 03shy
02 f shy
01 t shy 1)O~~~gt~- J 600 700 800 900
WAVE LENGTH (Mp
bull
bull
bullFIGlRt IO- COJllPIUlItiw ~IW(middottltll tlnIlRlllii-lion (II (IllP( 101 1i11(1 olllhinulloll
with dominllnl Il(lllllgths at 720 and 7iO lUi
bull
bull
bull
HAPlD PHQTQlfE1IUC JjETER~lINATION OF Rnmrm AND HEtiINi 25
mitted (spertrophotoll1eleL lCuding-) Ol light (1 (tClcrl (phOlOshyJluol01l1et(L lcndillg~) i~ StlhjNl to (hangl
]fjt~l1le 11 and l~ show that ill til( (asc ot tJaugtIllitteltllight llJHC th~ (x[llliHlllIlnl (oIHlitiOllS tllpl j lilst n dtlln-e ill Pll~(lltngl or UllllslllittnlH( follrnY(l by It ptJiml of lClntin stability with only sliuht (1111 tHn- a f(Pl a lIt1ll1btJ of minutes The light t UIllllitblllll t l(1 ill(Iln~(s This lIIay IJP llllllJltlli7P(ll1 ffl II ow 1Ilt )( f(( darI oliIII tIIlIlNlIlitt(IIIlfJIIlh (iditilIiid Ilil1 pllIipintnl )uoshyIn Of ( 8inx in (~f1( I~iUII i~ Ild stahl I 11 itlll If 1inl nh prlshyilli(ioll of 11l1d(1 II IJIX f) jllIli II (fJJltfiIIlilty slllMI IIriot 1) IIIPldUnl1i tll(I1I rllltltilJl oj tJi~ Jlt jiot IUN ilUf Jxl1 will tIt( tOWI IItlllilil I 1llIlllblJIol I ill I~11l11111 d ill till ifjuids JjOI scnttplltl light 011 till phololltHJIOIl1lttl till dilPCt ion 01 elangl b tlw IPrfIi (If that illrli(atPll rOl tlulll1Jittp(lliuht It Itlll b( llluliJr I-(Pll that if l(middotndlnJ- IIIP mad n itl I t lIP ~()ll1d()lb lpalll this pllioJ of nmiddotlatirp tuigtility tllP llLot tIOllt thi Olll(P (nil bl IPdUCld to tIl lltini III 11 Ill TIll l~adiltg (illH~ bbll Oil tlHl datn rUl lublwls and llsinlt Illl ginll ill tnhh
50 r----------------------------------------------- f shyZ
~ 40 ~----~W~A~V~E~LE~N~G~T~H~7~5~0~M~P~~~~ ~ --------------------=-=-= ~ 30 f- WAVE LENGTH 540 M~ _z _____ ___ -=- __ _ ~ ------shyt ~_=---=-=--I GUAYULEIII 20 -Z HEVEA ltt II KOK-SAGHYZ f shy
4 6 8 10 12 14 (6 18 20 22 24 26 28 30 STANDING TIME (MINUTES)
FIlirtn 11 Emmiddot of wav hll~rh Il li~ltr tlall~lIIit1alHl aftI IUIlItHt -Imlli lug 111m for guaynh llmiddotn 011111 middotiolIlJh~z 1111111 llijlitul1 flolll 1lHlh~ll1Jllryl k11II11l ~(lilltlll h~ lwitlitll 111Inu1 111l~1It1 2)1111 o1U11111 (Helillins on (illllun tlunhll IlIIJlllw]ntllW111 lutl(I[lholtllllltlt with ijUjt Wlnl IHI Ilf1 I
11 EFFEGT OF Hbli 1 -()JXT10~
Tilt lnblwl ~()h(llh pxtnl( till IPillgt ubo It 1m nllu1- bellt -~atea thut ~lll 11-111- tUP olnbhmiddot ill middottIIlIlOl ~1It tlWIIJI( my U)t PIl (tlIHatcl WIth tl1l lullh(t I tahle lJ 1hln 1- -1111 tIll (llllstlOll of nny p()~iblt tITptt of XtIIl11 diflp]lws ill ((JlllPllttUliollS of 1l-in lil lolutioll alollJ with till 1lIltbpl TIU data ill wbh +ho on tIl( hn~is of (olorilllPill ladillU thaI tll( IIUOIl1t of lnbbll Plllipirntld 110111 Ilwthyl olnlld kptOlll olntioll IJ 1li-jHlllnt 1l)04 in 1-llltlIllt ethallol)- not amlll hy thl llllNlI(l of llvin aU1ouut of llins inolution bull
-----
26 rECHNICAL BULLEfiN 920 U S DEPl OF AGRICULlUHE
100
90
80(I) C)
z Ci 70 UI a 0 60 a ~ UI ~ 500 ~ 0 I Il 40
30
A 20
0
100
90
(I) 80 C)
z Ci 70 UI a 0
60a ~ UI E 0 50 ~ 0 I Il
4-0
30
B 20
0
--
--shy ---shy---
2 4 6 6 10 12 14 16
---shy= ~ ~ shy
-
2
025 05
10
15
20
25 -30
35 40
SO
-60
=70 80
16 20 2224 26 26 30
OS
- 10
IS
20
2S
30
35 40
-50
-60 -70 -80
bull MGPE 25-ML
VOLUME
bull
MGPER 25-ML VOLUME
Florm 12-EtTld (If till1l or Slllldill~ 011 light transmittallce (01 (A) gUllyulc lnUIl(I plccipitllitd frOIll llltt h~l isobutyl Ielollt solution Ily neidilic(l ethanul bull null (B) gUllyule ll~illii pre(ipitated flom aeltoll~lllcetOlll-Cl])osolY( 3-7 solushy11011 by H(illilip(i l1U (HPlldillg~ nt -lIlillult Ifllpluls 011 Evelyn photoelectric colorimellr with jU-lllp tlllll alit U-1I11 npN(lle spp also table 2)
bull
bull
RAPID PI-IOlOMEllUC DElEnMINAlION OF RUBBER AND RESINS 27
TADIbullbull ] 4-ReZation of amiddotmount of middottbber pleeipitate(Z Oln metltlIL isobutyl ketone 80lutions by OS-pereent H 2SO in 95-pere(lIIt ethanol to umollnt of resin8 udde(l U8 indivute(Z by colorimetrio readinU8
(Rubber ami resins cnlculntcd on bnsis of amounts in 5middotml ullquuts of extract from 02 gm of tissue in a 2fllll olumo( bull
Hubucl r~cocrell whcll rcsins nddcd as IndIcated Htbbor al1dcd (pllcollt) ---shy
__________bull_________ ~_12rpcrc~15011crccllt 7511crccnt IOOpcrcent
PerCtllt ercellt Percellt Percellt Percent o o o o o) 50 250 263 252 25000 500 500 500 500 700 750 750 751 749
1200 1250 1250 1250 1250
EXTRACTION TEMPEHATURE AND TIME
Typical experiments to detllmine the time required to secure maxishymum extmction of rubber und ltsills at 115deg U Ilre sUlIlmarized in figule 13 the solvents used-methyl isobutyl ketone for rubber anrl Ilcetonylacetone-cellosolve 3-7 for resins extraction-are very eflicicnt since under the conditions indicttted maximum values were secured after 30 minutes of ext1llction The most eflicient liquid for the bath (lig 1) used in extrtlcting rubber or resins is ~ high-grade cylinder oil (S A E ~O) The sand bath and such liquids as glycerol have proved unsatisfactory
RUBBER AND RESINS STANDARDS
According to the National BULeau of Standards 1-_ lhclc Is no gellcrnlly recoglllz(d standard lIIutcrlul [ior II rubber standard] The rubber hydroCllrbon ill llifferent samples of conmlcrciul smoked sheet or pale crepe from heclI pluntlltions nries from l~ 10 04 llercent of the totul nutletmiddot the most 11Ioruble conditions Of preparation
McPherson () has described a procedure for the pLeparation of pure heve~ (Hevea brasiliensis (H B K) MueH Arg) rubber from crude rubber or latex In the absence howevcr of ~ generally recogshyn12ed stalldard for rubber hydlQcllrbon [caoutchouc (CnHUs) xJ the standard adopted was that of the relnthely pure product secured from gunyule tissue txtractiotl nccording to the Spence-CaldweU method (5) or the motlified PIOCCdUlU of Hohnes lind Haasis (p 2) The details for constructing the calibration CULes are given on page 10 Standard rubber samples apparenl-]y can be stored for a long timc under the conditions des(libed on page 10 The duplicate colorimetric lendings for glULyule rubber newly extracted by the modified SpenceshyCaldwell method were ()J2 ench as compared with US) each for the sample extracted by the same method but stored 1 years In each case colorimeter rcadinllS were made on mixtures containing 2 mg of rubber in It 25-1111 Yolume
The selection of tt suitable standurd for guayule resins presents some dilliculties Tll(~ acetone extract of gUllyult estimated on (l gravishymetric busis~ for instance proved to be variable depending on the type of tissue sampled or season of sumpling because such fractions as
COllllllunlcntion dul(lt1 Octohtr 22 11H3
28 QECHNICAL BULLEQIN 920 U S DEPT OF AGRICTTIIlURE
16~==========================115 shy
14 bulli= 13 z ~ 12
ffi II Q
10 c w 9a w
8gto () 7w a
6a w
5en III ) 4 a
3
2
A 00 5 10 20 30 60 90
14~------------------------------------------- bull13
i= 12 z w II ()
a 10 w Q
9 c w 8 a w 7gt o () 6 w a 5 If)
z 4 If)
w 3 a
2
o+B~~__~__~____________~__________~ 5 10 20 30 60 90
HEATING TIME (111 NUTES)
lllGUltE 13-lDffect of time o( lICntillg O2-gm samples of gunynle tissue with solYlIt nt llfio C on lo(OVl)ry of lllhlJer alld 1Isim Lt HlIhblL extracted with methyl isohntyllwtone B resins Cxtll1cted with aCftonyla(etonc-cellosolve 3-7 bull
chlorophyll are weighed along with the resins in the acetone extruct but are not estimated by the present photometric method (fig 0) 1he use of a diffeJent stanclttrd waS therefore indicated
bull
bull
bull
RAPID PHOTOMETRIC DETERMINATION OF HUBBIm AND HESINS 29
The resins standard selected is based on n relatively pure source of resins the rcsinous exudnte 011 the stems of guuyule plants IJldimishynary expeliments with the resi nouS cxuclate from diffcrellt gllayu Ie strains of various ages indicatc nHlt there is little YaLiation in this subshystance on the basis of Colorimct(r readings 011 2-mg aliqllots of 01shypercent solution in It 2i-ml volume (tabl( li) Expelilll(lnts have shown that the air-dried (xuclate contains 3RtOH p(Ic(nt of -volatile matter This material is l(latiyt~ly stablp ill (OlllpoBition and is npshypurpntly on ly slight ly hygroBcopic as shoWIl ill Ia bl(1 1 Tlrp Ipsinolls exudate may be jJleplpd in two wayi-i fl liSP as a stallClHld-(l) the clpan exudate is clripd iol Ghouls at ()1deg C at W indlPs of a(lIum Hnd aftclbCinOglOund ill a molfalis 1)I(spI((I intn airtight COllilinel OL
(2) tllP Cx7lclate is clissolllt1 ill a(lhllll and filtplpd PlactieaJlyall of the acetm1l is thpn lYapolntwl olt OPI a stlam or atCt hath and Ow residue is dripd ground an(( PI(sPIld as ill tllp fin lllethocl Tlwse two prepalHtlolls a1( (ompalpd in ta hlp ) 111( (((tails fOl ~t()lil1g the resins standald and (onstlllcting the calibration CUITPS alc given Oil page ]2
lAIIIg fi-CUIIIllrsoi (lJ lIr-dr(1I IIIIi 1((11 II II-()I-tr((l l(sil~ 11111111(8 of I II 1111Ie
[Colorimetric rrndill~s 011 1~I11 phulll(Iclrie eolorillJct[lr with i~()middotmll (100- to iiOIIIIl) fillcr [lnd 5-1111 lIperture preeipitantl part ofO5middotPIrctllt 10 to 5 paris of IIOj
nupliclllc(oloritwt([
nIl(lin~s (hIlSlcAg~ ofSlmillXo JrNliltlCllt of fPsiJI$ L1Xtlrlntp on 2 IIIg ofplanls fllsins (XIHIIlt~Jwr 25-1111 vol
tII1(1) 1
leflTs Various _ bull ____ bullbullbullbull 3-9 Colll)Josiltrlairmiddotltlricfl bullbullbull nf)2 002
])0____ bullbullbull _bull __ _ bullbull ~-l Composilld (ri d at n5 C in aUmiddotimh lWUUllJ for l (jOuj(ja hours])0______ bullbullbull __ bull ___ bull 3-0 COJIlpositld disso]NI in neptolll f1l1erNl fl(lf()ll( GGO i(jO (Ivaporntld olT OV(1r Stpl1l11 halh TesidlH drl(ld I1t fi5deg ( ill anmiddotinch VIl(Unlll for 0 houlS bull
middot106 __ bullbull _ Jir~c1rild_~_~_ _~_ ~_~ _ ~ ____ _ __ _ OUu GOifina_~ ~ _ ~~_~ ___ _ _fln~ ~~ ~ ___ ~ __ 6(imiddotI tiliA H)[_ ltlu bullbull i18 tisSflOabullbullbullbull__ bullbullbullbullbullbullbullbull lt10bullbullbull _ tillO llitO406__ bullbull __ bullbull __ bull __ __ lt10_ Utl2 fon591_ fo__ bull liGa oOa 406bullbull _ __ lt10bullbullbull_ li5S OM
j Ph( vnluls in Uw Inst COIUIIlIl indieatp thnt gunyulp fesinous (IIHlnt( wlwtlwr dfircl hi Yn(tlLJ1l1 wilh L~ perc(nt loss of volntllt wutl pr or tWl c1rild giVPd npproxil1lnh1ly t Iw snllw colorinwtCr rNHiing- 011 till busis of aliquot~ cOlllniuiug 2 IJI~ of flsillS lXIHlntp l)tIf 25-mI volultl( Ihil- illdicate~ thl11 Uw UITW IJ1flS~ of olnshytile mntl(f prt~(iJlitnt(d gins npproxilllntlly Uw $1II1l (oiOfirnl1tlf ftudiTlJs ns tho ftsidtw A pnlill1jllaf~middot (XIlltrinllnt indicutls thlli th VUllltill muller l(lIlSists of thl Ilrplne oil fmcl ion I5-(1Il gtnplls or rlsitlOtlS (lxudntll gnvll by stPll1U distillation nn Uefllgl of 011111 of jl(lfPlIW oil with npproximHte tilllsity (If OHIi lind lhus rrprlsll1ll( IlPIJroximllt(I~ 01 Jerccllt Of t he original weight 1hls lllrClnlage complrcs wllh 38 llltrC(ntlost by drvinI( in IICllnllJ
aSplusmnUH perceilt or orlginlll weightlosl
The wailnble illfolJllntioll on tlH (ow-JitlPllts of the gunYllle r(~shyillOllS exudate alld tl1( HeetOlIP ext act of gaylp ti~slw is sllIllmarized in this paragraph lYalttI (u) alld also Hangcn-Slllit lind his coworkshyers 16 reported that 20 percent of the resinolls exudate from gUltyulc stems is parthenyl cinnamaie (CHuOH=CHC020 11JI2r) Steam disshy
15 (OIlIJIIIIUicatioll flom A T Haai(II~l11it llId (0011(11 Calif0111 ill Tnfiitnte of Tccllllology Past(IlIJI Jhps( wOlken al Htud~ing the COTlHlitlllllts of the acetone extract and other conlltituellis of guuyule
30 TECHNICAL BULLETIN 920 U S DEPT OF AGRICULTURE
tillation of similar resinous exudate in the writers laborntory has yielded approximately 4 percent of the whole as the telmiddotpene oir fracshytion Haagen-Smit and his eoorktrs nportec1 thttt about 25 percent of the acetone extract from guayule branches is parthenyl cinnamate and 6 percent of the bark (ltortpamp-phlotm) extraet is parthenyl cinshynamate These workers fm-thcI reported that 25 lwletnt of the nc(shytone extract frolll bLllllches is a compound with the tlI1pilicaL formula CBoH400a 1 percent is a compound llwltillg at 2P to 2T5deg C and 1 percent of the extract from the ]eav(s is tl (olllpoulld nwlting at 100
to 1710 1Valtei (6) reported that 3 to -l perc(nt of the tI(eton( txtract
of leaves and flowering StPIllS of guayulc eonsists of waxlike substances soluble in olgallic soln~nts but insoluble in at(l and (on(ent1llted H 2S04 The flactions mentioned on the basis of (onHLTutle esti shymates of amoullts actually isolated tlecoullted for about H ptIcent of the totalncetollt~ so]ubles extracttd from tll( guuYllle 11 rub The other constituents ltlilaill to be i(](ntifi(d
RUBBER AND RESINS CALIBHATION CVHES
Typical culibndioll Clllves iol Iuhbpl and I(sins bas(d 011 (ldtLminttshytions made nccoLdillg to the plocCdmC outlin(d 011 pages middotb to 1G arc shown in figulPS 5 and 1+ The spCdlopliotoll1lttL en (OIOIjlllctCI readings are plottCd on s(lIlilogalitllllliC pappi ag-ail1st (Il 11IbblI (011shy
100 ~ 90
80 ~ 70 ~
z 1amp1 0 II 1amp1 IL
1amp1 0 Z
60
50
40 ~ltI 30 ~ en z ~ ltI II ~ 20 C) ~ oJ
10 o 2 3 4 5 6 7 8 9 10
RU8BER IN 25-ML VOLUME (MG)
bull
bull
bull FI(lURE 14--Ctlihration curve fotmiddot gllftYlIlc lubb01 (Hct(lings Oil COIPIIHlII tlOl1hl(
monochromator SlCClrophotolllet(r with 7fiO-11IL Illtel alld Hllp Wll ( IHlll()
bull
bull
bull
RAPID PHOTOMETRIC DETE~MINATION OF RUBBER AND RESINS 3]
centrations From a casual inspection of these CUlTes it would appeltr that Beers law does not hold Actual tests indicitted that Beers law was applicable only within a narrow range in the upper portion of the curves The analyticlil results on the basis of photornetric readings nre therefore calculated by direct reference to calibration curves or from reference tables of equivalent values bllscd on the cnlibllltion curves
Calibration curves for kok-saghyz alld heyea lI11tulltl rubbers and Buna S (GR-S Chem Gum IV Goodyear) and butyl (GR-I Standshyard Oil Co Protoc) sYJlthetic rubbers are hOWllil1 figure 15 The samples of kok-saghyz rubber were furnished by the Diyision of Rubshy
100
90 ~I) ()
z 0
1amp1 a
~ a
80
70
60
s 1amp1 ~ ~ 0 ~ KOj-SAGHYZ 0 l Il
50
HEVEA~ ~
40
100
90
~ 0 80z Q 70a Co)
a 60 ~ 0 0 x 50Il
40 ~----~~----~------~------~------~--~ o 2 3 4 5
RUBBER IN 25-ML VOLUME(MG)
FmUIlE 15-CaJiblation curves fOl kok-snghyz h(YCII Bunn S lind butyl rubb~ls (Readings on gy((yn photoelectric colorimeter with i20-lIIp filtpl and 6-ml aperture)
32 TECHNICAl BUIJLETIN [)20) 1 S DEP1 OF AGrnCUIlfURE
Iwt Plant JIl(I~t ignlioll of thi BlII(un and (1( l))(parcd according to 11( SPltI1((-Culd (]] (6) PIO(((lllll Hlpt pal( CLPPe was (xtmch(L with acetone blI()Ieit W 1I(gt(11l a ttnlldal(l
SEXSlllVllY Ol~ llETJIonS
By lip pIO((l(II11P olltlillP(l 011 ]Hlg( +n Iowa (lOOl IIIg (11 1111i(l0shygmm (gHlllllla) of 1hblI ill a 2)1111 yoltll1ll (all )(gt dltpltld Oil tltl Col(man (lohlP mOIlWhlOl1lHlOl l-I)((t 101 l1lOt 0111 ci( I ill1ilnlly 001 mg of Iublwr ill a 2J-1ll1 n]ulllP Illay bl Ilad Oil till EnI)1I photoshyllectlie (O]oLillllt(I Thll ya lllll- 011 tilt IHl-i- (J I (xl ad iOI1 fmlll 02 gill of til-lI tH(JI(lillg to tllP -lllndal(l jll()(pdull 1(PIPStlIt IlO()2J tlnd 002) P(IT(lIt of llIbl1ll IPI)(((inly bull1t1lollgh -lI1t low allils can be d((d(middot(1 il lIoullt1 Ill IPtllizpd thnt till PIIOl ill PlI(Plltng( or tll( al110unt dltlIllIilll(J i ltlatlpl high ill tili PIY lo Itlllgl 111 aetllllllladie(middot Ill( lopl lillliL 111)(1(1 lIw (ollllil ions of tlil ]lI()(lltlIIIl u ol1tlinpd ipt at l11 11I1 or 1111gt11(1 illt i-1ll1 Ollllll IlPIPltPlltillg 01 p(gtl(pnt of JllUiJtL un tlll 1Hli or (xlla ion rlOI11 II rlll of tisSIll
EIlIlOH COSIIlIHIIO
In Oldpl to H(IIp ill )1lHtPltt pl((iioll illlpIi1I- it i lH((SSHI to slnlldHIdiz(i rigidly 111( Pl()((dlll( 0 illdi(ntpd Oil pnglt- - to J( If lids i dOlH tlip lXIHlinwnlal PIIll is t(middotdllld 10 n ndninlllill
Illlt pl(iioll of (hI ]lIPPllt 1IHllwd Oil til basi of ]llllP llIllJt1 alld Ipsinssollltions call hI jlldgl(J 110111 figllll Hi lileh lio- til HPIlIgl d(intioll oft -illgIP lI1lnSIlIlIIIlnt in lHi((lltagl of Ill( alllOllllt 01 Illhshy1)() 01 lpsins d((PI1I1 iJlld TIl( (1101 PlI(Plltaglt H1( gi (1 101 OJ) to
RUBBER IN 25-ML VOLUMEMG) 004 01 02 03 04
i= I I IZCtOW
fbA ICtU CtCt WW a
01 02 03 04 05 06 07 08 09 100 = RUBBER (PERCENT)
RUBBER IN 25-ML VOLUME (MG) 10 20 30
~ I CtZ
bBOw Ctu CtCt Ww o I~
010 50 100 150 200 250 RUBBER (PERCENT)
RESINS IN 25-ML VOLUME(MG) 10__ __3-0_ 40 50 60 70 60 90 100--_-- 2_-0
Ct~ -r- 1 I OZ
WCt UCt b C wCtW
a o I I 150 250
RESINS (PERCENT) o 10 50 100 200
bllI 1tI W-Yllnl dtd1 ioll I I 11l1 11IlI11 1(111(11 1 III Plll- IlIIIlol1 01 IIim~
bull
bull
bull solution Il basis J o golH of tiSSII (JlILCl-nt (11(11) for (~I) (l)1 til O 1I1
of luhllpl lin 1 III I (I Ill of lUhlJPl nllll laquo I J to 111 nlg of IlSlllgt (Itllillgs on ]iYllyu pllolwh-llrk CO[IJlilll(-(PI with nOHIP Iiltlr lIntl U-lIll allcrture)
RAPID PHOTOlJElRIC DELEHlllNAllON Cn HUBBER AND H1~SINS 33
10 mg of rubber anel1 to 10 mg of resins in a gJ-m1 yolumC For
bull
bull
bull
comparative ptuposes the leslllts arc also calculated on the basis oJvershycentage rubber OL tltsills in 02 gllI of tissul As WOlllL be expcet(d the error increases sOIlHgthlf for 1(lali nmiddotly low COlHell t1llf iOlls oj rllbbeL or resins The curves in figure 1(j s1l0 that ill til(gt Illlge Ol to 10 pCrshyeent of lubber the elTOI rangts Jroll1 abollt Ll to II) ]IlC(lIt abo(~ this mlllc tIlt (ITOl d(((ts(s to (ollsidlItbly ltmiddotss (han 1 1lICPllt of tlH mllollnt ltl((Lmill(d Hil1lilally in tlH (lISl of l(sins analysis (fig 10) the ltLTor is (onsit1eIubly INS than 1 PlLllnt ill (he lallgp of 11 t~) ~() penPII t
In nil ([lSl of lllhblI alld (sins lx(Inltpd tIOIl1 (issups Ol addcltl to tisslle lxtlads (s(( tabhmiddots (i H) illyolillg ll01P o(lllntiolls the eLI01
is hig]wl thun that indilHtld in figllll ((j Im pUIl Ill )])p I tllllllsins solutlOII
COlllUCIIOXFOH IXSOLl-IlLl~ Ilgsqgt(Jg
111 th( Jllo(pdulP ollllillPd 011 paw I till illsolllhll isSII Ipidll( tflpl (xttlw(ioll is (Ptill tlw lIask l(lll till xtlct i l1wdp up to yoltlllH It is not rOllPllipnt (0 IPt()PI qWlIltitati(Ir III(lw[olH a 11(1 pllooll extlnlfs of guuyull I is-lll alll thl1l main t11l111 up (0 YOIUllllmiddot bpCaUHI sllch all additiollal stltp wottld]) tillll-C(JllS11ll1illg Th( Iogiea nll(gtIshynntin is to mnkp tltl lXtlUCt Llld Ipsidup lip to OllillH in till original flask andi llPSStllY 10 llwlno tl OIIpdioll wlHIl (allIlnting [hc llshy
Hults f(JI [hl oll111lC displupd hy till ins()lllbh llsidll( III it l)picat (IXpednHllt (ollsisting of Jhp lppJiea(iolls if was Iollnd llftt at ~iiO ( 02 gill 01 Iuhhll pillS IPill-fl(( lisslI(gt (lollpdll fot llwistUlC ou basis of dlyillp ut lOW 101 ) llOlll-j (lbp(ld only t~ llllUll voiul11P of OOk7D~- OO(lOO(i Ill of lllthyl bolnl(yl 1lIOll( (lplhlli(al-t(Tnltle sp gl () Ii I ll(Hli (j at ~)) -gtitllP tl1(gt 1It101111( () r t is-lIl xt Iadld j sl1lall til( PlIOI dul to Ill(gt insoll1blp Ip~idll is slllall III [0111 ill( wOtk it (all lJp diIpgal(ll(l
]hcon~lIY OF HllIllgl AiO HESIS AIH)gl) TO EXTlIACI OP
GlYlLE TISSlg
Tnl)ll G L(IHpslntillp (ypi(nl llld(~ SllOS (hat all a plngl of HIOK PlI((nt ot lltl pltl( Ilhl)(l acldpd to tllP Itll h iolJut1 InmiddottcJllP xhnet
of guayulp tiSI1( WllS 1l((PllIl Tlli nllintioll flOlll (olllplpU I((OYshy
PIY i within flll pxp(IiIlHuttllIIOI ~illli]llly fnbll Ii llows thn 1111 llYlIUgl of 1O(1~ ])(I(Pllt of gllllYllII 1(-i1l- add(d to II( (pllosol( (xshytrae of IUllY]l t i~HI Is 1l(oPIPI
THl~ (~ Hf (Off Ill of 1111)( J OJ I~il~ lItfI(( In ~(JI1IJk~ Ilf (111 [lI1Il fI2 lIII
0 tlUfllllit i~~I1
Instrument
---- ----~---- bull shy 1(1
Colemun ruono~ltrOUlllt()r 2t) II sJl~ctroJlhOL()lIIeter with 2tJ I iflllllI wnclength Fetting 21 II nntl 0-1111 WU HI hUJl(L _ L U
Ill 7Evolyn photo~lcclrie (olor JU [ imctcr with iO-llIl filler IV (I
H1 0 t I I
llImiddot lUn WII 1011 HIO Wn mil lUulon
10 JIg1111 IUI ml lUl anh Io aLn 111)_I ) III li lU It 2) deg wn2SU DD
Irl JIll II IIr II US II
1110(1 lULa lUI IlK) IJ WU
I( llI Htl tNI 1(111 2tlNI HI 0 221) lllil t2S 0 1~ 10 1~13
In (I 2117 I
10U 1l(J ~ 4 _H_j ___
9middotJIlJ5 10115 10 00 lUU5 flUU 4li (tl03 9(11)
leIlKl 1l~)5 lOOU l1KIr JOIS un 003 OIl Ii
34 lECHNlCAL BULLErIN 920 U S DEPT OF AGRICULlURE
COMPARISON OF PHOTOMETRIC A1D MODJIoIED SPENCE-CALDWfLL METHODS OF RUBBER ANALYSIS
Guayule samples were analyzed by the photQ111etIic method and by bull the modified Spenc(gt-Cnldwell mcthod The values in table 7 represhyselltativ(I of typical results indieate It -atisfactory dcglpe of conformshyjty between the two methods in thl range of tiSSlHH with llHHC than OJ) percent of rubbtImiddot On the bnsis of the amounts determimd the results in this runge for the plmiddotts(nt lIlcthod ayernge apploxinHltely j percent highcr
~LAIII~ 7-(oIllJl(i~on of lltlllrIic (IIri mOtllinl SJl(II(r-(ulri-wall IIIrtlwrl~ of rlrrlIIillillfl 11)1)(1 COIIrll of UI(III
1 Flowers frllm amiddotmonth-oltl nursery plants
YAIIIATJO- OF SIli(LE DETEnt1NATIONS Fnoll TnEIIllIEAN
Rllbbel (Uall8i8-Thc plcCision of thc pLcsent method when gunyule tissues Hr( nnnlyz((1 for rubber may be j udg(d flom I Ill datil presentcd in table H TIl(se dahl -how that thl pplCPlltag( uriation of single determinatiom from nwan yullles with low standllrd enolS ranges from less than 1 to 4 p(gtrlent
R(8in~ wWlsi-r-s lndi(a((1 011 page ~j he INntlts s((uled hy the present phoolllttric nsins llHt hod are not tliltly (olllpalable with those of the grtLVimetri( ncetol1l-cxtlt1(tioll II1etho(l Thjs made it necesSllry to selc(t another lalibllltion staudud-tlll Ipsinous exullate from gullyule shrub-thut gies relatively COllstlllt photometric readshyings (table 5) The resin (olltents of guayule roots branchcs or leavcs usually ran(~e from about) to 1-1middot pelcellt The ple(ision of the present methotf WhCll gUHyule thslllS lIe analyzed for reins may be judged from the datalHmiddotpscllted ill table 9 1h(se data show that the p(lcelltage variatiun of sillgle lhmiddott(Lminntions iLO11 meun ynlnes with low standard NTOrs rangcs from about 05 to 4 percent
bull
bull
bull
bull
bull
RAPID PHOTOMETHIC DElEruIINAlION OJ RUBBEH AND HESINS 35
IAIILE 8-luriation inclieute rubller (mallSM of [1wIIle tissue bll thc 1111O0Illclc metwII
Vnrlntlon~Ilbher I (rom mean
ierCtnl Percelll ~OU -22 ~ 25 +27 ~ 20 +18 ~UO -22---------1_______ 51110 0G6 bullbullbullbullbullbull _bullbull
10 ro ----=ii41075 -01 1000 +11 1010 +13
rlln HI itil 1l9~ 1_ ___ =-~~~
115511 ~ US -111 III II 1575 -13 115 b tiS -I a 111 h WlU +22IIM-(middot bull 11K -1Ja Illi c 1000 +03 1J5H1 W +l)7 ll1imiddot tl 1575 -13
Mcnn 15951 131
1102-11 21fJ() +21l102-h _ ~~)SO -17 1102-c bullbull 21CO +21n02middotd ~OIiO -26
2 r~plusmn Il~ 21151 261 I -~-------bull---__ _~~_~______l-___--_
1 lhe$ 1111($ I1n (or SlIlIIllltS Stpnnltplr PHrilClld IIrtlrdlng 10 1hr prollIlIlr( OIiIIiIl(o(I on Imgt$ 4 to IC ~tcond nUlI1 hlr r(J)[ltnts stl1ndnnl llrrot of tilt 1I1(1111
1_1l1~ n-J(lri(iot in relli(Upound rpoundsins (lllalIsfs of VIOJII( lixsue b1 the lhomillric lII(lloli
-- ---~--- - __-------- shybull I I I I Varlgttton
_________~___ ~~lu_n_Jl_Q_~~~_____ ______I__~_o~S_J frOID lDean
Percent Percentgt458-1 ~65 +41IWtl-li 130 -a2Hli8c aliO +26S41i8-d bull 130 -32
1(-011 34I10Olifgt __ bullbull __ ~--====
li-9~2n 881) -06 li-9~2-b Si5 o ~HH2middot(middot S i5 -6$-H2middotd 000 +1
8851 054
O i5 +6 9 i5 +6 950 -20 U75 +6
H-liG3o-n bull -1 n-li6~b bull __ _ -IH-IWH +4H-l61511 bull -1
1tmiddottlU
62~-lI __ 62~-b ij24-( bull OH-Ji
(-Ull
I rll(St oluls nre tor separately ~xlrflCled SllllllllCS IlctOrdlug lO procedure outllned ou pages 4 to 10 i Secoud number r~prtgeulS stulldMd error of lIe menn
36 TECHNICAL BULLETIN 920 t ~ DEPT OF A(]RICCLTCRE
ReUUER A~ALYSrS I~ CRCOE-RcuUER PROOCCTS
Sew rapid photometric m(lthod~fol the ddellllinttion of rubber and reii Hi ill uaYllp ti--ut htp lllell pIPHnl pd oil pag( ~l to In A brief H1111111tlY of It similar rnpid llHthod fm 1I1hb~rllnltlysis of u1lulcanizNl tlIldp lubbll pl(Hlmtlt whielt i~ bn-(tldo on the prill o
ciples dehtilcd tlllLe follows Duplltate nt-gm sllmph of the finely cliyiliNl IlInttlitiup wlirllll out [~ei-()l (all hl lIf((tinmiddotjv INd to lt1iyidl till alllpl) TIll kltolll-olubll portion of till )111(11( tlrc di-olved a- indh-Htpd fot thmiddot lllnkill~ of -tlllHlunlluhhll olutiou Oil Pt 1II hut tIl IUlIp Hn lIn l-fplImiddotd 10 lHI-ml rolllllltti( fln-k antil1ltld(lup to Olllll1l The bnlulUp or till JllO(ldllll i- thatutlilllll on paWs -1- 1 IHI Ii 111( 1(111 1- nIP IXPIP--pd nil til IHi or Iw oligiJla w(lullt of I Ill (I11l1p-I1l11Ilt1 1)(0(11(1
Hupitl PlllimiPJojgtiWllllllllh llIltllOd~ fOJ Ihl llPtlmiddotminntion of ImiddotUlJbll tlnd 1(-illo- ill -111111 Illllph of gutlYllll tiUl IIll dl-eli)ed 111() IlltlY d~o Ill nltlI1lld fOl III Iwl Illhlwl- and l~iJlmiddotb(lLiJlg plant TIllt l[Olllhup hns nlo b(l1l ntuptpl fot IIH lltlIll1illtltioll of lllhbpl ill 11lHhrublwl Pl(Jdlld~ HIIl 1111 hI ndaptld JoJ IIll ann lysis of ynt1J(gt( ic lllbbl[- The llllthmb HIP 1gtn(11 fill tIll fol1owill plimiph- III Grinding
tIll PIOPlly driPl t i~lIl 01 Ul tillg tIll pnHhHt to tll l((lllilllllh~lel of filWlH-- til plllllit qIHlIllilnth( lXIIHtioll 01 IIlbhlI 01 1(--IJl- () llsing oXWllutld olnuh (kttoJls IIt(talp and() fllltil for LIbbel and IH(ltIlIlyptIJllIllIoolYlnJld-o flJllh 101 niJlsl with t(lathelr high IlPililig points 111 to n C) l]olle or in mixt tIll thllt Pll mit tlll rnphllxututioll of luhll(l OJ [middot(ill ill ~() to (l mi1lutp It r(latiwly high 1lllIllllltlltP Ill to 1~11 ) l) lllllipitntillu till luhblI OL Imiddot(ill frolll aliquot () f till oltn ion I IlIlllI-i () f Hlltabhmiddot pl(~(i]litallt (willifhmiddotd lthmwl fOl IIlhlHI Hild llitlifild lllr fOJ JP-illl t~) IIlHkillphotollllliilPIIIIiIlof PlllPlltal of liht tLaIlS mittUl(P lIftlI IlIlbll (II Il in PIlipitalioll 11 II WI( Iplllh thnt (limiJlall till PIIOl dill 10 xtralllOlh (0101 (till dptl1minntinll Iph jill 011 tIll dtwlopllIlJIl of H HIli rOI1ll tlllbidity 111 hpl than I (olot rI
jJlIlpOP-ofallnlyi-I ( p(lllil1thb IIllijOI1ll turbidity or 1llt[lIinmiddotd d(ltl of jgtIp(ii(JlI l)~ lIltlkillU tIl plllltollllmiddottri( ntdillU al tandinu tiJlH~ (dlllilll wlli(h IhlllH(lill-- IP 1llutinmiddotly tnhll) t1ll1t an hlsl~1 oil the (oJlItlIlllItion of IIlhlHI Ill I(ill (lIPIipitat((L
TIll -I(p ill till jll()(Plhul HIP 1-- follOylt (1) 1l~UIIL uJ1lplls of thwl UJfJlllHl (II tliddl(l HUt dlipd 11Illtplial an lXIllltel with11 Ill of till nlnll ill t (oU tlllltIPlll[gtPImiddotatlup oil Iath at 11 Cbull fol 11 minutl I) iIP1lIin(middot(lohd til( (XUtllhllll Jltldl lip to It middotml ynlmlll til( (nlifild by (Illlifllgiuu HlId thlPl IlI nliql1ot of tIl (IalioPlllxUlltl nll Uillltlmiddotll(t to l-llll OIlIIlIllril fiuk- (1) For a trial Ilnditlg 0111 III tlll j liJmiddot~t IllHII IIjI to Ohlllll with lilt Pll shy(ilitnnl a 1(11 it 111 (Dod fill llli lIut ( ptotoJIIltlil IPtlllillg-- of pllllntnl or liuht tlUtllIlillal(I oil n (lpel OphotnJlllllI at rase hng-tlt (If 11 llJ Ill Ol It lollllil1lPtImiddott lloyidld with tIll P10]11 I 1110110shy
Ihlolllltt hmiddot Ii1llI Olllhi lIatioll for -1IpItillg UJlproXilll1l tply Wtl P ]Plwth )0 mp are HHlltk TIll Illldillg lliJtaillld fol tIlt 4-milutl tliall(~ll-
bull
bull
bull
RAPID PHOTO~IETRIC DETERIINATIOX OF R(BBER AXD RESINS 37
ing are referred to a table of equhmiddottllut~ previously p1(pa1elt1 on the
bull basis of 4-minute reac1inJ~ for tilE nmge of lot1telltlatiol1- of rubber or resins to bE elHOlll1t(led tmd gidn thtmiddot -tnnlillfr tillIP fill rUbbEt or resins aiter prE(ipitlltiol1 lwfolE photoIllNliI j(tltlill1 un IUade The r(middotnmining dllplllatt aliquot lll then HHllil up te ol1l1Jle and lpoundadillg ale marle ut the -tandillfr tiUlE iudklltll ill rhl tall1lmiddot for the final r(adillg~ -1) 111( milli1lnm or p(tCPlltllt- of lllhbpL (II 1(-in pr(s(nt are rpadholU a prlpan(l table of lquiltlput for tlll photoshymetric readings h1~l(l ill pnell e1-E on pxpPlilmlItal lhln 1111(1 u-ing as stimtlltlds pure luhbll in 1l1bbtl milllYb aIHI guaYllh ll-ill- lxIHlatt~ in resins detNIl1111lttion I
LlTERATlRE CLTED
(1) lUnSbull 1fl36 THE mURMIXTIOS IIF IOTA RE I III OOl THER llT~II
F1 bullrol IlY U(T1l0fll UfSlfi ~rrnrl r flm lt1 KEYS TI Bill Chern 114 44J-l59 illns
t1 ~ICPHHlObullbull T 1J3bull~ lUTHOO roa THE PtRInCAnu Or a(lIUl IRrIlHU It of TIn
PLRIHEU Htllllflt [ i Bill lallllall 111 Rmiddot 711middotj iIlus
I ) RHBERG P B Ul5 A METHIlO Or ~u(ronrll-nl Hi tIII rUIl[1 f71 ii illlI
bull 14 Hoss W flbull and HARDESTY J O
llH IR1ltDII Of HfITilIZfmiddotR DllIJS ltt 1 Yl fll Off gI bern JIIIlI i ~middotmiddotlf IIl
101 SPEltCE D nnd CuoWELr ~I L 1933 DETER~n-ATIOo OF RtBBER Ii nrllllpoundRBfR Iusr 1uI II1 amI
Em~ifl cttIliIa~~ r Ell i 71middot7i l11 (HI WALTER E D
1U44 ISO~nlS OF PRTlltSrr 1trHpoundV bull l UI n W lHHt (Tnmiddot 1ETS FROM GiYI l~iIl lItr Clttrn SII J UI titJ middotn9--C1 ilIu
17 J YOEbullbullr H lO~( roLORIlETRT 771 IPmiddot nl -W Yurk f H Plrwptric hmica
naly-II rimttry lUll XphHHlnmiddot~ y 1 1
11
HI) ~ fPHELolzTRf 57 111bull Lin xw Yk t H lt PhmeHt CblUlmiddot ila AnaiY~l~-(H lithrry and XIhmiddotILpfIY Y wirh enomiddot rrJlllrjr hy H KtlJnJU11 I
t~1I --- and ~ARVER L 1f41 nlua-w ~in L liLhr IS IP ll~ XIW Yrk
bull For-sale by th~ ~a~fr1nt~nf1ent Dt~c~~ogtnts-~ s t1i rArnn~ut Pn~~~ tJffieshy
Washington 5 D C bull Pl lU ~nts
Glns pound1111])(1 ) jlllll in ((iamptl for 1( ill tltlm~rprljlJg- pighpll fllJlplpS HIIl1
bull (lnrin(d IXIIat to -llil ohllnlllI f1aI~
i(p-mollllt gingt hntl will llntit OJ 11I(lal J(IP (n] fOI toling- gIollIH plallt samp(
Halmiddotk for hllldhlg ill-llll middotPIlIlilnp nlHs IIIH ~i-1I11 YOlIll1pllit flll (Jig- 31 Alltolllnti 10(1-1111 ~middotI(lX IlIllPUp of IhI fq)p llsltd fOl Iitis with intpl(middothallg(middot
nh1t H(JlIlHI joint 101 rl1phl lPfIPIIIlg (lj 1lIhhpl fllld 1(ill lll((jpiltlllls
bull
FllilHE Had Iqllind fool IIJI(lill I 11 (111111111laquo llllmiddot alHl (I) limJ VfIlIlllllJi( tlak~
bull TIll itl1jHlIlWI of n Illb tlpl of d(Hdill(~~ III [gtJ(Jtnllllllil lllll~
i dblmiddotwmiddotpt hy Y (J( I _ j J i) t Illt riflllmiddot t tth~ n n Ii 11 111 h111 I t1loOIlldy witl nap lllltlIHI 1111 1l1id bpll tlll- HII lill(ll with (jtt11lill olutioll Hlld ltll If fla k It It [lllijljtnlld 111bhll nl
11ill lIll til ~tlllld all 111th Ill lillI Illmiddotforl 111l In 1(11 it j~ luhmiddotjlIll] 10 1111 0111 ilH (111(11 11[ Jpli~ Ii tllp wall TIll
10 TECHNICAL BULLETIN 920 U S DEPT OF AGRICULlURE
25- and 100-m1 volumetric flasks arc rinsed two or thrce times with tap water and then with cleaning solution al1tl watel as is customtny In all cases the rinsed glassware is dried in an inv(ltell position at 100111 temperattlre 01 upright in a drying oven The flasks used IoJ extracshytion of rubber Iron1 kok-sagh)z (Talllrl(((IM1 kO-8aghyz Rodin) are finally rinsed wHh the solvent to be used and are nllmnd to lt1Inin and dry under a ventilated hood Cuwttes 01 absOlption test tubes nre handled and cleaned aH directed by the manufacturC)s of the llhotoshymetric instruments used
RUBBER (CAOUTCHOUC) CALIBRATION CURVES
GENERAL CONSIDEHATIONS
The lubbeL hyclroc~rbon stau(ild is pllpa 1((1 by extracting the rubber from guayule bssue ac(ordll1g to tilt SPCI1((-Caldw(llmethocl (5) 01 by the Holll1lH-HaasiH modification of this method (p 2) The air-dry extraeted ltlbber is dried furtlllr in It vacuum OYCl1 with 30 inches of yaCH1Il11 at 63 0 C for 4 hOlIlH Till rubhlI sbindanl is preshyserved h1 It clos(cl contaim1 sto1(d in It r(fligellltol BCfole th( samples nrc weighe(l out the unopened cOIlbdn(l with the rubber i~ brought again to room tllllpelutnre
Two stock solutions each in triplicate from separately extractml standard rubber satnples nre prepared-the first sct of (-111(( containshying 01 percent 01 1 mg of luhbC1 ])(1 lniHilit(l and the other 02 pershycent 012 mg of rubber pel miJlilit(l TIl( (I(~il(d w(ight of rubb(L contiiinec1 in It known VOlIl11e of th(~ solycntis withdrawn Irom Il
burette or pipetted and made up to 25 m1 the standard volume used throughout the procedu]e
The rubbcr samples (01 and 02 gn1) for the stock solutions are weiOhecl out to an aCClllal) of o~ mg on nn analyti(~al balance The rubber is best mnnipulated by mNlI1S of t1l( stJai~ht hlunt-edged top of It cork knife With a little prnctie( OIl( (an leltlily sepnrate t)w desired portions by pLeSSIl1C from aboye Further subdivision Is mndt on a stout PVllX at(h glnssnt lla~t 2 mill in thlkne~s By pressun f10111 above and sheuling aetlOl1 Ye1~ small pnrbcllH can be separntetl so that the requit((1 11l110unts (un 1)( w(igh((l Ollt accurately The rubber sample is then divided into sl11a11 piC(es on the special watch glass by meanH 01 II coll Imife
One mil1ilit(gtl of lt1i isobutyl ketone 13 js placed in It special 30-m1 trituration beaker (fig ~B) and the fine1y diyilt1ec1lubber sample (01 or 02 gll1) is udd(d and heated on a hot plate under n ventilated hood to Il tempelature jllst under th( boilin~ point of the olvent A special glass rod il used t () t rit II ate the sumple (fig 2 11)
When the rubl)(r hll d issohed so as to makl a hOll1og(J1lOUS geUike 111I1SS hot methyl isohutyl ketone or an oI the other luhb(L solvents recommended (t aIJI( 1) is add(d and niicd with the rubber soltItion
31 Diisoblltyl ketoul WIlS not aailab1p (Juring ValtimC l1Cthyl isolJutylletonC 1II1ly be substitnClt1 11111 it is not a~ Cf1kiCni In Illis olllntion If the IllttC1 is used It is b(SI to pl Ilw fimlr diillPll Iubhpl palll(s slan( oPIuight in Ih( solvCnt lind 10 (OPl til (onlalll1 to IllinilllizC elIpornt(111 of sohPIII bpfolp wa( Is nppliecl to completp nlutioll
bull
bull
bull
bull
bull
bull
RAPID PHOTOMElRIC DElERMINAlIOX OF RUBBER AND RESINS 11
The mixture is tllll1sterled to It 100-ml yolumetlic flask with sevtlul washings of hot solvent cooled to n s(uHluld telllpelatUle and madtmiddot up to volume with the saIne solwlli SlwtiaJ IHl(uutioll mllst be takell in transferring t)( lubbCl solutioll to till YolulIHtrie flask so thnt llO rubber is lost It is cOllytllielit to illSllt It j-ill(h funnel in the ne(k of th(~ voiumptic flask to pOll tll( lubb(ll solut ion ill OIl( OLWlHtion into the tube of tht IUlll1ll with Ihl aid of tIl( glllss Iod nlld 10 follow illlshyl1eilintely with S(gtllnl ~Ynshings of hot S() I(111 whkh lIl lilst pouled 1nto tIll btll PI 1I(ld dIIleUy OW) till 1unn1 aId IhpII t1I1uugh Ill( funnel
H time hi not all objllt it is uls() flasible 10 p1alt Ihp linely diided particles of Iubblt ill tl( flask toJ1tuining Ihl sohPIlI 11(1 allo it 10 stand until til( 1lIbbpI is dissolYld TIl( llIblJll ioluliol)s alp slolpd in Ihe tightly s(ojlP(1(d OIUllwt lit f1nks in a ((lol dark placl Thel they willltIIlUlIl (OlUilallt ill Idut 101 an indlfinit( JlPIiod
Two ellliblHliol1 (IlP~ flIP IIltl(l(-OIl( 101 o~ gill of tisHlIP (ollin illshyhw 0] to 10 PII((Il of rubb(I ((1lt)middot1 to U mg of IlIbb(Iill tt ~)-1Il1 yo1ullll) and th(middot otlHl for ()~ gil) of tisslIp (ollaining 10 10 ~l() peLshycent of lublJPl (O to 10 Illg of lulllJpI ill a ~)-))Jl YOIlII1IP)
(Hns HlJ 111 TO 1 II~IWEX( (II BIIII1EH
III oldl) to ll(llllP (ITOI (0 II Iltinil1lIl1l a lIitahl( lllillobllllltp is lIs((lo Jl((lpn (P IhI ~lt of stal1da Id solut iOlls 0 f a Ii ng (OJllllllllll ious ill til(gt (III)(r( Ol 10 1 gt(I((lIt of LubbI In (11( PI(sPIII WOlk th( 1111shypIoypd HlhlHIg mic)obm(ltp Il bullJ) whkh lIi(IlJalpl dlli(I~ 10 0001 1111 was Toulld sntisiadOlY F(OIll n lll-pltIllllt -talHlulIlllbwl solushytion in HSlIitnbh solnnl lt[lIiIlIUJl1iiat( aliqll()l~or n) Ol o~ n and ()t 1111 al(lllla~UIpd (Jilt ut n stalldUld ~Olllli(lll tlIlIJl(1atulp (~) C ill wlitllmiddots labolulol) I IlIIHIl-of II lllillOillIl(tlt illio ~l-lld yohulI(lie f1nks ploid(d it h gla -(OPIllIS gllollgh of 11ll lubhpl sol Pili i~ thllI addltl to (tl(lt flask to IlIak(1 l 1111 Ill1I IUI(middotc (0 t hl all)ollllt of lllbOPI solutioll ]ll(yiously nd(lpdbullflll DI ntl 01 JlImiddototlmiddottli lolloid solu tillil Iras h(PIl Hddld lIP (bhpl is JlI((i pi III tpd IIlld SP(middot(t )opl)()tolllshyd(gt( 01 (jIOlilllltp) IPallil) an IllHdp 1I((OIdillg to 11ll JlI()(pduJ( Oil shylitwd Oil pagp 1middot1 Th( 1(ldillg~ 101 palmiddotll (OI1((III)Hlioll alp 1I(Iaglt1 anel plotttd Hgaillsl t( ntilligllIlll of 11))1 hI n ~)-1ll1 (jIIlIlH 0) [gt(lClntagl of nlbblI (nltuln(pt 011 tw bnis of tl2-glll lilsul Slllllp1(gts and aliqilOt olulllt IH(IOI 101 (itl ]1I(J((dlll( out lilll(1 Oil pagl 1middot1 This PI()((lhll( i ((l(alld t win ill (a(1 (11( II slandald llIbbllsolushytion was PI(gtllllpd IIOIlI slpa latll XllH(1 ld 1 a utln)(l lllbblI 1 III pips TlwcOlllpl(tpdtlla alp pol(l (1) (loldilla pap(laslrowl1 ill figulp I
Tbl )llO(p(II I ill lllilking a (Uln rOl I to ~ jiI((lIt of JlIlJh(1 i~ simi1t1I to (hat rOl 1Ill l1IlP ImI1 to 1 JllI(PIII (x((pl ill a f(middot dptnils The quinlu]lli(Htl aliqllols a 1( sput(d Ht (lI 12 a j 0 (78 n alld 10 mg ])(gt1 ~i-1Il1 Yolunl III sNuIing thp 01 Illg pll 2)-Jll1 YUlll))lt til( (gtIO(ltlIII( outlillPcl ill IIIl PIp(tding pnltlgllIph is followpd In the rllngl 1 toj Illg )IN ~)-1I11 OtIIl1I Ilw (lsi 1(lt1 (oJ)(tlllltlliollS of lubbpI alP s(gt(ul(gt(l h IlIPHsuljng alhplOi- with Xnlional BIII(atl of Stnndlld~ tltllsf(I pip(Ws flOIl) tltl OI-PlIl(1l1 lII))ll sol III ion
12 TECHNICAL BULLETIN 920 U S DEP1 OIr AGRICULTUHE
RUBBER IN 25-ML VOLUME(MGl
100 1~__middotOT5___ITO___15__2~O=--_bull 2r5_---= bull 3rO__~-_40 bull99
98 shy(I) CI Z
~ 97 ItJ II
~ 96a f-IIJ
e95 o l
94
93
92 ~__~__~__~____L-__~__-L__~L-__~__-L__~
o 1 2 3 4 5 6 7 8 9 10 RUBBER (PERCENT) bull
FIGURE 4-Cnllbrntioll curve for rubber in 02 gill of gt1n~ule tissue containing 01 to 10 p(rcpnt 0 lllbhlI (nlnllillg~ (Ill 1111 J~pl~ll llhooplf(middotttmiddotlc colorimeter with 720middotmu filter und amiddotml uperture the 01 divisions required in actual pracmiddot tice for photometric IclHlings arc olllittltd)
Similarly hl the range 5 to JO mg pel 25-ml Yolume the desired conshycentrations of rnbber urc measured from the O2-pllmiddotcellt solution The complete data lire plotted on semilogtllmiddotithmic pttpel as shown in figure 5 A
STANDARDlZATJON AGAINSL G1IA111 ETlIIU 11 ETHO()
1he alternate ploee(lule of stt121l1ald izing th~ IneHell~ method ngninst the Spellcc-Cald well method (II) altholl~h flaSI hIe 18 not adVIsable because of the extra work J(quiled ancl the introduction of the expershyimental error of the benzene extraction method
HESINS CALlBllATION CUIlVES
The procedure for constructing cal])lation eUlves for resins ttIlulysis is similar to thtni outlinlltl for lubb(l lxcept that resins exndate of gunyule is lIsed as the resins stundard The resinolls exudate disshysolves very readily in the resins solvents listed in table 1 It may be prepared in two ways for use as a stnndard-the clean exudate as bull gathcrcd from the plants is dried for 6110mB nt 65deg C nt a 30-inch ltcuum or the oXllllate is dissolved ill acetone and filtered In drying
bull
bull
bull
RAPID PHOfOMElRIC DJllImlMINAlION OF RUB BEn AND HESINS 13
RUBBER IN 25-MLVOLUME(MG) 2 3 4 5 6 7 8 9 10
r~
eo en ()
90
f--70z Q ~ 60ltl LIJ a ~ a LIJ 40 E 0
0 50
~ 0 ~ I 30 0 ~
A 20 I I
o 25 50 75 100 125 150 175 200 225 250 RU88ER(PERCENT)
RESINS IN 25-MLVOLLIME (MG) 2 3 4 5 6 7 8 9 10
1--90
80
en () 70
I z Q 60ltl LIJ a
50 0
a ~ LIJ 40 E 0 0 ~ I 30 0
B ~I20 o 25 50 75 100 125 150 175 200 225 250
RESINS (PERCENT)
lJIGunE u-Cnlibrutioll cUve for (il) rubhcr in 02 gill of gllnn11c tisme conshytainingl to 2G perc(lt of 11IUU(Il I1na (1]) rpSillS in 02 gill of glI1~l1ll~ tissue (ontnining l to 20 nelecnt oC l(sin8 (U(ndings Oil 1111 E(lI~1I llhotollectlit colorlmeter with 720-mtL filtcr and O-ntJ aperture the lO divisions llquired In uctnul prllctlce for pitotoulPtlie PllllillgS tlre omitted)
in vncuo arelntivply HllHlll qUllntity of (xutlnte is plllcel] in a lalge dish since the mass rOHmS nt the beginning of the drying process Pracshytically ull of the ne(tone is evnpollltpd olf oyer a steam Ol WItter bath and the residue is dli((l pnlYllized in It mortnr and preserved by
14 lECHNLCAL BULLErrN H20 U S DEPl OF AGRICULTURE
drying as indicated for fresh exudate In all ClSeS the products are stored in airtight containers in a dark coul place
The usualllnge of resins from gunyule tissue is about 2 to S percent on a dry-weight basis For work with this plaut therefore on1~ one curve is needed A typiCallesins ealibrntion CUlTe is shown in figure 5B
PnocEDuuE J~OH RUBBER ANALYSIS
Duplicate lXiLllCtiOllS arc made for each tissue analyzed and duplishycate photometric readings are made for each cxtmctioll the final value therefore reportcdreprescnt- nn avcragc based on the four phoshytometric readings
Thoroughly mixed O2-gm samples of the finely ground tissue are weighcd for analysis on the basis of l11oistUlc-frec tissllc The samples arc weighed to an accuracy of 02 mg Oil an analytical balance The method of deriying factors for making eOllections for moisture in samples has been thtailed on page
The weighed samples arc trallsien(c1 to the 2-m1 volumetlic flasks with the aid of l-inch glass funnels and 20 m1 of methyl isobutyl ketone is added to each flask The contents in the Hasks are heated m a constant-temperature oil bath at 115 0 C for 30 minutes uncleI a yentilated hood rhe flasks are removed and any adhering oil on the outside is wiped off with Kleenex 01 H similal cellulose tissue the C011shytents of the flasks am cooled to a standard tempellltule (25 0 in the writers laboratory) in a constant-tempelutllre ater bath provided with a motor stirrer if available and made up to volume with the solvent After the contents are mixed the flasks are allowed to stand for a few minutes until most of the insoluble residue settlcs to the botshytom The extracts are then carefully poured into JO-m1 heavy-duty centrifuge ulJls so as to include as little as possible of the settled insolushyble residue The centrifuge tubes are stoppered with cork stoppers and the liquid is clalifiecl by centrifuging for 10 minutes at 2000 revoshylutions pCI minute The clarified lIquid is poured into 25-m1 volushyl1Ietric flasks plOicled with ground stoppers It i impoJtant to pour off the clalificd (dlart in lWIt a lUlllie that the ill8ol11ble cNi(hwis not Sti1((Z1tp A 1-in(h funllel is plncCd in the neck of the volumetric flask A filter stick (fig 2 D) is inserted in the centrifuge tube through he liquid so that tlH enlnlged palt of the gtiek seals off the insoluble residue and a small portion of the exmet in the cone point 1Vith the index finger the stem of the filtel stick is thell held against the side of the tube towllnl the analyst who holds the tube with the thulllb rmtl t11illt1 fingCl The txtlHct is thell poured off easily into the yohunetlic flask without distnrbing the insoluble residne The COllshytents of the Hasks are then ))ollght to the standard tel11pelatme in the constant-tempentl111e wnter hath
The reagent blank us(d wit h the spectropllOtoll1lter 01 (olorimeter ig prepared as follogtvs ) 1111 of methyl isobutyl ketone 01 other solvent used is pipetted into It 25-m1 yolumetric fiask and 01 ml of protective colloid solution for rubber is added the mixtule is made IIp to olume with acidified Oil-pelcent ethnnol and mixed again the rcquired vo]shylime of the mixture is poured into a cuy(tte or an absorption test tube
From each plir of tissue extractions to 5-1lll aliquots 01 the clarishyfied extlact at the stnndanl tempCraLule ale pipcUed into 2ii-m1 volushy
bull
bull
bull
bull
bull
bull
RAPID P1IOTOMElRIC DETERMINATION Ol~ RUBBEH AND RESINS 15
metric flasks and 01 m1 of protective colloid solution for rubber is added to each One additional5-mL aliquot from each pair of extracshytions is similarly prepared to serve as a key to the standing times for the final readings as indicated in table 2 These additional aliquots are first made up to volume with the precipitant acidified Do-percent ethanol mixed by carefully inverting the flask three or four times] and allowed to stand for 4-minute periods before the reading is made on the colorimeter Vith these preliminary rendings a~ a basis the standing times for final readings are taken from table 2 For example if the colorimeter reading in rubber analysis at 4 minutes is 655 then the standing time is 15 minutes
The two rell1Lining duplicate aliquots for eath extraction are then made up to volume with acidified D5-percent ethanol mixed by careshyfuIly inverting the flask three or four times nnd allowed to stand for the required number of minutes as established by the preliminary 4-minute trial readings (table 2) before the final colorimeter readings are made on the contents of the flasks
TADLE 2-St(llllliIlU time for variolls (OllccntratioIlS Of rubbcr or rcsins aftcl iJleaipitation bcforc colorimetric readings mc macle
[5middotml aliquots of rubber in methyl isobutyl ketone or of rcsill~ in ncetonylncetonemiddotcellosol e 3middoti both made up to a 25middotml volume with pr~cipitantj readings on lvolyn photoGlectric colorimeter with i20middotml (690to iiOmiddotD11) filter and Umiddotml aperture]
RUDDER I
Range of colorimeter Approxima(e S~nuling i Rnnge of colorimeter Approximn(e Standingtrial readings after 4middot range in conmiddot tJIIIG for trini r(adings nfter 4 range in con tifillnlOalcor minute stunding time tcnt In tiSSU(l Unnl I t I t (rending IIlIDU C stum Illg lOW _ tent III Issue reading
Percent Villlits II Perfe~lt Jfinul 955-999 bullbullbull bullbullbullbull 09-01 00 01-03S bullbull ~ _bullbullbullbull_ Jl-O9 10 743-954 bullbullbull ~ bullbullbullbull __ _ 43-10 30 1420-550 bull ~ ~ 137-94 5 6_3_9-_74_2__bullbull_ bullbull bullbullbullbullbullbullbull_-_---- 6__8-_4_4---___ bull ~ ~ bullbull ____ MQrcthan 13ibullbull_-~_ _ ____ 15_~elow t~ 2
RESINS -----------------------------~--------
957-999bullbullbullbull ~ 139-01 60 11419-amp11bullbullbull _bullbullbullbullbull ~~ 13~5-939 10729-956bullbullbullbullbull_ Ii 25-1 middotJO 30 ~gtl2-40(L bullbullbullbullbullbullbullbullbullbullbullbullbull _ 2025-1320 5 595-728~~~ bullbullbullbull 8 as-G 20 20 IBelow 292 bullbullbullbullbullbullbullbull- More thun542-591 _bull ~ bullbullbull_bullbull_bullbullbull 038-039 15 2025 3
I Precipitated with O5middotplrccnt HSO in 05middotpercent ethanol When the npproxilllull concentrntion of rubber or rcsins in solution is not known trinl colorimeter rend
ings atmiddotJ minutes s(nnding till nrc mndelS n guide to the required finnl standing time indicated in the last column III prncticc UII cxtrn nliquot is prcpnred for precipitation and thIs is discarded after the trial reading is mnde
3 lrccipitnicd with OmiddotpcrccntlhSO ill HO
PnOCEDunE I-On UESIliS ANALYSIS
The procedure fol resins unulysis is the same as that indicitted for lubber analysis eomiddot(I]lt that f he -olyent js acetonylacetone-cellosolve ~)-7 tht precipitant js O5-perctnt H~SOI in H 2 0 and 01 1111 of the protective colloid solution for nsins is added to each 25-m1 flask conshytaining the aljquot of the extract before the precipitant is added
PnOlmmlHlC INSlHu~mNTs UECoIUlENDED AND CALCl]IAlION
OF UESurlS
Photometric readings of percentage of light transmittance (T) ale made on the Coltnum double monochromator spectrophotometer at
16 lECHNICAL BULLElIN 920) U S DEPT OF AGHICULlUHE
750-111 wave length or renclings n1( mnde on a colorimeter pLoic1eri with the monochromatic filter eOIl)Il1l1tioJl for sllecting the npploxishymate wfLYe ]cngth at 750 1Il~ For routine deterlllinations the Evelyn photoelectric colorinwt(r ployided with aTW-lllJ filteL is IC(0l1111HIHtll
The liquid in hich the preeipitnted lubber uld rcins are susshypended is pOll(d very cHrdully down the ill~idl of th( clette o absorption tube to lLYoilllllC fOLll1ntioll of ail bllbblls Aft( LUbbet find resins preeipitation wlwn the EnLynpho(otkcllie (olo1imetll is used the readings are nmde nft(L thl standing tillll- hOWll in table~ It has been foulld (OIlllliellt to 11lPtipilatl tublwr 01 llsiIlS from the aliquo(s at ~-millute illtlLvals This allows stlilieipnt tillle to check the eOlolimet(r and to makc 111( lNHlings Vlwll a ehangp is IlltHk fLom onc rending 10 the l1lxt it is advisablp 10 llle the clIvctte 01 absorption tube nt lpast twkp with slllall p(Iltion- of the llllltiol to be leitd
After the colorimd(L lluding lta e becll Iltndp till IlIl II igllIlllS of lubbel or resins or thc lpL(el1hlges pnslnt in Ihe aliqllot are r(u1 from cal ibmti(Hl (urVlS (fig~ 4 and raquo or from plepn Led tables of eqllivallBts baecl ill each (liSP on (x[lerimPlltnl data The results are expressed as percentages of dry weight (S hours drying nt 100deg 0) of the original tissue The errol lltle to lCflyjng the insoluble residtH in tbe voltlllletLie pxtLHclioll flflsk wlwn the pxtrnetis being mnde up to YOlllmC is V(ly slight sinlte only (U gm of tissue is used FOLroutine allalyscs lhis ery slight eLlor mny be dislpgnltec1
EXPERIMENTAL RESULTS
The experilllCnlal reslllts Oil hi(lthp method- of tU)lPI and l(sins analysis a le based ttl( d icussld blicfly hlrehl
PHEPMINrlON OF SAlULES
No difliclllty was expPtitI1(ed in pltparing slmplls of llllrscly-glOrt guayule plants 1pss thnn ~ YPH1S old 101 rllbbpl alld IPSills analysis In the cnl of Odll filld-gl()n gllayull plants PIIOtS hopel mtty be introdmp(l by the custOlllalY Jlwrhod 01 pICpalillg Ihp sampl(s 101
HlutlYHis as is lwipfly i n( ita ttd ill th is s((tion Smh enOlS do llot nffCct the ])lCcisioll O[ t1H llwt hotls for LllbbtL n nd Il~in~ nnn I sis i nee till) are due solely to tIl( tbsup--ampling (llo(pdule in thi (a~e of oldeL field-grown plall TIll 1lllt1lOcl of salllplill7 fipld-gl()l1 plants JllOLC than ~ Y(HrS old thenfort Ieqlliles iurtlHl jnttigntioll
lgtAHnOILr~G FOR HEllOVAL OF UUVLgtS
Parboiling which (onisls in boiling gllltyule plants in water [OJ
8 to 1~ ~ninll(s ~s col1llllonl) uSNl a~ n llHans of Itlli rCnl()y~l prior to drymg nnd gllnllng It I~ tHI([())P ll(e~Sllr to ltItLeLnunc all possiblt~ eflct oi tlti PLOtPlllll( )ll (Il( final results Exp(liments have sh(nm that (helt i- fl Flight loss ill til tmiddotjght of lOO(S and 4(ll1S In I typi(ul lXpelillltll hlu1llHs of ~- ii) -1-ytII-old gllllll( pllllb were Italnd at randolll Olll ( of talns wa- paLllOil((1 and the le~es (1( haIHI-pi(kpd [lom till o( hpJ Ht Both pis (1( dlipd for 48 hOttlS at (i) C in a llI((lwlli(al (011((( ion Oyell Th( lpsult are SUI11111I11izNI itS follows
bull
bull
bull
bull
bull
bull
RAPID PHOTOMETRIC DETERMI~ATIO~ OF IfCBBER A~D HESI~S 17
Dry ucilht lust ill lariOilillf
Plaut (pcrcrllO 1 1 -I2 ___________________ _
213 _____bull _____ bull __ _______ ___ ____________ 12 2(
pound(111_ ______________ 1 R
4_______________ _______________ __ _____
A __ bull __ -_
The efred of parboiling on till final lllalp i SUllllllatmiddoti7(middotd ill figmc G Rubb(1 lecoYelY w(t about 1 percent higher for parigtoillltl plants and lEsills re(ovelY somewhat o-er 1 i)(lr(lllt 10Wlr The (Ii tference in lublH-l r((o-elY cannot be ae(01111tltlt1 fot by loss in dry weight _ due is to be found in a study of thE grinding lwhadol of a parboiled and an unpnrboilEcl shrub The grinding of the patboiled shlub in the hnml111 mill is much fadlitated and ns a rule for tissue with a rubber contCnt below 10 peteent llO aggregates of rubber deelop in the 1Il11ehinr during the (Jpelatioll Yitll the unpnrboilNl shrub some dillictdty may 1)( (lxppliellrl(l Sill(( sOllle of till sti(ky ltxlldutl Oil the plant may scI( u nlldei for the fmllHltioll of lublH1 ngglPgates Til is apparently explnins the npparlllt los in ruhbpl frol1l the llnpariJoiled hrllb as eompnlelt1 with thl palboilld (fig (i) TI1(loss in r(sins
II
RUBBER
10 f-
Ishyz LIJ 0 0 LIJ 0
9 --RUBBER -shy-------shy
-- RES INS -shy---shy-----_
IJ) 8 I--Z IJ)
LIJ 0
0 7 f- RES I NS -0 -shy0 LIJ III III J 6 f shy0
LEAVES REMOVED BY PAFltBOILING
5 f shy -shy - BY HAND PICKING
4 I I I 35 30 25 20
SCREENS (SIZE OF OPENINGS IN MM)
FIGlRE Ii EtIe(t IIf pnlticlp sizE Oil lEcorPQ- of rubber lind (iiil1s when lEgttiye wEre remond hr Pl1liloiling lind h~ hand pi(king ((Dlltrol) plllllt1lt groUlld in t hammer mill
6114038-46-3
18 TECHNICAL BULLETIN 920 U S DEPT OF AGRICULTURE
recowry from pUboil(d shrub may be due to the loss of the resinous exnc1ate during parboiling This exudate forms ns It SClim on top of tlw )iquol in the tank
On the basis of t1wse results the recommendation is made not to yaly the nwthoC of leaf lemoYal in any 011( lNi(lu(h project Then fltirly compalabh IcmLts should he obUiined
70 ~------------------------------------------~ LEAVES REMOVED
BY PAR80lLING ____ BY HAND PICKING
60
-I-Z 1amp1 0 50 a 1amp1 a
en 1amp1 gt1amp1
40en gt-CD Q 1amp1 Z
I shy 1amp1 30 a l shyx C)
1amp1 ~ J 20 I shy 0 I shy
10
O+--L__L-~__L-~~--~~~~~ o 10 20 40 60 80 100
NATIONAL BUREAU OF STANDARDS SIEVES (MESH)
FlGntE T-lJiMlil)utiun of l1Ultkh si~(s of gnll~II( tiSSU( JrIOllll(l in a Ball amp 1ew(1 mill to pass six dllIerNlt S(I(euroII 1(IlYes Iemoved from plants by palmiddot boiling 11(1 hand picking ((olltloll dpfo1iatld plants dried to 1I lUoistufl l0I1t~nt (If 01 to o) 1)(ICl1It ground tiSSlli IbalH1 1() minutes ill II ~i$hel
bull
bull
bull Kahn shuk(f
RAPID PROTOMETRIC DETER~UXATIOX OF RrBBER AXD RESIX-i 19
GHl~DIgtiG
bull Th~ entire pant 01 plant l)iHt a~(gt fl r(ll it pllllIIirU1ry lSillg fur J hours ntGi~ C prIOr tD t 1( plChmll1atmiddot rLlmhll III a II lItmiddot or n Ball amp Jewell mill ~n llltllysis of paldch lzP- nftl~l (oar-( IIindill shows that tlwy ar( about tIlt llllH fOl parbojlP(t awl IJllllluhoileu hrubs I fir 7)
The coalilly gloUllll ample i-- thPll Ildlll forI toUtmiddot at ni C afnr which it ha lllilobtllL(gt output of ~ llllut lII hmiddot- dptPlIIlilwltl by drying submlllpil- at 1110 fot hOtll- TIll 1 IIIIll i lltllt lmiddot0l111d hi a IluninHl mill TIll mo(lel uP(t in thi IIIk i 1I Hu IIIOilll mill as IllUllifill bv Hoss nnt Hartlet ( 1 -[1lt111- with n1ll1l1 pldushyrations ittI lilnbhell b rill HanlIolll V0ll11nHiol1 ElIillllmiddotrill (0 The size lutllihl11 iUlJnole So I ( 111m t ~ II t HUIII Xl) ~ I L~ 111m nnd So 4 lillllU1 11 ttllilhmiddotj 0 r tllP Imiddotlult~ p(lln-It willI t11(e Sll((IIiZtS with )arl)Oiltll awl uil)Jtllboiltd hrlll b lOwl1 in fif1l1fmiddot-- This hows t tnt 1middottttIl ~(I 1 llllll (Up jlllilnl IHlt that
r------~-------r--- ~ --r IHAMMER-MILL SCREEN
O~ NO1
NO2 ---shy U NO 3 ---II
I
bull lL
z
r ------ l 30 ~ gt III
i I Imiddot
i ~ I
I 1 I I
~ 20 I - 1 iii 1[ r 10 ~ ~ ~ I _ ~ I r A bullbull
o bull L-~__~__~~__- ~~ 20 40 60 80 100 40 60 80 100 200
NATIONAL BUREAU OF STANDARDS SIEVES (MESH 1
Yutln I i-tlillltiuli Hf pur id lZt f ~naY1l1 t middotnt r1 lI1 i ~ a hatlltlllI 1IIi11 to 1111 Lx IHtllllH middotIn Lt-anmiddot tIlllunl loy la1 litkh~ omrl t 1) tHul parbuih~ -t B ~ thmiddotfuliufptl ]~lahr thpt tu tt fit t 1 It+gtr-tt1 Jnui~tHn eunttlIt _~rnlitl tl~UP ltakmiddot~~ 10 UddU it~ 1 rtmiddot4~pt~middotK1~r ttakt-middot
bull So 1 gingt- 11 tt-liuin-Iy ltr~pl [lPlItl1tat of iilll 11animiddotImiddot- Eqltrimiddot tIlllll hnnmiddot llOWIl dutr fll llltldllllUU xtlutioH 11pound lnhbll lIl lP-ill frolll IolUlIl ~tlaYlllt tl-IlP by dlt IJwtmiddotlUlmiddot lItlilwd oil Ill 14 - 01
i-mllt 11111- -lwltld hi INd I li~ Ii I TIll lllhtIlttj of Itiu~ So 1 (lltll j thnt 11middotmiddot01middot lttwmiddot to amplil tltt Iollllli tilt art lpdnn ib
IntIIll ll~ i po--ihJI with tI lLllit Ilfltl[lll1t It honld l Plllplw izmiddotl rImt ilt tht h of -allllhmiddot with l lllblPl
~ontlnt of ill PPltllt til lIilll it i tlllt pll--ihl 10 11-middot t(1i Xli L
20 TECHNICAL BULLETIN 920 U S DEPT OF AGRICULlURE
Even with screcn No 2 difficult due to rnbbel tlcrltreCtlltiollS may be ob tl
encountered In thes~ caHeH it iH lWit to parboil the shlub fOL leaf lemonll and finally to dry to about 1 to ~ P(l((llt of tnoiibl1(l pound01 b(~t results jn ~rindillp in tlH hanmHl mill
It iH aclvlsable to provic1l thc hammer mill with a ground wire Hillel the presence of static electric (harges 011 tll(middot partkhH will ealls( Home of these to atlhelc to the inside of tllP (olltailWr OJ lila eallsc OI1l( of till pULticl( to form ngg1(llatls EIIolin lalllpling fl01l1 fhis SOI1I(I mlly be (onsi(h1llbl(middot
A1I10l1g the Holnllts with high boiling point that lIlay Ill IlHld in rubber anal)Hs I1IP Illllhyl n-alllyl ketolle methyl ioblltvl kptOIH diisobutyl (tOIH blltyl tHptate llethyl amyl 1Ittail (middotthyl(middotlllmiddot gly(ol diethvl (middotther and n-bntyl (middotthel (labl( 1) TIHse al( also I(sin 01shy
middotent but th( 1(~illS n1( held ill olution by the rll1)bpl pl(l(ipitant tthanol wll(1 lllbb(r is 1)J(lipitatNI (S(ll tabl(s alldmiddotl) On tIle basishyof the lxpHilllPlltH tll( btsf nil-round lolPlli -rol lS in 111( PIlHPllt method is lt1iisobutyl kPtonc wld(h was not IIltlllllfaltllllmiddotd ltIlling Vodd Yflr n A suitable Sl1lgtstit ute iH llHthyl jolllltyL htolt whi(h is l(porhd as llolltoxit UJ)
Clllos()IY(~ (ethykn( glYlol monopthyl (tIH1) blltyl earlgtitol (di(thyl(ll( gly(ol llIollobutyl (ti1(r)~ and acttonylacetOll( may be used as resins sohrCllts (table ] )
In the earlipr work with (sills analysis cpllosoly( alolle was selcmiddotet(d as a suitable solycnt Aitholllh (ell()~oh( alone is pxc(lllnt its rplllshytiwly gwatlL iscosity 1(I(b to bubbl( formation nft(I (SillS pr((ipi tatioll Thi- increased thp (xperimentnl (LTOI OIl of tltp othll I(sins solpnts tI((tollyla((tolH has the proppry of glpatly lNlulingshydH(OSity 11(11 altld(( 10 othr liquids This sohpnt tlHIeforl wa addp( to ((Uosoh( in slIflici(lJlt tlllIonnl to OPI(0111e the dinieulty On the basis (li~ex)le1inwllts ~ purts oi~ a(donyla((tOlll to I puts of (elloshysoh-f (bolll by olume) as Splldcmiddot(l Thp 01 hel Hoh(nl listed hutyl clLlbitol at l(llst the t((hnieal-g1lld( ploduct uSNl is appal(ntly not as good as eithe of t1w ot1(r two () a (ombinatioll of tlWSt
The SOlVllIts JOI liSt in tumlyzing artifkial lubbel$ hy tlw pr(senf method appllLently (lcllIHl on th(middot kind of llI))(I lIp-ityl (Jxidt is suitable Ol BUlla fi and hutyllthlI for butyllllbbl Tlwse reagents IlLe technical g1lld( Calboll amp CtllUil1t Ch(lllilai (OIP This Hllbjp(( hilS not bepn (XtpllHl(ly illwtigated by till WIit(I
PIIECIIIIJ-
All tlst fOl Ih( adlqlJalY or till IHllipitullb ll(Ollllllentillllll11Sl bl baset] on the plctisioll of tllP final I(snlts oiJtairwd with the methods The )redpittlllts s(1e((( n HpJ (xtcllsi( (xp(IimPlltatioll all HatiH~ factor (Hee fig Hi 111lt1 tabItmiddot (jH) Ext(IIin tllts llllTild Ollt hanmiddot shown that H Hatil-gtflltlOIy [gtIpeipitallt 101 1lIbblI is (li-p(IT(middotnt HzHO (c p reagent nil POll sp gl U-lmiddotJ) ill li-P(l(Put (tinmol by vohmlP liol (tllayul( Ipl-gtinl 1l)-P~ITImiddotllt H)~o ill Hl) by ollln( ii lL satishyfaeto7-y l)lp(ipitunt A solution of 1 palt of H~~o to 1 part of H~() (1-1) iI2So1 nnd abo yarious int(lIlIPdiat( proportions of tlllse suhshystanCPs giyp fait 1(511It8 but with till inlIptl(l ill [h(gt ratio of H~S01
~
bull
bull
bull
bull
bull
RAPID PHOTQlIEfRIC DETEMIlXATIOX OF HtBJER AXD RESIXS 21
to H 20 the )olutioll becollles somewhat vbcou5 and precautioll Il1Ult be taken to ttvoid bubble formation When it i5 poured into tilt Cllvettes
It should be lloted that both of these precipitants have an ftellleshymmiddottion It was found that when XHjOH was used in the rubber preshycipitant in pInt of H~~O~ the readings were -table l)Ut were not reshyproJutihk The lIl of XuOH in pInel of H 2SO j ran nHittble result as a llth H(HY(Pl WIWll til( li-P(l put lthatgtl in lublltl llnalysis or H~O illlP-ius anal)j wn-i uddint(1 thl eharalteliti(s of till liquid with pleeipitated ruhber or resiu in HI~P(ll-ioll n ren1 on the lpNmiddottroshyphotometel m tololinlPtprfollop(1 it lPgnlal lIlll II~ lxplaiHd on pHgP-I (Sl( figs 11 aIlIIl) Tid made it lloible to outain lEPJOshydlHibll tpnlt nntI (onplt1J1(Jttly till JpqnitPIl tlPgJPP of PJPcljoll
IIWIE(TI 1lt COl~101J)
Jtl thp ItJiPl middotxlwlillltnb hefoJ thtmiddot -1l]YIlIt allll pnmiddotdpitallb had lIptll ptoppJly adjutp(l it l fOllll tIuH till llP or a Ploltiw colloid -wll ltIi1)cJ [ttlJmiddotntl- imlIopl tll lmiddotpro]lIibility of the lPlllt JmUkllly ()Ilt 111 U lput lUlU illlihumiddot tOJllPOlUtl tpHd liglyeol teltlut( - llpanlItly IllmiddotlfP(] to lit til I1m t IHflll lImnnmiddott nftlr tlH filial prOIptlllll WtlP dlvPllill1 tlll 11lIlpfit (If thtmiddot [llltlltin lollohl wa Hot 0 natlv I1l(lhmiddotd III rlumiddot Ia- of tmiddot ill tllmiddottJmillaritlu it b [1 hmiddotjlmiddot til IIpoundgt Ir llH1 It liltr ill-llImiddottiT Ina lll ptlPII by it U( in ruhhfl mmly j 11If dtmiddottail fOJ tltt lllllmtlllll If thl plot pet in nlloid ~llntill tltlmiddotlImiddotmiddotlttlatiflll lIOlllllllhtiPI1 are iPllllll page
liTFHFEHliG COIOf
(hi II tht lllail 11111111111 that had til ill -111111 II urklll) om tlH method fot lublJtt tlIlO1 rpir- nlalv~i in plaut llllpll- wa ttl (lilll~ inare tIte (gt1[01 till to tIll ptP-PlHt f xi [aIWIIII- 111 TIlt amount of (olor varip from lUllIt tn -amp ]pplwHlI nlt rhmiddot lt IIf thE Hl(ltllial tllP part of till plllIt -lI11lhmiddot(l tilt hi-tlllY f tlll plaut mtteshyrial ~ub-lltInent to Itlllmiddotnmiddot-rill lliI 1011middotly OrllPI Inlw
In ruhlwr lrtl-i I Iii 1101 au Itmiddot 1Iplll11l by 111[ I--r ratmiddottilt thE -lllll]t with uptoIw or 1middotmiddotlIll-ol - wIdell [llllol- rlll loillriu nutttel autI thtmiddot lpill- Thi- howmiddotvt n(tnll- til lXtla -11gt1 ilt prlJ~edun) In lP-ill ltluay-i nllHufldy tlW[t j 11 1 1IO(PIlln fill the 11shylImya of hlulophyll Hwl rIlI-r middotIOII IHlttlmiddotJ dlH lUtl~ In plltIH withoUt alo aiftIriL till nmiddot ulttrll
111 pllIbIll1l Wi tilmiddotr hId h It-ImiddottHI tht Pltlpll 1 hlitlt lilt tlw tulllWlli tollImiddot uIwltllIIntut -lltUIhorlllllltll 1111 tIll tlettlllliIttwr IIf t 111 lWlrl-Uamiddot of bdt tl11blLlittUhmiddot r [1 tItmiddot preshyj
lipitatifll 1lJ llllllWI atbull 1iI- in III -1nrmiddottIi fHlttalldh nlrillU~ amount rf middotlorilig lIUlttll Iii lhll of ih lltmiddottllllhottohttt~l l~ol()r infrtl Hm II upd 1 rwmiddot tld~middottilmiddottll PlllItlhi~ f it j proYitiltl with tIll lilP--UlY tU(jlIdlllIlml tIltmiddotmiddot lllklllUIlI
EIECTIol OF 1 [EGTH~
-Ptfmiddott ral tracilull ru~lI gtIll fr 1 nllb t ~xtltd 1 lIlt-th vI iobmy1 ketommiddot lWtl rill [ Ixt lttltt ll UttollylaIiIitt1l11I1t~ ~-I itoiu YtHil)u~ typp of ~IHaylllt f i lItmiddot art hraquoil ill fio1ll1 ~l Th~ lp-nlt fill I11oohl uio[1t ttl willlr til tltN- fur rht IUiXtIUt iwliutll
100
22 TECHNICAL BULLErIN 920 U S DEP1
90 bull eo
I shyz 70LLI 0 a LLI a 60
LLI 0 50 z
a ENTIRE 2-MONTH-OLD PLANTS~ 40 b ROOTS AND BRANCHES OF ~ 3-TO 4-YEAR-OLD PLANTSen z WITH LEAVES REMOVED ex 30 a C CURRENT-SEASON GROWTH OF l- )-TO 4-YEAR-OLD PLANTS
20 WITH LEAVES REMOVED
d LEAVES FROM 3-TO 4-VEAR-OLD PLANTS
10 A
0
a Cd 100
b bull
10
80
I-Z 70LLI 0 a LLI 60a
LLI 0 50 z ex I shy 40 ~ en z ltI 30 a I shy
20
10 B
o~__~__~__~~--~--~--~--~----~--~--~ bull350 400 450 500 550 600 650 700 750 BOO 850
WAVE LENGTH lM~)
FJGcm O-Sll((middotlllll tramaniW1IHl (mrpS f(JI (xlmll 11011 n J1ll of jlta)nle tissur ill n 2--m1 Y011111P of (A) Illrthyl ji1I1J1ltsl krtonp 1111(1 (ll) nt(middottQnyla(umiddot tClIc-C(l1osuln a-i
bull
bull
bull
RAPID PHOTOlIElRIC DETEH-UXATroX OF ntBHEIl AXD HEstxs 23
ThE dula Pl(S(l1t(lltl indi(ntp Ihut 101 Illp ulimls llHthyl liohutyl htOlIl (lxtrHts (lI(I r(dolls of Il1Hxi11111III nigtol]gttioll wiH1I all (is-lIb 11 cOllsic1(]((l n1( blhn(11 wn ( ItIl( Its lIO to () I1It~ nlid Ii to Iii mJL
WhllNIS tlw I(gions of 1middottnL(s( light 1lnlllittamp al(l lgtPlW(PIl wan Ipllgtltsnr) to Ii nllt jW) 1I1JL nlld alio Silllill1l 111l1b (n SI(lIlId 101 nc(ton ]altmiddot(fmiddotollp-(llloolp ~ pxt Ill of 11a 1111 t illl TIl( (1101 du( to lolo ill tlw litlltitl a 1Il1 lullll(I tH lPill- hanmiddot bpllI PI(_ ipitated ma he 1((I1((d to fltI ynbhing poillt II ph( illg OJ illshylmiddotJall(( WIWp balld nhm ()) IIIJ1bullbull[1I111 lxjlPIitllll1b Illln -h()1 that Ih( lIIot uilahl( WHYI lHlIJ fOI 1-1 ill 1l11J1l(I HIH11Pill- illllllrsi i-in till IlPighl)()lllll()(l of ~llIl1lt bull
bull UIlIilHlIy of n typhn] lXPllillllllt to )10 l1iP(tiP ((JIlllo( of (ItOIS dul to lOIOl in 1llblnI Hnd Iill xtnumiddott 11(11 IIIIolp t jUl i p1llelll((l ill tub]lL Till llhlllt- 1tpIO]II Hnd ((llll~()h whit-h UI(I ](]Hllilltl n 1I01lllIhb1 01(111 lxt 11111 IIll 1llll)1 nmtp[in I and )(middotills Tid IIlnkl it poiblp nftlI tlIp uplll1tillll or tlll o1PIl( (0 [niH lip 1Iidl1p~ of lI111 11111(( ill lit ll11l1)[1 (llnlIb nlld Ihll
Sl(ll n ol1lliOI with tllP olnl IJllt illiollt HIl Iltlllll llllI (Ill ltllthpl prpipitnnt j Ihll1 nddld OUI ha a lIilPt lP( of till lIiciPlw of WH( lllIgth 7) lUI- ill llilllillatiu (nnl till tll Ixtll1I101l ()lll~
Tuu tmiddot-Elilll IJl flrldillY 11-1111 lrlllI IjfJI til islII 1 1(1 ([rllt IIIIIJIlIr JiIlIt~ if 1Il( Ihll 111111 k til I III Ilrln I 1Intd tf 11111 JiSf fill I I II I tIII Ilf Iilltl 1f1JlIIillII1f I Till 1[ 1 IId 1 (I (middotIt 11111 (I1I1iI1 1lf1IWtlfJlIIllfflr p middottrllhIJ11 II J III 7IImiddotIa 111 111 lilt jJIp 111 wilTII
t~t tnVIli~ ~nn r kn t~ i tmiddot ~~l Jr 1middotmt ltlTt
HmiddotOtt ~I~ lin t I ~ 1 t~~l ~qrmiddotthtmiddotrtwb
Hult-middottltlru t T Hw ullut rHtt~ r II I ~ PH~lllt
A~tmiddottHHjmiddott~rjd rl ~gtllh 1 tn~th~ ~ ~ middotI lt~ b w bull hmiddotth~ 1i~lIhun 1 Ii tnl Illd1 -11lt1(11i lullI lUI tJl ll~ t1~11n( I Ihan1li flfttIJir Ult I Uuhtltt ahuul l(hmiddottHmiddot~t trv r fti HIt lftbyl tlonhUt)1 k_hIl( 2 m~ fmiddotf tuhlHmiddotr In mlth~ llmiddotlf- 1 t r
t r_~ t j
Arhlitlltd ~llIIDHl NcWitn1 ( Ar-(lt()nc~middotttrrtrt ritJJI~ -Iu nllJtl4-middotr
ACtmiddottflnp fmiddotxtrn( ~ T-P511ftf tn mtmiddotth~ 1 ~difmiddotut~ kdn 2 nltt ulruhhtr in Un-tIl lltbu )J~IYt
rUth(Hl~hltlft HhubU
Illlh(I(t tttUtUt hUbtl til J ~jlitl(J Hilllll trtIIImiddotjtl1ll
(UShl I ~tlO wHllolH rulh r (middot1111$0]( J~rru t t )lthyl 15bullbull1middot1101 klll1l
Ili( UHUicbcul ~((i1rUtl ~ulu1iin 1middot lIUIll Ilti lrllltlllt I Ruhhr llt1thuI r1 -1 Irld
ltlt1111Sh 2 nuz f)rruhl~rm nlith~l tu- h f nt nil~middothgt(H] tlrlftmiddot 9lUtirtl middot1 1
rlcltfl( H(l dnllltml it
(IISllhH~rI( Iultruhtr CII05 1v ltTlft I 2 UI~r ublwr In llldh I hlt~1 11) lgtjdvr(llsl~9rlltmiddot middotlmin ~ I~ gt AIHItilltl no IrttipHallr iI
~ Bbnk 10ol m(thyl i~tmiddotut~i kdHn H 1 m1 j~~ l1rH-t lt~tlfltmiddotn sf n it ll HltlMjftr~nol O2~mlJ ~U~1o-ulp ti~tW -xtra~middotl(lt1 ltt 411 ml bull ie f Ct- kft rt t~ tirattJ middott ill r u l1kn ttJt
in metltl isobutyl kNqnf nn~i mljp ur tmiddotmiddot ~oml ~urr tttl i t w ltJj1JH kt 4t 3 nlank 1 mL((l1t~rthmiddot(middot mI mttr~ ~but a kmiddot tmiddotc d 11 ~ gtli~b~ hifIAft- fl~ lL lnti 149
ml8(dlfilll BO bull 02 gm guayule U$Stl(middot xUlClt-l tf(h tft wI n nmiddotmiddotmiddotlgt 1 lznt on tmiddot ~Jt r~1 ~~u~~ H~ iI~ thT
24 l$CHNlQAL BULLETlN l20l S DJltJPT OF AGHl(CLlOHJltJ
In table a is pl(sentc(l such c1il((t edlt1tIHC showing that thc (0101 Ixtrnetccl from guaYIIle tisslIe wit h II(P(OIl( n nd (pl1oso[yc is cll(div(ly sCIe(nec1 out by the s(lp(tion or wnw length )0 miL Oil t1w SI)((IOshyphotonwtpl This tnb]p all-HI ihos thai thl Juhlwl altl(l((1 (nn IJl quall shytitntivcly 1(I(()(Ipltl in tIlt PI(ilIH( or Ih (o]OIplnwPIials and Illsins and tlmt Iuhb(l WtlS nppnlllltly 1I0t (xtltI(((1 110111 11l glll1I1l lisslIt b~ tlHSP SOhlllts Thls( ((suIts ginmiddot (OliIHillg (idJt(( that t Iw IISI of waYl llngth i)ll 1Il) OIl till SppdTophot OIllltPI ii t hl 1101(1 p(oshy(ellule in photolllliTie IlIlalysis of luhhlI OJ l(sin-
SELEGTIO- OF )IOiOCUHO)IAIIC ItIIm ((1111110
On th( basis of th( IPHIlb shoWIl in tabl(l 1 al hlllpls (1( IIln(lp to SPCtl lC the PIO]Wl 11101lO(lIOl1ln til Ii ltlJ ((lIllIJi nIl ions 10 llIiOlS (oIOlimet(Is 111(gt 7W-Ill~ filtpl flllnhwd 101 til( I1~lI1l photoshyplpct1i( (o]oriJl1ltll fol which Ill( (hlll(IlIiitit~ oj t hl Ilda he light ilUIlBlIIhiSioll (t) elll nn -hO11 ill fig1lle 10 iws satlsfa(lolY IPshysultl 111( iiO-mL HitlI olllhintioll 101 whkh ttp (middotIatinmiddot light tlnnsmission (ullmiddotis a 1-0 showlI ill figllll (I is -nthdnlto1 hut this is not stnlHlnld NtllipmPlli
Up to fhl PlPHllt lIS(middotflll pound11((1 (ulllbinntions jn lltl iOO-I11L Iunge hayc nol bllll SlClIlld 101 lhp Klpt 1-1I1l1I11PISOIl (olOlinwtll bu fnltlwl nttCl1lpti 1( )(illg IlIHd
TJIpound OF ST~lmW AFTEH HIIJ1EII Oil HHSIS rlll~CIIITTI(J
~ considl1ltiol1 of ttp lillll of Inlllling af((1 plpeipital ion of 111gt)(1
01 l(sinSTlOIll ollltionis impoltant J(jl~ thC1HI(Plltngp of light IInIlSshy
11 rshy10 f shy
09 f shy ~750 Mil- DOMINANTI
~ 08 cshy I WAVE LENGTH z
I III III i O7 - I III
~06 - 05 shyw
a
Igti= 04 - 720 Mp DOMINANT ct WAVE LENGTH- ~ 03shy
02 f shy
01 t shy 1)O~~~gt~- J 600 700 800 900
WAVE LENGTH (Mp
bull
bull
bullFIGlRt IO- COJllPIUlItiw ~IW(middottltll tlnIlRlllii-lion (II (IllP( 101 1i11(1 olllhinulloll
with dominllnl Il(lllllgths at 720 and 7iO lUi
bull
bull
bull
HAPlD PHQTQlfE1IUC JjETER~lINATION OF Rnmrm AND HEtiINi 25
mitted (spertrophotoll1eleL lCuding-) Ol light (1 (tClcrl (phOlOshyJluol01l1et(L lcndillg~) i~ StlhjNl to (hangl
]fjt~l1le 11 and l~ show that ill til( (asc ot tJaugtIllitteltllight llJHC th~ (x[llliHlllIlnl (oIHlitiOllS tllpl j lilst n dtlln-e ill Pll~(lltngl or UllllslllittnlH( follrnY(l by It ptJiml of lClntin stability with only sliuht (1111 tHn- a f(Pl a lIt1ll1btJ of minutes The light t UIllllitblllll t l(1 ill(Iln~(s This lIIay IJP llllllJltlli7P(ll1 ffl II ow 1Ilt )( f(( darI oliIII tIIlIlNlIlitt(IIIlfJIIlh (iditilIiid Ilil1 pllIipintnl )uoshyIn Of ( 8inx in (~f1( I~iUII i~ Ild stahl I 11 itlll If 1inl nh prlshyilli(ioll of 11l1d(1 II IJIX f) jllIli II (fJJltfiIIlilty slllMI IIriot 1) IIIPldUnl1i tll(I1I rllltltilJl oj tJi~ Jlt jiot IUN ilUf Jxl1 will tIt( tOWI IItlllilil I 1llIlllblJIol I ill I~11l11111 d ill till ifjuids JjOI scnttplltl light 011 till phololltHJIOIl1lttl till dilPCt ion 01 elangl b tlw IPrfIi (If that illrli(atPll rOl tlulll1Jittp(lliuht It Itlll b( llluliJr I-(Pll that if l(middotndlnJ- IIIP mad n itl I t lIP ~()ll1d()lb lpalll this pllioJ of nmiddotlatirp tuigtility tllP llLot tIOllt thi Olll(P (nil bl IPdUCld to tIl lltini III 11 Ill TIll l~adiltg (illH~ bbll Oil tlHl datn rUl lublwls and llsinlt Illl ginll ill tnhh
50 r----------------------------------------------- f shyZ
~ 40 ~----~W~A~V~E~LE~N~G~T~H~7~5~0~M~P~~~~ ~ --------------------=-=-= ~ 30 f- WAVE LENGTH 540 M~ _z _____ ___ -=- __ _ ~ ------shyt ~_=---=-=--I GUAYULEIII 20 -Z HEVEA ltt II KOK-SAGHYZ f shy
4 6 8 10 12 14 (6 18 20 22 24 26 28 30 STANDING TIME (MINUTES)
FIlirtn 11 Emmiddot of wav hll~rh Il li~ltr tlall~lIIit1alHl aftI IUIlItHt -Imlli lug 111m for guaynh llmiddotn 011111 middotiolIlJh~z 1111111 llijlitul1 flolll 1lHlh~ll1Jllryl k11II11l ~(lilltlll h~ lwitlitll 111Inu1 111l~1It1 2)1111 o1U11111 (Helillins on (illllun tlunhll IlIIJlllw]ntllW111 lutl(I[lholtllllltlt with ijUjt Wlnl IHI Ilf1 I
11 EFFEGT OF Hbli 1 -()JXT10~
Tilt lnblwl ~()h(llh pxtnl( till IPillgt ubo It 1m nllu1- bellt -~atea thut ~lll 11-111- tUP olnbhmiddot ill middottIIlIlOl ~1It tlWIIJI( my U)t PIl (tlIHatcl WIth tl1l lullh(t I tahle lJ 1hln 1- -1111 tIll (llllstlOll of nny p()~iblt tITptt of XtIIl11 diflp]lws ill ((JlllPllttUliollS of 1l-in lil lolutioll alollJ with till 1lIltbpl TIU data ill wbh +ho on tIl( hn~is of (olorilllPill ladillU thaI tll( IIUOIl1t of lnbbll Plllipirntld 110111 Ilwthyl olnlld kptOlll olntioll IJ 1li-jHlllnt 1l)04 in 1-llltlIllt ethallol)- not amlll hy thl llllNlI(l of llvin aU1ouut of llins inolution bull
-----
26 rECHNICAL BULLEfiN 920 U S DEPl OF AGRICULlUHE
100
90
80(I) C)
z Ci 70 UI a 0 60 a ~ UI ~ 500 ~ 0 I Il 40
30
A 20
0
100
90
(I) 80 C)
z Ci 70 UI a 0
60a ~ UI E 0 50 ~ 0 I Il
4-0
30
B 20
0
--
--shy ---shy---
2 4 6 6 10 12 14 16
---shy= ~ ~ shy
-
2
025 05
10
15
20
25 -30
35 40
SO
-60
=70 80
16 20 2224 26 26 30
OS
- 10
IS
20
2S
30
35 40
-50
-60 -70 -80
bull MGPE 25-ML
VOLUME
bull
MGPER 25-ML VOLUME
Florm 12-EtTld (If till1l or Slllldill~ 011 light transmittallce (01 (A) gUllyulc lnUIl(I plccipitllitd frOIll llltt h~l isobutyl Ielollt solution Ily neidilic(l ethanul bull null (B) gUllyule ll~illii pre(ipitated flom aeltoll~lllcetOlll-Cl])osolY( 3-7 solushy11011 by H(illilip(i l1U (HPlldillg~ nt -lIlillult Ifllpluls 011 Evelyn photoelectric colorimellr with jU-lllp tlllll alit U-1I11 npN(lle spp also table 2)
bull
bull
RAPID PI-IOlOMEllUC DElEnMINAlION OF RUBBER AND RESINS 27
TADIbullbull ] 4-ReZation of amiddotmount of middottbber pleeipitate(Z Oln metltlIL isobutyl ketone 80lutions by OS-pereent H 2SO in 95-pere(lIIt ethanol to umollnt of resin8 udde(l U8 indivute(Z by colorimetrio readinU8
(Rubber ami resins cnlculntcd on bnsis of amounts in 5middotml ullquuts of extract from 02 gm of tissue in a 2fllll olumo( bull
Hubucl r~cocrell whcll rcsins nddcd as IndIcated Htbbor al1dcd (pllcollt) ---shy
__________bull_________ ~_12rpcrc~15011crccllt 7511crccnt IOOpcrcent
PerCtllt ercellt Percellt Percellt Percent o o o o o) 50 250 263 252 25000 500 500 500 500 700 750 750 751 749
1200 1250 1250 1250 1250
EXTRACTION TEMPEHATURE AND TIME
Typical experiments to detllmine the time required to secure maxishymum extmction of rubber und ltsills at 115deg U Ilre sUlIlmarized in figule 13 the solvents used-methyl isobutyl ketone for rubber anrl Ilcetonylacetone-cellosolve 3-7 for resins extraction-are very eflicicnt since under the conditions indicttted maximum values were secured after 30 minutes of ext1llction The most eflicient liquid for the bath (lig 1) used in extrtlcting rubber or resins is ~ high-grade cylinder oil (S A E ~O) The sand bath and such liquids as glycerol have proved unsatisfactory
RUBBER AND RESINS STANDARDS
According to the National BULeau of Standards 1-_ lhclc Is no gellcrnlly recoglllz(d standard lIIutcrlul [ior II rubber standard] The rubber hydroCllrbon ill llifferent samples of conmlcrciul smoked sheet or pale crepe from heclI pluntlltions nries from l~ 10 04 llercent of the totul nutletmiddot the most 11Ioruble conditions Of preparation
McPherson () has described a procedure for the pLeparation of pure heve~ (Hevea brasiliensis (H B K) MueH Arg) rubber from crude rubber or latex In the absence howevcr of ~ generally recogshyn12ed stalldard for rubber hydlQcllrbon [caoutchouc (CnHUs) xJ the standard adopted was that of the relnthely pure product secured from gunyule tissue txtractiotl nccording to the Spence-CaldweU method (5) or the motlified PIOCCdUlU of Hohnes lind Haasis (p 2) The details for constructing the calibration CULes are given on page 10 Standard rubber samples apparenl-]y can be stored for a long timc under the conditions des(libed on page 10 The duplicate colorimetric lendings for glULyule rubber newly extracted by the modified SpenceshyCaldwell method were ()J2 ench as compared with US) each for the sample extracted by the same method but stored 1 years In each case colorimeter rcadinllS were made on mixtures containing 2 mg of rubber in It 25-1111 Yolume
The selection of tt suitable standurd for guayule resins presents some dilliculties Tll(~ acetone extract of gUllyult estimated on (l gravishymetric busis~ for instance proved to be variable depending on the type of tissue sampled or season of sumpling because such fractions as
COllllllunlcntion dul(lt1 Octohtr 22 11H3
28 QECHNICAL BULLEQIN 920 U S DEPT OF AGRICTTIIlURE
16~==========================115 shy
14 bulli= 13 z ~ 12
ffi II Q
10 c w 9a w
8gto () 7w a
6a w
5en III ) 4 a
3
2
A 00 5 10 20 30 60 90
14~------------------------------------------- bull13
i= 12 z w II ()
a 10 w Q
9 c w 8 a w 7gt o () 6 w a 5 If)
z 4 If)
w 3 a
2
o+B~~__~__~____________~__________~ 5 10 20 30 60 90
HEATING TIME (111 NUTES)
lllGUltE 13-lDffect of time o( lICntillg O2-gm samples of gunynle tissue with solYlIt nt llfio C on lo(OVl)ry of lllhlJer alld 1Isim Lt HlIhblL extracted with methyl isohntyllwtone B resins Cxtll1cted with aCftonyla(etonc-cellosolve 3-7 bull
chlorophyll are weighed along with the resins in the acetone extruct but are not estimated by the present photometric method (fig 0) 1he use of a diffeJent stanclttrd waS therefore indicated
bull
bull
bull
RAPID PHOTOMETRIC DETERMINATION OF HUBBIm AND HESINS 29
The resins standard selected is based on n relatively pure source of resins the rcsinous exudnte 011 the stems of guuyule plants IJldimishynary expeliments with the resi nouS cxuclate from diffcrellt gllayu Ie strains of various ages indicatc nHlt there is little YaLiation in this subshystance on the basis of Colorimct(r readings 011 2-mg aliqllots of 01shypercent solution in It 2i-ml volume (tabl( li) Expelilll(lnts have shown that the air-dried (xuclate contains 3RtOH p(Ic(nt of -volatile matter This material is l(latiyt~ly stablp ill (OlllpoBition and is npshypurpntly on ly slight ly hygroBcopic as shoWIl ill Ia bl(1 1 Tlrp Ipsinolls exudate may be jJleplpd in two wayi-i fl liSP as a stallClHld-(l) the clpan exudate is clripd iol Ghouls at ()1deg C at W indlPs of a(lIum Hnd aftclbCinOglOund ill a molfalis 1)I(spI((I intn airtight COllilinel OL
(2) tllP Cx7lclate is clissolllt1 ill a(lhllll and filtplpd PlactieaJlyall of the acetm1l is thpn lYapolntwl olt OPI a stlam or atCt hath and Ow residue is dripd ground an(( PI(sPIld as ill tllp fin lllethocl Tlwse two prepalHtlolls a1( (ompalpd in ta hlp ) 111( (((tails fOl ~t()lil1g the resins standald and (onstlllcting the calibration CUITPS alc given Oil page ]2
lAIIIg fi-CUIIIllrsoi (lJ lIr-dr(1I IIIIi 1((11 II II-()I-tr((l l(sil~ 11111111(8 of I II 1111Ie
[Colorimetric rrndill~s 011 1~I11 phulll(Iclrie eolorillJct[lr with i~()middotmll (100- to iiOIIIIl) fillcr [lnd 5-1111 lIperture preeipitantl part ofO5middotPIrctllt 10 to 5 paris of IIOj
nupliclllc(oloritwt([
nIl(lin~s (hIlSlcAg~ ofSlmillXo JrNliltlCllt of fPsiJI$ L1Xtlrlntp on 2 IIIg ofplanls fllsins (XIHIIlt~Jwr 25-1111 vol
tII1(1) 1
leflTs Various _ bull ____ bullbullbullbull 3-9 Colll)Josiltrlairmiddotltlricfl bullbullbull nf)2 002
])0____ bullbullbull _bull __ _ bullbull ~-l Composilld (ri d at n5 C in aUmiddotimh lWUUllJ for l (jOuj(ja hours])0______ bullbullbull __ bull ___ bull 3-0 COJIlpositld disso]NI in neptolll f1l1erNl fl(lf()ll( GGO i(jO (Ivaporntld olT OV(1r Stpl1l11 halh TesidlH drl(ld I1t fi5deg ( ill anmiddotinch VIl(Unlll for 0 houlS bull
middot106 __ bullbull _ Jir~c1rild_~_~_ _~_ ~_~ _ ~ ____ _ __ _ OUu GOifina_~ ~ _ ~~_~ ___ _ _fln~ ~~ ~ ___ ~ __ 6(imiddotI tiliA H)[_ ltlu bullbull i18 tisSflOabullbullbullbull__ bullbullbullbullbullbullbullbull lt10bullbullbull _ tillO llitO406__ bullbull __ bullbull __ bull __ __ lt10_ Utl2 fon591_ fo__ bull liGa oOa 406bullbull _ __ lt10bullbullbull_ li5S OM
j Ph( vnluls in Uw Inst COIUIIlIl indieatp thnt gunyulp fesinous (IIHlnt( wlwtlwr dfircl hi Yn(tlLJ1l1 wilh L~ perc(nt loss of volntllt wutl pr or tWl c1rild giVPd npproxil1lnh1ly t Iw snllw colorinwtCr rNHiing- 011 till busis of aliquot~ cOlllniuiug 2 IJI~ of flsillS lXIHlntp l)tIf 25-mI volultl( Ihil- illdicate~ thl11 Uw UITW IJ1flS~ of olnshytile mntl(f prt~(iJlitnt(d gins npproxilllntlly Uw $1II1l (oiOfirnl1tlf ftudiTlJs ns tho ftsidtw A pnlill1jllaf~middot (XIlltrinllnt indicutls thlli th VUllltill muller l(lIlSists of thl Ilrplne oil fmcl ion I5-(1Il gtnplls or rlsitlOtlS (lxudntll gnvll by stPll1U distillation nn Uefllgl of 011111 of jl(lfPlIW oil with npproximHte tilllsity (If OHIi lind lhus rrprlsll1ll( IlPIJroximllt(I~ 01 Jerccllt Of t he original weight 1hls lllrClnlage complrcs wllh 38 llltrC(ntlost by drvinI( in IICllnllJ
aSplusmnUH perceilt or orlginlll weightlosl
The wailnble illfolJllntioll on tlH (ow-JitlPllts of the gunYllle r(~shyillOllS exudate alld tl1( HeetOlIP ext act of gaylp ti~slw is sllIllmarized in this paragraph lYalttI (u) alld also Hangcn-Slllit lind his coworkshyers 16 reported that 20 percent of the resinolls exudate from gUltyulc stems is parthenyl cinnamaie (CHuOH=CHC020 11JI2r) Steam disshy
15 (OIlIJIIIIUicatioll flom A T Haai(II~l11it llId (0011(11 Calif0111 ill Tnfiitnte of Tccllllology Past(IlIJI Jhps( wOlken al Htud~ing the COTlHlitlllllts of the acetone extract and other conlltituellis of guuyule
30 TECHNICAL BULLETIN 920 U S DEPT OF AGRICULTURE
tillation of similar resinous exudate in the writers laborntory has yielded approximately 4 percent of the whole as the telmiddotpene oir fracshytion Haagen-Smit and his eoorktrs nportec1 thttt about 25 percent of the acetone extract from guayule branches is parthenyl cinnamate and 6 percent of the bark (ltortpamp-phlotm) extraet is parthenyl cinshynamate These workers fm-thcI reported that 25 lwletnt of the nc(shytone extract frolll bLllllches is a compound with the tlI1pilicaL formula CBoH400a 1 percent is a compound llwltillg at 2P to 2T5deg C and 1 percent of the extract from the ]eav(s is tl (olllpoulld nwlting at 100
to 1710 1Valtei (6) reported that 3 to -l perc(nt of the tI(eton( txtract
of leaves and flowering StPIllS of guayulc eonsists of waxlike substances soluble in olgallic soln~nts but insoluble in at(l and (on(ent1llted H 2S04 The flactions mentioned on the basis of (onHLTutle esti shymates of amoullts actually isolated tlecoullted for about H ptIcent of the totalncetollt~ so]ubles extracttd from tll( guuYllle 11 rub The other constituents ltlilaill to be i(](ntifi(d
RUBBER AND RESINS CALIBHATION CVHES
Typical culibndioll Clllves iol Iuhbpl and I(sins bas(d 011 (ldtLminttshytions made nccoLdillg to the plocCdmC outlin(d 011 pages middotb to 1G arc shown in figulPS 5 and 1+ The spCdlopliotoll1lttL en (OIOIjlllctCI readings are plottCd on s(lIlilogalitllllliC pappi ag-ail1st (Il 11IbblI (011shy
100 ~ 90
80 ~ 70 ~
z 1amp1 0 II 1amp1 IL
1amp1 0 Z
60
50
40 ~ltI 30 ~ en z ~ ltI II ~ 20 C) ~ oJ
10 o 2 3 4 5 6 7 8 9 10
RU8BER IN 25-ML VOLUME (MG)
bull
bull
bull FI(lURE 14--Ctlihration curve fotmiddot gllftYlIlc lubb01 (Hct(lings Oil COIPIIHlII tlOl1hl(
monochromator SlCClrophotolllet(r with 7fiO-11IL Illtel alld Hllp Wll ( IHlll()
bull
bull
bull
RAPID PHOTOMETRIC DETE~MINATION OF RUBBER AND RESINS 3]
centrations From a casual inspection of these CUlTes it would appeltr that Beers law does not hold Actual tests indicitted that Beers law was applicable only within a narrow range in the upper portion of the curves The analyticlil results on the basis of photornetric readings nre therefore calculated by direct reference to calibration curves or from reference tables of equivalent values bllscd on the cnlibllltion curves
Calibration curves for kok-saghyz alld heyea lI11tulltl rubbers and Buna S (GR-S Chem Gum IV Goodyear) and butyl (GR-I Standshyard Oil Co Protoc) sYJlthetic rubbers are hOWllil1 figure 15 The samples of kok-saghyz rubber were furnished by the Diyision of Rubshy
100
90 ~I) ()
z 0
1amp1 a
~ a
80
70
60
s 1amp1 ~ ~ 0 ~ KOj-SAGHYZ 0 l Il
50
HEVEA~ ~
40
100
90
~ 0 80z Q 70a Co)
a 60 ~ 0 0 x 50Il
40 ~----~~----~------~------~------~--~ o 2 3 4 5
RUBBER IN 25-ML VOLUME(MG)
FmUIlE 15-CaJiblation curves fOl kok-snghyz h(YCII Bunn S lind butyl rubb~ls (Readings on gy((yn photoelectric colorimeter with i20-lIIp filtpl and 6-ml aperture)
32 TECHNICAl BUIJLETIN [)20) 1 S DEP1 OF AGrnCUIlfURE
Iwt Plant JIl(I~t ignlioll of thi BlII(un and (1( l))(parcd according to 11( SPltI1((-Culd (]] (6) PIO(((lllll Hlpt pal( CLPPe was (xtmch(L with acetone blI()Ieit W 1I(gt(11l a ttnlldal(l
SEXSlllVllY Ol~ llETJIonS
By lip pIO((l(II11P olltlillP(l 011 ]Hlg( +n Iowa (lOOl IIIg (11 1111i(l0shygmm (gHlllllla) of 1hblI ill a 2)1111 yoltll1ll (all )(gt dltpltld Oil tltl Col(man (lohlP mOIlWhlOl1lHlOl l-I)((t 101 l1lOt 0111 ci( I ill1ilnlly 001 mg of Iublwr ill a 2J-1ll1 n]ulllP Illay bl Ilad Oil till EnI)1I photoshyllectlie (O]oLillllt(I Thll ya lllll- 011 tilt IHl-i- (J I (xl ad iOI1 fmlll 02 gill of til-lI tH(JI(lillg to tllP -lllndal(l jll()(pdull 1(PIPStlIt IlO()2J tlnd 002) P(IT(lIt of llIbl1ll IPI)(((inly bull1t1lollgh -lI1t low allils can be d((d(middot(1 il lIoullt1 Ill IPtllizpd thnt till PIIOl ill PlI(Plltng( or tll( al110unt dltlIllIilll(J i ltlatlpl high ill tili PIY lo Itlllgl 111 aetllllllladie(middot Ill( lopl lillliL 111)(1(1 lIw (ollllil ions of tlil ]lI()(lltlIIIl u ol1tlinpd ipt at l11 11I1 or 1111gt11(1 illt i-1ll1 Ollllll IlPIPltPlltillg 01 p(gtl(pnt of JllUiJtL un tlll 1Hli or (xlla ion rlOI11 II rlll of tisSIll
EIlIlOH COSIIlIHIIO
In Oldpl to H(IIp ill )1lHtPltt pl((iioll illlpIi1I- it i lH((SSHI to slnlldHIdiz(i rigidly 111( Pl()((dlll( 0 illdi(ntpd Oil pnglt- - to J( If lids i dOlH tlip lXIHlinwnlal PIIll is t(middotdllld 10 n ndninlllill
Illlt pl(iioll of (hI ]lIPPllt 1IHllwd Oil til basi of ]llllP llIllJt1 alld Ipsinssollltions call hI jlldgl(J 110111 figllll Hi lileh lio- til HPIlIgl d(intioll oft -illgIP lI1lnSIlIlIIIlnt in lHi((lltagl of Ill( alllOllllt 01 Illhshy1)() 01 lpsins d((PI1I1 iJlld TIl( (1101 PlI(Plltaglt H1( gi (1 101 OJ) to
RUBBER IN 25-ML VOLUMEMG) 004 01 02 03 04
i= I I IZCtOW
fbA ICtU CtCt WW a
01 02 03 04 05 06 07 08 09 100 = RUBBER (PERCENT)
RUBBER IN 25-ML VOLUME (MG) 10 20 30
~ I CtZ
bBOw Ctu CtCt Ww o I~
010 50 100 150 200 250 RUBBER (PERCENT)
RESINS IN 25-ML VOLUME(MG) 10__ __3-0_ 40 50 60 70 60 90 100--_-- 2_-0
Ct~ -r- 1 I OZ
WCt UCt b C wCtW
a o I I 150 250
RESINS (PERCENT) o 10 50 100 200
bllI 1tI W-Yllnl dtd1 ioll I I 11l1 11IlI11 1(111(11 1 III Plll- IlIIIlol1 01 IIim~
bull
bull
bull solution Il basis J o golH of tiSSII (JlILCl-nt (11(11) for (~I) (l)1 til O 1I1
of luhllpl lin 1 III I (I Ill of lUhlJPl nllll laquo I J to 111 nlg of IlSlllgt (Itllillgs on ]iYllyu pllolwh-llrk CO[IJlilll(-(PI with nOHIP Iiltlr lIntl U-lIll allcrture)
RAPID PHOTOlJElRIC DELEHlllNAllON Cn HUBBER AND H1~SINS 33
10 mg of rubber anel1 to 10 mg of resins in a gJ-m1 yolumC For
bull
bull
bull
comparative ptuposes the leslllts arc also calculated on the basis oJvershycentage rubber OL tltsills in 02 gllI of tissul As WOlllL be expcet(d the error increases sOIlHgthlf for 1(lali nmiddotly low COlHell t1llf iOlls oj rllbbeL or resins The curves in figure 1(j s1l0 that ill til(gt Illlge Ol to 10 pCrshyeent of lubber the elTOI rangts Jroll1 abollt Ll to II) ]IlC(lIt abo(~ this mlllc tIlt (ITOl d(((ts(s to (ollsidlItbly ltmiddotss (han 1 1lICPllt of tlH mllollnt ltl((Lmill(d Hil1lilally in tlH (lISl of l(sins analysis (fig 10) the ltLTor is (onsit1eIubly INS than 1 PlLllnt ill (he lallgp of 11 t~) ~() penPII t
In nil ([lSl of lllhblI alld (sins lx(Inltpd tIOIl1 (issups Ol addcltl to tisslle lxtlads (s(( tabhmiddots (i H) illyolillg ll01P o(lllntiolls the eLI01
is hig]wl thun that indilHtld in figllll ((j Im pUIl Ill )])p I tllllllsins solutlOII
COlllUCIIOXFOH IXSOLl-IlLl~ Ilgsqgt(Jg
111 th( Jllo(pdulP ollllillPd 011 paw I till illsolllhll isSII Ipidll( tflpl (xttlw(ioll is (Ptill tlw lIask l(lll till xtlct i l1wdp up to yoltlllH It is not rOllPllipnt (0 IPt()PI qWlIltitati(Ir III(lw[olH a 11(1 pllooll extlnlfs of guuyull I is-lll alll thl1l main t11l111 up (0 YOIUllllmiddot bpCaUHI sllch all additiollal stltp wottld]) tillll-C(JllS11ll1illg Th( Iogiea nll(gtIshynntin is to mnkp tltl lXtlUCt Llld Ipsidup lip to OllillH in till original flask andi llPSStllY 10 llwlno tl OIIpdioll wlHIl (allIlnting [hc llshy
Hults f(JI [hl oll111lC displupd hy till ins()lllbh llsidll( III it l)picat (IXpednHllt (ollsisting of Jhp lppJiea(iolls if was Iollnd llftt at ~iiO ( 02 gill 01 Iuhhll pillS IPill-fl(( lisslI(gt (lollpdll fot llwistUlC ou basis of dlyillp ut lOW 101 ) llOlll-j (lbp(ld only t~ llllUll voiul11P of OOk7D~- OO(lOO(i Ill of lllthyl bolnl(yl 1lIOll( (lplhlli(al-t(Tnltle sp gl () Ii I ll(Hli (j at ~)) -gtitllP tl1(gt 1It101111( () r t is-lIl xt Iadld j sl1lall til( PlIOI dul to Ill(gt insoll1blp Ip~idll is slllall III [0111 ill( wOtk it (all lJp diIpgal(ll(l
]hcon~lIY OF HllIllgl AiO HESIS AIH)gl) TO EXTlIACI OP
GlYlLE TISSlg
Tnl)ll G L(IHpslntillp (ypi(nl llld(~ SllOS (hat all a plngl of HIOK PlI((nt ot lltl pltl( Ilhl)(l acldpd to tllP Itll h iolJut1 InmiddottcJllP xhnet
of guayulp tiSI1( WllS 1l((PllIl Tlli nllintioll flOlll (olllplpU I((OYshy
PIY i within flll pxp(IiIlHuttllIIOI ~illli]llly fnbll Ii llows thn 1111 llYlIUgl of 1O(1~ ])(I(Pllt of gllllYllII 1(-i1l- add(d to II( (pllosol( (xshytrae of IUllY]l t i~HI Is 1l(oPIPI
THl~ (~ Hf (Off Ill of 1111)( J OJ I~il~ lItfI(( In ~(JI1IJk~ Ilf (111 [lI1Il fI2 lIII
0 tlUfllllit i~~I1
Instrument
---- ----~---- bull shy 1(1
Colemun ruono~ltrOUlllt()r 2t) II sJl~ctroJlhOL()lIIeter with 2tJ I iflllllI wnclength Fetting 21 II nntl 0-1111 WU HI hUJl(L _ L U
Ill 7Evolyn photo~lcclrie (olor JU [ imctcr with iO-llIl filler IV (I
H1 0 t I I
llImiddot lUn WII 1011 HIO Wn mil lUulon
10 JIg1111 IUI ml lUl anh Io aLn 111)_I ) III li lU It 2) deg wn2SU DD
Irl JIll II IIr II US II
1110(1 lULa lUI IlK) IJ WU
I( llI Htl tNI 1(111 2tlNI HI 0 221) lllil t2S 0 1~ 10 1~13
In (I 2117 I
10U 1l(J ~ 4 _H_j ___
9middotJIlJ5 10115 10 00 lUU5 flUU 4li (tl03 9(11)
leIlKl 1l~)5 lOOU l1KIr JOIS un 003 OIl Ii
34 lECHNlCAL BULLErIN 920 U S DEPT OF AGRICULlURE
COMPARISON OF PHOTOMETRIC A1D MODJIoIED SPENCE-CALDWfLL METHODS OF RUBBER ANALYSIS
Guayule samples were analyzed by the photQ111etIic method and by bull the modified Spenc(gt-Cnldwell mcthod The values in table 7 represhyselltativ(I of typical results indieate It -atisfactory dcglpe of conformshyjty between the two methods in thl range of tiSSlHH with llHHC than OJ) percent of rubbtImiddot On the bnsis of the amounts determimd the results in this runge for the plmiddotts(nt lIlcthod ayernge apploxinHltely j percent highcr
~LAIII~ 7-(oIllJl(i~on of lltlllrIic (IIri mOtllinl SJl(II(r-(ulri-wall IIIrtlwrl~ of rlrrlIIillillfl 11)1)(1 COIIrll of UI(III
1 Flowers frllm amiddotmonth-oltl nursery plants
YAIIIATJO- OF SIli(LE DETEnt1NATIONS Fnoll TnEIIllIEAN
Rllbbel (Uall8i8-Thc plcCision of thc pLcsent method when gunyule tissues Hr( nnnlyz((1 for rubber may be j udg(d flom I Ill datil presentcd in table H TIl(se dahl -how that thl pplCPlltag( uriation of single determinatiom from nwan yullles with low standllrd enolS ranges from less than 1 to 4 p(gtrlent
R(8in~ wWlsi-r-s lndi(a((1 011 page ~j he INntlts s((uled hy the present phoolllttric nsins llHt hod are not tliltly (olllpalable with those of the grtLVimetri( ncetol1l-cxtlt1(tioll II1etho(l Thjs made it necesSllry to selc(t another lalibllltion staudud-tlll Ipsinous exullate from gullyule shrub-thut gies relatively COllstlllt photometric readshyings (table 5) The resin (olltents of guayule roots branchcs or leavcs usually ran(~e from about) to 1-1middot pelcellt The ple(ision of the present methotf WhCll gUHyule thslllS lIe analyzed for reins may be judged from the datalHmiddotpscllted ill table 9 1h(se data show that the p(lcelltage variatiun of sillgle lhmiddott(Lminntions iLO11 meun ynlnes with low standard NTOrs rangcs from about 05 to 4 percent
bull
bull
bull
bull
bull
RAPID PHOTOMETHIC DElEruIINAlION OJ RUBBEH AND HESINS 35
IAIILE 8-luriation inclieute rubller (mallSM of [1wIIle tissue bll thc 1111O0Illclc metwII
Vnrlntlon~Ilbher I (rom mean
ierCtnl Percelll ~OU -22 ~ 25 +27 ~ 20 +18 ~UO -22---------1_______ 51110 0G6 bullbullbullbullbullbull _bullbull
10 ro ----=ii41075 -01 1000 +11 1010 +13
rlln HI itil 1l9~ 1_ ___ =-~~~
115511 ~ US -111 III II 1575 -13 115 b tiS -I a 111 h WlU +22IIM-(middot bull 11K -1Ja Illi c 1000 +03 1J5H1 W +l)7 ll1imiddot tl 1575 -13
Mcnn 15951 131
1102-11 21fJ() +21l102-h _ ~~)SO -17 1102-c bullbull 21CO +21n02middotd ~OIiO -26
2 r~plusmn Il~ 21151 261 I -~-------bull---__ _~~_~______l-___--_
1 lhe$ 1111($ I1n (or SlIlIIllltS Stpnnltplr PHrilClld IIrtlrdlng 10 1hr prollIlIlr( OIiIIiIl(o(I on Imgt$ 4 to IC ~tcond nUlI1 hlr r(J)[ltnts stl1ndnnl llrrot of tilt 1I1(1111
1_1l1~ n-J(lri(iot in relli(Upound rpoundsins (lllalIsfs of VIOJII( lixsue b1 the lhomillric lII(lloli
-- ---~--- - __-------- shybull I I I I Varlgttton
_________~___ ~~lu_n_Jl_Q_~~~_____ ______I__~_o~S_J frOID lDean
Percent Percentgt458-1 ~65 +41IWtl-li 130 -a2Hli8c aliO +26S41i8-d bull 130 -32
1(-011 34I10Olifgt __ bullbull __ ~--====
li-9~2n 881) -06 li-9~2-b Si5 o ~HH2middot(middot S i5 -6$-H2middotd 000 +1
8851 054
O i5 +6 9 i5 +6 950 -20 U75 +6
H-liG3o-n bull -1 n-li6~b bull __ _ -IH-IWH +4H-l61511 bull -1
1tmiddottlU
62~-lI __ 62~-b ij24-( bull OH-Ji
(-Ull
I rll(St oluls nre tor separately ~xlrflCled SllllllllCS IlctOrdlug lO procedure outllned ou pages 4 to 10 i Secoud number r~prtgeulS stulldMd error of lIe menn
36 TECHNICAL BULLETIN 920 t ~ DEPT OF A(]RICCLTCRE
ReUUER A~ALYSrS I~ CRCOE-RcuUER PROOCCTS
Sew rapid photometric m(lthod~fol the ddellllinttion of rubber and reii Hi ill uaYllp ti--ut htp lllell pIPHnl pd oil pag( ~l to In A brief H1111111tlY of It similar rnpid llHthod fm 1I1hb~rllnltlysis of u1lulcanizNl tlIldp lubbll pl(Hlmtlt whielt i~ bn-(tldo on the prill o
ciples dehtilcd tlllLe follows Duplltate nt-gm sllmph of the finely cliyiliNl IlInttlitiup wlirllll out [~ei-()l (all hl lIf((tinmiddotjv INd to lt1iyidl till alllpl) TIll kltolll-olubll portion of till )111(11( tlrc di-olved a- indh-Htpd fot thmiddot lllnkill~ of -tlllHlunlluhhll olutiou Oil Pt 1II hut tIl IUlIp Hn lIn l-fplImiddotd 10 lHI-ml rolllllltti( fln-k antil1ltld(lup to Olllll1l The bnlulUp or till JllO(ldllll i- thatutlilllll on paWs -1- 1 IHI Ii 111( 1(111 1- nIP IXPIP--pd nil til IHi or Iw oligiJla w(lullt of I Ill (I11l1p-I1l11Ilt1 1)(0(11(1
Hupitl PlllimiPJojgtiWllllllllh llIltllOd~ fOJ Ihl llPtlmiddotminntion of ImiddotUlJbll tlnd 1(-illo- ill -111111 Illllph of gutlYllll tiUl IIll dl-eli)ed 111() IlltlY d~o Ill nltlI1lld fOl III Iwl Illhlwl- and l~iJlmiddotb(lLiJlg plant TIllt l[Olllhup hns nlo b(l1l ntuptpl fot IIH lltlIll1illtltioll of lllhbpl ill 11lHhrublwl Pl(Jdlld~ HIIl 1111 hI ndaptld JoJ IIll ann lysis of ynt1J(gt( ic lllbbl[- The llllthmb HIP 1gtn(11 fill tIll fol1owill plimiph- III Grinding
tIll PIOPlly driPl t i~lIl 01 Ul tillg tIll pnHhHt to tll l((lllilllllh~lel of filWlH-- til plllllit qIHlIllilnth( lXIIHtioll 01 IIlbhlI 01 1(--IJl- () llsing oXWllutld olnuh (kttoJls IIt(talp and() fllltil for LIbbel and IH(ltIlIlyptIJllIllIoolYlnJld-o flJllh 101 niJlsl with t(lathelr high IlPililig points 111 to n C) l]olle or in mixt tIll thllt Pll mit tlll rnphllxututioll of luhll(l OJ [middot(ill ill ~() to (l mi1lutp It r(latiwly high 1lllIllllltlltP Ill to 1~11 ) l) lllllipitntillu till luhblI OL Imiddot(ill frolll aliquot () f till oltn ion I IlIlllI-i () f Hlltabhmiddot pl(~(i]litallt (willifhmiddotd lthmwl fOl IIlhlHI Hild llitlifild lllr fOJ JP-illl t~) IIlHkillphotollllliilPIIIIiIlof PlllPlltal of liht tLaIlS mittUl(P lIftlI IlIlbll (II Il in PIlipitalioll 11 II WI( Iplllh thnt (limiJlall till PIIOl dill 10 xtralllOlh (0101 (till dptl1minntinll Iph jill 011 tIll dtwlopllIlJIl of H HIli rOI1ll tlllbidity 111 hpl than I (olot rI
jJlIlpOP-ofallnlyi-I ( p(lllil1thb IIllijOI1ll turbidity or 1llt[lIinmiddotd d(ltl of jgtIp(ii(JlI l)~ lIltlkillU tIl plllltollllmiddottri( ntdillU al tandinu tiJlH~ (dlllilll wlli(h IhlllH(lill-- IP 1llutinmiddotly tnhll) t1ll1t an hlsl~1 oil the (oJlItlIlllItion of IIlhlHI Ill I(ill (lIPIipitat((L
TIll -I(p ill till jll()(Plhul HIP 1-- follOylt (1) 1l~UIIL uJ1lplls of thwl UJfJlllHl (II tliddl(l HUt dlipd 11Illtplial an lXIllltel with11 Ill of till nlnll ill t (oU tlllltIPlll[gtPImiddotatlup oil Iath at 11 Cbull fol 11 minutl I) iIP1lIin(middot(lohd til( (XUtllhllll Jltldl lip to It middotml ynlmlll til( (nlifild by (Illlifllgiuu HlId thlPl IlI nliql1ot of tIl (IalioPlllxUlltl nll Uillltlmiddotll(t to l-llll OIlIIlIllril fiuk- (1) For a trial Ilnditlg 0111 III tlll j liJmiddot~t IllHII IIjI to Ohlllll with lilt Pll shy(ilitnnl a 1(11 it 111 (Dod fill llli lIut ( ptotoJIIltlil IPtlllillg-- of pllllntnl or liuht tlUtllIlillal(I oil n (lpel OphotnJlllllI at rase hng-tlt (If 11 llJ Ill Ol It lollllil1lPtImiddott lloyidld with tIll P10]11 I 1110110shy
Ihlolllltt hmiddot Ii1llI Olllhi lIatioll for -1IpItillg UJlproXilll1l tply Wtl P ]Plwth )0 mp are HHlltk TIll Illldillg lliJtaillld fol tIlt 4-milutl tliall(~ll-
bull
bull
bull
RAPID PHOTO~IETRIC DETERIINATIOX OF R(BBER AXD RESINS 37
ing are referred to a table of equhmiddottllut~ previously p1(pa1elt1 on the
bull basis of 4-minute reac1inJ~ for tilE nmge of lot1telltlatiol1- of rubber or resins to bE elHOlll1t(led tmd gidn thtmiddot -tnnlillfr tillIP fill rUbbEt or resins aiter prE(ipitlltiol1 lwfolE photoIllNliI j(tltlill1 un IUade The r(middotnmining dllplllatt aliquot lll then HHllil up te ol1l1Jle and lpoundadillg ale marle ut the -tandillfr tiUlE iudklltll ill rhl tall1lmiddot for the final r(adillg~ -1) 111( milli1lnm or p(tCPlltllt- of lllhbpL (II 1(-in pr(s(nt are rpadholU a prlpan(l table of lquiltlput for tlll photoshymetric readings h1~l(l ill pnell e1-E on pxpPlilmlItal lhln 1111(1 u-ing as stimtlltlds pure luhbll in 1l1bbtl milllYb aIHI guaYllh ll-ill- lxIHlatt~ in resins detNIl1111lttion I
LlTERATlRE CLTED
(1) lUnSbull 1fl36 THE mURMIXTIOS IIF IOTA RE I III OOl THER llT~II
F1 bullrol IlY U(T1l0fll UfSlfi ~rrnrl r flm lt1 KEYS TI Bill Chern 114 44J-l59 illns
t1 ~ICPHHlObullbull T 1J3bull~ lUTHOO roa THE PtRInCAnu Or a(lIUl IRrIlHU It of TIn
PLRIHEU Htllllflt [ i Bill lallllall 111 Rmiddot 711middotj iIlus
I ) RHBERG P B Ul5 A METHIlO Or ~u(ronrll-nl Hi tIII rUIl[1 f71 ii illlI
bull 14 Hoss W flbull and HARDESTY J O
llH IR1ltDII Of HfITilIZfmiddotR DllIJS ltt 1 Yl fll Off gI bern JIIIlI i ~middotmiddotlf IIl
101 SPEltCE D nnd CuoWELr ~I L 1933 DETER~n-ATIOo OF RtBBER Ii nrllllpoundRBfR Iusr 1uI II1 amI
Em~ifl cttIliIa~~ r Ell i 71middot7i l11 (HI WALTER E D
1U44 ISO~nlS OF PRTlltSrr 1trHpoundV bull l UI n W lHHt (Tnmiddot 1ETS FROM GiYI l~iIl lItr Clttrn SII J UI titJ middotn9--C1 ilIu
17 J YOEbullbullr H lO~( roLORIlETRT 771 IPmiddot nl -W Yurk f H Plrwptric hmica
naly-II rimttry lUll XphHHlnmiddot~ y 1 1
11
HI) ~ fPHELolzTRf 57 111bull Lin xw Yk t H lt PhmeHt CblUlmiddot ila AnaiY~l~-(H lithrry and XIhmiddotILpfIY Y wirh enomiddot rrJlllrjr hy H KtlJnJU11 I
t~1I --- and ~ARVER L 1f41 nlua-w ~in L liLhr IS IP ll~ XIW Yrk
bull For-sale by th~ ~a~fr1nt~nf1ent Dt~c~~ogtnts-~ s t1i rArnn~ut Pn~~~ tJffieshy
Washington 5 D C bull Pl lU ~nts
10 TECHNICAL BULLETIN 920 U S DEPT OF AGRICULlURE
25- and 100-m1 volumetric flasks arc rinsed two or thrce times with tap water and then with cleaning solution al1tl watel as is customtny In all cases the rinsed glassware is dried in an inv(ltell position at 100111 temperattlre 01 upright in a drying oven The flasks used IoJ extracshytion of rubber Iron1 kok-sagh)z (Talllrl(((IM1 kO-8aghyz Rodin) are finally rinsed wHh the solvent to be used and are nllmnd to lt1Inin and dry under a ventilated hood Cuwttes 01 absOlption test tubes nre handled and cleaned aH directed by the manufacturC)s of the llhotoshymetric instruments used
RUBBER (CAOUTCHOUC) CALIBRATION CURVES
GENERAL CONSIDEHATIONS
The lubbeL hyclroc~rbon stau(ild is pllpa 1((1 by extracting the rubber from guayule bssue ac(ordll1g to tilt SPCI1((-Caldw(llmethocl (5) 01 by the Holll1lH-HaasiH modification of this method (p 2) The air-dry extraeted ltlbber is dried furtlllr in It vacuum OYCl1 with 30 inches of yaCH1Il11 at 63 0 C for 4 hOlIlH Till rubhlI sbindanl is preshyserved h1 It clos(cl contaim1 sto1(d in It r(fligellltol BCfole th( samples nrc weighe(l out the unopened cOIlbdn(l with the rubber i~ brought again to room tllllpelutnre
Two stock solutions each in triplicate from separately extractml standard rubber satnples nre prepared-the first sct of (-111(( containshying 01 percent 01 1 mg of luhbC1 ])(1 lniHilit(l and the other 02 pershycent 012 mg of rubber pel miJlilit(l TIl( (I(~il(d w(ight of rubb(L contiiinec1 in It known VOlIl11e of th(~ solycntis withdrawn Irom Il
burette or pipetted and made up to 25 m1 the standard volume used throughout the procedu]e
The rubbcr samples (01 and 02 gn1) for the stock solutions are weiOhecl out to an aCClllal) of o~ mg on nn analyti(~al balance The rubber is best mnnipulated by mNlI1S of t1l( stJai~ht hlunt-edged top of It cork knife With a little prnctie( OIl( (an leltlily sepnrate t)w desired portions by pLeSSIl1C from aboye Further subdivision Is mndt on a stout PVllX at(h glnssnt lla~t 2 mill in thlkne~s By pressun f10111 above and sheuling aetlOl1 Ye1~ small pnrbcllH can be separntetl so that the requit((1 11l110unts (un 1)( w(igh((l Ollt accurately The rubber sample is then divided into sl11a11 piC(es on the special watch glass by meanH 01 II coll Imife
One mil1ilit(gtl of lt1i isobutyl ketone 13 js placed in It special 30-m1 trituration beaker (fig ~B) and the fine1y diyilt1ec1lubber sample (01 or 02 gll1) is udd(d and heated on a hot plate under n ventilated hood to Il tempelature jllst under th( boilin~ point of the olvent A special glass rod il used t () t rit II ate the sumple (fig 2 11)
When the rubl)(r hll d issohed so as to makl a hOll1og(J1lOUS geUike 111I1SS hot methyl isohutyl ketone or an oI the other luhb(L solvents recommended (t aIJI( 1) is add(d and niicd with the rubber soltItion
31 Diisoblltyl ketoul WIlS not aailab1p (Juring ValtimC l1Cthyl isolJutylletonC 1II1ly be substitnClt1 11111 it is not a~ Cf1kiCni In Illis olllntion If the IllttC1 is used It is b(SI to pl Ilw fimlr diillPll Iubhpl palll(s slan( oPIuight in Ih( solvCnt lind 10 (OPl til (onlalll1 to IllinilllizC elIpornt(111 of sohPIII bpfolp wa( Is nppliecl to completp nlutioll
bull
bull
bull
bull
bull
bull
RAPID PHOTOMElRIC DElERMINAlIOX OF RUBBER AND RESINS 11
The mixture is tllll1sterled to It 100-ml yolumetlic flask with sevtlul washings of hot solvent cooled to n s(uHluld telllpelatUle and madtmiddot up to volume with the saIne solwlli SlwtiaJ IHl(uutioll mllst be takell in transferring t)( lubbCl solutioll to till YolulIHtrie flask so thnt llO rubber is lost It is cOllytllielit to illSllt It j-ill(h funnel in the ne(k of th(~ voiumptic flask to pOll tll( lubb(ll solut ion ill OIl( OLWlHtion into the tube of tht IUlll1ll with Ihl aid of tIl( glllss Iod nlld 10 follow illlshyl1eilintely with S(gtllnl ~Ynshings of hot S() I(111 whkh lIl lilst pouled 1nto tIll btll PI 1I(ld dIIleUy OW) till 1unn1 aId IhpII t1I1uugh Ill( funnel
H time hi not all objllt it is uls() flasible 10 p1alt Ihp linely diided particles of Iubblt ill tl( flask toJ1tuining Ihl sohPIlI 11(1 allo it 10 stand until til( 1lIbbpI is dissolYld TIl( llIblJll ioluliol)s alp slolpd in Ihe tightly s(ojlP(1(d OIUllwt lit f1nks in a ((lol dark placl Thel they willltIIlUlIl (OlUilallt ill Idut 101 an indlfinit( JlPIiod
Two ellliblHliol1 (IlP~ flIP IIltl(l(-OIl( 101 o~ gill of tisHlIP (ollin illshyhw 0] to 10 PII((Il of rubb(I ((1lt)middot1 to U mg of IlIbb(Iill tt ~)-1Il1 yo1ullll) and th(middot otlHl for ()~ gil) of tisslIp (ollaining 10 10 ~l() peLshycent of lublJPl (O to 10 Illg of lulllJpI ill a ~)-))Jl YOIlII1IP)
(Hns HlJ 111 TO 1 II~IWEX( (II BIIII1EH
III oldl) to ll(llllP (ITOI (0 II Iltinil1lIl1l a lIitahl( lllillobllllltp is lIs((lo Jl((lpn (P IhI ~lt of stal1da Id solut iOlls 0 f a Ii ng (OJllllllllll ious ill til(gt (III)(r( Ol 10 1 gt(I((lIt of LubbI In (11( PI(sPIII WOlk th( 1111shypIoypd HlhlHIg mic)obm(ltp Il bullJ) whkh lIi(IlJalpl dlli(I~ 10 0001 1111 was Toulld sntisiadOlY F(OIll n lll-pltIllllt -talHlulIlllbwl solushytion in HSlIitnbh solnnl lt[lIiIlIUJl1iiat( aliqll()l~or n) Ol o~ n and ()t 1111 al(lllla~UIpd (Jilt ut n stalldUld ~Olllli(lll tlIlIJl(1atulp (~) C ill wlitllmiddots labolulol) I IlIIHIl-of II lllillOillIl(tlt illio ~l-lld yohulI(lie f1nks ploid(d it h gla -(OPIllIS gllollgh of 11ll lubhpl sol Pili i~ thllI addltl to (tl(lt flask to IlIak(1 l 1111 Ill1I IUI(middotc (0 t hl all)ollllt of lllbOPI solutioll ]ll(yiously nd(lpdbullflll DI ntl 01 JlImiddototlmiddottli lolloid solu tillil Iras h(PIl Hddld lIP (bhpl is JlI((i pi III tpd IIlld SP(middot(t )opl)()tolllshyd(gt( 01 (jIOlilllltp) IPallil) an IllHdp 1I((OIdillg to 11ll JlI()(pduJ( Oil shylitwd Oil pagp 1middot1 Th( 1(ldillg~ 101 palmiddotll (OI1((III)Hlioll alp 1I(Iaglt1 anel plotttd Hgaillsl t( ntilligllIlll of 11))1 hI n ~)-1ll1 (jIIlIlH 0) [gt(lClntagl of nlbblI (nltuln(pt 011 tw bnis of tl2-glll lilsul Slllllp1(gts and aliqilOt olulllt IH(IOI 101 (itl ]1I(J((dlll( out lilll(1 Oil pagl 1middot1 This PI()((lhll( i ((l(alld t win ill (a(1 (11( II slandald llIbbllsolushytion was PI(gtllllpd IIOIlI slpa latll XllH(1 ld 1 a utln)(l lllbblI 1 III pips TlwcOlllpl(tpdtlla alp pol(l (1) (loldilla pap(laslrowl1 ill figulp I
Tbl )llO(p(II I ill lllilking a (Uln rOl I to ~ jiI((lIt of JlIlJh(1 i~ simi1t1I to (hat rOl 1Ill l1IlP ImI1 to 1 JllI(PIII (x((pl ill a f(middot dptnils The quinlu]lli(Htl aliqllols a 1( sput(d Ht (lI 12 a j 0 (78 n alld 10 mg ])(gt1 ~i-1Il1 Yolunl III sNuIing thp 01 Illg pll 2)-Jll1 YUlll))lt til( (gtIO(ltlIII( outlillPcl ill IIIl PIp(tding pnltlgllIph is followpd In the rllngl 1 toj Illg )IN ~)-1I11 OtIIl1I Ilw (lsi 1(lt1 (oJ)(tlllltlliollS of lubbpI alP s(gt(ul(gt(l h IlIPHsuljng alhplOi- with Xnlional BIII(atl of Stnndlld~ tltllsf(I pip(Ws flOIl) tltl OI-PlIl(1l1 lII))ll sol III ion
12 TECHNICAL BULLETIN 920 U S DEP1 OIr AGRICULTUHE
RUBBER IN 25-ML VOLUME(MGl
100 1~__middotOT5___ITO___15__2~O=--_bull 2r5_---= bull 3rO__~-_40 bull99
98 shy(I) CI Z
~ 97 ItJ II
~ 96a f-IIJ
e95 o l
94
93
92 ~__~__~__~____L-__~__-L__~L-__~__-L__~
o 1 2 3 4 5 6 7 8 9 10 RUBBER (PERCENT) bull
FIGURE 4-Cnllbrntioll curve for rubber in 02 gill of gt1n~ule tissue containing 01 to 10 p(rcpnt 0 lllbhlI (nlnllillg~ (Ill 1111 J~pl~ll llhooplf(middotttmiddotlc colorimeter with 720middotmu filter und amiddotml uperture the 01 divisions required in actual pracmiddot tice for photometric IclHlings arc olllittltd)
Similarly hl the range 5 to JO mg pel 25-ml Yolume the desired conshycentrations of rnbber urc measured from the O2-pllmiddotcellt solution The complete data lire plotted on semilogtllmiddotithmic pttpel as shown in figure 5 A
STANDARDlZATJON AGAINSL G1IA111 ETlIIU 11 ETHO()
1he alternate ploee(lule of stt121l1ald izing th~ IneHell~ method ngninst the Spellcc-Cald well method (II) altholl~h flaSI hIe 18 not adVIsable because of the extra work J(quiled ancl the introduction of the expershyimental error of the benzene extraction method
HESINS CALlBllATION CUIlVES
The procedure for constructing cal])lation eUlves for resins ttIlulysis is similar to thtni outlinlltl for lubb(l lxcept that resins exndate of gunyule is lIsed as the resins stundard The resinolls exudate disshysolves very readily in the resins solvents listed in table 1 It may be prepared in two ways for use as a stnndard-the clean exudate as bull gathcrcd from the plants is dried for 6110mB nt 65deg C nt a 30-inch ltcuum or the oXllllate is dissolved ill acetone and filtered In drying
bull
bull
bull
RAPID PHOfOMElRIC DJllImlMINAlION OF RUB BEn AND HESINS 13
RUBBER IN 25-MLVOLUME(MG) 2 3 4 5 6 7 8 9 10
r~
eo en ()
90
f--70z Q ~ 60ltl LIJ a ~ a LIJ 40 E 0
0 50
~ 0 ~ I 30 0 ~
A 20 I I
o 25 50 75 100 125 150 175 200 225 250 RU88ER(PERCENT)
RESINS IN 25-MLVOLLIME (MG) 2 3 4 5 6 7 8 9 10
1--90
80
en () 70
I z Q 60ltl LIJ a
50 0
a ~ LIJ 40 E 0 0 ~ I 30 0
B ~I20 o 25 50 75 100 125 150 175 200 225 250
RESINS (PERCENT)
lJIGunE u-Cnlibrutioll cUve for (il) rubhcr in 02 gill of gllnn11c tisme conshytainingl to 2G perc(lt of 11IUU(Il I1na (1]) rpSillS in 02 gill of glI1~l1ll~ tissue (ontnining l to 20 nelecnt oC l(sin8 (U(ndings Oil 1111 E(lI~1I llhotollectlit colorlmeter with 720-mtL filtcr and O-ntJ aperture the lO divisions llquired In uctnul prllctlce for pitotoulPtlie PllllillgS tlre omitted)
in vncuo arelntivply HllHlll qUllntity of (xutlnte is plllcel] in a lalge dish since the mass rOHmS nt the beginning of the drying process Pracshytically ull of the ne(tone is evnpollltpd olf oyer a steam Ol WItter bath and the residue is dli((l pnlYllized in It mortnr and preserved by
14 lECHNLCAL BULLErrN H20 U S DEPl OF AGRICULTURE
drying as indicated for fresh exudate In all ClSeS the products are stored in airtight containers in a dark coul place
The usualllnge of resins from gunyule tissue is about 2 to S percent on a dry-weight basis For work with this plaut therefore on1~ one curve is needed A typiCallesins ealibrntion CUlTe is shown in figure 5B
PnocEDuuE J~OH RUBBER ANALYSIS
Duplicate lXiLllCtiOllS arc made for each tissue analyzed and duplishycate photometric readings are made for each cxtmctioll the final value therefore reportcdreprescnt- nn avcragc based on the four phoshytometric readings
Thoroughly mixed O2-gm samples of the finely ground tissue are weighcd for analysis on the basis of l11oistUlc-frec tissllc The samples arc weighed to an accuracy of 02 mg Oil an analytical balance The method of deriying factors for making eOllections for moisture in samples has been thtailed on page
The weighed samples arc trallsien(c1 to the 2-m1 volumetlic flasks with the aid of l-inch glass funnels and 20 m1 of methyl isobutyl ketone is added to each flask The contents in the Hasks are heated m a constant-temperature oil bath at 115 0 C for 30 minutes uncleI a yentilated hood rhe flasks are removed and any adhering oil on the outside is wiped off with Kleenex 01 H similal cellulose tissue the C011shytents of the flasks am cooled to a standard tempellltule (25 0 in the writers laboratory) in a constant-tempelutllre ater bath provided with a motor stirrer if available and made up to volume with the solvent After the contents are mixed the flasks are allowed to stand for a few minutes until most of the insoluble residue settlcs to the botshytom The extracts are then carefully poured into JO-m1 heavy-duty centrifuge ulJls so as to include as little as possible of the settled insolushyble residue The centrifuge tubes are stoppered with cork stoppers and the liquid is clalifiecl by centrifuging for 10 minutes at 2000 revoshylutions pCI minute The clarified lIquid is poured into 25-m1 volushyl1Ietric flasks plOicled with ground stoppers It i impoJtant to pour off the clalificd (dlart in lWIt a lUlllie that the ill8ol11ble cNi(hwis not Sti1((Z1tp A 1-in(h funllel is plncCd in the neck of the volumetric flask A filter stick (fig 2 D) is inserted in the centrifuge tube through he liquid so that tlH enlnlged palt of the gtiek seals off the insoluble residue and a small portion of the exmet in the cone point 1Vith the index finger the stem of the filtel stick is thell held against the side of the tube towllnl the analyst who holds the tube with the thulllb rmtl t11illt1 fingCl The txtlHct is thell poured off easily into the yohunetlic flask without distnrbing the insoluble residne The COllshytents of the Hasks are then ))ollght to the standard tel11pelatme in the constant-tempentl111e wnter hath
The reagent blank us(d wit h the spectropllOtoll1lter 01 (olorimeter ig prepared as follogtvs ) 1111 of methyl isobutyl ketone 01 other solvent used is pipetted into It 25-m1 yolumetric fiask and 01 ml of protective colloid solution for rubber is added the mixtule is made IIp to olume with acidified Oil-pelcent ethnnol and mixed again the rcquired vo]shylime of the mixture is poured into a cuy(tte or an absorption test tube
From each plir of tissue extractions to 5-1lll aliquots 01 the clarishyfied extlact at the stnndanl tempCraLule ale pipcUed into 2ii-m1 volushy
bull
bull
bull
bull
bull
bull
RAPID P1IOTOMElRIC DETERMINATION Ol~ RUBBEH AND RESINS 15
metric flasks and 01 m1 of protective colloid solution for rubber is added to each One additional5-mL aliquot from each pair of extracshytions is similarly prepared to serve as a key to the standing times for the final readings as indicated in table 2 These additional aliquots are first made up to volume with the precipitant acidified Do-percent ethanol mixed by carefully inverting the flask three or four times] and allowed to stand for 4-minute periods before the reading is made on the colorimeter Vith these preliminary rendings a~ a basis the standing times for final readings are taken from table 2 For example if the colorimeter reading in rubber analysis at 4 minutes is 655 then the standing time is 15 minutes
The two rell1Lining duplicate aliquots for eath extraction are then made up to volume with acidified D5-percent ethanol mixed by careshyfuIly inverting the flask three or four times nnd allowed to stand for the required number of minutes as established by the preliminary 4-minute trial readings (table 2) before the final colorimeter readings are made on the contents of the flasks
TADLE 2-St(llllliIlU time for variolls (OllccntratioIlS Of rubbcr or rcsins aftcl iJleaipitation bcforc colorimetric readings mc macle
[5middotml aliquots of rubber in methyl isobutyl ketone or of rcsill~ in ncetonylncetonemiddotcellosol e 3middoti both made up to a 25middotml volume with pr~cipitantj readings on lvolyn photoGlectric colorimeter with i20middotml (690to iiOmiddotD11) filter and Umiddotml aperture]
RUDDER I
Range of colorimeter Approxima(e S~nuling i Rnnge of colorimeter Approximn(e Standingtrial readings after 4middot range in conmiddot tJIIIG for trini r(adings nfter 4 range in con tifillnlOalcor minute stunding time tcnt In tiSSU(l Unnl I t I t (rending IIlIDU C stum Illg lOW _ tent III Issue reading
Percent Villlits II Perfe~lt Jfinul 955-999 bullbullbull bullbullbullbull 09-01 00 01-03S bullbull ~ _bullbullbullbull_ Jl-O9 10 743-954 bullbullbull ~ bullbullbullbull __ _ 43-10 30 1420-550 bull ~ ~ 137-94 5 6_3_9-_74_2__bullbull_ bullbull bullbullbullbullbullbullbull_-_---- 6__8-_4_4---___ bull ~ ~ bullbull ____ MQrcthan 13ibullbull_-~_ _ ____ 15_~elow t~ 2
RESINS -----------------------------~--------
957-999bullbullbullbull ~ 139-01 60 11419-amp11bullbullbull _bullbullbullbullbull ~~ 13~5-939 10729-956bullbullbullbullbull_ Ii 25-1 middotJO 30 ~gtl2-40(L bullbullbullbullbullbullbullbullbullbullbullbullbull _ 2025-1320 5 595-728~~~ bullbullbullbull 8 as-G 20 20 IBelow 292 bullbullbullbullbullbullbullbull- More thun542-591 _bull ~ bullbullbull_bullbull_bullbullbull 038-039 15 2025 3
I Precipitated with O5middotplrccnt HSO in 05middotpercent ethanol When the npproxilllull concentrntion of rubber or rcsins in solution is not known trinl colorimeter rend
ings atmiddotJ minutes s(nnding till nrc mndelS n guide to the required finnl standing time indicated in the last column III prncticc UII cxtrn nliquot is prcpnred for precipitation and thIs is discarded after the trial reading is mnde
3 lrccipitnicd with OmiddotpcrccntlhSO ill HO
PnOCEDunE I-On UESIliS ANALYSIS
The procedure fol resins unulysis is the same as that indicitted for lubber analysis eomiddot(I]lt that f he -olyent js acetonylacetone-cellosolve ~)-7 tht precipitant js O5-perctnt H~SOI in H 2 0 and 01 1111 of the protective colloid solution for nsins is added to each 25-m1 flask conshytaining the aljquot of the extract before the precipitant is added
PnOlmmlHlC INSlHu~mNTs UECoIUlENDED AND CALCl]IAlION
OF UESurlS
Photometric readings of percentage of light transmittance (T) ale made on the Coltnum double monochromator spectrophotometer at
16 lECHNICAL BULLElIN 920) U S DEPT OF AGHICULlUHE
750-111 wave length or renclings n1( mnde on a colorimeter pLoic1eri with the monochromatic filter eOIl)Il1l1tioJl for sllecting the npploxishymate wfLYe ]cngth at 750 1Il~ For routine deterlllinations the Evelyn photoelectric colorinwt(r ployided with aTW-lllJ filteL is IC(0l1111HIHtll
The liquid in hich the preeipitnted lubber uld rcins are susshypended is pOll(d very cHrdully down the ill~idl of th( clette o absorption tube to lLYoilllllC fOLll1ntioll of ail bllbblls Aft( LUbbet find resins preeipitation wlwn the EnLynpho(otkcllie (olo1imetll is used the readings are nmde nft(L thl standing tillll- hOWll in table~ It has been foulld (OIlllliellt to 11lPtipilatl tublwr 01 llsiIlS from the aliquo(s at ~-millute illtlLvals This allows stlilieipnt tillle to check the eOlolimet(r and to makc 111( lNHlings Vlwll a ehangp is IlltHk fLom onc rending 10 the l1lxt it is advisablp 10 llle the clIvctte 01 absorption tube nt lpast twkp with slllall p(Iltion- of the llllltiol to be leitd
After the colorimd(L lluding lta e becll Iltndp till IlIl II igllIlllS of lubbel or resins or thc lpL(el1hlges pnslnt in Ihe aliqllot are r(u1 from cal ibmti(Hl (urVlS (fig~ 4 and raquo or from plepn Led tables of eqllivallBts baecl ill each (liSP on (x[lerimPlltnl data The results are expressed as percentages of dry weight (S hours drying nt 100deg 0) of the original tissue The errol lltle to lCflyjng the insoluble residtH in tbe voltlllletLie pxtLHclioll flflsk wlwn the pxtrnetis being mnde up to YOlllmC is V(ly slight sinlte only (U gm of tissue is used FOLroutine allalyscs lhis ery slight eLlor mny be dislpgnltec1
EXPERIMENTAL RESULTS
The experilllCnlal reslllts Oil hi(lthp method- of tU)lPI and l(sins analysis a le based ttl( d icussld blicfly hlrehl
PHEPMINrlON OF SAlULES
No difliclllty was expPtitI1(ed in pltparing slmplls of llllrscly-glOrt guayule plants 1pss thnn ~ YPH1S old 101 rllbbpl alld IPSills analysis In the cnl of Odll filld-gl()n gllayull plants PIIOtS hopel mtty be introdmp(l by the custOlllalY Jlwrhod 01 pICpalillg Ihp sampl(s 101
HlutlYHis as is lwipfly i n( ita ttd ill th is s((tion Smh enOlS do llot nffCct the ])lCcisioll O[ t1H llwt hotls for LllbbtL n nd Il~in~ nnn I sis i nee till) are due solely to tIl( tbsup--ampling (llo(pdule in thi (a~e of oldeL field-grown plall TIll 1lllt1lOcl of salllplill7 fipld-gl()l1 plants JllOLC than ~ Y(HrS old thenfort Ieqlliles iurtlHl jnttigntioll
lgtAHnOILr~G FOR HEllOVAL OF UUVLgtS
Parboiling which (onisls in boiling gllltyule plants in water [OJ
8 to 1~ ~ninll(s ~s col1llllonl) uSNl a~ n llHans of Itlli rCnl()y~l prior to drymg nnd gllnllng It I~ tHI([())P ll(e~Sllr to ltItLeLnunc all possiblt~ eflct oi tlti PLOtPlllll( )ll (Il( final results Exp(liments have sh(nm that (helt i- fl Flight loss ill til tmiddotjght of lOO(S and 4(ll1S In I typi(ul lXpelillltll hlu1llHs of ~- ii) -1-ytII-old gllllll( pllllb were Italnd at randolll Olll ( of talns wa- paLllOil((1 and the le~es (1( haIHI-pi(kpd [lom till o( hpJ Ht Both pis (1( dlipd for 48 hOttlS at (i) C in a llI((lwlli(al (011((( ion Oyell Th( lpsult are SUI11111I11izNI itS follows
bull
bull
bull
bull
bull
bull
RAPID PHOTOMETRIC DETERMI~ATIO~ OF IfCBBER A~D HESI~S 17
Dry ucilht lust ill lariOilillf
Plaut (pcrcrllO 1 1 -I2 ___________________ _
213 _____bull _____ bull __ _______ ___ ____________ 12 2(
pound(111_ ______________ 1 R
4_______________ _______________ __ _____
A __ bull __ -_
The efred of parboiling on till final lllalp i SUllllllatmiddoti7(middotd ill figmc G Rubb(1 lecoYelY w(t about 1 percent higher for parigtoillltl plants and lEsills re(ovelY somewhat o-er 1 i)(lr(lllt 10Wlr The (Ii tference in lublH-l r((o-elY cannot be ae(01111tltlt1 fot by loss in dry weight _ due is to be found in a study of thE grinding lwhadol of a parboiled and an unpnrboilEcl shrub The grinding of the patboiled shlub in the hnml111 mill is much fadlitated and ns a rule for tissue with a rubber contCnt below 10 peteent llO aggregates of rubber deelop in the 1Il11ehinr during the (Jpelatioll Yitll the unpnrboilNl shrub some dillictdty may 1)( (lxppliellrl(l Sill(( sOllle of till sti(ky ltxlldutl Oil the plant may scI( u nlldei for the fmllHltioll of lublH1 ngglPgates Til is apparently explnins the npparlllt los in ruhbpl frol1l the llnpariJoiled hrllb as eompnlelt1 with thl palboilld (fig (i) TI1(loss in r(sins
II
RUBBER
10 f-
Ishyz LIJ 0 0 LIJ 0
9 --RUBBER -shy-------shy
-- RES INS -shy---shy-----_
IJ) 8 I--Z IJ)
LIJ 0
0 7 f- RES I NS -0 -shy0 LIJ III III J 6 f shy0
LEAVES REMOVED BY PAFltBOILING
5 f shy -shy - BY HAND PICKING
4 I I I 35 30 25 20
SCREENS (SIZE OF OPENINGS IN MM)
FIGlRE Ii EtIe(t IIf pnlticlp sizE Oil lEcorPQ- of rubber lind (iiil1s when lEgttiye wEre remond hr Pl1liloiling lind h~ hand pi(king ((Dlltrol) plllllt1lt groUlld in t hammer mill
6114038-46-3
18 TECHNICAL BULLETIN 920 U S DEPT OF AGRICULTURE
recowry from pUboil(d shrub may be due to the loss of the resinous exnc1ate during parboiling This exudate forms ns It SClim on top of tlw )iquol in the tank
On the basis of t1wse results the recommendation is made not to yaly the nwthoC of leaf lemoYal in any 011( lNi(lu(h project Then fltirly compalabh IcmLts should he obUiined
70 ~------------------------------------------~ LEAVES REMOVED
BY PAR80lLING ____ BY HAND PICKING
60
-I-Z 1amp1 0 50 a 1amp1 a
en 1amp1 gt1amp1
40en gt-CD Q 1amp1 Z
I shy 1amp1 30 a l shyx C)
1amp1 ~ J 20 I shy 0 I shy
10
O+--L__L-~__L-~~--~~~~~ o 10 20 40 60 80 100
NATIONAL BUREAU OF STANDARDS SIEVES (MESH)
FlGntE T-lJiMlil)utiun of l1Ultkh si~(s of gnll~II( tiSSU( JrIOllll(l in a Ball amp 1ew(1 mill to pass six dllIerNlt S(I(euroII 1(IlYes Iemoved from plants by palmiddot boiling 11(1 hand picking ((olltloll dpfo1iatld plants dried to 1I lUoistufl l0I1t~nt (If 01 to o) 1)(ICl1It ground tiSSlli IbalH1 1() minutes ill II ~i$hel
bull
bull
bull Kahn shuk(f
RAPID PROTOMETRIC DETER~UXATIOX OF RrBBER AXD RESIX-i 19
GHl~DIgtiG
bull Th~ entire pant 01 plant l)iHt a~(gt fl r(ll it pllllIIirU1ry lSillg fur J hours ntGi~ C prIOr tD t 1( plChmll1atmiddot rLlmhll III a II lItmiddot or n Ball amp Jewell mill ~n llltllysis of paldch lzP- nftl~l (oar-( IIindill shows that tlwy ar( about tIlt llllH fOl parbojlP(t awl IJllllluhoileu hrubs I fir 7)
The coalilly gloUllll ample i-- thPll Ildlll forI toUtmiddot at ni C afnr which it ha lllilobtllL(gt output of ~ llllut lII hmiddot- dptPlIIlilwltl by drying submlllpil- at 1110 fot hOtll- TIll 1 IIIIll i lltllt lmiddot0l111d hi a IluninHl mill TIll mo(lel uP(t in thi IIIk i 1I Hu IIIOilll mill as IllUllifill bv Hoss nnt Hartlet ( 1 -[1lt111- with n1ll1l1 pldushyrations ittI lilnbhell b rill HanlIolll V0ll11nHiol1 ElIillllmiddotrill (0 The size lutllihl11 iUlJnole So I ( 111m t ~ II t HUIII Xl) ~ I L~ 111m nnd So 4 lillllU1 11 ttllilhmiddotj 0 r tllP Imiddotlult~ p(lln-It willI t11(e Sll((IIiZtS with )arl)Oiltll awl uil)Jtllboiltd hrlll b lOwl1 in fif1l1fmiddot-- This hows t tnt 1middottttIl ~(I 1 llllll (Up jlllilnl IHlt that
r------~-------r--- ~ --r IHAMMER-MILL SCREEN
O~ NO1
NO2 ---shy U NO 3 ---II
I
bull lL
z
r ------ l 30 ~ gt III
i I Imiddot
i ~ I
I 1 I I
~ 20 I - 1 iii 1[ r 10 ~ ~ ~ I _ ~ I r A bullbull
o bull L-~__~__~~__- ~~ 20 40 60 80 100 40 60 80 100 200
NATIONAL BUREAU OF STANDARDS SIEVES (MESH 1
Yutln I i-tlillltiuli Hf pur id lZt f ~naY1l1 t middotnt r1 lI1 i ~ a hatlltlllI 1IIi11 to 1111 Lx IHtllllH middotIn Lt-anmiddot tIlllunl loy la1 litkh~ omrl t 1) tHul parbuih~ -t B ~ thmiddotfuliufptl ]~lahr thpt tu tt fit t 1 It+gtr-tt1 Jnui~tHn eunttlIt _~rnlitl tl~UP ltakmiddot~~ 10 UddU it~ 1 rtmiddot4~pt~middotK1~r ttakt-middot
bull So 1 gingt- 11 tt-liuin-Iy ltr~pl [lPlItl1tat of iilll 11animiddotImiddot- Eqltrimiddot tIlllll hnnmiddot llOWIl dutr fll llltldllllUU xtlutioH 11pound lnhbll lIl lP-ill frolll IolUlIl ~tlaYlllt tl-IlP by dlt IJwtmiddotlUlmiddot lItlilwd oil Ill 14 - 01
i-mllt 11111- -lwltld hi INd I li~ Ii I TIll lllhtIlttj of Itiu~ So 1 (lltll j thnt 11middotmiddot01middot lttwmiddot to amplil tltt Iollllli tilt art lpdnn ib
IntIIll ll~ i po--ihJI with tI lLllit Ilfltl[lll1t It honld l Plllplw izmiddotl rImt ilt tht h of -allllhmiddot with l lllblPl
~ontlnt of ill PPltllt til lIilll it i tlllt pll--ihl 10 11-middot t(1i Xli L
20 TECHNICAL BULLETIN 920 U S DEPT OF AGRICULlURE
Even with screcn No 2 difficult due to rnbbel tlcrltreCtlltiollS may be ob tl
encountered In thes~ caHeH it iH lWit to parboil the shlub fOL leaf lemonll and finally to dry to about 1 to ~ P(l((llt of tnoiibl1(l pound01 b(~t results jn ~rindillp in tlH hanmHl mill
It iH aclvlsable to provic1l thc hammer mill with a ground wire Hillel the presence of static electric (harges 011 tll(middot partkhH will ealls( Home of these to atlhelc to the inside of tllP (olltailWr OJ lila eallsc OI1l( of till pULticl( to form ngg1(llatls EIIolin lalllpling fl01l1 fhis SOI1I(I mlly be (onsi(h1llbl(middot
A1I10l1g the Holnllts with high boiling point that lIlay Ill IlHld in rubber anal)Hs I1IP Illllhyl n-alllyl ketolle methyl ioblltvl kptOIH diisobutyl (tOIH blltyl tHptate llethyl amyl 1Ittail (middotthyl(middotlllmiddot gly(ol diethvl (middotther and n-bntyl (middotthel (labl( 1) TIHse al( also I(sin 01shy
middotent but th( 1(~illS n1( held ill olution by the rll1)bpl pl(l(ipitant tthanol wll(1 lllbb(r is 1)J(lipitatNI (S(ll tabl(s alldmiddotl) On tIle basishyof the lxpHilllPlltH tll( btsf nil-round lolPlli -rol lS in 111( PIlHPllt method is lt1iisobutyl kPtonc wld(h was not IIltlllllfaltllllmiddotd ltIlling Vodd Yflr n A suitable Sl1lgtstit ute iH llHthyl jolllltyL htolt whi(h is l(porhd as llolltoxit UJ)
Clllos()IY(~ (ethykn( glYlol monopthyl (tIH1) blltyl earlgtitol (di(thyl(ll( gly(ol llIollobutyl (ti1(r)~ and acttonylacetOll( may be used as resins sohrCllts (table ] )
In the earlipr work with (sills analysis cpllosoly( alolle was selcmiddotet(d as a suitable solycnt Aitholllh (ell()~oh( alone is pxc(lllnt its rplllshytiwly gwatlL iscosity 1(I(b to bubbl( formation nft(I (SillS pr((ipi tatioll Thi- increased thp (xperimentnl (LTOI OIl of tltp othll I(sins solpnts tI((tollyla((tolH has the proppry of glpatly lNlulingshydH(OSity 11(11 altld(( 10 othr liquids This sohpnt tlHIeforl wa addp( to ((Uosoh( in slIflici(lJlt tlllIonnl to OPI(0111e the dinieulty On the basis (li~ex)le1inwllts ~ purts oi~ a(donyla((tOlll to I puts of (elloshysoh-f (bolll by olume) as Splldcmiddot(l Thp 01 hel Hoh(nl listed hutyl clLlbitol at l(llst the t((hnieal-g1lld( ploduct uSNl is appal(ntly not as good as eithe of t1w ot1(r two () a (ombinatioll of tlWSt
The SOlVllIts JOI liSt in tumlyzing artifkial lubbel$ hy tlw pr(senf method appllLently (lcllIHl on th(middot kind of llI))(I lIp-ityl (Jxidt is suitable Ol BUlla fi and hutyllthlI for butyllllbbl Tlwse reagents IlLe technical g1lld( Calboll amp CtllUil1t Ch(lllilai (OIP This Hllbjp(( hilS not bepn (XtpllHl(ly illwtigated by till WIit(I
PIIECIIIIJ-
All tlst fOl Ih( adlqlJalY or till IHllipitullb ll(Ollllllentillllll11Sl bl baset] on the plctisioll of tllP final I(snlts oiJtairwd with the methods The )redpittlllts s(1e((( n HpJ (xtcllsi( (xp(IimPlltatioll all HatiH~ factor (Hee fig Hi 111lt1 tabItmiddot (jH) Ext(IIin tllts llllTild Ollt hanmiddot shown that H Hatil-gtflltlOIy [gtIpeipitallt 101 1lIbblI is (li-p(IT(middotnt HzHO (c p reagent nil POll sp gl U-lmiddotJ) ill li-P(l(Put (tinmol by vohmlP liol (tllayul( Ipl-gtinl 1l)-P~ITImiddotllt H)~o ill Hl) by ollln( ii lL satishyfaeto7-y l)lp(ipitunt A solution of 1 palt of H~~o to 1 part of H~() (1-1) iI2So1 nnd abo yarious int(lIlIPdiat( proportions of tlllse suhshystanCPs giyp fait 1(511It8 but with till inlIptl(l ill [h(gt ratio of H~S01
~
bull
bull
bull
bull
bull
RAPID PHOTQlIEfRIC DETEMIlXATIOX OF HtBJER AXD RESIXS 21
to H 20 the )olutioll becollles somewhat vbcou5 and precautioll Il1Ult be taken to ttvoid bubble formation When it i5 poured into tilt Cllvettes
It should be lloted that both of these precipitants have an ftellleshymmiddottion It was found that when XHjOH was used in the rubber preshycipitant in pInt of H~~O~ the readings were -table l)Ut were not reshyproJutihk The lIl of XuOH in pInel of H 2SO j ran nHittble result as a llth H(HY(Pl WIWll til( li-P(l put lthatgtl in lublltl llnalysis or H~O illlP-ius anal)j wn-i uddint(1 thl eharalteliti(s of till liquid with pleeipitated ruhber or resiu in HI~P(ll-ioll n ren1 on the lpNmiddottroshyphotometel m tololinlPtprfollop(1 it lPgnlal lIlll II~ lxplaiHd on pHgP-I (Sl( figs 11 aIlIIl) Tid made it lloible to outain lEPJOshydlHibll tpnlt nntI (onplt1J1(Jttly till JpqnitPIl tlPgJPP of PJPcljoll
IIWIE(TI 1lt COl~101J)
Jtl thp ItJiPl middotxlwlillltnb hefoJ thtmiddot -1l]YIlIt allll pnmiddotdpitallb had lIptll ptoppJly adjutp(l it l fOllll tIuH till llP or a Ploltiw colloid -wll ltIi1)cJ [ttlJmiddotntl- imlIopl tll lmiddotpro]lIibility of the lPlllt JmUkllly ()Ilt 111 U lput lUlU illlihumiddot tOJllPOlUtl tpHd liglyeol teltlut( - llpanlItly IllmiddotlfP(] to lit til I1m t IHflll lImnnmiddott nftlr tlH filial prOIptlllll WtlP dlvPllill1 tlll 11lIlpfit (If thtmiddot [llltlltin lollohl wa Hot 0 natlv I1l(lhmiddotd III rlumiddot Ia- of tmiddot ill tllmiddottJmillaritlu it b [1 hmiddotjlmiddot til IIpoundgt Ir llH1 It liltr ill-llImiddottiT Ina lll ptlPII by it U( in ruhhfl mmly j 11If dtmiddottail fOJ tltt lllllmtlllll If thl plot pet in nlloid ~llntill tltlmiddotlImiddotmiddotlttlatiflll lIOlllllllhtiPI1 are iPllllll page
liTFHFEHliG COIOf
(hi II tht lllail 11111111111 that had til ill -111111 II urklll) om tlH method fot lublJtt tlIlO1 rpir- nlalv~i in plaut llllpll- wa ttl (lilll~ inare tIte (gt1[01 till to tIll ptP-PlHt f xi [aIWIIII- 111 TIlt amount of (olor varip from lUllIt tn -amp ]pplwHlI nlt rhmiddot lt IIf thE Hl(ltllial tllP part of till plllIt -lI11lhmiddot(l tilt hi-tlllY f tlll plaut mtteshyrial ~ub-lltInent to Itlllmiddotnmiddot-rill lliI 1011middotly OrllPI Inlw
In ruhlwr lrtl-i I Iii 1101 au Itmiddot 1Iplll11l by 111[ I--r ratmiddottilt thE -lllll]t with uptoIw or 1middotmiddotlIll-ol - wIdell [llllol- rlll loillriu nutttel autI thtmiddot lpill- Thi- howmiddotvt n(tnll- til lXtla -11gt1 ilt prlJ~edun) In lP-ill ltluay-i nllHufldy tlW[t j 11 1 1IO(PIlln fill the 11shylImya of hlulophyll Hwl rIlI-r middotIOII IHlttlmiddotJ dlH lUtl~ In plltIH withoUt alo aiftIriL till nmiddot ulttrll
111 pllIbIll1l Wi tilmiddotr hId h It-ImiddottHI tht Pltlpll 1 hlitlt lilt tlw tulllWlli tollImiddot uIwltllIIntut -lltUIhorlllllltll 1111 tIll tlettlllliIttwr IIf t 111 lWlrl-Uamiddot of bdt tl11blLlittUhmiddot r [1 tItmiddot preshyj
lipitatifll 1lJ llllllWI atbull 1iI- in III -1nrmiddottIi fHlttalldh nlrillU~ amount rf middotlorilig lIUlttll Iii lhll of ih lltmiddottllllhottohttt~l l~ol()r infrtl Hm II upd 1 rwmiddot tld~middottilmiddottll PlllItlhi~ f it j proYitiltl with tIll lilP--UlY tU(jlIdlllIlml tIltmiddotmiddot lllklllUIlI
EIECTIol OF 1 [EGTH~
-Ptfmiddott ral tracilull ru~lI gtIll fr 1 nllb t ~xtltd 1 lIlt-th vI iobmy1 ketommiddot lWtl rill [ Ixt lttltt ll UttollylaIiIitt1l11I1t~ ~-I itoiu YtHil)u~ typp of ~IHaylllt f i lItmiddot art hraquoil ill fio1ll1 ~l Th~ lp-nlt fill I11oohl uio[1t ttl willlr til tltN- fur rht IUiXtIUt iwliutll
100
22 TECHNICAL BULLErIN 920 U S DEP1
90 bull eo
I shyz 70LLI 0 a LLI a 60
LLI 0 50 z
a ENTIRE 2-MONTH-OLD PLANTS~ 40 b ROOTS AND BRANCHES OF ~ 3-TO 4-YEAR-OLD PLANTSen z WITH LEAVES REMOVED ex 30 a C CURRENT-SEASON GROWTH OF l- )-TO 4-YEAR-OLD PLANTS
20 WITH LEAVES REMOVED
d LEAVES FROM 3-TO 4-VEAR-OLD PLANTS
10 A
0
a Cd 100
b bull
10
80
I-Z 70LLI 0 a LLI 60a
LLI 0 50 z ex I shy 40 ~ en z ltI 30 a I shy
20
10 B
o~__~__~__~~--~--~--~--~----~--~--~ bull350 400 450 500 550 600 650 700 750 BOO 850
WAVE LENGTH lM~)
FJGcm O-Sll((middotlllll tramaniW1IHl (mrpS f(JI (xlmll 11011 n J1ll of jlta)nle tissur ill n 2--m1 Y011111P of (A) Illrthyl ji1I1J1ltsl krtonp 1111(1 (ll) nt(middottQnyla(umiddot tClIc-C(l1osuln a-i
bull
bull
bull
RAPID PHOTOlIElRIC DETEH-UXATroX OF ntBHEIl AXD HEstxs 23
ThE dula Pl(S(l1t(lltl indi(ntp Ihut 101 Illp ulimls llHthyl liohutyl htOlIl (lxtrHts (lI(I r(dolls of Il1Hxi11111III nigtol]gttioll wiH1I all (is-lIb 11 cOllsic1(]((l n1( blhn(11 wn ( ItIl( Its lIO to () I1It~ nlid Ii to Iii mJL
WhllNIS tlw I(gions of 1middottnL(s( light 1lnlllittamp al(l lgtPlW(PIl wan Ipllgtltsnr) to Ii nllt jW) 1I1JL nlld alio Silllill1l 111l1b (n SI(lIlId 101 nc(ton ]altmiddot(fmiddotollp-(llloolp ~ pxt Ill of 11a 1111 t illl TIl( (1101 du( to lolo ill tlw litlltitl a 1Il1 lullll(I tH lPill- hanmiddot bpllI PI(_ ipitated ma he 1((I1((d to fltI ynbhing poillt II ph( illg OJ illshylmiddotJall(( WIWp balld nhm ()) IIIJ1bullbull[1I111 lxjlPIitllll1b Illln -h()1 that Ih( lIIot uilahl( WHYI lHlIJ fOI 1-1 ill 1l11J1l(I HIH11Pill- illllllrsi i-in till IlPighl)()lllll()(l of ~llIl1lt bull
bull UIlIilHlIy of n typhn] lXPllillllllt to )10 l1iP(tiP ((JIlllo( of (ItOIS dul to lOIOl in 1llblnI Hnd Iill xtnumiddott 11(11 IIIIolp t jUl i p1llelll((l ill tub]lL Till llhlllt- 1tpIO]II Hnd ((llll~()h whit-h UI(I ](]Hllilltl n 1I01lllIhb1 01(111 lxt 11111 IIll 1llll)1 nmtp[in I and )(middotills Tid IIlnkl it poiblp nftlI tlIp uplll1tillll or tlll o1PIl( (0 [niH lip 1Iidl1p~ of lI111 11111(( ill lit ll11l1)[1 (llnlIb nlld Ihll
Sl(ll n ol1lliOI with tllP olnl IJllt illiollt HIl Iltlllll llllI (Ill ltllthpl prpipitnnt j Ihll1 nddld OUI ha a lIilPt lP( of till lIiciPlw of WH( lllIgth 7) lUI- ill llilllillatiu (nnl till tll Ixtll1I101l ()lll~
Tuu tmiddot-Elilll IJl flrldillY 11-1111 lrlllI IjfJI til islII 1 1(1 ([rllt IIIIIJIlIr JiIlIt~ if 1Il( Ihll 111111 k til I III Ilrln I 1Intd tf 11111 JiSf fill I I II I tIII Ilf Iilltl 1f1JlIIillII1f I Till 1[ 1 IId 1 (I (middotIt 11111 (I1I1iI1 1lf1IWtlfJlIIllfflr p middottrllhIJ11 II J III 7IImiddotIa 111 111 lilt jJIp 111 wilTII
t~t tnVIli~ ~nn r kn t~ i tmiddot ~~l Jr 1middotmt ltlTt
HmiddotOtt ~I~ lin t I ~ 1 t~~l ~qrmiddotthtmiddotrtwb
Hult-middottltlru t T Hw ullut rHtt~ r II I ~ PH~lllt
A~tmiddottHHjmiddott~rjd rl ~gtllh 1 tn~th~ ~ ~ middotI lt~ b w bull hmiddotth~ 1i~lIhun 1 Ii tnl Illd1 -11lt1(11i lullI lUI tJl ll~ t1~11n( I Ihan1li flfttIJir Ult I Uuhtltt ahuul l(hmiddottHmiddot~t trv r fti HIt lftbyl tlonhUt)1 k_hIl( 2 m~ fmiddotf tuhlHmiddotr In mlth~ llmiddotlf- 1 t r
t r_~ t j
Arhlitlltd ~llIIDHl NcWitn1 ( Ar-(lt()nc~middotttrrtrt ritJJI~ -Iu nllJtl4-middotr
ACtmiddottflnp fmiddotxtrn( ~ T-P511ftf tn mtmiddotth~ 1 ~difmiddotut~ kdn 2 nltt ulruhhtr in Un-tIl lltbu )J~IYt
rUth(Hl~hltlft HhubU
Illlh(I(t tttUtUt hUbtl til J ~jlitl(J Hilllll trtIIImiddotjtl1ll
(UShl I ~tlO wHllolH rulh r (middot1111$0]( J~rru t t )lthyl 15bullbull1middot1101 klll1l
Ili( UHUicbcul ~((i1rUtl ~ulu1iin 1middot lIUIll Ilti lrllltlllt I Ruhhr llt1thuI r1 -1 Irld
ltlt1111Sh 2 nuz f)rruhl~rm nlith~l tu- h f nt nil~middothgt(H] tlrlftmiddot 9lUtirtl middot1 1
rlcltfl( H(l dnllltml it
(IISllhH~rI( Iultruhtr CII05 1v ltTlft I 2 UI~r ublwr In llldh I hlt~1 11) lgtjdvr(llsl~9rlltmiddot middotlmin ~ I~ gt AIHItilltl no IrttipHallr iI
~ Bbnk 10ol m(thyl i~tmiddotut~i kdHn H 1 m1 j~~ l1rH-t lt~tlfltmiddotn sf n it ll HltlMjftr~nol O2~mlJ ~U~1o-ulp ti~tW -xtra~middotl(lt1 ltt 411 ml bull ie f Ct- kft rt t~ tirattJ middott ill r u l1kn ttJt
in metltl isobutyl kNqnf nn~i mljp ur tmiddotmiddot ~oml ~urr tttl i t w ltJj1JH kt 4t 3 nlank 1 mL((l1t~rthmiddot(middot mI mttr~ ~but a kmiddot tmiddotc d 11 ~ gtli~b~ hifIAft- fl~ lL lnti 149
ml8(dlfilll BO bull 02 gm guayule U$Stl(middot xUlClt-l tf(h tft wI n nmiddotmiddotmiddotlgt 1 lznt on tmiddot ~Jt r~1 ~~u~~ H~ iI~ thT
24 l$CHNlQAL BULLETlN l20l S DJltJPT OF AGHl(CLlOHJltJ
In table a is pl(sentc(l such c1il((t edlt1tIHC showing that thc (0101 Ixtrnetccl from guaYIIle tisslIe wit h II(P(OIl( n nd (pl1oso[yc is cll(div(ly sCIe(nec1 out by the s(lp(tion or wnw length )0 miL Oil t1w SI)((IOshyphotonwtpl This tnb]p all-HI ihos thai thl Juhlwl altl(l((1 (nn IJl quall shytitntivcly 1(I(()(Ipltl in tIlt PI(ilIH( or Ih (o]OIplnwPIials and Illsins and tlmt Iuhb(l WtlS nppnlllltly 1I0t (xtltI(((1 110111 11l glll1I1l lisslIt b~ tlHSP SOhlllts Thls( ((suIts ginmiddot (OliIHillg (idJt(( that t Iw IISI of waYl llngth i)ll 1Il) OIl till SppdTophot OIllltPI ii t hl 1101(1 p(oshy(ellule in photolllliTie IlIlalysis of luhhlI OJ l(sin-
SELEGTIO- OF )IOiOCUHO)IAIIC ItIIm ((1111110
On th( basis of th( IPHIlb shoWIl in tabl(l 1 al hlllpls (1( IIln(lp to SPCtl lC the PIO]Wl 11101lO(lIOl1ln til Ii ltlJ ((lIllIJi nIl ions 10 llIiOlS (oIOlimet(Is 111(gt 7W-Ill~ filtpl flllnhwd 101 til( I1~lI1l photoshyplpct1i( (o]oriJl1ltll fol which Ill( (hlll(IlIiitit~ oj t hl Ilda he light ilUIlBlIIhiSioll (t) elll nn -hO11 ill fig1lle 10 iws satlsfa(lolY IPshysultl 111( iiO-mL HitlI olllhintioll 101 whkh ttp (middotIatinmiddot light tlnnsmission (ullmiddotis a 1-0 showlI ill figllll (I is -nthdnlto1 hut this is not stnlHlnld NtllipmPlli
Up to fhl PlPHllt lIS(middotflll pound11((1 (ulllbinntions jn lltl iOO-I11L Iunge hayc nol bllll SlClIlld 101 lhp Klpt 1-1I1l1I11PISOIl (olOlinwtll bu fnltlwl nttCl1lpti 1( )(illg IlIHd
TJIpound OF ST~lmW AFTEH HIIJ1EII Oil HHSIS rlll~CIIITTI(J
~ considl1ltiol1 of ttp lillll of Inlllling af((1 plpeipital ion of 111gt)(1
01 l(sinSTlOIll ollltionis impoltant J(jl~ thC1HI(Plltngp of light IInIlSshy
11 rshy10 f shy
09 f shy ~750 Mil- DOMINANTI
~ 08 cshy I WAVE LENGTH z
I III III i O7 - I III
~06 - 05 shyw
a
Igti= 04 - 720 Mp DOMINANT ct WAVE LENGTH- ~ 03shy
02 f shy
01 t shy 1)O~~~gt~- J 600 700 800 900
WAVE LENGTH (Mp
bull
bull
bullFIGlRt IO- COJllPIUlItiw ~IW(middottltll tlnIlRlllii-lion (II (IllP( 101 1i11(1 olllhinulloll
with dominllnl Il(lllllgths at 720 and 7iO lUi
bull
bull
bull
HAPlD PHQTQlfE1IUC JjETER~lINATION OF Rnmrm AND HEtiINi 25
mitted (spertrophotoll1eleL lCuding-) Ol light (1 (tClcrl (phOlOshyJluol01l1et(L lcndillg~) i~ StlhjNl to (hangl
]fjt~l1le 11 and l~ show that ill til( (asc ot tJaugtIllitteltllight llJHC th~ (x[llliHlllIlnl (oIHlitiOllS tllpl j lilst n dtlln-e ill Pll~(lltngl or UllllslllittnlH( follrnY(l by It ptJiml of lClntin stability with only sliuht (1111 tHn- a f(Pl a lIt1ll1btJ of minutes The light t UIllllitblllll t l(1 ill(Iln~(s This lIIay IJP llllllJltlli7P(ll1 ffl II ow 1Ilt )( f(( darI oliIII tIIlIlNlIlitt(IIIlfJIIlh (iditilIiid Ilil1 pllIipintnl )uoshyIn Of ( 8inx in (~f1( I~iUII i~ Ild stahl I 11 itlll If 1inl nh prlshyilli(ioll of 11l1d(1 II IJIX f) jllIli II (fJJltfiIIlilty slllMI IIriot 1) IIIPldUnl1i tll(I1I rllltltilJl oj tJi~ Jlt jiot IUN ilUf Jxl1 will tIt( tOWI IItlllilil I 1llIlllblJIol I ill I~11l11111 d ill till ifjuids JjOI scnttplltl light 011 till phololltHJIOIl1lttl till dilPCt ion 01 elangl b tlw IPrfIi (If that illrli(atPll rOl tlulll1Jittp(lliuht It Itlll b( llluliJr I-(Pll that if l(middotndlnJ- IIIP mad n itl I t lIP ~()ll1d()lb lpalll this pllioJ of nmiddotlatirp tuigtility tllP llLot tIOllt thi Olll(P (nil bl IPdUCld to tIl lltini III 11 Ill TIll l~adiltg (illH~ bbll Oil tlHl datn rUl lublwls and llsinlt Illl ginll ill tnhh
50 r----------------------------------------------- f shyZ
~ 40 ~----~W~A~V~E~LE~N~G~T~H~7~5~0~M~P~~~~ ~ --------------------=-=-= ~ 30 f- WAVE LENGTH 540 M~ _z _____ ___ -=- __ _ ~ ------shyt ~_=---=-=--I GUAYULEIII 20 -Z HEVEA ltt II KOK-SAGHYZ f shy
4 6 8 10 12 14 (6 18 20 22 24 26 28 30 STANDING TIME (MINUTES)
FIlirtn 11 Emmiddot of wav hll~rh Il li~ltr tlall~lIIit1alHl aftI IUIlItHt -Imlli lug 111m for guaynh llmiddotn 011111 middotiolIlJh~z 1111111 llijlitul1 flolll 1lHlh~ll1Jllryl k11II11l ~(lilltlll h~ lwitlitll 111Inu1 111l~1It1 2)1111 o1U11111 (Helillins on (illllun tlunhll IlIIJlllw]ntllW111 lutl(I[lholtllllltlt with ijUjt Wlnl IHI Ilf1 I
11 EFFEGT OF Hbli 1 -()JXT10~
Tilt lnblwl ~()h(llh pxtnl( till IPillgt ubo It 1m nllu1- bellt -~atea thut ~lll 11-111- tUP olnbhmiddot ill middottIIlIlOl ~1It tlWIIJI( my U)t PIl (tlIHatcl WIth tl1l lullh(t I tahle lJ 1hln 1- -1111 tIll (llllstlOll of nny p()~iblt tITptt of XtIIl11 diflp]lws ill ((JlllPllttUliollS of 1l-in lil lolutioll alollJ with till 1lIltbpl TIU data ill wbh +ho on tIl( hn~is of (olorilllPill ladillU thaI tll( IIUOIl1t of lnbbll Plllipirntld 110111 Ilwthyl olnlld kptOlll olntioll IJ 1li-jHlllnt 1l)04 in 1-llltlIllt ethallol)- not amlll hy thl llllNlI(l of llvin aU1ouut of llins inolution bull
-----
26 rECHNICAL BULLEfiN 920 U S DEPl OF AGRICULlUHE
100
90
80(I) C)
z Ci 70 UI a 0 60 a ~ UI ~ 500 ~ 0 I Il 40
30
A 20
0
100
90
(I) 80 C)
z Ci 70 UI a 0
60a ~ UI E 0 50 ~ 0 I Il
4-0
30
B 20
0
--
--shy ---shy---
2 4 6 6 10 12 14 16
---shy= ~ ~ shy
-
2
025 05
10
15
20
25 -30
35 40
SO
-60
=70 80
16 20 2224 26 26 30
OS
- 10
IS
20
2S
30
35 40
-50
-60 -70 -80
bull MGPE 25-ML
VOLUME
bull
MGPER 25-ML VOLUME
Florm 12-EtTld (If till1l or Slllldill~ 011 light transmittallce (01 (A) gUllyulc lnUIl(I plccipitllitd frOIll llltt h~l isobutyl Ielollt solution Ily neidilic(l ethanul bull null (B) gUllyule ll~illii pre(ipitated flom aeltoll~lllcetOlll-Cl])osolY( 3-7 solushy11011 by H(illilip(i l1U (HPlldillg~ nt -lIlillult Ifllpluls 011 Evelyn photoelectric colorimellr with jU-lllp tlllll alit U-1I11 npN(lle spp also table 2)
bull
bull
RAPID PI-IOlOMEllUC DElEnMINAlION OF RUBBER AND RESINS 27
TADIbullbull ] 4-ReZation of amiddotmount of middottbber pleeipitate(Z Oln metltlIL isobutyl ketone 80lutions by OS-pereent H 2SO in 95-pere(lIIt ethanol to umollnt of resin8 udde(l U8 indivute(Z by colorimetrio readinU8
(Rubber ami resins cnlculntcd on bnsis of amounts in 5middotml ullquuts of extract from 02 gm of tissue in a 2fllll olumo( bull
Hubucl r~cocrell whcll rcsins nddcd as IndIcated Htbbor al1dcd (pllcollt) ---shy
__________bull_________ ~_12rpcrc~15011crccllt 7511crccnt IOOpcrcent
PerCtllt ercellt Percellt Percellt Percent o o o o o) 50 250 263 252 25000 500 500 500 500 700 750 750 751 749
1200 1250 1250 1250 1250
EXTRACTION TEMPEHATURE AND TIME
Typical experiments to detllmine the time required to secure maxishymum extmction of rubber und ltsills at 115deg U Ilre sUlIlmarized in figule 13 the solvents used-methyl isobutyl ketone for rubber anrl Ilcetonylacetone-cellosolve 3-7 for resins extraction-are very eflicicnt since under the conditions indicttted maximum values were secured after 30 minutes of ext1llction The most eflicient liquid for the bath (lig 1) used in extrtlcting rubber or resins is ~ high-grade cylinder oil (S A E ~O) The sand bath and such liquids as glycerol have proved unsatisfactory
RUBBER AND RESINS STANDARDS
According to the National BULeau of Standards 1-_ lhclc Is no gellcrnlly recoglllz(d standard lIIutcrlul [ior II rubber standard] The rubber hydroCllrbon ill llifferent samples of conmlcrciul smoked sheet or pale crepe from heclI pluntlltions nries from l~ 10 04 llercent of the totul nutletmiddot the most 11Ioruble conditions Of preparation
McPherson () has described a procedure for the pLeparation of pure heve~ (Hevea brasiliensis (H B K) MueH Arg) rubber from crude rubber or latex In the absence howevcr of ~ generally recogshyn12ed stalldard for rubber hydlQcllrbon [caoutchouc (CnHUs) xJ the standard adopted was that of the relnthely pure product secured from gunyule tissue txtractiotl nccording to the Spence-CaldweU method (5) or the motlified PIOCCdUlU of Hohnes lind Haasis (p 2) The details for constructing the calibration CULes are given on page 10 Standard rubber samples apparenl-]y can be stored for a long timc under the conditions des(libed on page 10 The duplicate colorimetric lendings for glULyule rubber newly extracted by the modified SpenceshyCaldwell method were ()J2 ench as compared with US) each for the sample extracted by the same method but stored 1 years In each case colorimeter rcadinllS were made on mixtures containing 2 mg of rubber in It 25-1111 Yolume
The selection of tt suitable standurd for guayule resins presents some dilliculties Tll(~ acetone extract of gUllyult estimated on (l gravishymetric busis~ for instance proved to be variable depending on the type of tissue sampled or season of sumpling because such fractions as
COllllllunlcntion dul(lt1 Octohtr 22 11H3
28 QECHNICAL BULLEQIN 920 U S DEPT OF AGRICTTIIlURE
16~==========================115 shy
14 bulli= 13 z ~ 12
ffi II Q
10 c w 9a w
8gto () 7w a
6a w
5en III ) 4 a
3
2
A 00 5 10 20 30 60 90
14~------------------------------------------- bull13
i= 12 z w II ()
a 10 w Q
9 c w 8 a w 7gt o () 6 w a 5 If)
z 4 If)
w 3 a
2
o+B~~__~__~____________~__________~ 5 10 20 30 60 90
HEATING TIME (111 NUTES)
lllGUltE 13-lDffect of time o( lICntillg O2-gm samples of gunynle tissue with solYlIt nt llfio C on lo(OVl)ry of lllhlJer alld 1Isim Lt HlIhblL extracted with methyl isohntyllwtone B resins Cxtll1cted with aCftonyla(etonc-cellosolve 3-7 bull
chlorophyll are weighed along with the resins in the acetone extruct but are not estimated by the present photometric method (fig 0) 1he use of a diffeJent stanclttrd waS therefore indicated
bull
bull
bull
RAPID PHOTOMETRIC DETERMINATION OF HUBBIm AND HESINS 29
The resins standard selected is based on n relatively pure source of resins the rcsinous exudnte 011 the stems of guuyule plants IJldimishynary expeliments with the resi nouS cxuclate from diffcrellt gllayu Ie strains of various ages indicatc nHlt there is little YaLiation in this subshystance on the basis of Colorimct(r readings 011 2-mg aliqllots of 01shypercent solution in It 2i-ml volume (tabl( li) Expelilll(lnts have shown that the air-dried (xuclate contains 3RtOH p(Ic(nt of -volatile matter This material is l(latiyt~ly stablp ill (OlllpoBition and is npshypurpntly on ly slight ly hygroBcopic as shoWIl ill Ia bl(1 1 Tlrp Ipsinolls exudate may be jJleplpd in two wayi-i fl liSP as a stallClHld-(l) the clpan exudate is clripd iol Ghouls at ()1deg C at W indlPs of a(lIum Hnd aftclbCinOglOund ill a molfalis 1)I(spI((I intn airtight COllilinel OL
(2) tllP Cx7lclate is clissolllt1 ill a(lhllll and filtplpd PlactieaJlyall of the acetm1l is thpn lYapolntwl olt OPI a stlam or atCt hath and Ow residue is dripd ground an(( PI(sPIld as ill tllp fin lllethocl Tlwse two prepalHtlolls a1( (ompalpd in ta hlp ) 111( (((tails fOl ~t()lil1g the resins standald and (onstlllcting the calibration CUITPS alc given Oil page ]2
lAIIIg fi-CUIIIllrsoi (lJ lIr-dr(1I IIIIi 1((11 II II-()I-tr((l l(sil~ 11111111(8 of I II 1111Ie
[Colorimetric rrndill~s 011 1~I11 phulll(Iclrie eolorillJct[lr with i~()middotmll (100- to iiOIIIIl) fillcr [lnd 5-1111 lIperture preeipitantl part ofO5middotPIrctllt 10 to 5 paris of IIOj
nupliclllc(oloritwt([
nIl(lin~s (hIlSlcAg~ ofSlmillXo JrNliltlCllt of fPsiJI$ L1Xtlrlntp on 2 IIIg ofplanls fllsins (XIHIIlt~Jwr 25-1111 vol
tII1(1) 1
leflTs Various _ bull ____ bullbullbullbull 3-9 Colll)Josiltrlairmiddotltlricfl bullbullbull nf)2 002
])0____ bullbullbull _bull __ _ bullbull ~-l Composilld (ri d at n5 C in aUmiddotimh lWUUllJ for l (jOuj(ja hours])0______ bullbullbull __ bull ___ bull 3-0 COJIlpositld disso]NI in neptolll f1l1erNl fl(lf()ll( GGO i(jO (Ivaporntld olT OV(1r Stpl1l11 halh TesidlH drl(ld I1t fi5deg ( ill anmiddotinch VIl(Unlll for 0 houlS bull
middot106 __ bullbull _ Jir~c1rild_~_~_ _~_ ~_~ _ ~ ____ _ __ _ OUu GOifina_~ ~ _ ~~_~ ___ _ _fln~ ~~ ~ ___ ~ __ 6(imiddotI tiliA H)[_ ltlu bullbull i18 tisSflOabullbullbullbull__ bullbullbullbullbullbullbullbull lt10bullbullbull _ tillO llitO406__ bullbull __ bullbull __ bull __ __ lt10_ Utl2 fon591_ fo__ bull liGa oOa 406bullbull _ __ lt10bullbullbull_ li5S OM
j Ph( vnluls in Uw Inst COIUIIlIl indieatp thnt gunyulp fesinous (IIHlnt( wlwtlwr dfircl hi Yn(tlLJ1l1 wilh L~ perc(nt loss of volntllt wutl pr or tWl c1rild giVPd npproxil1lnh1ly t Iw snllw colorinwtCr rNHiing- 011 till busis of aliquot~ cOlllniuiug 2 IJI~ of flsillS lXIHlntp l)tIf 25-mI volultl( Ihil- illdicate~ thl11 Uw UITW IJ1flS~ of olnshytile mntl(f prt~(iJlitnt(d gins npproxilllntlly Uw $1II1l (oiOfirnl1tlf ftudiTlJs ns tho ftsidtw A pnlill1jllaf~middot (XIlltrinllnt indicutls thlli th VUllltill muller l(lIlSists of thl Ilrplne oil fmcl ion I5-(1Il gtnplls or rlsitlOtlS (lxudntll gnvll by stPll1U distillation nn Uefllgl of 011111 of jl(lfPlIW oil with npproximHte tilllsity (If OHIi lind lhus rrprlsll1ll( IlPIJroximllt(I~ 01 Jerccllt Of t he original weight 1hls lllrClnlage complrcs wllh 38 llltrC(ntlost by drvinI( in IICllnllJ
aSplusmnUH perceilt or orlginlll weightlosl
The wailnble illfolJllntioll on tlH (ow-JitlPllts of the gunYllle r(~shyillOllS exudate alld tl1( HeetOlIP ext act of gaylp ti~slw is sllIllmarized in this paragraph lYalttI (u) alld also Hangcn-Slllit lind his coworkshyers 16 reported that 20 percent of the resinolls exudate from gUltyulc stems is parthenyl cinnamaie (CHuOH=CHC020 11JI2r) Steam disshy
15 (OIlIJIIIIUicatioll flom A T Haai(II~l11it llId (0011(11 Calif0111 ill Tnfiitnte of Tccllllology Past(IlIJI Jhps( wOlken al Htud~ing the COTlHlitlllllts of the acetone extract and other conlltituellis of guuyule
30 TECHNICAL BULLETIN 920 U S DEPT OF AGRICULTURE
tillation of similar resinous exudate in the writers laborntory has yielded approximately 4 percent of the whole as the telmiddotpene oir fracshytion Haagen-Smit and his eoorktrs nportec1 thttt about 25 percent of the acetone extract from guayule branches is parthenyl cinnamate and 6 percent of the bark (ltortpamp-phlotm) extraet is parthenyl cinshynamate These workers fm-thcI reported that 25 lwletnt of the nc(shytone extract frolll bLllllches is a compound with the tlI1pilicaL formula CBoH400a 1 percent is a compound llwltillg at 2P to 2T5deg C and 1 percent of the extract from the ]eav(s is tl (olllpoulld nwlting at 100
to 1710 1Valtei (6) reported that 3 to -l perc(nt of the tI(eton( txtract
of leaves and flowering StPIllS of guayulc eonsists of waxlike substances soluble in olgallic soln~nts but insoluble in at(l and (on(ent1llted H 2S04 The flactions mentioned on the basis of (onHLTutle esti shymates of amoullts actually isolated tlecoullted for about H ptIcent of the totalncetollt~ so]ubles extracttd from tll( guuYllle 11 rub The other constituents ltlilaill to be i(](ntifi(d
RUBBER AND RESINS CALIBHATION CVHES
Typical culibndioll Clllves iol Iuhbpl and I(sins bas(d 011 (ldtLminttshytions made nccoLdillg to the plocCdmC outlin(d 011 pages middotb to 1G arc shown in figulPS 5 and 1+ The spCdlopliotoll1lttL en (OIOIjlllctCI readings are plottCd on s(lIlilogalitllllliC pappi ag-ail1st (Il 11IbblI (011shy
100 ~ 90
80 ~ 70 ~
z 1amp1 0 II 1amp1 IL
1amp1 0 Z
60
50
40 ~ltI 30 ~ en z ~ ltI II ~ 20 C) ~ oJ
10 o 2 3 4 5 6 7 8 9 10
RU8BER IN 25-ML VOLUME (MG)
bull
bull
bull FI(lURE 14--Ctlihration curve fotmiddot gllftYlIlc lubb01 (Hct(lings Oil COIPIIHlII tlOl1hl(
monochromator SlCClrophotolllet(r with 7fiO-11IL Illtel alld Hllp Wll ( IHlll()
bull
bull
bull
RAPID PHOTOMETRIC DETE~MINATION OF RUBBER AND RESINS 3]
centrations From a casual inspection of these CUlTes it would appeltr that Beers law does not hold Actual tests indicitted that Beers law was applicable only within a narrow range in the upper portion of the curves The analyticlil results on the basis of photornetric readings nre therefore calculated by direct reference to calibration curves or from reference tables of equivalent values bllscd on the cnlibllltion curves
Calibration curves for kok-saghyz alld heyea lI11tulltl rubbers and Buna S (GR-S Chem Gum IV Goodyear) and butyl (GR-I Standshyard Oil Co Protoc) sYJlthetic rubbers are hOWllil1 figure 15 The samples of kok-saghyz rubber were furnished by the Diyision of Rubshy
100
90 ~I) ()
z 0
1amp1 a
~ a
80
70
60
s 1amp1 ~ ~ 0 ~ KOj-SAGHYZ 0 l Il
50
HEVEA~ ~
40
100
90
~ 0 80z Q 70a Co)
a 60 ~ 0 0 x 50Il
40 ~----~~----~------~------~------~--~ o 2 3 4 5
RUBBER IN 25-ML VOLUME(MG)
FmUIlE 15-CaJiblation curves fOl kok-snghyz h(YCII Bunn S lind butyl rubb~ls (Readings on gy((yn photoelectric colorimeter with i20-lIIp filtpl and 6-ml aperture)
32 TECHNICAl BUIJLETIN [)20) 1 S DEP1 OF AGrnCUIlfURE
Iwt Plant JIl(I~t ignlioll of thi BlII(un and (1( l))(parcd according to 11( SPltI1((-Culd (]] (6) PIO(((lllll Hlpt pal( CLPPe was (xtmch(L with acetone blI()Ieit W 1I(gt(11l a ttnlldal(l
SEXSlllVllY Ol~ llETJIonS
By lip pIO((l(II11P olltlillP(l 011 ]Hlg( +n Iowa (lOOl IIIg (11 1111i(l0shygmm (gHlllllla) of 1hblI ill a 2)1111 yoltll1ll (all )(gt dltpltld Oil tltl Col(man (lohlP mOIlWhlOl1lHlOl l-I)((t 101 l1lOt 0111 ci( I ill1ilnlly 001 mg of Iublwr ill a 2J-1ll1 n]ulllP Illay bl Ilad Oil till EnI)1I photoshyllectlie (O]oLillllt(I Thll ya lllll- 011 tilt IHl-i- (J I (xl ad iOI1 fmlll 02 gill of til-lI tH(JI(lillg to tllP -lllndal(l jll()(pdull 1(PIPStlIt IlO()2J tlnd 002) P(IT(lIt of llIbl1ll IPI)(((inly bull1t1lollgh -lI1t low allils can be d((d(middot(1 il lIoullt1 Ill IPtllizpd thnt till PIIOl ill PlI(Plltng( or tll( al110unt dltlIllIilll(J i ltlatlpl high ill tili PIY lo Itlllgl 111 aetllllllladie(middot Ill( lopl lillliL 111)(1(1 lIw (ollllil ions of tlil ]lI()(lltlIIIl u ol1tlinpd ipt at l11 11I1 or 1111gt11(1 illt i-1ll1 Ollllll IlPIPltPlltillg 01 p(gtl(pnt of JllUiJtL un tlll 1Hli or (xlla ion rlOI11 II rlll of tisSIll
EIlIlOH COSIIlIHIIO
In Oldpl to H(IIp ill )1lHtPltt pl((iioll illlpIi1I- it i lH((SSHI to slnlldHIdiz(i rigidly 111( Pl()((dlll( 0 illdi(ntpd Oil pnglt- - to J( If lids i dOlH tlip lXIHlinwnlal PIIll is t(middotdllld 10 n ndninlllill
Illlt pl(iioll of (hI ]lIPPllt 1IHllwd Oil til basi of ]llllP llIllJt1 alld Ipsinssollltions call hI jlldgl(J 110111 figllll Hi lileh lio- til HPIlIgl d(intioll oft -illgIP lI1lnSIlIlIIIlnt in lHi((lltagl of Ill( alllOllllt 01 Illhshy1)() 01 lpsins d((PI1I1 iJlld TIl( (1101 PlI(Plltaglt H1( gi (1 101 OJ) to
RUBBER IN 25-ML VOLUMEMG) 004 01 02 03 04
i= I I IZCtOW
fbA ICtU CtCt WW a
01 02 03 04 05 06 07 08 09 100 = RUBBER (PERCENT)
RUBBER IN 25-ML VOLUME (MG) 10 20 30
~ I CtZ
bBOw Ctu CtCt Ww o I~
010 50 100 150 200 250 RUBBER (PERCENT)
RESINS IN 25-ML VOLUME(MG) 10__ __3-0_ 40 50 60 70 60 90 100--_-- 2_-0
Ct~ -r- 1 I OZ
WCt UCt b C wCtW
a o I I 150 250
RESINS (PERCENT) o 10 50 100 200
bllI 1tI W-Yllnl dtd1 ioll I I 11l1 11IlI11 1(111(11 1 III Plll- IlIIIlol1 01 IIim~
bull
bull
bull solution Il basis J o golH of tiSSII (JlILCl-nt (11(11) for (~I) (l)1 til O 1I1
of luhllpl lin 1 III I (I Ill of lUhlJPl nllll laquo I J to 111 nlg of IlSlllgt (Itllillgs on ]iYllyu pllolwh-llrk CO[IJlilll(-(PI with nOHIP Iiltlr lIntl U-lIll allcrture)
RAPID PHOTOlJElRIC DELEHlllNAllON Cn HUBBER AND H1~SINS 33
10 mg of rubber anel1 to 10 mg of resins in a gJ-m1 yolumC For
bull
bull
bull
comparative ptuposes the leslllts arc also calculated on the basis oJvershycentage rubber OL tltsills in 02 gllI of tissul As WOlllL be expcet(d the error increases sOIlHgthlf for 1(lali nmiddotly low COlHell t1llf iOlls oj rllbbeL or resins The curves in figure 1(j s1l0 that ill til(gt Illlge Ol to 10 pCrshyeent of lubber the elTOI rangts Jroll1 abollt Ll to II) ]IlC(lIt abo(~ this mlllc tIlt (ITOl d(((ts(s to (ollsidlItbly ltmiddotss (han 1 1lICPllt of tlH mllollnt ltl((Lmill(d Hil1lilally in tlH (lISl of l(sins analysis (fig 10) the ltLTor is (onsit1eIubly INS than 1 PlLllnt ill (he lallgp of 11 t~) ~() penPII t
In nil ([lSl of lllhblI alld (sins lx(Inltpd tIOIl1 (issups Ol addcltl to tisslle lxtlads (s(( tabhmiddots (i H) illyolillg ll01P o(lllntiolls the eLI01
is hig]wl thun that indilHtld in figllll ((j Im pUIl Ill )])p I tllllllsins solutlOII
COlllUCIIOXFOH IXSOLl-IlLl~ Ilgsqgt(Jg
111 th( Jllo(pdulP ollllillPd 011 paw I till illsolllhll isSII Ipidll( tflpl (xttlw(ioll is (Ptill tlw lIask l(lll till xtlct i l1wdp up to yoltlllH It is not rOllPllipnt (0 IPt()PI qWlIltitati(Ir III(lw[olH a 11(1 pllooll extlnlfs of guuyull I is-lll alll thl1l main t11l111 up (0 YOIUllllmiddot bpCaUHI sllch all additiollal stltp wottld]) tillll-C(JllS11ll1illg Th( Iogiea nll(gtIshynntin is to mnkp tltl lXtlUCt Llld Ipsidup lip to OllillH in till original flask andi llPSStllY 10 llwlno tl OIIpdioll wlHIl (allIlnting [hc llshy
Hults f(JI [hl oll111lC displupd hy till ins()lllbh llsidll( III it l)picat (IXpednHllt (ollsisting of Jhp lppJiea(iolls if was Iollnd llftt at ~iiO ( 02 gill 01 Iuhhll pillS IPill-fl(( lisslI(gt (lollpdll fot llwistUlC ou basis of dlyillp ut lOW 101 ) llOlll-j (lbp(ld only t~ llllUll voiul11P of OOk7D~- OO(lOO(i Ill of lllthyl bolnl(yl 1lIOll( (lplhlli(al-t(Tnltle sp gl () Ii I ll(Hli (j at ~)) -gtitllP tl1(gt 1It101111( () r t is-lIl xt Iadld j sl1lall til( PlIOI dul to Ill(gt insoll1blp Ip~idll is slllall III [0111 ill( wOtk it (all lJp diIpgal(ll(l
]hcon~lIY OF HllIllgl AiO HESIS AIH)gl) TO EXTlIACI OP
GlYlLE TISSlg
Tnl)ll G L(IHpslntillp (ypi(nl llld(~ SllOS (hat all a plngl of HIOK PlI((nt ot lltl pltl( Ilhl)(l acldpd to tllP Itll h iolJut1 InmiddottcJllP xhnet
of guayulp tiSI1( WllS 1l((PllIl Tlli nllintioll flOlll (olllplpU I((OYshy
PIY i within flll pxp(IiIlHuttllIIOI ~illli]llly fnbll Ii llows thn 1111 llYlIUgl of 1O(1~ ])(I(Pllt of gllllYllII 1(-i1l- add(d to II( (pllosol( (xshytrae of IUllY]l t i~HI Is 1l(oPIPI
THl~ (~ Hf (Off Ill of 1111)( J OJ I~il~ lItfI(( In ~(JI1IJk~ Ilf (111 [lI1Il fI2 lIII
0 tlUfllllit i~~I1
Instrument
---- ----~---- bull shy 1(1
Colemun ruono~ltrOUlllt()r 2t) II sJl~ctroJlhOL()lIIeter with 2tJ I iflllllI wnclength Fetting 21 II nntl 0-1111 WU HI hUJl(L _ L U
Ill 7Evolyn photo~lcclrie (olor JU [ imctcr with iO-llIl filler IV (I
H1 0 t I I
llImiddot lUn WII 1011 HIO Wn mil lUulon
10 JIg1111 IUI ml lUl anh Io aLn 111)_I ) III li lU It 2) deg wn2SU DD
Irl JIll II IIr II US II
1110(1 lULa lUI IlK) IJ WU
I( llI Htl tNI 1(111 2tlNI HI 0 221) lllil t2S 0 1~ 10 1~13
In (I 2117 I
10U 1l(J ~ 4 _H_j ___
9middotJIlJ5 10115 10 00 lUU5 flUU 4li (tl03 9(11)
leIlKl 1l~)5 lOOU l1KIr JOIS un 003 OIl Ii
34 lECHNlCAL BULLErIN 920 U S DEPT OF AGRICULlURE
COMPARISON OF PHOTOMETRIC A1D MODJIoIED SPENCE-CALDWfLL METHODS OF RUBBER ANALYSIS
Guayule samples were analyzed by the photQ111etIic method and by bull the modified Spenc(gt-Cnldwell mcthod The values in table 7 represhyselltativ(I of typical results indieate It -atisfactory dcglpe of conformshyjty between the two methods in thl range of tiSSlHH with llHHC than OJ) percent of rubbtImiddot On the bnsis of the amounts determimd the results in this runge for the plmiddotts(nt lIlcthod ayernge apploxinHltely j percent highcr
~LAIII~ 7-(oIllJl(i~on of lltlllrIic (IIri mOtllinl SJl(II(r-(ulri-wall IIIrtlwrl~ of rlrrlIIillillfl 11)1)(1 COIIrll of UI(III
1 Flowers frllm amiddotmonth-oltl nursery plants
YAIIIATJO- OF SIli(LE DETEnt1NATIONS Fnoll TnEIIllIEAN
Rllbbel (Uall8i8-Thc plcCision of thc pLcsent method when gunyule tissues Hr( nnnlyz((1 for rubber may be j udg(d flom I Ill datil presentcd in table H TIl(se dahl -how that thl pplCPlltag( uriation of single determinatiom from nwan yullles with low standllrd enolS ranges from less than 1 to 4 p(gtrlent
R(8in~ wWlsi-r-s lndi(a((1 011 page ~j he INntlts s((uled hy the present phoolllttric nsins llHt hod are not tliltly (olllpalable with those of the grtLVimetri( ncetol1l-cxtlt1(tioll II1etho(l Thjs made it necesSllry to selc(t another lalibllltion staudud-tlll Ipsinous exullate from gullyule shrub-thut gies relatively COllstlllt photometric readshyings (table 5) The resin (olltents of guayule roots branchcs or leavcs usually ran(~e from about) to 1-1middot pelcellt The ple(ision of the present methotf WhCll gUHyule thslllS lIe analyzed for reins may be judged from the datalHmiddotpscllted ill table 9 1h(se data show that the p(lcelltage variatiun of sillgle lhmiddott(Lminntions iLO11 meun ynlnes with low standard NTOrs rangcs from about 05 to 4 percent
bull
bull
bull
bull
bull
RAPID PHOTOMETHIC DElEruIINAlION OJ RUBBEH AND HESINS 35
IAIILE 8-luriation inclieute rubller (mallSM of [1wIIle tissue bll thc 1111O0Illclc metwII
Vnrlntlon~Ilbher I (rom mean
ierCtnl Percelll ~OU -22 ~ 25 +27 ~ 20 +18 ~UO -22---------1_______ 51110 0G6 bullbullbullbullbullbull _bullbull
10 ro ----=ii41075 -01 1000 +11 1010 +13
rlln HI itil 1l9~ 1_ ___ =-~~~
115511 ~ US -111 III II 1575 -13 115 b tiS -I a 111 h WlU +22IIM-(middot bull 11K -1Ja Illi c 1000 +03 1J5H1 W +l)7 ll1imiddot tl 1575 -13
Mcnn 15951 131
1102-11 21fJ() +21l102-h _ ~~)SO -17 1102-c bullbull 21CO +21n02middotd ~OIiO -26
2 r~plusmn Il~ 21151 261 I -~-------bull---__ _~~_~______l-___--_
1 lhe$ 1111($ I1n (or SlIlIIllltS Stpnnltplr PHrilClld IIrtlrdlng 10 1hr prollIlIlr( OIiIIiIl(o(I on Imgt$ 4 to IC ~tcond nUlI1 hlr r(J)[ltnts stl1ndnnl llrrot of tilt 1I1(1111
1_1l1~ n-J(lri(iot in relli(Upound rpoundsins (lllalIsfs of VIOJII( lixsue b1 the lhomillric lII(lloli
-- ---~--- - __-------- shybull I I I I Varlgttton
_________~___ ~~lu_n_Jl_Q_~~~_____ ______I__~_o~S_J frOID lDean
Percent Percentgt458-1 ~65 +41IWtl-li 130 -a2Hli8c aliO +26S41i8-d bull 130 -32
1(-011 34I10Olifgt __ bullbull __ ~--====
li-9~2n 881) -06 li-9~2-b Si5 o ~HH2middot(middot S i5 -6$-H2middotd 000 +1
8851 054
O i5 +6 9 i5 +6 950 -20 U75 +6
H-liG3o-n bull -1 n-li6~b bull __ _ -IH-IWH +4H-l61511 bull -1
1tmiddottlU
62~-lI __ 62~-b ij24-( bull OH-Ji
(-Ull
I rll(St oluls nre tor separately ~xlrflCled SllllllllCS IlctOrdlug lO procedure outllned ou pages 4 to 10 i Secoud number r~prtgeulS stulldMd error of lIe menn
36 TECHNICAL BULLETIN 920 t ~ DEPT OF A(]RICCLTCRE
ReUUER A~ALYSrS I~ CRCOE-RcuUER PROOCCTS
Sew rapid photometric m(lthod~fol the ddellllinttion of rubber and reii Hi ill uaYllp ti--ut htp lllell pIPHnl pd oil pag( ~l to In A brief H1111111tlY of It similar rnpid llHthod fm 1I1hb~rllnltlysis of u1lulcanizNl tlIldp lubbll pl(Hlmtlt whielt i~ bn-(tldo on the prill o
ciples dehtilcd tlllLe follows Duplltate nt-gm sllmph of the finely cliyiliNl IlInttlitiup wlirllll out [~ei-()l (all hl lIf((tinmiddotjv INd to lt1iyidl till alllpl) TIll kltolll-olubll portion of till )111(11( tlrc di-olved a- indh-Htpd fot thmiddot lllnkill~ of -tlllHlunlluhhll olutiou Oil Pt 1II hut tIl IUlIp Hn lIn l-fplImiddotd 10 lHI-ml rolllllltti( fln-k antil1ltld(lup to Olllll1l The bnlulUp or till JllO(ldllll i- thatutlilllll on paWs -1- 1 IHI Ii 111( 1(111 1- nIP IXPIP--pd nil til IHi or Iw oligiJla w(lullt of I Ill (I11l1p-I1l11Ilt1 1)(0(11(1
Hupitl PlllimiPJojgtiWllllllllh llIltllOd~ fOJ Ihl llPtlmiddotminntion of ImiddotUlJbll tlnd 1(-illo- ill -111111 Illllph of gutlYllll tiUl IIll dl-eli)ed 111() IlltlY d~o Ill nltlI1lld fOl III Iwl Illhlwl- and l~iJlmiddotb(lLiJlg plant TIllt l[Olllhup hns nlo b(l1l ntuptpl fot IIH lltlIll1illtltioll of lllhbpl ill 11lHhrublwl Pl(Jdlld~ HIIl 1111 hI ndaptld JoJ IIll ann lysis of ynt1J(gt( ic lllbbl[- The llllthmb HIP 1gtn(11 fill tIll fol1owill plimiph- III Grinding
tIll PIOPlly driPl t i~lIl 01 Ul tillg tIll pnHhHt to tll l((lllilllllh~lel of filWlH-- til plllllit qIHlIllilnth( lXIIHtioll 01 IIlbhlI 01 1(--IJl- () llsing oXWllutld olnuh (kttoJls IIt(talp and() fllltil for LIbbel and IH(ltIlIlyptIJllIllIoolYlnJld-o flJllh 101 niJlsl with t(lathelr high IlPililig points 111 to n C) l]olle or in mixt tIll thllt Pll mit tlll rnphllxututioll of luhll(l OJ [middot(ill ill ~() to (l mi1lutp It r(latiwly high 1lllIllllltlltP Ill to 1~11 ) l) lllllipitntillu till luhblI OL Imiddot(ill frolll aliquot () f till oltn ion I IlIlllI-i () f Hlltabhmiddot pl(~(i]litallt (willifhmiddotd lthmwl fOl IIlhlHI Hild llitlifild lllr fOJ JP-illl t~) IIlHkillphotollllliilPIIIIiIlof PlllPlltal of liht tLaIlS mittUl(P lIftlI IlIlbll (II Il in PIlipitalioll 11 II WI( Iplllh thnt (limiJlall till PIIOl dill 10 xtralllOlh (0101 (till dptl1minntinll Iph jill 011 tIll dtwlopllIlJIl of H HIli rOI1ll tlllbidity 111 hpl than I (olot rI
jJlIlpOP-ofallnlyi-I ( p(lllil1thb IIllijOI1ll turbidity or 1llt[lIinmiddotd d(ltl of jgtIp(ii(JlI l)~ lIltlkillU tIl plllltollllmiddottri( ntdillU al tandinu tiJlH~ (dlllilll wlli(h IhlllH(lill-- IP 1llutinmiddotly tnhll) t1ll1t an hlsl~1 oil the (oJlItlIlllItion of IIlhlHI Ill I(ill (lIPIipitat((L
TIll -I(p ill till jll()(Plhul HIP 1-- follOylt (1) 1l~UIIL uJ1lplls of thwl UJfJlllHl (II tliddl(l HUt dlipd 11Illtplial an lXIllltel with11 Ill of till nlnll ill t (oU tlllltIPlll[gtPImiddotatlup oil Iath at 11 Cbull fol 11 minutl I) iIP1lIin(middot(lohd til( (XUtllhllll Jltldl lip to It middotml ynlmlll til( (nlifild by (Illlifllgiuu HlId thlPl IlI nliql1ot of tIl (IalioPlllxUlltl nll Uillltlmiddotll(t to l-llll OIlIIlIllril fiuk- (1) For a trial Ilnditlg 0111 III tlll j liJmiddot~t IllHII IIjI to Ohlllll with lilt Pll shy(ilitnnl a 1(11 it 111 (Dod fill llli lIut ( ptotoJIIltlil IPtlllillg-- of pllllntnl or liuht tlUtllIlillal(I oil n (lpel OphotnJlllllI at rase hng-tlt (If 11 llJ Ill Ol It lollllil1lPtImiddott lloyidld with tIll P10]11 I 1110110shy
Ihlolllltt hmiddot Ii1llI Olllhi lIatioll for -1IpItillg UJlproXilll1l tply Wtl P ]Plwth )0 mp are HHlltk TIll Illldillg lliJtaillld fol tIlt 4-milutl tliall(~ll-
bull
bull
bull
RAPID PHOTO~IETRIC DETERIINATIOX OF R(BBER AXD RESINS 37
ing are referred to a table of equhmiddottllut~ previously p1(pa1elt1 on the
bull basis of 4-minute reac1inJ~ for tilE nmge of lot1telltlatiol1- of rubber or resins to bE elHOlll1t(led tmd gidn thtmiddot -tnnlillfr tillIP fill rUbbEt or resins aiter prE(ipitlltiol1 lwfolE photoIllNliI j(tltlill1 un IUade The r(middotnmining dllplllatt aliquot lll then HHllil up te ol1l1Jle and lpoundadillg ale marle ut the -tandillfr tiUlE iudklltll ill rhl tall1lmiddot for the final r(adillg~ -1) 111( milli1lnm or p(tCPlltllt- of lllhbpL (II 1(-in pr(s(nt are rpadholU a prlpan(l table of lquiltlput for tlll photoshymetric readings h1~l(l ill pnell e1-E on pxpPlilmlItal lhln 1111(1 u-ing as stimtlltlds pure luhbll in 1l1bbtl milllYb aIHI guaYllh ll-ill- lxIHlatt~ in resins detNIl1111lttion I
LlTERATlRE CLTED
(1) lUnSbull 1fl36 THE mURMIXTIOS IIF IOTA RE I III OOl THER llT~II
F1 bullrol IlY U(T1l0fll UfSlfi ~rrnrl r flm lt1 KEYS TI Bill Chern 114 44J-l59 illns
t1 ~ICPHHlObullbull T 1J3bull~ lUTHOO roa THE PtRInCAnu Or a(lIUl IRrIlHU It of TIn
PLRIHEU Htllllflt [ i Bill lallllall 111 Rmiddot 711middotj iIlus
I ) RHBERG P B Ul5 A METHIlO Or ~u(ronrll-nl Hi tIII rUIl[1 f71 ii illlI
bull 14 Hoss W flbull and HARDESTY J O
llH IR1ltDII Of HfITilIZfmiddotR DllIJS ltt 1 Yl fll Off gI bern JIIIlI i ~middotmiddotlf IIl
101 SPEltCE D nnd CuoWELr ~I L 1933 DETER~n-ATIOo OF RtBBER Ii nrllllpoundRBfR Iusr 1uI II1 amI
Em~ifl cttIliIa~~ r Ell i 71middot7i l11 (HI WALTER E D
1U44 ISO~nlS OF PRTlltSrr 1trHpoundV bull l UI n W lHHt (Tnmiddot 1ETS FROM GiYI l~iIl lItr Clttrn SII J UI titJ middotn9--C1 ilIu
17 J YOEbullbullr H lO~( roLORIlETRT 771 IPmiddot nl -W Yurk f H Plrwptric hmica
naly-II rimttry lUll XphHHlnmiddot~ y 1 1
11
HI) ~ fPHELolzTRf 57 111bull Lin xw Yk t H lt PhmeHt CblUlmiddot ila AnaiY~l~-(H lithrry and XIhmiddotILpfIY Y wirh enomiddot rrJlllrjr hy H KtlJnJU11 I
t~1I --- and ~ARVER L 1f41 nlua-w ~in L liLhr IS IP ll~ XIW Yrk
bull For-sale by th~ ~a~fr1nt~nf1ent Dt~c~~ogtnts-~ s t1i rArnn~ut Pn~~~ tJffieshy
Washington 5 D C bull Pl lU ~nts
bull
bull
bull
RAPID PHOTOMElRIC DElERMINAlIOX OF RUBBER AND RESINS 11
The mixture is tllll1sterled to It 100-ml yolumetlic flask with sevtlul washings of hot solvent cooled to n s(uHluld telllpelatUle and madtmiddot up to volume with the saIne solwlli SlwtiaJ IHl(uutioll mllst be takell in transferring t)( lubbCl solutioll to till YolulIHtrie flask so thnt llO rubber is lost It is cOllytllielit to illSllt It j-ill(h funnel in the ne(k of th(~ voiumptic flask to pOll tll( lubb(ll solut ion ill OIl( OLWlHtion into the tube of tht IUlll1ll with Ihl aid of tIl( glllss Iod nlld 10 follow illlshyl1eilintely with S(gtllnl ~Ynshings of hot S() I(111 whkh lIl lilst pouled 1nto tIll btll PI 1I(ld dIIleUy OW) till 1unn1 aId IhpII t1I1uugh Ill( funnel
H time hi not all objllt it is uls() flasible 10 p1alt Ihp linely diided particles of Iubblt ill tl( flask toJ1tuining Ihl sohPIlI 11(1 allo it 10 stand until til( 1lIbbpI is dissolYld TIl( llIblJll ioluliol)s alp slolpd in Ihe tightly s(ojlP(1(d OIUllwt lit f1nks in a ((lol dark placl Thel they willltIIlUlIl (OlUilallt ill Idut 101 an indlfinit( JlPIiod
Two ellliblHliol1 (IlP~ flIP IIltl(l(-OIl( 101 o~ gill of tisHlIP (ollin illshyhw 0] to 10 PII((Il of rubb(I ((1lt)middot1 to U mg of IlIbb(Iill tt ~)-1Il1 yo1ullll) and th(middot otlHl for ()~ gil) of tisslIp (ollaining 10 10 ~l() peLshycent of lublJPl (O to 10 Illg of lulllJpI ill a ~)-))Jl YOIlII1IP)
(Hns HlJ 111 TO 1 II~IWEX( (II BIIII1EH
III oldl) to ll(llllP (ITOI (0 II Iltinil1lIl1l a lIitahl( lllillobllllltp is lIs((lo Jl((lpn (P IhI ~lt of stal1da Id solut iOlls 0 f a Ii ng (OJllllllllll ious ill til(gt (III)(r( Ol 10 1 gt(I((lIt of LubbI In (11( PI(sPIII WOlk th( 1111shypIoypd HlhlHIg mic)obm(ltp Il bullJ) whkh lIi(IlJalpl dlli(I~ 10 0001 1111 was Toulld sntisiadOlY F(OIll n lll-pltIllllt -talHlulIlllbwl solushytion in HSlIitnbh solnnl lt[lIiIlIUJl1iiat( aliqll()l~or n) Ol o~ n and ()t 1111 al(lllla~UIpd (Jilt ut n stalldUld ~Olllli(lll tlIlIJl(1atulp (~) C ill wlitllmiddots labolulol) I IlIIHIl-of II lllillOillIl(tlt illio ~l-lld yohulI(lie f1nks ploid(d it h gla -(OPIllIS gllollgh of 11ll lubhpl sol Pili i~ thllI addltl to (tl(lt flask to IlIak(1 l 1111 Ill1I IUI(middotc (0 t hl all)ollllt of lllbOPI solutioll ]ll(yiously nd(lpdbullflll DI ntl 01 JlImiddototlmiddottli lolloid solu tillil Iras h(PIl Hddld lIP (bhpl is JlI((i pi III tpd IIlld SP(middot(t )opl)()tolllshyd(gt( 01 (jIOlilllltp) IPallil) an IllHdp 1I((OIdillg to 11ll JlI()(pduJ( Oil shylitwd Oil pagp 1middot1 Th( 1(ldillg~ 101 palmiddotll (OI1((III)Hlioll alp 1I(Iaglt1 anel plotttd Hgaillsl t( ntilligllIlll of 11))1 hI n ~)-1ll1 (jIIlIlH 0) [gt(lClntagl of nlbblI (nltuln(pt 011 tw bnis of tl2-glll lilsul Slllllp1(gts and aliqilOt olulllt IH(IOI 101 (itl ]1I(J((dlll( out lilll(1 Oil pagl 1middot1 This PI()((lhll( i ((l(alld t win ill (a(1 (11( II slandald llIbbllsolushytion was PI(gtllllpd IIOIlI slpa latll XllH(1 ld 1 a utln)(l lllbblI 1 III pips TlwcOlllpl(tpdtlla alp pol(l (1) (loldilla pap(laslrowl1 ill figulp I
Tbl )llO(p(II I ill lllilking a (Uln rOl I to ~ jiI((lIt of JlIlJh(1 i~ simi1t1I to (hat rOl 1Ill l1IlP ImI1 to 1 JllI(PIII (x((pl ill a f(middot dptnils The quinlu]lli(Htl aliqllols a 1( sput(d Ht (lI 12 a j 0 (78 n alld 10 mg ])(gt1 ~i-1Il1 Yolunl III sNuIing thp 01 Illg pll 2)-Jll1 YUlll))lt til( (gtIO(ltlIII( outlillPcl ill IIIl PIp(tding pnltlgllIph is followpd In the rllngl 1 toj Illg )IN ~)-1I11 OtIIl1I Ilw (lsi 1(lt1 (oJ)(tlllltlliollS of lubbpI alP s(gt(ul(gt(l h IlIPHsuljng alhplOi- with Xnlional BIII(atl of Stnndlld~ tltllsf(I pip(Ws flOIl) tltl OI-PlIl(1l1 lII))ll sol III ion
12 TECHNICAL BULLETIN 920 U S DEP1 OIr AGRICULTUHE
RUBBER IN 25-ML VOLUME(MGl
100 1~__middotOT5___ITO___15__2~O=--_bull 2r5_---= bull 3rO__~-_40 bull99
98 shy(I) CI Z
~ 97 ItJ II
~ 96a f-IIJ
e95 o l
94
93
92 ~__~__~__~____L-__~__-L__~L-__~__-L__~
o 1 2 3 4 5 6 7 8 9 10 RUBBER (PERCENT) bull
FIGURE 4-Cnllbrntioll curve for rubber in 02 gill of gt1n~ule tissue containing 01 to 10 p(rcpnt 0 lllbhlI (nlnllillg~ (Ill 1111 J~pl~ll llhooplf(middotttmiddotlc colorimeter with 720middotmu filter und amiddotml uperture the 01 divisions required in actual pracmiddot tice for photometric IclHlings arc olllittltd)
Similarly hl the range 5 to JO mg pel 25-ml Yolume the desired conshycentrations of rnbber urc measured from the O2-pllmiddotcellt solution The complete data lire plotted on semilogtllmiddotithmic pttpel as shown in figure 5 A
STANDARDlZATJON AGAINSL G1IA111 ETlIIU 11 ETHO()
1he alternate ploee(lule of stt121l1ald izing th~ IneHell~ method ngninst the Spellcc-Cald well method (II) altholl~h flaSI hIe 18 not adVIsable because of the extra work J(quiled ancl the introduction of the expershyimental error of the benzene extraction method
HESINS CALlBllATION CUIlVES
The procedure for constructing cal])lation eUlves for resins ttIlulysis is similar to thtni outlinlltl for lubb(l lxcept that resins exndate of gunyule is lIsed as the resins stundard The resinolls exudate disshysolves very readily in the resins solvents listed in table 1 It may be prepared in two ways for use as a stnndard-the clean exudate as bull gathcrcd from the plants is dried for 6110mB nt 65deg C nt a 30-inch ltcuum or the oXllllate is dissolved ill acetone and filtered In drying
bull
bull
bull
RAPID PHOfOMElRIC DJllImlMINAlION OF RUB BEn AND HESINS 13
RUBBER IN 25-MLVOLUME(MG) 2 3 4 5 6 7 8 9 10
r~
eo en ()
90
f--70z Q ~ 60ltl LIJ a ~ a LIJ 40 E 0
0 50
~ 0 ~ I 30 0 ~
A 20 I I
o 25 50 75 100 125 150 175 200 225 250 RU88ER(PERCENT)
RESINS IN 25-MLVOLLIME (MG) 2 3 4 5 6 7 8 9 10
1--90
80
en () 70
I z Q 60ltl LIJ a
50 0
a ~ LIJ 40 E 0 0 ~ I 30 0
B ~I20 o 25 50 75 100 125 150 175 200 225 250
RESINS (PERCENT)
lJIGunE u-Cnlibrutioll cUve for (il) rubhcr in 02 gill of gllnn11c tisme conshytainingl to 2G perc(lt of 11IUU(Il I1na (1]) rpSillS in 02 gill of glI1~l1ll~ tissue (ontnining l to 20 nelecnt oC l(sin8 (U(ndings Oil 1111 E(lI~1I llhotollectlit colorlmeter with 720-mtL filtcr and O-ntJ aperture the lO divisions llquired In uctnul prllctlce for pitotoulPtlie PllllillgS tlre omitted)
in vncuo arelntivply HllHlll qUllntity of (xutlnte is plllcel] in a lalge dish since the mass rOHmS nt the beginning of the drying process Pracshytically ull of the ne(tone is evnpollltpd olf oyer a steam Ol WItter bath and the residue is dli((l pnlYllized in It mortnr and preserved by
14 lECHNLCAL BULLErrN H20 U S DEPl OF AGRICULTURE
drying as indicated for fresh exudate In all ClSeS the products are stored in airtight containers in a dark coul place
The usualllnge of resins from gunyule tissue is about 2 to S percent on a dry-weight basis For work with this plaut therefore on1~ one curve is needed A typiCallesins ealibrntion CUlTe is shown in figure 5B
PnocEDuuE J~OH RUBBER ANALYSIS
Duplicate lXiLllCtiOllS arc made for each tissue analyzed and duplishycate photometric readings are made for each cxtmctioll the final value therefore reportcdreprescnt- nn avcragc based on the four phoshytometric readings
Thoroughly mixed O2-gm samples of the finely ground tissue are weighcd for analysis on the basis of l11oistUlc-frec tissllc The samples arc weighed to an accuracy of 02 mg Oil an analytical balance The method of deriying factors for making eOllections for moisture in samples has been thtailed on page
The weighed samples arc trallsien(c1 to the 2-m1 volumetlic flasks with the aid of l-inch glass funnels and 20 m1 of methyl isobutyl ketone is added to each flask The contents in the Hasks are heated m a constant-temperature oil bath at 115 0 C for 30 minutes uncleI a yentilated hood rhe flasks are removed and any adhering oil on the outside is wiped off with Kleenex 01 H similal cellulose tissue the C011shytents of the flasks am cooled to a standard tempellltule (25 0 in the writers laboratory) in a constant-tempelutllre ater bath provided with a motor stirrer if available and made up to volume with the solvent After the contents are mixed the flasks are allowed to stand for a few minutes until most of the insoluble residue settlcs to the botshytom The extracts are then carefully poured into JO-m1 heavy-duty centrifuge ulJls so as to include as little as possible of the settled insolushyble residue The centrifuge tubes are stoppered with cork stoppers and the liquid is clalifiecl by centrifuging for 10 minutes at 2000 revoshylutions pCI minute The clarified lIquid is poured into 25-m1 volushyl1Ietric flasks plOicled with ground stoppers It i impoJtant to pour off the clalificd (dlart in lWIt a lUlllie that the ill8ol11ble cNi(hwis not Sti1((Z1tp A 1-in(h funllel is plncCd in the neck of the volumetric flask A filter stick (fig 2 D) is inserted in the centrifuge tube through he liquid so that tlH enlnlged palt of the gtiek seals off the insoluble residue and a small portion of the exmet in the cone point 1Vith the index finger the stem of the filtel stick is thell held against the side of the tube towllnl the analyst who holds the tube with the thulllb rmtl t11illt1 fingCl The txtlHct is thell poured off easily into the yohunetlic flask without distnrbing the insoluble residne The COllshytents of the Hasks are then ))ollght to the standard tel11pelatme in the constant-tempentl111e wnter hath
The reagent blank us(d wit h the spectropllOtoll1lter 01 (olorimeter ig prepared as follogtvs ) 1111 of methyl isobutyl ketone 01 other solvent used is pipetted into It 25-m1 yolumetric fiask and 01 ml of protective colloid solution for rubber is added the mixtule is made IIp to olume with acidified Oil-pelcent ethnnol and mixed again the rcquired vo]shylime of the mixture is poured into a cuy(tte or an absorption test tube
From each plir of tissue extractions to 5-1lll aliquots 01 the clarishyfied extlact at the stnndanl tempCraLule ale pipcUed into 2ii-m1 volushy
bull
bull
bull
bull
bull
bull
RAPID P1IOTOMElRIC DETERMINATION Ol~ RUBBEH AND RESINS 15
metric flasks and 01 m1 of protective colloid solution for rubber is added to each One additional5-mL aliquot from each pair of extracshytions is similarly prepared to serve as a key to the standing times for the final readings as indicated in table 2 These additional aliquots are first made up to volume with the precipitant acidified Do-percent ethanol mixed by carefully inverting the flask three or four times] and allowed to stand for 4-minute periods before the reading is made on the colorimeter Vith these preliminary rendings a~ a basis the standing times for final readings are taken from table 2 For example if the colorimeter reading in rubber analysis at 4 minutes is 655 then the standing time is 15 minutes
The two rell1Lining duplicate aliquots for eath extraction are then made up to volume with acidified D5-percent ethanol mixed by careshyfuIly inverting the flask three or four times nnd allowed to stand for the required number of minutes as established by the preliminary 4-minute trial readings (table 2) before the final colorimeter readings are made on the contents of the flasks
TADLE 2-St(llllliIlU time for variolls (OllccntratioIlS Of rubbcr or rcsins aftcl iJleaipitation bcforc colorimetric readings mc macle
[5middotml aliquots of rubber in methyl isobutyl ketone or of rcsill~ in ncetonylncetonemiddotcellosol e 3middoti both made up to a 25middotml volume with pr~cipitantj readings on lvolyn photoGlectric colorimeter with i20middotml (690to iiOmiddotD11) filter and Umiddotml aperture]
RUDDER I
Range of colorimeter Approxima(e S~nuling i Rnnge of colorimeter Approximn(e Standingtrial readings after 4middot range in conmiddot tJIIIG for trini r(adings nfter 4 range in con tifillnlOalcor minute stunding time tcnt In tiSSU(l Unnl I t I t (rending IIlIDU C stum Illg lOW _ tent III Issue reading
Percent Villlits II Perfe~lt Jfinul 955-999 bullbullbull bullbullbullbull 09-01 00 01-03S bullbull ~ _bullbullbullbull_ Jl-O9 10 743-954 bullbullbull ~ bullbullbullbull __ _ 43-10 30 1420-550 bull ~ ~ 137-94 5 6_3_9-_74_2__bullbull_ bullbull bullbullbullbullbullbullbull_-_---- 6__8-_4_4---___ bull ~ ~ bullbull ____ MQrcthan 13ibullbull_-~_ _ ____ 15_~elow t~ 2
RESINS -----------------------------~--------
957-999bullbullbullbull ~ 139-01 60 11419-amp11bullbullbull _bullbullbullbullbull ~~ 13~5-939 10729-956bullbullbullbullbull_ Ii 25-1 middotJO 30 ~gtl2-40(L bullbullbullbullbullbullbullbullbullbullbullbullbull _ 2025-1320 5 595-728~~~ bullbullbullbull 8 as-G 20 20 IBelow 292 bullbullbullbullbullbullbullbull- More thun542-591 _bull ~ bullbullbull_bullbull_bullbullbull 038-039 15 2025 3
I Precipitated with O5middotplrccnt HSO in 05middotpercent ethanol When the npproxilllull concentrntion of rubber or rcsins in solution is not known trinl colorimeter rend
ings atmiddotJ minutes s(nnding till nrc mndelS n guide to the required finnl standing time indicated in the last column III prncticc UII cxtrn nliquot is prcpnred for precipitation and thIs is discarded after the trial reading is mnde
3 lrccipitnicd with OmiddotpcrccntlhSO ill HO
PnOCEDunE I-On UESIliS ANALYSIS
The procedure fol resins unulysis is the same as that indicitted for lubber analysis eomiddot(I]lt that f he -olyent js acetonylacetone-cellosolve ~)-7 tht precipitant js O5-perctnt H~SOI in H 2 0 and 01 1111 of the protective colloid solution for nsins is added to each 25-m1 flask conshytaining the aljquot of the extract before the precipitant is added
PnOlmmlHlC INSlHu~mNTs UECoIUlENDED AND CALCl]IAlION
OF UESurlS
Photometric readings of percentage of light transmittance (T) ale made on the Coltnum double monochromator spectrophotometer at
16 lECHNICAL BULLElIN 920) U S DEPT OF AGHICULlUHE
750-111 wave length or renclings n1( mnde on a colorimeter pLoic1eri with the monochromatic filter eOIl)Il1l1tioJl for sllecting the npploxishymate wfLYe ]cngth at 750 1Il~ For routine deterlllinations the Evelyn photoelectric colorinwt(r ployided with aTW-lllJ filteL is IC(0l1111HIHtll
The liquid in hich the preeipitnted lubber uld rcins are susshypended is pOll(d very cHrdully down the ill~idl of th( clette o absorption tube to lLYoilllllC fOLll1ntioll of ail bllbblls Aft( LUbbet find resins preeipitation wlwn the EnLynpho(otkcllie (olo1imetll is used the readings are nmde nft(L thl standing tillll- hOWll in table~ It has been foulld (OIlllliellt to 11lPtipilatl tublwr 01 llsiIlS from the aliquo(s at ~-millute illtlLvals This allows stlilieipnt tillle to check the eOlolimet(r and to makc 111( lNHlings Vlwll a ehangp is IlltHk fLom onc rending 10 the l1lxt it is advisablp 10 llle the clIvctte 01 absorption tube nt lpast twkp with slllall p(Iltion- of the llllltiol to be leitd
After the colorimd(L lluding lta e becll Iltndp till IlIl II igllIlllS of lubbel or resins or thc lpL(el1hlges pnslnt in Ihe aliqllot are r(u1 from cal ibmti(Hl (urVlS (fig~ 4 and raquo or from plepn Led tables of eqllivallBts baecl ill each (liSP on (x[lerimPlltnl data The results are expressed as percentages of dry weight (S hours drying nt 100deg 0) of the original tissue The errol lltle to lCflyjng the insoluble residtH in tbe voltlllletLie pxtLHclioll flflsk wlwn the pxtrnetis being mnde up to YOlllmC is V(ly slight sinlte only (U gm of tissue is used FOLroutine allalyscs lhis ery slight eLlor mny be dislpgnltec1
EXPERIMENTAL RESULTS
The experilllCnlal reslllts Oil hi(lthp method- of tU)lPI and l(sins analysis a le based ttl( d icussld blicfly hlrehl
PHEPMINrlON OF SAlULES
No difliclllty was expPtitI1(ed in pltparing slmplls of llllrscly-glOrt guayule plants 1pss thnn ~ YPH1S old 101 rllbbpl alld IPSills analysis In the cnl of Odll filld-gl()n gllayull plants PIIOtS hopel mtty be introdmp(l by the custOlllalY Jlwrhod 01 pICpalillg Ihp sampl(s 101
HlutlYHis as is lwipfly i n( ita ttd ill th is s((tion Smh enOlS do llot nffCct the ])lCcisioll O[ t1H llwt hotls for LllbbtL n nd Il~in~ nnn I sis i nee till) are due solely to tIl( tbsup--ampling (llo(pdule in thi (a~e of oldeL field-grown plall TIll 1lllt1lOcl of salllplill7 fipld-gl()l1 plants JllOLC than ~ Y(HrS old thenfort Ieqlliles iurtlHl jnttigntioll
lgtAHnOILr~G FOR HEllOVAL OF UUVLgtS
Parboiling which (onisls in boiling gllltyule plants in water [OJ
8 to 1~ ~ninll(s ~s col1llllonl) uSNl a~ n llHans of Itlli rCnl()y~l prior to drymg nnd gllnllng It I~ tHI([())P ll(e~Sllr to ltItLeLnunc all possiblt~ eflct oi tlti PLOtPlllll( )ll (Il( final results Exp(liments have sh(nm that (helt i- fl Flight loss ill til tmiddotjght of lOO(S and 4(ll1S In I typi(ul lXpelillltll hlu1llHs of ~- ii) -1-ytII-old gllllll( pllllb were Italnd at randolll Olll ( of talns wa- paLllOil((1 and the le~es (1( haIHI-pi(kpd [lom till o( hpJ Ht Both pis (1( dlipd for 48 hOttlS at (i) C in a llI((lwlli(al (011((( ion Oyell Th( lpsult are SUI11111I11izNI itS follows
bull
bull
bull
bull
bull
bull
RAPID PHOTOMETRIC DETERMI~ATIO~ OF IfCBBER A~D HESI~S 17
Dry ucilht lust ill lariOilillf
Plaut (pcrcrllO 1 1 -I2 ___________________ _
213 _____bull _____ bull __ _______ ___ ____________ 12 2(
pound(111_ ______________ 1 R
4_______________ _______________ __ _____
A __ bull __ -_
The efred of parboiling on till final lllalp i SUllllllatmiddoti7(middotd ill figmc G Rubb(1 lecoYelY w(t about 1 percent higher for parigtoillltl plants and lEsills re(ovelY somewhat o-er 1 i)(lr(lllt 10Wlr The (Ii tference in lublH-l r((o-elY cannot be ae(01111tltlt1 fot by loss in dry weight _ due is to be found in a study of thE grinding lwhadol of a parboiled and an unpnrboilEcl shrub The grinding of the patboiled shlub in the hnml111 mill is much fadlitated and ns a rule for tissue with a rubber contCnt below 10 peteent llO aggregates of rubber deelop in the 1Il11ehinr during the (Jpelatioll Yitll the unpnrboilNl shrub some dillictdty may 1)( (lxppliellrl(l Sill(( sOllle of till sti(ky ltxlldutl Oil the plant may scI( u nlldei for the fmllHltioll of lublH1 ngglPgates Til is apparently explnins the npparlllt los in ruhbpl frol1l the llnpariJoiled hrllb as eompnlelt1 with thl palboilld (fig (i) TI1(loss in r(sins
II
RUBBER
10 f-
Ishyz LIJ 0 0 LIJ 0
9 --RUBBER -shy-------shy
-- RES INS -shy---shy-----_
IJ) 8 I--Z IJ)
LIJ 0
0 7 f- RES I NS -0 -shy0 LIJ III III J 6 f shy0
LEAVES REMOVED BY PAFltBOILING
5 f shy -shy - BY HAND PICKING
4 I I I 35 30 25 20
SCREENS (SIZE OF OPENINGS IN MM)
FIGlRE Ii EtIe(t IIf pnlticlp sizE Oil lEcorPQ- of rubber lind (iiil1s when lEgttiye wEre remond hr Pl1liloiling lind h~ hand pi(king ((Dlltrol) plllllt1lt groUlld in t hammer mill
6114038-46-3
18 TECHNICAL BULLETIN 920 U S DEPT OF AGRICULTURE
recowry from pUboil(d shrub may be due to the loss of the resinous exnc1ate during parboiling This exudate forms ns It SClim on top of tlw )iquol in the tank
On the basis of t1wse results the recommendation is made not to yaly the nwthoC of leaf lemoYal in any 011( lNi(lu(h project Then fltirly compalabh IcmLts should he obUiined
70 ~------------------------------------------~ LEAVES REMOVED
BY PAR80lLING ____ BY HAND PICKING
60
-I-Z 1amp1 0 50 a 1amp1 a
en 1amp1 gt1amp1
40en gt-CD Q 1amp1 Z
I shy 1amp1 30 a l shyx C)
1amp1 ~ J 20 I shy 0 I shy
10
O+--L__L-~__L-~~--~~~~~ o 10 20 40 60 80 100
NATIONAL BUREAU OF STANDARDS SIEVES (MESH)
FlGntE T-lJiMlil)utiun of l1Ultkh si~(s of gnll~II( tiSSU( JrIOllll(l in a Ball amp 1ew(1 mill to pass six dllIerNlt S(I(euroII 1(IlYes Iemoved from plants by palmiddot boiling 11(1 hand picking ((olltloll dpfo1iatld plants dried to 1I lUoistufl l0I1t~nt (If 01 to o) 1)(ICl1It ground tiSSlli IbalH1 1() minutes ill II ~i$hel
bull
bull
bull Kahn shuk(f
RAPID PROTOMETRIC DETER~UXATIOX OF RrBBER AXD RESIX-i 19
GHl~DIgtiG
bull Th~ entire pant 01 plant l)iHt a~(gt fl r(ll it pllllIIirU1ry lSillg fur J hours ntGi~ C prIOr tD t 1( plChmll1atmiddot rLlmhll III a II lItmiddot or n Ball amp Jewell mill ~n llltllysis of paldch lzP- nftl~l (oar-( IIindill shows that tlwy ar( about tIlt llllH fOl parbojlP(t awl IJllllluhoileu hrubs I fir 7)
The coalilly gloUllll ample i-- thPll Ildlll forI toUtmiddot at ni C afnr which it ha lllilobtllL(gt output of ~ llllut lII hmiddot- dptPlIIlilwltl by drying submlllpil- at 1110 fot hOtll- TIll 1 IIIIll i lltllt lmiddot0l111d hi a IluninHl mill TIll mo(lel uP(t in thi IIIk i 1I Hu IIIOilll mill as IllUllifill bv Hoss nnt Hartlet ( 1 -[1lt111- with n1ll1l1 pldushyrations ittI lilnbhell b rill HanlIolll V0ll11nHiol1 ElIillllmiddotrill (0 The size lutllihl11 iUlJnole So I ( 111m t ~ II t HUIII Xl) ~ I L~ 111m nnd So 4 lillllU1 11 ttllilhmiddotj 0 r tllP Imiddotlult~ p(lln-It willI t11(e Sll((IIiZtS with )arl)Oiltll awl uil)Jtllboiltd hrlll b lOwl1 in fif1l1fmiddot-- This hows t tnt 1middottttIl ~(I 1 llllll (Up jlllilnl IHlt that
r------~-------r--- ~ --r IHAMMER-MILL SCREEN
O~ NO1
NO2 ---shy U NO 3 ---II
I
bull lL
z
r ------ l 30 ~ gt III
i I Imiddot
i ~ I
I 1 I I
~ 20 I - 1 iii 1[ r 10 ~ ~ ~ I _ ~ I r A bullbull
o bull L-~__~__~~__- ~~ 20 40 60 80 100 40 60 80 100 200
NATIONAL BUREAU OF STANDARDS SIEVES (MESH 1
Yutln I i-tlillltiuli Hf pur id lZt f ~naY1l1 t middotnt r1 lI1 i ~ a hatlltlllI 1IIi11 to 1111 Lx IHtllllH middotIn Lt-anmiddot tIlllunl loy la1 litkh~ omrl t 1) tHul parbuih~ -t B ~ thmiddotfuliufptl ]~lahr thpt tu tt fit t 1 It+gtr-tt1 Jnui~tHn eunttlIt _~rnlitl tl~UP ltakmiddot~~ 10 UddU it~ 1 rtmiddot4~pt~middotK1~r ttakt-middot
bull So 1 gingt- 11 tt-liuin-Iy ltr~pl [lPlItl1tat of iilll 11animiddotImiddot- Eqltrimiddot tIlllll hnnmiddot llOWIl dutr fll llltldllllUU xtlutioH 11pound lnhbll lIl lP-ill frolll IolUlIl ~tlaYlllt tl-IlP by dlt IJwtmiddotlUlmiddot lItlilwd oil Ill 14 - 01
i-mllt 11111- -lwltld hi INd I li~ Ii I TIll lllhtIlttj of Itiu~ So 1 (lltll j thnt 11middotmiddot01middot lttwmiddot to amplil tltt Iollllli tilt art lpdnn ib
IntIIll ll~ i po--ihJI with tI lLllit Ilfltl[lll1t It honld l Plllplw izmiddotl rImt ilt tht h of -allllhmiddot with l lllblPl
~ontlnt of ill PPltllt til lIilll it i tlllt pll--ihl 10 11-middot t(1i Xli L
20 TECHNICAL BULLETIN 920 U S DEPT OF AGRICULlURE
Even with screcn No 2 difficult due to rnbbel tlcrltreCtlltiollS may be ob tl
encountered In thes~ caHeH it iH lWit to parboil the shlub fOL leaf lemonll and finally to dry to about 1 to ~ P(l((llt of tnoiibl1(l pound01 b(~t results jn ~rindillp in tlH hanmHl mill
It iH aclvlsable to provic1l thc hammer mill with a ground wire Hillel the presence of static electric (harges 011 tll(middot partkhH will ealls( Home of these to atlhelc to the inside of tllP (olltailWr OJ lila eallsc OI1l( of till pULticl( to form ngg1(llatls EIIolin lalllpling fl01l1 fhis SOI1I(I mlly be (onsi(h1llbl(middot
A1I10l1g the Holnllts with high boiling point that lIlay Ill IlHld in rubber anal)Hs I1IP Illllhyl n-alllyl ketolle methyl ioblltvl kptOIH diisobutyl (tOIH blltyl tHptate llethyl amyl 1Ittail (middotthyl(middotlllmiddot gly(ol diethvl (middotther and n-bntyl (middotthel (labl( 1) TIHse al( also I(sin 01shy
middotent but th( 1(~illS n1( held ill olution by the rll1)bpl pl(l(ipitant tthanol wll(1 lllbb(r is 1)J(lipitatNI (S(ll tabl(s alldmiddotl) On tIle basishyof the lxpHilllPlltH tll( btsf nil-round lolPlli -rol lS in 111( PIlHPllt method is lt1iisobutyl kPtonc wld(h was not IIltlllllfaltllllmiddotd ltIlling Vodd Yflr n A suitable Sl1lgtstit ute iH llHthyl jolllltyL htolt whi(h is l(porhd as llolltoxit UJ)
Clllos()IY(~ (ethykn( glYlol monopthyl (tIH1) blltyl earlgtitol (di(thyl(ll( gly(ol llIollobutyl (ti1(r)~ and acttonylacetOll( may be used as resins sohrCllts (table ] )
In the earlipr work with (sills analysis cpllosoly( alolle was selcmiddotet(d as a suitable solycnt Aitholllh (ell()~oh( alone is pxc(lllnt its rplllshytiwly gwatlL iscosity 1(I(b to bubbl( formation nft(I (SillS pr((ipi tatioll Thi- increased thp (xperimentnl (LTOI OIl of tltp othll I(sins solpnts tI((tollyla((tolH has the proppry of glpatly lNlulingshydH(OSity 11(11 altld(( 10 othr liquids This sohpnt tlHIeforl wa addp( to ((Uosoh( in slIflici(lJlt tlllIonnl to OPI(0111e the dinieulty On the basis (li~ex)le1inwllts ~ purts oi~ a(donyla((tOlll to I puts of (elloshysoh-f (bolll by olume) as Splldcmiddot(l Thp 01 hel Hoh(nl listed hutyl clLlbitol at l(llst the t((hnieal-g1lld( ploduct uSNl is appal(ntly not as good as eithe of t1w ot1(r two () a (ombinatioll of tlWSt
The SOlVllIts JOI liSt in tumlyzing artifkial lubbel$ hy tlw pr(senf method appllLently (lcllIHl on th(middot kind of llI))(I lIp-ityl (Jxidt is suitable Ol BUlla fi and hutyllthlI for butyllllbbl Tlwse reagents IlLe technical g1lld( Calboll amp CtllUil1t Ch(lllilai (OIP This Hllbjp(( hilS not bepn (XtpllHl(ly illwtigated by till WIit(I
PIIECIIIIJ-
All tlst fOl Ih( adlqlJalY or till IHllipitullb ll(Ollllllentillllll11Sl bl baset] on the plctisioll of tllP final I(snlts oiJtairwd with the methods The )redpittlllts s(1e((( n HpJ (xtcllsi( (xp(IimPlltatioll all HatiH~ factor (Hee fig Hi 111lt1 tabItmiddot (jH) Ext(IIin tllts llllTild Ollt hanmiddot shown that H Hatil-gtflltlOIy [gtIpeipitallt 101 1lIbblI is (li-p(IT(middotnt HzHO (c p reagent nil POll sp gl U-lmiddotJ) ill li-P(l(Put (tinmol by vohmlP liol (tllayul( Ipl-gtinl 1l)-P~ITImiddotllt H)~o ill Hl) by ollln( ii lL satishyfaeto7-y l)lp(ipitunt A solution of 1 palt of H~~o to 1 part of H~() (1-1) iI2So1 nnd abo yarious int(lIlIPdiat( proportions of tlllse suhshystanCPs giyp fait 1(511It8 but with till inlIptl(l ill [h(gt ratio of H~S01
~
bull
bull
bull
bull
bull
RAPID PHOTQlIEfRIC DETEMIlXATIOX OF HtBJER AXD RESIXS 21
to H 20 the )olutioll becollles somewhat vbcou5 and precautioll Il1Ult be taken to ttvoid bubble formation When it i5 poured into tilt Cllvettes
It should be lloted that both of these precipitants have an ftellleshymmiddottion It was found that when XHjOH was used in the rubber preshycipitant in pInt of H~~O~ the readings were -table l)Ut were not reshyproJutihk The lIl of XuOH in pInel of H 2SO j ran nHittble result as a llth H(HY(Pl WIWll til( li-P(l put lthatgtl in lublltl llnalysis or H~O illlP-ius anal)j wn-i uddint(1 thl eharalteliti(s of till liquid with pleeipitated ruhber or resiu in HI~P(ll-ioll n ren1 on the lpNmiddottroshyphotometel m tololinlPtprfollop(1 it lPgnlal lIlll II~ lxplaiHd on pHgP-I (Sl( figs 11 aIlIIl) Tid made it lloible to outain lEPJOshydlHibll tpnlt nntI (onplt1J1(Jttly till JpqnitPIl tlPgJPP of PJPcljoll
IIWIE(TI 1lt COl~101J)
Jtl thp ItJiPl middotxlwlillltnb hefoJ thtmiddot -1l]YIlIt allll pnmiddotdpitallb had lIptll ptoppJly adjutp(l it l fOllll tIuH till llP or a Ploltiw colloid -wll ltIi1)cJ [ttlJmiddotntl- imlIopl tll lmiddotpro]lIibility of the lPlllt JmUkllly ()Ilt 111 U lput lUlU illlihumiddot tOJllPOlUtl tpHd liglyeol teltlut( - llpanlItly IllmiddotlfP(] to lit til I1m t IHflll lImnnmiddott nftlr tlH filial prOIptlllll WtlP dlvPllill1 tlll 11lIlpfit (If thtmiddot [llltlltin lollohl wa Hot 0 natlv I1l(lhmiddotd III rlumiddot Ia- of tmiddot ill tllmiddottJmillaritlu it b [1 hmiddotjlmiddot til IIpoundgt Ir llH1 It liltr ill-llImiddottiT Ina lll ptlPII by it U( in ruhhfl mmly j 11If dtmiddottail fOJ tltt lllllmtlllll If thl plot pet in nlloid ~llntill tltlmiddotlImiddotmiddotlttlatiflll lIOlllllllhtiPI1 are iPllllll page
liTFHFEHliG COIOf
(hi II tht lllail 11111111111 that had til ill -111111 II urklll) om tlH method fot lublJtt tlIlO1 rpir- nlalv~i in plaut llllpll- wa ttl (lilll~ inare tIte (gt1[01 till to tIll ptP-PlHt f xi [aIWIIII- 111 TIlt amount of (olor varip from lUllIt tn -amp ]pplwHlI nlt rhmiddot lt IIf thE Hl(ltllial tllP part of till plllIt -lI11lhmiddot(l tilt hi-tlllY f tlll plaut mtteshyrial ~ub-lltInent to Itlllmiddotnmiddot-rill lliI 1011middotly OrllPI Inlw
In ruhlwr lrtl-i I Iii 1101 au Itmiddot 1Iplll11l by 111[ I--r ratmiddottilt thE -lllll]t with uptoIw or 1middotmiddotlIll-ol - wIdell [llllol- rlll loillriu nutttel autI thtmiddot lpill- Thi- howmiddotvt n(tnll- til lXtla -11gt1 ilt prlJ~edun) In lP-ill ltluay-i nllHufldy tlW[t j 11 1 1IO(PIlln fill the 11shylImya of hlulophyll Hwl rIlI-r middotIOII IHlttlmiddotJ dlH lUtl~ In plltIH withoUt alo aiftIriL till nmiddot ulttrll
111 pllIbIll1l Wi tilmiddotr hId h It-ImiddottHI tht Pltlpll 1 hlitlt lilt tlw tulllWlli tollImiddot uIwltllIIntut -lltUIhorlllllltll 1111 tIll tlettlllliIttwr IIf t 111 lWlrl-Uamiddot of bdt tl11blLlittUhmiddot r [1 tItmiddot preshyj
lipitatifll 1lJ llllllWI atbull 1iI- in III -1nrmiddottIi fHlttalldh nlrillU~ amount rf middotlorilig lIUlttll Iii lhll of ih lltmiddottllllhottohttt~l l~ol()r infrtl Hm II upd 1 rwmiddot tld~middottilmiddottll PlllItlhi~ f it j proYitiltl with tIll lilP--UlY tU(jlIdlllIlml tIltmiddotmiddot lllklllUIlI
EIECTIol OF 1 [EGTH~
-Ptfmiddott ral tracilull ru~lI gtIll fr 1 nllb t ~xtltd 1 lIlt-th vI iobmy1 ketommiddot lWtl rill [ Ixt lttltt ll UttollylaIiIitt1l11I1t~ ~-I itoiu YtHil)u~ typp of ~IHaylllt f i lItmiddot art hraquoil ill fio1ll1 ~l Th~ lp-nlt fill I11oohl uio[1t ttl willlr til tltN- fur rht IUiXtIUt iwliutll
100
22 TECHNICAL BULLErIN 920 U S DEP1
90 bull eo
I shyz 70LLI 0 a LLI a 60
LLI 0 50 z
a ENTIRE 2-MONTH-OLD PLANTS~ 40 b ROOTS AND BRANCHES OF ~ 3-TO 4-YEAR-OLD PLANTSen z WITH LEAVES REMOVED ex 30 a C CURRENT-SEASON GROWTH OF l- )-TO 4-YEAR-OLD PLANTS
20 WITH LEAVES REMOVED
d LEAVES FROM 3-TO 4-VEAR-OLD PLANTS
10 A
0
a Cd 100
b bull
10
80
I-Z 70LLI 0 a LLI 60a
LLI 0 50 z ex I shy 40 ~ en z ltI 30 a I shy
20
10 B
o~__~__~__~~--~--~--~--~----~--~--~ bull350 400 450 500 550 600 650 700 750 BOO 850
WAVE LENGTH lM~)
FJGcm O-Sll((middotlllll tramaniW1IHl (mrpS f(JI (xlmll 11011 n J1ll of jlta)nle tissur ill n 2--m1 Y011111P of (A) Illrthyl ji1I1J1ltsl krtonp 1111(1 (ll) nt(middottQnyla(umiddot tClIc-C(l1osuln a-i
bull
bull
bull
RAPID PHOTOlIElRIC DETEH-UXATroX OF ntBHEIl AXD HEstxs 23
ThE dula Pl(S(l1t(lltl indi(ntp Ihut 101 Illp ulimls llHthyl liohutyl htOlIl (lxtrHts (lI(I r(dolls of Il1Hxi11111III nigtol]gttioll wiH1I all (is-lIb 11 cOllsic1(]((l n1( blhn(11 wn ( ItIl( Its lIO to () I1It~ nlid Ii to Iii mJL
WhllNIS tlw I(gions of 1middottnL(s( light 1lnlllittamp al(l lgtPlW(PIl wan Ipllgtltsnr) to Ii nllt jW) 1I1JL nlld alio Silllill1l 111l1b (n SI(lIlId 101 nc(ton ]altmiddot(fmiddotollp-(llloolp ~ pxt Ill of 11a 1111 t illl TIl( (1101 du( to lolo ill tlw litlltitl a 1Il1 lullll(I tH lPill- hanmiddot bpllI PI(_ ipitated ma he 1((I1((d to fltI ynbhing poillt II ph( illg OJ illshylmiddotJall(( WIWp balld nhm ()) IIIJ1bullbull[1I111 lxjlPIitllll1b Illln -h()1 that Ih( lIIot uilahl( WHYI lHlIJ fOI 1-1 ill 1l11J1l(I HIH11Pill- illllllrsi i-in till IlPighl)()lllll()(l of ~llIl1lt bull
bull UIlIilHlIy of n typhn] lXPllillllllt to )10 l1iP(tiP ((JIlllo( of (ItOIS dul to lOIOl in 1llblnI Hnd Iill xtnumiddott 11(11 IIIIolp t jUl i p1llelll((l ill tub]lL Till llhlllt- 1tpIO]II Hnd ((llll~()h whit-h UI(I ](]Hllilltl n 1I01lllIhb1 01(111 lxt 11111 IIll 1llll)1 nmtp[in I and )(middotills Tid IIlnkl it poiblp nftlI tlIp uplll1tillll or tlll o1PIl( (0 [niH lip 1Iidl1p~ of lI111 11111(( ill lit ll11l1)[1 (llnlIb nlld Ihll
Sl(ll n ol1lliOI with tllP olnl IJllt illiollt HIl Iltlllll llllI (Ill ltllthpl prpipitnnt j Ihll1 nddld OUI ha a lIilPt lP( of till lIiciPlw of WH( lllIgth 7) lUI- ill llilllillatiu (nnl till tll Ixtll1I101l ()lll~
Tuu tmiddot-Elilll IJl flrldillY 11-1111 lrlllI IjfJI til islII 1 1(1 ([rllt IIIIIJIlIr JiIlIt~ if 1Il( Ihll 111111 k til I III Ilrln I 1Intd tf 11111 JiSf fill I I II I tIII Ilf Iilltl 1f1JlIIillII1f I Till 1[ 1 IId 1 (I (middotIt 11111 (I1I1iI1 1lf1IWtlfJlIIllfflr p middottrllhIJ11 II J III 7IImiddotIa 111 111 lilt jJIp 111 wilTII
t~t tnVIli~ ~nn r kn t~ i tmiddot ~~l Jr 1middotmt ltlTt
HmiddotOtt ~I~ lin t I ~ 1 t~~l ~qrmiddotthtmiddotrtwb
Hult-middottltlru t T Hw ullut rHtt~ r II I ~ PH~lllt
A~tmiddottHHjmiddott~rjd rl ~gtllh 1 tn~th~ ~ ~ middotI lt~ b w bull hmiddotth~ 1i~lIhun 1 Ii tnl Illd1 -11lt1(11i lullI lUI tJl ll~ t1~11n( I Ihan1li flfttIJir Ult I Uuhtltt ahuul l(hmiddottHmiddot~t trv r fti HIt lftbyl tlonhUt)1 k_hIl( 2 m~ fmiddotf tuhlHmiddotr In mlth~ llmiddotlf- 1 t r
t r_~ t j
Arhlitlltd ~llIIDHl NcWitn1 ( Ar-(lt()nc~middotttrrtrt ritJJI~ -Iu nllJtl4-middotr
ACtmiddottflnp fmiddotxtrn( ~ T-P511ftf tn mtmiddotth~ 1 ~difmiddotut~ kdn 2 nltt ulruhhtr in Un-tIl lltbu )J~IYt
rUth(Hl~hltlft HhubU
Illlh(I(t tttUtUt hUbtl til J ~jlitl(J Hilllll trtIIImiddotjtl1ll
(UShl I ~tlO wHllolH rulh r (middot1111$0]( J~rru t t )lthyl 15bullbull1middot1101 klll1l
Ili( UHUicbcul ~((i1rUtl ~ulu1iin 1middot lIUIll Ilti lrllltlllt I Ruhhr llt1thuI r1 -1 Irld
ltlt1111Sh 2 nuz f)rruhl~rm nlith~l tu- h f nt nil~middothgt(H] tlrlftmiddot 9lUtirtl middot1 1
rlcltfl( H(l dnllltml it
(IISllhH~rI( Iultruhtr CII05 1v ltTlft I 2 UI~r ublwr In llldh I hlt~1 11) lgtjdvr(llsl~9rlltmiddot middotlmin ~ I~ gt AIHItilltl no IrttipHallr iI
~ Bbnk 10ol m(thyl i~tmiddotut~i kdHn H 1 m1 j~~ l1rH-t lt~tlfltmiddotn sf n it ll HltlMjftr~nol O2~mlJ ~U~1o-ulp ti~tW -xtra~middotl(lt1 ltt 411 ml bull ie f Ct- kft rt t~ tirattJ middott ill r u l1kn ttJt
in metltl isobutyl kNqnf nn~i mljp ur tmiddotmiddot ~oml ~urr tttl i t w ltJj1JH kt 4t 3 nlank 1 mL((l1t~rthmiddot(middot mI mttr~ ~but a kmiddot tmiddotc d 11 ~ gtli~b~ hifIAft- fl~ lL lnti 149
ml8(dlfilll BO bull 02 gm guayule U$Stl(middot xUlClt-l tf(h tft wI n nmiddotmiddotmiddotlgt 1 lznt on tmiddot ~Jt r~1 ~~u~~ H~ iI~ thT
24 l$CHNlQAL BULLETlN l20l S DJltJPT OF AGHl(CLlOHJltJ
In table a is pl(sentc(l such c1il((t edlt1tIHC showing that thc (0101 Ixtrnetccl from guaYIIle tisslIe wit h II(P(OIl( n nd (pl1oso[yc is cll(div(ly sCIe(nec1 out by the s(lp(tion or wnw length )0 miL Oil t1w SI)((IOshyphotonwtpl This tnb]p all-HI ihos thai thl Juhlwl altl(l((1 (nn IJl quall shytitntivcly 1(I(()(Ipltl in tIlt PI(ilIH( or Ih (o]OIplnwPIials and Illsins and tlmt Iuhb(l WtlS nppnlllltly 1I0t (xtltI(((1 110111 11l glll1I1l lisslIt b~ tlHSP SOhlllts Thls( ((suIts ginmiddot (OliIHillg (idJt(( that t Iw IISI of waYl llngth i)ll 1Il) OIl till SppdTophot OIllltPI ii t hl 1101(1 p(oshy(ellule in photolllliTie IlIlalysis of luhhlI OJ l(sin-
SELEGTIO- OF )IOiOCUHO)IAIIC ItIIm ((1111110
On th( basis of th( IPHIlb shoWIl in tabl(l 1 al hlllpls (1( IIln(lp to SPCtl lC the PIO]Wl 11101lO(lIOl1ln til Ii ltlJ ((lIllIJi nIl ions 10 llIiOlS (oIOlimet(Is 111(gt 7W-Ill~ filtpl flllnhwd 101 til( I1~lI1l photoshyplpct1i( (o]oriJl1ltll fol which Ill( (hlll(IlIiitit~ oj t hl Ilda he light ilUIlBlIIhiSioll (t) elll nn -hO11 ill fig1lle 10 iws satlsfa(lolY IPshysultl 111( iiO-mL HitlI olllhintioll 101 whkh ttp (middotIatinmiddot light tlnnsmission (ullmiddotis a 1-0 showlI ill figllll (I is -nthdnlto1 hut this is not stnlHlnld NtllipmPlli
Up to fhl PlPHllt lIS(middotflll pound11((1 (ulllbinntions jn lltl iOO-I11L Iunge hayc nol bllll SlClIlld 101 lhp Klpt 1-1I1l1I11PISOIl (olOlinwtll bu fnltlwl nttCl1lpti 1( )(illg IlIHd
TJIpound OF ST~lmW AFTEH HIIJ1EII Oil HHSIS rlll~CIIITTI(J
~ considl1ltiol1 of ttp lillll of Inlllling af((1 plpeipital ion of 111gt)(1
01 l(sinSTlOIll ollltionis impoltant J(jl~ thC1HI(Plltngp of light IInIlSshy
11 rshy10 f shy
09 f shy ~750 Mil- DOMINANTI
~ 08 cshy I WAVE LENGTH z
I III III i O7 - I III
~06 - 05 shyw
a
Igti= 04 - 720 Mp DOMINANT ct WAVE LENGTH- ~ 03shy
02 f shy
01 t shy 1)O~~~gt~- J 600 700 800 900
WAVE LENGTH (Mp
bull
bull
bullFIGlRt IO- COJllPIUlItiw ~IW(middottltll tlnIlRlllii-lion (II (IllP( 101 1i11(1 olllhinulloll
with dominllnl Il(lllllgths at 720 and 7iO lUi
bull
bull
bull
HAPlD PHQTQlfE1IUC JjETER~lINATION OF Rnmrm AND HEtiINi 25
mitted (spertrophotoll1eleL lCuding-) Ol light (1 (tClcrl (phOlOshyJluol01l1et(L lcndillg~) i~ StlhjNl to (hangl
]fjt~l1le 11 and l~ show that ill til( (asc ot tJaugtIllitteltllight llJHC th~ (x[llliHlllIlnl (oIHlitiOllS tllpl j lilst n dtlln-e ill Pll~(lltngl or UllllslllittnlH( follrnY(l by It ptJiml of lClntin stability with only sliuht (1111 tHn- a f(Pl a lIt1ll1btJ of minutes The light t UIllllitblllll t l(1 ill(Iln~(s This lIIay IJP llllllJltlli7P(ll1 ffl II ow 1Ilt )( f(( darI oliIII tIIlIlNlIlitt(IIIlfJIIlh (iditilIiid Ilil1 pllIipintnl )uoshyIn Of ( 8inx in (~f1( I~iUII i~ Ild stahl I 11 itlll If 1inl nh prlshyilli(ioll of 11l1d(1 II IJIX f) jllIli II (fJJltfiIIlilty slllMI IIriot 1) IIIPldUnl1i tll(I1I rllltltilJl oj tJi~ Jlt jiot IUN ilUf Jxl1 will tIt( tOWI IItlllilil I 1llIlllblJIol I ill I~11l11111 d ill till ifjuids JjOI scnttplltl light 011 till phololltHJIOIl1lttl till dilPCt ion 01 elangl b tlw IPrfIi (If that illrli(atPll rOl tlulll1Jittp(lliuht It Itlll b( llluliJr I-(Pll that if l(middotndlnJ- IIIP mad n itl I t lIP ~()ll1d()lb lpalll this pllioJ of nmiddotlatirp tuigtility tllP llLot tIOllt thi Olll(P (nil bl IPdUCld to tIl lltini III 11 Ill TIll l~adiltg (illH~ bbll Oil tlHl datn rUl lublwls and llsinlt Illl ginll ill tnhh
50 r----------------------------------------------- f shyZ
~ 40 ~----~W~A~V~E~LE~N~G~T~H~7~5~0~M~P~~~~ ~ --------------------=-=-= ~ 30 f- WAVE LENGTH 540 M~ _z _____ ___ -=- __ _ ~ ------shyt ~_=---=-=--I GUAYULEIII 20 -Z HEVEA ltt II KOK-SAGHYZ f shy
4 6 8 10 12 14 (6 18 20 22 24 26 28 30 STANDING TIME (MINUTES)
FIlirtn 11 Emmiddot of wav hll~rh Il li~ltr tlall~lIIit1alHl aftI IUIlItHt -Imlli lug 111m for guaynh llmiddotn 011111 middotiolIlJh~z 1111111 llijlitul1 flolll 1lHlh~ll1Jllryl k11II11l ~(lilltlll h~ lwitlitll 111Inu1 111l~1It1 2)1111 o1U11111 (Helillins on (illllun tlunhll IlIIJlllw]ntllW111 lutl(I[lholtllllltlt with ijUjt Wlnl IHI Ilf1 I
11 EFFEGT OF Hbli 1 -()JXT10~
Tilt lnblwl ~()h(llh pxtnl( till IPillgt ubo It 1m nllu1- bellt -~atea thut ~lll 11-111- tUP olnbhmiddot ill middottIIlIlOl ~1It tlWIIJI( my U)t PIl (tlIHatcl WIth tl1l lullh(t I tahle lJ 1hln 1- -1111 tIll (llllstlOll of nny p()~iblt tITptt of XtIIl11 diflp]lws ill ((JlllPllttUliollS of 1l-in lil lolutioll alollJ with till 1lIltbpl TIU data ill wbh +ho on tIl( hn~is of (olorilllPill ladillU thaI tll( IIUOIl1t of lnbbll Plllipirntld 110111 Ilwthyl olnlld kptOlll olntioll IJ 1li-jHlllnt 1l)04 in 1-llltlIllt ethallol)- not amlll hy thl llllNlI(l of llvin aU1ouut of llins inolution bull
-----
26 rECHNICAL BULLEfiN 920 U S DEPl OF AGRICULlUHE
100
90
80(I) C)
z Ci 70 UI a 0 60 a ~ UI ~ 500 ~ 0 I Il 40
30
A 20
0
100
90
(I) 80 C)
z Ci 70 UI a 0
60a ~ UI E 0 50 ~ 0 I Il
4-0
30
B 20
0
--
--shy ---shy---
2 4 6 6 10 12 14 16
---shy= ~ ~ shy
-
2
025 05
10
15
20
25 -30
35 40
SO
-60
=70 80
16 20 2224 26 26 30
OS
- 10
IS
20
2S
30
35 40
-50
-60 -70 -80
bull MGPE 25-ML
VOLUME
bull
MGPER 25-ML VOLUME
Florm 12-EtTld (If till1l or Slllldill~ 011 light transmittallce (01 (A) gUllyulc lnUIl(I plccipitllitd frOIll llltt h~l isobutyl Ielollt solution Ily neidilic(l ethanul bull null (B) gUllyule ll~illii pre(ipitated flom aeltoll~lllcetOlll-Cl])osolY( 3-7 solushy11011 by H(illilip(i l1U (HPlldillg~ nt -lIlillult Ifllpluls 011 Evelyn photoelectric colorimellr with jU-lllp tlllll alit U-1I11 npN(lle spp also table 2)
bull
bull
RAPID PI-IOlOMEllUC DElEnMINAlION OF RUBBER AND RESINS 27
TADIbullbull ] 4-ReZation of amiddotmount of middottbber pleeipitate(Z Oln metltlIL isobutyl ketone 80lutions by OS-pereent H 2SO in 95-pere(lIIt ethanol to umollnt of resin8 udde(l U8 indivute(Z by colorimetrio readinU8
(Rubber ami resins cnlculntcd on bnsis of amounts in 5middotml ullquuts of extract from 02 gm of tissue in a 2fllll olumo( bull
Hubucl r~cocrell whcll rcsins nddcd as IndIcated Htbbor al1dcd (pllcollt) ---shy
__________bull_________ ~_12rpcrc~15011crccllt 7511crccnt IOOpcrcent
PerCtllt ercellt Percellt Percellt Percent o o o o o) 50 250 263 252 25000 500 500 500 500 700 750 750 751 749
1200 1250 1250 1250 1250
EXTRACTION TEMPEHATURE AND TIME
Typical experiments to detllmine the time required to secure maxishymum extmction of rubber und ltsills at 115deg U Ilre sUlIlmarized in figule 13 the solvents used-methyl isobutyl ketone for rubber anrl Ilcetonylacetone-cellosolve 3-7 for resins extraction-are very eflicicnt since under the conditions indicttted maximum values were secured after 30 minutes of ext1llction The most eflicient liquid for the bath (lig 1) used in extrtlcting rubber or resins is ~ high-grade cylinder oil (S A E ~O) The sand bath and such liquids as glycerol have proved unsatisfactory
RUBBER AND RESINS STANDARDS
According to the National BULeau of Standards 1-_ lhclc Is no gellcrnlly recoglllz(d standard lIIutcrlul [ior II rubber standard] The rubber hydroCllrbon ill llifferent samples of conmlcrciul smoked sheet or pale crepe from heclI pluntlltions nries from l~ 10 04 llercent of the totul nutletmiddot the most 11Ioruble conditions Of preparation
McPherson () has described a procedure for the pLeparation of pure heve~ (Hevea brasiliensis (H B K) MueH Arg) rubber from crude rubber or latex In the absence howevcr of ~ generally recogshyn12ed stalldard for rubber hydlQcllrbon [caoutchouc (CnHUs) xJ the standard adopted was that of the relnthely pure product secured from gunyule tissue txtractiotl nccording to the Spence-CaldweU method (5) or the motlified PIOCCdUlU of Hohnes lind Haasis (p 2) The details for constructing the calibration CULes are given on page 10 Standard rubber samples apparenl-]y can be stored for a long timc under the conditions des(libed on page 10 The duplicate colorimetric lendings for glULyule rubber newly extracted by the modified SpenceshyCaldwell method were ()J2 ench as compared with US) each for the sample extracted by the same method but stored 1 years In each case colorimeter rcadinllS were made on mixtures containing 2 mg of rubber in It 25-1111 Yolume
The selection of tt suitable standurd for guayule resins presents some dilliculties Tll(~ acetone extract of gUllyult estimated on (l gravishymetric busis~ for instance proved to be variable depending on the type of tissue sampled or season of sumpling because such fractions as
COllllllunlcntion dul(lt1 Octohtr 22 11H3
28 QECHNICAL BULLEQIN 920 U S DEPT OF AGRICTTIIlURE
16~==========================115 shy
14 bulli= 13 z ~ 12
ffi II Q
10 c w 9a w
8gto () 7w a
6a w
5en III ) 4 a
3
2
A 00 5 10 20 30 60 90
14~------------------------------------------- bull13
i= 12 z w II ()
a 10 w Q
9 c w 8 a w 7gt o () 6 w a 5 If)
z 4 If)
w 3 a
2
o+B~~__~__~____________~__________~ 5 10 20 30 60 90
HEATING TIME (111 NUTES)
lllGUltE 13-lDffect of time o( lICntillg O2-gm samples of gunynle tissue with solYlIt nt llfio C on lo(OVl)ry of lllhlJer alld 1Isim Lt HlIhblL extracted with methyl isohntyllwtone B resins Cxtll1cted with aCftonyla(etonc-cellosolve 3-7 bull
chlorophyll are weighed along with the resins in the acetone extruct but are not estimated by the present photometric method (fig 0) 1he use of a diffeJent stanclttrd waS therefore indicated
bull
bull
bull
RAPID PHOTOMETRIC DETERMINATION OF HUBBIm AND HESINS 29
The resins standard selected is based on n relatively pure source of resins the rcsinous exudnte 011 the stems of guuyule plants IJldimishynary expeliments with the resi nouS cxuclate from diffcrellt gllayu Ie strains of various ages indicatc nHlt there is little YaLiation in this subshystance on the basis of Colorimct(r readings 011 2-mg aliqllots of 01shypercent solution in It 2i-ml volume (tabl( li) Expelilll(lnts have shown that the air-dried (xuclate contains 3RtOH p(Ic(nt of -volatile matter This material is l(latiyt~ly stablp ill (OlllpoBition and is npshypurpntly on ly slight ly hygroBcopic as shoWIl ill Ia bl(1 1 Tlrp Ipsinolls exudate may be jJleplpd in two wayi-i fl liSP as a stallClHld-(l) the clpan exudate is clripd iol Ghouls at ()1deg C at W indlPs of a(lIum Hnd aftclbCinOglOund ill a molfalis 1)I(spI((I intn airtight COllilinel OL
(2) tllP Cx7lclate is clissolllt1 ill a(lhllll and filtplpd PlactieaJlyall of the acetm1l is thpn lYapolntwl olt OPI a stlam or atCt hath and Ow residue is dripd ground an(( PI(sPIld as ill tllp fin lllethocl Tlwse two prepalHtlolls a1( (ompalpd in ta hlp ) 111( (((tails fOl ~t()lil1g the resins standald and (onstlllcting the calibration CUITPS alc given Oil page ]2
lAIIIg fi-CUIIIllrsoi (lJ lIr-dr(1I IIIIi 1((11 II II-()I-tr((l l(sil~ 11111111(8 of I II 1111Ie
[Colorimetric rrndill~s 011 1~I11 phulll(Iclrie eolorillJct[lr with i~()middotmll (100- to iiOIIIIl) fillcr [lnd 5-1111 lIperture preeipitantl part ofO5middotPIrctllt 10 to 5 paris of IIOj
nupliclllc(oloritwt([
nIl(lin~s (hIlSlcAg~ ofSlmillXo JrNliltlCllt of fPsiJI$ L1Xtlrlntp on 2 IIIg ofplanls fllsins (XIHIIlt~Jwr 25-1111 vol
tII1(1) 1
leflTs Various _ bull ____ bullbullbullbull 3-9 Colll)Josiltrlairmiddotltlricfl bullbullbull nf)2 002
])0____ bullbullbull _bull __ _ bullbull ~-l Composilld (ri d at n5 C in aUmiddotimh lWUUllJ for l (jOuj(ja hours])0______ bullbullbull __ bull ___ bull 3-0 COJIlpositld disso]NI in neptolll f1l1erNl fl(lf()ll( GGO i(jO (Ivaporntld olT OV(1r Stpl1l11 halh TesidlH drl(ld I1t fi5deg ( ill anmiddotinch VIl(Unlll for 0 houlS bull
middot106 __ bullbull _ Jir~c1rild_~_~_ _~_ ~_~ _ ~ ____ _ __ _ OUu GOifina_~ ~ _ ~~_~ ___ _ _fln~ ~~ ~ ___ ~ __ 6(imiddotI tiliA H)[_ ltlu bullbull i18 tisSflOabullbullbullbull__ bullbullbullbullbullbullbullbull lt10bullbullbull _ tillO llitO406__ bullbull __ bullbull __ bull __ __ lt10_ Utl2 fon591_ fo__ bull liGa oOa 406bullbull _ __ lt10bullbullbull_ li5S OM
j Ph( vnluls in Uw Inst COIUIIlIl indieatp thnt gunyulp fesinous (IIHlnt( wlwtlwr dfircl hi Yn(tlLJ1l1 wilh L~ perc(nt loss of volntllt wutl pr or tWl c1rild giVPd npproxil1lnh1ly t Iw snllw colorinwtCr rNHiing- 011 till busis of aliquot~ cOlllniuiug 2 IJI~ of flsillS lXIHlntp l)tIf 25-mI volultl( Ihil- illdicate~ thl11 Uw UITW IJ1flS~ of olnshytile mntl(f prt~(iJlitnt(d gins npproxilllntlly Uw $1II1l (oiOfirnl1tlf ftudiTlJs ns tho ftsidtw A pnlill1jllaf~middot (XIlltrinllnt indicutls thlli th VUllltill muller l(lIlSists of thl Ilrplne oil fmcl ion I5-(1Il gtnplls or rlsitlOtlS (lxudntll gnvll by stPll1U distillation nn Uefllgl of 011111 of jl(lfPlIW oil with npproximHte tilllsity (If OHIi lind lhus rrprlsll1ll( IlPIJroximllt(I~ 01 Jerccllt Of t he original weight 1hls lllrClnlage complrcs wllh 38 llltrC(ntlost by drvinI( in IICllnllJ
aSplusmnUH perceilt or orlginlll weightlosl
The wailnble illfolJllntioll on tlH (ow-JitlPllts of the gunYllle r(~shyillOllS exudate alld tl1( HeetOlIP ext act of gaylp ti~slw is sllIllmarized in this paragraph lYalttI (u) alld also Hangcn-Slllit lind his coworkshyers 16 reported that 20 percent of the resinolls exudate from gUltyulc stems is parthenyl cinnamaie (CHuOH=CHC020 11JI2r) Steam disshy
15 (OIlIJIIIIUicatioll flom A T Haai(II~l11it llId (0011(11 Calif0111 ill Tnfiitnte of Tccllllology Past(IlIJI Jhps( wOlken al Htud~ing the COTlHlitlllllts of the acetone extract and other conlltituellis of guuyule
30 TECHNICAL BULLETIN 920 U S DEPT OF AGRICULTURE
tillation of similar resinous exudate in the writers laborntory has yielded approximately 4 percent of the whole as the telmiddotpene oir fracshytion Haagen-Smit and his eoorktrs nportec1 thttt about 25 percent of the acetone extract from guayule branches is parthenyl cinnamate and 6 percent of the bark (ltortpamp-phlotm) extraet is parthenyl cinshynamate These workers fm-thcI reported that 25 lwletnt of the nc(shytone extract frolll bLllllches is a compound with the tlI1pilicaL formula CBoH400a 1 percent is a compound llwltillg at 2P to 2T5deg C and 1 percent of the extract from the ]eav(s is tl (olllpoulld nwlting at 100
to 1710 1Valtei (6) reported that 3 to -l perc(nt of the tI(eton( txtract
of leaves and flowering StPIllS of guayulc eonsists of waxlike substances soluble in olgallic soln~nts but insoluble in at(l and (on(ent1llted H 2S04 The flactions mentioned on the basis of (onHLTutle esti shymates of amoullts actually isolated tlecoullted for about H ptIcent of the totalncetollt~ so]ubles extracttd from tll( guuYllle 11 rub The other constituents ltlilaill to be i(](ntifi(d
RUBBER AND RESINS CALIBHATION CVHES
Typical culibndioll Clllves iol Iuhbpl and I(sins bas(d 011 (ldtLminttshytions made nccoLdillg to the plocCdmC outlin(d 011 pages middotb to 1G arc shown in figulPS 5 and 1+ The spCdlopliotoll1lttL en (OIOIjlllctCI readings are plottCd on s(lIlilogalitllllliC pappi ag-ail1st (Il 11IbblI (011shy
100 ~ 90
80 ~ 70 ~
z 1amp1 0 II 1amp1 IL
1amp1 0 Z
60
50
40 ~ltI 30 ~ en z ~ ltI II ~ 20 C) ~ oJ
10 o 2 3 4 5 6 7 8 9 10
RU8BER IN 25-ML VOLUME (MG)
bull
bull
bull FI(lURE 14--Ctlihration curve fotmiddot gllftYlIlc lubb01 (Hct(lings Oil COIPIIHlII tlOl1hl(
monochromator SlCClrophotolllet(r with 7fiO-11IL Illtel alld Hllp Wll ( IHlll()
bull
bull
bull
RAPID PHOTOMETRIC DETE~MINATION OF RUBBER AND RESINS 3]
centrations From a casual inspection of these CUlTes it would appeltr that Beers law does not hold Actual tests indicitted that Beers law was applicable only within a narrow range in the upper portion of the curves The analyticlil results on the basis of photornetric readings nre therefore calculated by direct reference to calibration curves or from reference tables of equivalent values bllscd on the cnlibllltion curves
Calibration curves for kok-saghyz alld heyea lI11tulltl rubbers and Buna S (GR-S Chem Gum IV Goodyear) and butyl (GR-I Standshyard Oil Co Protoc) sYJlthetic rubbers are hOWllil1 figure 15 The samples of kok-saghyz rubber were furnished by the Diyision of Rubshy
100
90 ~I) ()
z 0
1amp1 a
~ a
80
70
60
s 1amp1 ~ ~ 0 ~ KOj-SAGHYZ 0 l Il
50
HEVEA~ ~
40
100
90
~ 0 80z Q 70a Co)
a 60 ~ 0 0 x 50Il
40 ~----~~----~------~------~------~--~ o 2 3 4 5
RUBBER IN 25-ML VOLUME(MG)
FmUIlE 15-CaJiblation curves fOl kok-snghyz h(YCII Bunn S lind butyl rubb~ls (Readings on gy((yn photoelectric colorimeter with i20-lIIp filtpl and 6-ml aperture)
32 TECHNICAl BUIJLETIN [)20) 1 S DEP1 OF AGrnCUIlfURE
Iwt Plant JIl(I~t ignlioll of thi BlII(un and (1( l))(parcd according to 11( SPltI1((-Culd (]] (6) PIO(((lllll Hlpt pal( CLPPe was (xtmch(L with acetone blI()Ieit W 1I(gt(11l a ttnlldal(l
SEXSlllVllY Ol~ llETJIonS
By lip pIO((l(II11P olltlillP(l 011 ]Hlg( +n Iowa (lOOl IIIg (11 1111i(l0shygmm (gHlllllla) of 1hblI ill a 2)1111 yoltll1ll (all )(gt dltpltld Oil tltl Col(man (lohlP mOIlWhlOl1lHlOl l-I)((t 101 l1lOt 0111 ci( I ill1ilnlly 001 mg of Iublwr ill a 2J-1ll1 n]ulllP Illay bl Ilad Oil till EnI)1I photoshyllectlie (O]oLillllt(I Thll ya lllll- 011 tilt IHl-i- (J I (xl ad iOI1 fmlll 02 gill of til-lI tH(JI(lillg to tllP -lllndal(l jll()(pdull 1(PIPStlIt IlO()2J tlnd 002) P(IT(lIt of llIbl1ll IPI)(((inly bull1t1lollgh -lI1t low allils can be d((d(middot(1 il lIoullt1 Ill IPtllizpd thnt till PIIOl ill PlI(Plltng( or tll( al110unt dltlIllIilll(J i ltlatlpl high ill tili PIY lo Itlllgl 111 aetllllllladie(middot Ill( lopl lillliL 111)(1(1 lIw (ollllil ions of tlil ]lI()(lltlIIIl u ol1tlinpd ipt at l11 11I1 or 1111gt11(1 illt i-1ll1 Ollllll IlPIPltPlltillg 01 p(gtl(pnt of JllUiJtL un tlll 1Hli or (xlla ion rlOI11 II rlll of tisSIll
EIlIlOH COSIIlIHIIO
In Oldpl to H(IIp ill )1lHtPltt pl((iioll illlpIi1I- it i lH((SSHI to slnlldHIdiz(i rigidly 111( Pl()((dlll( 0 illdi(ntpd Oil pnglt- - to J( If lids i dOlH tlip lXIHlinwnlal PIIll is t(middotdllld 10 n ndninlllill
Illlt pl(iioll of (hI ]lIPPllt 1IHllwd Oil til basi of ]llllP llIllJt1 alld Ipsinssollltions call hI jlldgl(J 110111 figllll Hi lileh lio- til HPIlIgl d(intioll oft -illgIP lI1lnSIlIlIIIlnt in lHi((lltagl of Ill( alllOllllt 01 Illhshy1)() 01 lpsins d((PI1I1 iJlld TIl( (1101 PlI(Plltaglt H1( gi (1 101 OJ) to
RUBBER IN 25-ML VOLUMEMG) 004 01 02 03 04
i= I I IZCtOW
fbA ICtU CtCt WW a
01 02 03 04 05 06 07 08 09 100 = RUBBER (PERCENT)
RUBBER IN 25-ML VOLUME (MG) 10 20 30
~ I CtZ
bBOw Ctu CtCt Ww o I~
010 50 100 150 200 250 RUBBER (PERCENT)
RESINS IN 25-ML VOLUME(MG) 10__ __3-0_ 40 50 60 70 60 90 100--_-- 2_-0
Ct~ -r- 1 I OZ
WCt UCt b C wCtW
a o I I 150 250
RESINS (PERCENT) o 10 50 100 200
bllI 1tI W-Yllnl dtd1 ioll I I 11l1 11IlI11 1(111(11 1 III Plll- IlIIIlol1 01 IIim~
bull
bull
bull solution Il basis J o golH of tiSSII (JlILCl-nt (11(11) for (~I) (l)1 til O 1I1
of luhllpl lin 1 III I (I Ill of lUhlJPl nllll laquo I J to 111 nlg of IlSlllgt (Itllillgs on ]iYllyu pllolwh-llrk CO[IJlilll(-(PI with nOHIP Iiltlr lIntl U-lIll allcrture)
RAPID PHOTOlJElRIC DELEHlllNAllON Cn HUBBER AND H1~SINS 33
10 mg of rubber anel1 to 10 mg of resins in a gJ-m1 yolumC For
bull
bull
bull
comparative ptuposes the leslllts arc also calculated on the basis oJvershycentage rubber OL tltsills in 02 gllI of tissul As WOlllL be expcet(d the error increases sOIlHgthlf for 1(lali nmiddotly low COlHell t1llf iOlls oj rllbbeL or resins The curves in figure 1(j s1l0 that ill til(gt Illlge Ol to 10 pCrshyeent of lubber the elTOI rangts Jroll1 abollt Ll to II) ]IlC(lIt abo(~ this mlllc tIlt (ITOl d(((ts(s to (ollsidlItbly ltmiddotss (han 1 1lICPllt of tlH mllollnt ltl((Lmill(d Hil1lilally in tlH (lISl of l(sins analysis (fig 10) the ltLTor is (onsit1eIubly INS than 1 PlLllnt ill (he lallgp of 11 t~) ~() penPII t
In nil ([lSl of lllhblI alld (sins lx(Inltpd tIOIl1 (issups Ol addcltl to tisslle lxtlads (s(( tabhmiddots (i H) illyolillg ll01P o(lllntiolls the eLI01
is hig]wl thun that indilHtld in figllll ((j Im pUIl Ill )])p I tllllllsins solutlOII
COlllUCIIOXFOH IXSOLl-IlLl~ Ilgsqgt(Jg
111 th( Jllo(pdulP ollllillPd 011 paw I till illsolllhll isSII Ipidll( tflpl (xttlw(ioll is (Ptill tlw lIask l(lll till xtlct i l1wdp up to yoltlllH It is not rOllPllipnt (0 IPt()PI qWlIltitati(Ir III(lw[olH a 11(1 pllooll extlnlfs of guuyull I is-lll alll thl1l main t11l111 up (0 YOIUllllmiddot bpCaUHI sllch all additiollal stltp wottld]) tillll-C(JllS11ll1illg Th( Iogiea nll(gtIshynntin is to mnkp tltl lXtlUCt Llld Ipsidup lip to OllillH in till original flask andi llPSStllY 10 llwlno tl OIIpdioll wlHIl (allIlnting [hc llshy
Hults f(JI [hl oll111lC displupd hy till ins()lllbh llsidll( III it l)picat (IXpednHllt (ollsisting of Jhp lppJiea(iolls if was Iollnd llftt at ~iiO ( 02 gill 01 Iuhhll pillS IPill-fl(( lisslI(gt (lollpdll fot llwistUlC ou basis of dlyillp ut lOW 101 ) llOlll-j (lbp(ld only t~ llllUll voiul11P of OOk7D~- OO(lOO(i Ill of lllthyl bolnl(yl 1lIOll( (lplhlli(al-t(Tnltle sp gl () Ii I ll(Hli (j at ~)) -gtitllP tl1(gt 1It101111( () r t is-lIl xt Iadld j sl1lall til( PlIOI dul to Ill(gt insoll1blp Ip~idll is slllall III [0111 ill( wOtk it (all lJp diIpgal(ll(l
]hcon~lIY OF HllIllgl AiO HESIS AIH)gl) TO EXTlIACI OP
GlYlLE TISSlg
Tnl)ll G L(IHpslntillp (ypi(nl llld(~ SllOS (hat all a plngl of HIOK PlI((nt ot lltl pltl( Ilhl)(l acldpd to tllP Itll h iolJut1 InmiddottcJllP xhnet
of guayulp tiSI1( WllS 1l((PllIl Tlli nllintioll flOlll (olllplpU I((OYshy
PIY i within flll pxp(IiIlHuttllIIOI ~illli]llly fnbll Ii llows thn 1111 llYlIUgl of 1O(1~ ])(I(Pllt of gllllYllII 1(-i1l- add(d to II( (pllosol( (xshytrae of IUllY]l t i~HI Is 1l(oPIPI
THl~ (~ Hf (Off Ill of 1111)( J OJ I~il~ lItfI(( In ~(JI1IJk~ Ilf (111 [lI1Il fI2 lIII
0 tlUfllllit i~~I1
Instrument
---- ----~---- bull shy 1(1
Colemun ruono~ltrOUlllt()r 2t) II sJl~ctroJlhOL()lIIeter with 2tJ I iflllllI wnclength Fetting 21 II nntl 0-1111 WU HI hUJl(L _ L U
Ill 7Evolyn photo~lcclrie (olor JU [ imctcr with iO-llIl filler IV (I
H1 0 t I I
llImiddot lUn WII 1011 HIO Wn mil lUulon
10 JIg1111 IUI ml lUl anh Io aLn 111)_I ) III li lU It 2) deg wn2SU DD
Irl JIll II IIr II US II
1110(1 lULa lUI IlK) IJ WU
I( llI Htl tNI 1(111 2tlNI HI 0 221) lllil t2S 0 1~ 10 1~13
In (I 2117 I
10U 1l(J ~ 4 _H_j ___
9middotJIlJ5 10115 10 00 lUU5 flUU 4li (tl03 9(11)
leIlKl 1l~)5 lOOU l1KIr JOIS un 003 OIl Ii
34 lECHNlCAL BULLErIN 920 U S DEPT OF AGRICULlURE
COMPARISON OF PHOTOMETRIC A1D MODJIoIED SPENCE-CALDWfLL METHODS OF RUBBER ANALYSIS
Guayule samples were analyzed by the photQ111etIic method and by bull the modified Spenc(gt-Cnldwell mcthod The values in table 7 represhyselltativ(I of typical results indieate It -atisfactory dcglpe of conformshyjty between the two methods in thl range of tiSSlHH with llHHC than OJ) percent of rubbtImiddot On the bnsis of the amounts determimd the results in this runge for the plmiddotts(nt lIlcthod ayernge apploxinHltely j percent highcr
~LAIII~ 7-(oIllJl(i~on of lltlllrIic (IIri mOtllinl SJl(II(r-(ulri-wall IIIrtlwrl~ of rlrrlIIillillfl 11)1)(1 COIIrll of UI(III
1 Flowers frllm amiddotmonth-oltl nursery plants
YAIIIATJO- OF SIli(LE DETEnt1NATIONS Fnoll TnEIIllIEAN
Rllbbel (Uall8i8-Thc plcCision of thc pLcsent method when gunyule tissues Hr( nnnlyz((1 for rubber may be j udg(d flom I Ill datil presentcd in table H TIl(se dahl -how that thl pplCPlltag( uriation of single determinatiom from nwan yullles with low standllrd enolS ranges from less than 1 to 4 p(gtrlent
R(8in~ wWlsi-r-s lndi(a((1 011 page ~j he INntlts s((uled hy the present phoolllttric nsins llHt hod are not tliltly (olllpalable with those of the grtLVimetri( ncetol1l-cxtlt1(tioll II1etho(l Thjs made it necesSllry to selc(t another lalibllltion staudud-tlll Ipsinous exullate from gullyule shrub-thut gies relatively COllstlllt photometric readshyings (table 5) The resin (olltents of guayule roots branchcs or leavcs usually ran(~e from about) to 1-1middot pelcellt The ple(ision of the present methotf WhCll gUHyule thslllS lIe analyzed for reins may be judged from the datalHmiddotpscllted ill table 9 1h(se data show that the p(lcelltage variatiun of sillgle lhmiddott(Lminntions iLO11 meun ynlnes with low standard NTOrs rangcs from about 05 to 4 percent
bull
bull
bull
bull
bull
RAPID PHOTOMETHIC DElEruIINAlION OJ RUBBEH AND HESINS 35
IAIILE 8-luriation inclieute rubller (mallSM of [1wIIle tissue bll thc 1111O0Illclc metwII
Vnrlntlon~Ilbher I (rom mean
ierCtnl Percelll ~OU -22 ~ 25 +27 ~ 20 +18 ~UO -22---------1_______ 51110 0G6 bullbullbullbullbullbull _bullbull
10 ro ----=ii41075 -01 1000 +11 1010 +13
rlln HI itil 1l9~ 1_ ___ =-~~~
115511 ~ US -111 III II 1575 -13 115 b tiS -I a 111 h WlU +22IIM-(middot bull 11K -1Ja Illi c 1000 +03 1J5H1 W +l)7 ll1imiddot tl 1575 -13
Mcnn 15951 131
1102-11 21fJ() +21l102-h _ ~~)SO -17 1102-c bullbull 21CO +21n02middotd ~OIiO -26
2 r~plusmn Il~ 21151 261 I -~-------bull---__ _~~_~______l-___--_
1 lhe$ 1111($ I1n (or SlIlIIllltS Stpnnltplr PHrilClld IIrtlrdlng 10 1hr prollIlIlr( OIiIIiIl(o(I on Imgt$ 4 to IC ~tcond nUlI1 hlr r(J)[ltnts stl1ndnnl llrrot of tilt 1I1(1111
1_1l1~ n-J(lri(iot in relli(Upound rpoundsins (lllalIsfs of VIOJII( lixsue b1 the lhomillric lII(lloli
-- ---~--- - __-------- shybull I I I I Varlgttton
_________~___ ~~lu_n_Jl_Q_~~~_____ ______I__~_o~S_J frOID lDean
Percent Percentgt458-1 ~65 +41IWtl-li 130 -a2Hli8c aliO +26S41i8-d bull 130 -32
1(-011 34I10Olifgt __ bullbull __ ~--====
li-9~2n 881) -06 li-9~2-b Si5 o ~HH2middot(middot S i5 -6$-H2middotd 000 +1
8851 054
O i5 +6 9 i5 +6 950 -20 U75 +6
H-liG3o-n bull -1 n-li6~b bull __ _ -IH-IWH +4H-l61511 bull -1
1tmiddottlU
62~-lI __ 62~-b ij24-( bull OH-Ji
(-Ull
I rll(St oluls nre tor separately ~xlrflCled SllllllllCS IlctOrdlug lO procedure outllned ou pages 4 to 10 i Secoud number r~prtgeulS stulldMd error of lIe menn
36 TECHNICAL BULLETIN 920 t ~ DEPT OF A(]RICCLTCRE
ReUUER A~ALYSrS I~ CRCOE-RcuUER PROOCCTS
Sew rapid photometric m(lthod~fol the ddellllinttion of rubber and reii Hi ill uaYllp ti--ut htp lllell pIPHnl pd oil pag( ~l to In A brief H1111111tlY of It similar rnpid llHthod fm 1I1hb~rllnltlysis of u1lulcanizNl tlIldp lubbll pl(Hlmtlt whielt i~ bn-(tldo on the prill o
ciples dehtilcd tlllLe follows Duplltate nt-gm sllmph of the finely cliyiliNl IlInttlitiup wlirllll out [~ei-()l (all hl lIf((tinmiddotjv INd to lt1iyidl till alllpl) TIll kltolll-olubll portion of till )111(11( tlrc di-olved a- indh-Htpd fot thmiddot lllnkill~ of -tlllHlunlluhhll olutiou Oil Pt 1II hut tIl IUlIp Hn lIn l-fplImiddotd 10 lHI-ml rolllllltti( fln-k antil1ltld(lup to Olllll1l The bnlulUp or till JllO(ldllll i- thatutlilllll on paWs -1- 1 IHI Ii 111( 1(111 1- nIP IXPIP--pd nil til IHi or Iw oligiJla w(lullt of I Ill (I11l1p-I1l11Ilt1 1)(0(11(1
Hupitl PlllimiPJojgtiWllllllllh llIltllOd~ fOJ Ihl llPtlmiddotminntion of ImiddotUlJbll tlnd 1(-illo- ill -111111 Illllph of gutlYllll tiUl IIll dl-eli)ed 111() IlltlY d~o Ill nltlI1lld fOl III Iwl Illhlwl- and l~iJlmiddotb(lLiJlg plant TIllt l[Olllhup hns nlo b(l1l ntuptpl fot IIH lltlIll1illtltioll of lllhbpl ill 11lHhrublwl Pl(Jdlld~ HIIl 1111 hI ndaptld JoJ IIll ann lysis of ynt1J(gt( ic lllbbl[- The llllthmb HIP 1gtn(11 fill tIll fol1owill plimiph- III Grinding
tIll PIOPlly driPl t i~lIl 01 Ul tillg tIll pnHhHt to tll l((lllilllllh~lel of filWlH-- til plllllit qIHlIllilnth( lXIIHtioll 01 IIlbhlI 01 1(--IJl- () llsing oXWllutld olnuh (kttoJls IIt(talp and() fllltil for LIbbel and IH(ltIlIlyptIJllIllIoolYlnJld-o flJllh 101 niJlsl with t(lathelr high IlPililig points 111 to n C) l]olle or in mixt tIll thllt Pll mit tlll rnphllxututioll of luhll(l OJ [middot(ill ill ~() to (l mi1lutp It r(latiwly high 1lllIllllltlltP Ill to 1~11 ) l) lllllipitntillu till luhblI OL Imiddot(ill frolll aliquot () f till oltn ion I IlIlllI-i () f Hlltabhmiddot pl(~(i]litallt (willifhmiddotd lthmwl fOl IIlhlHI Hild llitlifild lllr fOJ JP-illl t~) IIlHkillphotollllliilPIIIIiIlof PlllPlltal of liht tLaIlS mittUl(P lIftlI IlIlbll (II Il in PIlipitalioll 11 II WI( Iplllh thnt (limiJlall till PIIOl dill 10 xtralllOlh (0101 (till dptl1minntinll Iph jill 011 tIll dtwlopllIlJIl of H HIli rOI1ll tlllbidity 111 hpl than I (olot rI
jJlIlpOP-ofallnlyi-I ( p(lllil1thb IIllijOI1ll turbidity or 1llt[lIinmiddotd d(ltl of jgtIp(ii(JlI l)~ lIltlkillU tIl plllltollllmiddottri( ntdillU al tandinu tiJlH~ (dlllilll wlli(h IhlllH(lill-- IP 1llutinmiddotly tnhll) t1ll1t an hlsl~1 oil the (oJlItlIlllItion of IIlhlHI Ill I(ill (lIPIipitat((L
TIll -I(p ill till jll()(Plhul HIP 1-- follOylt (1) 1l~UIIL uJ1lplls of thwl UJfJlllHl (II tliddl(l HUt dlipd 11Illtplial an lXIllltel with11 Ill of till nlnll ill t (oU tlllltIPlll[gtPImiddotatlup oil Iath at 11 Cbull fol 11 minutl I) iIP1lIin(middot(lohd til( (XUtllhllll Jltldl lip to It middotml ynlmlll til( (nlifild by (Illlifllgiuu HlId thlPl IlI nliql1ot of tIl (IalioPlllxUlltl nll Uillltlmiddotll(t to l-llll OIlIIlIllril fiuk- (1) For a trial Ilnditlg 0111 III tlll j liJmiddot~t IllHII IIjI to Ohlllll with lilt Pll shy(ilitnnl a 1(11 it 111 (Dod fill llli lIut ( ptotoJIIltlil IPtlllillg-- of pllllntnl or liuht tlUtllIlillal(I oil n (lpel OphotnJlllllI at rase hng-tlt (If 11 llJ Ill Ol It lollllil1lPtImiddott lloyidld with tIll P10]11 I 1110110shy
Ihlolllltt hmiddot Ii1llI Olllhi lIatioll for -1IpItillg UJlproXilll1l tply Wtl P ]Plwth )0 mp are HHlltk TIll Illldillg lliJtaillld fol tIlt 4-milutl tliall(~ll-
bull
bull
bull
RAPID PHOTO~IETRIC DETERIINATIOX OF R(BBER AXD RESINS 37
ing are referred to a table of equhmiddottllut~ previously p1(pa1elt1 on the
bull basis of 4-minute reac1inJ~ for tilE nmge of lot1telltlatiol1- of rubber or resins to bE elHOlll1t(led tmd gidn thtmiddot -tnnlillfr tillIP fill rUbbEt or resins aiter prE(ipitlltiol1 lwfolE photoIllNliI j(tltlill1 un IUade The r(middotnmining dllplllatt aliquot lll then HHllil up te ol1l1Jle and lpoundadillg ale marle ut the -tandillfr tiUlE iudklltll ill rhl tall1lmiddot for the final r(adillg~ -1) 111( milli1lnm or p(tCPlltllt- of lllhbpL (II 1(-in pr(s(nt are rpadholU a prlpan(l table of lquiltlput for tlll photoshymetric readings h1~l(l ill pnell e1-E on pxpPlilmlItal lhln 1111(1 u-ing as stimtlltlds pure luhbll in 1l1bbtl milllYb aIHI guaYllh ll-ill- lxIHlatt~ in resins detNIl1111lttion I
LlTERATlRE CLTED
(1) lUnSbull 1fl36 THE mURMIXTIOS IIF IOTA RE I III OOl THER llT~II
F1 bullrol IlY U(T1l0fll UfSlfi ~rrnrl r flm lt1 KEYS TI Bill Chern 114 44J-l59 illns
t1 ~ICPHHlObullbull T 1J3bull~ lUTHOO roa THE PtRInCAnu Or a(lIUl IRrIlHU It of TIn
PLRIHEU Htllllflt [ i Bill lallllall 111 Rmiddot 711middotj iIlus
I ) RHBERG P B Ul5 A METHIlO Or ~u(ronrll-nl Hi tIII rUIl[1 f71 ii illlI
bull 14 Hoss W flbull and HARDESTY J O
llH IR1ltDII Of HfITilIZfmiddotR DllIJS ltt 1 Yl fll Off gI bern JIIIlI i ~middotmiddotlf IIl
101 SPEltCE D nnd CuoWELr ~I L 1933 DETER~n-ATIOo OF RtBBER Ii nrllllpoundRBfR Iusr 1uI II1 amI
Em~ifl cttIliIa~~ r Ell i 71middot7i l11 (HI WALTER E D
1U44 ISO~nlS OF PRTlltSrr 1trHpoundV bull l UI n W lHHt (Tnmiddot 1ETS FROM GiYI l~iIl lItr Clttrn SII J UI titJ middotn9--C1 ilIu
17 J YOEbullbullr H lO~( roLORIlETRT 771 IPmiddot nl -W Yurk f H Plrwptric hmica
naly-II rimttry lUll XphHHlnmiddot~ y 1 1
11
HI) ~ fPHELolzTRf 57 111bull Lin xw Yk t H lt PhmeHt CblUlmiddot ila AnaiY~l~-(H lithrry and XIhmiddotILpfIY Y wirh enomiddot rrJlllrjr hy H KtlJnJU11 I
t~1I --- and ~ARVER L 1f41 nlua-w ~in L liLhr IS IP ll~ XIW Yrk
bull For-sale by th~ ~a~fr1nt~nf1ent Dt~c~~ogtnts-~ s t1i rArnn~ut Pn~~~ tJffieshy
Washington 5 D C bull Pl lU ~nts
12 TECHNICAL BULLETIN 920 U S DEP1 OIr AGRICULTUHE
RUBBER IN 25-ML VOLUME(MGl
100 1~__middotOT5___ITO___15__2~O=--_bull 2r5_---= bull 3rO__~-_40 bull99
98 shy(I) CI Z
~ 97 ItJ II
~ 96a f-IIJ
e95 o l
94
93
92 ~__~__~__~____L-__~__-L__~L-__~__-L__~
o 1 2 3 4 5 6 7 8 9 10 RUBBER (PERCENT) bull
FIGURE 4-Cnllbrntioll curve for rubber in 02 gill of gt1n~ule tissue containing 01 to 10 p(rcpnt 0 lllbhlI (nlnllillg~ (Ill 1111 J~pl~ll llhooplf(middotttmiddotlc colorimeter with 720middotmu filter und amiddotml uperture the 01 divisions required in actual pracmiddot tice for photometric IclHlings arc olllittltd)
Similarly hl the range 5 to JO mg pel 25-ml Yolume the desired conshycentrations of rnbber urc measured from the O2-pllmiddotcellt solution The complete data lire plotted on semilogtllmiddotithmic pttpel as shown in figure 5 A
STANDARDlZATJON AGAINSL G1IA111 ETlIIU 11 ETHO()
1he alternate ploee(lule of stt121l1ald izing th~ IneHell~ method ngninst the Spellcc-Cald well method (II) altholl~h flaSI hIe 18 not adVIsable because of the extra work J(quiled ancl the introduction of the expershyimental error of the benzene extraction method
HESINS CALlBllATION CUIlVES
The procedure for constructing cal])lation eUlves for resins ttIlulysis is similar to thtni outlinlltl for lubb(l lxcept that resins exndate of gunyule is lIsed as the resins stundard The resinolls exudate disshysolves very readily in the resins solvents listed in table 1 It may be prepared in two ways for use as a stnndard-the clean exudate as bull gathcrcd from the plants is dried for 6110mB nt 65deg C nt a 30-inch ltcuum or the oXllllate is dissolved ill acetone and filtered In drying
bull
bull
bull
RAPID PHOfOMElRIC DJllImlMINAlION OF RUB BEn AND HESINS 13
RUBBER IN 25-MLVOLUME(MG) 2 3 4 5 6 7 8 9 10
r~
eo en ()
90
f--70z Q ~ 60ltl LIJ a ~ a LIJ 40 E 0
0 50
~ 0 ~ I 30 0 ~
A 20 I I
o 25 50 75 100 125 150 175 200 225 250 RU88ER(PERCENT)
RESINS IN 25-MLVOLLIME (MG) 2 3 4 5 6 7 8 9 10
1--90
80
en () 70
I z Q 60ltl LIJ a
50 0
a ~ LIJ 40 E 0 0 ~ I 30 0
B ~I20 o 25 50 75 100 125 150 175 200 225 250
RESINS (PERCENT)
lJIGunE u-Cnlibrutioll cUve for (il) rubhcr in 02 gill of gllnn11c tisme conshytainingl to 2G perc(lt of 11IUU(Il I1na (1]) rpSillS in 02 gill of glI1~l1ll~ tissue (ontnining l to 20 nelecnt oC l(sin8 (U(ndings Oil 1111 E(lI~1I llhotollectlit colorlmeter with 720-mtL filtcr and O-ntJ aperture the lO divisions llquired In uctnul prllctlce for pitotoulPtlie PllllillgS tlre omitted)
in vncuo arelntivply HllHlll qUllntity of (xutlnte is plllcel] in a lalge dish since the mass rOHmS nt the beginning of the drying process Pracshytically ull of the ne(tone is evnpollltpd olf oyer a steam Ol WItter bath and the residue is dli((l pnlYllized in It mortnr and preserved by
14 lECHNLCAL BULLErrN H20 U S DEPl OF AGRICULTURE
drying as indicated for fresh exudate In all ClSeS the products are stored in airtight containers in a dark coul place
The usualllnge of resins from gunyule tissue is about 2 to S percent on a dry-weight basis For work with this plaut therefore on1~ one curve is needed A typiCallesins ealibrntion CUlTe is shown in figure 5B
PnocEDuuE J~OH RUBBER ANALYSIS
Duplicate lXiLllCtiOllS arc made for each tissue analyzed and duplishycate photometric readings are made for each cxtmctioll the final value therefore reportcdreprescnt- nn avcragc based on the four phoshytometric readings
Thoroughly mixed O2-gm samples of the finely ground tissue are weighcd for analysis on the basis of l11oistUlc-frec tissllc The samples arc weighed to an accuracy of 02 mg Oil an analytical balance The method of deriying factors for making eOllections for moisture in samples has been thtailed on page
The weighed samples arc trallsien(c1 to the 2-m1 volumetlic flasks with the aid of l-inch glass funnels and 20 m1 of methyl isobutyl ketone is added to each flask The contents in the Hasks are heated m a constant-temperature oil bath at 115 0 C for 30 minutes uncleI a yentilated hood rhe flasks are removed and any adhering oil on the outside is wiped off with Kleenex 01 H similal cellulose tissue the C011shytents of the flasks am cooled to a standard tempellltule (25 0 in the writers laboratory) in a constant-tempelutllre ater bath provided with a motor stirrer if available and made up to volume with the solvent After the contents are mixed the flasks are allowed to stand for a few minutes until most of the insoluble residue settlcs to the botshytom The extracts are then carefully poured into JO-m1 heavy-duty centrifuge ulJls so as to include as little as possible of the settled insolushyble residue The centrifuge tubes are stoppered with cork stoppers and the liquid is clalifiecl by centrifuging for 10 minutes at 2000 revoshylutions pCI minute The clarified lIquid is poured into 25-m1 volushyl1Ietric flasks plOicled with ground stoppers It i impoJtant to pour off the clalificd (dlart in lWIt a lUlllie that the ill8ol11ble cNi(hwis not Sti1((Z1tp A 1-in(h funllel is plncCd in the neck of the volumetric flask A filter stick (fig 2 D) is inserted in the centrifuge tube through he liquid so that tlH enlnlged palt of the gtiek seals off the insoluble residue and a small portion of the exmet in the cone point 1Vith the index finger the stem of the filtel stick is thell held against the side of the tube towllnl the analyst who holds the tube with the thulllb rmtl t11illt1 fingCl The txtlHct is thell poured off easily into the yohunetlic flask without distnrbing the insoluble residne The COllshytents of the Hasks are then ))ollght to the standard tel11pelatme in the constant-tempentl111e wnter hath
The reagent blank us(d wit h the spectropllOtoll1lter 01 (olorimeter ig prepared as follogtvs ) 1111 of methyl isobutyl ketone 01 other solvent used is pipetted into It 25-m1 yolumetric fiask and 01 ml of protective colloid solution for rubber is added the mixtule is made IIp to olume with acidified Oil-pelcent ethnnol and mixed again the rcquired vo]shylime of the mixture is poured into a cuy(tte or an absorption test tube
From each plir of tissue extractions to 5-1lll aliquots 01 the clarishyfied extlact at the stnndanl tempCraLule ale pipcUed into 2ii-m1 volushy
bull
bull
bull
bull
bull
bull
RAPID P1IOTOMElRIC DETERMINATION Ol~ RUBBEH AND RESINS 15
metric flasks and 01 m1 of protective colloid solution for rubber is added to each One additional5-mL aliquot from each pair of extracshytions is similarly prepared to serve as a key to the standing times for the final readings as indicated in table 2 These additional aliquots are first made up to volume with the precipitant acidified Do-percent ethanol mixed by carefully inverting the flask three or four times] and allowed to stand for 4-minute periods before the reading is made on the colorimeter Vith these preliminary rendings a~ a basis the standing times for final readings are taken from table 2 For example if the colorimeter reading in rubber analysis at 4 minutes is 655 then the standing time is 15 minutes
The two rell1Lining duplicate aliquots for eath extraction are then made up to volume with acidified D5-percent ethanol mixed by careshyfuIly inverting the flask three or four times nnd allowed to stand for the required number of minutes as established by the preliminary 4-minute trial readings (table 2) before the final colorimeter readings are made on the contents of the flasks
TADLE 2-St(llllliIlU time for variolls (OllccntratioIlS Of rubbcr or rcsins aftcl iJleaipitation bcforc colorimetric readings mc macle
[5middotml aliquots of rubber in methyl isobutyl ketone or of rcsill~ in ncetonylncetonemiddotcellosol e 3middoti both made up to a 25middotml volume with pr~cipitantj readings on lvolyn photoGlectric colorimeter with i20middotml (690to iiOmiddotD11) filter and Umiddotml aperture]
RUDDER I
Range of colorimeter Approxima(e S~nuling i Rnnge of colorimeter Approximn(e Standingtrial readings after 4middot range in conmiddot tJIIIG for trini r(adings nfter 4 range in con tifillnlOalcor minute stunding time tcnt In tiSSU(l Unnl I t I t (rending IIlIDU C stum Illg lOW _ tent III Issue reading
Percent Villlits II Perfe~lt Jfinul 955-999 bullbullbull bullbullbullbull 09-01 00 01-03S bullbull ~ _bullbullbullbull_ Jl-O9 10 743-954 bullbullbull ~ bullbullbullbull __ _ 43-10 30 1420-550 bull ~ ~ 137-94 5 6_3_9-_74_2__bullbull_ bullbull bullbullbullbullbullbullbull_-_---- 6__8-_4_4---___ bull ~ ~ bullbull ____ MQrcthan 13ibullbull_-~_ _ ____ 15_~elow t~ 2
RESINS -----------------------------~--------
957-999bullbullbullbull ~ 139-01 60 11419-amp11bullbullbull _bullbullbullbullbull ~~ 13~5-939 10729-956bullbullbullbullbull_ Ii 25-1 middotJO 30 ~gtl2-40(L bullbullbullbullbullbullbullbullbullbullbullbullbull _ 2025-1320 5 595-728~~~ bullbullbullbull 8 as-G 20 20 IBelow 292 bullbullbullbullbullbullbullbull- More thun542-591 _bull ~ bullbullbull_bullbull_bullbullbull 038-039 15 2025 3
I Precipitated with O5middotplrccnt HSO in 05middotpercent ethanol When the npproxilllull concentrntion of rubber or rcsins in solution is not known trinl colorimeter rend
ings atmiddotJ minutes s(nnding till nrc mndelS n guide to the required finnl standing time indicated in the last column III prncticc UII cxtrn nliquot is prcpnred for precipitation and thIs is discarded after the trial reading is mnde
3 lrccipitnicd with OmiddotpcrccntlhSO ill HO
PnOCEDunE I-On UESIliS ANALYSIS
The procedure fol resins unulysis is the same as that indicitted for lubber analysis eomiddot(I]lt that f he -olyent js acetonylacetone-cellosolve ~)-7 tht precipitant js O5-perctnt H~SOI in H 2 0 and 01 1111 of the protective colloid solution for nsins is added to each 25-m1 flask conshytaining the aljquot of the extract before the precipitant is added
PnOlmmlHlC INSlHu~mNTs UECoIUlENDED AND CALCl]IAlION
OF UESurlS
Photometric readings of percentage of light transmittance (T) ale made on the Coltnum double monochromator spectrophotometer at
16 lECHNICAL BULLElIN 920) U S DEPT OF AGHICULlUHE
750-111 wave length or renclings n1( mnde on a colorimeter pLoic1eri with the monochromatic filter eOIl)Il1l1tioJl for sllecting the npploxishymate wfLYe ]cngth at 750 1Il~ For routine deterlllinations the Evelyn photoelectric colorinwt(r ployided with aTW-lllJ filteL is IC(0l1111HIHtll
The liquid in hich the preeipitnted lubber uld rcins are susshypended is pOll(d very cHrdully down the ill~idl of th( clette o absorption tube to lLYoilllllC fOLll1ntioll of ail bllbblls Aft( LUbbet find resins preeipitation wlwn the EnLynpho(otkcllie (olo1imetll is used the readings are nmde nft(L thl standing tillll- hOWll in table~ It has been foulld (OIlllliellt to 11lPtipilatl tublwr 01 llsiIlS from the aliquo(s at ~-millute illtlLvals This allows stlilieipnt tillle to check the eOlolimet(r and to makc 111( lNHlings Vlwll a ehangp is IlltHk fLom onc rending 10 the l1lxt it is advisablp 10 llle the clIvctte 01 absorption tube nt lpast twkp with slllall p(Iltion- of the llllltiol to be leitd
After the colorimd(L lluding lta e becll Iltndp till IlIl II igllIlllS of lubbel or resins or thc lpL(el1hlges pnslnt in Ihe aliqllot are r(u1 from cal ibmti(Hl (urVlS (fig~ 4 and raquo or from plepn Led tables of eqllivallBts baecl ill each (liSP on (x[lerimPlltnl data The results are expressed as percentages of dry weight (S hours drying nt 100deg 0) of the original tissue The errol lltle to lCflyjng the insoluble residtH in tbe voltlllletLie pxtLHclioll flflsk wlwn the pxtrnetis being mnde up to YOlllmC is V(ly slight sinlte only (U gm of tissue is used FOLroutine allalyscs lhis ery slight eLlor mny be dislpgnltec1
EXPERIMENTAL RESULTS
The experilllCnlal reslllts Oil hi(lthp method- of tU)lPI and l(sins analysis a le based ttl( d icussld blicfly hlrehl
PHEPMINrlON OF SAlULES
No difliclllty was expPtitI1(ed in pltparing slmplls of llllrscly-glOrt guayule plants 1pss thnn ~ YPH1S old 101 rllbbpl alld IPSills analysis In the cnl of Odll filld-gl()n gllayull plants PIIOtS hopel mtty be introdmp(l by the custOlllalY Jlwrhod 01 pICpalillg Ihp sampl(s 101
HlutlYHis as is lwipfly i n( ita ttd ill th is s((tion Smh enOlS do llot nffCct the ])lCcisioll O[ t1H llwt hotls for LllbbtL n nd Il~in~ nnn I sis i nee till) are due solely to tIl( tbsup--ampling (llo(pdule in thi (a~e of oldeL field-grown plall TIll 1lllt1lOcl of salllplill7 fipld-gl()l1 plants JllOLC than ~ Y(HrS old thenfort Ieqlliles iurtlHl jnttigntioll
lgtAHnOILr~G FOR HEllOVAL OF UUVLgtS
Parboiling which (onisls in boiling gllltyule plants in water [OJ
8 to 1~ ~ninll(s ~s col1llllonl) uSNl a~ n llHans of Itlli rCnl()y~l prior to drymg nnd gllnllng It I~ tHI([())P ll(e~Sllr to ltItLeLnunc all possiblt~ eflct oi tlti PLOtPlllll( )ll (Il( final results Exp(liments have sh(nm that (helt i- fl Flight loss ill til tmiddotjght of lOO(S and 4(ll1S In I typi(ul lXpelillltll hlu1llHs of ~- ii) -1-ytII-old gllllll( pllllb were Italnd at randolll Olll ( of talns wa- paLllOil((1 and the le~es (1( haIHI-pi(kpd [lom till o( hpJ Ht Both pis (1( dlipd for 48 hOttlS at (i) C in a llI((lwlli(al (011((( ion Oyell Th( lpsult are SUI11111I11izNI itS follows
bull
bull
bull
bull
bull
bull
RAPID PHOTOMETRIC DETERMI~ATIO~ OF IfCBBER A~D HESI~S 17
Dry ucilht lust ill lariOilillf
Plaut (pcrcrllO 1 1 -I2 ___________________ _
213 _____bull _____ bull __ _______ ___ ____________ 12 2(
pound(111_ ______________ 1 R
4_______________ _______________ __ _____
A __ bull __ -_
The efred of parboiling on till final lllalp i SUllllllatmiddoti7(middotd ill figmc G Rubb(1 lecoYelY w(t about 1 percent higher for parigtoillltl plants and lEsills re(ovelY somewhat o-er 1 i)(lr(lllt 10Wlr The (Ii tference in lublH-l r((o-elY cannot be ae(01111tltlt1 fot by loss in dry weight _ due is to be found in a study of thE grinding lwhadol of a parboiled and an unpnrboilEcl shrub The grinding of the patboiled shlub in the hnml111 mill is much fadlitated and ns a rule for tissue with a rubber contCnt below 10 peteent llO aggregates of rubber deelop in the 1Il11ehinr during the (Jpelatioll Yitll the unpnrboilNl shrub some dillictdty may 1)( (lxppliellrl(l Sill(( sOllle of till sti(ky ltxlldutl Oil the plant may scI( u nlldei for the fmllHltioll of lublH1 ngglPgates Til is apparently explnins the npparlllt los in ruhbpl frol1l the llnpariJoiled hrllb as eompnlelt1 with thl palboilld (fig (i) TI1(loss in r(sins
II
RUBBER
10 f-
Ishyz LIJ 0 0 LIJ 0
9 --RUBBER -shy-------shy
-- RES INS -shy---shy-----_
IJ) 8 I--Z IJ)
LIJ 0
0 7 f- RES I NS -0 -shy0 LIJ III III J 6 f shy0
LEAVES REMOVED BY PAFltBOILING
5 f shy -shy - BY HAND PICKING
4 I I I 35 30 25 20
SCREENS (SIZE OF OPENINGS IN MM)
FIGlRE Ii EtIe(t IIf pnlticlp sizE Oil lEcorPQ- of rubber lind (iiil1s when lEgttiye wEre remond hr Pl1liloiling lind h~ hand pi(king ((Dlltrol) plllllt1lt groUlld in t hammer mill
6114038-46-3
18 TECHNICAL BULLETIN 920 U S DEPT OF AGRICULTURE
recowry from pUboil(d shrub may be due to the loss of the resinous exnc1ate during parboiling This exudate forms ns It SClim on top of tlw )iquol in the tank
On the basis of t1wse results the recommendation is made not to yaly the nwthoC of leaf lemoYal in any 011( lNi(lu(h project Then fltirly compalabh IcmLts should he obUiined
70 ~------------------------------------------~ LEAVES REMOVED
BY PAR80lLING ____ BY HAND PICKING
60
-I-Z 1amp1 0 50 a 1amp1 a
en 1amp1 gt1amp1
40en gt-CD Q 1amp1 Z
I shy 1amp1 30 a l shyx C)
1amp1 ~ J 20 I shy 0 I shy
10
O+--L__L-~__L-~~--~~~~~ o 10 20 40 60 80 100
NATIONAL BUREAU OF STANDARDS SIEVES (MESH)
FlGntE T-lJiMlil)utiun of l1Ultkh si~(s of gnll~II( tiSSU( JrIOllll(l in a Ball amp 1ew(1 mill to pass six dllIerNlt S(I(euroII 1(IlYes Iemoved from plants by palmiddot boiling 11(1 hand picking ((olltloll dpfo1iatld plants dried to 1I lUoistufl l0I1t~nt (If 01 to o) 1)(ICl1It ground tiSSlli IbalH1 1() minutes ill II ~i$hel
bull
bull
bull Kahn shuk(f
RAPID PROTOMETRIC DETER~UXATIOX OF RrBBER AXD RESIX-i 19
GHl~DIgtiG
bull Th~ entire pant 01 plant l)iHt a~(gt fl r(ll it pllllIIirU1ry lSillg fur J hours ntGi~ C prIOr tD t 1( plChmll1atmiddot rLlmhll III a II lItmiddot or n Ball amp Jewell mill ~n llltllysis of paldch lzP- nftl~l (oar-( IIindill shows that tlwy ar( about tIlt llllH fOl parbojlP(t awl IJllllluhoileu hrubs I fir 7)
The coalilly gloUllll ample i-- thPll Ildlll forI toUtmiddot at ni C afnr which it ha lllilobtllL(gt output of ~ llllut lII hmiddot- dptPlIIlilwltl by drying submlllpil- at 1110 fot hOtll- TIll 1 IIIIll i lltllt lmiddot0l111d hi a IluninHl mill TIll mo(lel uP(t in thi IIIk i 1I Hu IIIOilll mill as IllUllifill bv Hoss nnt Hartlet ( 1 -[1lt111- with n1ll1l1 pldushyrations ittI lilnbhell b rill HanlIolll V0ll11nHiol1 ElIillllmiddotrill (0 The size lutllihl11 iUlJnole So I ( 111m t ~ II t HUIII Xl) ~ I L~ 111m nnd So 4 lillllU1 11 ttllilhmiddotj 0 r tllP Imiddotlult~ p(lln-It willI t11(e Sll((IIiZtS with )arl)Oiltll awl uil)Jtllboiltd hrlll b lOwl1 in fif1l1fmiddot-- This hows t tnt 1middottttIl ~(I 1 llllll (Up jlllilnl IHlt that
r------~-------r--- ~ --r IHAMMER-MILL SCREEN
O~ NO1
NO2 ---shy U NO 3 ---II
I
bull lL
z
r ------ l 30 ~ gt III
i I Imiddot
i ~ I
I 1 I I
~ 20 I - 1 iii 1[ r 10 ~ ~ ~ I _ ~ I r A bullbull
o bull L-~__~__~~__- ~~ 20 40 60 80 100 40 60 80 100 200
NATIONAL BUREAU OF STANDARDS SIEVES (MESH 1
Yutln I i-tlillltiuli Hf pur id lZt f ~naY1l1 t middotnt r1 lI1 i ~ a hatlltlllI 1IIi11 to 1111 Lx IHtllllH middotIn Lt-anmiddot tIlllunl loy la1 litkh~ omrl t 1) tHul parbuih~ -t B ~ thmiddotfuliufptl ]~lahr thpt tu tt fit t 1 It+gtr-tt1 Jnui~tHn eunttlIt _~rnlitl tl~UP ltakmiddot~~ 10 UddU it~ 1 rtmiddot4~pt~middotK1~r ttakt-middot
bull So 1 gingt- 11 tt-liuin-Iy ltr~pl [lPlItl1tat of iilll 11animiddotImiddot- Eqltrimiddot tIlllll hnnmiddot llOWIl dutr fll llltldllllUU xtlutioH 11pound lnhbll lIl lP-ill frolll IolUlIl ~tlaYlllt tl-IlP by dlt IJwtmiddotlUlmiddot lItlilwd oil Ill 14 - 01
i-mllt 11111- -lwltld hi INd I li~ Ii I TIll lllhtIlttj of Itiu~ So 1 (lltll j thnt 11middotmiddot01middot lttwmiddot to amplil tltt Iollllli tilt art lpdnn ib
IntIIll ll~ i po--ihJI with tI lLllit Ilfltl[lll1t It honld l Plllplw izmiddotl rImt ilt tht h of -allllhmiddot with l lllblPl
~ontlnt of ill PPltllt til lIilll it i tlllt pll--ihl 10 11-middot t(1i Xli L
20 TECHNICAL BULLETIN 920 U S DEPT OF AGRICULlURE
Even with screcn No 2 difficult due to rnbbel tlcrltreCtlltiollS may be ob tl
encountered In thes~ caHeH it iH lWit to parboil the shlub fOL leaf lemonll and finally to dry to about 1 to ~ P(l((llt of tnoiibl1(l pound01 b(~t results jn ~rindillp in tlH hanmHl mill
It iH aclvlsable to provic1l thc hammer mill with a ground wire Hillel the presence of static electric (harges 011 tll(middot partkhH will ealls( Home of these to atlhelc to the inside of tllP (olltailWr OJ lila eallsc OI1l( of till pULticl( to form ngg1(llatls EIIolin lalllpling fl01l1 fhis SOI1I(I mlly be (onsi(h1llbl(middot
A1I10l1g the Holnllts with high boiling point that lIlay Ill IlHld in rubber anal)Hs I1IP Illllhyl n-alllyl ketolle methyl ioblltvl kptOIH diisobutyl (tOIH blltyl tHptate llethyl amyl 1Ittail (middotthyl(middotlllmiddot gly(ol diethvl (middotther and n-bntyl (middotthel (labl( 1) TIHse al( also I(sin 01shy
middotent but th( 1(~illS n1( held ill olution by the rll1)bpl pl(l(ipitant tthanol wll(1 lllbb(r is 1)J(lipitatNI (S(ll tabl(s alldmiddotl) On tIle basishyof the lxpHilllPlltH tll( btsf nil-round lolPlli -rol lS in 111( PIlHPllt method is lt1iisobutyl kPtonc wld(h was not IIltlllllfaltllllmiddotd ltIlling Vodd Yflr n A suitable Sl1lgtstit ute iH llHthyl jolllltyL htolt whi(h is l(porhd as llolltoxit UJ)
Clllos()IY(~ (ethykn( glYlol monopthyl (tIH1) blltyl earlgtitol (di(thyl(ll( gly(ol llIollobutyl (ti1(r)~ and acttonylacetOll( may be used as resins sohrCllts (table ] )
In the earlipr work with (sills analysis cpllosoly( alolle was selcmiddotet(d as a suitable solycnt Aitholllh (ell()~oh( alone is pxc(lllnt its rplllshytiwly gwatlL iscosity 1(I(b to bubbl( formation nft(I (SillS pr((ipi tatioll Thi- increased thp (xperimentnl (LTOI OIl of tltp othll I(sins solpnts tI((tollyla((tolH has the proppry of glpatly lNlulingshydH(OSity 11(11 altld(( 10 othr liquids This sohpnt tlHIeforl wa addp( to ((Uosoh( in slIflici(lJlt tlllIonnl to OPI(0111e the dinieulty On the basis (li~ex)le1inwllts ~ purts oi~ a(donyla((tOlll to I puts of (elloshysoh-f (bolll by olume) as Splldcmiddot(l Thp 01 hel Hoh(nl listed hutyl clLlbitol at l(llst the t((hnieal-g1lld( ploduct uSNl is appal(ntly not as good as eithe of t1w ot1(r two () a (ombinatioll of tlWSt
The SOlVllIts JOI liSt in tumlyzing artifkial lubbel$ hy tlw pr(senf method appllLently (lcllIHl on th(middot kind of llI))(I lIp-ityl (Jxidt is suitable Ol BUlla fi and hutyllthlI for butyllllbbl Tlwse reagents IlLe technical g1lld( Calboll amp CtllUil1t Ch(lllilai (OIP This Hllbjp(( hilS not bepn (XtpllHl(ly illwtigated by till WIit(I
PIIECIIIIJ-
All tlst fOl Ih( adlqlJalY or till IHllipitullb ll(Ollllllentillllll11Sl bl baset] on the plctisioll of tllP final I(snlts oiJtairwd with the methods The )redpittlllts s(1e((( n HpJ (xtcllsi( (xp(IimPlltatioll all HatiH~ factor (Hee fig Hi 111lt1 tabItmiddot (jH) Ext(IIin tllts llllTild Ollt hanmiddot shown that H Hatil-gtflltlOIy [gtIpeipitallt 101 1lIbblI is (li-p(IT(middotnt HzHO (c p reagent nil POll sp gl U-lmiddotJ) ill li-P(l(Put (tinmol by vohmlP liol (tllayul( Ipl-gtinl 1l)-P~ITImiddotllt H)~o ill Hl) by ollln( ii lL satishyfaeto7-y l)lp(ipitunt A solution of 1 palt of H~~o to 1 part of H~() (1-1) iI2So1 nnd abo yarious int(lIlIPdiat( proportions of tlllse suhshystanCPs giyp fait 1(511It8 but with till inlIptl(l ill [h(gt ratio of H~S01
~
bull
bull
bull
bull
bull
RAPID PHOTQlIEfRIC DETEMIlXATIOX OF HtBJER AXD RESIXS 21
to H 20 the )olutioll becollles somewhat vbcou5 and precautioll Il1Ult be taken to ttvoid bubble formation When it i5 poured into tilt Cllvettes
It should be lloted that both of these precipitants have an ftellleshymmiddottion It was found that when XHjOH was used in the rubber preshycipitant in pInt of H~~O~ the readings were -table l)Ut were not reshyproJutihk The lIl of XuOH in pInel of H 2SO j ran nHittble result as a llth H(HY(Pl WIWll til( li-P(l put lthatgtl in lublltl llnalysis or H~O illlP-ius anal)j wn-i uddint(1 thl eharalteliti(s of till liquid with pleeipitated ruhber or resiu in HI~P(ll-ioll n ren1 on the lpNmiddottroshyphotometel m tololinlPtprfollop(1 it lPgnlal lIlll II~ lxplaiHd on pHgP-I (Sl( figs 11 aIlIIl) Tid made it lloible to outain lEPJOshydlHibll tpnlt nntI (onplt1J1(Jttly till JpqnitPIl tlPgJPP of PJPcljoll
IIWIE(TI 1lt COl~101J)
Jtl thp ItJiPl middotxlwlillltnb hefoJ thtmiddot -1l]YIlIt allll pnmiddotdpitallb had lIptll ptoppJly adjutp(l it l fOllll tIuH till llP or a Ploltiw colloid -wll ltIi1)cJ [ttlJmiddotntl- imlIopl tll lmiddotpro]lIibility of the lPlllt JmUkllly ()Ilt 111 U lput lUlU illlihumiddot tOJllPOlUtl tpHd liglyeol teltlut( - llpanlItly IllmiddotlfP(] to lit til I1m t IHflll lImnnmiddott nftlr tlH filial prOIptlllll WtlP dlvPllill1 tlll 11lIlpfit (If thtmiddot [llltlltin lollohl wa Hot 0 natlv I1l(lhmiddotd III rlumiddot Ia- of tmiddot ill tllmiddottJmillaritlu it b [1 hmiddotjlmiddot til IIpoundgt Ir llH1 It liltr ill-llImiddottiT Ina lll ptlPII by it U( in ruhhfl mmly j 11If dtmiddottail fOJ tltt lllllmtlllll If thl plot pet in nlloid ~llntill tltlmiddotlImiddotmiddotlttlatiflll lIOlllllllhtiPI1 are iPllllll page
liTFHFEHliG COIOf
(hi II tht lllail 11111111111 that had til ill -111111 II urklll) om tlH method fot lublJtt tlIlO1 rpir- nlalv~i in plaut llllpll- wa ttl (lilll~ inare tIte (gt1[01 till to tIll ptP-PlHt f xi [aIWIIII- 111 TIlt amount of (olor varip from lUllIt tn -amp ]pplwHlI nlt rhmiddot lt IIf thE Hl(ltllial tllP part of till plllIt -lI11lhmiddot(l tilt hi-tlllY f tlll plaut mtteshyrial ~ub-lltInent to Itlllmiddotnmiddot-rill lliI 1011middotly OrllPI Inlw
In ruhlwr lrtl-i I Iii 1101 au Itmiddot 1Iplll11l by 111[ I--r ratmiddottilt thE -lllll]t with uptoIw or 1middotmiddotlIll-ol - wIdell [llllol- rlll loillriu nutttel autI thtmiddot lpill- Thi- howmiddotvt n(tnll- til lXtla -11gt1 ilt prlJ~edun) In lP-ill ltluay-i nllHufldy tlW[t j 11 1 1IO(PIlln fill the 11shylImya of hlulophyll Hwl rIlI-r middotIOII IHlttlmiddotJ dlH lUtl~ In plltIH withoUt alo aiftIriL till nmiddot ulttrll
111 pllIbIll1l Wi tilmiddotr hId h It-ImiddottHI tht Pltlpll 1 hlitlt lilt tlw tulllWlli tollImiddot uIwltllIIntut -lltUIhorlllllltll 1111 tIll tlettlllliIttwr IIf t 111 lWlrl-Uamiddot of bdt tl11blLlittUhmiddot r [1 tItmiddot preshyj
lipitatifll 1lJ llllllWI atbull 1iI- in III -1nrmiddottIi fHlttalldh nlrillU~ amount rf middotlorilig lIUlttll Iii lhll of ih lltmiddottllllhottohttt~l l~ol()r infrtl Hm II upd 1 rwmiddot tld~middottilmiddottll PlllItlhi~ f it j proYitiltl with tIll lilP--UlY tU(jlIdlllIlml tIltmiddotmiddot lllklllUIlI
EIECTIol OF 1 [EGTH~
-Ptfmiddott ral tracilull ru~lI gtIll fr 1 nllb t ~xtltd 1 lIlt-th vI iobmy1 ketommiddot lWtl rill [ Ixt lttltt ll UttollylaIiIitt1l11I1t~ ~-I itoiu YtHil)u~ typp of ~IHaylllt f i lItmiddot art hraquoil ill fio1ll1 ~l Th~ lp-nlt fill I11oohl uio[1t ttl willlr til tltN- fur rht IUiXtIUt iwliutll
100
22 TECHNICAL BULLErIN 920 U S DEP1
90 bull eo
I shyz 70LLI 0 a LLI a 60
LLI 0 50 z
a ENTIRE 2-MONTH-OLD PLANTS~ 40 b ROOTS AND BRANCHES OF ~ 3-TO 4-YEAR-OLD PLANTSen z WITH LEAVES REMOVED ex 30 a C CURRENT-SEASON GROWTH OF l- )-TO 4-YEAR-OLD PLANTS
20 WITH LEAVES REMOVED
d LEAVES FROM 3-TO 4-VEAR-OLD PLANTS
10 A
0
a Cd 100
b bull
10
80
I-Z 70LLI 0 a LLI 60a
LLI 0 50 z ex I shy 40 ~ en z ltI 30 a I shy
20
10 B
o~__~__~__~~--~--~--~--~----~--~--~ bull350 400 450 500 550 600 650 700 750 BOO 850
WAVE LENGTH lM~)
FJGcm O-Sll((middotlllll tramaniW1IHl (mrpS f(JI (xlmll 11011 n J1ll of jlta)nle tissur ill n 2--m1 Y011111P of (A) Illrthyl ji1I1J1ltsl krtonp 1111(1 (ll) nt(middottQnyla(umiddot tClIc-C(l1osuln a-i
bull
bull
bull
RAPID PHOTOlIElRIC DETEH-UXATroX OF ntBHEIl AXD HEstxs 23
ThE dula Pl(S(l1t(lltl indi(ntp Ihut 101 Illp ulimls llHthyl liohutyl htOlIl (lxtrHts (lI(I r(dolls of Il1Hxi11111III nigtol]gttioll wiH1I all (is-lIb 11 cOllsic1(]((l n1( blhn(11 wn ( ItIl( Its lIO to () I1It~ nlid Ii to Iii mJL
WhllNIS tlw I(gions of 1middottnL(s( light 1lnlllittamp al(l lgtPlW(PIl wan Ipllgtltsnr) to Ii nllt jW) 1I1JL nlld alio Silllill1l 111l1b (n SI(lIlId 101 nc(ton ]altmiddot(fmiddotollp-(llloolp ~ pxt Ill of 11a 1111 t illl TIl( (1101 du( to lolo ill tlw litlltitl a 1Il1 lullll(I tH lPill- hanmiddot bpllI PI(_ ipitated ma he 1((I1((d to fltI ynbhing poillt II ph( illg OJ illshylmiddotJall(( WIWp balld nhm ()) IIIJ1bullbull[1I111 lxjlPIitllll1b Illln -h()1 that Ih( lIIot uilahl( WHYI lHlIJ fOI 1-1 ill 1l11J1l(I HIH11Pill- illllllrsi i-in till IlPighl)()lllll()(l of ~llIl1lt bull
bull UIlIilHlIy of n typhn] lXPllillllllt to )10 l1iP(tiP ((JIlllo( of (ItOIS dul to lOIOl in 1llblnI Hnd Iill xtnumiddott 11(11 IIIIolp t jUl i p1llelll((l ill tub]lL Till llhlllt- 1tpIO]II Hnd ((llll~()h whit-h UI(I ](]Hllilltl n 1I01lllIhb1 01(111 lxt 11111 IIll 1llll)1 nmtp[in I and )(middotills Tid IIlnkl it poiblp nftlI tlIp uplll1tillll or tlll o1PIl( (0 [niH lip 1Iidl1p~ of lI111 11111(( ill lit ll11l1)[1 (llnlIb nlld Ihll
Sl(ll n ol1lliOI with tllP olnl IJllt illiollt HIl Iltlllll llllI (Ill ltllthpl prpipitnnt j Ihll1 nddld OUI ha a lIilPt lP( of till lIiciPlw of WH( lllIgth 7) lUI- ill llilllillatiu (nnl till tll Ixtll1I101l ()lll~
Tuu tmiddot-Elilll IJl flrldillY 11-1111 lrlllI IjfJI til islII 1 1(1 ([rllt IIIIIJIlIr JiIlIt~ if 1Il( Ihll 111111 k til I III Ilrln I 1Intd tf 11111 JiSf fill I I II I tIII Ilf Iilltl 1f1JlIIillII1f I Till 1[ 1 IId 1 (I (middotIt 11111 (I1I1iI1 1lf1IWtlfJlIIllfflr p middottrllhIJ11 II J III 7IImiddotIa 111 111 lilt jJIp 111 wilTII
t~t tnVIli~ ~nn r kn t~ i tmiddot ~~l Jr 1middotmt ltlTt
HmiddotOtt ~I~ lin t I ~ 1 t~~l ~qrmiddotthtmiddotrtwb
Hult-middottltlru t T Hw ullut rHtt~ r II I ~ PH~lllt
A~tmiddottHHjmiddott~rjd rl ~gtllh 1 tn~th~ ~ ~ middotI lt~ b w bull hmiddotth~ 1i~lIhun 1 Ii tnl Illd1 -11lt1(11i lullI lUI tJl ll~ t1~11n( I Ihan1li flfttIJir Ult I Uuhtltt ahuul l(hmiddottHmiddot~t trv r fti HIt lftbyl tlonhUt)1 k_hIl( 2 m~ fmiddotf tuhlHmiddotr In mlth~ llmiddotlf- 1 t r
t r_~ t j
Arhlitlltd ~llIIDHl NcWitn1 ( Ar-(lt()nc~middotttrrtrt ritJJI~ -Iu nllJtl4-middotr
ACtmiddottflnp fmiddotxtrn( ~ T-P511ftf tn mtmiddotth~ 1 ~difmiddotut~ kdn 2 nltt ulruhhtr in Un-tIl lltbu )J~IYt
rUth(Hl~hltlft HhubU
Illlh(I(t tttUtUt hUbtl til J ~jlitl(J Hilllll trtIIImiddotjtl1ll
(UShl I ~tlO wHllolH rulh r (middot1111$0]( J~rru t t )lthyl 15bullbull1middot1101 klll1l
Ili( UHUicbcul ~((i1rUtl ~ulu1iin 1middot lIUIll Ilti lrllltlllt I Ruhhr llt1thuI r1 -1 Irld
ltlt1111Sh 2 nuz f)rruhl~rm nlith~l tu- h f nt nil~middothgt(H] tlrlftmiddot 9lUtirtl middot1 1
rlcltfl( H(l dnllltml it
(IISllhH~rI( Iultruhtr CII05 1v ltTlft I 2 UI~r ublwr In llldh I hlt~1 11) lgtjdvr(llsl~9rlltmiddot middotlmin ~ I~ gt AIHItilltl no IrttipHallr iI
~ Bbnk 10ol m(thyl i~tmiddotut~i kdHn H 1 m1 j~~ l1rH-t lt~tlfltmiddotn sf n it ll HltlMjftr~nol O2~mlJ ~U~1o-ulp ti~tW -xtra~middotl(lt1 ltt 411 ml bull ie f Ct- kft rt t~ tirattJ middott ill r u l1kn ttJt
in metltl isobutyl kNqnf nn~i mljp ur tmiddotmiddot ~oml ~urr tttl i t w ltJj1JH kt 4t 3 nlank 1 mL((l1t~rthmiddot(middot mI mttr~ ~but a kmiddot tmiddotc d 11 ~ gtli~b~ hifIAft- fl~ lL lnti 149
ml8(dlfilll BO bull 02 gm guayule U$Stl(middot xUlClt-l tf(h tft wI n nmiddotmiddotmiddotlgt 1 lznt on tmiddot ~Jt r~1 ~~u~~ H~ iI~ thT
24 l$CHNlQAL BULLETlN l20l S DJltJPT OF AGHl(CLlOHJltJ
In table a is pl(sentc(l such c1il((t edlt1tIHC showing that thc (0101 Ixtrnetccl from guaYIIle tisslIe wit h II(P(OIl( n nd (pl1oso[yc is cll(div(ly sCIe(nec1 out by the s(lp(tion or wnw length )0 miL Oil t1w SI)((IOshyphotonwtpl This tnb]p all-HI ihos thai thl Juhlwl altl(l((1 (nn IJl quall shytitntivcly 1(I(()(Ipltl in tIlt PI(ilIH( or Ih (o]OIplnwPIials and Illsins and tlmt Iuhb(l WtlS nppnlllltly 1I0t (xtltI(((1 110111 11l glll1I1l lisslIt b~ tlHSP SOhlllts Thls( ((suIts ginmiddot (OliIHillg (idJt(( that t Iw IISI of waYl llngth i)ll 1Il) OIl till SppdTophot OIllltPI ii t hl 1101(1 p(oshy(ellule in photolllliTie IlIlalysis of luhhlI OJ l(sin-
SELEGTIO- OF )IOiOCUHO)IAIIC ItIIm ((1111110
On th( basis of th( IPHIlb shoWIl in tabl(l 1 al hlllpls (1( IIln(lp to SPCtl lC the PIO]Wl 11101lO(lIOl1ln til Ii ltlJ ((lIllIJi nIl ions 10 llIiOlS (oIOlimet(Is 111(gt 7W-Ill~ filtpl flllnhwd 101 til( I1~lI1l photoshyplpct1i( (o]oriJl1ltll fol which Ill( (hlll(IlIiitit~ oj t hl Ilda he light ilUIlBlIIhiSioll (t) elll nn -hO11 ill fig1lle 10 iws satlsfa(lolY IPshysultl 111( iiO-mL HitlI olllhintioll 101 whkh ttp (middotIatinmiddot light tlnnsmission (ullmiddotis a 1-0 showlI ill figllll (I is -nthdnlto1 hut this is not stnlHlnld NtllipmPlli
Up to fhl PlPHllt lIS(middotflll pound11((1 (ulllbinntions jn lltl iOO-I11L Iunge hayc nol bllll SlClIlld 101 lhp Klpt 1-1I1l1I11PISOIl (olOlinwtll bu fnltlwl nttCl1lpti 1( )(illg IlIHd
TJIpound OF ST~lmW AFTEH HIIJ1EII Oil HHSIS rlll~CIIITTI(J
~ considl1ltiol1 of ttp lillll of Inlllling af((1 plpeipital ion of 111gt)(1
01 l(sinSTlOIll ollltionis impoltant J(jl~ thC1HI(Plltngp of light IInIlSshy
11 rshy10 f shy
09 f shy ~750 Mil- DOMINANTI
~ 08 cshy I WAVE LENGTH z
I III III i O7 - I III
~06 - 05 shyw
a
Igti= 04 - 720 Mp DOMINANT ct WAVE LENGTH- ~ 03shy
02 f shy
01 t shy 1)O~~~gt~- J 600 700 800 900
WAVE LENGTH (Mp
bull
bull
bullFIGlRt IO- COJllPIUlItiw ~IW(middottltll tlnIlRlllii-lion (II (IllP( 101 1i11(1 olllhinulloll
with dominllnl Il(lllllgths at 720 and 7iO lUi
bull
bull
bull
HAPlD PHQTQlfE1IUC JjETER~lINATION OF Rnmrm AND HEtiINi 25
mitted (spertrophotoll1eleL lCuding-) Ol light (1 (tClcrl (phOlOshyJluol01l1et(L lcndillg~) i~ StlhjNl to (hangl
]fjt~l1le 11 and l~ show that ill til( (asc ot tJaugtIllitteltllight llJHC th~ (x[llliHlllIlnl (oIHlitiOllS tllpl j lilst n dtlln-e ill Pll~(lltngl or UllllslllittnlH( follrnY(l by It ptJiml of lClntin stability with only sliuht (1111 tHn- a f(Pl a lIt1ll1btJ of minutes The light t UIllllitblllll t l(1 ill(Iln~(s This lIIay IJP llllllJltlli7P(ll1 ffl II ow 1Ilt )( f(( darI oliIII tIIlIlNlIlitt(IIIlfJIIlh (iditilIiid Ilil1 pllIipintnl )uoshyIn Of ( 8inx in (~f1( I~iUII i~ Ild stahl I 11 itlll If 1inl nh prlshyilli(ioll of 11l1d(1 II IJIX f) jllIli II (fJJltfiIIlilty slllMI IIriot 1) IIIPldUnl1i tll(I1I rllltltilJl oj tJi~ Jlt jiot IUN ilUf Jxl1 will tIt( tOWI IItlllilil I 1llIlllblJIol I ill I~11l11111 d ill till ifjuids JjOI scnttplltl light 011 till phololltHJIOIl1lttl till dilPCt ion 01 elangl b tlw IPrfIi (If that illrli(atPll rOl tlulll1Jittp(lliuht It Itlll b( llluliJr I-(Pll that if l(middotndlnJ- IIIP mad n itl I t lIP ~()ll1d()lb lpalll this pllioJ of nmiddotlatirp tuigtility tllP llLot tIOllt thi Olll(P (nil bl IPdUCld to tIl lltini III 11 Ill TIll l~adiltg (illH~ bbll Oil tlHl datn rUl lublwls and llsinlt Illl ginll ill tnhh
50 r----------------------------------------------- f shyZ
~ 40 ~----~W~A~V~E~LE~N~G~T~H~7~5~0~M~P~~~~ ~ --------------------=-=-= ~ 30 f- WAVE LENGTH 540 M~ _z _____ ___ -=- __ _ ~ ------shyt ~_=---=-=--I GUAYULEIII 20 -Z HEVEA ltt II KOK-SAGHYZ f shy
4 6 8 10 12 14 (6 18 20 22 24 26 28 30 STANDING TIME (MINUTES)
FIlirtn 11 Emmiddot of wav hll~rh Il li~ltr tlall~lIIit1alHl aftI IUIlItHt -Imlli lug 111m for guaynh llmiddotn 011111 middotiolIlJh~z 1111111 llijlitul1 flolll 1lHlh~ll1Jllryl k11II11l ~(lilltlll h~ lwitlitll 111Inu1 111l~1It1 2)1111 o1U11111 (Helillins on (illllun tlunhll IlIIJlllw]ntllW111 lutl(I[lholtllllltlt with ijUjt Wlnl IHI Ilf1 I
11 EFFEGT OF Hbli 1 -()JXT10~
Tilt lnblwl ~()h(llh pxtnl( till IPillgt ubo It 1m nllu1- bellt -~atea thut ~lll 11-111- tUP olnbhmiddot ill middottIIlIlOl ~1It tlWIIJI( my U)t PIl (tlIHatcl WIth tl1l lullh(t I tahle lJ 1hln 1- -1111 tIll (llllstlOll of nny p()~iblt tITptt of XtIIl11 diflp]lws ill ((JlllPllttUliollS of 1l-in lil lolutioll alollJ with till 1lIltbpl TIU data ill wbh +ho on tIl( hn~is of (olorilllPill ladillU thaI tll( IIUOIl1t of lnbbll Plllipirntld 110111 Ilwthyl olnlld kptOlll olntioll IJ 1li-jHlllnt 1l)04 in 1-llltlIllt ethallol)- not amlll hy thl llllNlI(l of llvin aU1ouut of llins inolution bull
-----
26 rECHNICAL BULLEfiN 920 U S DEPl OF AGRICULlUHE
100
90
80(I) C)
z Ci 70 UI a 0 60 a ~ UI ~ 500 ~ 0 I Il 40
30
A 20
0
100
90
(I) 80 C)
z Ci 70 UI a 0
60a ~ UI E 0 50 ~ 0 I Il
4-0
30
B 20
0
--
--shy ---shy---
2 4 6 6 10 12 14 16
---shy= ~ ~ shy
-
2
025 05
10
15
20
25 -30
35 40
SO
-60
=70 80
16 20 2224 26 26 30
OS
- 10
IS
20
2S
30
35 40
-50
-60 -70 -80
bull MGPE 25-ML
VOLUME
bull
MGPER 25-ML VOLUME
Florm 12-EtTld (If till1l or Slllldill~ 011 light transmittallce (01 (A) gUllyulc lnUIl(I plccipitllitd frOIll llltt h~l isobutyl Ielollt solution Ily neidilic(l ethanul bull null (B) gUllyule ll~illii pre(ipitated flom aeltoll~lllcetOlll-Cl])osolY( 3-7 solushy11011 by H(illilip(i l1U (HPlldillg~ nt -lIlillult Ifllpluls 011 Evelyn photoelectric colorimellr with jU-lllp tlllll alit U-1I11 npN(lle spp also table 2)
bull
bull
RAPID PI-IOlOMEllUC DElEnMINAlION OF RUBBER AND RESINS 27
TADIbullbull ] 4-ReZation of amiddotmount of middottbber pleeipitate(Z Oln metltlIL isobutyl ketone 80lutions by OS-pereent H 2SO in 95-pere(lIIt ethanol to umollnt of resin8 udde(l U8 indivute(Z by colorimetrio readinU8
(Rubber ami resins cnlculntcd on bnsis of amounts in 5middotml ullquuts of extract from 02 gm of tissue in a 2fllll olumo( bull
Hubucl r~cocrell whcll rcsins nddcd as IndIcated Htbbor al1dcd (pllcollt) ---shy
__________bull_________ ~_12rpcrc~15011crccllt 7511crccnt IOOpcrcent
PerCtllt ercellt Percellt Percellt Percent o o o o o) 50 250 263 252 25000 500 500 500 500 700 750 750 751 749
1200 1250 1250 1250 1250
EXTRACTION TEMPEHATURE AND TIME
Typical experiments to detllmine the time required to secure maxishymum extmction of rubber und ltsills at 115deg U Ilre sUlIlmarized in figule 13 the solvents used-methyl isobutyl ketone for rubber anrl Ilcetonylacetone-cellosolve 3-7 for resins extraction-are very eflicicnt since under the conditions indicttted maximum values were secured after 30 minutes of ext1llction The most eflicient liquid for the bath (lig 1) used in extrtlcting rubber or resins is ~ high-grade cylinder oil (S A E ~O) The sand bath and such liquids as glycerol have proved unsatisfactory
RUBBER AND RESINS STANDARDS
According to the National BULeau of Standards 1-_ lhclc Is no gellcrnlly recoglllz(d standard lIIutcrlul [ior II rubber standard] The rubber hydroCllrbon ill llifferent samples of conmlcrciul smoked sheet or pale crepe from heclI pluntlltions nries from l~ 10 04 llercent of the totul nutletmiddot the most 11Ioruble conditions Of preparation
McPherson () has described a procedure for the pLeparation of pure heve~ (Hevea brasiliensis (H B K) MueH Arg) rubber from crude rubber or latex In the absence howevcr of ~ generally recogshyn12ed stalldard for rubber hydlQcllrbon [caoutchouc (CnHUs) xJ the standard adopted was that of the relnthely pure product secured from gunyule tissue txtractiotl nccording to the Spence-CaldweU method (5) or the motlified PIOCCdUlU of Hohnes lind Haasis (p 2) The details for constructing the calibration CULes are given on page 10 Standard rubber samples apparenl-]y can be stored for a long timc under the conditions des(libed on page 10 The duplicate colorimetric lendings for glULyule rubber newly extracted by the modified SpenceshyCaldwell method were ()J2 ench as compared with US) each for the sample extracted by the same method but stored 1 years In each case colorimeter rcadinllS were made on mixtures containing 2 mg of rubber in It 25-1111 Yolume
The selection of tt suitable standurd for guayule resins presents some dilliculties Tll(~ acetone extract of gUllyult estimated on (l gravishymetric busis~ for instance proved to be variable depending on the type of tissue sampled or season of sumpling because such fractions as
COllllllunlcntion dul(lt1 Octohtr 22 11H3
28 QECHNICAL BULLEQIN 920 U S DEPT OF AGRICTTIIlURE
16~==========================115 shy
14 bulli= 13 z ~ 12
ffi II Q
10 c w 9a w
8gto () 7w a
6a w
5en III ) 4 a
3
2
A 00 5 10 20 30 60 90
14~------------------------------------------- bull13
i= 12 z w II ()
a 10 w Q
9 c w 8 a w 7gt o () 6 w a 5 If)
z 4 If)
w 3 a
2
o+B~~__~__~____________~__________~ 5 10 20 30 60 90
HEATING TIME (111 NUTES)
lllGUltE 13-lDffect of time o( lICntillg O2-gm samples of gunynle tissue with solYlIt nt llfio C on lo(OVl)ry of lllhlJer alld 1Isim Lt HlIhblL extracted with methyl isohntyllwtone B resins Cxtll1cted with aCftonyla(etonc-cellosolve 3-7 bull
chlorophyll are weighed along with the resins in the acetone extruct but are not estimated by the present photometric method (fig 0) 1he use of a diffeJent stanclttrd waS therefore indicated
bull
bull
bull
RAPID PHOTOMETRIC DETERMINATION OF HUBBIm AND HESINS 29
The resins standard selected is based on n relatively pure source of resins the rcsinous exudnte 011 the stems of guuyule plants IJldimishynary expeliments with the resi nouS cxuclate from diffcrellt gllayu Ie strains of various ages indicatc nHlt there is little YaLiation in this subshystance on the basis of Colorimct(r readings 011 2-mg aliqllots of 01shypercent solution in It 2i-ml volume (tabl( li) Expelilll(lnts have shown that the air-dried (xuclate contains 3RtOH p(Ic(nt of -volatile matter This material is l(latiyt~ly stablp ill (OlllpoBition and is npshypurpntly on ly slight ly hygroBcopic as shoWIl ill Ia bl(1 1 Tlrp Ipsinolls exudate may be jJleplpd in two wayi-i fl liSP as a stallClHld-(l) the clpan exudate is clripd iol Ghouls at ()1deg C at W indlPs of a(lIum Hnd aftclbCinOglOund ill a molfalis 1)I(spI((I intn airtight COllilinel OL
(2) tllP Cx7lclate is clissolllt1 ill a(lhllll and filtplpd PlactieaJlyall of the acetm1l is thpn lYapolntwl olt OPI a stlam or atCt hath and Ow residue is dripd ground an(( PI(sPIld as ill tllp fin lllethocl Tlwse two prepalHtlolls a1( (ompalpd in ta hlp ) 111( (((tails fOl ~t()lil1g the resins standald and (onstlllcting the calibration CUITPS alc given Oil page ]2
lAIIIg fi-CUIIIllrsoi (lJ lIr-dr(1I IIIIi 1((11 II II-()I-tr((l l(sil~ 11111111(8 of I II 1111Ie
[Colorimetric rrndill~s 011 1~I11 phulll(Iclrie eolorillJct[lr with i~()middotmll (100- to iiOIIIIl) fillcr [lnd 5-1111 lIperture preeipitantl part ofO5middotPIrctllt 10 to 5 paris of IIOj
nupliclllc(oloritwt([
nIl(lin~s (hIlSlcAg~ ofSlmillXo JrNliltlCllt of fPsiJI$ L1Xtlrlntp on 2 IIIg ofplanls fllsins (XIHIIlt~Jwr 25-1111 vol
tII1(1) 1
leflTs Various _ bull ____ bullbullbullbull 3-9 Colll)Josiltrlairmiddotltlricfl bullbullbull nf)2 002
])0____ bullbullbull _bull __ _ bullbull ~-l Composilld (ri d at n5 C in aUmiddotimh lWUUllJ for l (jOuj(ja hours])0______ bullbullbull __ bull ___ bull 3-0 COJIlpositld disso]NI in neptolll f1l1erNl fl(lf()ll( GGO i(jO (Ivaporntld olT OV(1r Stpl1l11 halh TesidlH drl(ld I1t fi5deg ( ill anmiddotinch VIl(Unlll for 0 houlS bull
middot106 __ bullbull _ Jir~c1rild_~_~_ _~_ ~_~ _ ~ ____ _ __ _ OUu GOifina_~ ~ _ ~~_~ ___ _ _fln~ ~~ ~ ___ ~ __ 6(imiddotI tiliA H)[_ ltlu bullbull i18 tisSflOabullbullbullbull__ bullbullbullbullbullbullbullbull lt10bullbullbull _ tillO llitO406__ bullbull __ bullbull __ bull __ __ lt10_ Utl2 fon591_ fo__ bull liGa oOa 406bullbull _ __ lt10bullbullbull_ li5S OM
j Ph( vnluls in Uw Inst COIUIIlIl indieatp thnt gunyulp fesinous (IIHlnt( wlwtlwr dfircl hi Yn(tlLJ1l1 wilh L~ perc(nt loss of volntllt wutl pr or tWl c1rild giVPd npproxil1lnh1ly t Iw snllw colorinwtCr rNHiing- 011 till busis of aliquot~ cOlllniuiug 2 IJI~ of flsillS lXIHlntp l)tIf 25-mI volultl( Ihil- illdicate~ thl11 Uw UITW IJ1flS~ of olnshytile mntl(f prt~(iJlitnt(d gins npproxilllntlly Uw $1II1l (oiOfirnl1tlf ftudiTlJs ns tho ftsidtw A pnlill1jllaf~middot (XIlltrinllnt indicutls thlli th VUllltill muller l(lIlSists of thl Ilrplne oil fmcl ion I5-(1Il gtnplls or rlsitlOtlS (lxudntll gnvll by stPll1U distillation nn Uefllgl of 011111 of jl(lfPlIW oil with npproximHte tilllsity (If OHIi lind lhus rrprlsll1ll( IlPIJroximllt(I~ 01 Jerccllt Of t he original weight 1hls lllrClnlage complrcs wllh 38 llltrC(ntlost by drvinI( in IICllnllJ
aSplusmnUH perceilt or orlginlll weightlosl
The wailnble illfolJllntioll on tlH (ow-JitlPllts of the gunYllle r(~shyillOllS exudate alld tl1( HeetOlIP ext act of gaylp ti~slw is sllIllmarized in this paragraph lYalttI (u) alld also Hangcn-Slllit lind his coworkshyers 16 reported that 20 percent of the resinolls exudate from gUltyulc stems is parthenyl cinnamaie (CHuOH=CHC020 11JI2r) Steam disshy
15 (OIlIJIIIIUicatioll flom A T Haai(II~l11it llId (0011(11 Calif0111 ill Tnfiitnte of Tccllllology Past(IlIJI Jhps( wOlken al Htud~ing the COTlHlitlllllts of the acetone extract and other conlltituellis of guuyule
30 TECHNICAL BULLETIN 920 U S DEPT OF AGRICULTURE
tillation of similar resinous exudate in the writers laborntory has yielded approximately 4 percent of the whole as the telmiddotpene oir fracshytion Haagen-Smit and his eoorktrs nportec1 thttt about 25 percent of the acetone extract from guayule branches is parthenyl cinnamate and 6 percent of the bark (ltortpamp-phlotm) extraet is parthenyl cinshynamate These workers fm-thcI reported that 25 lwletnt of the nc(shytone extract frolll bLllllches is a compound with the tlI1pilicaL formula CBoH400a 1 percent is a compound llwltillg at 2P to 2T5deg C and 1 percent of the extract from the ]eav(s is tl (olllpoulld nwlting at 100
to 1710 1Valtei (6) reported that 3 to -l perc(nt of the tI(eton( txtract
of leaves and flowering StPIllS of guayulc eonsists of waxlike substances soluble in olgallic soln~nts but insoluble in at(l and (on(ent1llted H 2S04 The flactions mentioned on the basis of (onHLTutle esti shymates of amoullts actually isolated tlecoullted for about H ptIcent of the totalncetollt~ so]ubles extracttd from tll( guuYllle 11 rub The other constituents ltlilaill to be i(](ntifi(d
RUBBER AND RESINS CALIBHATION CVHES
Typical culibndioll Clllves iol Iuhbpl and I(sins bas(d 011 (ldtLminttshytions made nccoLdillg to the plocCdmC outlin(d 011 pages middotb to 1G arc shown in figulPS 5 and 1+ The spCdlopliotoll1lttL en (OIOIjlllctCI readings are plottCd on s(lIlilogalitllllliC pappi ag-ail1st (Il 11IbblI (011shy
100 ~ 90
80 ~ 70 ~
z 1amp1 0 II 1amp1 IL
1amp1 0 Z
60
50
40 ~ltI 30 ~ en z ~ ltI II ~ 20 C) ~ oJ
10 o 2 3 4 5 6 7 8 9 10
RU8BER IN 25-ML VOLUME (MG)
bull
bull
bull FI(lURE 14--Ctlihration curve fotmiddot gllftYlIlc lubb01 (Hct(lings Oil COIPIIHlII tlOl1hl(
monochromator SlCClrophotolllet(r with 7fiO-11IL Illtel alld Hllp Wll ( IHlll()
bull
bull
bull
RAPID PHOTOMETRIC DETE~MINATION OF RUBBER AND RESINS 3]
centrations From a casual inspection of these CUlTes it would appeltr that Beers law does not hold Actual tests indicitted that Beers law was applicable only within a narrow range in the upper portion of the curves The analyticlil results on the basis of photornetric readings nre therefore calculated by direct reference to calibration curves or from reference tables of equivalent values bllscd on the cnlibllltion curves
Calibration curves for kok-saghyz alld heyea lI11tulltl rubbers and Buna S (GR-S Chem Gum IV Goodyear) and butyl (GR-I Standshyard Oil Co Protoc) sYJlthetic rubbers are hOWllil1 figure 15 The samples of kok-saghyz rubber were furnished by the Diyision of Rubshy
100
90 ~I) ()
z 0
1amp1 a
~ a
80
70
60
s 1amp1 ~ ~ 0 ~ KOj-SAGHYZ 0 l Il
50
HEVEA~ ~
40
100
90
~ 0 80z Q 70a Co)
a 60 ~ 0 0 x 50Il
40 ~----~~----~------~------~------~--~ o 2 3 4 5
RUBBER IN 25-ML VOLUME(MG)
FmUIlE 15-CaJiblation curves fOl kok-snghyz h(YCII Bunn S lind butyl rubb~ls (Readings on gy((yn photoelectric colorimeter with i20-lIIp filtpl and 6-ml aperture)
32 TECHNICAl BUIJLETIN [)20) 1 S DEP1 OF AGrnCUIlfURE
Iwt Plant JIl(I~t ignlioll of thi BlII(un and (1( l))(parcd according to 11( SPltI1((-Culd (]] (6) PIO(((lllll Hlpt pal( CLPPe was (xtmch(L with acetone blI()Ieit W 1I(gt(11l a ttnlldal(l
SEXSlllVllY Ol~ llETJIonS
By lip pIO((l(II11P olltlillP(l 011 ]Hlg( +n Iowa (lOOl IIIg (11 1111i(l0shygmm (gHlllllla) of 1hblI ill a 2)1111 yoltll1ll (all )(gt dltpltld Oil tltl Col(man (lohlP mOIlWhlOl1lHlOl l-I)((t 101 l1lOt 0111 ci( I ill1ilnlly 001 mg of Iublwr ill a 2J-1ll1 n]ulllP Illay bl Ilad Oil till EnI)1I photoshyllectlie (O]oLillllt(I Thll ya lllll- 011 tilt IHl-i- (J I (xl ad iOI1 fmlll 02 gill of til-lI tH(JI(lillg to tllP -lllndal(l jll()(pdull 1(PIPStlIt IlO()2J tlnd 002) P(IT(lIt of llIbl1ll IPI)(((inly bull1t1lollgh -lI1t low allils can be d((d(middot(1 il lIoullt1 Ill IPtllizpd thnt till PIIOl ill PlI(Plltng( or tll( al110unt dltlIllIilll(J i ltlatlpl high ill tili PIY lo Itlllgl 111 aetllllllladie(middot Ill( lopl lillliL 111)(1(1 lIw (ollllil ions of tlil ]lI()(lltlIIIl u ol1tlinpd ipt at l11 11I1 or 1111gt11(1 illt i-1ll1 Ollllll IlPIPltPlltillg 01 p(gtl(pnt of JllUiJtL un tlll 1Hli or (xlla ion rlOI11 II rlll of tisSIll
EIlIlOH COSIIlIHIIO
In Oldpl to H(IIp ill )1lHtPltt pl((iioll illlpIi1I- it i lH((SSHI to slnlldHIdiz(i rigidly 111( Pl()((dlll( 0 illdi(ntpd Oil pnglt- - to J( If lids i dOlH tlip lXIHlinwnlal PIIll is t(middotdllld 10 n ndninlllill
Illlt pl(iioll of (hI ]lIPPllt 1IHllwd Oil til basi of ]llllP llIllJt1 alld Ipsinssollltions call hI jlldgl(J 110111 figllll Hi lileh lio- til HPIlIgl d(intioll oft -illgIP lI1lnSIlIlIIIlnt in lHi((lltagl of Ill( alllOllllt 01 Illhshy1)() 01 lpsins d((PI1I1 iJlld TIl( (1101 PlI(Plltaglt H1( gi (1 101 OJ) to
RUBBER IN 25-ML VOLUMEMG) 004 01 02 03 04
i= I I IZCtOW
fbA ICtU CtCt WW a
01 02 03 04 05 06 07 08 09 100 = RUBBER (PERCENT)
RUBBER IN 25-ML VOLUME (MG) 10 20 30
~ I CtZ
bBOw Ctu CtCt Ww o I~
010 50 100 150 200 250 RUBBER (PERCENT)
RESINS IN 25-ML VOLUME(MG) 10__ __3-0_ 40 50 60 70 60 90 100--_-- 2_-0
Ct~ -r- 1 I OZ
WCt UCt b C wCtW
a o I I 150 250
RESINS (PERCENT) o 10 50 100 200
bllI 1tI W-Yllnl dtd1 ioll I I 11l1 11IlI11 1(111(11 1 III Plll- IlIIIlol1 01 IIim~
bull
bull
bull solution Il basis J o golH of tiSSII (JlILCl-nt (11(11) for (~I) (l)1 til O 1I1
of luhllpl lin 1 III I (I Ill of lUhlJPl nllll laquo I J to 111 nlg of IlSlllgt (Itllillgs on ]iYllyu pllolwh-llrk CO[IJlilll(-(PI with nOHIP Iiltlr lIntl U-lIll allcrture)
RAPID PHOTOlJElRIC DELEHlllNAllON Cn HUBBER AND H1~SINS 33
10 mg of rubber anel1 to 10 mg of resins in a gJ-m1 yolumC For
bull
bull
bull
comparative ptuposes the leslllts arc also calculated on the basis oJvershycentage rubber OL tltsills in 02 gllI of tissul As WOlllL be expcet(d the error increases sOIlHgthlf for 1(lali nmiddotly low COlHell t1llf iOlls oj rllbbeL or resins The curves in figure 1(j s1l0 that ill til(gt Illlge Ol to 10 pCrshyeent of lubber the elTOI rangts Jroll1 abollt Ll to II) ]IlC(lIt abo(~ this mlllc tIlt (ITOl d(((ts(s to (ollsidlItbly ltmiddotss (han 1 1lICPllt of tlH mllollnt ltl((Lmill(d Hil1lilally in tlH (lISl of l(sins analysis (fig 10) the ltLTor is (onsit1eIubly INS than 1 PlLllnt ill (he lallgp of 11 t~) ~() penPII t
In nil ([lSl of lllhblI alld (sins lx(Inltpd tIOIl1 (issups Ol addcltl to tisslle lxtlads (s(( tabhmiddots (i H) illyolillg ll01P o(lllntiolls the eLI01
is hig]wl thun that indilHtld in figllll ((j Im pUIl Ill )])p I tllllllsins solutlOII
COlllUCIIOXFOH IXSOLl-IlLl~ Ilgsqgt(Jg
111 th( Jllo(pdulP ollllillPd 011 paw I till illsolllhll isSII Ipidll( tflpl (xttlw(ioll is (Ptill tlw lIask l(lll till xtlct i l1wdp up to yoltlllH It is not rOllPllipnt (0 IPt()PI qWlIltitati(Ir III(lw[olH a 11(1 pllooll extlnlfs of guuyull I is-lll alll thl1l main t11l111 up (0 YOIUllllmiddot bpCaUHI sllch all additiollal stltp wottld]) tillll-C(JllS11ll1illg Th( Iogiea nll(gtIshynntin is to mnkp tltl lXtlUCt Llld Ipsidup lip to OllillH in till original flask andi llPSStllY 10 llwlno tl OIIpdioll wlHIl (allIlnting [hc llshy
Hults f(JI [hl oll111lC displupd hy till ins()lllbh llsidll( III it l)picat (IXpednHllt (ollsisting of Jhp lppJiea(iolls if was Iollnd llftt at ~iiO ( 02 gill 01 Iuhhll pillS IPill-fl(( lisslI(gt (lollpdll fot llwistUlC ou basis of dlyillp ut lOW 101 ) llOlll-j (lbp(ld only t~ llllUll voiul11P of OOk7D~- OO(lOO(i Ill of lllthyl bolnl(yl 1lIOll( (lplhlli(al-t(Tnltle sp gl () Ii I ll(Hli (j at ~)) -gtitllP tl1(gt 1It101111( () r t is-lIl xt Iadld j sl1lall til( PlIOI dul to Ill(gt insoll1blp Ip~idll is slllall III [0111 ill( wOtk it (all lJp diIpgal(ll(l
]hcon~lIY OF HllIllgl AiO HESIS AIH)gl) TO EXTlIACI OP
GlYlLE TISSlg
Tnl)ll G L(IHpslntillp (ypi(nl llld(~ SllOS (hat all a plngl of HIOK PlI((nt ot lltl pltl( Ilhl)(l acldpd to tllP Itll h iolJut1 InmiddottcJllP xhnet
of guayulp tiSI1( WllS 1l((PllIl Tlli nllintioll flOlll (olllplpU I((OYshy
PIY i within flll pxp(IiIlHuttllIIOI ~illli]llly fnbll Ii llows thn 1111 llYlIUgl of 1O(1~ ])(I(Pllt of gllllYllII 1(-i1l- add(d to II( (pllosol( (xshytrae of IUllY]l t i~HI Is 1l(oPIPI
THl~ (~ Hf (Off Ill of 1111)( J OJ I~il~ lItfI(( In ~(JI1IJk~ Ilf (111 [lI1Il fI2 lIII
0 tlUfllllit i~~I1
Instrument
---- ----~---- bull shy 1(1
Colemun ruono~ltrOUlllt()r 2t) II sJl~ctroJlhOL()lIIeter with 2tJ I iflllllI wnclength Fetting 21 II nntl 0-1111 WU HI hUJl(L _ L U
Ill 7Evolyn photo~lcclrie (olor JU [ imctcr with iO-llIl filler IV (I
H1 0 t I I
llImiddot lUn WII 1011 HIO Wn mil lUulon
10 JIg1111 IUI ml lUl anh Io aLn 111)_I ) III li lU It 2) deg wn2SU DD
Irl JIll II IIr II US II
1110(1 lULa lUI IlK) IJ WU
I( llI Htl tNI 1(111 2tlNI HI 0 221) lllil t2S 0 1~ 10 1~13
In (I 2117 I
10U 1l(J ~ 4 _H_j ___
9middotJIlJ5 10115 10 00 lUU5 flUU 4li (tl03 9(11)
leIlKl 1l~)5 lOOU l1KIr JOIS un 003 OIl Ii
34 lECHNlCAL BULLErIN 920 U S DEPT OF AGRICULlURE
COMPARISON OF PHOTOMETRIC A1D MODJIoIED SPENCE-CALDWfLL METHODS OF RUBBER ANALYSIS
Guayule samples were analyzed by the photQ111etIic method and by bull the modified Spenc(gt-Cnldwell mcthod The values in table 7 represhyselltativ(I of typical results indieate It -atisfactory dcglpe of conformshyjty between the two methods in thl range of tiSSlHH with llHHC than OJ) percent of rubbtImiddot On the bnsis of the amounts determimd the results in this runge for the plmiddotts(nt lIlcthod ayernge apploxinHltely j percent highcr
~LAIII~ 7-(oIllJl(i~on of lltlllrIic (IIri mOtllinl SJl(II(r-(ulri-wall IIIrtlwrl~ of rlrrlIIillillfl 11)1)(1 COIIrll of UI(III
1 Flowers frllm amiddotmonth-oltl nursery plants
YAIIIATJO- OF SIli(LE DETEnt1NATIONS Fnoll TnEIIllIEAN
Rllbbel (Uall8i8-Thc plcCision of thc pLcsent method when gunyule tissues Hr( nnnlyz((1 for rubber may be j udg(d flom I Ill datil presentcd in table H TIl(se dahl -how that thl pplCPlltag( uriation of single determinatiom from nwan yullles with low standllrd enolS ranges from less than 1 to 4 p(gtrlent
R(8in~ wWlsi-r-s lndi(a((1 011 page ~j he INntlts s((uled hy the present phoolllttric nsins llHt hod are not tliltly (olllpalable with those of the grtLVimetri( ncetol1l-cxtlt1(tioll II1etho(l Thjs made it necesSllry to selc(t another lalibllltion staudud-tlll Ipsinous exullate from gullyule shrub-thut gies relatively COllstlllt photometric readshyings (table 5) The resin (olltents of guayule roots branchcs or leavcs usually ran(~e from about) to 1-1middot pelcellt The ple(ision of the present methotf WhCll gUHyule thslllS lIe analyzed for reins may be judged from the datalHmiddotpscllted ill table 9 1h(se data show that the p(lcelltage variatiun of sillgle lhmiddott(Lminntions iLO11 meun ynlnes with low standard NTOrs rangcs from about 05 to 4 percent
bull
bull
bull
bull
bull
RAPID PHOTOMETHIC DElEruIINAlION OJ RUBBEH AND HESINS 35
IAIILE 8-luriation inclieute rubller (mallSM of [1wIIle tissue bll thc 1111O0Illclc metwII
Vnrlntlon~Ilbher I (rom mean
ierCtnl Percelll ~OU -22 ~ 25 +27 ~ 20 +18 ~UO -22---------1_______ 51110 0G6 bullbullbullbullbullbull _bullbull
10 ro ----=ii41075 -01 1000 +11 1010 +13
rlln HI itil 1l9~ 1_ ___ =-~~~
115511 ~ US -111 III II 1575 -13 115 b tiS -I a 111 h WlU +22IIM-(middot bull 11K -1Ja Illi c 1000 +03 1J5H1 W +l)7 ll1imiddot tl 1575 -13
Mcnn 15951 131
1102-11 21fJ() +21l102-h _ ~~)SO -17 1102-c bullbull 21CO +21n02middotd ~OIiO -26
2 r~plusmn Il~ 21151 261 I -~-------bull---__ _~~_~______l-___--_
1 lhe$ 1111($ I1n (or SlIlIIllltS Stpnnltplr PHrilClld IIrtlrdlng 10 1hr prollIlIlr( OIiIIiIl(o(I on Imgt$ 4 to IC ~tcond nUlI1 hlr r(J)[ltnts stl1ndnnl llrrot of tilt 1I1(1111
1_1l1~ n-J(lri(iot in relli(Upound rpoundsins (lllalIsfs of VIOJII( lixsue b1 the lhomillric lII(lloli
-- ---~--- - __-------- shybull I I I I Varlgttton
_________~___ ~~lu_n_Jl_Q_~~~_____ ______I__~_o~S_J frOID lDean
Percent Percentgt458-1 ~65 +41IWtl-li 130 -a2Hli8c aliO +26S41i8-d bull 130 -32
1(-011 34I10Olifgt __ bullbull __ ~--====
li-9~2n 881) -06 li-9~2-b Si5 o ~HH2middot(middot S i5 -6$-H2middotd 000 +1
8851 054
O i5 +6 9 i5 +6 950 -20 U75 +6
H-liG3o-n bull -1 n-li6~b bull __ _ -IH-IWH +4H-l61511 bull -1
1tmiddottlU
62~-lI __ 62~-b ij24-( bull OH-Ji
(-Ull
I rll(St oluls nre tor separately ~xlrflCled SllllllllCS IlctOrdlug lO procedure outllned ou pages 4 to 10 i Secoud number r~prtgeulS stulldMd error of lIe menn
36 TECHNICAL BULLETIN 920 t ~ DEPT OF A(]RICCLTCRE
ReUUER A~ALYSrS I~ CRCOE-RcuUER PROOCCTS
Sew rapid photometric m(lthod~fol the ddellllinttion of rubber and reii Hi ill uaYllp ti--ut htp lllell pIPHnl pd oil pag( ~l to In A brief H1111111tlY of It similar rnpid llHthod fm 1I1hb~rllnltlysis of u1lulcanizNl tlIldp lubbll pl(Hlmtlt whielt i~ bn-(tldo on the prill o
ciples dehtilcd tlllLe follows Duplltate nt-gm sllmph of the finely cliyiliNl IlInttlitiup wlirllll out [~ei-()l (all hl lIf((tinmiddotjv INd to lt1iyidl till alllpl) TIll kltolll-olubll portion of till )111(11( tlrc di-olved a- indh-Htpd fot thmiddot lllnkill~ of -tlllHlunlluhhll olutiou Oil Pt 1II hut tIl IUlIp Hn lIn l-fplImiddotd 10 lHI-ml rolllllltti( fln-k antil1ltld(lup to Olllll1l The bnlulUp or till JllO(ldllll i- thatutlilllll on paWs -1- 1 IHI Ii 111( 1(111 1- nIP IXPIP--pd nil til IHi or Iw oligiJla w(lullt of I Ill (I11l1p-I1l11Ilt1 1)(0(11(1
Hupitl PlllimiPJojgtiWllllllllh llIltllOd~ fOJ Ihl llPtlmiddotminntion of ImiddotUlJbll tlnd 1(-illo- ill -111111 Illllph of gutlYllll tiUl IIll dl-eli)ed 111() IlltlY d~o Ill nltlI1lld fOl III Iwl Illhlwl- and l~iJlmiddotb(lLiJlg plant TIllt l[Olllhup hns nlo b(l1l ntuptpl fot IIH lltlIll1illtltioll of lllhbpl ill 11lHhrublwl Pl(Jdlld~ HIIl 1111 hI ndaptld JoJ IIll ann lysis of ynt1J(gt( ic lllbbl[- The llllthmb HIP 1gtn(11 fill tIll fol1owill plimiph- III Grinding
tIll PIOPlly driPl t i~lIl 01 Ul tillg tIll pnHhHt to tll l((lllilllllh~lel of filWlH-- til plllllit qIHlIllilnth( lXIIHtioll 01 IIlbhlI 01 1(--IJl- () llsing oXWllutld olnuh (kttoJls IIt(talp and() fllltil for LIbbel and IH(ltIlIlyptIJllIllIoolYlnJld-o flJllh 101 niJlsl with t(lathelr high IlPililig points 111 to n C) l]olle or in mixt tIll thllt Pll mit tlll rnphllxututioll of luhll(l OJ [middot(ill ill ~() to (l mi1lutp It r(latiwly high 1lllIllllltlltP Ill to 1~11 ) l) lllllipitntillu till luhblI OL Imiddot(ill frolll aliquot () f till oltn ion I IlIlllI-i () f Hlltabhmiddot pl(~(i]litallt (willifhmiddotd lthmwl fOl IIlhlHI Hild llitlifild lllr fOJ JP-illl t~) IIlHkillphotollllliilPIIIIiIlof PlllPlltal of liht tLaIlS mittUl(P lIftlI IlIlbll (II Il in PIlipitalioll 11 II WI( Iplllh thnt (limiJlall till PIIOl dill 10 xtralllOlh (0101 (till dptl1minntinll Iph jill 011 tIll dtwlopllIlJIl of H HIli rOI1ll tlllbidity 111 hpl than I (olot rI
jJlIlpOP-ofallnlyi-I ( p(lllil1thb IIllijOI1ll turbidity or 1llt[lIinmiddotd d(ltl of jgtIp(ii(JlI l)~ lIltlkillU tIl plllltollllmiddottri( ntdillU al tandinu tiJlH~ (dlllilll wlli(h IhlllH(lill-- IP 1llutinmiddotly tnhll) t1ll1t an hlsl~1 oil the (oJlItlIlllItion of IIlhlHI Ill I(ill (lIPIipitat((L
TIll -I(p ill till jll()(Plhul HIP 1-- follOylt (1) 1l~UIIL uJ1lplls of thwl UJfJlllHl (II tliddl(l HUt dlipd 11Illtplial an lXIllltel with11 Ill of till nlnll ill t (oU tlllltIPlll[gtPImiddotatlup oil Iath at 11 Cbull fol 11 minutl I) iIP1lIin(middot(lohd til( (XUtllhllll Jltldl lip to It middotml ynlmlll til( (nlifild by (Illlifllgiuu HlId thlPl IlI nliql1ot of tIl (IalioPlllxUlltl nll Uillltlmiddotll(t to l-llll OIlIIlIllril fiuk- (1) For a trial Ilnditlg 0111 III tlll j liJmiddot~t IllHII IIjI to Ohlllll with lilt Pll shy(ilitnnl a 1(11 it 111 (Dod fill llli lIut ( ptotoJIIltlil IPtlllillg-- of pllllntnl or liuht tlUtllIlillal(I oil n (lpel OphotnJlllllI at rase hng-tlt (If 11 llJ Ill Ol It lollllil1lPtImiddott lloyidld with tIll P10]11 I 1110110shy
Ihlolllltt hmiddot Ii1llI Olllhi lIatioll for -1IpItillg UJlproXilll1l tply Wtl P ]Plwth )0 mp are HHlltk TIll Illldillg lliJtaillld fol tIlt 4-milutl tliall(~ll-
bull
bull
bull
RAPID PHOTO~IETRIC DETERIINATIOX OF R(BBER AXD RESINS 37
ing are referred to a table of equhmiddottllut~ previously p1(pa1elt1 on the
bull basis of 4-minute reac1inJ~ for tilE nmge of lot1telltlatiol1- of rubber or resins to bE elHOlll1t(led tmd gidn thtmiddot -tnnlillfr tillIP fill rUbbEt or resins aiter prE(ipitlltiol1 lwfolE photoIllNliI j(tltlill1 un IUade The r(middotnmining dllplllatt aliquot lll then HHllil up te ol1l1Jle and lpoundadillg ale marle ut the -tandillfr tiUlE iudklltll ill rhl tall1lmiddot for the final r(adillg~ -1) 111( milli1lnm or p(tCPlltllt- of lllhbpL (II 1(-in pr(s(nt are rpadholU a prlpan(l table of lquiltlput for tlll photoshymetric readings h1~l(l ill pnell e1-E on pxpPlilmlItal lhln 1111(1 u-ing as stimtlltlds pure luhbll in 1l1bbtl milllYb aIHI guaYllh ll-ill- lxIHlatt~ in resins detNIl1111lttion I
LlTERATlRE CLTED
(1) lUnSbull 1fl36 THE mURMIXTIOS IIF IOTA RE I III OOl THER llT~II
F1 bullrol IlY U(T1l0fll UfSlfi ~rrnrl r flm lt1 KEYS TI Bill Chern 114 44J-l59 illns
t1 ~ICPHHlObullbull T 1J3bull~ lUTHOO roa THE PtRInCAnu Or a(lIUl IRrIlHU It of TIn
PLRIHEU Htllllflt [ i Bill lallllall 111 Rmiddot 711middotj iIlus
I ) RHBERG P B Ul5 A METHIlO Or ~u(ronrll-nl Hi tIII rUIl[1 f71 ii illlI
bull 14 Hoss W flbull and HARDESTY J O
llH IR1ltDII Of HfITilIZfmiddotR DllIJS ltt 1 Yl fll Off gI bern JIIIlI i ~middotmiddotlf IIl
101 SPEltCE D nnd CuoWELr ~I L 1933 DETER~n-ATIOo OF RtBBER Ii nrllllpoundRBfR Iusr 1uI II1 amI
Em~ifl cttIliIa~~ r Ell i 71middot7i l11 (HI WALTER E D
1U44 ISO~nlS OF PRTlltSrr 1trHpoundV bull l UI n W lHHt (Tnmiddot 1ETS FROM GiYI l~iIl lItr Clttrn SII J UI titJ middotn9--C1 ilIu
17 J YOEbullbullr H lO~( roLORIlETRT 771 IPmiddot nl -W Yurk f H Plrwptric hmica
naly-II rimttry lUll XphHHlnmiddot~ y 1 1
11
HI) ~ fPHELolzTRf 57 111bull Lin xw Yk t H lt PhmeHt CblUlmiddot ila AnaiY~l~-(H lithrry and XIhmiddotILpfIY Y wirh enomiddot rrJlllrjr hy H KtlJnJU11 I
t~1I --- and ~ARVER L 1f41 nlua-w ~in L liLhr IS IP ll~ XIW Yrk
bull For-sale by th~ ~a~fr1nt~nf1ent Dt~c~~ogtnts-~ s t1i rArnn~ut Pn~~~ tJffieshy
Washington 5 D C bull Pl lU ~nts
bull
bull
bull
RAPID PHOfOMElRIC DJllImlMINAlION OF RUB BEn AND HESINS 13
RUBBER IN 25-MLVOLUME(MG) 2 3 4 5 6 7 8 9 10
r~
eo en ()
90
f--70z Q ~ 60ltl LIJ a ~ a LIJ 40 E 0
0 50
~ 0 ~ I 30 0 ~
A 20 I I
o 25 50 75 100 125 150 175 200 225 250 RU88ER(PERCENT)
RESINS IN 25-MLVOLLIME (MG) 2 3 4 5 6 7 8 9 10
1--90
80
en () 70
I z Q 60ltl LIJ a
50 0
a ~ LIJ 40 E 0 0 ~ I 30 0
B ~I20 o 25 50 75 100 125 150 175 200 225 250
RESINS (PERCENT)
lJIGunE u-Cnlibrutioll cUve for (il) rubhcr in 02 gill of gllnn11c tisme conshytainingl to 2G perc(lt of 11IUU(Il I1na (1]) rpSillS in 02 gill of glI1~l1ll~ tissue (ontnining l to 20 nelecnt oC l(sin8 (U(ndings Oil 1111 E(lI~1I llhotollectlit colorlmeter with 720-mtL filtcr and O-ntJ aperture the lO divisions llquired In uctnul prllctlce for pitotoulPtlie PllllillgS tlre omitted)
in vncuo arelntivply HllHlll qUllntity of (xutlnte is plllcel] in a lalge dish since the mass rOHmS nt the beginning of the drying process Pracshytically ull of the ne(tone is evnpollltpd olf oyer a steam Ol WItter bath and the residue is dli((l pnlYllized in It mortnr and preserved by
14 lECHNLCAL BULLErrN H20 U S DEPl OF AGRICULTURE
drying as indicated for fresh exudate In all ClSeS the products are stored in airtight containers in a dark coul place
The usualllnge of resins from gunyule tissue is about 2 to S percent on a dry-weight basis For work with this plaut therefore on1~ one curve is needed A typiCallesins ealibrntion CUlTe is shown in figure 5B
PnocEDuuE J~OH RUBBER ANALYSIS
Duplicate lXiLllCtiOllS arc made for each tissue analyzed and duplishycate photometric readings are made for each cxtmctioll the final value therefore reportcdreprescnt- nn avcragc based on the four phoshytometric readings
Thoroughly mixed O2-gm samples of the finely ground tissue are weighcd for analysis on the basis of l11oistUlc-frec tissllc The samples arc weighed to an accuracy of 02 mg Oil an analytical balance The method of deriying factors for making eOllections for moisture in samples has been thtailed on page
The weighed samples arc trallsien(c1 to the 2-m1 volumetlic flasks with the aid of l-inch glass funnels and 20 m1 of methyl isobutyl ketone is added to each flask The contents in the Hasks are heated m a constant-temperature oil bath at 115 0 C for 30 minutes uncleI a yentilated hood rhe flasks are removed and any adhering oil on the outside is wiped off with Kleenex 01 H similal cellulose tissue the C011shytents of the flasks am cooled to a standard tempellltule (25 0 in the writers laboratory) in a constant-tempelutllre ater bath provided with a motor stirrer if available and made up to volume with the solvent After the contents are mixed the flasks are allowed to stand for a few minutes until most of the insoluble residue settlcs to the botshytom The extracts are then carefully poured into JO-m1 heavy-duty centrifuge ulJls so as to include as little as possible of the settled insolushyble residue The centrifuge tubes are stoppered with cork stoppers and the liquid is clalifiecl by centrifuging for 10 minutes at 2000 revoshylutions pCI minute The clarified lIquid is poured into 25-m1 volushyl1Ietric flasks plOicled with ground stoppers It i impoJtant to pour off the clalificd (dlart in lWIt a lUlllie that the ill8ol11ble cNi(hwis not Sti1((Z1tp A 1-in(h funllel is plncCd in the neck of the volumetric flask A filter stick (fig 2 D) is inserted in the centrifuge tube through he liquid so that tlH enlnlged palt of the gtiek seals off the insoluble residue and a small portion of the exmet in the cone point 1Vith the index finger the stem of the filtel stick is thell held against the side of the tube towllnl the analyst who holds the tube with the thulllb rmtl t11illt1 fingCl The txtlHct is thell poured off easily into the yohunetlic flask without distnrbing the insoluble residne The COllshytents of the Hasks are then ))ollght to the standard tel11pelatme in the constant-tempentl111e wnter hath
The reagent blank us(d wit h the spectropllOtoll1lter 01 (olorimeter ig prepared as follogtvs ) 1111 of methyl isobutyl ketone 01 other solvent used is pipetted into It 25-m1 yolumetric fiask and 01 ml of protective colloid solution for rubber is added the mixtule is made IIp to olume with acidified Oil-pelcent ethnnol and mixed again the rcquired vo]shylime of the mixture is poured into a cuy(tte or an absorption test tube
From each plir of tissue extractions to 5-1lll aliquots 01 the clarishyfied extlact at the stnndanl tempCraLule ale pipcUed into 2ii-m1 volushy
bull
bull
bull
bull
bull
bull
RAPID P1IOTOMElRIC DETERMINATION Ol~ RUBBEH AND RESINS 15
metric flasks and 01 m1 of protective colloid solution for rubber is added to each One additional5-mL aliquot from each pair of extracshytions is similarly prepared to serve as a key to the standing times for the final readings as indicated in table 2 These additional aliquots are first made up to volume with the precipitant acidified Do-percent ethanol mixed by carefully inverting the flask three or four times] and allowed to stand for 4-minute periods before the reading is made on the colorimeter Vith these preliminary rendings a~ a basis the standing times for final readings are taken from table 2 For example if the colorimeter reading in rubber analysis at 4 minutes is 655 then the standing time is 15 minutes
The two rell1Lining duplicate aliquots for eath extraction are then made up to volume with acidified D5-percent ethanol mixed by careshyfuIly inverting the flask three or four times nnd allowed to stand for the required number of minutes as established by the preliminary 4-minute trial readings (table 2) before the final colorimeter readings are made on the contents of the flasks
TADLE 2-St(llllliIlU time for variolls (OllccntratioIlS Of rubbcr or rcsins aftcl iJleaipitation bcforc colorimetric readings mc macle
[5middotml aliquots of rubber in methyl isobutyl ketone or of rcsill~ in ncetonylncetonemiddotcellosol e 3middoti both made up to a 25middotml volume with pr~cipitantj readings on lvolyn photoGlectric colorimeter with i20middotml (690to iiOmiddotD11) filter and Umiddotml aperture]
RUDDER I
Range of colorimeter Approxima(e S~nuling i Rnnge of colorimeter Approximn(e Standingtrial readings after 4middot range in conmiddot tJIIIG for trini r(adings nfter 4 range in con tifillnlOalcor minute stunding time tcnt In tiSSU(l Unnl I t I t (rending IIlIDU C stum Illg lOW _ tent III Issue reading
Percent Villlits II Perfe~lt Jfinul 955-999 bullbullbull bullbullbullbull 09-01 00 01-03S bullbull ~ _bullbullbullbull_ Jl-O9 10 743-954 bullbullbull ~ bullbullbullbull __ _ 43-10 30 1420-550 bull ~ ~ 137-94 5 6_3_9-_74_2__bullbull_ bullbull bullbullbullbullbullbullbull_-_---- 6__8-_4_4---___ bull ~ ~ bullbull ____ MQrcthan 13ibullbull_-~_ _ ____ 15_~elow t~ 2
RESINS -----------------------------~--------
957-999bullbullbullbull ~ 139-01 60 11419-amp11bullbullbull _bullbullbullbullbull ~~ 13~5-939 10729-956bullbullbullbullbull_ Ii 25-1 middotJO 30 ~gtl2-40(L bullbullbullbullbullbullbullbullbullbullbullbullbull _ 2025-1320 5 595-728~~~ bullbullbullbull 8 as-G 20 20 IBelow 292 bullbullbullbullbullbullbullbull- More thun542-591 _bull ~ bullbullbull_bullbull_bullbullbull 038-039 15 2025 3
I Precipitated with O5middotplrccnt HSO in 05middotpercent ethanol When the npproxilllull concentrntion of rubber or rcsins in solution is not known trinl colorimeter rend
ings atmiddotJ minutes s(nnding till nrc mndelS n guide to the required finnl standing time indicated in the last column III prncticc UII cxtrn nliquot is prcpnred for precipitation and thIs is discarded after the trial reading is mnde
3 lrccipitnicd with OmiddotpcrccntlhSO ill HO
PnOCEDunE I-On UESIliS ANALYSIS
The procedure fol resins unulysis is the same as that indicitted for lubber analysis eomiddot(I]lt that f he -olyent js acetonylacetone-cellosolve ~)-7 tht precipitant js O5-perctnt H~SOI in H 2 0 and 01 1111 of the protective colloid solution for nsins is added to each 25-m1 flask conshytaining the aljquot of the extract before the precipitant is added
PnOlmmlHlC INSlHu~mNTs UECoIUlENDED AND CALCl]IAlION
OF UESurlS
Photometric readings of percentage of light transmittance (T) ale made on the Coltnum double monochromator spectrophotometer at
16 lECHNICAL BULLElIN 920) U S DEPT OF AGHICULlUHE
750-111 wave length or renclings n1( mnde on a colorimeter pLoic1eri with the monochromatic filter eOIl)Il1l1tioJl for sllecting the npploxishymate wfLYe ]cngth at 750 1Il~ For routine deterlllinations the Evelyn photoelectric colorinwt(r ployided with aTW-lllJ filteL is IC(0l1111HIHtll
The liquid in hich the preeipitnted lubber uld rcins are susshypended is pOll(d very cHrdully down the ill~idl of th( clette o absorption tube to lLYoilllllC fOLll1ntioll of ail bllbblls Aft( LUbbet find resins preeipitation wlwn the EnLynpho(otkcllie (olo1imetll is used the readings are nmde nft(L thl standing tillll- hOWll in table~ It has been foulld (OIlllliellt to 11lPtipilatl tublwr 01 llsiIlS from the aliquo(s at ~-millute illtlLvals This allows stlilieipnt tillle to check the eOlolimet(r and to makc 111( lNHlings Vlwll a ehangp is IlltHk fLom onc rending 10 the l1lxt it is advisablp 10 llle the clIvctte 01 absorption tube nt lpast twkp with slllall p(Iltion- of the llllltiol to be leitd
After the colorimd(L lluding lta e becll Iltndp till IlIl II igllIlllS of lubbel or resins or thc lpL(el1hlges pnslnt in Ihe aliqllot are r(u1 from cal ibmti(Hl (urVlS (fig~ 4 and raquo or from plepn Led tables of eqllivallBts baecl ill each (liSP on (x[lerimPlltnl data The results are expressed as percentages of dry weight (S hours drying nt 100deg 0) of the original tissue The errol lltle to lCflyjng the insoluble residtH in tbe voltlllletLie pxtLHclioll flflsk wlwn the pxtrnetis being mnde up to YOlllmC is V(ly slight sinlte only (U gm of tissue is used FOLroutine allalyscs lhis ery slight eLlor mny be dislpgnltec1
EXPERIMENTAL RESULTS
The experilllCnlal reslllts Oil hi(lthp method- of tU)lPI and l(sins analysis a le based ttl( d icussld blicfly hlrehl
PHEPMINrlON OF SAlULES
No difliclllty was expPtitI1(ed in pltparing slmplls of llllrscly-glOrt guayule plants 1pss thnn ~ YPH1S old 101 rllbbpl alld IPSills analysis In the cnl of Odll filld-gl()n gllayull plants PIIOtS hopel mtty be introdmp(l by the custOlllalY Jlwrhod 01 pICpalillg Ihp sampl(s 101
HlutlYHis as is lwipfly i n( ita ttd ill th is s((tion Smh enOlS do llot nffCct the ])lCcisioll O[ t1H llwt hotls for LllbbtL n nd Il~in~ nnn I sis i nee till) are due solely to tIl( tbsup--ampling (llo(pdule in thi (a~e of oldeL field-grown plall TIll 1lllt1lOcl of salllplill7 fipld-gl()l1 plants JllOLC than ~ Y(HrS old thenfort Ieqlliles iurtlHl jnttigntioll
lgtAHnOILr~G FOR HEllOVAL OF UUVLgtS
Parboiling which (onisls in boiling gllltyule plants in water [OJ
8 to 1~ ~ninll(s ~s col1llllonl) uSNl a~ n llHans of Itlli rCnl()y~l prior to drymg nnd gllnllng It I~ tHI([())P ll(e~Sllr to ltItLeLnunc all possiblt~ eflct oi tlti PLOtPlllll( )ll (Il( final results Exp(liments have sh(nm that (helt i- fl Flight loss ill til tmiddotjght of lOO(S and 4(ll1S In I typi(ul lXpelillltll hlu1llHs of ~- ii) -1-ytII-old gllllll( pllllb were Italnd at randolll Olll ( of talns wa- paLllOil((1 and the le~es (1( haIHI-pi(kpd [lom till o( hpJ Ht Both pis (1( dlipd for 48 hOttlS at (i) C in a llI((lwlli(al (011((( ion Oyell Th( lpsult are SUI11111I11izNI itS follows
bull
bull
bull
bull
bull
bull
RAPID PHOTOMETRIC DETERMI~ATIO~ OF IfCBBER A~D HESI~S 17
Dry ucilht lust ill lariOilillf
Plaut (pcrcrllO 1 1 -I2 ___________________ _
213 _____bull _____ bull __ _______ ___ ____________ 12 2(
pound(111_ ______________ 1 R
4_______________ _______________ __ _____
A __ bull __ -_
The efred of parboiling on till final lllalp i SUllllllatmiddoti7(middotd ill figmc G Rubb(1 lecoYelY w(t about 1 percent higher for parigtoillltl plants and lEsills re(ovelY somewhat o-er 1 i)(lr(lllt 10Wlr The (Ii tference in lublH-l r((o-elY cannot be ae(01111tltlt1 fot by loss in dry weight _ due is to be found in a study of thE grinding lwhadol of a parboiled and an unpnrboilEcl shrub The grinding of the patboiled shlub in the hnml111 mill is much fadlitated and ns a rule for tissue with a rubber contCnt below 10 peteent llO aggregates of rubber deelop in the 1Il11ehinr during the (Jpelatioll Yitll the unpnrboilNl shrub some dillictdty may 1)( (lxppliellrl(l Sill(( sOllle of till sti(ky ltxlldutl Oil the plant may scI( u nlldei for the fmllHltioll of lublH1 ngglPgates Til is apparently explnins the npparlllt los in ruhbpl frol1l the llnpariJoiled hrllb as eompnlelt1 with thl palboilld (fig (i) TI1(loss in r(sins
II
RUBBER
10 f-
Ishyz LIJ 0 0 LIJ 0
9 --RUBBER -shy-------shy
-- RES INS -shy---shy-----_
IJ) 8 I--Z IJ)
LIJ 0
0 7 f- RES I NS -0 -shy0 LIJ III III J 6 f shy0
LEAVES REMOVED BY PAFltBOILING
5 f shy -shy - BY HAND PICKING
4 I I I 35 30 25 20
SCREENS (SIZE OF OPENINGS IN MM)
FIGlRE Ii EtIe(t IIf pnlticlp sizE Oil lEcorPQ- of rubber lind (iiil1s when lEgttiye wEre remond hr Pl1liloiling lind h~ hand pi(king ((Dlltrol) plllllt1lt groUlld in t hammer mill
6114038-46-3
18 TECHNICAL BULLETIN 920 U S DEPT OF AGRICULTURE
recowry from pUboil(d shrub may be due to the loss of the resinous exnc1ate during parboiling This exudate forms ns It SClim on top of tlw )iquol in the tank
On the basis of t1wse results the recommendation is made not to yaly the nwthoC of leaf lemoYal in any 011( lNi(lu(h project Then fltirly compalabh IcmLts should he obUiined
70 ~------------------------------------------~ LEAVES REMOVED
BY PAR80lLING ____ BY HAND PICKING
60
-I-Z 1amp1 0 50 a 1amp1 a
en 1amp1 gt1amp1
40en gt-CD Q 1amp1 Z
I shy 1amp1 30 a l shyx C)
1amp1 ~ J 20 I shy 0 I shy
10
O+--L__L-~__L-~~--~~~~~ o 10 20 40 60 80 100
NATIONAL BUREAU OF STANDARDS SIEVES (MESH)
FlGntE T-lJiMlil)utiun of l1Ultkh si~(s of gnll~II( tiSSU( JrIOllll(l in a Ball amp 1ew(1 mill to pass six dllIerNlt S(I(euroII 1(IlYes Iemoved from plants by palmiddot boiling 11(1 hand picking ((olltloll dpfo1iatld plants dried to 1I lUoistufl l0I1t~nt (If 01 to o) 1)(ICl1It ground tiSSlli IbalH1 1() minutes ill II ~i$hel
bull
bull
bull Kahn shuk(f
RAPID PROTOMETRIC DETER~UXATIOX OF RrBBER AXD RESIX-i 19
GHl~DIgtiG
bull Th~ entire pant 01 plant l)iHt a~(gt fl r(ll it pllllIIirU1ry lSillg fur J hours ntGi~ C prIOr tD t 1( plChmll1atmiddot rLlmhll III a II lItmiddot or n Ball amp Jewell mill ~n llltllysis of paldch lzP- nftl~l (oar-( IIindill shows that tlwy ar( about tIlt llllH fOl parbojlP(t awl IJllllluhoileu hrubs I fir 7)
The coalilly gloUllll ample i-- thPll Ildlll forI toUtmiddot at ni C afnr which it ha lllilobtllL(gt output of ~ llllut lII hmiddot- dptPlIIlilwltl by drying submlllpil- at 1110 fot hOtll- TIll 1 IIIIll i lltllt lmiddot0l111d hi a IluninHl mill TIll mo(lel uP(t in thi IIIk i 1I Hu IIIOilll mill as IllUllifill bv Hoss nnt Hartlet ( 1 -[1lt111- with n1ll1l1 pldushyrations ittI lilnbhell b rill HanlIolll V0ll11nHiol1 ElIillllmiddotrill (0 The size lutllihl11 iUlJnole So I ( 111m t ~ II t HUIII Xl) ~ I L~ 111m nnd So 4 lillllU1 11 ttllilhmiddotj 0 r tllP Imiddotlult~ p(lln-It willI t11(e Sll((IIiZtS with )arl)Oiltll awl uil)Jtllboiltd hrlll b lOwl1 in fif1l1fmiddot-- This hows t tnt 1middottttIl ~(I 1 llllll (Up jlllilnl IHlt that
r------~-------r--- ~ --r IHAMMER-MILL SCREEN
O~ NO1
NO2 ---shy U NO 3 ---II
I
bull lL
z
r ------ l 30 ~ gt III
i I Imiddot
i ~ I
I 1 I I
~ 20 I - 1 iii 1[ r 10 ~ ~ ~ I _ ~ I r A bullbull
o bull L-~__~__~~__- ~~ 20 40 60 80 100 40 60 80 100 200
NATIONAL BUREAU OF STANDARDS SIEVES (MESH 1
Yutln I i-tlillltiuli Hf pur id lZt f ~naY1l1 t middotnt r1 lI1 i ~ a hatlltlllI 1IIi11 to 1111 Lx IHtllllH middotIn Lt-anmiddot tIlllunl loy la1 litkh~ omrl t 1) tHul parbuih~ -t B ~ thmiddotfuliufptl ]~lahr thpt tu tt fit t 1 It+gtr-tt1 Jnui~tHn eunttlIt _~rnlitl tl~UP ltakmiddot~~ 10 UddU it~ 1 rtmiddot4~pt~middotK1~r ttakt-middot
bull So 1 gingt- 11 tt-liuin-Iy ltr~pl [lPlItl1tat of iilll 11animiddotImiddot- Eqltrimiddot tIlllll hnnmiddot llOWIl dutr fll llltldllllUU xtlutioH 11pound lnhbll lIl lP-ill frolll IolUlIl ~tlaYlllt tl-IlP by dlt IJwtmiddotlUlmiddot lItlilwd oil Ill 14 - 01
i-mllt 11111- -lwltld hi INd I li~ Ii I TIll lllhtIlttj of Itiu~ So 1 (lltll j thnt 11middotmiddot01middot lttwmiddot to amplil tltt Iollllli tilt art lpdnn ib
IntIIll ll~ i po--ihJI with tI lLllit Ilfltl[lll1t It honld l Plllplw izmiddotl rImt ilt tht h of -allllhmiddot with l lllblPl
~ontlnt of ill PPltllt til lIilll it i tlllt pll--ihl 10 11-middot t(1i Xli L
20 TECHNICAL BULLETIN 920 U S DEPT OF AGRICULlURE
Even with screcn No 2 difficult due to rnbbel tlcrltreCtlltiollS may be ob tl
encountered In thes~ caHeH it iH lWit to parboil the shlub fOL leaf lemonll and finally to dry to about 1 to ~ P(l((llt of tnoiibl1(l pound01 b(~t results jn ~rindillp in tlH hanmHl mill
It iH aclvlsable to provic1l thc hammer mill with a ground wire Hillel the presence of static electric (harges 011 tll(middot partkhH will ealls( Home of these to atlhelc to the inside of tllP (olltailWr OJ lila eallsc OI1l( of till pULticl( to form ngg1(llatls EIIolin lalllpling fl01l1 fhis SOI1I(I mlly be (onsi(h1llbl(middot
A1I10l1g the Holnllts with high boiling point that lIlay Ill IlHld in rubber anal)Hs I1IP Illllhyl n-alllyl ketolle methyl ioblltvl kptOIH diisobutyl (tOIH blltyl tHptate llethyl amyl 1Ittail (middotthyl(middotlllmiddot gly(ol diethvl (middotther and n-bntyl (middotthel (labl( 1) TIHse al( also I(sin 01shy
middotent but th( 1(~illS n1( held ill olution by the rll1)bpl pl(l(ipitant tthanol wll(1 lllbb(r is 1)J(lipitatNI (S(ll tabl(s alldmiddotl) On tIle basishyof the lxpHilllPlltH tll( btsf nil-round lolPlli -rol lS in 111( PIlHPllt method is lt1iisobutyl kPtonc wld(h was not IIltlllllfaltllllmiddotd ltIlling Vodd Yflr n A suitable Sl1lgtstit ute iH llHthyl jolllltyL htolt whi(h is l(porhd as llolltoxit UJ)
Clllos()IY(~ (ethykn( glYlol monopthyl (tIH1) blltyl earlgtitol (di(thyl(ll( gly(ol llIollobutyl (ti1(r)~ and acttonylacetOll( may be used as resins sohrCllts (table ] )
In the earlipr work with (sills analysis cpllosoly( alolle was selcmiddotet(d as a suitable solycnt Aitholllh (ell()~oh( alone is pxc(lllnt its rplllshytiwly gwatlL iscosity 1(I(b to bubbl( formation nft(I (SillS pr((ipi tatioll Thi- increased thp (xperimentnl (LTOI OIl of tltp othll I(sins solpnts tI((tollyla((tolH has the proppry of glpatly lNlulingshydH(OSity 11(11 altld(( 10 othr liquids This sohpnt tlHIeforl wa addp( to ((Uosoh( in slIflici(lJlt tlllIonnl to OPI(0111e the dinieulty On the basis (li~ex)le1inwllts ~ purts oi~ a(donyla((tOlll to I puts of (elloshysoh-f (bolll by olume) as Splldcmiddot(l Thp 01 hel Hoh(nl listed hutyl clLlbitol at l(llst the t((hnieal-g1lld( ploduct uSNl is appal(ntly not as good as eithe of t1w ot1(r two () a (ombinatioll of tlWSt
The SOlVllIts JOI liSt in tumlyzing artifkial lubbel$ hy tlw pr(senf method appllLently (lcllIHl on th(middot kind of llI))(I lIp-ityl (Jxidt is suitable Ol BUlla fi and hutyllthlI for butyllllbbl Tlwse reagents IlLe technical g1lld( Calboll amp CtllUil1t Ch(lllilai (OIP This Hllbjp(( hilS not bepn (XtpllHl(ly illwtigated by till WIit(I
PIIECIIIIJ-
All tlst fOl Ih( adlqlJalY or till IHllipitullb ll(Ollllllentillllll11Sl bl baset] on the plctisioll of tllP final I(snlts oiJtairwd with the methods The )redpittlllts s(1e((( n HpJ (xtcllsi( (xp(IimPlltatioll all HatiH~ factor (Hee fig Hi 111lt1 tabItmiddot (jH) Ext(IIin tllts llllTild Ollt hanmiddot shown that H Hatil-gtflltlOIy [gtIpeipitallt 101 1lIbblI is (li-p(IT(middotnt HzHO (c p reagent nil POll sp gl U-lmiddotJ) ill li-P(l(Put (tinmol by vohmlP liol (tllayul( Ipl-gtinl 1l)-P~ITImiddotllt H)~o ill Hl) by ollln( ii lL satishyfaeto7-y l)lp(ipitunt A solution of 1 palt of H~~o to 1 part of H~() (1-1) iI2So1 nnd abo yarious int(lIlIPdiat( proportions of tlllse suhshystanCPs giyp fait 1(511It8 but with till inlIptl(l ill [h(gt ratio of H~S01
~
bull
bull
bull
bull
bull
RAPID PHOTQlIEfRIC DETEMIlXATIOX OF HtBJER AXD RESIXS 21
to H 20 the )olutioll becollles somewhat vbcou5 and precautioll Il1Ult be taken to ttvoid bubble formation When it i5 poured into tilt Cllvettes
It should be lloted that both of these precipitants have an ftellleshymmiddottion It was found that when XHjOH was used in the rubber preshycipitant in pInt of H~~O~ the readings were -table l)Ut were not reshyproJutihk The lIl of XuOH in pInel of H 2SO j ran nHittble result as a llth H(HY(Pl WIWll til( li-P(l put lthatgtl in lublltl llnalysis or H~O illlP-ius anal)j wn-i uddint(1 thl eharalteliti(s of till liquid with pleeipitated ruhber or resiu in HI~P(ll-ioll n ren1 on the lpNmiddottroshyphotometel m tololinlPtprfollop(1 it lPgnlal lIlll II~ lxplaiHd on pHgP-I (Sl( figs 11 aIlIIl) Tid made it lloible to outain lEPJOshydlHibll tpnlt nntI (onplt1J1(Jttly till JpqnitPIl tlPgJPP of PJPcljoll
IIWIE(TI 1lt COl~101J)
Jtl thp ItJiPl middotxlwlillltnb hefoJ thtmiddot -1l]YIlIt allll pnmiddotdpitallb had lIptll ptoppJly adjutp(l it l fOllll tIuH till llP or a Ploltiw colloid -wll ltIi1)cJ [ttlJmiddotntl- imlIopl tll lmiddotpro]lIibility of the lPlllt JmUkllly ()Ilt 111 U lput lUlU illlihumiddot tOJllPOlUtl tpHd liglyeol teltlut( - llpanlItly IllmiddotlfP(] to lit til I1m t IHflll lImnnmiddott nftlr tlH filial prOIptlllll WtlP dlvPllill1 tlll 11lIlpfit (If thtmiddot [llltlltin lollohl wa Hot 0 natlv I1l(lhmiddotd III rlumiddot Ia- of tmiddot ill tllmiddottJmillaritlu it b [1 hmiddotjlmiddot til IIpoundgt Ir llH1 It liltr ill-llImiddottiT Ina lll ptlPII by it U( in ruhhfl mmly j 11If dtmiddottail fOJ tltt lllllmtlllll If thl plot pet in nlloid ~llntill tltlmiddotlImiddotmiddotlttlatiflll lIOlllllllhtiPI1 are iPllllll page
liTFHFEHliG COIOf
(hi II tht lllail 11111111111 that had til ill -111111 II urklll) om tlH method fot lublJtt tlIlO1 rpir- nlalv~i in plaut llllpll- wa ttl (lilll~ inare tIte (gt1[01 till to tIll ptP-PlHt f xi [aIWIIII- 111 TIlt amount of (olor varip from lUllIt tn -amp ]pplwHlI nlt rhmiddot lt IIf thE Hl(ltllial tllP part of till plllIt -lI11lhmiddot(l tilt hi-tlllY f tlll plaut mtteshyrial ~ub-lltInent to Itlllmiddotnmiddot-rill lliI 1011middotly OrllPI Inlw
In ruhlwr lrtl-i I Iii 1101 au Itmiddot 1Iplll11l by 111[ I--r ratmiddottilt thE -lllll]t with uptoIw or 1middotmiddotlIll-ol - wIdell [llllol- rlll loillriu nutttel autI thtmiddot lpill- Thi- howmiddotvt n(tnll- til lXtla -11gt1 ilt prlJ~edun) In lP-ill ltluay-i nllHufldy tlW[t j 11 1 1IO(PIlln fill the 11shylImya of hlulophyll Hwl rIlI-r middotIOII IHlttlmiddotJ dlH lUtl~ In plltIH withoUt alo aiftIriL till nmiddot ulttrll
111 pllIbIll1l Wi tilmiddotr hId h It-ImiddottHI tht Pltlpll 1 hlitlt lilt tlw tulllWlli tollImiddot uIwltllIIntut -lltUIhorlllllltll 1111 tIll tlettlllliIttwr IIf t 111 lWlrl-Uamiddot of bdt tl11blLlittUhmiddot r [1 tItmiddot preshyj
lipitatifll 1lJ llllllWI atbull 1iI- in III -1nrmiddottIi fHlttalldh nlrillU~ amount rf middotlorilig lIUlttll Iii lhll of ih lltmiddottllllhottohttt~l l~ol()r infrtl Hm II upd 1 rwmiddot tld~middottilmiddottll PlllItlhi~ f it j proYitiltl with tIll lilP--UlY tU(jlIdlllIlml tIltmiddotmiddot lllklllUIlI
EIECTIol OF 1 [EGTH~
-Ptfmiddott ral tracilull ru~lI gtIll fr 1 nllb t ~xtltd 1 lIlt-th vI iobmy1 ketommiddot lWtl rill [ Ixt lttltt ll UttollylaIiIitt1l11I1t~ ~-I itoiu YtHil)u~ typp of ~IHaylllt f i lItmiddot art hraquoil ill fio1ll1 ~l Th~ lp-nlt fill I11oohl uio[1t ttl willlr til tltN- fur rht IUiXtIUt iwliutll
100
22 TECHNICAL BULLErIN 920 U S DEP1
90 bull eo
I shyz 70LLI 0 a LLI a 60
LLI 0 50 z
a ENTIRE 2-MONTH-OLD PLANTS~ 40 b ROOTS AND BRANCHES OF ~ 3-TO 4-YEAR-OLD PLANTSen z WITH LEAVES REMOVED ex 30 a C CURRENT-SEASON GROWTH OF l- )-TO 4-YEAR-OLD PLANTS
20 WITH LEAVES REMOVED
d LEAVES FROM 3-TO 4-VEAR-OLD PLANTS
10 A
0
a Cd 100
b bull
10
80
I-Z 70LLI 0 a LLI 60a
LLI 0 50 z ex I shy 40 ~ en z ltI 30 a I shy
20
10 B
o~__~__~__~~--~--~--~--~----~--~--~ bull350 400 450 500 550 600 650 700 750 BOO 850
WAVE LENGTH lM~)
FJGcm O-Sll((middotlllll tramaniW1IHl (mrpS f(JI (xlmll 11011 n J1ll of jlta)nle tissur ill n 2--m1 Y011111P of (A) Illrthyl ji1I1J1ltsl krtonp 1111(1 (ll) nt(middottQnyla(umiddot tClIc-C(l1osuln a-i
bull
bull
bull
RAPID PHOTOlIElRIC DETEH-UXATroX OF ntBHEIl AXD HEstxs 23
ThE dula Pl(S(l1t(lltl indi(ntp Ihut 101 Illp ulimls llHthyl liohutyl htOlIl (lxtrHts (lI(I r(dolls of Il1Hxi11111III nigtol]gttioll wiH1I all (is-lIb 11 cOllsic1(]((l n1( blhn(11 wn ( ItIl( Its lIO to () I1It~ nlid Ii to Iii mJL
WhllNIS tlw I(gions of 1middottnL(s( light 1lnlllittamp al(l lgtPlW(PIl wan Ipllgtltsnr) to Ii nllt jW) 1I1JL nlld alio Silllill1l 111l1b (n SI(lIlId 101 nc(ton ]altmiddot(fmiddotollp-(llloolp ~ pxt Ill of 11a 1111 t illl TIl( (1101 du( to lolo ill tlw litlltitl a 1Il1 lullll(I tH lPill- hanmiddot bpllI PI(_ ipitated ma he 1((I1((d to fltI ynbhing poillt II ph( illg OJ illshylmiddotJall(( WIWp balld nhm ()) IIIJ1bullbull[1I111 lxjlPIitllll1b Illln -h()1 that Ih( lIIot uilahl( WHYI lHlIJ fOI 1-1 ill 1l11J1l(I HIH11Pill- illllllrsi i-in till IlPighl)()lllll()(l of ~llIl1lt bull
bull UIlIilHlIy of n typhn] lXPllillllllt to )10 l1iP(tiP ((JIlllo( of (ItOIS dul to lOIOl in 1llblnI Hnd Iill xtnumiddott 11(11 IIIIolp t jUl i p1llelll((l ill tub]lL Till llhlllt- 1tpIO]II Hnd ((llll~()h whit-h UI(I ](]Hllilltl n 1I01lllIhb1 01(111 lxt 11111 IIll 1llll)1 nmtp[in I and )(middotills Tid IIlnkl it poiblp nftlI tlIp uplll1tillll or tlll o1PIl( (0 [niH lip 1Iidl1p~ of lI111 11111(( ill lit ll11l1)[1 (llnlIb nlld Ihll
Sl(ll n ol1lliOI with tllP olnl IJllt illiollt HIl Iltlllll llllI (Ill ltllthpl prpipitnnt j Ihll1 nddld OUI ha a lIilPt lP( of till lIiciPlw of WH( lllIgth 7) lUI- ill llilllillatiu (nnl till tll Ixtll1I101l ()lll~
Tuu tmiddot-Elilll IJl flrldillY 11-1111 lrlllI IjfJI til islII 1 1(1 ([rllt IIIIIJIlIr JiIlIt~ if 1Il( Ihll 111111 k til I III Ilrln I 1Intd tf 11111 JiSf fill I I II I tIII Ilf Iilltl 1f1JlIIillII1f I Till 1[ 1 IId 1 (I (middotIt 11111 (I1I1iI1 1lf1IWtlfJlIIllfflr p middottrllhIJ11 II J III 7IImiddotIa 111 111 lilt jJIp 111 wilTII
t~t tnVIli~ ~nn r kn t~ i tmiddot ~~l Jr 1middotmt ltlTt
HmiddotOtt ~I~ lin t I ~ 1 t~~l ~qrmiddotthtmiddotrtwb
Hult-middottltlru t T Hw ullut rHtt~ r II I ~ PH~lllt
A~tmiddottHHjmiddott~rjd rl ~gtllh 1 tn~th~ ~ ~ middotI lt~ b w bull hmiddotth~ 1i~lIhun 1 Ii tnl Illd1 -11lt1(11i lullI lUI tJl ll~ t1~11n( I Ihan1li flfttIJir Ult I Uuhtltt ahuul l(hmiddottHmiddot~t trv r fti HIt lftbyl tlonhUt)1 k_hIl( 2 m~ fmiddotf tuhlHmiddotr In mlth~ llmiddotlf- 1 t r
t r_~ t j
Arhlitlltd ~llIIDHl NcWitn1 ( Ar-(lt()nc~middotttrrtrt ritJJI~ -Iu nllJtl4-middotr
ACtmiddottflnp fmiddotxtrn( ~ T-P511ftf tn mtmiddotth~ 1 ~difmiddotut~ kdn 2 nltt ulruhhtr in Un-tIl lltbu )J~IYt
rUth(Hl~hltlft HhubU
Illlh(I(t tttUtUt hUbtl til J ~jlitl(J Hilllll trtIIImiddotjtl1ll
(UShl I ~tlO wHllolH rulh r (middot1111$0]( J~rru t t )lthyl 15bullbull1middot1101 klll1l
Ili( UHUicbcul ~((i1rUtl ~ulu1iin 1middot lIUIll Ilti lrllltlllt I Ruhhr llt1thuI r1 -1 Irld
ltlt1111Sh 2 nuz f)rruhl~rm nlith~l tu- h f nt nil~middothgt(H] tlrlftmiddot 9lUtirtl middot1 1
rlcltfl( H(l dnllltml it
(IISllhH~rI( Iultruhtr CII05 1v ltTlft I 2 UI~r ublwr In llldh I hlt~1 11) lgtjdvr(llsl~9rlltmiddot middotlmin ~ I~ gt AIHItilltl no IrttipHallr iI
~ Bbnk 10ol m(thyl i~tmiddotut~i kdHn H 1 m1 j~~ l1rH-t lt~tlfltmiddotn sf n it ll HltlMjftr~nol O2~mlJ ~U~1o-ulp ti~tW -xtra~middotl(lt1 ltt 411 ml bull ie f Ct- kft rt t~ tirattJ middott ill r u l1kn ttJt
in metltl isobutyl kNqnf nn~i mljp ur tmiddotmiddot ~oml ~urr tttl i t w ltJj1JH kt 4t 3 nlank 1 mL((l1t~rthmiddot(middot mI mttr~ ~but a kmiddot tmiddotc d 11 ~ gtli~b~ hifIAft- fl~ lL lnti 149
ml8(dlfilll BO bull 02 gm guayule U$Stl(middot xUlClt-l tf(h tft wI n nmiddotmiddotmiddotlgt 1 lznt on tmiddot ~Jt r~1 ~~u~~ H~ iI~ thT
24 l$CHNlQAL BULLETlN l20l S DJltJPT OF AGHl(CLlOHJltJ
In table a is pl(sentc(l such c1il((t edlt1tIHC showing that thc (0101 Ixtrnetccl from guaYIIle tisslIe wit h II(P(OIl( n nd (pl1oso[yc is cll(div(ly sCIe(nec1 out by the s(lp(tion or wnw length )0 miL Oil t1w SI)((IOshyphotonwtpl This tnb]p all-HI ihos thai thl Juhlwl altl(l((1 (nn IJl quall shytitntivcly 1(I(()(Ipltl in tIlt PI(ilIH( or Ih (o]OIplnwPIials and Illsins and tlmt Iuhb(l WtlS nppnlllltly 1I0t (xtltI(((1 110111 11l glll1I1l lisslIt b~ tlHSP SOhlllts Thls( ((suIts ginmiddot (OliIHillg (idJt(( that t Iw IISI of waYl llngth i)ll 1Il) OIl till SppdTophot OIllltPI ii t hl 1101(1 p(oshy(ellule in photolllliTie IlIlalysis of luhhlI OJ l(sin-
SELEGTIO- OF )IOiOCUHO)IAIIC ItIIm ((1111110
On th( basis of th( IPHIlb shoWIl in tabl(l 1 al hlllpls (1( IIln(lp to SPCtl lC the PIO]Wl 11101lO(lIOl1ln til Ii ltlJ ((lIllIJi nIl ions 10 llIiOlS (oIOlimet(Is 111(gt 7W-Ill~ filtpl flllnhwd 101 til( I1~lI1l photoshyplpct1i( (o]oriJl1ltll fol which Ill( (hlll(IlIiitit~ oj t hl Ilda he light ilUIlBlIIhiSioll (t) elll nn -hO11 ill fig1lle 10 iws satlsfa(lolY IPshysultl 111( iiO-mL HitlI olllhintioll 101 whkh ttp (middotIatinmiddot light tlnnsmission (ullmiddotis a 1-0 showlI ill figllll (I is -nthdnlto1 hut this is not stnlHlnld NtllipmPlli
Up to fhl PlPHllt lIS(middotflll pound11((1 (ulllbinntions jn lltl iOO-I11L Iunge hayc nol bllll SlClIlld 101 lhp Klpt 1-1I1l1I11PISOIl (olOlinwtll bu fnltlwl nttCl1lpti 1( )(illg IlIHd
TJIpound OF ST~lmW AFTEH HIIJ1EII Oil HHSIS rlll~CIIITTI(J
~ considl1ltiol1 of ttp lillll of Inlllling af((1 plpeipital ion of 111gt)(1
01 l(sinSTlOIll ollltionis impoltant J(jl~ thC1HI(Plltngp of light IInIlSshy
11 rshy10 f shy
09 f shy ~750 Mil- DOMINANTI
~ 08 cshy I WAVE LENGTH z
I III III i O7 - I III
~06 - 05 shyw
a
Igti= 04 - 720 Mp DOMINANT ct WAVE LENGTH- ~ 03shy
02 f shy
01 t shy 1)O~~~gt~- J 600 700 800 900
WAVE LENGTH (Mp
bull
bull
bullFIGlRt IO- COJllPIUlItiw ~IW(middottltll tlnIlRlllii-lion (II (IllP( 101 1i11(1 olllhinulloll
with dominllnl Il(lllllgths at 720 and 7iO lUi
bull
bull
bull
HAPlD PHQTQlfE1IUC JjETER~lINATION OF Rnmrm AND HEtiINi 25
mitted (spertrophotoll1eleL lCuding-) Ol light (1 (tClcrl (phOlOshyJluol01l1et(L lcndillg~) i~ StlhjNl to (hangl
]fjt~l1le 11 and l~ show that ill til( (asc ot tJaugtIllitteltllight llJHC th~ (x[llliHlllIlnl (oIHlitiOllS tllpl j lilst n dtlln-e ill Pll~(lltngl or UllllslllittnlH( follrnY(l by It ptJiml of lClntin stability with only sliuht (1111 tHn- a f(Pl a lIt1ll1btJ of minutes The light t UIllllitblllll t l(1 ill(Iln~(s This lIIay IJP llllllJltlli7P(ll1 ffl II ow 1Ilt )( f(( darI oliIII tIIlIlNlIlitt(IIIlfJIIlh (iditilIiid Ilil1 pllIipintnl )uoshyIn Of ( 8inx in (~f1( I~iUII i~ Ild stahl I 11 itlll If 1inl nh prlshyilli(ioll of 11l1d(1 II IJIX f) jllIli II (fJJltfiIIlilty slllMI IIriot 1) IIIPldUnl1i tll(I1I rllltltilJl oj tJi~ Jlt jiot IUN ilUf Jxl1 will tIt( tOWI IItlllilil I 1llIlllblJIol I ill I~11l11111 d ill till ifjuids JjOI scnttplltl light 011 till phololltHJIOIl1lttl till dilPCt ion 01 elangl b tlw IPrfIi (If that illrli(atPll rOl tlulll1Jittp(lliuht It Itlll b( llluliJr I-(Pll that if l(middotndlnJ- IIIP mad n itl I t lIP ~()ll1d()lb lpalll this pllioJ of nmiddotlatirp tuigtility tllP llLot tIOllt thi Olll(P (nil bl IPdUCld to tIl lltini III 11 Ill TIll l~adiltg (illH~ bbll Oil tlHl datn rUl lublwls and llsinlt Illl ginll ill tnhh
50 r----------------------------------------------- f shyZ
~ 40 ~----~W~A~V~E~LE~N~G~T~H~7~5~0~M~P~~~~ ~ --------------------=-=-= ~ 30 f- WAVE LENGTH 540 M~ _z _____ ___ -=- __ _ ~ ------shyt ~_=---=-=--I GUAYULEIII 20 -Z HEVEA ltt II KOK-SAGHYZ f shy
4 6 8 10 12 14 (6 18 20 22 24 26 28 30 STANDING TIME (MINUTES)
FIlirtn 11 Emmiddot of wav hll~rh Il li~ltr tlall~lIIit1alHl aftI IUIlItHt -Imlli lug 111m for guaynh llmiddotn 011111 middotiolIlJh~z 1111111 llijlitul1 flolll 1lHlh~ll1Jllryl k11II11l ~(lilltlll h~ lwitlitll 111Inu1 111l~1It1 2)1111 o1U11111 (Helillins on (illllun tlunhll IlIIJlllw]ntllW111 lutl(I[lholtllllltlt with ijUjt Wlnl IHI Ilf1 I
11 EFFEGT OF Hbli 1 -()JXT10~
Tilt lnblwl ~()h(llh pxtnl( till IPillgt ubo It 1m nllu1- bellt -~atea thut ~lll 11-111- tUP olnbhmiddot ill middottIIlIlOl ~1It tlWIIJI( my U)t PIl (tlIHatcl WIth tl1l lullh(t I tahle lJ 1hln 1- -1111 tIll (llllstlOll of nny p()~iblt tITptt of XtIIl11 diflp]lws ill ((JlllPllttUliollS of 1l-in lil lolutioll alollJ with till 1lIltbpl TIU data ill wbh +ho on tIl( hn~is of (olorilllPill ladillU thaI tll( IIUOIl1t of lnbbll Plllipirntld 110111 Ilwthyl olnlld kptOlll olntioll IJ 1li-jHlllnt 1l)04 in 1-llltlIllt ethallol)- not amlll hy thl llllNlI(l of llvin aU1ouut of llins inolution bull
-----
26 rECHNICAL BULLEfiN 920 U S DEPl OF AGRICULlUHE
100
90
80(I) C)
z Ci 70 UI a 0 60 a ~ UI ~ 500 ~ 0 I Il 40
30
A 20
0
100
90
(I) 80 C)
z Ci 70 UI a 0
60a ~ UI E 0 50 ~ 0 I Il
4-0
30
B 20
0
--
--shy ---shy---
2 4 6 6 10 12 14 16
---shy= ~ ~ shy
-
2
025 05
10
15
20
25 -30
35 40
SO
-60
=70 80
16 20 2224 26 26 30
OS
- 10
IS
20
2S
30
35 40
-50
-60 -70 -80
bull MGPE 25-ML
VOLUME
bull
MGPER 25-ML VOLUME
Florm 12-EtTld (If till1l or Slllldill~ 011 light transmittallce (01 (A) gUllyulc lnUIl(I plccipitllitd frOIll llltt h~l isobutyl Ielollt solution Ily neidilic(l ethanul bull null (B) gUllyule ll~illii pre(ipitated flom aeltoll~lllcetOlll-Cl])osolY( 3-7 solushy11011 by H(illilip(i l1U (HPlldillg~ nt -lIlillult Ifllpluls 011 Evelyn photoelectric colorimellr with jU-lllp tlllll alit U-1I11 npN(lle spp also table 2)
bull
bull
RAPID PI-IOlOMEllUC DElEnMINAlION OF RUBBER AND RESINS 27
TADIbullbull ] 4-ReZation of amiddotmount of middottbber pleeipitate(Z Oln metltlIL isobutyl ketone 80lutions by OS-pereent H 2SO in 95-pere(lIIt ethanol to umollnt of resin8 udde(l U8 indivute(Z by colorimetrio readinU8
(Rubber ami resins cnlculntcd on bnsis of amounts in 5middotml ullquuts of extract from 02 gm of tissue in a 2fllll olumo( bull
Hubucl r~cocrell whcll rcsins nddcd as IndIcated Htbbor al1dcd (pllcollt) ---shy
__________bull_________ ~_12rpcrc~15011crccllt 7511crccnt IOOpcrcent
PerCtllt ercellt Percellt Percellt Percent o o o o o) 50 250 263 252 25000 500 500 500 500 700 750 750 751 749
1200 1250 1250 1250 1250
EXTRACTION TEMPEHATURE AND TIME
Typical experiments to detllmine the time required to secure maxishymum extmction of rubber und ltsills at 115deg U Ilre sUlIlmarized in figule 13 the solvents used-methyl isobutyl ketone for rubber anrl Ilcetonylacetone-cellosolve 3-7 for resins extraction-are very eflicicnt since under the conditions indicttted maximum values were secured after 30 minutes of ext1llction The most eflicient liquid for the bath (lig 1) used in extrtlcting rubber or resins is ~ high-grade cylinder oil (S A E ~O) The sand bath and such liquids as glycerol have proved unsatisfactory
RUBBER AND RESINS STANDARDS
According to the National BULeau of Standards 1-_ lhclc Is no gellcrnlly recoglllz(d standard lIIutcrlul [ior II rubber standard] The rubber hydroCllrbon ill llifferent samples of conmlcrciul smoked sheet or pale crepe from heclI pluntlltions nries from l~ 10 04 llercent of the totul nutletmiddot the most 11Ioruble conditions Of preparation
McPherson () has described a procedure for the pLeparation of pure heve~ (Hevea brasiliensis (H B K) MueH Arg) rubber from crude rubber or latex In the absence howevcr of ~ generally recogshyn12ed stalldard for rubber hydlQcllrbon [caoutchouc (CnHUs) xJ the standard adopted was that of the relnthely pure product secured from gunyule tissue txtractiotl nccording to the Spence-CaldweU method (5) or the motlified PIOCCdUlU of Hohnes lind Haasis (p 2) The details for constructing the calibration CULes are given on page 10 Standard rubber samples apparenl-]y can be stored for a long timc under the conditions des(libed on page 10 The duplicate colorimetric lendings for glULyule rubber newly extracted by the modified SpenceshyCaldwell method were ()J2 ench as compared with US) each for the sample extracted by the same method but stored 1 years In each case colorimeter rcadinllS were made on mixtures containing 2 mg of rubber in It 25-1111 Yolume
The selection of tt suitable standurd for guayule resins presents some dilliculties Tll(~ acetone extract of gUllyult estimated on (l gravishymetric busis~ for instance proved to be variable depending on the type of tissue sampled or season of sumpling because such fractions as
COllllllunlcntion dul(lt1 Octohtr 22 11H3
28 QECHNICAL BULLEQIN 920 U S DEPT OF AGRICTTIIlURE
16~==========================115 shy
14 bulli= 13 z ~ 12
ffi II Q
10 c w 9a w
8gto () 7w a
6a w
5en III ) 4 a
3
2
A 00 5 10 20 30 60 90
14~------------------------------------------- bull13
i= 12 z w II ()
a 10 w Q
9 c w 8 a w 7gt o () 6 w a 5 If)
z 4 If)
w 3 a
2
o+B~~__~__~____________~__________~ 5 10 20 30 60 90
HEATING TIME (111 NUTES)
lllGUltE 13-lDffect of time o( lICntillg O2-gm samples of gunynle tissue with solYlIt nt llfio C on lo(OVl)ry of lllhlJer alld 1Isim Lt HlIhblL extracted with methyl isohntyllwtone B resins Cxtll1cted with aCftonyla(etonc-cellosolve 3-7 bull
chlorophyll are weighed along with the resins in the acetone extruct but are not estimated by the present photometric method (fig 0) 1he use of a diffeJent stanclttrd waS therefore indicated
bull
bull
bull
RAPID PHOTOMETRIC DETERMINATION OF HUBBIm AND HESINS 29
The resins standard selected is based on n relatively pure source of resins the rcsinous exudnte 011 the stems of guuyule plants IJldimishynary expeliments with the resi nouS cxuclate from diffcrellt gllayu Ie strains of various ages indicatc nHlt there is little YaLiation in this subshystance on the basis of Colorimct(r readings 011 2-mg aliqllots of 01shypercent solution in It 2i-ml volume (tabl( li) Expelilll(lnts have shown that the air-dried (xuclate contains 3RtOH p(Ic(nt of -volatile matter This material is l(latiyt~ly stablp ill (OlllpoBition and is npshypurpntly on ly slight ly hygroBcopic as shoWIl ill Ia bl(1 1 Tlrp Ipsinolls exudate may be jJleplpd in two wayi-i fl liSP as a stallClHld-(l) the clpan exudate is clripd iol Ghouls at ()1deg C at W indlPs of a(lIum Hnd aftclbCinOglOund ill a molfalis 1)I(spI((I intn airtight COllilinel OL
(2) tllP Cx7lclate is clissolllt1 ill a(lhllll and filtplpd PlactieaJlyall of the acetm1l is thpn lYapolntwl olt OPI a stlam or atCt hath and Ow residue is dripd ground an(( PI(sPIld as ill tllp fin lllethocl Tlwse two prepalHtlolls a1( (ompalpd in ta hlp ) 111( (((tails fOl ~t()lil1g the resins standald and (onstlllcting the calibration CUITPS alc given Oil page ]2
lAIIIg fi-CUIIIllrsoi (lJ lIr-dr(1I IIIIi 1((11 II II-()I-tr((l l(sil~ 11111111(8 of I II 1111Ie
[Colorimetric rrndill~s 011 1~I11 phulll(Iclrie eolorillJct[lr with i~()middotmll (100- to iiOIIIIl) fillcr [lnd 5-1111 lIperture preeipitantl part ofO5middotPIrctllt 10 to 5 paris of IIOj
nupliclllc(oloritwt([
nIl(lin~s (hIlSlcAg~ ofSlmillXo JrNliltlCllt of fPsiJI$ L1Xtlrlntp on 2 IIIg ofplanls fllsins (XIHIIlt~Jwr 25-1111 vol
tII1(1) 1
leflTs Various _ bull ____ bullbullbullbull 3-9 Colll)Josiltrlairmiddotltlricfl bullbullbull nf)2 002
])0____ bullbullbull _bull __ _ bullbull ~-l Composilld (ri d at n5 C in aUmiddotimh lWUUllJ for l (jOuj(ja hours])0______ bullbullbull __ bull ___ bull 3-0 COJIlpositld disso]NI in neptolll f1l1erNl fl(lf()ll( GGO i(jO (Ivaporntld olT OV(1r Stpl1l11 halh TesidlH drl(ld I1t fi5deg ( ill anmiddotinch VIl(Unlll for 0 houlS bull
middot106 __ bullbull _ Jir~c1rild_~_~_ _~_ ~_~ _ ~ ____ _ __ _ OUu GOifina_~ ~ _ ~~_~ ___ _ _fln~ ~~ ~ ___ ~ __ 6(imiddotI tiliA H)[_ ltlu bullbull i18 tisSflOabullbullbullbull__ bullbullbullbullbullbullbullbull lt10bullbullbull _ tillO llitO406__ bullbull __ bullbull __ bull __ __ lt10_ Utl2 fon591_ fo__ bull liGa oOa 406bullbull _ __ lt10bullbullbull_ li5S OM
j Ph( vnluls in Uw Inst COIUIIlIl indieatp thnt gunyulp fesinous (IIHlnt( wlwtlwr dfircl hi Yn(tlLJ1l1 wilh L~ perc(nt loss of volntllt wutl pr or tWl c1rild giVPd npproxil1lnh1ly t Iw snllw colorinwtCr rNHiing- 011 till busis of aliquot~ cOlllniuiug 2 IJI~ of flsillS lXIHlntp l)tIf 25-mI volultl( Ihil- illdicate~ thl11 Uw UITW IJ1flS~ of olnshytile mntl(f prt~(iJlitnt(d gins npproxilllntlly Uw $1II1l (oiOfirnl1tlf ftudiTlJs ns tho ftsidtw A pnlill1jllaf~middot (XIlltrinllnt indicutls thlli th VUllltill muller l(lIlSists of thl Ilrplne oil fmcl ion I5-(1Il gtnplls or rlsitlOtlS (lxudntll gnvll by stPll1U distillation nn Uefllgl of 011111 of jl(lfPlIW oil with npproximHte tilllsity (If OHIi lind lhus rrprlsll1ll( IlPIJroximllt(I~ 01 Jerccllt Of t he original weight 1hls lllrClnlage complrcs wllh 38 llltrC(ntlost by drvinI( in IICllnllJ
aSplusmnUH perceilt or orlginlll weightlosl
The wailnble illfolJllntioll on tlH (ow-JitlPllts of the gunYllle r(~shyillOllS exudate alld tl1( HeetOlIP ext act of gaylp ti~slw is sllIllmarized in this paragraph lYalttI (u) alld also Hangcn-Slllit lind his coworkshyers 16 reported that 20 percent of the resinolls exudate from gUltyulc stems is parthenyl cinnamaie (CHuOH=CHC020 11JI2r) Steam disshy
15 (OIlIJIIIIUicatioll flom A T Haai(II~l11it llId (0011(11 Calif0111 ill Tnfiitnte of Tccllllology Past(IlIJI Jhps( wOlken al Htud~ing the COTlHlitlllllts of the acetone extract and other conlltituellis of guuyule
30 TECHNICAL BULLETIN 920 U S DEPT OF AGRICULTURE
tillation of similar resinous exudate in the writers laborntory has yielded approximately 4 percent of the whole as the telmiddotpene oir fracshytion Haagen-Smit and his eoorktrs nportec1 thttt about 25 percent of the acetone extract from guayule branches is parthenyl cinnamate and 6 percent of the bark (ltortpamp-phlotm) extraet is parthenyl cinshynamate These workers fm-thcI reported that 25 lwletnt of the nc(shytone extract frolll bLllllches is a compound with the tlI1pilicaL formula CBoH400a 1 percent is a compound llwltillg at 2P to 2T5deg C and 1 percent of the extract from the ]eav(s is tl (olllpoulld nwlting at 100
to 1710 1Valtei (6) reported that 3 to -l perc(nt of the tI(eton( txtract
of leaves and flowering StPIllS of guayulc eonsists of waxlike substances soluble in olgallic soln~nts but insoluble in at(l and (on(ent1llted H 2S04 The flactions mentioned on the basis of (onHLTutle esti shymates of amoullts actually isolated tlecoullted for about H ptIcent of the totalncetollt~ so]ubles extracttd from tll( guuYllle 11 rub The other constituents ltlilaill to be i(](ntifi(d
RUBBER AND RESINS CALIBHATION CVHES
Typical culibndioll Clllves iol Iuhbpl and I(sins bas(d 011 (ldtLminttshytions made nccoLdillg to the plocCdmC outlin(d 011 pages middotb to 1G arc shown in figulPS 5 and 1+ The spCdlopliotoll1lttL en (OIOIjlllctCI readings are plottCd on s(lIlilogalitllllliC pappi ag-ail1st (Il 11IbblI (011shy
100 ~ 90
80 ~ 70 ~
z 1amp1 0 II 1amp1 IL
1amp1 0 Z
60
50
40 ~ltI 30 ~ en z ~ ltI II ~ 20 C) ~ oJ
10 o 2 3 4 5 6 7 8 9 10
RU8BER IN 25-ML VOLUME (MG)
bull
bull
bull FI(lURE 14--Ctlihration curve fotmiddot gllftYlIlc lubb01 (Hct(lings Oil COIPIIHlII tlOl1hl(
monochromator SlCClrophotolllet(r with 7fiO-11IL Illtel alld Hllp Wll ( IHlll()
bull
bull
bull
RAPID PHOTOMETRIC DETE~MINATION OF RUBBER AND RESINS 3]
centrations From a casual inspection of these CUlTes it would appeltr that Beers law does not hold Actual tests indicitted that Beers law was applicable only within a narrow range in the upper portion of the curves The analyticlil results on the basis of photornetric readings nre therefore calculated by direct reference to calibration curves or from reference tables of equivalent values bllscd on the cnlibllltion curves
Calibration curves for kok-saghyz alld heyea lI11tulltl rubbers and Buna S (GR-S Chem Gum IV Goodyear) and butyl (GR-I Standshyard Oil Co Protoc) sYJlthetic rubbers are hOWllil1 figure 15 The samples of kok-saghyz rubber were furnished by the Diyision of Rubshy
100
90 ~I) ()
z 0
1amp1 a
~ a
80
70
60
s 1amp1 ~ ~ 0 ~ KOj-SAGHYZ 0 l Il
50
HEVEA~ ~
40
100
90
~ 0 80z Q 70a Co)
a 60 ~ 0 0 x 50Il
40 ~----~~----~------~------~------~--~ o 2 3 4 5
RUBBER IN 25-ML VOLUME(MG)
FmUIlE 15-CaJiblation curves fOl kok-snghyz h(YCII Bunn S lind butyl rubb~ls (Readings on gy((yn photoelectric colorimeter with i20-lIIp filtpl and 6-ml aperture)
32 TECHNICAl BUIJLETIN [)20) 1 S DEP1 OF AGrnCUIlfURE
Iwt Plant JIl(I~t ignlioll of thi BlII(un and (1( l))(parcd according to 11( SPltI1((-Culd (]] (6) PIO(((lllll Hlpt pal( CLPPe was (xtmch(L with acetone blI()Ieit W 1I(gt(11l a ttnlldal(l
SEXSlllVllY Ol~ llETJIonS
By lip pIO((l(II11P olltlillP(l 011 ]Hlg( +n Iowa (lOOl IIIg (11 1111i(l0shygmm (gHlllllla) of 1hblI ill a 2)1111 yoltll1ll (all )(gt dltpltld Oil tltl Col(man (lohlP mOIlWhlOl1lHlOl l-I)((t 101 l1lOt 0111 ci( I ill1ilnlly 001 mg of Iublwr ill a 2J-1ll1 n]ulllP Illay bl Ilad Oil till EnI)1I photoshyllectlie (O]oLillllt(I Thll ya lllll- 011 tilt IHl-i- (J I (xl ad iOI1 fmlll 02 gill of til-lI tH(JI(lillg to tllP -lllndal(l jll()(pdull 1(PIPStlIt IlO()2J tlnd 002) P(IT(lIt of llIbl1ll IPI)(((inly bull1t1lollgh -lI1t low allils can be d((d(middot(1 il lIoullt1 Ill IPtllizpd thnt till PIIOl ill PlI(Plltng( or tll( al110unt dltlIllIilll(J i ltlatlpl high ill tili PIY lo Itlllgl 111 aetllllllladie(middot Ill( lopl lillliL 111)(1(1 lIw (ollllil ions of tlil ]lI()(lltlIIIl u ol1tlinpd ipt at l11 11I1 or 1111gt11(1 illt i-1ll1 Ollllll IlPIPltPlltillg 01 p(gtl(pnt of JllUiJtL un tlll 1Hli or (xlla ion rlOI11 II rlll of tisSIll
EIlIlOH COSIIlIHIIO
In Oldpl to H(IIp ill )1lHtPltt pl((iioll illlpIi1I- it i lH((SSHI to slnlldHIdiz(i rigidly 111( Pl()((dlll( 0 illdi(ntpd Oil pnglt- - to J( If lids i dOlH tlip lXIHlinwnlal PIIll is t(middotdllld 10 n ndninlllill
Illlt pl(iioll of (hI ]lIPPllt 1IHllwd Oil til basi of ]llllP llIllJt1 alld Ipsinssollltions call hI jlldgl(J 110111 figllll Hi lileh lio- til HPIlIgl d(intioll oft -illgIP lI1lnSIlIlIIIlnt in lHi((lltagl of Ill( alllOllllt 01 Illhshy1)() 01 lpsins d((PI1I1 iJlld TIl( (1101 PlI(Plltaglt H1( gi (1 101 OJ) to
RUBBER IN 25-ML VOLUMEMG) 004 01 02 03 04
i= I I IZCtOW
fbA ICtU CtCt WW a
01 02 03 04 05 06 07 08 09 100 = RUBBER (PERCENT)
RUBBER IN 25-ML VOLUME (MG) 10 20 30
~ I CtZ
bBOw Ctu CtCt Ww o I~
010 50 100 150 200 250 RUBBER (PERCENT)
RESINS IN 25-ML VOLUME(MG) 10__ __3-0_ 40 50 60 70 60 90 100--_-- 2_-0
Ct~ -r- 1 I OZ
WCt UCt b C wCtW
a o I I 150 250
RESINS (PERCENT) o 10 50 100 200
bllI 1tI W-Yllnl dtd1 ioll I I 11l1 11IlI11 1(111(11 1 III Plll- IlIIIlol1 01 IIim~
bull
bull
bull solution Il basis J o golH of tiSSII (JlILCl-nt (11(11) for (~I) (l)1 til O 1I1
of luhllpl lin 1 III I (I Ill of lUhlJPl nllll laquo I J to 111 nlg of IlSlllgt (Itllillgs on ]iYllyu pllolwh-llrk CO[IJlilll(-(PI with nOHIP Iiltlr lIntl U-lIll allcrture)
RAPID PHOTOlJElRIC DELEHlllNAllON Cn HUBBER AND H1~SINS 33
10 mg of rubber anel1 to 10 mg of resins in a gJ-m1 yolumC For
bull
bull
bull
comparative ptuposes the leslllts arc also calculated on the basis oJvershycentage rubber OL tltsills in 02 gllI of tissul As WOlllL be expcet(d the error increases sOIlHgthlf for 1(lali nmiddotly low COlHell t1llf iOlls oj rllbbeL or resins The curves in figure 1(j s1l0 that ill til(gt Illlge Ol to 10 pCrshyeent of lubber the elTOI rangts Jroll1 abollt Ll to II) ]IlC(lIt abo(~ this mlllc tIlt (ITOl d(((ts(s to (ollsidlItbly ltmiddotss (han 1 1lICPllt of tlH mllollnt ltl((Lmill(d Hil1lilally in tlH (lISl of l(sins analysis (fig 10) the ltLTor is (onsit1eIubly INS than 1 PlLllnt ill (he lallgp of 11 t~) ~() penPII t
In nil ([lSl of lllhblI alld (sins lx(Inltpd tIOIl1 (issups Ol addcltl to tisslle lxtlads (s(( tabhmiddots (i H) illyolillg ll01P o(lllntiolls the eLI01
is hig]wl thun that indilHtld in figllll ((j Im pUIl Ill )])p I tllllllsins solutlOII
COlllUCIIOXFOH IXSOLl-IlLl~ Ilgsqgt(Jg
111 th( Jllo(pdulP ollllillPd 011 paw I till illsolllhll isSII Ipidll( tflpl (xttlw(ioll is (Ptill tlw lIask l(lll till xtlct i l1wdp up to yoltlllH It is not rOllPllipnt (0 IPt()PI qWlIltitati(Ir III(lw[olH a 11(1 pllooll extlnlfs of guuyull I is-lll alll thl1l main t11l111 up (0 YOIUllllmiddot bpCaUHI sllch all additiollal stltp wottld]) tillll-C(JllS11ll1illg Th( Iogiea nll(gtIshynntin is to mnkp tltl lXtlUCt Llld Ipsidup lip to OllillH in till original flask andi llPSStllY 10 llwlno tl OIIpdioll wlHIl (allIlnting [hc llshy
Hults f(JI [hl oll111lC displupd hy till ins()lllbh llsidll( III it l)picat (IXpednHllt (ollsisting of Jhp lppJiea(iolls if was Iollnd llftt at ~iiO ( 02 gill 01 Iuhhll pillS IPill-fl(( lisslI(gt (lollpdll fot llwistUlC ou basis of dlyillp ut lOW 101 ) llOlll-j (lbp(ld only t~ llllUll voiul11P of OOk7D~- OO(lOO(i Ill of lllthyl bolnl(yl 1lIOll( (lplhlli(al-t(Tnltle sp gl () Ii I ll(Hli (j at ~)) -gtitllP tl1(gt 1It101111( () r t is-lIl xt Iadld j sl1lall til( PlIOI dul to Ill(gt insoll1blp Ip~idll is slllall III [0111 ill( wOtk it (all lJp diIpgal(ll(l
]hcon~lIY OF HllIllgl AiO HESIS AIH)gl) TO EXTlIACI OP
GlYlLE TISSlg
Tnl)ll G L(IHpslntillp (ypi(nl llld(~ SllOS (hat all a plngl of HIOK PlI((nt ot lltl pltl( Ilhl)(l acldpd to tllP Itll h iolJut1 InmiddottcJllP xhnet
of guayulp tiSI1( WllS 1l((PllIl Tlli nllintioll flOlll (olllplpU I((OYshy
PIY i within flll pxp(IiIlHuttllIIOI ~illli]llly fnbll Ii llows thn 1111 llYlIUgl of 1O(1~ ])(I(Pllt of gllllYllII 1(-i1l- add(d to II( (pllosol( (xshytrae of IUllY]l t i~HI Is 1l(oPIPI
THl~ (~ Hf (Off Ill of 1111)( J OJ I~il~ lItfI(( In ~(JI1IJk~ Ilf (111 [lI1Il fI2 lIII
0 tlUfllllit i~~I1
Instrument
---- ----~---- bull shy 1(1
Colemun ruono~ltrOUlllt()r 2t) II sJl~ctroJlhOL()lIIeter with 2tJ I iflllllI wnclength Fetting 21 II nntl 0-1111 WU HI hUJl(L _ L U
Ill 7Evolyn photo~lcclrie (olor JU [ imctcr with iO-llIl filler IV (I
H1 0 t I I
llImiddot lUn WII 1011 HIO Wn mil lUulon
10 JIg1111 IUI ml lUl anh Io aLn 111)_I ) III li lU It 2) deg wn2SU DD
Irl JIll II IIr II US II
1110(1 lULa lUI IlK) IJ WU
I( llI Htl tNI 1(111 2tlNI HI 0 221) lllil t2S 0 1~ 10 1~13
In (I 2117 I
10U 1l(J ~ 4 _H_j ___
9middotJIlJ5 10115 10 00 lUU5 flUU 4li (tl03 9(11)
leIlKl 1l~)5 lOOU l1KIr JOIS un 003 OIl Ii
34 lECHNlCAL BULLErIN 920 U S DEPT OF AGRICULlURE
COMPARISON OF PHOTOMETRIC A1D MODJIoIED SPENCE-CALDWfLL METHODS OF RUBBER ANALYSIS
Guayule samples were analyzed by the photQ111etIic method and by bull the modified Spenc(gt-Cnldwell mcthod The values in table 7 represhyselltativ(I of typical results indieate It -atisfactory dcglpe of conformshyjty between the two methods in thl range of tiSSlHH with llHHC than OJ) percent of rubbtImiddot On the bnsis of the amounts determimd the results in this runge for the plmiddotts(nt lIlcthod ayernge apploxinHltely j percent highcr
~LAIII~ 7-(oIllJl(i~on of lltlllrIic (IIri mOtllinl SJl(II(r-(ulri-wall IIIrtlwrl~ of rlrrlIIillillfl 11)1)(1 COIIrll of UI(III
1 Flowers frllm amiddotmonth-oltl nursery plants
YAIIIATJO- OF SIli(LE DETEnt1NATIONS Fnoll TnEIIllIEAN
Rllbbel (Uall8i8-Thc plcCision of thc pLcsent method when gunyule tissues Hr( nnnlyz((1 for rubber may be j udg(d flom I Ill datil presentcd in table H TIl(se dahl -how that thl pplCPlltag( uriation of single determinatiom from nwan yullles with low standllrd enolS ranges from less than 1 to 4 p(gtrlent
R(8in~ wWlsi-r-s lndi(a((1 011 page ~j he INntlts s((uled hy the present phoolllttric nsins llHt hod are not tliltly (olllpalable with those of the grtLVimetri( ncetol1l-cxtlt1(tioll II1etho(l Thjs made it necesSllry to selc(t another lalibllltion staudud-tlll Ipsinous exullate from gullyule shrub-thut gies relatively COllstlllt photometric readshyings (table 5) The resin (olltents of guayule roots branchcs or leavcs usually ran(~e from about) to 1-1middot pelcellt The ple(ision of the present methotf WhCll gUHyule thslllS lIe analyzed for reins may be judged from the datalHmiddotpscllted ill table 9 1h(se data show that the p(lcelltage variatiun of sillgle lhmiddott(Lminntions iLO11 meun ynlnes with low standard NTOrs rangcs from about 05 to 4 percent
bull
bull
bull
bull
bull
RAPID PHOTOMETHIC DElEruIINAlION OJ RUBBEH AND HESINS 35
IAIILE 8-luriation inclieute rubller (mallSM of [1wIIle tissue bll thc 1111O0Illclc metwII
Vnrlntlon~Ilbher I (rom mean
ierCtnl Percelll ~OU -22 ~ 25 +27 ~ 20 +18 ~UO -22---------1_______ 51110 0G6 bullbullbullbullbullbull _bullbull
10 ro ----=ii41075 -01 1000 +11 1010 +13
rlln HI itil 1l9~ 1_ ___ =-~~~
115511 ~ US -111 III II 1575 -13 115 b tiS -I a 111 h WlU +22IIM-(middot bull 11K -1Ja Illi c 1000 +03 1J5H1 W +l)7 ll1imiddot tl 1575 -13
Mcnn 15951 131
1102-11 21fJ() +21l102-h _ ~~)SO -17 1102-c bullbull 21CO +21n02middotd ~OIiO -26
2 r~plusmn Il~ 21151 261 I -~-------bull---__ _~~_~______l-___--_
1 lhe$ 1111($ I1n (or SlIlIIllltS Stpnnltplr PHrilClld IIrtlrdlng 10 1hr prollIlIlr( OIiIIiIl(o(I on Imgt$ 4 to IC ~tcond nUlI1 hlr r(J)[ltnts stl1ndnnl llrrot of tilt 1I1(1111
1_1l1~ n-J(lri(iot in relli(Upound rpoundsins (lllalIsfs of VIOJII( lixsue b1 the lhomillric lII(lloli
-- ---~--- - __-------- shybull I I I I Varlgttton
_________~___ ~~lu_n_Jl_Q_~~~_____ ______I__~_o~S_J frOID lDean
Percent Percentgt458-1 ~65 +41IWtl-li 130 -a2Hli8c aliO +26S41i8-d bull 130 -32
1(-011 34I10Olifgt __ bullbull __ ~--====
li-9~2n 881) -06 li-9~2-b Si5 o ~HH2middot(middot S i5 -6$-H2middotd 000 +1
8851 054
O i5 +6 9 i5 +6 950 -20 U75 +6
H-liG3o-n bull -1 n-li6~b bull __ _ -IH-IWH +4H-l61511 bull -1
1tmiddottlU
62~-lI __ 62~-b ij24-( bull OH-Ji
(-Ull
I rll(St oluls nre tor separately ~xlrflCled SllllllllCS IlctOrdlug lO procedure outllned ou pages 4 to 10 i Secoud number r~prtgeulS stulldMd error of lIe menn
36 TECHNICAL BULLETIN 920 t ~ DEPT OF A(]RICCLTCRE
ReUUER A~ALYSrS I~ CRCOE-RcuUER PROOCCTS
Sew rapid photometric m(lthod~fol the ddellllinttion of rubber and reii Hi ill uaYllp ti--ut htp lllell pIPHnl pd oil pag( ~l to In A brief H1111111tlY of It similar rnpid llHthod fm 1I1hb~rllnltlysis of u1lulcanizNl tlIldp lubbll pl(Hlmtlt whielt i~ bn-(tldo on the prill o
ciples dehtilcd tlllLe follows Duplltate nt-gm sllmph of the finely cliyiliNl IlInttlitiup wlirllll out [~ei-()l (all hl lIf((tinmiddotjv INd to lt1iyidl till alllpl) TIll kltolll-olubll portion of till )111(11( tlrc di-olved a- indh-Htpd fot thmiddot lllnkill~ of -tlllHlunlluhhll olutiou Oil Pt 1II hut tIl IUlIp Hn lIn l-fplImiddotd 10 lHI-ml rolllllltti( fln-k antil1ltld(lup to Olllll1l The bnlulUp or till JllO(ldllll i- thatutlilllll on paWs -1- 1 IHI Ii 111( 1(111 1- nIP IXPIP--pd nil til IHi or Iw oligiJla w(lullt of I Ill (I11l1p-I1l11Ilt1 1)(0(11(1
Hupitl PlllimiPJojgtiWllllllllh llIltllOd~ fOJ Ihl llPtlmiddotminntion of ImiddotUlJbll tlnd 1(-illo- ill -111111 Illllph of gutlYllll tiUl IIll dl-eli)ed 111() IlltlY d~o Ill nltlI1lld fOl III Iwl Illhlwl- and l~iJlmiddotb(lLiJlg plant TIllt l[Olllhup hns nlo b(l1l ntuptpl fot IIH lltlIll1illtltioll of lllhbpl ill 11lHhrublwl Pl(Jdlld~ HIIl 1111 hI ndaptld JoJ IIll ann lysis of ynt1J(gt( ic lllbbl[- The llllthmb HIP 1gtn(11 fill tIll fol1owill plimiph- III Grinding
tIll PIOPlly driPl t i~lIl 01 Ul tillg tIll pnHhHt to tll l((lllilllllh~lel of filWlH-- til plllllit qIHlIllilnth( lXIIHtioll 01 IIlbhlI 01 1(--IJl- () llsing oXWllutld olnuh (kttoJls IIt(talp and() fllltil for LIbbel and IH(ltIlIlyptIJllIllIoolYlnJld-o flJllh 101 niJlsl with t(lathelr high IlPililig points 111 to n C) l]olle or in mixt tIll thllt Pll mit tlll rnphllxututioll of luhll(l OJ [middot(ill ill ~() to (l mi1lutp It r(latiwly high 1lllIllllltlltP Ill to 1~11 ) l) lllllipitntillu till luhblI OL Imiddot(ill frolll aliquot () f till oltn ion I IlIlllI-i () f Hlltabhmiddot pl(~(i]litallt (willifhmiddotd lthmwl fOl IIlhlHI Hild llitlifild lllr fOJ JP-illl t~) IIlHkillphotollllliilPIIIIiIlof PlllPlltal of liht tLaIlS mittUl(P lIftlI IlIlbll (II Il in PIlipitalioll 11 II WI( Iplllh thnt (limiJlall till PIIOl dill 10 xtralllOlh (0101 (till dptl1minntinll Iph jill 011 tIll dtwlopllIlJIl of H HIli rOI1ll tlllbidity 111 hpl than I (olot rI
jJlIlpOP-ofallnlyi-I ( p(lllil1thb IIllijOI1ll turbidity or 1llt[lIinmiddotd d(ltl of jgtIp(ii(JlI l)~ lIltlkillU tIl plllltollllmiddottri( ntdillU al tandinu tiJlH~ (dlllilll wlli(h IhlllH(lill-- IP 1llutinmiddotly tnhll) t1ll1t an hlsl~1 oil the (oJlItlIlllItion of IIlhlHI Ill I(ill (lIPIipitat((L
TIll -I(p ill till jll()(Plhul HIP 1-- follOylt (1) 1l~UIIL uJ1lplls of thwl UJfJlllHl (II tliddl(l HUt dlipd 11Illtplial an lXIllltel with11 Ill of till nlnll ill t (oU tlllltIPlll[gtPImiddotatlup oil Iath at 11 Cbull fol 11 minutl I) iIP1lIin(middot(lohd til( (XUtllhllll Jltldl lip to It middotml ynlmlll til( (nlifild by (Illlifllgiuu HlId thlPl IlI nliql1ot of tIl (IalioPlllxUlltl nll Uillltlmiddotll(t to l-llll OIlIIlIllril fiuk- (1) For a trial Ilnditlg 0111 III tlll j liJmiddot~t IllHII IIjI to Ohlllll with lilt Pll shy(ilitnnl a 1(11 it 111 (Dod fill llli lIut ( ptotoJIIltlil IPtlllillg-- of pllllntnl or liuht tlUtllIlillal(I oil n (lpel OphotnJlllllI at rase hng-tlt (If 11 llJ Ill Ol It lollllil1lPtImiddott lloyidld with tIll P10]11 I 1110110shy
Ihlolllltt hmiddot Ii1llI Olllhi lIatioll for -1IpItillg UJlproXilll1l tply Wtl P ]Plwth )0 mp are HHlltk TIll Illldillg lliJtaillld fol tIlt 4-milutl tliall(~ll-
bull
bull
bull
RAPID PHOTO~IETRIC DETERIINATIOX OF R(BBER AXD RESINS 37
ing are referred to a table of equhmiddottllut~ previously p1(pa1elt1 on the
bull basis of 4-minute reac1inJ~ for tilE nmge of lot1telltlatiol1- of rubber or resins to bE elHOlll1t(led tmd gidn thtmiddot -tnnlillfr tillIP fill rUbbEt or resins aiter prE(ipitlltiol1 lwfolE photoIllNliI j(tltlill1 un IUade The r(middotnmining dllplllatt aliquot lll then HHllil up te ol1l1Jle and lpoundadillg ale marle ut the -tandillfr tiUlE iudklltll ill rhl tall1lmiddot for the final r(adillg~ -1) 111( milli1lnm or p(tCPlltllt- of lllhbpL (II 1(-in pr(s(nt are rpadholU a prlpan(l table of lquiltlput for tlll photoshymetric readings h1~l(l ill pnell e1-E on pxpPlilmlItal lhln 1111(1 u-ing as stimtlltlds pure luhbll in 1l1bbtl milllYb aIHI guaYllh ll-ill- lxIHlatt~ in resins detNIl1111lttion I
LlTERATlRE CLTED
(1) lUnSbull 1fl36 THE mURMIXTIOS IIF IOTA RE I III OOl THER llT~II
F1 bullrol IlY U(T1l0fll UfSlfi ~rrnrl r flm lt1 KEYS TI Bill Chern 114 44J-l59 illns
t1 ~ICPHHlObullbull T 1J3bull~ lUTHOO roa THE PtRInCAnu Or a(lIUl IRrIlHU It of TIn
PLRIHEU Htllllflt [ i Bill lallllall 111 Rmiddot 711middotj iIlus
I ) RHBERG P B Ul5 A METHIlO Or ~u(ronrll-nl Hi tIII rUIl[1 f71 ii illlI
bull 14 Hoss W flbull and HARDESTY J O
llH IR1ltDII Of HfITilIZfmiddotR DllIJS ltt 1 Yl fll Off gI bern JIIIlI i ~middotmiddotlf IIl
101 SPEltCE D nnd CuoWELr ~I L 1933 DETER~n-ATIOo OF RtBBER Ii nrllllpoundRBfR Iusr 1uI II1 amI
Em~ifl cttIliIa~~ r Ell i 71middot7i l11 (HI WALTER E D
1U44 ISO~nlS OF PRTlltSrr 1trHpoundV bull l UI n W lHHt (Tnmiddot 1ETS FROM GiYI l~iIl lItr Clttrn SII J UI titJ middotn9--C1 ilIu
17 J YOEbullbullr H lO~( roLORIlETRT 771 IPmiddot nl -W Yurk f H Plrwptric hmica
naly-II rimttry lUll XphHHlnmiddot~ y 1 1
11
HI) ~ fPHELolzTRf 57 111bull Lin xw Yk t H lt PhmeHt CblUlmiddot ila AnaiY~l~-(H lithrry and XIhmiddotILpfIY Y wirh enomiddot rrJlllrjr hy H KtlJnJU11 I
t~1I --- and ~ARVER L 1f41 nlua-w ~in L liLhr IS IP ll~ XIW Yrk
bull For-sale by th~ ~a~fr1nt~nf1ent Dt~c~~ogtnts-~ s t1i rArnn~ut Pn~~~ tJffieshy
Washington 5 D C bull Pl lU ~nts
14 lECHNLCAL BULLErrN H20 U S DEPl OF AGRICULTURE
drying as indicated for fresh exudate In all ClSeS the products are stored in airtight containers in a dark coul place
The usualllnge of resins from gunyule tissue is about 2 to S percent on a dry-weight basis For work with this plaut therefore on1~ one curve is needed A typiCallesins ealibrntion CUlTe is shown in figure 5B
PnocEDuuE J~OH RUBBER ANALYSIS
Duplicate lXiLllCtiOllS arc made for each tissue analyzed and duplishycate photometric readings are made for each cxtmctioll the final value therefore reportcdreprescnt- nn avcragc based on the four phoshytometric readings
Thoroughly mixed O2-gm samples of the finely ground tissue are weighcd for analysis on the basis of l11oistUlc-frec tissllc The samples arc weighed to an accuracy of 02 mg Oil an analytical balance The method of deriying factors for making eOllections for moisture in samples has been thtailed on page
The weighed samples arc trallsien(c1 to the 2-m1 volumetlic flasks with the aid of l-inch glass funnels and 20 m1 of methyl isobutyl ketone is added to each flask The contents in the Hasks are heated m a constant-temperature oil bath at 115 0 C for 30 minutes uncleI a yentilated hood rhe flasks are removed and any adhering oil on the outside is wiped off with Kleenex 01 H similal cellulose tissue the C011shytents of the flasks am cooled to a standard tempellltule (25 0 in the writers laboratory) in a constant-tempelutllre ater bath provided with a motor stirrer if available and made up to volume with the solvent After the contents are mixed the flasks are allowed to stand for a few minutes until most of the insoluble residue settlcs to the botshytom The extracts are then carefully poured into JO-m1 heavy-duty centrifuge ulJls so as to include as little as possible of the settled insolushyble residue The centrifuge tubes are stoppered with cork stoppers and the liquid is clalifiecl by centrifuging for 10 minutes at 2000 revoshylutions pCI minute The clarified lIquid is poured into 25-m1 volushyl1Ietric flasks plOicled with ground stoppers It i impoJtant to pour off the clalificd (dlart in lWIt a lUlllie that the ill8ol11ble cNi(hwis not Sti1((Z1tp A 1-in(h funllel is plncCd in the neck of the volumetric flask A filter stick (fig 2 D) is inserted in the centrifuge tube through he liquid so that tlH enlnlged palt of the gtiek seals off the insoluble residue and a small portion of the exmet in the cone point 1Vith the index finger the stem of the filtel stick is thell held against the side of the tube towllnl the analyst who holds the tube with the thulllb rmtl t11illt1 fingCl The txtlHct is thell poured off easily into the yohunetlic flask without distnrbing the insoluble residne The COllshytents of the Hasks are then ))ollght to the standard tel11pelatme in the constant-tempentl111e wnter hath
The reagent blank us(d wit h the spectropllOtoll1lter 01 (olorimeter ig prepared as follogtvs ) 1111 of methyl isobutyl ketone 01 other solvent used is pipetted into It 25-m1 yolumetric fiask and 01 ml of protective colloid solution for rubber is added the mixtule is made IIp to olume with acidified Oil-pelcent ethnnol and mixed again the rcquired vo]shylime of the mixture is poured into a cuy(tte or an absorption test tube
From each plir of tissue extractions to 5-1lll aliquots 01 the clarishyfied extlact at the stnndanl tempCraLule ale pipcUed into 2ii-m1 volushy
bull
bull
bull
bull
bull
bull
RAPID P1IOTOMElRIC DETERMINATION Ol~ RUBBEH AND RESINS 15
metric flasks and 01 m1 of protective colloid solution for rubber is added to each One additional5-mL aliquot from each pair of extracshytions is similarly prepared to serve as a key to the standing times for the final readings as indicated in table 2 These additional aliquots are first made up to volume with the precipitant acidified Do-percent ethanol mixed by carefully inverting the flask three or four times] and allowed to stand for 4-minute periods before the reading is made on the colorimeter Vith these preliminary rendings a~ a basis the standing times for final readings are taken from table 2 For example if the colorimeter reading in rubber analysis at 4 minutes is 655 then the standing time is 15 minutes
The two rell1Lining duplicate aliquots for eath extraction are then made up to volume with acidified D5-percent ethanol mixed by careshyfuIly inverting the flask three or four times nnd allowed to stand for the required number of minutes as established by the preliminary 4-minute trial readings (table 2) before the final colorimeter readings are made on the contents of the flasks
TADLE 2-St(llllliIlU time for variolls (OllccntratioIlS Of rubbcr or rcsins aftcl iJleaipitation bcforc colorimetric readings mc macle
[5middotml aliquots of rubber in methyl isobutyl ketone or of rcsill~ in ncetonylncetonemiddotcellosol e 3middoti both made up to a 25middotml volume with pr~cipitantj readings on lvolyn photoGlectric colorimeter with i20middotml (690to iiOmiddotD11) filter and Umiddotml aperture]
RUDDER I
Range of colorimeter Approxima(e S~nuling i Rnnge of colorimeter Approximn(e Standingtrial readings after 4middot range in conmiddot tJIIIG for trini r(adings nfter 4 range in con tifillnlOalcor minute stunding time tcnt In tiSSU(l Unnl I t I t (rending IIlIDU C stum Illg lOW _ tent III Issue reading
Percent Villlits II Perfe~lt Jfinul 955-999 bullbullbull bullbullbullbull 09-01 00 01-03S bullbull ~ _bullbullbullbull_ Jl-O9 10 743-954 bullbullbull ~ bullbullbullbull __ _ 43-10 30 1420-550 bull ~ ~ 137-94 5 6_3_9-_74_2__bullbull_ bullbull bullbullbullbullbullbullbull_-_---- 6__8-_4_4---___ bull ~ ~ bullbull ____ MQrcthan 13ibullbull_-~_ _ ____ 15_~elow t~ 2
RESINS -----------------------------~--------
957-999bullbullbullbull ~ 139-01 60 11419-amp11bullbullbull _bullbullbullbullbull ~~ 13~5-939 10729-956bullbullbullbullbull_ Ii 25-1 middotJO 30 ~gtl2-40(L bullbullbullbullbullbullbullbullbullbullbullbullbull _ 2025-1320 5 595-728~~~ bullbullbullbull 8 as-G 20 20 IBelow 292 bullbullbullbullbullbullbullbull- More thun542-591 _bull ~ bullbullbull_bullbull_bullbullbull 038-039 15 2025 3
I Precipitated with O5middotplrccnt HSO in 05middotpercent ethanol When the npproxilllull concentrntion of rubber or rcsins in solution is not known trinl colorimeter rend
ings atmiddotJ minutes s(nnding till nrc mndelS n guide to the required finnl standing time indicated in the last column III prncticc UII cxtrn nliquot is prcpnred for precipitation and thIs is discarded after the trial reading is mnde
3 lrccipitnicd with OmiddotpcrccntlhSO ill HO
PnOCEDunE I-On UESIliS ANALYSIS
The procedure fol resins unulysis is the same as that indicitted for lubber analysis eomiddot(I]lt that f he -olyent js acetonylacetone-cellosolve ~)-7 tht precipitant js O5-perctnt H~SOI in H 2 0 and 01 1111 of the protective colloid solution for nsins is added to each 25-m1 flask conshytaining the aljquot of the extract before the precipitant is added
PnOlmmlHlC INSlHu~mNTs UECoIUlENDED AND CALCl]IAlION
OF UESurlS
Photometric readings of percentage of light transmittance (T) ale made on the Coltnum double monochromator spectrophotometer at
16 lECHNICAL BULLElIN 920) U S DEPT OF AGHICULlUHE
750-111 wave length or renclings n1( mnde on a colorimeter pLoic1eri with the monochromatic filter eOIl)Il1l1tioJl for sllecting the npploxishymate wfLYe ]cngth at 750 1Il~ For routine deterlllinations the Evelyn photoelectric colorinwt(r ployided with aTW-lllJ filteL is IC(0l1111HIHtll
The liquid in hich the preeipitnted lubber uld rcins are susshypended is pOll(d very cHrdully down the ill~idl of th( clette o absorption tube to lLYoilllllC fOLll1ntioll of ail bllbblls Aft( LUbbet find resins preeipitation wlwn the EnLynpho(otkcllie (olo1imetll is used the readings are nmde nft(L thl standing tillll- hOWll in table~ It has been foulld (OIlllliellt to 11lPtipilatl tublwr 01 llsiIlS from the aliquo(s at ~-millute illtlLvals This allows stlilieipnt tillle to check the eOlolimet(r and to makc 111( lNHlings Vlwll a ehangp is IlltHk fLom onc rending 10 the l1lxt it is advisablp 10 llle the clIvctte 01 absorption tube nt lpast twkp with slllall p(Iltion- of the llllltiol to be leitd
After the colorimd(L lluding lta e becll Iltndp till IlIl II igllIlllS of lubbel or resins or thc lpL(el1hlges pnslnt in Ihe aliqllot are r(u1 from cal ibmti(Hl (urVlS (fig~ 4 and raquo or from plepn Led tables of eqllivallBts baecl ill each (liSP on (x[lerimPlltnl data The results are expressed as percentages of dry weight (S hours drying nt 100deg 0) of the original tissue The errol lltle to lCflyjng the insoluble residtH in tbe voltlllletLie pxtLHclioll flflsk wlwn the pxtrnetis being mnde up to YOlllmC is V(ly slight sinlte only (U gm of tissue is used FOLroutine allalyscs lhis ery slight eLlor mny be dislpgnltec1
EXPERIMENTAL RESULTS
The experilllCnlal reslllts Oil hi(lthp method- of tU)lPI and l(sins analysis a le based ttl( d icussld blicfly hlrehl
PHEPMINrlON OF SAlULES
No difliclllty was expPtitI1(ed in pltparing slmplls of llllrscly-glOrt guayule plants 1pss thnn ~ YPH1S old 101 rllbbpl alld IPSills analysis In the cnl of Odll filld-gl()n gllayull plants PIIOtS hopel mtty be introdmp(l by the custOlllalY Jlwrhod 01 pICpalillg Ihp sampl(s 101
HlutlYHis as is lwipfly i n( ita ttd ill th is s((tion Smh enOlS do llot nffCct the ])lCcisioll O[ t1H llwt hotls for LllbbtL n nd Il~in~ nnn I sis i nee till) are due solely to tIl( tbsup--ampling (llo(pdule in thi (a~e of oldeL field-grown plall TIll 1lllt1lOcl of salllplill7 fipld-gl()l1 plants JllOLC than ~ Y(HrS old thenfort Ieqlliles iurtlHl jnttigntioll
lgtAHnOILr~G FOR HEllOVAL OF UUVLgtS
Parboiling which (onisls in boiling gllltyule plants in water [OJ
8 to 1~ ~ninll(s ~s col1llllonl) uSNl a~ n llHans of Itlli rCnl()y~l prior to drymg nnd gllnllng It I~ tHI([())P ll(e~Sllr to ltItLeLnunc all possiblt~ eflct oi tlti PLOtPlllll( )ll (Il( final results Exp(liments have sh(nm that (helt i- fl Flight loss ill til tmiddotjght of lOO(S and 4(ll1S In I typi(ul lXpelillltll hlu1llHs of ~- ii) -1-ytII-old gllllll( pllllb were Italnd at randolll Olll ( of talns wa- paLllOil((1 and the le~es (1( haIHI-pi(kpd [lom till o( hpJ Ht Both pis (1( dlipd for 48 hOttlS at (i) C in a llI((lwlli(al (011((( ion Oyell Th( lpsult are SUI11111I11izNI itS follows
bull
bull
bull
bull
bull
bull
RAPID PHOTOMETRIC DETERMI~ATIO~ OF IfCBBER A~D HESI~S 17
Dry ucilht lust ill lariOilillf
Plaut (pcrcrllO 1 1 -I2 ___________________ _
213 _____bull _____ bull __ _______ ___ ____________ 12 2(
pound(111_ ______________ 1 R
4_______________ _______________ __ _____
A __ bull __ -_
The efred of parboiling on till final lllalp i SUllllllatmiddoti7(middotd ill figmc G Rubb(1 lecoYelY w(t about 1 percent higher for parigtoillltl plants and lEsills re(ovelY somewhat o-er 1 i)(lr(lllt 10Wlr The (Ii tference in lublH-l r((o-elY cannot be ae(01111tltlt1 fot by loss in dry weight _ due is to be found in a study of thE grinding lwhadol of a parboiled and an unpnrboilEcl shrub The grinding of the patboiled shlub in the hnml111 mill is much fadlitated and ns a rule for tissue with a rubber contCnt below 10 peteent llO aggregates of rubber deelop in the 1Il11ehinr during the (Jpelatioll Yitll the unpnrboilNl shrub some dillictdty may 1)( (lxppliellrl(l Sill(( sOllle of till sti(ky ltxlldutl Oil the plant may scI( u nlldei for the fmllHltioll of lublH1 ngglPgates Til is apparently explnins the npparlllt los in ruhbpl frol1l the llnpariJoiled hrllb as eompnlelt1 with thl palboilld (fig (i) TI1(loss in r(sins
II
RUBBER
10 f-
Ishyz LIJ 0 0 LIJ 0
9 --RUBBER -shy-------shy
-- RES INS -shy---shy-----_
IJ) 8 I--Z IJ)
LIJ 0
0 7 f- RES I NS -0 -shy0 LIJ III III J 6 f shy0
LEAVES REMOVED BY PAFltBOILING
5 f shy -shy - BY HAND PICKING
4 I I I 35 30 25 20
SCREENS (SIZE OF OPENINGS IN MM)
FIGlRE Ii EtIe(t IIf pnlticlp sizE Oil lEcorPQ- of rubber lind (iiil1s when lEgttiye wEre remond hr Pl1liloiling lind h~ hand pi(king ((Dlltrol) plllllt1lt groUlld in t hammer mill
6114038-46-3
18 TECHNICAL BULLETIN 920 U S DEPT OF AGRICULTURE
recowry from pUboil(d shrub may be due to the loss of the resinous exnc1ate during parboiling This exudate forms ns It SClim on top of tlw )iquol in the tank
On the basis of t1wse results the recommendation is made not to yaly the nwthoC of leaf lemoYal in any 011( lNi(lu(h project Then fltirly compalabh IcmLts should he obUiined
70 ~------------------------------------------~ LEAVES REMOVED
BY PAR80lLING ____ BY HAND PICKING
60
-I-Z 1amp1 0 50 a 1amp1 a
en 1amp1 gt1amp1
40en gt-CD Q 1amp1 Z
I shy 1amp1 30 a l shyx C)
1amp1 ~ J 20 I shy 0 I shy
10
O+--L__L-~__L-~~--~~~~~ o 10 20 40 60 80 100
NATIONAL BUREAU OF STANDARDS SIEVES (MESH)
FlGntE T-lJiMlil)utiun of l1Ultkh si~(s of gnll~II( tiSSU( JrIOllll(l in a Ball amp 1ew(1 mill to pass six dllIerNlt S(I(euroII 1(IlYes Iemoved from plants by palmiddot boiling 11(1 hand picking ((olltloll dpfo1iatld plants dried to 1I lUoistufl l0I1t~nt (If 01 to o) 1)(ICl1It ground tiSSlli IbalH1 1() minutes ill II ~i$hel
bull
bull
bull Kahn shuk(f
RAPID PROTOMETRIC DETER~UXATIOX OF RrBBER AXD RESIX-i 19
GHl~DIgtiG
bull Th~ entire pant 01 plant l)iHt a~(gt fl r(ll it pllllIIirU1ry lSillg fur J hours ntGi~ C prIOr tD t 1( plChmll1atmiddot rLlmhll III a II lItmiddot or n Ball amp Jewell mill ~n llltllysis of paldch lzP- nftl~l (oar-( IIindill shows that tlwy ar( about tIlt llllH fOl parbojlP(t awl IJllllluhoileu hrubs I fir 7)
The coalilly gloUllll ample i-- thPll Ildlll forI toUtmiddot at ni C afnr which it ha lllilobtllL(gt output of ~ llllut lII hmiddot- dptPlIIlilwltl by drying submlllpil- at 1110 fot hOtll- TIll 1 IIIIll i lltllt lmiddot0l111d hi a IluninHl mill TIll mo(lel uP(t in thi IIIk i 1I Hu IIIOilll mill as IllUllifill bv Hoss nnt Hartlet ( 1 -[1lt111- with n1ll1l1 pldushyrations ittI lilnbhell b rill HanlIolll V0ll11nHiol1 ElIillllmiddotrill (0 The size lutllihl11 iUlJnole So I ( 111m t ~ II t HUIII Xl) ~ I L~ 111m nnd So 4 lillllU1 11 ttllilhmiddotj 0 r tllP Imiddotlult~ p(lln-It willI t11(e Sll((IIiZtS with )arl)Oiltll awl uil)Jtllboiltd hrlll b lOwl1 in fif1l1fmiddot-- This hows t tnt 1middottttIl ~(I 1 llllll (Up jlllilnl IHlt that
r------~-------r--- ~ --r IHAMMER-MILL SCREEN
O~ NO1
NO2 ---shy U NO 3 ---II
I
bull lL
z
r ------ l 30 ~ gt III
i I Imiddot
i ~ I
I 1 I I
~ 20 I - 1 iii 1[ r 10 ~ ~ ~ I _ ~ I r A bullbull
o bull L-~__~__~~__- ~~ 20 40 60 80 100 40 60 80 100 200
NATIONAL BUREAU OF STANDARDS SIEVES (MESH 1
Yutln I i-tlillltiuli Hf pur id lZt f ~naY1l1 t middotnt r1 lI1 i ~ a hatlltlllI 1IIi11 to 1111 Lx IHtllllH middotIn Lt-anmiddot tIlllunl loy la1 litkh~ omrl t 1) tHul parbuih~ -t B ~ thmiddotfuliufptl ]~lahr thpt tu tt fit t 1 It+gtr-tt1 Jnui~tHn eunttlIt _~rnlitl tl~UP ltakmiddot~~ 10 UddU it~ 1 rtmiddot4~pt~middotK1~r ttakt-middot
bull So 1 gingt- 11 tt-liuin-Iy ltr~pl [lPlItl1tat of iilll 11animiddotImiddot- Eqltrimiddot tIlllll hnnmiddot llOWIl dutr fll llltldllllUU xtlutioH 11pound lnhbll lIl lP-ill frolll IolUlIl ~tlaYlllt tl-IlP by dlt IJwtmiddotlUlmiddot lItlilwd oil Ill 14 - 01
i-mllt 11111- -lwltld hi INd I li~ Ii I TIll lllhtIlttj of Itiu~ So 1 (lltll j thnt 11middotmiddot01middot lttwmiddot to amplil tltt Iollllli tilt art lpdnn ib
IntIIll ll~ i po--ihJI with tI lLllit Ilfltl[lll1t It honld l Plllplw izmiddotl rImt ilt tht h of -allllhmiddot with l lllblPl
~ontlnt of ill PPltllt til lIilll it i tlllt pll--ihl 10 11-middot t(1i Xli L
20 TECHNICAL BULLETIN 920 U S DEPT OF AGRICULlURE
Even with screcn No 2 difficult due to rnbbel tlcrltreCtlltiollS may be ob tl
encountered In thes~ caHeH it iH lWit to parboil the shlub fOL leaf lemonll and finally to dry to about 1 to ~ P(l((llt of tnoiibl1(l pound01 b(~t results jn ~rindillp in tlH hanmHl mill
It iH aclvlsable to provic1l thc hammer mill with a ground wire Hillel the presence of static electric (harges 011 tll(middot partkhH will ealls( Home of these to atlhelc to the inside of tllP (olltailWr OJ lila eallsc OI1l( of till pULticl( to form ngg1(llatls EIIolin lalllpling fl01l1 fhis SOI1I(I mlly be (onsi(h1llbl(middot
A1I10l1g the Holnllts with high boiling point that lIlay Ill IlHld in rubber anal)Hs I1IP Illllhyl n-alllyl ketolle methyl ioblltvl kptOIH diisobutyl (tOIH blltyl tHptate llethyl amyl 1Ittail (middotthyl(middotlllmiddot gly(ol diethvl (middotther and n-bntyl (middotthel (labl( 1) TIHse al( also I(sin 01shy
middotent but th( 1(~illS n1( held ill olution by the rll1)bpl pl(l(ipitant tthanol wll(1 lllbb(r is 1)J(lipitatNI (S(ll tabl(s alldmiddotl) On tIle basishyof the lxpHilllPlltH tll( btsf nil-round lolPlli -rol lS in 111( PIlHPllt method is lt1iisobutyl kPtonc wld(h was not IIltlllllfaltllllmiddotd ltIlling Vodd Yflr n A suitable Sl1lgtstit ute iH llHthyl jolllltyL htolt whi(h is l(porhd as llolltoxit UJ)
Clllos()IY(~ (ethykn( glYlol monopthyl (tIH1) blltyl earlgtitol (di(thyl(ll( gly(ol llIollobutyl (ti1(r)~ and acttonylacetOll( may be used as resins sohrCllts (table ] )
In the earlipr work with (sills analysis cpllosoly( alolle was selcmiddotet(d as a suitable solycnt Aitholllh (ell()~oh( alone is pxc(lllnt its rplllshytiwly gwatlL iscosity 1(I(b to bubbl( formation nft(I (SillS pr((ipi tatioll Thi- increased thp (xperimentnl (LTOI OIl of tltp othll I(sins solpnts tI((tollyla((tolH has the proppry of glpatly lNlulingshydH(OSity 11(11 altld(( 10 othr liquids This sohpnt tlHIeforl wa addp( to ((Uosoh( in slIflici(lJlt tlllIonnl to OPI(0111e the dinieulty On the basis (li~ex)le1inwllts ~ purts oi~ a(donyla((tOlll to I puts of (elloshysoh-f (bolll by olume) as Splldcmiddot(l Thp 01 hel Hoh(nl listed hutyl clLlbitol at l(llst the t((hnieal-g1lld( ploduct uSNl is appal(ntly not as good as eithe of t1w ot1(r two () a (ombinatioll of tlWSt
The SOlVllIts JOI liSt in tumlyzing artifkial lubbel$ hy tlw pr(senf method appllLently (lcllIHl on th(middot kind of llI))(I lIp-ityl (Jxidt is suitable Ol BUlla fi and hutyllthlI for butyllllbbl Tlwse reagents IlLe technical g1lld( Calboll amp CtllUil1t Ch(lllilai (OIP This Hllbjp(( hilS not bepn (XtpllHl(ly illwtigated by till WIit(I
PIIECIIIIJ-
All tlst fOl Ih( adlqlJalY or till IHllipitullb ll(Ollllllentillllll11Sl bl baset] on the plctisioll of tllP final I(snlts oiJtairwd with the methods The )redpittlllts s(1e((( n HpJ (xtcllsi( (xp(IimPlltatioll all HatiH~ factor (Hee fig Hi 111lt1 tabItmiddot (jH) Ext(IIin tllts llllTild Ollt hanmiddot shown that H Hatil-gtflltlOIy [gtIpeipitallt 101 1lIbblI is (li-p(IT(middotnt HzHO (c p reagent nil POll sp gl U-lmiddotJ) ill li-P(l(Put (tinmol by vohmlP liol (tllayul( Ipl-gtinl 1l)-P~ITImiddotllt H)~o ill Hl) by ollln( ii lL satishyfaeto7-y l)lp(ipitunt A solution of 1 palt of H~~o to 1 part of H~() (1-1) iI2So1 nnd abo yarious int(lIlIPdiat( proportions of tlllse suhshystanCPs giyp fait 1(511It8 but with till inlIptl(l ill [h(gt ratio of H~S01
~
bull
bull
bull
bull
bull
RAPID PHOTQlIEfRIC DETEMIlXATIOX OF HtBJER AXD RESIXS 21
to H 20 the )olutioll becollles somewhat vbcou5 and precautioll Il1Ult be taken to ttvoid bubble formation When it i5 poured into tilt Cllvettes
It should be lloted that both of these precipitants have an ftellleshymmiddottion It was found that when XHjOH was used in the rubber preshycipitant in pInt of H~~O~ the readings were -table l)Ut were not reshyproJutihk The lIl of XuOH in pInel of H 2SO j ran nHittble result as a llth H(HY(Pl WIWll til( li-P(l put lthatgtl in lublltl llnalysis or H~O illlP-ius anal)j wn-i uddint(1 thl eharalteliti(s of till liquid with pleeipitated ruhber or resiu in HI~P(ll-ioll n ren1 on the lpNmiddottroshyphotometel m tololinlPtprfollop(1 it lPgnlal lIlll II~ lxplaiHd on pHgP-I (Sl( figs 11 aIlIIl) Tid made it lloible to outain lEPJOshydlHibll tpnlt nntI (onplt1J1(Jttly till JpqnitPIl tlPgJPP of PJPcljoll
IIWIE(TI 1lt COl~101J)
Jtl thp ItJiPl middotxlwlillltnb hefoJ thtmiddot -1l]YIlIt allll pnmiddotdpitallb had lIptll ptoppJly adjutp(l it l fOllll tIuH till llP or a Ploltiw colloid -wll ltIi1)cJ [ttlJmiddotntl- imlIopl tll lmiddotpro]lIibility of the lPlllt JmUkllly ()Ilt 111 U lput lUlU illlihumiddot tOJllPOlUtl tpHd liglyeol teltlut( - llpanlItly IllmiddotlfP(] to lit til I1m t IHflll lImnnmiddott nftlr tlH filial prOIptlllll WtlP dlvPllill1 tlll 11lIlpfit (If thtmiddot [llltlltin lollohl wa Hot 0 natlv I1l(lhmiddotd III rlumiddot Ia- of tmiddot ill tllmiddottJmillaritlu it b [1 hmiddotjlmiddot til IIpoundgt Ir llH1 It liltr ill-llImiddottiT Ina lll ptlPII by it U( in ruhhfl mmly j 11If dtmiddottail fOJ tltt lllllmtlllll If thl plot pet in nlloid ~llntill tltlmiddotlImiddotmiddotlttlatiflll lIOlllllllhtiPI1 are iPllllll page
liTFHFEHliG COIOf
(hi II tht lllail 11111111111 that had til ill -111111 II urklll) om tlH method fot lublJtt tlIlO1 rpir- nlalv~i in plaut llllpll- wa ttl (lilll~ inare tIte (gt1[01 till to tIll ptP-PlHt f xi [aIWIIII- 111 TIlt amount of (olor varip from lUllIt tn -amp ]pplwHlI nlt rhmiddot lt IIf thE Hl(ltllial tllP part of till plllIt -lI11lhmiddot(l tilt hi-tlllY f tlll plaut mtteshyrial ~ub-lltInent to Itlllmiddotnmiddot-rill lliI 1011middotly OrllPI Inlw
In ruhlwr lrtl-i I Iii 1101 au Itmiddot 1Iplll11l by 111[ I--r ratmiddottilt thE -lllll]t with uptoIw or 1middotmiddotlIll-ol - wIdell [llllol- rlll loillriu nutttel autI thtmiddot lpill- Thi- howmiddotvt n(tnll- til lXtla -11gt1 ilt prlJ~edun) In lP-ill ltluay-i nllHufldy tlW[t j 11 1 1IO(PIlln fill the 11shylImya of hlulophyll Hwl rIlI-r middotIOII IHlttlmiddotJ dlH lUtl~ In plltIH withoUt alo aiftIriL till nmiddot ulttrll
111 pllIbIll1l Wi tilmiddotr hId h It-ImiddottHI tht Pltlpll 1 hlitlt lilt tlw tulllWlli tollImiddot uIwltllIIntut -lltUIhorlllllltll 1111 tIll tlettlllliIttwr IIf t 111 lWlrl-Uamiddot of bdt tl11blLlittUhmiddot r [1 tItmiddot preshyj
lipitatifll 1lJ llllllWI atbull 1iI- in III -1nrmiddottIi fHlttalldh nlrillU~ amount rf middotlorilig lIUlttll Iii lhll of ih lltmiddottllllhottohttt~l l~ol()r infrtl Hm II upd 1 rwmiddot tld~middottilmiddottll PlllItlhi~ f it j proYitiltl with tIll lilP--UlY tU(jlIdlllIlml tIltmiddotmiddot lllklllUIlI
EIECTIol OF 1 [EGTH~
-Ptfmiddott ral tracilull ru~lI gtIll fr 1 nllb t ~xtltd 1 lIlt-th vI iobmy1 ketommiddot lWtl rill [ Ixt lttltt ll UttollylaIiIitt1l11I1t~ ~-I itoiu YtHil)u~ typp of ~IHaylllt f i lItmiddot art hraquoil ill fio1ll1 ~l Th~ lp-nlt fill I11oohl uio[1t ttl willlr til tltN- fur rht IUiXtIUt iwliutll
100
22 TECHNICAL BULLErIN 920 U S DEP1
90 bull eo
I shyz 70LLI 0 a LLI a 60
LLI 0 50 z
a ENTIRE 2-MONTH-OLD PLANTS~ 40 b ROOTS AND BRANCHES OF ~ 3-TO 4-YEAR-OLD PLANTSen z WITH LEAVES REMOVED ex 30 a C CURRENT-SEASON GROWTH OF l- )-TO 4-YEAR-OLD PLANTS
20 WITH LEAVES REMOVED
d LEAVES FROM 3-TO 4-VEAR-OLD PLANTS
10 A
0
a Cd 100
b bull
10
80
I-Z 70LLI 0 a LLI 60a
LLI 0 50 z ex I shy 40 ~ en z ltI 30 a I shy
20
10 B
o~__~__~__~~--~--~--~--~----~--~--~ bull350 400 450 500 550 600 650 700 750 BOO 850
WAVE LENGTH lM~)
FJGcm O-Sll((middotlllll tramaniW1IHl (mrpS f(JI (xlmll 11011 n J1ll of jlta)nle tissur ill n 2--m1 Y011111P of (A) Illrthyl ji1I1J1ltsl krtonp 1111(1 (ll) nt(middottQnyla(umiddot tClIc-C(l1osuln a-i
bull
bull
bull
RAPID PHOTOlIElRIC DETEH-UXATroX OF ntBHEIl AXD HEstxs 23
ThE dula Pl(S(l1t(lltl indi(ntp Ihut 101 Illp ulimls llHthyl liohutyl htOlIl (lxtrHts (lI(I r(dolls of Il1Hxi11111III nigtol]gttioll wiH1I all (is-lIb 11 cOllsic1(]((l n1( blhn(11 wn ( ItIl( Its lIO to () I1It~ nlid Ii to Iii mJL
WhllNIS tlw I(gions of 1middottnL(s( light 1lnlllittamp al(l lgtPlW(PIl wan Ipllgtltsnr) to Ii nllt jW) 1I1JL nlld alio Silllill1l 111l1b (n SI(lIlId 101 nc(ton ]altmiddot(fmiddotollp-(llloolp ~ pxt Ill of 11a 1111 t illl TIl( (1101 du( to lolo ill tlw litlltitl a 1Il1 lullll(I tH lPill- hanmiddot bpllI PI(_ ipitated ma he 1((I1((d to fltI ynbhing poillt II ph( illg OJ illshylmiddotJall(( WIWp balld nhm ()) IIIJ1bullbull[1I111 lxjlPIitllll1b Illln -h()1 that Ih( lIIot uilahl( WHYI lHlIJ fOI 1-1 ill 1l11J1l(I HIH11Pill- illllllrsi i-in till IlPighl)()lllll()(l of ~llIl1lt bull
bull UIlIilHlIy of n typhn] lXPllillllllt to )10 l1iP(tiP ((JIlllo( of (ItOIS dul to lOIOl in 1llblnI Hnd Iill xtnumiddott 11(11 IIIIolp t jUl i p1llelll((l ill tub]lL Till llhlllt- 1tpIO]II Hnd ((llll~()h whit-h UI(I ](]Hllilltl n 1I01lllIhb1 01(111 lxt 11111 IIll 1llll)1 nmtp[in I and )(middotills Tid IIlnkl it poiblp nftlI tlIp uplll1tillll or tlll o1PIl( (0 [niH lip 1Iidl1p~ of lI111 11111(( ill lit ll11l1)[1 (llnlIb nlld Ihll
Sl(ll n ol1lliOI with tllP olnl IJllt illiollt HIl Iltlllll llllI (Ill ltllthpl prpipitnnt j Ihll1 nddld OUI ha a lIilPt lP( of till lIiciPlw of WH( lllIgth 7) lUI- ill llilllillatiu (nnl till tll Ixtll1I101l ()lll~
Tuu tmiddot-Elilll IJl flrldillY 11-1111 lrlllI IjfJI til islII 1 1(1 ([rllt IIIIIJIlIr JiIlIt~ if 1Il( Ihll 111111 k til I III Ilrln I 1Intd tf 11111 JiSf fill I I II I tIII Ilf Iilltl 1f1JlIIillII1f I Till 1[ 1 IId 1 (I (middotIt 11111 (I1I1iI1 1lf1IWtlfJlIIllfflr p middottrllhIJ11 II J III 7IImiddotIa 111 111 lilt jJIp 111 wilTII
t~t tnVIli~ ~nn r kn t~ i tmiddot ~~l Jr 1middotmt ltlTt
HmiddotOtt ~I~ lin t I ~ 1 t~~l ~qrmiddotthtmiddotrtwb
Hult-middottltlru t T Hw ullut rHtt~ r II I ~ PH~lllt
A~tmiddottHHjmiddott~rjd rl ~gtllh 1 tn~th~ ~ ~ middotI lt~ b w bull hmiddotth~ 1i~lIhun 1 Ii tnl Illd1 -11lt1(11i lullI lUI tJl ll~ t1~11n( I Ihan1li flfttIJir Ult I Uuhtltt ahuul l(hmiddottHmiddot~t trv r fti HIt lftbyl tlonhUt)1 k_hIl( 2 m~ fmiddotf tuhlHmiddotr In mlth~ llmiddotlf- 1 t r
t r_~ t j
Arhlitlltd ~llIIDHl NcWitn1 ( Ar-(lt()nc~middotttrrtrt ritJJI~ -Iu nllJtl4-middotr
ACtmiddottflnp fmiddotxtrn( ~ T-P511ftf tn mtmiddotth~ 1 ~difmiddotut~ kdn 2 nltt ulruhhtr in Un-tIl lltbu )J~IYt
rUth(Hl~hltlft HhubU
Illlh(I(t tttUtUt hUbtl til J ~jlitl(J Hilllll trtIIImiddotjtl1ll
(UShl I ~tlO wHllolH rulh r (middot1111$0]( J~rru t t )lthyl 15bullbull1middot1101 klll1l
Ili( UHUicbcul ~((i1rUtl ~ulu1iin 1middot lIUIll Ilti lrllltlllt I Ruhhr llt1thuI r1 -1 Irld
ltlt1111Sh 2 nuz f)rruhl~rm nlith~l tu- h f nt nil~middothgt(H] tlrlftmiddot 9lUtirtl middot1 1
rlcltfl( H(l dnllltml it
(IISllhH~rI( Iultruhtr CII05 1v ltTlft I 2 UI~r ublwr In llldh I hlt~1 11) lgtjdvr(llsl~9rlltmiddot middotlmin ~ I~ gt AIHItilltl no IrttipHallr iI
~ Bbnk 10ol m(thyl i~tmiddotut~i kdHn H 1 m1 j~~ l1rH-t lt~tlfltmiddotn sf n it ll HltlMjftr~nol O2~mlJ ~U~1o-ulp ti~tW -xtra~middotl(lt1 ltt 411 ml bull ie f Ct- kft rt t~ tirattJ middott ill r u l1kn ttJt
in metltl isobutyl kNqnf nn~i mljp ur tmiddotmiddot ~oml ~urr tttl i t w ltJj1JH kt 4t 3 nlank 1 mL((l1t~rthmiddot(middot mI mttr~ ~but a kmiddot tmiddotc d 11 ~ gtli~b~ hifIAft- fl~ lL lnti 149
ml8(dlfilll BO bull 02 gm guayule U$Stl(middot xUlClt-l tf(h tft wI n nmiddotmiddotmiddotlgt 1 lznt on tmiddot ~Jt r~1 ~~u~~ H~ iI~ thT
24 l$CHNlQAL BULLETlN l20l S DJltJPT OF AGHl(CLlOHJltJ
In table a is pl(sentc(l such c1il((t edlt1tIHC showing that thc (0101 Ixtrnetccl from guaYIIle tisslIe wit h II(P(OIl( n nd (pl1oso[yc is cll(div(ly sCIe(nec1 out by the s(lp(tion or wnw length )0 miL Oil t1w SI)((IOshyphotonwtpl This tnb]p all-HI ihos thai thl Juhlwl altl(l((1 (nn IJl quall shytitntivcly 1(I(()(Ipltl in tIlt PI(ilIH( or Ih (o]OIplnwPIials and Illsins and tlmt Iuhb(l WtlS nppnlllltly 1I0t (xtltI(((1 110111 11l glll1I1l lisslIt b~ tlHSP SOhlllts Thls( ((suIts ginmiddot (OliIHillg (idJt(( that t Iw IISI of waYl llngth i)ll 1Il) OIl till SppdTophot OIllltPI ii t hl 1101(1 p(oshy(ellule in photolllliTie IlIlalysis of luhhlI OJ l(sin-
SELEGTIO- OF )IOiOCUHO)IAIIC ItIIm ((1111110
On th( basis of th( IPHIlb shoWIl in tabl(l 1 al hlllpls (1( IIln(lp to SPCtl lC the PIO]Wl 11101lO(lIOl1ln til Ii ltlJ ((lIllIJi nIl ions 10 llIiOlS (oIOlimet(Is 111(gt 7W-Ill~ filtpl flllnhwd 101 til( I1~lI1l photoshyplpct1i( (o]oriJl1ltll fol which Ill( (hlll(IlIiitit~ oj t hl Ilda he light ilUIlBlIIhiSioll (t) elll nn -hO11 ill fig1lle 10 iws satlsfa(lolY IPshysultl 111( iiO-mL HitlI olllhintioll 101 whkh ttp (middotIatinmiddot light tlnnsmission (ullmiddotis a 1-0 showlI ill figllll (I is -nthdnlto1 hut this is not stnlHlnld NtllipmPlli
Up to fhl PlPHllt lIS(middotflll pound11((1 (ulllbinntions jn lltl iOO-I11L Iunge hayc nol bllll SlClIlld 101 lhp Klpt 1-1I1l1I11PISOIl (olOlinwtll bu fnltlwl nttCl1lpti 1( )(illg IlIHd
TJIpound OF ST~lmW AFTEH HIIJ1EII Oil HHSIS rlll~CIIITTI(J
~ considl1ltiol1 of ttp lillll of Inlllling af((1 plpeipital ion of 111gt)(1
01 l(sinSTlOIll ollltionis impoltant J(jl~ thC1HI(Plltngp of light IInIlSshy
11 rshy10 f shy
09 f shy ~750 Mil- DOMINANTI
~ 08 cshy I WAVE LENGTH z
I III III i O7 - I III
~06 - 05 shyw
a
Igti= 04 - 720 Mp DOMINANT ct WAVE LENGTH- ~ 03shy
02 f shy
01 t shy 1)O~~~gt~- J 600 700 800 900
WAVE LENGTH (Mp
bull
bull
bullFIGlRt IO- COJllPIUlItiw ~IW(middottltll tlnIlRlllii-lion (II (IllP( 101 1i11(1 olllhinulloll
with dominllnl Il(lllllgths at 720 and 7iO lUi
bull
bull
bull
HAPlD PHQTQlfE1IUC JjETER~lINATION OF Rnmrm AND HEtiINi 25
mitted (spertrophotoll1eleL lCuding-) Ol light (1 (tClcrl (phOlOshyJluol01l1et(L lcndillg~) i~ StlhjNl to (hangl
]fjt~l1le 11 and l~ show that ill til( (asc ot tJaugtIllitteltllight llJHC th~ (x[llliHlllIlnl (oIHlitiOllS tllpl j lilst n dtlln-e ill Pll~(lltngl or UllllslllittnlH( follrnY(l by It ptJiml of lClntin stability with only sliuht (1111 tHn- a f(Pl a lIt1ll1btJ of minutes The light t UIllllitblllll t l(1 ill(Iln~(s This lIIay IJP llllllJltlli7P(ll1 ffl II ow 1Ilt )( f(( darI oliIII tIIlIlNlIlitt(IIIlfJIIlh (iditilIiid Ilil1 pllIipintnl )uoshyIn Of ( 8inx in (~f1( I~iUII i~ Ild stahl I 11 itlll If 1inl nh prlshyilli(ioll of 11l1d(1 II IJIX f) jllIli II (fJJltfiIIlilty slllMI IIriot 1) IIIPldUnl1i tll(I1I rllltltilJl oj tJi~ Jlt jiot IUN ilUf Jxl1 will tIt( tOWI IItlllilil I 1llIlllblJIol I ill I~11l11111 d ill till ifjuids JjOI scnttplltl light 011 till phololltHJIOIl1lttl till dilPCt ion 01 elangl b tlw IPrfIi (If that illrli(atPll rOl tlulll1Jittp(lliuht It Itlll b( llluliJr I-(Pll that if l(middotndlnJ- IIIP mad n itl I t lIP ~()ll1d()lb lpalll this pllioJ of nmiddotlatirp tuigtility tllP llLot tIOllt thi Olll(P (nil bl IPdUCld to tIl lltini III 11 Ill TIll l~adiltg (illH~ bbll Oil tlHl datn rUl lublwls and llsinlt Illl ginll ill tnhh
50 r----------------------------------------------- f shyZ
~ 40 ~----~W~A~V~E~LE~N~G~T~H~7~5~0~M~P~~~~ ~ --------------------=-=-= ~ 30 f- WAVE LENGTH 540 M~ _z _____ ___ -=- __ _ ~ ------shyt ~_=---=-=--I GUAYULEIII 20 -Z HEVEA ltt II KOK-SAGHYZ f shy
4 6 8 10 12 14 (6 18 20 22 24 26 28 30 STANDING TIME (MINUTES)
FIlirtn 11 Emmiddot of wav hll~rh Il li~ltr tlall~lIIit1alHl aftI IUIlItHt -Imlli lug 111m for guaynh llmiddotn 011111 middotiolIlJh~z 1111111 llijlitul1 flolll 1lHlh~ll1Jllryl k11II11l ~(lilltlll h~ lwitlitll 111Inu1 111l~1It1 2)1111 o1U11111 (Helillins on (illllun tlunhll IlIIJlllw]ntllW111 lutl(I[lholtllllltlt with ijUjt Wlnl IHI Ilf1 I
11 EFFEGT OF Hbli 1 -()JXT10~
Tilt lnblwl ~()h(llh pxtnl( till IPillgt ubo It 1m nllu1- bellt -~atea thut ~lll 11-111- tUP olnbhmiddot ill middottIIlIlOl ~1It tlWIIJI( my U)t PIl (tlIHatcl WIth tl1l lullh(t I tahle lJ 1hln 1- -1111 tIll (llllstlOll of nny p()~iblt tITptt of XtIIl11 diflp]lws ill ((JlllPllttUliollS of 1l-in lil lolutioll alollJ with till 1lIltbpl TIU data ill wbh +ho on tIl( hn~is of (olorilllPill ladillU thaI tll( IIUOIl1t of lnbbll Plllipirntld 110111 Ilwthyl olnlld kptOlll olntioll IJ 1li-jHlllnt 1l)04 in 1-llltlIllt ethallol)- not amlll hy thl llllNlI(l of llvin aU1ouut of llins inolution bull
-----
26 rECHNICAL BULLEfiN 920 U S DEPl OF AGRICULlUHE
100
90
80(I) C)
z Ci 70 UI a 0 60 a ~ UI ~ 500 ~ 0 I Il 40
30
A 20
0
100
90
(I) 80 C)
z Ci 70 UI a 0
60a ~ UI E 0 50 ~ 0 I Il
4-0
30
B 20
0
--
--shy ---shy---
2 4 6 6 10 12 14 16
---shy= ~ ~ shy
-
2
025 05
10
15
20
25 -30
35 40
SO
-60
=70 80
16 20 2224 26 26 30
OS
- 10
IS
20
2S
30
35 40
-50
-60 -70 -80
bull MGPE 25-ML
VOLUME
bull
MGPER 25-ML VOLUME
Florm 12-EtTld (If till1l or Slllldill~ 011 light transmittallce (01 (A) gUllyulc lnUIl(I plccipitllitd frOIll llltt h~l isobutyl Ielollt solution Ily neidilic(l ethanul bull null (B) gUllyule ll~illii pre(ipitated flom aeltoll~lllcetOlll-Cl])osolY( 3-7 solushy11011 by H(illilip(i l1U (HPlldillg~ nt -lIlillult Ifllpluls 011 Evelyn photoelectric colorimellr with jU-lllp tlllll alit U-1I11 npN(lle spp also table 2)
bull
bull
RAPID PI-IOlOMEllUC DElEnMINAlION OF RUBBER AND RESINS 27
TADIbullbull ] 4-ReZation of amiddotmount of middottbber pleeipitate(Z Oln metltlIL isobutyl ketone 80lutions by OS-pereent H 2SO in 95-pere(lIIt ethanol to umollnt of resin8 udde(l U8 indivute(Z by colorimetrio readinU8
(Rubber ami resins cnlculntcd on bnsis of amounts in 5middotml ullquuts of extract from 02 gm of tissue in a 2fllll olumo( bull
Hubucl r~cocrell whcll rcsins nddcd as IndIcated Htbbor al1dcd (pllcollt) ---shy
__________bull_________ ~_12rpcrc~15011crccllt 7511crccnt IOOpcrcent
PerCtllt ercellt Percellt Percellt Percent o o o o o) 50 250 263 252 25000 500 500 500 500 700 750 750 751 749
1200 1250 1250 1250 1250
EXTRACTION TEMPEHATURE AND TIME
Typical experiments to detllmine the time required to secure maxishymum extmction of rubber und ltsills at 115deg U Ilre sUlIlmarized in figule 13 the solvents used-methyl isobutyl ketone for rubber anrl Ilcetonylacetone-cellosolve 3-7 for resins extraction-are very eflicicnt since under the conditions indicttted maximum values were secured after 30 minutes of ext1llction The most eflicient liquid for the bath (lig 1) used in extrtlcting rubber or resins is ~ high-grade cylinder oil (S A E ~O) The sand bath and such liquids as glycerol have proved unsatisfactory
RUBBER AND RESINS STANDARDS
According to the National BULeau of Standards 1-_ lhclc Is no gellcrnlly recoglllz(d standard lIIutcrlul [ior II rubber standard] The rubber hydroCllrbon ill llifferent samples of conmlcrciul smoked sheet or pale crepe from heclI pluntlltions nries from l~ 10 04 llercent of the totul nutletmiddot the most 11Ioruble conditions Of preparation
McPherson () has described a procedure for the pLeparation of pure heve~ (Hevea brasiliensis (H B K) MueH Arg) rubber from crude rubber or latex In the absence howevcr of ~ generally recogshyn12ed stalldard for rubber hydlQcllrbon [caoutchouc (CnHUs) xJ the standard adopted was that of the relnthely pure product secured from gunyule tissue txtractiotl nccording to the Spence-CaldweU method (5) or the motlified PIOCCdUlU of Hohnes lind Haasis (p 2) The details for constructing the calibration CULes are given on page 10 Standard rubber samples apparenl-]y can be stored for a long timc under the conditions des(libed on page 10 The duplicate colorimetric lendings for glULyule rubber newly extracted by the modified SpenceshyCaldwell method were ()J2 ench as compared with US) each for the sample extracted by the same method but stored 1 years In each case colorimeter rcadinllS were made on mixtures containing 2 mg of rubber in It 25-1111 Yolume
The selection of tt suitable standurd for guayule resins presents some dilliculties Tll(~ acetone extract of gUllyult estimated on (l gravishymetric busis~ for instance proved to be variable depending on the type of tissue sampled or season of sumpling because such fractions as
COllllllunlcntion dul(lt1 Octohtr 22 11H3
28 QECHNICAL BULLEQIN 920 U S DEPT OF AGRICTTIIlURE
16~==========================115 shy
14 bulli= 13 z ~ 12
ffi II Q
10 c w 9a w
8gto () 7w a
6a w
5en III ) 4 a
3
2
A 00 5 10 20 30 60 90
14~------------------------------------------- bull13
i= 12 z w II ()
a 10 w Q
9 c w 8 a w 7gt o () 6 w a 5 If)
z 4 If)
w 3 a
2
o+B~~__~__~____________~__________~ 5 10 20 30 60 90
HEATING TIME (111 NUTES)
lllGUltE 13-lDffect of time o( lICntillg O2-gm samples of gunynle tissue with solYlIt nt llfio C on lo(OVl)ry of lllhlJer alld 1Isim Lt HlIhblL extracted with methyl isohntyllwtone B resins Cxtll1cted with aCftonyla(etonc-cellosolve 3-7 bull
chlorophyll are weighed along with the resins in the acetone extruct but are not estimated by the present photometric method (fig 0) 1he use of a diffeJent stanclttrd waS therefore indicated
bull
bull
bull
RAPID PHOTOMETRIC DETERMINATION OF HUBBIm AND HESINS 29
The resins standard selected is based on n relatively pure source of resins the rcsinous exudnte 011 the stems of guuyule plants IJldimishynary expeliments with the resi nouS cxuclate from diffcrellt gllayu Ie strains of various ages indicatc nHlt there is little YaLiation in this subshystance on the basis of Colorimct(r readings 011 2-mg aliqllots of 01shypercent solution in It 2i-ml volume (tabl( li) Expelilll(lnts have shown that the air-dried (xuclate contains 3RtOH p(Ic(nt of -volatile matter This material is l(latiyt~ly stablp ill (OlllpoBition and is npshypurpntly on ly slight ly hygroBcopic as shoWIl ill Ia bl(1 1 Tlrp Ipsinolls exudate may be jJleplpd in two wayi-i fl liSP as a stallClHld-(l) the clpan exudate is clripd iol Ghouls at ()1deg C at W indlPs of a(lIum Hnd aftclbCinOglOund ill a molfalis 1)I(spI((I intn airtight COllilinel OL
(2) tllP Cx7lclate is clissolllt1 ill a(lhllll and filtplpd PlactieaJlyall of the acetm1l is thpn lYapolntwl olt OPI a stlam or atCt hath and Ow residue is dripd ground an(( PI(sPIld as ill tllp fin lllethocl Tlwse two prepalHtlolls a1( (ompalpd in ta hlp ) 111( (((tails fOl ~t()lil1g the resins standald and (onstlllcting the calibration CUITPS alc given Oil page ]2
lAIIIg fi-CUIIIllrsoi (lJ lIr-dr(1I IIIIi 1((11 II II-()I-tr((l l(sil~ 11111111(8 of I II 1111Ie
[Colorimetric rrndill~s 011 1~I11 phulll(Iclrie eolorillJct[lr with i~()middotmll (100- to iiOIIIIl) fillcr [lnd 5-1111 lIperture preeipitantl part ofO5middotPIrctllt 10 to 5 paris of IIOj
nupliclllc(oloritwt([
nIl(lin~s (hIlSlcAg~ ofSlmillXo JrNliltlCllt of fPsiJI$ L1Xtlrlntp on 2 IIIg ofplanls fllsins (XIHIIlt~Jwr 25-1111 vol
tII1(1) 1
leflTs Various _ bull ____ bullbullbullbull 3-9 Colll)Josiltrlairmiddotltlricfl bullbullbull nf)2 002
])0____ bullbullbull _bull __ _ bullbull ~-l Composilld (ri d at n5 C in aUmiddotimh lWUUllJ for l (jOuj(ja hours])0______ bullbullbull __ bull ___ bull 3-0 COJIlpositld disso]NI in neptolll f1l1erNl fl(lf()ll( GGO i(jO (Ivaporntld olT OV(1r Stpl1l11 halh TesidlH drl(ld I1t fi5deg ( ill anmiddotinch VIl(Unlll for 0 houlS bull
middot106 __ bullbull _ Jir~c1rild_~_~_ _~_ ~_~ _ ~ ____ _ __ _ OUu GOifina_~ ~ _ ~~_~ ___ _ _fln~ ~~ ~ ___ ~ __ 6(imiddotI tiliA H)[_ ltlu bullbull i18 tisSflOabullbullbullbull__ bullbullbullbullbullbullbullbull lt10bullbullbull _ tillO llitO406__ bullbull __ bullbull __ bull __ __ lt10_ Utl2 fon591_ fo__ bull liGa oOa 406bullbull _ __ lt10bullbullbull_ li5S OM
j Ph( vnluls in Uw Inst COIUIIlIl indieatp thnt gunyulp fesinous (IIHlnt( wlwtlwr dfircl hi Yn(tlLJ1l1 wilh L~ perc(nt loss of volntllt wutl pr or tWl c1rild giVPd npproxil1lnh1ly t Iw snllw colorinwtCr rNHiing- 011 till busis of aliquot~ cOlllniuiug 2 IJI~ of flsillS lXIHlntp l)tIf 25-mI volultl( Ihil- illdicate~ thl11 Uw UITW IJ1flS~ of olnshytile mntl(f prt~(iJlitnt(d gins npproxilllntlly Uw $1II1l (oiOfirnl1tlf ftudiTlJs ns tho ftsidtw A pnlill1jllaf~middot (XIlltrinllnt indicutls thlli th VUllltill muller l(lIlSists of thl Ilrplne oil fmcl ion I5-(1Il gtnplls or rlsitlOtlS (lxudntll gnvll by stPll1U distillation nn Uefllgl of 011111 of jl(lfPlIW oil with npproximHte tilllsity (If OHIi lind lhus rrprlsll1ll( IlPIJroximllt(I~ 01 Jerccllt Of t he original weight 1hls lllrClnlage complrcs wllh 38 llltrC(ntlost by drvinI( in IICllnllJ
aSplusmnUH perceilt or orlginlll weightlosl
The wailnble illfolJllntioll on tlH (ow-JitlPllts of the gunYllle r(~shyillOllS exudate alld tl1( HeetOlIP ext act of gaylp ti~slw is sllIllmarized in this paragraph lYalttI (u) alld also Hangcn-Slllit lind his coworkshyers 16 reported that 20 percent of the resinolls exudate from gUltyulc stems is parthenyl cinnamaie (CHuOH=CHC020 11JI2r) Steam disshy
15 (OIlIJIIIIUicatioll flom A T Haai(II~l11it llId (0011(11 Calif0111 ill Tnfiitnte of Tccllllology Past(IlIJI Jhps( wOlken al Htud~ing the COTlHlitlllllts of the acetone extract and other conlltituellis of guuyule
30 TECHNICAL BULLETIN 920 U S DEPT OF AGRICULTURE
tillation of similar resinous exudate in the writers laborntory has yielded approximately 4 percent of the whole as the telmiddotpene oir fracshytion Haagen-Smit and his eoorktrs nportec1 thttt about 25 percent of the acetone extract from guayule branches is parthenyl cinnamate and 6 percent of the bark (ltortpamp-phlotm) extraet is parthenyl cinshynamate These workers fm-thcI reported that 25 lwletnt of the nc(shytone extract frolll bLllllches is a compound with the tlI1pilicaL formula CBoH400a 1 percent is a compound llwltillg at 2P to 2T5deg C and 1 percent of the extract from the ]eav(s is tl (olllpoulld nwlting at 100
to 1710 1Valtei (6) reported that 3 to -l perc(nt of the tI(eton( txtract
of leaves and flowering StPIllS of guayulc eonsists of waxlike substances soluble in olgallic soln~nts but insoluble in at(l and (on(ent1llted H 2S04 The flactions mentioned on the basis of (onHLTutle esti shymates of amoullts actually isolated tlecoullted for about H ptIcent of the totalncetollt~ so]ubles extracttd from tll( guuYllle 11 rub The other constituents ltlilaill to be i(](ntifi(d
RUBBER AND RESINS CALIBHATION CVHES
Typical culibndioll Clllves iol Iuhbpl and I(sins bas(d 011 (ldtLminttshytions made nccoLdillg to the plocCdmC outlin(d 011 pages middotb to 1G arc shown in figulPS 5 and 1+ The spCdlopliotoll1lttL en (OIOIjlllctCI readings are plottCd on s(lIlilogalitllllliC pappi ag-ail1st (Il 11IbblI (011shy
100 ~ 90
80 ~ 70 ~
z 1amp1 0 II 1amp1 IL
1amp1 0 Z
60
50
40 ~ltI 30 ~ en z ~ ltI II ~ 20 C) ~ oJ
10 o 2 3 4 5 6 7 8 9 10
RU8BER IN 25-ML VOLUME (MG)
bull
bull
bull FI(lURE 14--Ctlihration curve fotmiddot gllftYlIlc lubb01 (Hct(lings Oil COIPIIHlII tlOl1hl(
monochromator SlCClrophotolllet(r with 7fiO-11IL Illtel alld Hllp Wll ( IHlll()
bull
bull
bull
RAPID PHOTOMETRIC DETE~MINATION OF RUBBER AND RESINS 3]
centrations From a casual inspection of these CUlTes it would appeltr that Beers law does not hold Actual tests indicitted that Beers law was applicable only within a narrow range in the upper portion of the curves The analyticlil results on the basis of photornetric readings nre therefore calculated by direct reference to calibration curves or from reference tables of equivalent values bllscd on the cnlibllltion curves
Calibration curves for kok-saghyz alld heyea lI11tulltl rubbers and Buna S (GR-S Chem Gum IV Goodyear) and butyl (GR-I Standshyard Oil Co Protoc) sYJlthetic rubbers are hOWllil1 figure 15 The samples of kok-saghyz rubber were furnished by the Diyision of Rubshy
100
90 ~I) ()
z 0
1amp1 a
~ a
80
70
60
s 1amp1 ~ ~ 0 ~ KOj-SAGHYZ 0 l Il
50
HEVEA~ ~
40
100
90
~ 0 80z Q 70a Co)
a 60 ~ 0 0 x 50Il
40 ~----~~----~------~------~------~--~ o 2 3 4 5
RUBBER IN 25-ML VOLUME(MG)
FmUIlE 15-CaJiblation curves fOl kok-snghyz h(YCII Bunn S lind butyl rubb~ls (Readings on gy((yn photoelectric colorimeter with i20-lIIp filtpl and 6-ml aperture)
32 TECHNICAl BUIJLETIN [)20) 1 S DEP1 OF AGrnCUIlfURE
Iwt Plant JIl(I~t ignlioll of thi BlII(un and (1( l))(parcd according to 11( SPltI1((-Culd (]] (6) PIO(((lllll Hlpt pal( CLPPe was (xtmch(L with acetone blI()Ieit W 1I(gt(11l a ttnlldal(l
SEXSlllVllY Ol~ llETJIonS
By lip pIO((l(II11P olltlillP(l 011 ]Hlg( +n Iowa (lOOl IIIg (11 1111i(l0shygmm (gHlllllla) of 1hblI ill a 2)1111 yoltll1ll (all )(gt dltpltld Oil tltl Col(man (lohlP mOIlWhlOl1lHlOl l-I)((t 101 l1lOt 0111 ci( I ill1ilnlly 001 mg of Iublwr ill a 2J-1ll1 n]ulllP Illay bl Ilad Oil till EnI)1I photoshyllectlie (O]oLillllt(I Thll ya lllll- 011 tilt IHl-i- (J I (xl ad iOI1 fmlll 02 gill of til-lI tH(JI(lillg to tllP -lllndal(l jll()(pdull 1(PIPStlIt IlO()2J tlnd 002) P(IT(lIt of llIbl1ll IPI)(((inly bull1t1lollgh -lI1t low allils can be d((d(middot(1 il lIoullt1 Ill IPtllizpd thnt till PIIOl ill PlI(Plltng( or tll( al110unt dltlIllIilll(J i ltlatlpl high ill tili PIY lo Itlllgl 111 aetllllllladie(middot Ill( lopl lillliL 111)(1(1 lIw (ollllil ions of tlil ]lI()(lltlIIIl u ol1tlinpd ipt at l11 11I1 or 1111gt11(1 illt i-1ll1 Ollllll IlPIPltPlltillg 01 p(gtl(pnt of JllUiJtL un tlll 1Hli or (xlla ion rlOI11 II rlll of tisSIll
EIlIlOH COSIIlIHIIO
In Oldpl to H(IIp ill )1lHtPltt pl((iioll illlpIi1I- it i lH((SSHI to slnlldHIdiz(i rigidly 111( Pl()((dlll( 0 illdi(ntpd Oil pnglt- - to J( If lids i dOlH tlip lXIHlinwnlal PIIll is t(middotdllld 10 n ndninlllill
Illlt pl(iioll of (hI ]lIPPllt 1IHllwd Oil til basi of ]llllP llIllJt1 alld Ipsinssollltions call hI jlldgl(J 110111 figllll Hi lileh lio- til HPIlIgl d(intioll oft -illgIP lI1lnSIlIlIIIlnt in lHi((lltagl of Ill( alllOllllt 01 Illhshy1)() 01 lpsins d((PI1I1 iJlld TIl( (1101 PlI(Plltaglt H1( gi (1 101 OJ) to
RUBBER IN 25-ML VOLUMEMG) 004 01 02 03 04
i= I I IZCtOW
fbA ICtU CtCt WW a
01 02 03 04 05 06 07 08 09 100 = RUBBER (PERCENT)
RUBBER IN 25-ML VOLUME (MG) 10 20 30
~ I CtZ
bBOw Ctu CtCt Ww o I~
010 50 100 150 200 250 RUBBER (PERCENT)
RESINS IN 25-ML VOLUME(MG) 10__ __3-0_ 40 50 60 70 60 90 100--_-- 2_-0
Ct~ -r- 1 I OZ
WCt UCt b C wCtW
a o I I 150 250
RESINS (PERCENT) o 10 50 100 200
bllI 1tI W-Yllnl dtd1 ioll I I 11l1 11IlI11 1(111(11 1 III Plll- IlIIIlol1 01 IIim~
bull
bull
bull solution Il basis J o golH of tiSSII (JlILCl-nt (11(11) for (~I) (l)1 til O 1I1
of luhllpl lin 1 III I (I Ill of lUhlJPl nllll laquo I J to 111 nlg of IlSlllgt (Itllillgs on ]iYllyu pllolwh-llrk CO[IJlilll(-(PI with nOHIP Iiltlr lIntl U-lIll allcrture)
RAPID PHOTOlJElRIC DELEHlllNAllON Cn HUBBER AND H1~SINS 33
10 mg of rubber anel1 to 10 mg of resins in a gJ-m1 yolumC For
bull
bull
bull
comparative ptuposes the leslllts arc also calculated on the basis oJvershycentage rubber OL tltsills in 02 gllI of tissul As WOlllL be expcet(d the error increases sOIlHgthlf for 1(lali nmiddotly low COlHell t1llf iOlls oj rllbbeL or resins The curves in figure 1(j s1l0 that ill til(gt Illlge Ol to 10 pCrshyeent of lubber the elTOI rangts Jroll1 abollt Ll to II) ]IlC(lIt abo(~ this mlllc tIlt (ITOl d(((ts(s to (ollsidlItbly ltmiddotss (han 1 1lICPllt of tlH mllollnt ltl((Lmill(d Hil1lilally in tlH (lISl of l(sins analysis (fig 10) the ltLTor is (onsit1eIubly INS than 1 PlLllnt ill (he lallgp of 11 t~) ~() penPII t
In nil ([lSl of lllhblI alld (sins lx(Inltpd tIOIl1 (issups Ol addcltl to tisslle lxtlads (s(( tabhmiddots (i H) illyolillg ll01P o(lllntiolls the eLI01
is hig]wl thun that indilHtld in figllll ((j Im pUIl Ill )])p I tllllllsins solutlOII
COlllUCIIOXFOH IXSOLl-IlLl~ Ilgsqgt(Jg
111 th( Jllo(pdulP ollllillPd 011 paw I till illsolllhll isSII Ipidll( tflpl (xttlw(ioll is (Ptill tlw lIask l(lll till xtlct i l1wdp up to yoltlllH It is not rOllPllipnt (0 IPt()PI qWlIltitati(Ir III(lw[olH a 11(1 pllooll extlnlfs of guuyull I is-lll alll thl1l main t11l111 up (0 YOIUllllmiddot bpCaUHI sllch all additiollal stltp wottld]) tillll-C(JllS11ll1illg Th( Iogiea nll(gtIshynntin is to mnkp tltl lXtlUCt Llld Ipsidup lip to OllillH in till original flask andi llPSStllY 10 llwlno tl OIIpdioll wlHIl (allIlnting [hc llshy
Hults f(JI [hl oll111lC displupd hy till ins()lllbh llsidll( III it l)picat (IXpednHllt (ollsisting of Jhp lppJiea(iolls if was Iollnd llftt at ~iiO ( 02 gill 01 Iuhhll pillS IPill-fl(( lisslI(gt (lollpdll fot llwistUlC ou basis of dlyillp ut lOW 101 ) llOlll-j (lbp(ld only t~ llllUll voiul11P of OOk7D~- OO(lOO(i Ill of lllthyl bolnl(yl 1lIOll( (lplhlli(al-t(Tnltle sp gl () Ii I ll(Hli (j at ~)) -gtitllP tl1(gt 1It101111( () r t is-lIl xt Iadld j sl1lall til( PlIOI dul to Ill(gt insoll1blp Ip~idll is slllall III [0111 ill( wOtk it (all lJp diIpgal(ll(l
]hcon~lIY OF HllIllgl AiO HESIS AIH)gl) TO EXTlIACI OP
GlYlLE TISSlg
Tnl)ll G L(IHpslntillp (ypi(nl llld(~ SllOS (hat all a plngl of HIOK PlI((nt ot lltl pltl( Ilhl)(l acldpd to tllP Itll h iolJut1 InmiddottcJllP xhnet
of guayulp tiSI1( WllS 1l((PllIl Tlli nllintioll flOlll (olllplpU I((OYshy
PIY i within flll pxp(IiIlHuttllIIOI ~illli]llly fnbll Ii llows thn 1111 llYlIUgl of 1O(1~ ])(I(Pllt of gllllYllII 1(-i1l- add(d to II( (pllosol( (xshytrae of IUllY]l t i~HI Is 1l(oPIPI
THl~ (~ Hf (Off Ill of 1111)( J OJ I~il~ lItfI(( In ~(JI1IJk~ Ilf (111 [lI1Il fI2 lIII
0 tlUfllllit i~~I1
Instrument
---- ----~---- bull shy 1(1
Colemun ruono~ltrOUlllt()r 2t) II sJl~ctroJlhOL()lIIeter with 2tJ I iflllllI wnclength Fetting 21 II nntl 0-1111 WU HI hUJl(L _ L U
Ill 7Evolyn photo~lcclrie (olor JU [ imctcr with iO-llIl filler IV (I
H1 0 t I I
llImiddot lUn WII 1011 HIO Wn mil lUulon
10 JIg1111 IUI ml lUl anh Io aLn 111)_I ) III li lU It 2) deg wn2SU DD
Irl JIll II IIr II US II
1110(1 lULa lUI IlK) IJ WU
I( llI Htl tNI 1(111 2tlNI HI 0 221) lllil t2S 0 1~ 10 1~13
In (I 2117 I
10U 1l(J ~ 4 _H_j ___
9middotJIlJ5 10115 10 00 lUU5 flUU 4li (tl03 9(11)
leIlKl 1l~)5 lOOU l1KIr JOIS un 003 OIl Ii
34 lECHNlCAL BULLErIN 920 U S DEPT OF AGRICULlURE
COMPARISON OF PHOTOMETRIC A1D MODJIoIED SPENCE-CALDWfLL METHODS OF RUBBER ANALYSIS
Guayule samples were analyzed by the photQ111etIic method and by bull the modified Spenc(gt-Cnldwell mcthod The values in table 7 represhyselltativ(I of typical results indieate It -atisfactory dcglpe of conformshyjty between the two methods in thl range of tiSSlHH with llHHC than OJ) percent of rubbtImiddot On the bnsis of the amounts determimd the results in this runge for the plmiddotts(nt lIlcthod ayernge apploxinHltely j percent highcr
~LAIII~ 7-(oIllJl(i~on of lltlllrIic (IIri mOtllinl SJl(II(r-(ulri-wall IIIrtlwrl~ of rlrrlIIillillfl 11)1)(1 COIIrll of UI(III
1 Flowers frllm amiddotmonth-oltl nursery plants
YAIIIATJO- OF SIli(LE DETEnt1NATIONS Fnoll TnEIIllIEAN
Rllbbel (Uall8i8-Thc plcCision of thc pLcsent method when gunyule tissues Hr( nnnlyz((1 for rubber may be j udg(d flom I Ill datil presentcd in table H TIl(se dahl -how that thl pplCPlltag( uriation of single determinatiom from nwan yullles with low standllrd enolS ranges from less than 1 to 4 p(gtrlent
R(8in~ wWlsi-r-s lndi(a((1 011 page ~j he INntlts s((uled hy the present phoolllttric nsins llHt hod are not tliltly (olllpalable with those of the grtLVimetri( ncetol1l-cxtlt1(tioll II1etho(l Thjs made it necesSllry to selc(t another lalibllltion staudud-tlll Ipsinous exullate from gullyule shrub-thut gies relatively COllstlllt photometric readshyings (table 5) The resin (olltents of guayule roots branchcs or leavcs usually ran(~e from about) to 1-1middot pelcellt The ple(ision of the present methotf WhCll gUHyule thslllS lIe analyzed for reins may be judged from the datalHmiddotpscllted ill table 9 1h(se data show that the p(lcelltage variatiun of sillgle lhmiddott(Lminntions iLO11 meun ynlnes with low standard NTOrs rangcs from about 05 to 4 percent
bull
bull
bull
bull
bull
RAPID PHOTOMETHIC DElEruIINAlION OJ RUBBEH AND HESINS 35
IAIILE 8-luriation inclieute rubller (mallSM of [1wIIle tissue bll thc 1111O0Illclc metwII
Vnrlntlon~Ilbher I (rom mean
ierCtnl Percelll ~OU -22 ~ 25 +27 ~ 20 +18 ~UO -22---------1_______ 51110 0G6 bullbullbullbullbullbull _bullbull
10 ro ----=ii41075 -01 1000 +11 1010 +13
rlln HI itil 1l9~ 1_ ___ =-~~~
115511 ~ US -111 III II 1575 -13 115 b tiS -I a 111 h WlU +22IIM-(middot bull 11K -1Ja Illi c 1000 +03 1J5H1 W +l)7 ll1imiddot tl 1575 -13
Mcnn 15951 131
1102-11 21fJ() +21l102-h _ ~~)SO -17 1102-c bullbull 21CO +21n02middotd ~OIiO -26
2 r~plusmn Il~ 21151 261 I -~-------bull---__ _~~_~______l-___--_
1 lhe$ 1111($ I1n (or SlIlIIllltS Stpnnltplr PHrilClld IIrtlrdlng 10 1hr prollIlIlr( OIiIIiIl(o(I on Imgt$ 4 to IC ~tcond nUlI1 hlr r(J)[ltnts stl1ndnnl llrrot of tilt 1I1(1111
1_1l1~ n-J(lri(iot in relli(Upound rpoundsins (lllalIsfs of VIOJII( lixsue b1 the lhomillric lII(lloli
-- ---~--- - __-------- shybull I I I I Varlgttton
_________~___ ~~lu_n_Jl_Q_~~~_____ ______I__~_o~S_J frOID lDean
Percent Percentgt458-1 ~65 +41IWtl-li 130 -a2Hli8c aliO +26S41i8-d bull 130 -32
1(-011 34I10Olifgt __ bullbull __ ~--====
li-9~2n 881) -06 li-9~2-b Si5 o ~HH2middot(middot S i5 -6$-H2middotd 000 +1
8851 054
O i5 +6 9 i5 +6 950 -20 U75 +6
H-liG3o-n bull -1 n-li6~b bull __ _ -IH-IWH +4H-l61511 bull -1
1tmiddottlU
62~-lI __ 62~-b ij24-( bull OH-Ji
(-Ull
I rll(St oluls nre tor separately ~xlrflCled SllllllllCS IlctOrdlug lO procedure outllned ou pages 4 to 10 i Secoud number r~prtgeulS stulldMd error of lIe menn
36 TECHNICAL BULLETIN 920 t ~ DEPT OF A(]RICCLTCRE
ReUUER A~ALYSrS I~ CRCOE-RcuUER PROOCCTS
Sew rapid photometric m(lthod~fol the ddellllinttion of rubber and reii Hi ill uaYllp ti--ut htp lllell pIPHnl pd oil pag( ~l to In A brief H1111111tlY of It similar rnpid llHthod fm 1I1hb~rllnltlysis of u1lulcanizNl tlIldp lubbll pl(Hlmtlt whielt i~ bn-(tldo on the prill o
ciples dehtilcd tlllLe follows Duplltate nt-gm sllmph of the finely cliyiliNl IlInttlitiup wlirllll out [~ei-()l (all hl lIf((tinmiddotjv INd to lt1iyidl till alllpl) TIll kltolll-olubll portion of till )111(11( tlrc di-olved a- indh-Htpd fot thmiddot lllnkill~ of -tlllHlunlluhhll olutiou Oil Pt 1II hut tIl IUlIp Hn lIn l-fplImiddotd 10 lHI-ml rolllllltti( fln-k antil1ltld(lup to Olllll1l The bnlulUp or till JllO(ldllll i- thatutlilllll on paWs -1- 1 IHI Ii 111( 1(111 1- nIP IXPIP--pd nil til IHi or Iw oligiJla w(lullt of I Ill (I11l1p-I1l11Ilt1 1)(0(11(1
Hupitl PlllimiPJojgtiWllllllllh llIltllOd~ fOJ Ihl llPtlmiddotminntion of ImiddotUlJbll tlnd 1(-illo- ill -111111 Illllph of gutlYllll tiUl IIll dl-eli)ed 111() IlltlY d~o Ill nltlI1lld fOl III Iwl Illhlwl- and l~iJlmiddotb(lLiJlg plant TIllt l[Olllhup hns nlo b(l1l ntuptpl fot IIH lltlIll1illtltioll of lllhbpl ill 11lHhrublwl Pl(Jdlld~ HIIl 1111 hI ndaptld JoJ IIll ann lysis of ynt1J(gt( ic lllbbl[- The llllthmb HIP 1gtn(11 fill tIll fol1owill plimiph- III Grinding
tIll PIOPlly driPl t i~lIl 01 Ul tillg tIll pnHhHt to tll l((lllilllllh~lel of filWlH-- til plllllit qIHlIllilnth( lXIIHtioll 01 IIlbhlI 01 1(--IJl- () llsing oXWllutld olnuh (kttoJls IIt(talp and() fllltil for LIbbel and IH(ltIlIlyptIJllIllIoolYlnJld-o flJllh 101 niJlsl with t(lathelr high IlPililig points 111 to n C) l]olle or in mixt tIll thllt Pll mit tlll rnphllxututioll of luhll(l OJ [middot(ill ill ~() to (l mi1lutp It r(latiwly high 1lllIllllltlltP Ill to 1~11 ) l) lllllipitntillu till luhblI OL Imiddot(ill frolll aliquot () f till oltn ion I IlIlllI-i () f Hlltabhmiddot pl(~(i]litallt (willifhmiddotd lthmwl fOl IIlhlHI Hild llitlifild lllr fOJ JP-illl t~) IIlHkillphotollllliilPIIIIiIlof PlllPlltal of liht tLaIlS mittUl(P lIftlI IlIlbll (II Il in PIlipitalioll 11 II WI( Iplllh thnt (limiJlall till PIIOl dill 10 xtralllOlh (0101 (till dptl1minntinll Iph jill 011 tIll dtwlopllIlJIl of H HIli rOI1ll tlllbidity 111 hpl than I (olot rI
jJlIlpOP-ofallnlyi-I ( p(lllil1thb IIllijOI1ll turbidity or 1llt[lIinmiddotd d(ltl of jgtIp(ii(JlI l)~ lIltlkillU tIl plllltollllmiddottri( ntdillU al tandinu tiJlH~ (dlllilll wlli(h IhlllH(lill-- IP 1llutinmiddotly tnhll) t1ll1t an hlsl~1 oil the (oJlItlIlllItion of IIlhlHI Ill I(ill (lIPIipitat((L
TIll -I(p ill till jll()(Plhul HIP 1-- follOylt (1) 1l~UIIL uJ1lplls of thwl UJfJlllHl (II tliddl(l HUt dlipd 11Illtplial an lXIllltel with11 Ill of till nlnll ill t (oU tlllltIPlll[gtPImiddotatlup oil Iath at 11 Cbull fol 11 minutl I) iIP1lIin(middot(lohd til( (XUtllhllll Jltldl lip to It middotml ynlmlll til( (nlifild by (Illlifllgiuu HlId thlPl IlI nliql1ot of tIl (IalioPlllxUlltl nll Uillltlmiddotll(t to l-llll OIlIIlIllril fiuk- (1) For a trial Ilnditlg 0111 III tlll j liJmiddot~t IllHII IIjI to Ohlllll with lilt Pll shy(ilitnnl a 1(11 it 111 (Dod fill llli lIut ( ptotoJIIltlil IPtlllillg-- of pllllntnl or liuht tlUtllIlillal(I oil n (lpel OphotnJlllllI at rase hng-tlt (If 11 llJ Ill Ol It lollllil1lPtImiddott lloyidld with tIll P10]11 I 1110110shy
Ihlolllltt hmiddot Ii1llI Olllhi lIatioll for -1IpItillg UJlproXilll1l tply Wtl P ]Plwth )0 mp are HHlltk TIll Illldillg lliJtaillld fol tIlt 4-milutl tliall(~ll-
bull
bull
bull
RAPID PHOTO~IETRIC DETERIINATIOX OF R(BBER AXD RESINS 37
ing are referred to a table of equhmiddottllut~ previously p1(pa1elt1 on the
bull basis of 4-minute reac1inJ~ for tilE nmge of lot1telltlatiol1- of rubber or resins to bE elHOlll1t(led tmd gidn thtmiddot -tnnlillfr tillIP fill rUbbEt or resins aiter prE(ipitlltiol1 lwfolE photoIllNliI j(tltlill1 un IUade The r(middotnmining dllplllatt aliquot lll then HHllil up te ol1l1Jle and lpoundadillg ale marle ut the -tandillfr tiUlE iudklltll ill rhl tall1lmiddot for the final r(adillg~ -1) 111( milli1lnm or p(tCPlltllt- of lllhbpL (II 1(-in pr(s(nt are rpadholU a prlpan(l table of lquiltlput for tlll photoshymetric readings h1~l(l ill pnell e1-E on pxpPlilmlItal lhln 1111(1 u-ing as stimtlltlds pure luhbll in 1l1bbtl milllYb aIHI guaYllh ll-ill- lxIHlatt~ in resins detNIl1111lttion I
LlTERATlRE CLTED
(1) lUnSbull 1fl36 THE mURMIXTIOS IIF IOTA RE I III OOl THER llT~II
F1 bullrol IlY U(T1l0fll UfSlfi ~rrnrl r flm lt1 KEYS TI Bill Chern 114 44J-l59 illns
t1 ~ICPHHlObullbull T 1J3bull~ lUTHOO roa THE PtRInCAnu Or a(lIUl IRrIlHU It of TIn
PLRIHEU Htllllflt [ i Bill lallllall 111 Rmiddot 711middotj iIlus
I ) RHBERG P B Ul5 A METHIlO Or ~u(ronrll-nl Hi tIII rUIl[1 f71 ii illlI
bull 14 Hoss W flbull and HARDESTY J O
llH IR1ltDII Of HfITilIZfmiddotR DllIJS ltt 1 Yl fll Off gI bern JIIIlI i ~middotmiddotlf IIl
101 SPEltCE D nnd CuoWELr ~I L 1933 DETER~n-ATIOo OF RtBBER Ii nrllllpoundRBfR Iusr 1uI II1 amI
Em~ifl cttIliIa~~ r Ell i 71middot7i l11 (HI WALTER E D
1U44 ISO~nlS OF PRTlltSrr 1trHpoundV bull l UI n W lHHt (Tnmiddot 1ETS FROM GiYI l~iIl lItr Clttrn SII J UI titJ middotn9--C1 ilIu
17 J YOEbullbullr H lO~( roLORIlETRT 771 IPmiddot nl -W Yurk f H Plrwptric hmica
naly-II rimttry lUll XphHHlnmiddot~ y 1 1
11
HI) ~ fPHELolzTRf 57 111bull Lin xw Yk t H lt PhmeHt CblUlmiddot ila AnaiY~l~-(H lithrry and XIhmiddotILpfIY Y wirh enomiddot rrJlllrjr hy H KtlJnJU11 I
t~1I --- and ~ARVER L 1f41 nlua-w ~in L liLhr IS IP ll~ XIW Yrk
bull For-sale by th~ ~a~fr1nt~nf1ent Dt~c~~ogtnts-~ s t1i rArnn~ut Pn~~~ tJffieshy
Washington 5 D C bull Pl lU ~nts
bull
bull
bull
RAPID P1IOTOMElRIC DETERMINATION Ol~ RUBBEH AND RESINS 15
metric flasks and 01 m1 of protective colloid solution for rubber is added to each One additional5-mL aliquot from each pair of extracshytions is similarly prepared to serve as a key to the standing times for the final readings as indicated in table 2 These additional aliquots are first made up to volume with the precipitant acidified Do-percent ethanol mixed by carefully inverting the flask three or four times] and allowed to stand for 4-minute periods before the reading is made on the colorimeter Vith these preliminary rendings a~ a basis the standing times for final readings are taken from table 2 For example if the colorimeter reading in rubber analysis at 4 minutes is 655 then the standing time is 15 minutes
The two rell1Lining duplicate aliquots for eath extraction are then made up to volume with acidified D5-percent ethanol mixed by careshyfuIly inverting the flask three or four times nnd allowed to stand for the required number of minutes as established by the preliminary 4-minute trial readings (table 2) before the final colorimeter readings are made on the contents of the flasks
TADLE 2-St(llllliIlU time for variolls (OllccntratioIlS Of rubbcr or rcsins aftcl iJleaipitation bcforc colorimetric readings mc macle
[5middotml aliquots of rubber in methyl isobutyl ketone or of rcsill~ in ncetonylncetonemiddotcellosol e 3middoti both made up to a 25middotml volume with pr~cipitantj readings on lvolyn photoGlectric colorimeter with i20middotml (690to iiOmiddotD11) filter and Umiddotml aperture]
RUDDER I
Range of colorimeter Approxima(e S~nuling i Rnnge of colorimeter Approximn(e Standingtrial readings after 4middot range in conmiddot tJIIIG for trini r(adings nfter 4 range in con tifillnlOalcor minute stunding time tcnt In tiSSU(l Unnl I t I t (rending IIlIDU C stum Illg lOW _ tent III Issue reading
Percent Villlits II Perfe~lt Jfinul 955-999 bullbullbull bullbullbullbull 09-01 00 01-03S bullbull ~ _bullbullbullbull_ Jl-O9 10 743-954 bullbullbull ~ bullbullbullbull __ _ 43-10 30 1420-550 bull ~ ~ 137-94 5 6_3_9-_74_2__bullbull_ bullbull bullbullbullbullbullbullbull_-_---- 6__8-_4_4---___ bull ~ ~ bullbull ____ MQrcthan 13ibullbull_-~_ _ ____ 15_~elow t~ 2
RESINS -----------------------------~--------
957-999bullbullbullbull ~ 139-01 60 11419-amp11bullbullbull _bullbullbullbullbull ~~ 13~5-939 10729-956bullbullbullbullbull_ Ii 25-1 middotJO 30 ~gtl2-40(L bullbullbullbullbullbullbullbullbullbullbullbullbull _ 2025-1320 5 595-728~~~ bullbullbullbull 8 as-G 20 20 IBelow 292 bullbullbullbullbullbullbullbull- More thun542-591 _bull ~ bullbullbull_bullbull_bullbullbull 038-039 15 2025 3
I Precipitated with O5middotplrccnt HSO in 05middotpercent ethanol When the npproxilllull concentrntion of rubber or rcsins in solution is not known trinl colorimeter rend
ings atmiddotJ minutes s(nnding till nrc mndelS n guide to the required finnl standing time indicated in the last column III prncticc UII cxtrn nliquot is prcpnred for precipitation and thIs is discarded after the trial reading is mnde
3 lrccipitnicd with OmiddotpcrccntlhSO ill HO
PnOCEDunE I-On UESIliS ANALYSIS
The procedure fol resins unulysis is the same as that indicitted for lubber analysis eomiddot(I]lt that f he -olyent js acetonylacetone-cellosolve ~)-7 tht precipitant js O5-perctnt H~SOI in H 2 0 and 01 1111 of the protective colloid solution for nsins is added to each 25-m1 flask conshytaining the aljquot of the extract before the precipitant is added
PnOlmmlHlC INSlHu~mNTs UECoIUlENDED AND CALCl]IAlION
OF UESurlS
Photometric readings of percentage of light transmittance (T) ale made on the Coltnum double monochromator spectrophotometer at
16 lECHNICAL BULLElIN 920) U S DEPT OF AGHICULlUHE
750-111 wave length or renclings n1( mnde on a colorimeter pLoic1eri with the monochromatic filter eOIl)Il1l1tioJl for sllecting the npploxishymate wfLYe ]cngth at 750 1Il~ For routine deterlllinations the Evelyn photoelectric colorinwt(r ployided with aTW-lllJ filteL is IC(0l1111HIHtll
The liquid in hich the preeipitnted lubber uld rcins are susshypended is pOll(d very cHrdully down the ill~idl of th( clette o absorption tube to lLYoilllllC fOLll1ntioll of ail bllbblls Aft( LUbbet find resins preeipitation wlwn the EnLynpho(otkcllie (olo1imetll is used the readings are nmde nft(L thl standing tillll- hOWll in table~ It has been foulld (OIlllliellt to 11lPtipilatl tublwr 01 llsiIlS from the aliquo(s at ~-millute illtlLvals This allows stlilieipnt tillle to check the eOlolimet(r and to makc 111( lNHlings Vlwll a ehangp is IlltHk fLom onc rending 10 the l1lxt it is advisablp 10 llle the clIvctte 01 absorption tube nt lpast twkp with slllall p(Iltion- of the llllltiol to be leitd
After the colorimd(L lluding lta e becll Iltndp till IlIl II igllIlllS of lubbel or resins or thc lpL(el1hlges pnslnt in Ihe aliqllot are r(u1 from cal ibmti(Hl (urVlS (fig~ 4 and raquo or from plepn Led tables of eqllivallBts baecl ill each (liSP on (x[lerimPlltnl data The results are expressed as percentages of dry weight (S hours drying nt 100deg 0) of the original tissue The errol lltle to lCflyjng the insoluble residtH in tbe voltlllletLie pxtLHclioll flflsk wlwn the pxtrnetis being mnde up to YOlllmC is V(ly slight sinlte only (U gm of tissue is used FOLroutine allalyscs lhis ery slight eLlor mny be dislpgnltec1
EXPERIMENTAL RESULTS
The experilllCnlal reslllts Oil hi(lthp method- of tU)lPI and l(sins analysis a le based ttl( d icussld blicfly hlrehl
PHEPMINrlON OF SAlULES
No difliclllty was expPtitI1(ed in pltparing slmplls of llllrscly-glOrt guayule plants 1pss thnn ~ YPH1S old 101 rllbbpl alld IPSills analysis In the cnl of Odll filld-gl()n gllayull plants PIIOtS hopel mtty be introdmp(l by the custOlllalY Jlwrhod 01 pICpalillg Ihp sampl(s 101
HlutlYHis as is lwipfly i n( ita ttd ill th is s((tion Smh enOlS do llot nffCct the ])lCcisioll O[ t1H llwt hotls for LllbbtL n nd Il~in~ nnn I sis i nee till) are due solely to tIl( tbsup--ampling (llo(pdule in thi (a~e of oldeL field-grown plall TIll 1lllt1lOcl of salllplill7 fipld-gl()l1 plants JllOLC than ~ Y(HrS old thenfort Ieqlliles iurtlHl jnttigntioll
lgtAHnOILr~G FOR HEllOVAL OF UUVLgtS
Parboiling which (onisls in boiling gllltyule plants in water [OJ
8 to 1~ ~ninll(s ~s col1llllonl) uSNl a~ n llHans of Itlli rCnl()y~l prior to drymg nnd gllnllng It I~ tHI([())P ll(e~Sllr to ltItLeLnunc all possiblt~ eflct oi tlti PLOtPlllll( )ll (Il( final results Exp(liments have sh(nm that (helt i- fl Flight loss ill til tmiddotjght of lOO(S and 4(ll1S In I typi(ul lXpelillltll hlu1llHs of ~- ii) -1-ytII-old gllllll( pllllb were Italnd at randolll Olll ( of talns wa- paLllOil((1 and the le~es (1( haIHI-pi(kpd [lom till o( hpJ Ht Both pis (1( dlipd for 48 hOttlS at (i) C in a llI((lwlli(al (011((( ion Oyell Th( lpsult are SUI11111I11izNI itS follows
bull
bull
bull
bull
bull
bull
RAPID PHOTOMETRIC DETERMI~ATIO~ OF IfCBBER A~D HESI~S 17
Dry ucilht lust ill lariOilillf
Plaut (pcrcrllO 1 1 -I2 ___________________ _
213 _____bull _____ bull __ _______ ___ ____________ 12 2(
pound(111_ ______________ 1 R
4_______________ _______________ __ _____
A __ bull __ -_
The efred of parboiling on till final lllalp i SUllllllatmiddoti7(middotd ill figmc G Rubb(1 lecoYelY w(t about 1 percent higher for parigtoillltl plants and lEsills re(ovelY somewhat o-er 1 i)(lr(lllt 10Wlr The (Ii tference in lublH-l r((o-elY cannot be ae(01111tltlt1 fot by loss in dry weight _ due is to be found in a study of thE grinding lwhadol of a parboiled and an unpnrboilEcl shrub The grinding of the patboiled shlub in the hnml111 mill is much fadlitated and ns a rule for tissue with a rubber contCnt below 10 peteent llO aggregates of rubber deelop in the 1Il11ehinr during the (Jpelatioll Yitll the unpnrboilNl shrub some dillictdty may 1)( (lxppliellrl(l Sill(( sOllle of till sti(ky ltxlldutl Oil the plant may scI( u nlldei for the fmllHltioll of lublH1 ngglPgates Til is apparently explnins the npparlllt los in ruhbpl frol1l the llnpariJoiled hrllb as eompnlelt1 with thl palboilld (fig (i) TI1(loss in r(sins
II
RUBBER
10 f-
Ishyz LIJ 0 0 LIJ 0
9 --RUBBER -shy-------shy
-- RES INS -shy---shy-----_
IJ) 8 I--Z IJ)
LIJ 0
0 7 f- RES I NS -0 -shy0 LIJ III III J 6 f shy0
LEAVES REMOVED BY PAFltBOILING
5 f shy -shy - BY HAND PICKING
4 I I I 35 30 25 20
SCREENS (SIZE OF OPENINGS IN MM)
FIGlRE Ii EtIe(t IIf pnlticlp sizE Oil lEcorPQ- of rubber lind (iiil1s when lEgttiye wEre remond hr Pl1liloiling lind h~ hand pi(king ((Dlltrol) plllllt1lt groUlld in t hammer mill
6114038-46-3
18 TECHNICAL BULLETIN 920 U S DEPT OF AGRICULTURE
recowry from pUboil(d shrub may be due to the loss of the resinous exnc1ate during parboiling This exudate forms ns It SClim on top of tlw )iquol in the tank
On the basis of t1wse results the recommendation is made not to yaly the nwthoC of leaf lemoYal in any 011( lNi(lu(h project Then fltirly compalabh IcmLts should he obUiined
70 ~------------------------------------------~ LEAVES REMOVED
BY PAR80lLING ____ BY HAND PICKING
60
-I-Z 1amp1 0 50 a 1amp1 a
en 1amp1 gt1amp1
40en gt-CD Q 1amp1 Z
I shy 1amp1 30 a l shyx C)
1amp1 ~ J 20 I shy 0 I shy
10
O+--L__L-~__L-~~--~~~~~ o 10 20 40 60 80 100
NATIONAL BUREAU OF STANDARDS SIEVES (MESH)
FlGntE T-lJiMlil)utiun of l1Ultkh si~(s of gnll~II( tiSSU( JrIOllll(l in a Ball amp 1ew(1 mill to pass six dllIerNlt S(I(euroII 1(IlYes Iemoved from plants by palmiddot boiling 11(1 hand picking ((olltloll dpfo1iatld plants dried to 1I lUoistufl l0I1t~nt (If 01 to o) 1)(ICl1It ground tiSSlli IbalH1 1() minutes ill II ~i$hel
bull
bull
bull Kahn shuk(f
RAPID PROTOMETRIC DETER~UXATIOX OF RrBBER AXD RESIX-i 19
GHl~DIgtiG
bull Th~ entire pant 01 plant l)iHt a~(gt fl r(ll it pllllIIirU1ry lSillg fur J hours ntGi~ C prIOr tD t 1( plChmll1atmiddot rLlmhll III a II lItmiddot or n Ball amp Jewell mill ~n llltllysis of paldch lzP- nftl~l (oar-( IIindill shows that tlwy ar( about tIlt llllH fOl parbojlP(t awl IJllllluhoileu hrubs I fir 7)
The coalilly gloUllll ample i-- thPll Ildlll forI toUtmiddot at ni C afnr which it ha lllilobtllL(gt output of ~ llllut lII hmiddot- dptPlIIlilwltl by drying submlllpil- at 1110 fot hOtll- TIll 1 IIIIll i lltllt lmiddot0l111d hi a IluninHl mill TIll mo(lel uP(t in thi IIIk i 1I Hu IIIOilll mill as IllUllifill bv Hoss nnt Hartlet ( 1 -[1lt111- with n1ll1l1 pldushyrations ittI lilnbhell b rill HanlIolll V0ll11nHiol1 ElIillllmiddotrill (0 The size lutllihl11 iUlJnole So I ( 111m t ~ II t HUIII Xl) ~ I L~ 111m nnd So 4 lillllU1 11 ttllilhmiddotj 0 r tllP Imiddotlult~ p(lln-It willI t11(e Sll((IIiZtS with )arl)Oiltll awl uil)Jtllboiltd hrlll b lOwl1 in fif1l1fmiddot-- This hows t tnt 1middottttIl ~(I 1 llllll (Up jlllilnl IHlt that
r------~-------r--- ~ --r IHAMMER-MILL SCREEN
O~ NO1
NO2 ---shy U NO 3 ---II
I
bull lL
z
r ------ l 30 ~ gt III
i I Imiddot
i ~ I
I 1 I I
~ 20 I - 1 iii 1[ r 10 ~ ~ ~ I _ ~ I r A bullbull
o bull L-~__~__~~__- ~~ 20 40 60 80 100 40 60 80 100 200
NATIONAL BUREAU OF STANDARDS SIEVES (MESH 1
Yutln I i-tlillltiuli Hf pur id lZt f ~naY1l1 t middotnt r1 lI1 i ~ a hatlltlllI 1IIi11 to 1111 Lx IHtllllH middotIn Lt-anmiddot tIlllunl loy la1 litkh~ omrl t 1) tHul parbuih~ -t B ~ thmiddotfuliufptl ]~lahr thpt tu tt fit t 1 It+gtr-tt1 Jnui~tHn eunttlIt _~rnlitl tl~UP ltakmiddot~~ 10 UddU it~ 1 rtmiddot4~pt~middotK1~r ttakt-middot
bull So 1 gingt- 11 tt-liuin-Iy ltr~pl [lPlItl1tat of iilll 11animiddotImiddot- Eqltrimiddot tIlllll hnnmiddot llOWIl dutr fll llltldllllUU xtlutioH 11pound lnhbll lIl lP-ill frolll IolUlIl ~tlaYlllt tl-IlP by dlt IJwtmiddotlUlmiddot lItlilwd oil Ill 14 - 01
i-mllt 11111- -lwltld hi INd I li~ Ii I TIll lllhtIlttj of Itiu~ So 1 (lltll j thnt 11middotmiddot01middot lttwmiddot to amplil tltt Iollllli tilt art lpdnn ib
IntIIll ll~ i po--ihJI with tI lLllit Ilfltl[lll1t It honld l Plllplw izmiddotl rImt ilt tht h of -allllhmiddot with l lllblPl
~ontlnt of ill PPltllt til lIilll it i tlllt pll--ihl 10 11-middot t(1i Xli L
20 TECHNICAL BULLETIN 920 U S DEPT OF AGRICULlURE
Even with screcn No 2 difficult due to rnbbel tlcrltreCtlltiollS may be ob tl
encountered In thes~ caHeH it iH lWit to parboil the shlub fOL leaf lemonll and finally to dry to about 1 to ~ P(l((llt of tnoiibl1(l pound01 b(~t results jn ~rindillp in tlH hanmHl mill
It iH aclvlsable to provic1l thc hammer mill with a ground wire Hillel the presence of static electric (harges 011 tll(middot partkhH will ealls( Home of these to atlhelc to the inside of tllP (olltailWr OJ lila eallsc OI1l( of till pULticl( to form ngg1(llatls EIIolin lalllpling fl01l1 fhis SOI1I(I mlly be (onsi(h1llbl(middot
A1I10l1g the Holnllts with high boiling point that lIlay Ill IlHld in rubber anal)Hs I1IP Illllhyl n-alllyl ketolle methyl ioblltvl kptOIH diisobutyl (tOIH blltyl tHptate llethyl amyl 1Ittail (middotthyl(middotlllmiddot gly(ol diethvl (middotther and n-bntyl (middotthel (labl( 1) TIHse al( also I(sin 01shy
middotent but th( 1(~illS n1( held ill olution by the rll1)bpl pl(l(ipitant tthanol wll(1 lllbb(r is 1)J(lipitatNI (S(ll tabl(s alldmiddotl) On tIle basishyof the lxpHilllPlltH tll( btsf nil-round lolPlli -rol lS in 111( PIlHPllt method is lt1iisobutyl kPtonc wld(h was not IIltlllllfaltllllmiddotd ltIlling Vodd Yflr n A suitable Sl1lgtstit ute iH llHthyl jolllltyL htolt whi(h is l(porhd as llolltoxit UJ)
Clllos()IY(~ (ethykn( glYlol monopthyl (tIH1) blltyl earlgtitol (di(thyl(ll( gly(ol llIollobutyl (ti1(r)~ and acttonylacetOll( may be used as resins sohrCllts (table ] )
In the earlipr work with (sills analysis cpllosoly( alolle was selcmiddotet(d as a suitable solycnt Aitholllh (ell()~oh( alone is pxc(lllnt its rplllshytiwly gwatlL iscosity 1(I(b to bubbl( formation nft(I (SillS pr((ipi tatioll Thi- increased thp (xperimentnl (LTOI OIl of tltp othll I(sins solpnts tI((tollyla((tolH has the proppry of glpatly lNlulingshydH(OSity 11(11 altld(( 10 othr liquids This sohpnt tlHIeforl wa addp( to ((Uosoh( in slIflici(lJlt tlllIonnl to OPI(0111e the dinieulty On the basis (li~ex)le1inwllts ~ purts oi~ a(donyla((tOlll to I puts of (elloshysoh-f (bolll by olume) as Splldcmiddot(l Thp 01 hel Hoh(nl listed hutyl clLlbitol at l(llst the t((hnieal-g1lld( ploduct uSNl is appal(ntly not as good as eithe of t1w ot1(r two () a (ombinatioll of tlWSt
The SOlVllIts JOI liSt in tumlyzing artifkial lubbel$ hy tlw pr(senf method appllLently (lcllIHl on th(middot kind of llI))(I lIp-ityl (Jxidt is suitable Ol BUlla fi and hutyllthlI for butyllllbbl Tlwse reagents IlLe technical g1lld( Calboll amp CtllUil1t Ch(lllilai (OIP This Hllbjp(( hilS not bepn (XtpllHl(ly illwtigated by till WIit(I
PIIECIIIIJ-
All tlst fOl Ih( adlqlJalY or till IHllipitullb ll(Ollllllentillllll11Sl bl baset] on the plctisioll of tllP final I(snlts oiJtairwd with the methods The )redpittlllts s(1e((( n HpJ (xtcllsi( (xp(IimPlltatioll all HatiH~ factor (Hee fig Hi 111lt1 tabItmiddot (jH) Ext(IIin tllts llllTild Ollt hanmiddot shown that H Hatil-gtflltlOIy [gtIpeipitallt 101 1lIbblI is (li-p(IT(middotnt HzHO (c p reagent nil POll sp gl U-lmiddotJ) ill li-P(l(Put (tinmol by vohmlP liol (tllayul( Ipl-gtinl 1l)-P~ITImiddotllt H)~o ill Hl) by ollln( ii lL satishyfaeto7-y l)lp(ipitunt A solution of 1 palt of H~~o to 1 part of H~() (1-1) iI2So1 nnd abo yarious int(lIlIPdiat( proportions of tlllse suhshystanCPs giyp fait 1(511It8 but with till inlIptl(l ill [h(gt ratio of H~S01
~
bull
bull
bull
bull
bull
RAPID PHOTQlIEfRIC DETEMIlXATIOX OF HtBJER AXD RESIXS 21
to H 20 the )olutioll becollles somewhat vbcou5 and precautioll Il1Ult be taken to ttvoid bubble formation When it i5 poured into tilt Cllvettes
It should be lloted that both of these precipitants have an ftellleshymmiddottion It was found that when XHjOH was used in the rubber preshycipitant in pInt of H~~O~ the readings were -table l)Ut were not reshyproJutihk The lIl of XuOH in pInel of H 2SO j ran nHittble result as a llth H(HY(Pl WIWll til( li-P(l put lthatgtl in lublltl llnalysis or H~O illlP-ius anal)j wn-i uddint(1 thl eharalteliti(s of till liquid with pleeipitated ruhber or resiu in HI~P(ll-ioll n ren1 on the lpNmiddottroshyphotometel m tololinlPtprfollop(1 it lPgnlal lIlll II~ lxplaiHd on pHgP-I (Sl( figs 11 aIlIIl) Tid made it lloible to outain lEPJOshydlHibll tpnlt nntI (onplt1J1(Jttly till JpqnitPIl tlPgJPP of PJPcljoll
IIWIE(TI 1lt COl~101J)
Jtl thp ItJiPl middotxlwlillltnb hefoJ thtmiddot -1l]YIlIt allll pnmiddotdpitallb had lIptll ptoppJly adjutp(l it l fOllll tIuH till llP or a Ploltiw colloid -wll ltIi1)cJ [ttlJmiddotntl- imlIopl tll lmiddotpro]lIibility of the lPlllt JmUkllly ()Ilt 111 U lput lUlU illlihumiddot tOJllPOlUtl tpHd liglyeol teltlut( - llpanlItly IllmiddotlfP(] to lit til I1m t IHflll lImnnmiddott nftlr tlH filial prOIptlllll WtlP dlvPllill1 tlll 11lIlpfit (If thtmiddot [llltlltin lollohl wa Hot 0 natlv I1l(lhmiddotd III rlumiddot Ia- of tmiddot ill tllmiddottJmillaritlu it b [1 hmiddotjlmiddot til IIpoundgt Ir llH1 It liltr ill-llImiddottiT Ina lll ptlPII by it U( in ruhhfl mmly j 11If dtmiddottail fOJ tltt lllllmtlllll If thl plot pet in nlloid ~llntill tltlmiddotlImiddotmiddotlttlatiflll lIOlllllllhtiPI1 are iPllllll page
liTFHFEHliG COIOf
(hi II tht lllail 11111111111 that had til ill -111111 II urklll) om tlH method fot lublJtt tlIlO1 rpir- nlalv~i in plaut llllpll- wa ttl (lilll~ inare tIte (gt1[01 till to tIll ptP-PlHt f xi [aIWIIII- 111 TIlt amount of (olor varip from lUllIt tn -amp ]pplwHlI nlt rhmiddot lt IIf thE Hl(ltllial tllP part of till plllIt -lI11lhmiddot(l tilt hi-tlllY f tlll plaut mtteshyrial ~ub-lltInent to Itlllmiddotnmiddot-rill lliI 1011middotly OrllPI Inlw
In ruhlwr lrtl-i I Iii 1101 au Itmiddot 1Iplll11l by 111[ I--r ratmiddottilt thE -lllll]t with uptoIw or 1middotmiddotlIll-ol - wIdell [llllol- rlll loillriu nutttel autI thtmiddot lpill- Thi- howmiddotvt n(tnll- til lXtla -11gt1 ilt prlJ~edun) In lP-ill ltluay-i nllHufldy tlW[t j 11 1 1IO(PIlln fill the 11shylImya of hlulophyll Hwl rIlI-r middotIOII IHlttlmiddotJ dlH lUtl~ In plltIH withoUt alo aiftIriL till nmiddot ulttrll
111 pllIbIll1l Wi tilmiddotr hId h It-ImiddottHI tht Pltlpll 1 hlitlt lilt tlw tulllWlli tollImiddot uIwltllIIntut -lltUIhorlllllltll 1111 tIll tlettlllliIttwr IIf t 111 lWlrl-Uamiddot of bdt tl11blLlittUhmiddot r [1 tItmiddot preshyj
lipitatifll 1lJ llllllWI atbull 1iI- in III -1nrmiddottIi fHlttalldh nlrillU~ amount rf middotlorilig lIUlttll Iii lhll of ih lltmiddottllllhottohttt~l l~ol()r infrtl Hm II upd 1 rwmiddot tld~middottilmiddottll PlllItlhi~ f it j proYitiltl with tIll lilP--UlY tU(jlIdlllIlml tIltmiddotmiddot lllklllUIlI
EIECTIol OF 1 [EGTH~
-Ptfmiddott ral tracilull ru~lI gtIll fr 1 nllb t ~xtltd 1 lIlt-th vI iobmy1 ketommiddot lWtl rill [ Ixt lttltt ll UttollylaIiIitt1l11I1t~ ~-I itoiu YtHil)u~ typp of ~IHaylllt f i lItmiddot art hraquoil ill fio1ll1 ~l Th~ lp-nlt fill I11oohl uio[1t ttl willlr til tltN- fur rht IUiXtIUt iwliutll
100
22 TECHNICAL BULLErIN 920 U S DEP1
90 bull eo
I shyz 70LLI 0 a LLI a 60
LLI 0 50 z
a ENTIRE 2-MONTH-OLD PLANTS~ 40 b ROOTS AND BRANCHES OF ~ 3-TO 4-YEAR-OLD PLANTSen z WITH LEAVES REMOVED ex 30 a C CURRENT-SEASON GROWTH OF l- )-TO 4-YEAR-OLD PLANTS
20 WITH LEAVES REMOVED
d LEAVES FROM 3-TO 4-VEAR-OLD PLANTS
10 A
0
a Cd 100
b bull
10
80
I-Z 70LLI 0 a LLI 60a
LLI 0 50 z ex I shy 40 ~ en z ltI 30 a I shy
20
10 B
o~__~__~__~~--~--~--~--~----~--~--~ bull350 400 450 500 550 600 650 700 750 BOO 850
WAVE LENGTH lM~)
FJGcm O-Sll((middotlllll tramaniW1IHl (mrpS f(JI (xlmll 11011 n J1ll of jlta)nle tissur ill n 2--m1 Y011111P of (A) Illrthyl ji1I1J1ltsl krtonp 1111(1 (ll) nt(middottQnyla(umiddot tClIc-C(l1osuln a-i
bull
bull
bull
RAPID PHOTOlIElRIC DETEH-UXATroX OF ntBHEIl AXD HEstxs 23
ThE dula Pl(S(l1t(lltl indi(ntp Ihut 101 Illp ulimls llHthyl liohutyl htOlIl (lxtrHts (lI(I r(dolls of Il1Hxi11111III nigtol]gttioll wiH1I all (is-lIb 11 cOllsic1(]((l n1( blhn(11 wn ( ItIl( Its lIO to () I1It~ nlid Ii to Iii mJL
WhllNIS tlw I(gions of 1middottnL(s( light 1lnlllittamp al(l lgtPlW(PIl wan Ipllgtltsnr) to Ii nllt jW) 1I1JL nlld alio Silllill1l 111l1b (n SI(lIlId 101 nc(ton ]altmiddot(fmiddotollp-(llloolp ~ pxt Ill of 11a 1111 t illl TIl( (1101 du( to lolo ill tlw litlltitl a 1Il1 lullll(I tH lPill- hanmiddot bpllI PI(_ ipitated ma he 1((I1((d to fltI ynbhing poillt II ph( illg OJ illshylmiddotJall(( WIWp balld nhm ()) IIIJ1bullbull[1I111 lxjlPIitllll1b Illln -h()1 that Ih( lIIot uilahl( WHYI lHlIJ fOI 1-1 ill 1l11J1l(I HIH11Pill- illllllrsi i-in till IlPighl)()lllll()(l of ~llIl1lt bull
bull UIlIilHlIy of n typhn] lXPllillllllt to )10 l1iP(tiP ((JIlllo( of (ItOIS dul to lOIOl in 1llblnI Hnd Iill xtnumiddott 11(11 IIIIolp t jUl i p1llelll((l ill tub]lL Till llhlllt- 1tpIO]II Hnd ((llll~()h whit-h UI(I ](]Hllilltl n 1I01lllIhb1 01(111 lxt 11111 IIll 1llll)1 nmtp[in I and )(middotills Tid IIlnkl it poiblp nftlI tlIp uplll1tillll or tlll o1PIl( (0 [niH lip 1Iidl1p~ of lI111 11111(( ill lit ll11l1)[1 (llnlIb nlld Ihll
Sl(ll n ol1lliOI with tllP olnl IJllt illiollt HIl Iltlllll llllI (Ill ltllthpl prpipitnnt j Ihll1 nddld OUI ha a lIilPt lP( of till lIiciPlw of WH( lllIgth 7) lUI- ill llilllillatiu (nnl till tll Ixtll1I101l ()lll~
Tuu tmiddot-Elilll IJl flrldillY 11-1111 lrlllI IjfJI til islII 1 1(1 ([rllt IIIIIJIlIr JiIlIt~ if 1Il( Ihll 111111 k til I III Ilrln I 1Intd tf 11111 JiSf fill I I II I tIII Ilf Iilltl 1f1JlIIillII1f I Till 1[ 1 IId 1 (I (middotIt 11111 (I1I1iI1 1lf1IWtlfJlIIllfflr p middottrllhIJ11 II J III 7IImiddotIa 111 111 lilt jJIp 111 wilTII
t~t tnVIli~ ~nn r kn t~ i tmiddot ~~l Jr 1middotmt ltlTt
HmiddotOtt ~I~ lin t I ~ 1 t~~l ~qrmiddotthtmiddotrtwb
Hult-middottltlru t T Hw ullut rHtt~ r II I ~ PH~lllt
A~tmiddottHHjmiddott~rjd rl ~gtllh 1 tn~th~ ~ ~ middotI lt~ b w bull hmiddotth~ 1i~lIhun 1 Ii tnl Illd1 -11lt1(11i lullI lUI tJl ll~ t1~11n( I Ihan1li flfttIJir Ult I Uuhtltt ahuul l(hmiddottHmiddot~t trv r fti HIt lftbyl tlonhUt)1 k_hIl( 2 m~ fmiddotf tuhlHmiddotr In mlth~ llmiddotlf- 1 t r
t r_~ t j
Arhlitlltd ~llIIDHl NcWitn1 ( Ar-(lt()nc~middotttrrtrt ritJJI~ -Iu nllJtl4-middotr
ACtmiddottflnp fmiddotxtrn( ~ T-P511ftf tn mtmiddotth~ 1 ~difmiddotut~ kdn 2 nltt ulruhhtr in Un-tIl lltbu )J~IYt
rUth(Hl~hltlft HhubU
Illlh(I(t tttUtUt hUbtl til J ~jlitl(J Hilllll trtIIImiddotjtl1ll
(UShl I ~tlO wHllolH rulh r (middot1111$0]( J~rru t t )lthyl 15bullbull1middot1101 klll1l
Ili( UHUicbcul ~((i1rUtl ~ulu1iin 1middot lIUIll Ilti lrllltlllt I Ruhhr llt1thuI r1 -1 Irld
ltlt1111Sh 2 nuz f)rruhl~rm nlith~l tu- h f nt nil~middothgt(H] tlrlftmiddot 9lUtirtl middot1 1
rlcltfl( H(l dnllltml it
(IISllhH~rI( Iultruhtr CII05 1v ltTlft I 2 UI~r ublwr In llldh I hlt~1 11) lgtjdvr(llsl~9rlltmiddot middotlmin ~ I~ gt AIHItilltl no IrttipHallr iI
~ Bbnk 10ol m(thyl i~tmiddotut~i kdHn H 1 m1 j~~ l1rH-t lt~tlfltmiddotn sf n it ll HltlMjftr~nol O2~mlJ ~U~1o-ulp ti~tW -xtra~middotl(lt1 ltt 411 ml bull ie f Ct- kft rt t~ tirattJ middott ill r u l1kn ttJt
in metltl isobutyl kNqnf nn~i mljp ur tmiddotmiddot ~oml ~urr tttl i t w ltJj1JH kt 4t 3 nlank 1 mL((l1t~rthmiddot(middot mI mttr~ ~but a kmiddot tmiddotc d 11 ~ gtli~b~ hifIAft- fl~ lL lnti 149
ml8(dlfilll BO bull 02 gm guayule U$Stl(middot xUlClt-l tf(h tft wI n nmiddotmiddotmiddotlgt 1 lznt on tmiddot ~Jt r~1 ~~u~~ H~ iI~ thT
24 l$CHNlQAL BULLETlN l20l S DJltJPT OF AGHl(CLlOHJltJ
In table a is pl(sentc(l such c1il((t edlt1tIHC showing that thc (0101 Ixtrnetccl from guaYIIle tisslIe wit h II(P(OIl( n nd (pl1oso[yc is cll(div(ly sCIe(nec1 out by the s(lp(tion or wnw length )0 miL Oil t1w SI)((IOshyphotonwtpl This tnb]p all-HI ihos thai thl Juhlwl altl(l((1 (nn IJl quall shytitntivcly 1(I(()(Ipltl in tIlt PI(ilIH( or Ih (o]OIplnwPIials and Illsins and tlmt Iuhb(l WtlS nppnlllltly 1I0t (xtltI(((1 110111 11l glll1I1l lisslIt b~ tlHSP SOhlllts Thls( ((suIts ginmiddot (OliIHillg (idJt(( that t Iw IISI of waYl llngth i)ll 1Il) OIl till SppdTophot OIllltPI ii t hl 1101(1 p(oshy(ellule in photolllliTie IlIlalysis of luhhlI OJ l(sin-
SELEGTIO- OF )IOiOCUHO)IAIIC ItIIm ((1111110
On th( basis of th( IPHIlb shoWIl in tabl(l 1 al hlllpls (1( IIln(lp to SPCtl lC the PIO]Wl 11101lO(lIOl1ln til Ii ltlJ ((lIllIJi nIl ions 10 llIiOlS (oIOlimet(Is 111(gt 7W-Ill~ filtpl flllnhwd 101 til( I1~lI1l photoshyplpct1i( (o]oriJl1ltll fol which Ill( (hlll(IlIiitit~ oj t hl Ilda he light ilUIlBlIIhiSioll (t) elll nn -hO11 ill fig1lle 10 iws satlsfa(lolY IPshysultl 111( iiO-mL HitlI olllhintioll 101 whkh ttp (middotIatinmiddot light tlnnsmission (ullmiddotis a 1-0 showlI ill figllll (I is -nthdnlto1 hut this is not stnlHlnld NtllipmPlli
Up to fhl PlPHllt lIS(middotflll pound11((1 (ulllbinntions jn lltl iOO-I11L Iunge hayc nol bllll SlClIlld 101 lhp Klpt 1-1I1l1I11PISOIl (olOlinwtll bu fnltlwl nttCl1lpti 1( )(illg IlIHd
TJIpound OF ST~lmW AFTEH HIIJ1EII Oil HHSIS rlll~CIIITTI(J
~ considl1ltiol1 of ttp lillll of Inlllling af((1 plpeipital ion of 111gt)(1
01 l(sinSTlOIll ollltionis impoltant J(jl~ thC1HI(Plltngp of light IInIlSshy
11 rshy10 f shy
09 f shy ~750 Mil- DOMINANTI
~ 08 cshy I WAVE LENGTH z
I III III i O7 - I III
~06 - 05 shyw
a
Igti= 04 - 720 Mp DOMINANT ct WAVE LENGTH- ~ 03shy
02 f shy
01 t shy 1)O~~~gt~- J 600 700 800 900
WAVE LENGTH (Mp
bull
bull
bullFIGlRt IO- COJllPIUlItiw ~IW(middottltll tlnIlRlllii-lion (II (IllP( 101 1i11(1 olllhinulloll
with dominllnl Il(lllllgths at 720 and 7iO lUi
bull
bull
bull
HAPlD PHQTQlfE1IUC JjETER~lINATION OF Rnmrm AND HEtiINi 25
mitted (spertrophotoll1eleL lCuding-) Ol light (1 (tClcrl (phOlOshyJluol01l1et(L lcndillg~) i~ StlhjNl to (hangl
]fjt~l1le 11 and l~ show that ill til( (asc ot tJaugtIllitteltllight llJHC th~ (x[llliHlllIlnl (oIHlitiOllS tllpl j lilst n dtlln-e ill Pll~(lltngl or UllllslllittnlH( follrnY(l by It ptJiml of lClntin stability with only sliuht (1111 tHn- a f(Pl a lIt1ll1btJ of minutes The light t UIllllitblllll t l(1 ill(Iln~(s This lIIay IJP llllllJltlli7P(ll1 ffl II ow 1Ilt )( f(( darI oliIII tIIlIlNlIlitt(IIIlfJIIlh (iditilIiid Ilil1 pllIipintnl )uoshyIn Of ( 8inx in (~f1( I~iUII i~ Ild stahl I 11 itlll If 1inl nh prlshyilli(ioll of 11l1d(1 II IJIX f) jllIli II (fJJltfiIIlilty slllMI IIriot 1) IIIPldUnl1i tll(I1I rllltltilJl oj tJi~ Jlt jiot IUN ilUf Jxl1 will tIt( tOWI IItlllilil I 1llIlllblJIol I ill I~11l11111 d ill till ifjuids JjOI scnttplltl light 011 till phololltHJIOIl1lttl till dilPCt ion 01 elangl b tlw IPrfIi (If that illrli(atPll rOl tlulll1Jittp(lliuht It Itlll b( llluliJr I-(Pll that if l(middotndlnJ- IIIP mad n itl I t lIP ~()ll1d()lb lpalll this pllioJ of nmiddotlatirp tuigtility tllP llLot tIOllt thi Olll(P (nil bl IPdUCld to tIl lltini III 11 Ill TIll l~adiltg (illH~ bbll Oil tlHl datn rUl lublwls and llsinlt Illl ginll ill tnhh
50 r----------------------------------------------- f shyZ
~ 40 ~----~W~A~V~E~LE~N~G~T~H~7~5~0~M~P~~~~ ~ --------------------=-=-= ~ 30 f- WAVE LENGTH 540 M~ _z _____ ___ -=- __ _ ~ ------shyt ~_=---=-=--I GUAYULEIII 20 -Z HEVEA ltt II KOK-SAGHYZ f shy
4 6 8 10 12 14 (6 18 20 22 24 26 28 30 STANDING TIME (MINUTES)
FIlirtn 11 Emmiddot of wav hll~rh Il li~ltr tlall~lIIit1alHl aftI IUIlItHt -Imlli lug 111m for guaynh llmiddotn 011111 middotiolIlJh~z 1111111 llijlitul1 flolll 1lHlh~ll1Jllryl k11II11l ~(lilltlll h~ lwitlitll 111Inu1 111l~1It1 2)1111 o1U11111 (Helillins on (illllun tlunhll IlIIJlllw]ntllW111 lutl(I[lholtllllltlt with ijUjt Wlnl IHI Ilf1 I
11 EFFEGT OF Hbli 1 -()JXT10~
Tilt lnblwl ~()h(llh pxtnl( till IPillgt ubo It 1m nllu1- bellt -~atea thut ~lll 11-111- tUP olnbhmiddot ill middottIIlIlOl ~1It tlWIIJI( my U)t PIl (tlIHatcl WIth tl1l lullh(t I tahle lJ 1hln 1- -1111 tIll (llllstlOll of nny p()~iblt tITptt of XtIIl11 diflp]lws ill ((JlllPllttUliollS of 1l-in lil lolutioll alollJ with till 1lIltbpl TIU data ill wbh +ho on tIl( hn~is of (olorilllPill ladillU thaI tll( IIUOIl1t of lnbbll Plllipirntld 110111 Ilwthyl olnlld kptOlll olntioll IJ 1li-jHlllnt 1l)04 in 1-llltlIllt ethallol)- not amlll hy thl llllNlI(l of llvin aU1ouut of llins inolution bull
-----
26 rECHNICAL BULLEfiN 920 U S DEPl OF AGRICULlUHE
100
90
80(I) C)
z Ci 70 UI a 0 60 a ~ UI ~ 500 ~ 0 I Il 40
30
A 20
0
100
90
(I) 80 C)
z Ci 70 UI a 0
60a ~ UI E 0 50 ~ 0 I Il
4-0
30
B 20
0
--
--shy ---shy---
2 4 6 6 10 12 14 16
---shy= ~ ~ shy
-
2
025 05
10
15
20
25 -30
35 40
SO
-60
=70 80
16 20 2224 26 26 30
OS
- 10
IS
20
2S
30
35 40
-50
-60 -70 -80
bull MGPE 25-ML
VOLUME
bull
MGPER 25-ML VOLUME
Florm 12-EtTld (If till1l or Slllldill~ 011 light transmittallce (01 (A) gUllyulc lnUIl(I plccipitllitd frOIll llltt h~l isobutyl Ielollt solution Ily neidilic(l ethanul bull null (B) gUllyule ll~illii pre(ipitated flom aeltoll~lllcetOlll-Cl])osolY( 3-7 solushy11011 by H(illilip(i l1U (HPlldillg~ nt -lIlillult Ifllpluls 011 Evelyn photoelectric colorimellr with jU-lllp tlllll alit U-1I11 npN(lle spp also table 2)
bull
bull
RAPID PI-IOlOMEllUC DElEnMINAlION OF RUBBER AND RESINS 27
TADIbullbull ] 4-ReZation of amiddotmount of middottbber pleeipitate(Z Oln metltlIL isobutyl ketone 80lutions by OS-pereent H 2SO in 95-pere(lIIt ethanol to umollnt of resin8 udde(l U8 indivute(Z by colorimetrio readinU8
(Rubber ami resins cnlculntcd on bnsis of amounts in 5middotml ullquuts of extract from 02 gm of tissue in a 2fllll olumo( bull
Hubucl r~cocrell whcll rcsins nddcd as IndIcated Htbbor al1dcd (pllcollt) ---shy
__________bull_________ ~_12rpcrc~15011crccllt 7511crccnt IOOpcrcent
PerCtllt ercellt Percellt Percellt Percent o o o o o) 50 250 263 252 25000 500 500 500 500 700 750 750 751 749
1200 1250 1250 1250 1250
EXTRACTION TEMPEHATURE AND TIME
Typical experiments to detllmine the time required to secure maxishymum extmction of rubber und ltsills at 115deg U Ilre sUlIlmarized in figule 13 the solvents used-methyl isobutyl ketone for rubber anrl Ilcetonylacetone-cellosolve 3-7 for resins extraction-are very eflicicnt since under the conditions indicttted maximum values were secured after 30 minutes of ext1llction The most eflicient liquid for the bath (lig 1) used in extrtlcting rubber or resins is ~ high-grade cylinder oil (S A E ~O) The sand bath and such liquids as glycerol have proved unsatisfactory
RUBBER AND RESINS STANDARDS
According to the National BULeau of Standards 1-_ lhclc Is no gellcrnlly recoglllz(d standard lIIutcrlul [ior II rubber standard] The rubber hydroCllrbon ill llifferent samples of conmlcrciul smoked sheet or pale crepe from heclI pluntlltions nries from l~ 10 04 llercent of the totul nutletmiddot the most 11Ioruble conditions Of preparation
McPherson () has described a procedure for the pLeparation of pure heve~ (Hevea brasiliensis (H B K) MueH Arg) rubber from crude rubber or latex In the absence howevcr of ~ generally recogshyn12ed stalldard for rubber hydlQcllrbon [caoutchouc (CnHUs) xJ the standard adopted was that of the relnthely pure product secured from gunyule tissue txtractiotl nccording to the Spence-CaldweU method (5) or the motlified PIOCCdUlU of Hohnes lind Haasis (p 2) The details for constructing the calibration CULes are given on page 10 Standard rubber samples apparenl-]y can be stored for a long timc under the conditions des(libed on page 10 The duplicate colorimetric lendings for glULyule rubber newly extracted by the modified SpenceshyCaldwell method were ()J2 ench as compared with US) each for the sample extracted by the same method but stored 1 years In each case colorimeter rcadinllS were made on mixtures containing 2 mg of rubber in It 25-1111 Yolume
The selection of tt suitable standurd for guayule resins presents some dilliculties Tll(~ acetone extract of gUllyult estimated on (l gravishymetric busis~ for instance proved to be variable depending on the type of tissue sampled or season of sumpling because such fractions as
COllllllunlcntion dul(lt1 Octohtr 22 11H3
28 QECHNICAL BULLEQIN 920 U S DEPT OF AGRICTTIIlURE
16~==========================115 shy
14 bulli= 13 z ~ 12
ffi II Q
10 c w 9a w
8gto () 7w a
6a w
5en III ) 4 a
3
2
A 00 5 10 20 30 60 90
14~------------------------------------------- bull13
i= 12 z w II ()
a 10 w Q
9 c w 8 a w 7gt o () 6 w a 5 If)
z 4 If)
w 3 a
2
o+B~~__~__~____________~__________~ 5 10 20 30 60 90
HEATING TIME (111 NUTES)
lllGUltE 13-lDffect of time o( lICntillg O2-gm samples of gunynle tissue with solYlIt nt llfio C on lo(OVl)ry of lllhlJer alld 1Isim Lt HlIhblL extracted with methyl isohntyllwtone B resins Cxtll1cted with aCftonyla(etonc-cellosolve 3-7 bull
chlorophyll are weighed along with the resins in the acetone extruct but are not estimated by the present photometric method (fig 0) 1he use of a diffeJent stanclttrd waS therefore indicated
bull
bull
bull
RAPID PHOTOMETRIC DETERMINATION OF HUBBIm AND HESINS 29
The resins standard selected is based on n relatively pure source of resins the rcsinous exudnte 011 the stems of guuyule plants IJldimishynary expeliments with the resi nouS cxuclate from diffcrellt gllayu Ie strains of various ages indicatc nHlt there is little YaLiation in this subshystance on the basis of Colorimct(r readings 011 2-mg aliqllots of 01shypercent solution in It 2i-ml volume (tabl( li) Expelilll(lnts have shown that the air-dried (xuclate contains 3RtOH p(Ic(nt of -volatile matter This material is l(latiyt~ly stablp ill (OlllpoBition and is npshypurpntly on ly slight ly hygroBcopic as shoWIl ill Ia bl(1 1 Tlrp Ipsinolls exudate may be jJleplpd in two wayi-i fl liSP as a stallClHld-(l) the clpan exudate is clripd iol Ghouls at ()1deg C at W indlPs of a(lIum Hnd aftclbCinOglOund ill a molfalis 1)I(spI((I intn airtight COllilinel OL
(2) tllP Cx7lclate is clissolllt1 ill a(lhllll and filtplpd PlactieaJlyall of the acetm1l is thpn lYapolntwl olt OPI a stlam or atCt hath and Ow residue is dripd ground an(( PI(sPIld as ill tllp fin lllethocl Tlwse two prepalHtlolls a1( (ompalpd in ta hlp ) 111( (((tails fOl ~t()lil1g the resins standald and (onstlllcting the calibration CUITPS alc given Oil page ]2
lAIIIg fi-CUIIIllrsoi (lJ lIr-dr(1I IIIIi 1((11 II II-()I-tr((l l(sil~ 11111111(8 of I II 1111Ie
[Colorimetric rrndill~s 011 1~I11 phulll(Iclrie eolorillJct[lr with i~()middotmll (100- to iiOIIIIl) fillcr [lnd 5-1111 lIperture preeipitantl part ofO5middotPIrctllt 10 to 5 paris of IIOj
nupliclllc(oloritwt([
nIl(lin~s (hIlSlcAg~ ofSlmillXo JrNliltlCllt of fPsiJI$ L1Xtlrlntp on 2 IIIg ofplanls fllsins (XIHIIlt~Jwr 25-1111 vol
tII1(1) 1
leflTs Various _ bull ____ bullbullbullbull 3-9 Colll)Josiltrlairmiddotltlricfl bullbullbull nf)2 002
])0____ bullbullbull _bull __ _ bullbull ~-l Composilld (ri d at n5 C in aUmiddotimh lWUUllJ for l (jOuj(ja hours])0______ bullbullbull __ bull ___ bull 3-0 COJIlpositld disso]NI in neptolll f1l1erNl fl(lf()ll( GGO i(jO (Ivaporntld olT OV(1r Stpl1l11 halh TesidlH drl(ld I1t fi5deg ( ill anmiddotinch VIl(Unlll for 0 houlS bull
middot106 __ bullbull _ Jir~c1rild_~_~_ _~_ ~_~ _ ~ ____ _ __ _ OUu GOifina_~ ~ _ ~~_~ ___ _ _fln~ ~~ ~ ___ ~ __ 6(imiddotI tiliA H)[_ ltlu bullbull i18 tisSflOabullbullbullbull__ bullbullbullbullbullbullbullbull lt10bullbullbull _ tillO llitO406__ bullbull __ bullbull __ bull __ __ lt10_ Utl2 fon591_ fo__ bull liGa oOa 406bullbull _ __ lt10bullbullbull_ li5S OM
j Ph( vnluls in Uw Inst COIUIIlIl indieatp thnt gunyulp fesinous (IIHlnt( wlwtlwr dfircl hi Yn(tlLJ1l1 wilh L~ perc(nt loss of volntllt wutl pr or tWl c1rild giVPd npproxil1lnh1ly t Iw snllw colorinwtCr rNHiing- 011 till busis of aliquot~ cOlllniuiug 2 IJI~ of flsillS lXIHlntp l)tIf 25-mI volultl( Ihil- illdicate~ thl11 Uw UITW IJ1flS~ of olnshytile mntl(f prt~(iJlitnt(d gins npproxilllntlly Uw $1II1l (oiOfirnl1tlf ftudiTlJs ns tho ftsidtw A pnlill1jllaf~middot (XIlltrinllnt indicutls thlli th VUllltill muller l(lIlSists of thl Ilrplne oil fmcl ion I5-(1Il gtnplls or rlsitlOtlS (lxudntll gnvll by stPll1U distillation nn Uefllgl of 011111 of jl(lfPlIW oil with npproximHte tilllsity (If OHIi lind lhus rrprlsll1ll( IlPIJroximllt(I~ 01 Jerccllt Of t he original weight 1hls lllrClnlage complrcs wllh 38 llltrC(ntlost by drvinI( in IICllnllJ
aSplusmnUH perceilt or orlginlll weightlosl
The wailnble illfolJllntioll on tlH (ow-JitlPllts of the gunYllle r(~shyillOllS exudate alld tl1( HeetOlIP ext act of gaylp ti~slw is sllIllmarized in this paragraph lYalttI (u) alld also Hangcn-Slllit lind his coworkshyers 16 reported that 20 percent of the resinolls exudate from gUltyulc stems is parthenyl cinnamaie (CHuOH=CHC020 11JI2r) Steam disshy
15 (OIlIJIIIIUicatioll flom A T Haai(II~l11it llId (0011(11 Calif0111 ill Tnfiitnte of Tccllllology Past(IlIJI Jhps( wOlken al Htud~ing the COTlHlitlllllts of the acetone extract and other conlltituellis of guuyule
30 TECHNICAL BULLETIN 920 U S DEPT OF AGRICULTURE
tillation of similar resinous exudate in the writers laborntory has yielded approximately 4 percent of the whole as the telmiddotpene oir fracshytion Haagen-Smit and his eoorktrs nportec1 thttt about 25 percent of the acetone extract from guayule branches is parthenyl cinnamate and 6 percent of the bark (ltortpamp-phlotm) extraet is parthenyl cinshynamate These workers fm-thcI reported that 25 lwletnt of the nc(shytone extract frolll bLllllches is a compound with the tlI1pilicaL formula CBoH400a 1 percent is a compound llwltillg at 2P to 2T5deg C and 1 percent of the extract from the ]eav(s is tl (olllpoulld nwlting at 100
to 1710 1Valtei (6) reported that 3 to -l perc(nt of the tI(eton( txtract
of leaves and flowering StPIllS of guayulc eonsists of waxlike substances soluble in olgallic soln~nts but insoluble in at(l and (on(ent1llted H 2S04 The flactions mentioned on the basis of (onHLTutle esti shymates of amoullts actually isolated tlecoullted for about H ptIcent of the totalncetollt~ so]ubles extracttd from tll( guuYllle 11 rub The other constituents ltlilaill to be i(](ntifi(d
RUBBER AND RESINS CALIBHATION CVHES
Typical culibndioll Clllves iol Iuhbpl and I(sins bas(d 011 (ldtLminttshytions made nccoLdillg to the plocCdmC outlin(d 011 pages middotb to 1G arc shown in figulPS 5 and 1+ The spCdlopliotoll1lttL en (OIOIjlllctCI readings are plottCd on s(lIlilogalitllllliC pappi ag-ail1st (Il 11IbblI (011shy
100 ~ 90
80 ~ 70 ~
z 1amp1 0 II 1amp1 IL
1amp1 0 Z
60
50
40 ~ltI 30 ~ en z ~ ltI II ~ 20 C) ~ oJ
10 o 2 3 4 5 6 7 8 9 10
RU8BER IN 25-ML VOLUME (MG)
bull
bull
bull FI(lURE 14--Ctlihration curve fotmiddot gllftYlIlc lubb01 (Hct(lings Oil COIPIIHlII tlOl1hl(
monochromator SlCClrophotolllet(r with 7fiO-11IL Illtel alld Hllp Wll ( IHlll()
bull
bull
bull
RAPID PHOTOMETRIC DETE~MINATION OF RUBBER AND RESINS 3]
centrations From a casual inspection of these CUlTes it would appeltr that Beers law does not hold Actual tests indicitted that Beers law was applicable only within a narrow range in the upper portion of the curves The analyticlil results on the basis of photornetric readings nre therefore calculated by direct reference to calibration curves or from reference tables of equivalent values bllscd on the cnlibllltion curves
Calibration curves for kok-saghyz alld heyea lI11tulltl rubbers and Buna S (GR-S Chem Gum IV Goodyear) and butyl (GR-I Standshyard Oil Co Protoc) sYJlthetic rubbers are hOWllil1 figure 15 The samples of kok-saghyz rubber were furnished by the Diyision of Rubshy
100
90 ~I) ()
z 0
1amp1 a
~ a
80
70
60
s 1amp1 ~ ~ 0 ~ KOj-SAGHYZ 0 l Il
50
HEVEA~ ~
40
100
90
~ 0 80z Q 70a Co)
a 60 ~ 0 0 x 50Il
40 ~----~~----~------~------~------~--~ o 2 3 4 5
RUBBER IN 25-ML VOLUME(MG)
FmUIlE 15-CaJiblation curves fOl kok-snghyz h(YCII Bunn S lind butyl rubb~ls (Readings on gy((yn photoelectric colorimeter with i20-lIIp filtpl and 6-ml aperture)
32 TECHNICAl BUIJLETIN [)20) 1 S DEP1 OF AGrnCUIlfURE
Iwt Plant JIl(I~t ignlioll of thi BlII(un and (1( l))(parcd according to 11( SPltI1((-Culd (]] (6) PIO(((lllll Hlpt pal( CLPPe was (xtmch(L with acetone blI()Ieit W 1I(gt(11l a ttnlldal(l
SEXSlllVllY Ol~ llETJIonS
By lip pIO((l(II11P olltlillP(l 011 ]Hlg( +n Iowa (lOOl IIIg (11 1111i(l0shygmm (gHlllllla) of 1hblI ill a 2)1111 yoltll1ll (all )(gt dltpltld Oil tltl Col(man (lohlP mOIlWhlOl1lHlOl l-I)((t 101 l1lOt 0111 ci( I ill1ilnlly 001 mg of Iublwr ill a 2J-1ll1 n]ulllP Illay bl Ilad Oil till EnI)1I photoshyllectlie (O]oLillllt(I Thll ya lllll- 011 tilt IHl-i- (J I (xl ad iOI1 fmlll 02 gill of til-lI tH(JI(lillg to tllP -lllndal(l jll()(pdull 1(PIPStlIt IlO()2J tlnd 002) P(IT(lIt of llIbl1ll IPI)(((inly bull1t1lollgh -lI1t low allils can be d((d(middot(1 il lIoullt1 Ill IPtllizpd thnt till PIIOl ill PlI(Plltng( or tll( al110unt dltlIllIilll(J i ltlatlpl high ill tili PIY lo Itlllgl 111 aetllllllladie(middot Ill( lopl lillliL 111)(1(1 lIw (ollllil ions of tlil ]lI()(lltlIIIl u ol1tlinpd ipt at l11 11I1 or 1111gt11(1 illt i-1ll1 Ollllll IlPIPltPlltillg 01 p(gtl(pnt of JllUiJtL un tlll 1Hli or (xlla ion rlOI11 II rlll of tisSIll
EIlIlOH COSIIlIHIIO
In Oldpl to H(IIp ill )1lHtPltt pl((iioll illlpIi1I- it i lH((SSHI to slnlldHIdiz(i rigidly 111( Pl()((dlll( 0 illdi(ntpd Oil pnglt- - to J( If lids i dOlH tlip lXIHlinwnlal PIIll is t(middotdllld 10 n ndninlllill
Illlt pl(iioll of (hI ]lIPPllt 1IHllwd Oil til basi of ]llllP llIllJt1 alld Ipsinssollltions call hI jlldgl(J 110111 figllll Hi lileh lio- til HPIlIgl d(intioll oft -illgIP lI1lnSIlIlIIIlnt in lHi((lltagl of Ill( alllOllllt 01 Illhshy1)() 01 lpsins d((PI1I1 iJlld TIl( (1101 PlI(Plltaglt H1( gi (1 101 OJ) to
RUBBER IN 25-ML VOLUMEMG) 004 01 02 03 04
i= I I IZCtOW
fbA ICtU CtCt WW a
01 02 03 04 05 06 07 08 09 100 = RUBBER (PERCENT)
RUBBER IN 25-ML VOLUME (MG) 10 20 30
~ I CtZ
bBOw Ctu CtCt Ww o I~
010 50 100 150 200 250 RUBBER (PERCENT)
RESINS IN 25-ML VOLUME(MG) 10__ __3-0_ 40 50 60 70 60 90 100--_-- 2_-0
Ct~ -r- 1 I OZ
WCt UCt b C wCtW
a o I I 150 250
RESINS (PERCENT) o 10 50 100 200
bllI 1tI W-Yllnl dtd1 ioll I I 11l1 11IlI11 1(111(11 1 III Plll- IlIIIlol1 01 IIim~
bull
bull
bull solution Il basis J o golH of tiSSII (JlILCl-nt (11(11) for (~I) (l)1 til O 1I1
of luhllpl lin 1 III I (I Ill of lUhlJPl nllll laquo I J to 111 nlg of IlSlllgt (Itllillgs on ]iYllyu pllolwh-llrk CO[IJlilll(-(PI with nOHIP Iiltlr lIntl U-lIll allcrture)
RAPID PHOTOlJElRIC DELEHlllNAllON Cn HUBBER AND H1~SINS 33
10 mg of rubber anel1 to 10 mg of resins in a gJ-m1 yolumC For
bull
bull
bull
comparative ptuposes the leslllts arc also calculated on the basis oJvershycentage rubber OL tltsills in 02 gllI of tissul As WOlllL be expcet(d the error increases sOIlHgthlf for 1(lali nmiddotly low COlHell t1llf iOlls oj rllbbeL or resins The curves in figure 1(j s1l0 that ill til(gt Illlge Ol to 10 pCrshyeent of lubber the elTOI rangts Jroll1 abollt Ll to II) ]IlC(lIt abo(~ this mlllc tIlt (ITOl d(((ts(s to (ollsidlItbly ltmiddotss (han 1 1lICPllt of tlH mllollnt ltl((Lmill(d Hil1lilally in tlH (lISl of l(sins analysis (fig 10) the ltLTor is (onsit1eIubly INS than 1 PlLllnt ill (he lallgp of 11 t~) ~() penPII t
In nil ([lSl of lllhblI alld (sins lx(Inltpd tIOIl1 (issups Ol addcltl to tisslle lxtlads (s(( tabhmiddots (i H) illyolillg ll01P o(lllntiolls the eLI01
is hig]wl thun that indilHtld in figllll ((j Im pUIl Ill )])p I tllllllsins solutlOII
COlllUCIIOXFOH IXSOLl-IlLl~ Ilgsqgt(Jg
111 th( Jllo(pdulP ollllillPd 011 paw I till illsolllhll isSII Ipidll( tflpl (xttlw(ioll is (Ptill tlw lIask l(lll till xtlct i l1wdp up to yoltlllH It is not rOllPllipnt (0 IPt()PI qWlIltitati(Ir III(lw[olH a 11(1 pllooll extlnlfs of guuyull I is-lll alll thl1l main t11l111 up (0 YOIUllllmiddot bpCaUHI sllch all additiollal stltp wottld]) tillll-C(JllS11ll1illg Th( Iogiea nll(gtIshynntin is to mnkp tltl lXtlUCt Llld Ipsidup lip to OllillH in till original flask andi llPSStllY 10 llwlno tl OIIpdioll wlHIl (allIlnting [hc llshy
Hults f(JI [hl oll111lC displupd hy till ins()lllbh llsidll( III it l)picat (IXpednHllt (ollsisting of Jhp lppJiea(iolls if was Iollnd llftt at ~iiO ( 02 gill 01 Iuhhll pillS IPill-fl(( lisslI(gt (lollpdll fot llwistUlC ou basis of dlyillp ut lOW 101 ) llOlll-j (lbp(ld only t~ llllUll voiul11P of OOk7D~- OO(lOO(i Ill of lllthyl bolnl(yl 1lIOll( (lplhlli(al-t(Tnltle sp gl () Ii I ll(Hli (j at ~)) -gtitllP tl1(gt 1It101111( () r t is-lIl xt Iadld j sl1lall til( PlIOI dul to Ill(gt insoll1blp Ip~idll is slllall III [0111 ill( wOtk it (all lJp diIpgal(ll(l
]hcon~lIY OF HllIllgl AiO HESIS AIH)gl) TO EXTlIACI OP
GlYlLE TISSlg
Tnl)ll G L(IHpslntillp (ypi(nl llld(~ SllOS (hat all a plngl of HIOK PlI((nt ot lltl pltl( Ilhl)(l acldpd to tllP Itll h iolJut1 InmiddottcJllP xhnet
of guayulp tiSI1( WllS 1l((PllIl Tlli nllintioll flOlll (olllplpU I((OYshy
PIY i within flll pxp(IiIlHuttllIIOI ~illli]llly fnbll Ii llows thn 1111 llYlIUgl of 1O(1~ ])(I(Pllt of gllllYllII 1(-i1l- add(d to II( (pllosol( (xshytrae of IUllY]l t i~HI Is 1l(oPIPI
THl~ (~ Hf (Off Ill of 1111)( J OJ I~il~ lItfI(( In ~(JI1IJk~ Ilf (111 [lI1Il fI2 lIII
0 tlUfllllit i~~I1
Instrument
---- ----~---- bull shy 1(1
Colemun ruono~ltrOUlllt()r 2t) II sJl~ctroJlhOL()lIIeter with 2tJ I iflllllI wnclength Fetting 21 II nntl 0-1111 WU HI hUJl(L _ L U
Ill 7Evolyn photo~lcclrie (olor JU [ imctcr with iO-llIl filler IV (I
H1 0 t I I
llImiddot lUn WII 1011 HIO Wn mil lUulon
10 JIg1111 IUI ml lUl anh Io aLn 111)_I ) III li lU It 2) deg wn2SU DD
Irl JIll II IIr II US II
1110(1 lULa lUI IlK) IJ WU
I( llI Htl tNI 1(111 2tlNI HI 0 221) lllil t2S 0 1~ 10 1~13
In (I 2117 I
10U 1l(J ~ 4 _H_j ___
9middotJIlJ5 10115 10 00 lUU5 flUU 4li (tl03 9(11)
leIlKl 1l~)5 lOOU l1KIr JOIS un 003 OIl Ii
34 lECHNlCAL BULLErIN 920 U S DEPT OF AGRICULlURE
COMPARISON OF PHOTOMETRIC A1D MODJIoIED SPENCE-CALDWfLL METHODS OF RUBBER ANALYSIS
Guayule samples were analyzed by the photQ111etIic method and by bull the modified Spenc(gt-Cnldwell mcthod The values in table 7 represhyselltativ(I of typical results indieate It -atisfactory dcglpe of conformshyjty between the two methods in thl range of tiSSlHH with llHHC than OJ) percent of rubbtImiddot On the bnsis of the amounts determimd the results in this runge for the plmiddotts(nt lIlcthod ayernge apploxinHltely j percent highcr
~LAIII~ 7-(oIllJl(i~on of lltlllrIic (IIri mOtllinl SJl(II(r-(ulri-wall IIIrtlwrl~ of rlrrlIIillillfl 11)1)(1 COIIrll of UI(III
1 Flowers frllm amiddotmonth-oltl nursery plants
YAIIIATJO- OF SIli(LE DETEnt1NATIONS Fnoll TnEIIllIEAN
Rllbbel (Uall8i8-Thc plcCision of thc pLcsent method when gunyule tissues Hr( nnnlyz((1 for rubber may be j udg(d flom I Ill datil presentcd in table H TIl(se dahl -how that thl pplCPlltag( uriation of single determinatiom from nwan yullles with low standllrd enolS ranges from less than 1 to 4 p(gtrlent
R(8in~ wWlsi-r-s lndi(a((1 011 page ~j he INntlts s((uled hy the present phoolllttric nsins llHt hod are not tliltly (olllpalable with those of the grtLVimetri( ncetol1l-cxtlt1(tioll II1etho(l Thjs made it necesSllry to selc(t another lalibllltion staudud-tlll Ipsinous exullate from gullyule shrub-thut gies relatively COllstlllt photometric readshyings (table 5) The resin (olltents of guayule roots branchcs or leavcs usually ran(~e from about) to 1-1middot pelcellt The ple(ision of the present methotf WhCll gUHyule thslllS lIe analyzed for reins may be judged from the datalHmiddotpscllted ill table 9 1h(se data show that the p(lcelltage variatiun of sillgle lhmiddott(Lminntions iLO11 meun ynlnes with low standard NTOrs rangcs from about 05 to 4 percent
bull
bull
bull
bull
bull
RAPID PHOTOMETHIC DElEruIINAlION OJ RUBBEH AND HESINS 35
IAIILE 8-luriation inclieute rubller (mallSM of [1wIIle tissue bll thc 1111O0Illclc metwII
Vnrlntlon~Ilbher I (rom mean
ierCtnl Percelll ~OU -22 ~ 25 +27 ~ 20 +18 ~UO -22---------1_______ 51110 0G6 bullbullbullbullbullbull _bullbull
10 ro ----=ii41075 -01 1000 +11 1010 +13
rlln HI itil 1l9~ 1_ ___ =-~~~
115511 ~ US -111 III II 1575 -13 115 b tiS -I a 111 h WlU +22IIM-(middot bull 11K -1Ja Illi c 1000 +03 1J5H1 W +l)7 ll1imiddot tl 1575 -13
Mcnn 15951 131
1102-11 21fJ() +21l102-h _ ~~)SO -17 1102-c bullbull 21CO +21n02middotd ~OIiO -26
2 r~plusmn Il~ 21151 261 I -~-------bull---__ _~~_~______l-___--_
1 lhe$ 1111($ I1n (or SlIlIIllltS Stpnnltplr PHrilClld IIrtlrdlng 10 1hr prollIlIlr( OIiIIiIl(o(I on Imgt$ 4 to IC ~tcond nUlI1 hlr r(J)[ltnts stl1ndnnl llrrot of tilt 1I1(1111
1_1l1~ n-J(lri(iot in relli(Upound rpoundsins (lllalIsfs of VIOJII( lixsue b1 the lhomillric lII(lloli
-- ---~--- - __-------- shybull I I I I Varlgttton
_________~___ ~~lu_n_Jl_Q_~~~_____ ______I__~_o~S_J frOID lDean
Percent Percentgt458-1 ~65 +41IWtl-li 130 -a2Hli8c aliO +26S41i8-d bull 130 -32
1(-011 34I10Olifgt __ bullbull __ ~--====
li-9~2n 881) -06 li-9~2-b Si5 o ~HH2middot(middot S i5 -6$-H2middotd 000 +1
8851 054
O i5 +6 9 i5 +6 950 -20 U75 +6
H-liG3o-n bull -1 n-li6~b bull __ _ -IH-IWH +4H-l61511 bull -1
1tmiddottlU
62~-lI __ 62~-b ij24-( bull OH-Ji
(-Ull
I rll(St oluls nre tor separately ~xlrflCled SllllllllCS IlctOrdlug lO procedure outllned ou pages 4 to 10 i Secoud number r~prtgeulS stulldMd error of lIe menn
36 TECHNICAL BULLETIN 920 t ~ DEPT OF A(]RICCLTCRE
ReUUER A~ALYSrS I~ CRCOE-RcuUER PROOCCTS
Sew rapid photometric m(lthod~fol the ddellllinttion of rubber and reii Hi ill uaYllp ti--ut htp lllell pIPHnl pd oil pag( ~l to In A brief H1111111tlY of It similar rnpid llHthod fm 1I1hb~rllnltlysis of u1lulcanizNl tlIldp lubbll pl(Hlmtlt whielt i~ bn-(tldo on the prill o
ciples dehtilcd tlllLe follows Duplltate nt-gm sllmph of the finely cliyiliNl IlInttlitiup wlirllll out [~ei-()l (all hl lIf((tinmiddotjv INd to lt1iyidl till alllpl) TIll kltolll-olubll portion of till )111(11( tlrc di-olved a- indh-Htpd fot thmiddot lllnkill~ of -tlllHlunlluhhll olutiou Oil Pt 1II hut tIl IUlIp Hn lIn l-fplImiddotd 10 lHI-ml rolllllltti( fln-k antil1ltld(lup to Olllll1l The bnlulUp or till JllO(ldllll i- thatutlilllll on paWs -1- 1 IHI Ii 111( 1(111 1- nIP IXPIP--pd nil til IHi or Iw oligiJla w(lullt of I Ill (I11l1p-I1l11Ilt1 1)(0(11(1
Hupitl PlllimiPJojgtiWllllllllh llIltllOd~ fOJ Ihl llPtlmiddotminntion of ImiddotUlJbll tlnd 1(-illo- ill -111111 Illllph of gutlYllll tiUl IIll dl-eli)ed 111() IlltlY d~o Ill nltlI1lld fOl III Iwl Illhlwl- and l~iJlmiddotb(lLiJlg plant TIllt l[Olllhup hns nlo b(l1l ntuptpl fot IIH lltlIll1illtltioll of lllhbpl ill 11lHhrublwl Pl(Jdlld~ HIIl 1111 hI ndaptld JoJ IIll ann lysis of ynt1J(gt( ic lllbbl[- The llllthmb HIP 1gtn(11 fill tIll fol1owill plimiph- III Grinding
tIll PIOPlly driPl t i~lIl 01 Ul tillg tIll pnHhHt to tll l((lllilllllh~lel of filWlH-- til plllllit qIHlIllilnth( lXIIHtioll 01 IIlbhlI 01 1(--IJl- () llsing oXWllutld olnuh (kttoJls IIt(talp and() fllltil for LIbbel and IH(ltIlIlyptIJllIllIoolYlnJld-o flJllh 101 niJlsl with t(lathelr high IlPililig points 111 to n C) l]olle or in mixt tIll thllt Pll mit tlll rnphllxututioll of luhll(l OJ [middot(ill ill ~() to (l mi1lutp It r(latiwly high 1lllIllllltlltP Ill to 1~11 ) l) lllllipitntillu till luhblI OL Imiddot(ill frolll aliquot () f till oltn ion I IlIlllI-i () f Hlltabhmiddot pl(~(i]litallt (willifhmiddotd lthmwl fOl IIlhlHI Hild llitlifild lllr fOJ JP-illl t~) IIlHkillphotollllliilPIIIIiIlof PlllPlltal of liht tLaIlS mittUl(P lIftlI IlIlbll (II Il in PIlipitalioll 11 II WI( Iplllh thnt (limiJlall till PIIOl dill 10 xtralllOlh (0101 (till dptl1minntinll Iph jill 011 tIll dtwlopllIlJIl of H HIli rOI1ll tlllbidity 111 hpl than I (olot rI
jJlIlpOP-ofallnlyi-I ( p(lllil1thb IIllijOI1ll turbidity or 1llt[lIinmiddotd d(ltl of jgtIp(ii(JlI l)~ lIltlkillU tIl plllltollllmiddottri( ntdillU al tandinu tiJlH~ (dlllilll wlli(h IhlllH(lill-- IP 1llutinmiddotly tnhll) t1ll1t an hlsl~1 oil the (oJlItlIlllItion of IIlhlHI Ill I(ill (lIPIipitat((L
TIll -I(p ill till jll()(Plhul HIP 1-- follOylt (1) 1l~UIIL uJ1lplls of thwl UJfJlllHl (II tliddl(l HUt dlipd 11Illtplial an lXIllltel with11 Ill of till nlnll ill t (oU tlllltIPlll[gtPImiddotatlup oil Iath at 11 Cbull fol 11 minutl I) iIP1lIin(middot(lohd til( (XUtllhllll Jltldl lip to It middotml ynlmlll til( (nlifild by (Illlifllgiuu HlId thlPl IlI nliql1ot of tIl (IalioPlllxUlltl nll Uillltlmiddotll(t to l-llll OIlIIlIllril fiuk- (1) For a trial Ilnditlg 0111 III tlll j liJmiddot~t IllHII IIjI to Ohlllll with lilt Pll shy(ilitnnl a 1(11 it 111 (Dod fill llli lIut ( ptotoJIIltlil IPtlllillg-- of pllllntnl or liuht tlUtllIlillal(I oil n (lpel OphotnJlllllI at rase hng-tlt (If 11 llJ Ill Ol It lollllil1lPtImiddott lloyidld with tIll P10]11 I 1110110shy
Ihlolllltt hmiddot Ii1llI Olllhi lIatioll for -1IpItillg UJlproXilll1l tply Wtl P ]Plwth )0 mp are HHlltk TIll Illldillg lliJtaillld fol tIlt 4-milutl tliall(~ll-
bull
bull
bull
RAPID PHOTO~IETRIC DETERIINATIOX OF R(BBER AXD RESINS 37
ing are referred to a table of equhmiddottllut~ previously p1(pa1elt1 on the
bull basis of 4-minute reac1inJ~ for tilE nmge of lot1telltlatiol1- of rubber or resins to bE elHOlll1t(led tmd gidn thtmiddot -tnnlillfr tillIP fill rUbbEt or resins aiter prE(ipitlltiol1 lwfolE photoIllNliI j(tltlill1 un IUade The r(middotnmining dllplllatt aliquot lll then HHllil up te ol1l1Jle and lpoundadillg ale marle ut the -tandillfr tiUlE iudklltll ill rhl tall1lmiddot for the final r(adillg~ -1) 111( milli1lnm or p(tCPlltllt- of lllhbpL (II 1(-in pr(s(nt are rpadholU a prlpan(l table of lquiltlput for tlll photoshymetric readings h1~l(l ill pnell e1-E on pxpPlilmlItal lhln 1111(1 u-ing as stimtlltlds pure luhbll in 1l1bbtl milllYb aIHI guaYllh ll-ill- lxIHlatt~ in resins detNIl1111lttion I
LlTERATlRE CLTED
(1) lUnSbull 1fl36 THE mURMIXTIOS IIF IOTA RE I III OOl THER llT~II
F1 bullrol IlY U(T1l0fll UfSlfi ~rrnrl r flm lt1 KEYS TI Bill Chern 114 44J-l59 illns
t1 ~ICPHHlObullbull T 1J3bull~ lUTHOO roa THE PtRInCAnu Or a(lIUl IRrIlHU It of TIn
PLRIHEU Htllllflt [ i Bill lallllall 111 Rmiddot 711middotj iIlus
I ) RHBERG P B Ul5 A METHIlO Or ~u(ronrll-nl Hi tIII rUIl[1 f71 ii illlI
bull 14 Hoss W flbull and HARDESTY J O
llH IR1ltDII Of HfITilIZfmiddotR DllIJS ltt 1 Yl fll Off gI bern JIIIlI i ~middotmiddotlf IIl
101 SPEltCE D nnd CuoWELr ~I L 1933 DETER~n-ATIOo OF RtBBER Ii nrllllpoundRBfR Iusr 1uI II1 amI
Em~ifl cttIliIa~~ r Ell i 71middot7i l11 (HI WALTER E D
1U44 ISO~nlS OF PRTlltSrr 1trHpoundV bull l UI n W lHHt (Tnmiddot 1ETS FROM GiYI l~iIl lItr Clttrn SII J UI titJ middotn9--C1 ilIu
17 J YOEbullbullr H lO~( roLORIlETRT 771 IPmiddot nl -W Yurk f H Plrwptric hmica
naly-II rimttry lUll XphHHlnmiddot~ y 1 1
11
HI) ~ fPHELolzTRf 57 111bull Lin xw Yk t H lt PhmeHt CblUlmiddot ila AnaiY~l~-(H lithrry and XIhmiddotILpfIY Y wirh enomiddot rrJlllrjr hy H KtlJnJU11 I
t~1I --- and ~ARVER L 1f41 nlua-w ~in L liLhr IS IP ll~ XIW Yrk
bull For-sale by th~ ~a~fr1nt~nf1ent Dt~c~~ogtnts-~ s t1i rArnn~ut Pn~~~ tJffieshy
Washington 5 D C bull Pl lU ~nts
16 lECHNICAL BULLElIN 920) U S DEPT OF AGHICULlUHE
750-111 wave length or renclings n1( mnde on a colorimeter pLoic1eri with the monochromatic filter eOIl)Il1l1tioJl for sllecting the npploxishymate wfLYe ]cngth at 750 1Il~ For routine deterlllinations the Evelyn photoelectric colorinwt(r ployided with aTW-lllJ filteL is IC(0l1111HIHtll
The liquid in hich the preeipitnted lubber uld rcins are susshypended is pOll(d very cHrdully down the ill~idl of th( clette o absorption tube to lLYoilllllC fOLll1ntioll of ail bllbblls Aft( LUbbet find resins preeipitation wlwn the EnLynpho(otkcllie (olo1imetll is used the readings are nmde nft(L thl standing tillll- hOWll in table~ It has been foulld (OIlllliellt to 11lPtipilatl tublwr 01 llsiIlS from the aliquo(s at ~-millute illtlLvals This allows stlilieipnt tillle to check the eOlolimet(r and to makc 111( lNHlings Vlwll a ehangp is IlltHk fLom onc rending 10 the l1lxt it is advisablp 10 llle the clIvctte 01 absorption tube nt lpast twkp with slllall p(Iltion- of the llllltiol to be leitd
After the colorimd(L lluding lta e becll Iltndp till IlIl II igllIlllS of lubbel or resins or thc lpL(el1hlges pnslnt in Ihe aliqllot are r(u1 from cal ibmti(Hl (urVlS (fig~ 4 and raquo or from plepn Led tables of eqllivallBts baecl ill each (liSP on (x[lerimPlltnl data The results are expressed as percentages of dry weight (S hours drying nt 100deg 0) of the original tissue The errol lltle to lCflyjng the insoluble residtH in tbe voltlllletLie pxtLHclioll flflsk wlwn the pxtrnetis being mnde up to YOlllmC is V(ly slight sinlte only (U gm of tissue is used FOLroutine allalyscs lhis ery slight eLlor mny be dislpgnltec1
EXPERIMENTAL RESULTS
The experilllCnlal reslllts Oil hi(lthp method- of tU)lPI and l(sins analysis a le based ttl( d icussld blicfly hlrehl
PHEPMINrlON OF SAlULES
No difliclllty was expPtitI1(ed in pltparing slmplls of llllrscly-glOrt guayule plants 1pss thnn ~ YPH1S old 101 rllbbpl alld IPSills analysis In the cnl of Odll filld-gl()n gllayull plants PIIOtS hopel mtty be introdmp(l by the custOlllalY Jlwrhod 01 pICpalillg Ihp sampl(s 101
HlutlYHis as is lwipfly i n( ita ttd ill th is s((tion Smh enOlS do llot nffCct the ])lCcisioll O[ t1H llwt hotls for LllbbtL n nd Il~in~ nnn I sis i nee till) are due solely to tIl( tbsup--ampling (llo(pdule in thi (a~e of oldeL field-grown plall TIll 1lllt1lOcl of salllplill7 fipld-gl()l1 plants JllOLC than ~ Y(HrS old thenfort Ieqlliles iurtlHl jnttigntioll
lgtAHnOILr~G FOR HEllOVAL OF UUVLgtS
Parboiling which (onisls in boiling gllltyule plants in water [OJ
8 to 1~ ~ninll(s ~s col1llllonl) uSNl a~ n llHans of Itlli rCnl()y~l prior to drymg nnd gllnllng It I~ tHI([())P ll(e~Sllr to ltItLeLnunc all possiblt~ eflct oi tlti PLOtPlllll( )ll (Il( final results Exp(liments have sh(nm that (helt i- fl Flight loss ill til tmiddotjght of lOO(S and 4(ll1S In I typi(ul lXpelillltll hlu1llHs of ~- ii) -1-ytII-old gllllll( pllllb were Italnd at randolll Olll ( of talns wa- paLllOil((1 and the le~es (1( haIHI-pi(kpd [lom till o( hpJ Ht Both pis (1( dlipd for 48 hOttlS at (i) C in a llI((lwlli(al (011((( ion Oyell Th( lpsult are SUI11111I11izNI itS follows
bull
bull
bull
bull
bull
bull
RAPID PHOTOMETRIC DETERMI~ATIO~ OF IfCBBER A~D HESI~S 17
Dry ucilht lust ill lariOilillf
Plaut (pcrcrllO 1 1 -I2 ___________________ _
213 _____bull _____ bull __ _______ ___ ____________ 12 2(
pound(111_ ______________ 1 R
4_______________ _______________ __ _____
A __ bull __ -_
The efred of parboiling on till final lllalp i SUllllllatmiddoti7(middotd ill figmc G Rubb(1 lecoYelY w(t about 1 percent higher for parigtoillltl plants and lEsills re(ovelY somewhat o-er 1 i)(lr(lllt 10Wlr The (Ii tference in lublH-l r((o-elY cannot be ae(01111tltlt1 fot by loss in dry weight _ due is to be found in a study of thE grinding lwhadol of a parboiled and an unpnrboilEcl shrub The grinding of the patboiled shlub in the hnml111 mill is much fadlitated and ns a rule for tissue with a rubber contCnt below 10 peteent llO aggregates of rubber deelop in the 1Il11ehinr during the (Jpelatioll Yitll the unpnrboilNl shrub some dillictdty may 1)( (lxppliellrl(l Sill(( sOllle of till sti(ky ltxlldutl Oil the plant may scI( u nlldei for the fmllHltioll of lublH1 ngglPgates Til is apparently explnins the npparlllt los in ruhbpl frol1l the llnpariJoiled hrllb as eompnlelt1 with thl palboilld (fig (i) TI1(loss in r(sins
II
RUBBER
10 f-
Ishyz LIJ 0 0 LIJ 0
9 --RUBBER -shy-------shy
-- RES INS -shy---shy-----_
IJ) 8 I--Z IJ)
LIJ 0
0 7 f- RES I NS -0 -shy0 LIJ III III J 6 f shy0
LEAVES REMOVED BY PAFltBOILING
5 f shy -shy - BY HAND PICKING
4 I I I 35 30 25 20
SCREENS (SIZE OF OPENINGS IN MM)
FIGlRE Ii EtIe(t IIf pnlticlp sizE Oil lEcorPQ- of rubber lind (iiil1s when lEgttiye wEre remond hr Pl1liloiling lind h~ hand pi(king ((Dlltrol) plllllt1lt groUlld in t hammer mill
6114038-46-3
18 TECHNICAL BULLETIN 920 U S DEPT OF AGRICULTURE
recowry from pUboil(d shrub may be due to the loss of the resinous exnc1ate during parboiling This exudate forms ns It SClim on top of tlw )iquol in the tank
On the basis of t1wse results the recommendation is made not to yaly the nwthoC of leaf lemoYal in any 011( lNi(lu(h project Then fltirly compalabh IcmLts should he obUiined
70 ~------------------------------------------~ LEAVES REMOVED
BY PAR80lLING ____ BY HAND PICKING
60
-I-Z 1amp1 0 50 a 1amp1 a
en 1amp1 gt1amp1
40en gt-CD Q 1amp1 Z
I shy 1amp1 30 a l shyx C)
1amp1 ~ J 20 I shy 0 I shy
10
O+--L__L-~__L-~~--~~~~~ o 10 20 40 60 80 100
NATIONAL BUREAU OF STANDARDS SIEVES (MESH)
FlGntE T-lJiMlil)utiun of l1Ultkh si~(s of gnll~II( tiSSU( JrIOllll(l in a Ball amp 1ew(1 mill to pass six dllIerNlt S(I(euroII 1(IlYes Iemoved from plants by palmiddot boiling 11(1 hand picking ((olltloll dpfo1iatld plants dried to 1I lUoistufl l0I1t~nt (If 01 to o) 1)(ICl1It ground tiSSlli IbalH1 1() minutes ill II ~i$hel
bull
bull
bull Kahn shuk(f
RAPID PROTOMETRIC DETER~UXATIOX OF RrBBER AXD RESIX-i 19
GHl~DIgtiG
bull Th~ entire pant 01 plant l)iHt a~(gt fl r(ll it pllllIIirU1ry lSillg fur J hours ntGi~ C prIOr tD t 1( plChmll1atmiddot rLlmhll III a II lItmiddot or n Ball amp Jewell mill ~n llltllysis of paldch lzP- nftl~l (oar-( IIindill shows that tlwy ar( about tIlt llllH fOl parbojlP(t awl IJllllluhoileu hrubs I fir 7)
The coalilly gloUllll ample i-- thPll Ildlll forI toUtmiddot at ni C afnr which it ha lllilobtllL(gt output of ~ llllut lII hmiddot- dptPlIIlilwltl by drying submlllpil- at 1110 fot hOtll- TIll 1 IIIIll i lltllt lmiddot0l111d hi a IluninHl mill TIll mo(lel uP(t in thi IIIk i 1I Hu IIIOilll mill as IllUllifill bv Hoss nnt Hartlet ( 1 -[1lt111- with n1ll1l1 pldushyrations ittI lilnbhell b rill HanlIolll V0ll11nHiol1 ElIillllmiddotrill (0 The size lutllihl11 iUlJnole So I ( 111m t ~ II t HUIII Xl) ~ I L~ 111m nnd So 4 lillllU1 11 ttllilhmiddotj 0 r tllP Imiddotlult~ p(lln-It willI t11(e Sll((IIiZtS with )arl)Oiltll awl uil)Jtllboiltd hrlll b lOwl1 in fif1l1fmiddot-- This hows t tnt 1middottttIl ~(I 1 llllll (Up jlllilnl IHlt that
r------~-------r--- ~ --r IHAMMER-MILL SCREEN
O~ NO1
NO2 ---shy U NO 3 ---II
I
bull lL
z
r ------ l 30 ~ gt III
i I Imiddot
i ~ I
I 1 I I
~ 20 I - 1 iii 1[ r 10 ~ ~ ~ I _ ~ I r A bullbull
o bull L-~__~__~~__- ~~ 20 40 60 80 100 40 60 80 100 200
NATIONAL BUREAU OF STANDARDS SIEVES (MESH 1
Yutln I i-tlillltiuli Hf pur id lZt f ~naY1l1 t middotnt r1 lI1 i ~ a hatlltlllI 1IIi11 to 1111 Lx IHtllllH middotIn Lt-anmiddot tIlllunl loy la1 litkh~ omrl t 1) tHul parbuih~ -t B ~ thmiddotfuliufptl ]~lahr thpt tu tt fit t 1 It+gtr-tt1 Jnui~tHn eunttlIt _~rnlitl tl~UP ltakmiddot~~ 10 UddU it~ 1 rtmiddot4~pt~middotK1~r ttakt-middot
bull So 1 gingt- 11 tt-liuin-Iy ltr~pl [lPlItl1tat of iilll 11animiddotImiddot- Eqltrimiddot tIlllll hnnmiddot llOWIl dutr fll llltldllllUU xtlutioH 11pound lnhbll lIl lP-ill frolll IolUlIl ~tlaYlllt tl-IlP by dlt IJwtmiddotlUlmiddot lItlilwd oil Ill 14 - 01
i-mllt 11111- -lwltld hi INd I li~ Ii I TIll lllhtIlttj of Itiu~ So 1 (lltll j thnt 11middotmiddot01middot lttwmiddot to amplil tltt Iollllli tilt art lpdnn ib
IntIIll ll~ i po--ihJI with tI lLllit Ilfltl[lll1t It honld l Plllplw izmiddotl rImt ilt tht h of -allllhmiddot with l lllblPl
~ontlnt of ill PPltllt til lIilll it i tlllt pll--ihl 10 11-middot t(1i Xli L
20 TECHNICAL BULLETIN 920 U S DEPT OF AGRICULlURE
Even with screcn No 2 difficult due to rnbbel tlcrltreCtlltiollS may be ob tl
encountered In thes~ caHeH it iH lWit to parboil the shlub fOL leaf lemonll and finally to dry to about 1 to ~ P(l((llt of tnoiibl1(l pound01 b(~t results jn ~rindillp in tlH hanmHl mill
It iH aclvlsable to provic1l thc hammer mill with a ground wire Hillel the presence of static electric (harges 011 tll(middot partkhH will ealls( Home of these to atlhelc to the inside of tllP (olltailWr OJ lila eallsc OI1l( of till pULticl( to form ngg1(llatls EIIolin lalllpling fl01l1 fhis SOI1I(I mlly be (onsi(h1llbl(middot
A1I10l1g the Holnllts with high boiling point that lIlay Ill IlHld in rubber anal)Hs I1IP Illllhyl n-alllyl ketolle methyl ioblltvl kptOIH diisobutyl (tOIH blltyl tHptate llethyl amyl 1Ittail (middotthyl(middotlllmiddot gly(ol diethvl (middotther and n-bntyl (middotthel (labl( 1) TIHse al( also I(sin 01shy
middotent but th( 1(~illS n1( held ill olution by the rll1)bpl pl(l(ipitant tthanol wll(1 lllbb(r is 1)J(lipitatNI (S(ll tabl(s alldmiddotl) On tIle basishyof the lxpHilllPlltH tll( btsf nil-round lolPlli -rol lS in 111( PIlHPllt method is lt1iisobutyl kPtonc wld(h was not IIltlllllfaltllllmiddotd ltIlling Vodd Yflr n A suitable Sl1lgtstit ute iH llHthyl jolllltyL htolt whi(h is l(porhd as llolltoxit UJ)
Clllos()IY(~ (ethykn( glYlol monopthyl (tIH1) blltyl earlgtitol (di(thyl(ll( gly(ol llIollobutyl (ti1(r)~ and acttonylacetOll( may be used as resins sohrCllts (table ] )
In the earlipr work with (sills analysis cpllosoly( alolle was selcmiddotet(d as a suitable solycnt Aitholllh (ell()~oh( alone is pxc(lllnt its rplllshytiwly gwatlL iscosity 1(I(b to bubbl( formation nft(I (SillS pr((ipi tatioll Thi- increased thp (xperimentnl (LTOI OIl of tltp othll I(sins solpnts tI((tollyla((tolH has the proppry of glpatly lNlulingshydH(OSity 11(11 altld(( 10 othr liquids This sohpnt tlHIeforl wa addp( to ((Uosoh( in slIflici(lJlt tlllIonnl to OPI(0111e the dinieulty On the basis (li~ex)le1inwllts ~ purts oi~ a(donyla((tOlll to I puts of (elloshysoh-f (bolll by olume) as Splldcmiddot(l Thp 01 hel Hoh(nl listed hutyl clLlbitol at l(llst the t((hnieal-g1lld( ploduct uSNl is appal(ntly not as good as eithe of t1w ot1(r two () a (ombinatioll of tlWSt
The SOlVllIts JOI liSt in tumlyzing artifkial lubbel$ hy tlw pr(senf method appllLently (lcllIHl on th(middot kind of llI))(I lIp-ityl (Jxidt is suitable Ol BUlla fi and hutyllthlI for butyllllbbl Tlwse reagents IlLe technical g1lld( Calboll amp CtllUil1t Ch(lllilai (OIP This Hllbjp(( hilS not bepn (XtpllHl(ly illwtigated by till WIit(I
PIIECIIIIJ-
All tlst fOl Ih( adlqlJalY or till IHllipitullb ll(Ollllllentillllll11Sl bl baset] on the plctisioll of tllP final I(snlts oiJtairwd with the methods The )redpittlllts s(1e((( n HpJ (xtcllsi( (xp(IimPlltatioll all HatiH~ factor (Hee fig Hi 111lt1 tabItmiddot (jH) Ext(IIin tllts llllTild Ollt hanmiddot shown that H Hatil-gtflltlOIy [gtIpeipitallt 101 1lIbblI is (li-p(IT(middotnt HzHO (c p reagent nil POll sp gl U-lmiddotJ) ill li-P(l(Put (tinmol by vohmlP liol (tllayul( Ipl-gtinl 1l)-P~ITImiddotllt H)~o ill Hl) by ollln( ii lL satishyfaeto7-y l)lp(ipitunt A solution of 1 palt of H~~o to 1 part of H~() (1-1) iI2So1 nnd abo yarious int(lIlIPdiat( proportions of tlllse suhshystanCPs giyp fait 1(511It8 but with till inlIptl(l ill [h(gt ratio of H~S01
~
bull
bull
bull
bull
bull
RAPID PHOTQlIEfRIC DETEMIlXATIOX OF HtBJER AXD RESIXS 21
to H 20 the )olutioll becollles somewhat vbcou5 and precautioll Il1Ult be taken to ttvoid bubble formation When it i5 poured into tilt Cllvettes
It should be lloted that both of these precipitants have an ftellleshymmiddottion It was found that when XHjOH was used in the rubber preshycipitant in pInt of H~~O~ the readings were -table l)Ut were not reshyproJutihk The lIl of XuOH in pInel of H 2SO j ran nHittble result as a llth H(HY(Pl WIWll til( li-P(l put lthatgtl in lublltl llnalysis or H~O illlP-ius anal)j wn-i uddint(1 thl eharalteliti(s of till liquid with pleeipitated ruhber or resiu in HI~P(ll-ioll n ren1 on the lpNmiddottroshyphotometel m tololinlPtprfollop(1 it lPgnlal lIlll II~ lxplaiHd on pHgP-I (Sl( figs 11 aIlIIl) Tid made it lloible to outain lEPJOshydlHibll tpnlt nntI (onplt1J1(Jttly till JpqnitPIl tlPgJPP of PJPcljoll
IIWIE(TI 1lt COl~101J)
Jtl thp ItJiPl middotxlwlillltnb hefoJ thtmiddot -1l]YIlIt allll pnmiddotdpitallb had lIptll ptoppJly adjutp(l it l fOllll tIuH till llP or a Ploltiw colloid -wll ltIi1)cJ [ttlJmiddotntl- imlIopl tll lmiddotpro]lIibility of the lPlllt JmUkllly ()Ilt 111 U lput lUlU illlihumiddot tOJllPOlUtl tpHd liglyeol teltlut( - llpanlItly IllmiddotlfP(] to lit til I1m t IHflll lImnnmiddott nftlr tlH filial prOIptlllll WtlP dlvPllill1 tlll 11lIlpfit (If thtmiddot [llltlltin lollohl wa Hot 0 natlv I1l(lhmiddotd III rlumiddot Ia- of tmiddot ill tllmiddottJmillaritlu it b [1 hmiddotjlmiddot til IIpoundgt Ir llH1 It liltr ill-llImiddottiT Ina lll ptlPII by it U( in ruhhfl mmly j 11If dtmiddottail fOJ tltt lllllmtlllll If thl plot pet in nlloid ~llntill tltlmiddotlImiddotmiddotlttlatiflll lIOlllllllhtiPI1 are iPllllll page
liTFHFEHliG COIOf
(hi II tht lllail 11111111111 that had til ill -111111 II urklll) om tlH method fot lublJtt tlIlO1 rpir- nlalv~i in plaut llllpll- wa ttl (lilll~ inare tIte (gt1[01 till to tIll ptP-PlHt f xi [aIWIIII- 111 TIlt amount of (olor varip from lUllIt tn -amp ]pplwHlI nlt rhmiddot lt IIf thE Hl(ltllial tllP part of till plllIt -lI11lhmiddot(l tilt hi-tlllY f tlll plaut mtteshyrial ~ub-lltInent to Itlllmiddotnmiddot-rill lliI 1011middotly OrllPI Inlw
In ruhlwr lrtl-i I Iii 1101 au Itmiddot 1Iplll11l by 111[ I--r ratmiddottilt thE -lllll]t with uptoIw or 1middotmiddotlIll-ol - wIdell [llllol- rlll loillriu nutttel autI thtmiddot lpill- Thi- howmiddotvt n(tnll- til lXtla -11gt1 ilt prlJ~edun) In lP-ill ltluay-i nllHufldy tlW[t j 11 1 1IO(PIlln fill the 11shylImya of hlulophyll Hwl rIlI-r middotIOII IHlttlmiddotJ dlH lUtl~ In plltIH withoUt alo aiftIriL till nmiddot ulttrll
111 pllIbIll1l Wi tilmiddotr hId h It-ImiddottHI tht Pltlpll 1 hlitlt lilt tlw tulllWlli tollImiddot uIwltllIIntut -lltUIhorlllllltll 1111 tIll tlettlllliIttwr IIf t 111 lWlrl-Uamiddot of bdt tl11blLlittUhmiddot r [1 tItmiddot preshyj
lipitatifll 1lJ llllllWI atbull 1iI- in III -1nrmiddottIi fHlttalldh nlrillU~ amount rf middotlorilig lIUlttll Iii lhll of ih lltmiddottllllhottohttt~l l~ol()r infrtl Hm II upd 1 rwmiddot tld~middottilmiddottll PlllItlhi~ f it j proYitiltl with tIll lilP--UlY tU(jlIdlllIlml tIltmiddotmiddot lllklllUIlI
EIECTIol OF 1 [EGTH~
-Ptfmiddott ral tracilull ru~lI gtIll fr 1 nllb t ~xtltd 1 lIlt-th vI iobmy1 ketommiddot lWtl rill [ Ixt lttltt ll UttollylaIiIitt1l11I1t~ ~-I itoiu YtHil)u~ typp of ~IHaylllt f i lItmiddot art hraquoil ill fio1ll1 ~l Th~ lp-nlt fill I11oohl uio[1t ttl willlr til tltN- fur rht IUiXtIUt iwliutll
100
22 TECHNICAL BULLErIN 920 U S DEP1
90 bull eo
I shyz 70LLI 0 a LLI a 60
LLI 0 50 z
a ENTIRE 2-MONTH-OLD PLANTS~ 40 b ROOTS AND BRANCHES OF ~ 3-TO 4-YEAR-OLD PLANTSen z WITH LEAVES REMOVED ex 30 a C CURRENT-SEASON GROWTH OF l- )-TO 4-YEAR-OLD PLANTS
20 WITH LEAVES REMOVED
d LEAVES FROM 3-TO 4-VEAR-OLD PLANTS
10 A
0
a Cd 100
b bull
10
80
I-Z 70LLI 0 a LLI 60a
LLI 0 50 z ex I shy 40 ~ en z ltI 30 a I shy
20
10 B
o~__~__~__~~--~--~--~--~----~--~--~ bull350 400 450 500 550 600 650 700 750 BOO 850
WAVE LENGTH lM~)
FJGcm O-Sll((middotlllll tramaniW1IHl (mrpS f(JI (xlmll 11011 n J1ll of jlta)nle tissur ill n 2--m1 Y011111P of (A) Illrthyl ji1I1J1ltsl krtonp 1111(1 (ll) nt(middottQnyla(umiddot tClIc-C(l1osuln a-i
bull
bull
bull
RAPID PHOTOlIElRIC DETEH-UXATroX OF ntBHEIl AXD HEstxs 23
ThE dula Pl(S(l1t(lltl indi(ntp Ihut 101 Illp ulimls llHthyl liohutyl htOlIl (lxtrHts (lI(I r(dolls of Il1Hxi11111III nigtol]gttioll wiH1I all (is-lIb 11 cOllsic1(]((l n1( blhn(11 wn ( ItIl( Its lIO to () I1It~ nlid Ii to Iii mJL
WhllNIS tlw I(gions of 1middottnL(s( light 1lnlllittamp al(l lgtPlW(PIl wan Ipllgtltsnr) to Ii nllt jW) 1I1JL nlld alio Silllill1l 111l1b (n SI(lIlId 101 nc(ton ]altmiddot(fmiddotollp-(llloolp ~ pxt Ill of 11a 1111 t illl TIl( (1101 du( to lolo ill tlw litlltitl a 1Il1 lullll(I tH lPill- hanmiddot bpllI PI(_ ipitated ma he 1((I1((d to fltI ynbhing poillt II ph( illg OJ illshylmiddotJall(( WIWp balld nhm ()) IIIJ1bullbull[1I111 lxjlPIitllll1b Illln -h()1 that Ih( lIIot uilahl( WHYI lHlIJ fOI 1-1 ill 1l11J1l(I HIH11Pill- illllllrsi i-in till IlPighl)()lllll()(l of ~llIl1lt bull
bull UIlIilHlIy of n typhn] lXPllillllllt to )10 l1iP(tiP ((JIlllo( of (ItOIS dul to lOIOl in 1llblnI Hnd Iill xtnumiddott 11(11 IIIIolp t jUl i p1llelll((l ill tub]lL Till llhlllt- 1tpIO]II Hnd ((llll~()h whit-h UI(I ](]Hllilltl n 1I01lllIhb1 01(111 lxt 11111 IIll 1llll)1 nmtp[in I and )(middotills Tid IIlnkl it poiblp nftlI tlIp uplll1tillll or tlll o1PIl( (0 [niH lip 1Iidl1p~ of lI111 11111(( ill lit ll11l1)[1 (llnlIb nlld Ihll
Sl(ll n ol1lliOI with tllP olnl IJllt illiollt HIl Iltlllll llllI (Ill ltllthpl prpipitnnt j Ihll1 nddld OUI ha a lIilPt lP( of till lIiciPlw of WH( lllIgth 7) lUI- ill llilllillatiu (nnl till tll Ixtll1I101l ()lll~
Tuu tmiddot-Elilll IJl flrldillY 11-1111 lrlllI IjfJI til islII 1 1(1 ([rllt IIIIIJIlIr JiIlIt~ if 1Il( Ihll 111111 k til I III Ilrln I 1Intd tf 11111 JiSf fill I I II I tIII Ilf Iilltl 1f1JlIIillII1f I Till 1[ 1 IId 1 (I (middotIt 11111 (I1I1iI1 1lf1IWtlfJlIIllfflr p middottrllhIJ11 II J III 7IImiddotIa 111 111 lilt jJIp 111 wilTII
t~t tnVIli~ ~nn r kn t~ i tmiddot ~~l Jr 1middotmt ltlTt
HmiddotOtt ~I~ lin t I ~ 1 t~~l ~qrmiddotthtmiddotrtwb
Hult-middottltlru t T Hw ullut rHtt~ r II I ~ PH~lllt
A~tmiddottHHjmiddott~rjd rl ~gtllh 1 tn~th~ ~ ~ middotI lt~ b w bull hmiddotth~ 1i~lIhun 1 Ii tnl Illd1 -11lt1(11i lullI lUI tJl ll~ t1~11n( I Ihan1li flfttIJir Ult I Uuhtltt ahuul l(hmiddottHmiddot~t trv r fti HIt lftbyl tlonhUt)1 k_hIl( 2 m~ fmiddotf tuhlHmiddotr In mlth~ llmiddotlf- 1 t r
t r_~ t j
Arhlitlltd ~llIIDHl NcWitn1 ( Ar-(lt()nc~middotttrrtrt ritJJI~ -Iu nllJtl4-middotr
ACtmiddottflnp fmiddotxtrn( ~ T-P511ftf tn mtmiddotth~ 1 ~difmiddotut~ kdn 2 nltt ulruhhtr in Un-tIl lltbu )J~IYt
rUth(Hl~hltlft HhubU
Illlh(I(t tttUtUt hUbtl til J ~jlitl(J Hilllll trtIIImiddotjtl1ll
(UShl I ~tlO wHllolH rulh r (middot1111$0]( J~rru t t )lthyl 15bullbull1middot1101 klll1l
Ili( UHUicbcul ~((i1rUtl ~ulu1iin 1middot lIUIll Ilti lrllltlllt I Ruhhr llt1thuI r1 -1 Irld
ltlt1111Sh 2 nuz f)rruhl~rm nlith~l tu- h f nt nil~middothgt(H] tlrlftmiddot 9lUtirtl middot1 1
rlcltfl( H(l dnllltml it
(IISllhH~rI( Iultruhtr CII05 1v ltTlft I 2 UI~r ublwr In llldh I hlt~1 11) lgtjdvr(llsl~9rlltmiddot middotlmin ~ I~ gt AIHItilltl no IrttipHallr iI
~ Bbnk 10ol m(thyl i~tmiddotut~i kdHn H 1 m1 j~~ l1rH-t lt~tlfltmiddotn sf n it ll HltlMjftr~nol O2~mlJ ~U~1o-ulp ti~tW -xtra~middotl(lt1 ltt 411 ml bull ie f Ct- kft rt t~ tirattJ middott ill r u l1kn ttJt
in metltl isobutyl kNqnf nn~i mljp ur tmiddotmiddot ~oml ~urr tttl i t w ltJj1JH kt 4t 3 nlank 1 mL((l1t~rthmiddot(middot mI mttr~ ~but a kmiddot tmiddotc d 11 ~ gtli~b~ hifIAft- fl~ lL lnti 149
ml8(dlfilll BO bull 02 gm guayule U$Stl(middot xUlClt-l tf(h tft wI n nmiddotmiddotmiddotlgt 1 lznt on tmiddot ~Jt r~1 ~~u~~ H~ iI~ thT
24 l$CHNlQAL BULLETlN l20l S DJltJPT OF AGHl(CLlOHJltJ
In table a is pl(sentc(l such c1il((t edlt1tIHC showing that thc (0101 Ixtrnetccl from guaYIIle tisslIe wit h II(P(OIl( n nd (pl1oso[yc is cll(div(ly sCIe(nec1 out by the s(lp(tion or wnw length )0 miL Oil t1w SI)((IOshyphotonwtpl This tnb]p all-HI ihos thai thl Juhlwl altl(l((1 (nn IJl quall shytitntivcly 1(I(()(Ipltl in tIlt PI(ilIH( or Ih (o]OIplnwPIials and Illsins and tlmt Iuhb(l WtlS nppnlllltly 1I0t (xtltI(((1 110111 11l glll1I1l lisslIt b~ tlHSP SOhlllts Thls( ((suIts ginmiddot (OliIHillg (idJt(( that t Iw IISI of waYl llngth i)ll 1Il) OIl till SppdTophot OIllltPI ii t hl 1101(1 p(oshy(ellule in photolllliTie IlIlalysis of luhhlI OJ l(sin-
SELEGTIO- OF )IOiOCUHO)IAIIC ItIIm ((1111110
On th( basis of th( IPHIlb shoWIl in tabl(l 1 al hlllpls (1( IIln(lp to SPCtl lC the PIO]Wl 11101lO(lIOl1ln til Ii ltlJ ((lIllIJi nIl ions 10 llIiOlS (oIOlimet(Is 111(gt 7W-Ill~ filtpl flllnhwd 101 til( I1~lI1l photoshyplpct1i( (o]oriJl1ltll fol which Ill( (hlll(IlIiitit~ oj t hl Ilda he light ilUIlBlIIhiSioll (t) elll nn -hO11 ill fig1lle 10 iws satlsfa(lolY IPshysultl 111( iiO-mL HitlI olllhintioll 101 whkh ttp (middotIatinmiddot light tlnnsmission (ullmiddotis a 1-0 showlI ill figllll (I is -nthdnlto1 hut this is not stnlHlnld NtllipmPlli
Up to fhl PlPHllt lIS(middotflll pound11((1 (ulllbinntions jn lltl iOO-I11L Iunge hayc nol bllll SlClIlld 101 lhp Klpt 1-1I1l1I11PISOIl (olOlinwtll bu fnltlwl nttCl1lpti 1( )(illg IlIHd
TJIpound OF ST~lmW AFTEH HIIJ1EII Oil HHSIS rlll~CIIITTI(J
~ considl1ltiol1 of ttp lillll of Inlllling af((1 plpeipital ion of 111gt)(1
01 l(sinSTlOIll ollltionis impoltant J(jl~ thC1HI(Plltngp of light IInIlSshy
11 rshy10 f shy
09 f shy ~750 Mil- DOMINANTI
~ 08 cshy I WAVE LENGTH z
I III III i O7 - I III
~06 - 05 shyw
a
Igti= 04 - 720 Mp DOMINANT ct WAVE LENGTH- ~ 03shy
02 f shy
01 t shy 1)O~~~gt~- J 600 700 800 900
WAVE LENGTH (Mp
bull
bull
bullFIGlRt IO- COJllPIUlItiw ~IW(middottltll tlnIlRlllii-lion (II (IllP( 101 1i11(1 olllhinulloll
with dominllnl Il(lllllgths at 720 and 7iO lUi
bull
bull
bull
HAPlD PHQTQlfE1IUC JjETER~lINATION OF Rnmrm AND HEtiINi 25
mitted (spertrophotoll1eleL lCuding-) Ol light (1 (tClcrl (phOlOshyJluol01l1et(L lcndillg~) i~ StlhjNl to (hangl
]fjt~l1le 11 and l~ show that ill til( (asc ot tJaugtIllitteltllight llJHC th~ (x[llliHlllIlnl (oIHlitiOllS tllpl j lilst n dtlln-e ill Pll~(lltngl or UllllslllittnlH( follrnY(l by It ptJiml of lClntin stability with only sliuht (1111 tHn- a f(Pl a lIt1ll1btJ of minutes The light t UIllllitblllll t l(1 ill(Iln~(s This lIIay IJP llllllJltlli7P(ll1 ffl II ow 1Ilt )( f(( darI oliIII tIIlIlNlIlitt(IIIlfJIIlh (iditilIiid Ilil1 pllIipintnl )uoshyIn Of ( 8inx in (~f1( I~iUII i~ Ild stahl I 11 itlll If 1inl nh prlshyilli(ioll of 11l1d(1 II IJIX f) jllIli II (fJJltfiIIlilty slllMI IIriot 1) IIIPldUnl1i tll(I1I rllltltilJl oj tJi~ Jlt jiot IUN ilUf Jxl1 will tIt( tOWI IItlllilil I 1llIlllblJIol I ill I~11l11111 d ill till ifjuids JjOI scnttplltl light 011 till phololltHJIOIl1lttl till dilPCt ion 01 elangl b tlw IPrfIi (If that illrli(atPll rOl tlulll1Jittp(lliuht It Itlll b( llluliJr I-(Pll that if l(middotndlnJ- IIIP mad n itl I t lIP ~()ll1d()lb lpalll this pllioJ of nmiddotlatirp tuigtility tllP llLot tIOllt thi Olll(P (nil bl IPdUCld to tIl lltini III 11 Ill TIll l~adiltg (illH~ bbll Oil tlHl datn rUl lublwls and llsinlt Illl ginll ill tnhh
50 r----------------------------------------------- f shyZ
~ 40 ~----~W~A~V~E~LE~N~G~T~H~7~5~0~M~P~~~~ ~ --------------------=-=-= ~ 30 f- WAVE LENGTH 540 M~ _z _____ ___ -=- __ _ ~ ------shyt ~_=---=-=--I GUAYULEIII 20 -Z HEVEA ltt II KOK-SAGHYZ f shy
4 6 8 10 12 14 (6 18 20 22 24 26 28 30 STANDING TIME (MINUTES)
FIlirtn 11 Emmiddot of wav hll~rh Il li~ltr tlall~lIIit1alHl aftI IUIlItHt -Imlli lug 111m for guaynh llmiddotn 011111 middotiolIlJh~z 1111111 llijlitul1 flolll 1lHlh~ll1Jllryl k11II11l ~(lilltlll h~ lwitlitll 111Inu1 111l~1It1 2)1111 o1U11111 (Helillins on (illllun tlunhll IlIIJlllw]ntllW111 lutl(I[lholtllllltlt with ijUjt Wlnl IHI Ilf1 I
11 EFFEGT OF Hbli 1 -()JXT10~
Tilt lnblwl ~()h(llh pxtnl( till IPillgt ubo It 1m nllu1- bellt -~atea thut ~lll 11-111- tUP olnbhmiddot ill middottIIlIlOl ~1It tlWIIJI( my U)t PIl (tlIHatcl WIth tl1l lullh(t I tahle lJ 1hln 1- -1111 tIll (llllstlOll of nny p()~iblt tITptt of XtIIl11 diflp]lws ill ((JlllPllttUliollS of 1l-in lil lolutioll alollJ with till 1lIltbpl TIU data ill wbh +ho on tIl( hn~is of (olorilllPill ladillU thaI tll( IIUOIl1t of lnbbll Plllipirntld 110111 Ilwthyl olnlld kptOlll olntioll IJ 1li-jHlllnt 1l)04 in 1-llltlIllt ethallol)- not amlll hy thl llllNlI(l of llvin aU1ouut of llins inolution bull
-----
26 rECHNICAL BULLEfiN 920 U S DEPl OF AGRICULlUHE
100
90
80(I) C)
z Ci 70 UI a 0 60 a ~ UI ~ 500 ~ 0 I Il 40
30
A 20
0
100
90
(I) 80 C)
z Ci 70 UI a 0
60a ~ UI E 0 50 ~ 0 I Il
4-0
30
B 20
0
--
--shy ---shy---
2 4 6 6 10 12 14 16
---shy= ~ ~ shy
-
2
025 05
10
15
20
25 -30
35 40
SO
-60
=70 80
16 20 2224 26 26 30
OS
- 10
IS
20
2S
30
35 40
-50
-60 -70 -80
bull MGPE 25-ML
VOLUME
bull
MGPER 25-ML VOLUME
Florm 12-EtTld (If till1l or Slllldill~ 011 light transmittallce (01 (A) gUllyulc lnUIl(I plccipitllitd frOIll llltt h~l isobutyl Ielollt solution Ily neidilic(l ethanul bull null (B) gUllyule ll~illii pre(ipitated flom aeltoll~lllcetOlll-Cl])osolY( 3-7 solushy11011 by H(illilip(i l1U (HPlldillg~ nt -lIlillult Ifllpluls 011 Evelyn photoelectric colorimellr with jU-lllp tlllll alit U-1I11 npN(lle spp also table 2)
bull
bull
RAPID PI-IOlOMEllUC DElEnMINAlION OF RUBBER AND RESINS 27
TADIbullbull ] 4-ReZation of amiddotmount of middottbber pleeipitate(Z Oln metltlIL isobutyl ketone 80lutions by OS-pereent H 2SO in 95-pere(lIIt ethanol to umollnt of resin8 udde(l U8 indivute(Z by colorimetrio readinU8
(Rubber ami resins cnlculntcd on bnsis of amounts in 5middotml ullquuts of extract from 02 gm of tissue in a 2fllll olumo( bull
Hubucl r~cocrell whcll rcsins nddcd as IndIcated Htbbor al1dcd (pllcollt) ---shy
__________bull_________ ~_12rpcrc~15011crccllt 7511crccnt IOOpcrcent
PerCtllt ercellt Percellt Percellt Percent o o o o o) 50 250 263 252 25000 500 500 500 500 700 750 750 751 749
1200 1250 1250 1250 1250
EXTRACTION TEMPEHATURE AND TIME
Typical experiments to detllmine the time required to secure maxishymum extmction of rubber und ltsills at 115deg U Ilre sUlIlmarized in figule 13 the solvents used-methyl isobutyl ketone for rubber anrl Ilcetonylacetone-cellosolve 3-7 for resins extraction-are very eflicicnt since under the conditions indicttted maximum values were secured after 30 minutes of ext1llction The most eflicient liquid for the bath (lig 1) used in extrtlcting rubber or resins is ~ high-grade cylinder oil (S A E ~O) The sand bath and such liquids as glycerol have proved unsatisfactory
RUBBER AND RESINS STANDARDS
According to the National BULeau of Standards 1-_ lhclc Is no gellcrnlly recoglllz(d standard lIIutcrlul [ior II rubber standard] The rubber hydroCllrbon ill llifferent samples of conmlcrciul smoked sheet or pale crepe from heclI pluntlltions nries from l~ 10 04 llercent of the totul nutletmiddot the most 11Ioruble conditions Of preparation
McPherson () has described a procedure for the pLeparation of pure heve~ (Hevea brasiliensis (H B K) MueH Arg) rubber from crude rubber or latex In the absence howevcr of ~ generally recogshyn12ed stalldard for rubber hydlQcllrbon [caoutchouc (CnHUs) xJ the standard adopted was that of the relnthely pure product secured from gunyule tissue txtractiotl nccording to the Spence-CaldweU method (5) or the motlified PIOCCdUlU of Hohnes lind Haasis (p 2) The details for constructing the calibration CULes are given on page 10 Standard rubber samples apparenl-]y can be stored for a long timc under the conditions des(libed on page 10 The duplicate colorimetric lendings for glULyule rubber newly extracted by the modified SpenceshyCaldwell method were ()J2 ench as compared with US) each for the sample extracted by the same method but stored 1 years In each case colorimeter rcadinllS were made on mixtures containing 2 mg of rubber in It 25-1111 Yolume
The selection of tt suitable standurd for guayule resins presents some dilliculties Tll(~ acetone extract of gUllyult estimated on (l gravishymetric busis~ for instance proved to be variable depending on the type of tissue sampled or season of sumpling because such fractions as
COllllllunlcntion dul(lt1 Octohtr 22 11H3
28 QECHNICAL BULLEQIN 920 U S DEPT OF AGRICTTIIlURE
16~==========================115 shy
14 bulli= 13 z ~ 12
ffi II Q
10 c w 9a w
8gto () 7w a
6a w
5en III ) 4 a
3
2
A 00 5 10 20 30 60 90
14~------------------------------------------- bull13
i= 12 z w II ()
a 10 w Q
9 c w 8 a w 7gt o () 6 w a 5 If)
z 4 If)
w 3 a
2
o+B~~__~__~____________~__________~ 5 10 20 30 60 90
HEATING TIME (111 NUTES)
lllGUltE 13-lDffect of time o( lICntillg O2-gm samples of gunynle tissue with solYlIt nt llfio C on lo(OVl)ry of lllhlJer alld 1Isim Lt HlIhblL extracted with methyl isohntyllwtone B resins Cxtll1cted with aCftonyla(etonc-cellosolve 3-7 bull
chlorophyll are weighed along with the resins in the acetone extruct but are not estimated by the present photometric method (fig 0) 1he use of a diffeJent stanclttrd waS therefore indicated
bull
bull
bull
RAPID PHOTOMETRIC DETERMINATION OF HUBBIm AND HESINS 29
The resins standard selected is based on n relatively pure source of resins the rcsinous exudnte 011 the stems of guuyule plants IJldimishynary expeliments with the resi nouS cxuclate from diffcrellt gllayu Ie strains of various ages indicatc nHlt there is little YaLiation in this subshystance on the basis of Colorimct(r readings 011 2-mg aliqllots of 01shypercent solution in It 2i-ml volume (tabl( li) Expelilll(lnts have shown that the air-dried (xuclate contains 3RtOH p(Ic(nt of -volatile matter This material is l(latiyt~ly stablp ill (OlllpoBition and is npshypurpntly on ly slight ly hygroBcopic as shoWIl ill Ia bl(1 1 Tlrp Ipsinolls exudate may be jJleplpd in two wayi-i fl liSP as a stallClHld-(l) the clpan exudate is clripd iol Ghouls at ()1deg C at W indlPs of a(lIum Hnd aftclbCinOglOund ill a molfalis 1)I(spI((I intn airtight COllilinel OL
(2) tllP Cx7lclate is clissolllt1 ill a(lhllll and filtplpd PlactieaJlyall of the acetm1l is thpn lYapolntwl olt OPI a stlam or atCt hath and Ow residue is dripd ground an(( PI(sPIld as ill tllp fin lllethocl Tlwse two prepalHtlolls a1( (ompalpd in ta hlp ) 111( (((tails fOl ~t()lil1g the resins standald and (onstlllcting the calibration CUITPS alc given Oil page ]2
lAIIIg fi-CUIIIllrsoi (lJ lIr-dr(1I IIIIi 1((11 II II-()I-tr((l l(sil~ 11111111(8 of I II 1111Ie
[Colorimetric rrndill~s 011 1~I11 phulll(Iclrie eolorillJct[lr with i~()middotmll (100- to iiOIIIIl) fillcr [lnd 5-1111 lIperture preeipitantl part ofO5middotPIrctllt 10 to 5 paris of IIOj
nupliclllc(oloritwt([
nIl(lin~s (hIlSlcAg~ ofSlmillXo JrNliltlCllt of fPsiJI$ L1Xtlrlntp on 2 IIIg ofplanls fllsins (XIHIIlt~Jwr 25-1111 vol
tII1(1) 1
leflTs Various _ bull ____ bullbullbullbull 3-9 Colll)Josiltrlairmiddotltlricfl bullbullbull nf)2 002
])0____ bullbullbull _bull __ _ bullbull ~-l Composilld (ri d at n5 C in aUmiddotimh lWUUllJ for l (jOuj(ja hours])0______ bullbullbull __ bull ___ bull 3-0 COJIlpositld disso]NI in neptolll f1l1erNl fl(lf()ll( GGO i(jO (Ivaporntld olT OV(1r Stpl1l11 halh TesidlH drl(ld I1t fi5deg ( ill anmiddotinch VIl(Unlll for 0 houlS bull
middot106 __ bullbull _ Jir~c1rild_~_~_ _~_ ~_~ _ ~ ____ _ __ _ OUu GOifina_~ ~ _ ~~_~ ___ _ _fln~ ~~ ~ ___ ~ __ 6(imiddotI tiliA H)[_ ltlu bullbull i18 tisSflOabullbullbullbull__ bullbullbullbullbullbullbullbull lt10bullbullbull _ tillO llitO406__ bullbull __ bullbull __ bull __ __ lt10_ Utl2 fon591_ fo__ bull liGa oOa 406bullbull _ __ lt10bullbullbull_ li5S OM
j Ph( vnluls in Uw Inst COIUIIlIl indieatp thnt gunyulp fesinous (IIHlnt( wlwtlwr dfircl hi Yn(tlLJ1l1 wilh L~ perc(nt loss of volntllt wutl pr or tWl c1rild giVPd npproxil1lnh1ly t Iw snllw colorinwtCr rNHiing- 011 till busis of aliquot~ cOlllniuiug 2 IJI~ of flsillS lXIHlntp l)tIf 25-mI volultl( Ihil- illdicate~ thl11 Uw UITW IJ1flS~ of olnshytile mntl(f prt~(iJlitnt(d gins npproxilllntlly Uw $1II1l (oiOfirnl1tlf ftudiTlJs ns tho ftsidtw A pnlill1jllaf~middot (XIlltrinllnt indicutls thlli th VUllltill muller l(lIlSists of thl Ilrplne oil fmcl ion I5-(1Il gtnplls or rlsitlOtlS (lxudntll gnvll by stPll1U distillation nn Uefllgl of 011111 of jl(lfPlIW oil with npproximHte tilllsity (If OHIi lind lhus rrprlsll1ll( IlPIJroximllt(I~ 01 Jerccllt Of t he original weight 1hls lllrClnlage complrcs wllh 38 llltrC(ntlost by drvinI( in IICllnllJ
aSplusmnUH perceilt or orlginlll weightlosl
The wailnble illfolJllntioll on tlH (ow-JitlPllts of the gunYllle r(~shyillOllS exudate alld tl1( HeetOlIP ext act of gaylp ti~slw is sllIllmarized in this paragraph lYalttI (u) alld also Hangcn-Slllit lind his coworkshyers 16 reported that 20 percent of the resinolls exudate from gUltyulc stems is parthenyl cinnamaie (CHuOH=CHC020 11JI2r) Steam disshy
15 (OIlIJIIIIUicatioll flom A T Haai(II~l11it llId (0011(11 Calif0111 ill Tnfiitnte of Tccllllology Past(IlIJI Jhps( wOlken al Htud~ing the COTlHlitlllllts of the acetone extract and other conlltituellis of guuyule
30 TECHNICAL BULLETIN 920 U S DEPT OF AGRICULTURE
tillation of similar resinous exudate in the writers laborntory has yielded approximately 4 percent of the whole as the telmiddotpene oir fracshytion Haagen-Smit and his eoorktrs nportec1 thttt about 25 percent of the acetone extract from guayule branches is parthenyl cinnamate and 6 percent of the bark (ltortpamp-phlotm) extraet is parthenyl cinshynamate These workers fm-thcI reported that 25 lwletnt of the nc(shytone extract frolll bLllllches is a compound with the tlI1pilicaL formula CBoH400a 1 percent is a compound llwltillg at 2P to 2T5deg C and 1 percent of the extract from the ]eav(s is tl (olllpoulld nwlting at 100
to 1710 1Valtei (6) reported that 3 to -l perc(nt of the tI(eton( txtract
of leaves and flowering StPIllS of guayulc eonsists of waxlike substances soluble in olgallic soln~nts but insoluble in at(l and (on(ent1llted H 2S04 The flactions mentioned on the basis of (onHLTutle esti shymates of amoullts actually isolated tlecoullted for about H ptIcent of the totalncetollt~ so]ubles extracttd from tll( guuYllle 11 rub The other constituents ltlilaill to be i(](ntifi(d
RUBBER AND RESINS CALIBHATION CVHES
Typical culibndioll Clllves iol Iuhbpl and I(sins bas(d 011 (ldtLminttshytions made nccoLdillg to the plocCdmC outlin(d 011 pages middotb to 1G arc shown in figulPS 5 and 1+ The spCdlopliotoll1lttL en (OIOIjlllctCI readings are plottCd on s(lIlilogalitllllliC pappi ag-ail1st (Il 11IbblI (011shy
100 ~ 90
80 ~ 70 ~
z 1amp1 0 II 1amp1 IL
1amp1 0 Z
60
50
40 ~ltI 30 ~ en z ~ ltI II ~ 20 C) ~ oJ
10 o 2 3 4 5 6 7 8 9 10
RU8BER IN 25-ML VOLUME (MG)
bull
bull
bull FI(lURE 14--Ctlihration curve fotmiddot gllftYlIlc lubb01 (Hct(lings Oil COIPIIHlII tlOl1hl(
monochromator SlCClrophotolllet(r with 7fiO-11IL Illtel alld Hllp Wll ( IHlll()
bull
bull
bull
RAPID PHOTOMETRIC DETE~MINATION OF RUBBER AND RESINS 3]
centrations From a casual inspection of these CUlTes it would appeltr that Beers law does not hold Actual tests indicitted that Beers law was applicable only within a narrow range in the upper portion of the curves The analyticlil results on the basis of photornetric readings nre therefore calculated by direct reference to calibration curves or from reference tables of equivalent values bllscd on the cnlibllltion curves
Calibration curves for kok-saghyz alld heyea lI11tulltl rubbers and Buna S (GR-S Chem Gum IV Goodyear) and butyl (GR-I Standshyard Oil Co Protoc) sYJlthetic rubbers are hOWllil1 figure 15 The samples of kok-saghyz rubber were furnished by the Diyision of Rubshy
100
90 ~I) ()
z 0
1amp1 a
~ a
80
70
60
s 1amp1 ~ ~ 0 ~ KOj-SAGHYZ 0 l Il
50
HEVEA~ ~
40
100
90
~ 0 80z Q 70a Co)
a 60 ~ 0 0 x 50Il
40 ~----~~----~------~------~------~--~ o 2 3 4 5
RUBBER IN 25-ML VOLUME(MG)
FmUIlE 15-CaJiblation curves fOl kok-snghyz h(YCII Bunn S lind butyl rubb~ls (Readings on gy((yn photoelectric colorimeter with i20-lIIp filtpl and 6-ml aperture)
32 TECHNICAl BUIJLETIN [)20) 1 S DEP1 OF AGrnCUIlfURE
Iwt Plant JIl(I~t ignlioll of thi BlII(un and (1( l))(parcd according to 11( SPltI1((-Culd (]] (6) PIO(((lllll Hlpt pal( CLPPe was (xtmch(L with acetone blI()Ieit W 1I(gt(11l a ttnlldal(l
SEXSlllVllY Ol~ llETJIonS
By lip pIO((l(II11P olltlillP(l 011 ]Hlg( +n Iowa (lOOl IIIg (11 1111i(l0shygmm (gHlllllla) of 1hblI ill a 2)1111 yoltll1ll (all )(gt dltpltld Oil tltl Col(man (lohlP mOIlWhlOl1lHlOl l-I)((t 101 l1lOt 0111 ci( I ill1ilnlly 001 mg of Iublwr ill a 2J-1ll1 n]ulllP Illay bl Ilad Oil till EnI)1I photoshyllectlie (O]oLillllt(I Thll ya lllll- 011 tilt IHl-i- (J I (xl ad iOI1 fmlll 02 gill of til-lI tH(JI(lillg to tllP -lllndal(l jll()(pdull 1(PIPStlIt IlO()2J tlnd 002) P(IT(lIt of llIbl1ll IPI)(((inly bull1t1lollgh -lI1t low allils can be d((d(middot(1 il lIoullt1 Ill IPtllizpd thnt till PIIOl ill PlI(Plltng( or tll( al110unt dltlIllIilll(J i ltlatlpl high ill tili PIY lo Itlllgl 111 aetllllllladie(middot Ill( lopl lillliL 111)(1(1 lIw (ollllil ions of tlil ]lI()(lltlIIIl u ol1tlinpd ipt at l11 11I1 or 1111gt11(1 illt i-1ll1 Ollllll IlPIPltPlltillg 01 p(gtl(pnt of JllUiJtL un tlll 1Hli or (xlla ion rlOI11 II rlll of tisSIll
EIlIlOH COSIIlIHIIO
In Oldpl to H(IIp ill )1lHtPltt pl((iioll illlpIi1I- it i lH((SSHI to slnlldHIdiz(i rigidly 111( Pl()((dlll( 0 illdi(ntpd Oil pnglt- - to J( If lids i dOlH tlip lXIHlinwnlal PIIll is t(middotdllld 10 n ndninlllill
Illlt pl(iioll of (hI ]lIPPllt 1IHllwd Oil til basi of ]llllP llIllJt1 alld Ipsinssollltions call hI jlldgl(J 110111 figllll Hi lileh lio- til HPIlIgl d(intioll oft -illgIP lI1lnSIlIlIIIlnt in lHi((lltagl of Ill( alllOllllt 01 Illhshy1)() 01 lpsins d((PI1I1 iJlld TIl( (1101 PlI(Plltaglt H1( gi (1 101 OJ) to
RUBBER IN 25-ML VOLUMEMG) 004 01 02 03 04
i= I I IZCtOW
fbA ICtU CtCt WW a
01 02 03 04 05 06 07 08 09 100 = RUBBER (PERCENT)
RUBBER IN 25-ML VOLUME (MG) 10 20 30
~ I CtZ
bBOw Ctu CtCt Ww o I~
010 50 100 150 200 250 RUBBER (PERCENT)
RESINS IN 25-ML VOLUME(MG) 10__ __3-0_ 40 50 60 70 60 90 100--_-- 2_-0
Ct~ -r- 1 I OZ
WCt UCt b C wCtW
a o I I 150 250
RESINS (PERCENT) o 10 50 100 200
bllI 1tI W-Yllnl dtd1 ioll I I 11l1 11IlI11 1(111(11 1 III Plll- IlIIIlol1 01 IIim~
bull
bull
bull solution Il basis J o golH of tiSSII (JlILCl-nt (11(11) for (~I) (l)1 til O 1I1
of luhllpl lin 1 III I (I Ill of lUhlJPl nllll laquo I J to 111 nlg of IlSlllgt (Itllillgs on ]iYllyu pllolwh-llrk CO[IJlilll(-(PI with nOHIP Iiltlr lIntl U-lIll allcrture)
RAPID PHOTOlJElRIC DELEHlllNAllON Cn HUBBER AND H1~SINS 33
10 mg of rubber anel1 to 10 mg of resins in a gJ-m1 yolumC For
bull
bull
bull
comparative ptuposes the leslllts arc also calculated on the basis oJvershycentage rubber OL tltsills in 02 gllI of tissul As WOlllL be expcet(d the error increases sOIlHgthlf for 1(lali nmiddotly low COlHell t1llf iOlls oj rllbbeL or resins The curves in figure 1(j s1l0 that ill til(gt Illlge Ol to 10 pCrshyeent of lubber the elTOI rangts Jroll1 abollt Ll to II) ]IlC(lIt abo(~ this mlllc tIlt (ITOl d(((ts(s to (ollsidlItbly ltmiddotss (han 1 1lICPllt of tlH mllollnt ltl((Lmill(d Hil1lilally in tlH (lISl of l(sins analysis (fig 10) the ltLTor is (onsit1eIubly INS than 1 PlLllnt ill (he lallgp of 11 t~) ~() penPII t
In nil ([lSl of lllhblI alld (sins lx(Inltpd tIOIl1 (issups Ol addcltl to tisslle lxtlads (s(( tabhmiddots (i H) illyolillg ll01P o(lllntiolls the eLI01
is hig]wl thun that indilHtld in figllll ((j Im pUIl Ill )])p I tllllllsins solutlOII
COlllUCIIOXFOH IXSOLl-IlLl~ Ilgsqgt(Jg
111 th( Jllo(pdulP ollllillPd 011 paw I till illsolllhll isSII Ipidll( tflpl (xttlw(ioll is (Ptill tlw lIask l(lll till xtlct i l1wdp up to yoltlllH It is not rOllPllipnt (0 IPt()PI qWlIltitati(Ir III(lw[olH a 11(1 pllooll extlnlfs of guuyull I is-lll alll thl1l main t11l111 up (0 YOIUllllmiddot bpCaUHI sllch all additiollal stltp wottld]) tillll-C(JllS11ll1illg Th( Iogiea nll(gtIshynntin is to mnkp tltl lXtlUCt Llld Ipsidup lip to OllillH in till original flask andi llPSStllY 10 llwlno tl OIIpdioll wlHIl (allIlnting [hc llshy
Hults f(JI [hl oll111lC displupd hy till ins()lllbh llsidll( III it l)picat (IXpednHllt (ollsisting of Jhp lppJiea(iolls if was Iollnd llftt at ~iiO ( 02 gill 01 Iuhhll pillS IPill-fl(( lisslI(gt (lollpdll fot llwistUlC ou basis of dlyillp ut lOW 101 ) llOlll-j (lbp(ld only t~ llllUll voiul11P of OOk7D~- OO(lOO(i Ill of lllthyl bolnl(yl 1lIOll( (lplhlli(al-t(Tnltle sp gl () Ii I ll(Hli (j at ~)) -gtitllP tl1(gt 1It101111( () r t is-lIl xt Iadld j sl1lall til( PlIOI dul to Ill(gt insoll1blp Ip~idll is slllall III [0111 ill( wOtk it (all lJp diIpgal(ll(l
]hcon~lIY OF HllIllgl AiO HESIS AIH)gl) TO EXTlIACI OP
GlYlLE TISSlg
Tnl)ll G L(IHpslntillp (ypi(nl llld(~ SllOS (hat all a plngl of HIOK PlI((nt ot lltl pltl( Ilhl)(l acldpd to tllP Itll h iolJut1 InmiddottcJllP xhnet
of guayulp tiSI1( WllS 1l((PllIl Tlli nllintioll flOlll (olllplpU I((OYshy
PIY i within flll pxp(IiIlHuttllIIOI ~illli]llly fnbll Ii llows thn 1111 llYlIUgl of 1O(1~ ])(I(Pllt of gllllYllII 1(-i1l- add(d to II( (pllosol( (xshytrae of IUllY]l t i~HI Is 1l(oPIPI
THl~ (~ Hf (Off Ill of 1111)( J OJ I~il~ lItfI(( In ~(JI1IJk~ Ilf (111 [lI1Il fI2 lIII
0 tlUfllllit i~~I1
Instrument
---- ----~---- bull shy 1(1
Colemun ruono~ltrOUlllt()r 2t) II sJl~ctroJlhOL()lIIeter with 2tJ I iflllllI wnclength Fetting 21 II nntl 0-1111 WU HI hUJl(L _ L U
Ill 7Evolyn photo~lcclrie (olor JU [ imctcr with iO-llIl filler IV (I
H1 0 t I I
llImiddot lUn WII 1011 HIO Wn mil lUulon
10 JIg1111 IUI ml lUl anh Io aLn 111)_I ) III li lU It 2) deg wn2SU DD
Irl JIll II IIr II US II
1110(1 lULa lUI IlK) IJ WU
I( llI Htl tNI 1(111 2tlNI HI 0 221) lllil t2S 0 1~ 10 1~13
In (I 2117 I
10U 1l(J ~ 4 _H_j ___
9middotJIlJ5 10115 10 00 lUU5 flUU 4li (tl03 9(11)
leIlKl 1l~)5 lOOU l1KIr JOIS un 003 OIl Ii
34 lECHNlCAL BULLErIN 920 U S DEPT OF AGRICULlURE
COMPARISON OF PHOTOMETRIC A1D MODJIoIED SPENCE-CALDWfLL METHODS OF RUBBER ANALYSIS
Guayule samples were analyzed by the photQ111etIic method and by bull the modified Spenc(gt-Cnldwell mcthod The values in table 7 represhyselltativ(I of typical results indieate It -atisfactory dcglpe of conformshyjty between the two methods in thl range of tiSSlHH with llHHC than OJ) percent of rubbtImiddot On the bnsis of the amounts determimd the results in this runge for the plmiddotts(nt lIlcthod ayernge apploxinHltely j percent highcr
~LAIII~ 7-(oIllJl(i~on of lltlllrIic (IIri mOtllinl SJl(II(r-(ulri-wall IIIrtlwrl~ of rlrrlIIillillfl 11)1)(1 COIIrll of UI(III
1 Flowers frllm amiddotmonth-oltl nursery plants
YAIIIATJO- OF SIli(LE DETEnt1NATIONS Fnoll TnEIIllIEAN
Rllbbel (Uall8i8-Thc plcCision of thc pLcsent method when gunyule tissues Hr( nnnlyz((1 for rubber may be j udg(d flom I Ill datil presentcd in table H TIl(se dahl -how that thl pplCPlltag( uriation of single determinatiom from nwan yullles with low standllrd enolS ranges from less than 1 to 4 p(gtrlent
R(8in~ wWlsi-r-s lndi(a((1 011 page ~j he INntlts s((uled hy the present phoolllttric nsins llHt hod are not tliltly (olllpalable with those of the grtLVimetri( ncetol1l-cxtlt1(tioll II1etho(l Thjs made it necesSllry to selc(t another lalibllltion staudud-tlll Ipsinous exullate from gullyule shrub-thut gies relatively COllstlllt photometric readshyings (table 5) The resin (olltents of guayule roots branchcs or leavcs usually ran(~e from about) to 1-1middot pelcellt The ple(ision of the present methotf WhCll gUHyule thslllS lIe analyzed for reins may be judged from the datalHmiddotpscllted ill table 9 1h(se data show that the p(lcelltage variatiun of sillgle lhmiddott(Lminntions iLO11 meun ynlnes with low standard NTOrs rangcs from about 05 to 4 percent
bull
bull
bull
bull
bull
RAPID PHOTOMETHIC DElEruIINAlION OJ RUBBEH AND HESINS 35
IAIILE 8-luriation inclieute rubller (mallSM of [1wIIle tissue bll thc 1111O0Illclc metwII
Vnrlntlon~Ilbher I (rom mean
ierCtnl Percelll ~OU -22 ~ 25 +27 ~ 20 +18 ~UO -22---------1_______ 51110 0G6 bullbullbullbullbullbull _bullbull
10 ro ----=ii41075 -01 1000 +11 1010 +13
rlln HI itil 1l9~ 1_ ___ =-~~~
115511 ~ US -111 III II 1575 -13 115 b tiS -I a 111 h WlU +22IIM-(middot bull 11K -1Ja Illi c 1000 +03 1J5H1 W +l)7 ll1imiddot tl 1575 -13
Mcnn 15951 131
1102-11 21fJ() +21l102-h _ ~~)SO -17 1102-c bullbull 21CO +21n02middotd ~OIiO -26
2 r~plusmn Il~ 21151 261 I -~-------bull---__ _~~_~______l-___--_
1 lhe$ 1111($ I1n (or SlIlIIllltS Stpnnltplr PHrilClld IIrtlrdlng 10 1hr prollIlIlr( OIiIIiIl(o(I on Imgt$ 4 to IC ~tcond nUlI1 hlr r(J)[ltnts stl1ndnnl llrrot of tilt 1I1(1111
1_1l1~ n-J(lri(iot in relli(Upound rpoundsins (lllalIsfs of VIOJII( lixsue b1 the lhomillric lII(lloli
-- ---~--- - __-------- shybull I I I I Varlgttton
_________~___ ~~lu_n_Jl_Q_~~~_____ ______I__~_o~S_J frOID lDean
Percent Percentgt458-1 ~65 +41IWtl-li 130 -a2Hli8c aliO +26S41i8-d bull 130 -32
1(-011 34I10Olifgt __ bullbull __ ~--====
li-9~2n 881) -06 li-9~2-b Si5 o ~HH2middot(middot S i5 -6$-H2middotd 000 +1
8851 054
O i5 +6 9 i5 +6 950 -20 U75 +6
H-liG3o-n bull -1 n-li6~b bull __ _ -IH-IWH +4H-l61511 bull -1
1tmiddottlU
62~-lI __ 62~-b ij24-( bull OH-Ji
(-Ull
I rll(St oluls nre tor separately ~xlrflCled SllllllllCS IlctOrdlug lO procedure outllned ou pages 4 to 10 i Secoud number r~prtgeulS stulldMd error of lIe menn
36 TECHNICAL BULLETIN 920 t ~ DEPT OF A(]RICCLTCRE
ReUUER A~ALYSrS I~ CRCOE-RcuUER PROOCCTS
Sew rapid photometric m(lthod~fol the ddellllinttion of rubber and reii Hi ill uaYllp ti--ut htp lllell pIPHnl pd oil pag( ~l to In A brief H1111111tlY of It similar rnpid llHthod fm 1I1hb~rllnltlysis of u1lulcanizNl tlIldp lubbll pl(Hlmtlt whielt i~ bn-(tldo on the prill o
ciples dehtilcd tlllLe follows Duplltate nt-gm sllmph of the finely cliyiliNl IlInttlitiup wlirllll out [~ei-()l (all hl lIf((tinmiddotjv INd to lt1iyidl till alllpl) TIll kltolll-olubll portion of till )111(11( tlrc di-olved a- indh-Htpd fot thmiddot lllnkill~ of -tlllHlunlluhhll olutiou Oil Pt 1II hut tIl IUlIp Hn lIn l-fplImiddotd 10 lHI-ml rolllllltti( fln-k antil1ltld(lup to Olllll1l The bnlulUp or till JllO(ldllll i- thatutlilllll on paWs -1- 1 IHI Ii 111( 1(111 1- nIP IXPIP--pd nil til IHi or Iw oligiJla w(lullt of I Ill (I11l1p-I1l11Ilt1 1)(0(11(1
Hupitl PlllimiPJojgtiWllllllllh llIltllOd~ fOJ Ihl llPtlmiddotminntion of ImiddotUlJbll tlnd 1(-illo- ill -111111 Illllph of gutlYllll tiUl IIll dl-eli)ed 111() IlltlY d~o Ill nltlI1lld fOl III Iwl Illhlwl- and l~iJlmiddotb(lLiJlg plant TIllt l[Olllhup hns nlo b(l1l ntuptpl fot IIH lltlIll1illtltioll of lllhbpl ill 11lHhrublwl Pl(Jdlld~ HIIl 1111 hI ndaptld JoJ IIll ann lysis of ynt1J(gt( ic lllbbl[- The llllthmb HIP 1gtn(11 fill tIll fol1owill plimiph- III Grinding
tIll PIOPlly driPl t i~lIl 01 Ul tillg tIll pnHhHt to tll l((lllilllllh~lel of filWlH-- til plllllit qIHlIllilnth( lXIIHtioll 01 IIlbhlI 01 1(--IJl- () llsing oXWllutld olnuh (kttoJls IIt(talp and() fllltil for LIbbel and IH(ltIlIlyptIJllIllIoolYlnJld-o flJllh 101 niJlsl with t(lathelr high IlPililig points 111 to n C) l]olle or in mixt tIll thllt Pll mit tlll rnphllxututioll of luhll(l OJ [middot(ill ill ~() to (l mi1lutp It r(latiwly high 1lllIllllltlltP Ill to 1~11 ) l) lllllipitntillu till luhblI OL Imiddot(ill frolll aliquot () f till oltn ion I IlIlllI-i () f Hlltabhmiddot pl(~(i]litallt (willifhmiddotd lthmwl fOl IIlhlHI Hild llitlifild lllr fOJ JP-illl t~) IIlHkillphotollllliilPIIIIiIlof PlllPlltal of liht tLaIlS mittUl(P lIftlI IlIlbll (II Il in PIlipitalioll 11 II WI( Iplllh thnt (limiJlall till PIIOl dill 10 xtralllOlh (0101 (till dptl1minntinll Iph jill 011 tIll dtwlopllIlJIl of H HIli rOI1ll tlllbidity 111 hpl than I (olot rI
jJlIlpOP-ofallnlyi-I ( p(lllil1thb IIllijOI1ll turbidity or 1llt[lIinmiddotd d(ltl of jgtIp(ii(JlI l)~ lIltlkillU tIl plllltollllmiddottri( ntdillU al tandinu tiJlH~ (dlllilll wlli(h IhlllH(lill-- IP 1llutinmiddotly tnhll) t1ll1t an hlsl~1 oil the (oJlItlIlllItion of IIlhlHI Ill I(ill (lIPIipitat((L
TIll -I(p ill till jll()(Plhul HIP 1-- follOylt (1) 1l~UIIL uJ1lplls of thwl UJfJlllHl (II tliddl(l HUt dlipd 11Illtplial an lXIllltel with11 Ill of till nlnll ill t (oU tlllltIPlll[gtPImiddotatlup oil Iath at 11 Cbull fol 11 minutl I) iIP1lIin(middot(lohd til( (XUtllhllll Jltldl lip to It middotml ynlmlll til( (nlifild by (Illlifllgiuu HlId thlPl IlI nliql1ot of tIl (IalioPlllxUlltl nll Uillltlmiddotll(t to l-llll OIlIIlIllril fiuk- (1) For a trial Ilnditlg 0111 III tlll j liJmiddot~t IllHII IIjI to Ohlllll with lilt Pll shy(ilitnnl a 1(11 it 111 (Dod fill llli lIut ( ptotoJIIltlil IPtlllillg-- of pllllntnl or liuht tlUtllIlillal(I oil n (lpel OphotnJlllllI at rase hng-tlt (If 11 llJ Ill Ol It lollllil1lPtImiddott lloyidld with tIll P10]11 I 1110110shy
Ihlolllltt hmiddot Ii1llI Olllhi lIatioll for -1IpItillg UJlproXilll1l tply Wtl P ]Plwth )0 mp are HHlltk TIll Illldillg lliJtaillld fol tIlt 4-milutl tliall(~ll-
bull
bull
bull
RAPID PHOTO~IETRIC DETERIINATIOX OF R(BBER AXD RESINS 37
ing are referred to a table of equhmiddottllut~ previously p1(pa1elt1 on the
bull basis of 4-minute reac1inJ~ for tilE nmge of lot1telltlatiol1- of rubber or resins to bE elHOlll1t(led tmd gidn thtmiddot -tnnlillfr tillIP fill rUbbEt or resins aiter prE(ipitlltiol1 lwfolE photoIllNliI j(tltlill1 un IUade The r(middotnmining dllplllatt aliquot lll then HHllil up te ol1l1Jle and lpoundadillg ale marle ut the -tandillfr tiUlE iudklltll ill rhl tall1lmiddot for the final r(adillg~ -1) 111( milli1lnm or p(tCPlltllt- of lllhbpL (II 1(-in pr(s(nt are rpadholU a prlpan(l table of lquiltlput for tlll photoshymetric readings h1~l(l ill pnell e1-E on pxpPlilmlItal lhln 1111(1 u-ing as stimtlltlds pure luhbll in 1l1bbtl milllYb aIHI guaYllh ll-ill- lxIHlatt~ in resins detNIl1111lttion I
LlTERATlRE CLTED
(1) lUnSbull 1fl36 THE mURMIXTIOS IIF IOTA RE I III OOl THER llT~II
F1 bullrol IlY U(T1l0fll UfSlfi ~rrnrl r flm lt1 KEYS TI Bill Chern 114 44J-l59 illns
t1 ~ICPHHlObullbull T 1J3bull~ lUTHOO roa THE PtRInCAnu Or a(lIUl IRrIlHU It of TIn
PLRIHEU Htllllflt [ i Bill lallllall 111 Rmiddot 711middotj iIlus
I ) RHBERG P B Ul5 A METHIlO Or ~u(ronrll-nl Hi tIII rUIl[1 f71 ii illlI
bull 14 Hoss W flbull and HARDESTY J O
llH IR1ltDII Of HfITilIZfmiddotR DllIJS ltt 1 Yl fll Off gI bern JIIIlI i ~middotmiddotlf IIl
101 SPEltCE D nnd CuoWELr ~I L 1933 DETER~n-ATIOo OF RtBBER Ii nrllllpoundRBfR Iusr 1uI II1 amI
Em~ifl cttIliIa~~ r Ell i 71middot7i l11 (HI WALTER E D
1U44 ISO~nlS OF PRTlltSrr 1trHpoundV bull l UI n W lHHt (Tnmiddot 1ETS FROM GiYI l~iIl lItr Clttrn SII J UI titJ middotn9--C1 ilIu
17 J YOEbullbullr H lO~( roLORIlETRT 771 IPmiddot nl -W Yurk f H Plrwptric hmica
naly-II rimttry lUll XphHHlnmiddot~ y 1 1
11
HI) ~ fPHELolzTRf 57 111bull Lin xw Yk t H lt PhmeHt CblUlmiddot ila AnaiY~l~-(H lithrry and XIhmiddotILpfIY Y wirh enomiddot rrJlllrjr hy H KtlJnJU11 I
t~1I --- and ~ARVER L 1f41 nlua-w ~in L liLhr IS IP ll~ XIW Yrk
bull For-sale by th~ ~a~fr1nt~nf1ent Dt~c~~ogtnts-~ s t1i rArnn~ut Pn~~~ tJffieshy
Washington 5 D C bull Pl lU ~nts
bull
bull
bull
RAPID PHOTOMETRIC DETERMI~ATIO~ OF IfCBBER A~D HESI~S 17
Dry ucilht lust ill lariOilillf
Plaut (pcrcrllO 1 1 -I2 ___________________ _
213 _____bull _____ bull __ _______ ___ ____________ 12 2(
pound(111_ ______________ 1 R
4_______________ _______________ __ _____
A __ bull __ -_
The efred of parboiling on till final lllalp i SUllllllatmiddoti7(middotd ill figmc G Rubb(1 lecoYelY w(t about 1 percent higher for parigtoillltl plants and lEsills re(ovelY somewhat o-er 1 i)(lr(lllt 10Wlr The (Ii tference in lublH-l r((o-elY cannot be ae(01111tltlt1 fot by loss in dry weight _ due is to be found in a study of thE grinding lwhadol of a parboiled and an unpnrboilEcl shrub The grinding of the patboiled shlub in the hnml111 mill is much fadlitated and ns a rule for tissue with a rubber contCnt below 10 peteent llO aggregates of rubber deelop in the 1Il11ehinr during the (Jpelatioll Yitll the unpnrboilNl shrub some dillictdty may 1)( (lxppliellrl(l Sill(( sOllle of till sti(ky ltxlldutl Oil the plant may scI( u nlldei for the fmllHltioll of lublH1 ngglPgates Til is apparently explnins the npparlllt los in ruhbpl frol1l the llnpariJoiled hrllb as eompnlelt1 with thl palboilld (fig (i) TI1(loss in r(sins
II
RUBBER
10 f-
Ishyz LIJ 0 0 LIJ 0
9 --RUBBER -shy-------shy
-- RES INS -shy---shy-----_
IJ) 8 I--Z IJ)
LIJ 0
0 7 f- RES I NS -0 -shy0 LIJ III III J 6 f shy0
LEAVES REMOVED BY PAFltBOILING
5 f shy -shy - BY HAND PICKING
4 I I I 35 30 25 20
SCREENS (SIZE OF OPENINGS IN MM)
FIGlRE Ii EtIe(t IIf pnlticlp sizE Oil lEcorPQ- of rubber lind (iiil1s when lEgttiye wEre remond hr Pl1liloiling lind h~ hand pi(king ((Dlltrol) plllllt1lt groUlld in t hammer mill
6114038-46-3
18 TECHNICAL BULLETIN 920 U S DEPT OF AGRICULTURE
recowry from pUboil(d shrub may be due to the loss of the resinous exnc1ate during parboiling This exudate forms ns It SClim on top of tlw )iquol in the tank
On the basis of t1wse results the recommendation is made not to yaly the nwthoC of leaf lemoYal in any 011( lNi(lu(h project Then fltirly compalabh IcmLts should he obUiined
70 ~------------------------------------------~ LEAVES REMOVED
BY PAR80lLING ____ BY HAND PICKING
60
-I-Z 1amp1 0 50 a 1amp1 a
en 1amp1 gt1amp1
40en gt-CD Q 1amp1 Z
I shy 1amp1 30 a l shyx C)
1amp1 ~ J 20 I shy 0 I shy
10
O+--L__L-~__L-~~--~~~~~ o 10 20 40 60 80 100
NATIONAL BUREAU OF STANDARDS SIEVES (MESH)
FlGntE T-lJiMlil)utiun of l1Ultkh si~(s of gnll~II( tiSSU( JrIOllll(l in a Ball amp 1ew(1 mill to pass six dllIerNlt S(I(euroII 1(IlYes Iemoved from plants by palmiddot boiling 11(1 hand picking ((olltloll dpfo1iatld plants dried to 1I lUoistufl l0I1t~nt (If 01 to o) 1)(ICl1It ground tiSSlli IbalH1 1() minutes ill II ~i$hel
bull
bull
bull Kahn shuk(f
RAPID PROTOMETRIC DETER~UXATIOX OF RrBBER AXD RESIX-i 19
GHl~DIgtiG
bull Th~ entire pant 01 plant l)iHt a~(gt fl r(ll it pllllIIirU1ry lSillg fur J hours ntGi~ C prIOr tD t 1( plChmll1atmiddot rLlmhll III a II lItmiddot or n Ball amp Jewell mill ~n llltllysis of paldch lzP- nftl~l (oar-( IIindill shows that tlwy ar( about tIlt llllH fOl parbojlP(t awl IJllllluhoileu hrubs I fir 7)
The coalilly gloUllll ample i-- thPll Ildlll forI toUtmiddot at ni C afnr which it ha lllilobtllL(gt output of ~ llllut lII hmiddot- dptPlIIlilwltl by drying submlllpil- at 1110 fot hOtll- TIll 1 IIIIll i lltllt lmiddot0l111d hi a IluninHl mill TIll mo(lel uP(t in thi IIIk i 1I Hu IIIOilll mill as IllUllifill bv Hoss nnt Hartlet ( 1 -[1lt111- with n1ll1l1 pldushyrations ittI lilnbhell b rill HanlIolll V0ll11nHiol1 ElIillllmiddotrill (0 The size lutllihl11 iUlJnole So I ( 111m t ~ II t HUIII Xl) ~ I L~ 111m nnd So 4 lillllU1 11 ttllilhmiddotj 0 r tllP Imiddotlult~ p(lln-It willI t11(e Sll((IIiZtS with )arl)Oiltll awl uil)Jtllboiltd hrlll b lOwl1 in fif1l1fmiddot-- This hows t tnt 1middottttIl ~(I 1 llllll (Up jlllilnl IHlt that
r------~-------r--- ~ --r IHAMMER-MILL SCREEN
O~ NO1
NO2 ---shy U NO 3 ---II
I
bull lL
z
r ------ l 30 ~ gt III
i I Imiddot
i ~ I
I 1 I I
~ 20 I - 1 iii 1[ r 10 ~ ~ ~ I _ ~ I r A bullbull
o bull L-~__~__~~__- ~~ 20 40 60 80 100 40 60 80 100 200
NATIONAL BUREAU OF STANDARDS SIEVES (MESH 1
Yutln I i-tlillltiuli Hf pur id lZt f ~naY1l1 t middotnt r1 lI1 i ~ a hatlltlllI 1IIi11 to 1111 Lx IHtllllH middotIn Lt-anmiddot tIlllunl loy la1 litkh~ omrl t 1) tHul parbuih~ -t B ~ thmiddotfuliufptl ]~lahr thpt tu tt fit t 1 It+gtr-tt1 Jnui~tHn eunttlIt _~rnlitl tl~UP ltakmiddot~~ 10 UddU it~ 1 rtmiddot4~pt~middotK1~r ttakt-middot
bull So 1 gingt- 11 tt-liuin-Iy ltr~pl [lPlItl1tat of iilll 11animiddotImiddot- Eqltrimiddot tIlllll hnnmiddot llOWIl dutr fll llltldllllUU xtlutioH 11pound lnhbll lIl lP-ill frolll IolUlIl ~tlaYlllt tl-IlP by dlt IJwtmiddotlUlmiddot lItlilwd oil Ill 14 - 01
i-mllt 11111- -lwltld hi INd I li~ Ii I TIll lllhtIlttj of Itiu~ So 1 (lltll j thnt 11middotmiddot01middot lttwmiddot to amplil tltt Iollllli tilt art lpdnn ib
IntIIll ll~ i po--ihJI with tI lLllit Ilfltl[lll1t It honld l Plllplw izmiddotl rImt ilt tht h of -allllhmiddot with l lllblPl
~ontlnt of ill PPltllt til lIilll it i tlllt pll--ihl 10 11-middot t(1i Xli L
20 TECHNICAL BULLETIN 920 U S DEPT OF AGRICULlURE
Even with screcn No 2 difficult due to rnbbel tlcrltreCtlltiollS may be ob tl
encountered In thes~ caHeH it iH lWit to parboil the shlub fOL leaf lemonll and finally to dry to about 1 to ~ P(l((llt of tnoiibl1(l pound01 b(~t results jn ~rindillp in tlH hanmHl mill
It iH aclvlsable to provic1l thc hammer mill with a ground wire Hillel the presence of static electric (harges 011 tll(middot partkhH will ealls( Home of these to atlhelc to the inside of tllP (olltailWr OJ lila eallsc OI1l( of till pULticl( to form ngg1(llatls EIIolin lalllpling fl01l1 fhis SOI1I(I mlly be (onsi(h1llbl(middot
A1I10l1g the Holnllts with high boiling point that lIlay Ill IlHld in rubber anal)Hs I1IP Illllhyl n-alllyl ketolle methyl ioblltvl kptOIH diisobutyl (tOIH blltyl tHptate llethyl amyl 1Ittail (middotthyl(middotlllmiddot gly(ol diethvl (middotther and n-bntyl (middotthel (labl( 1) TIHse al( also I(sin 01shy
middotent but th( 1(~illS n1( held ill olution by the rll1)bpl pl(l(ipitant tthanol wll(1 lllbb(r is 1)J(lipitatNI (S(ll tabl(s alldmiddotl) On tIle basishyof the lxpHilllPlltH tll( btsf nil-round lolPlli -rol lS in 111( PIlHPllt method is lt1iisobutyl kPtonc wld(h was not IIltlllllfaltllllmiddotd ltIlling Vodd Yflr n A suitable Sl1lgtstit ute iH llHthyl jolllltyL htolt whi(h is l(porhd as llolltoxit UJ)
Clllos()IY(~ (ethykn( glYlol monopthyl (tIH1) blltyl earlgtitol (di(thyl(ll( gly(ol llIollobutyl (ti1(r)~ and acttonylacetOll( may be used as resins sohrCllts (table ] )
In the earlipr work with (sills analysis cpllosoly( alolle was selcmiddotet(d as a suitable solycnt Aitholllh (ell()~oh( alone is pxc(lllnt its rplllshytiwly gwatlL iscosity 1(I(b to bubbl( formation nft(I (SillS pr((ipi tatioll Thi- increased thp (xperimentnl (LTOI OIl of tltp othll I(sins solpnts tI((tollyla((tolH has the proppry of glpatly lNlulingshydH(OSity 11(11 altld(( 10 othr liquids This sohpnt tlHIeforl wa addp( to ((Uosoh( in slIflici(lJlt tlllIonnl to OPI(0111e the dinieulty On the basis (li~ex)le1inwllts ~ purts oi~ a(donyla((tOlll to I puts of (elloshysoh-f (bolll by olume) as Splldcmiddot(l Thp 01 hel Hoh(nl listed hutyl clLlbitol at l(llst the t((hnieal-g1lld( ploduct uSNl is appal(ntly not as good as eithe of t1w ot1(r two () a (ombinatioll of tlWSt
The SOlVllIts JOI liSt in tumlyzing artifkial lubbel$ hy tlw pr(senf method appllLently (lcllIHl on th(middot kind of llI))(I lIp-ityl (Jxidt is suitable Ol BUlla fi and hutyllthlI for butyllllbbl Tlwse reagents IlLe technical g1lld( Calboll amp CtllUil1t Ch(lllilai (OIP This Hllbjp(( hilS not bepn (XtpllHl(ly illwtigated by till WIit(I
PIIECIIIIJ-
All tlst fOl Ih( adlqlJalY or till IHllipitullb ll(Ollllllentillllll11Sl bl baset] on the plctisioll of tllP final I(snlts oiJtairwd with the methods The )redpittlllts s(1e((( n HpJ (xtcllsi( (xp(IimPlltatioll all HatiH~ factor (Hee fig Hi 111lt1 tabItmiddot (jH) Ext(IIin tllts llllTild Ollt hanmiddot shown that H Hatil-gtflltlOIy [gtIpeipitallt 101 1lIbblI is (li-p(IT(middotnt HzHO (c p reagent nil POll sp gl U-lmiddotJ) ill li-P(l(Put (tinmol by vohmlP liol (tllayul( Ipl-gtinl 1l)-P~ITImiddotllt H)~o ill Hl) by ollln( ii lL satishyfaeto7-y l)lp(ipitunt A solution of 1 palt of H~~o to 1 part of H~() (1-1) iI2So1 nnd abo yarious int(lIlIPdiat( proportions of tlllse suhshystanCPs giyp fait 1(511It8 but with till inlIptl(l ill [h(gt ratio of H~S01
~
bull
bull
bull
bull
bull
RAPID PHOTQlIEfRIC DETEMIlXATIOX OF HtBJER AXD RESIXS 21
to H 20 the )olutioll becollles somewhat vbcou5 and precautioll Il1Ult be taken to ttvoid bubble formation When it i5 poured into tilt Cllvettes
It should be lloted that both of these precipitants have an ftellleshymmiddottion It was found that when XHjOH was used in the rubber preshycipitant in pInt of H~~O~ the readings were -table l)Ut were not reshyproJutihk The lIl of XuOH in pInel of H 2SO j ran nHittble result as a llth H(HY(Pl WIWll til( li-P(l put lthatgtl in lublltl llnalysis or H~O illlP-ius anal)j wn-i uddint(1 thl eharalteliti(s of till liquid with pleeipitated ruhber or resiu in HI~P(ll-ioll n ren1 on the lpNmiddottroshyphotometel m tololinlPtprfollop(1 it lPgnlal lIlll II~ lxplaiHd on pHgP-I (Sl( figs 11 aIlIIl) Tid made it lloible to outain lEPJOshydlHibll tpnlt nntI (onplt1J1(Jttly till JpqnitPIl tlPgJPP of PJPcljoll
IIWIE(TI 1lt COl~101J)
Jtl thp ItJiPl middotxlwlillltnb hefoJ thtmiddot -1l]YIlIt allll pnmiddotdpitallb had lIptll ptoppJly adjutp(l it l fOllll tIuH till llP or a Ploltiw colloid -wll ltIi1)cJ [ttlJmiddotntl- imlIopl tll lmiddotpro]lIibility of the lPlllt JmUkllly ()Ilt 111 U lput lUlU illlihumiddot tOJllPOlUtl tpHd liglyeol teltlut( - llpanlItly IllmiddotlfP(] to lit til I1m t IHflll lImnnmiddott nftlr tlH filial prOIptlllll WtlP dlvPllill1 tlll 11lIlpfit (If thtmiddot [llltlltin lollohl wa Hot 0 natlv I1l(lhmiddotd III rlumiddot Ia- of tmiddot ill tllmiddottJmillaritlu it b [1 hmiddotjlmiddot til IIpoundgt Ir llH1 It liltr ill-llImiddottiT Ina lll ptlPII by it U( in ruhhfl mmly j 11If dtmiddottail fOJ tltt lllllmtlllll If thl plot pet in nlloid ~llntill tltlmiddotlImiddotmiddotlttlatiflll lIOlllllllhtiPI1 are iPllllll page
liTFHFEHliG COIOf
(hi II tht lllail 11111111111 that had til ill -111111 II urklll) om tlH method fot lublJtt tlIlO1 rpir- nlalv~i in plaut llllpll- wa ttl (lilll~ inare tIte (gt1[01 till to tIll ptP-PlHt f xi [aIWIIII- 111 TIlt amount of (olor varip from lUllIt tn -amp ]pplwHlI nlt rhmiddot lt IIf thE Hl(ltllial tllP part of till plllIt -lI11lhmiddot(l tilt hi-tlllY f tlll plaut mtteshyrial ~ub-lltInent to Itlllmiddotnmiddot-rill lliI 1011middotly OrllPI Inlw
In ruhlwr lrtl-i I Iii 1101 au Itmiddot 1Iplll11l by 111[ I--r ratmiddottilt thE -lllll]t with uptoIw or 1middotmiddotlIll-ol - wIdell [llllol- rlll loillriu nutttel autI thtmiddot lpill- Thi- howmiddotvt n(tnll- til lXtla -11gt1 ilt prlJ~edun) In lP-ill ltluay-i nllHufldy tlW[t j 11 1 1IO(PIlln fill the 11shylImya of hlulophyll Hwl rIlI-r middotIOII IHlttlmiddotJ dlH lUtl~ In plltIH withoUt alo aiftIriL till nmiddot ulttrll
111 pllIbIll1l Wi tilmiddotr hId h It-ImiddottHI tht Pltlpll 1 hlitlt lilt tlw tulllWlli tollImiddot uIwltllIIntut -lltUIhorlllllltll 1111 tIll tlettlllliIttwr IIf t 111 lWlrl-Uamiddot of bdt tl11blLlittUhmiddot r [1 tItmiddot preshyj
lipitatifll 1lJ llllllWI atbull 1iI- in III -1nrmiddottIi fHlttalldh nlrillU~ amount rf middotlorilig lIUlttll Iii lhll of ih lltmiddottllllhottohttt~l l~ol()r infrtl Hm II upd 1 rwmiddot tld~middottilmiddottll PlllItlhi~ f it j proYitiltl with tIll lilP--UlY tU(jlIdlllIlml tIltmiddotmiddot lllklllUIlI
EIECTIol OF 1 [EGTH~
-Ptfmiddott ral tracilull ru~lI gtIll fr 1 nllb t ~xtltd 1 lIlt-th vI iobmy1 ketommiddot lWtl rill [ Ixt lttltt ll UttollylaIiIitt1l11I1t~ ~-I itoiu YtHil)u~ typp of ~IHaylllt f i lItmiddot art hraquoil ill fio1ll1 ~l Th~ lp-nlt fill I11oohl uio[1t ttl willlr til tltN- fur rht IUiXtIUt iwliutll
100
22 TECHNICAL BULLErIN 920 U S DEP1
90 bull eo
I shyz 70LLI 0 a LLI a 60
LLI 0 50 z
a ENTIRE 2-MONTH-OLD PLANTS~ 40 b ROOTS AND BRANCHES OF ~ 3-TO 4-YEAR-OLD PLANTSen z WITH LEAVES REMOVED ex 30 a C CURRENT-SEASON GROWTH OF l- )-TO 4-YEAR-OLD PLANTS
20 WITH LEAVES REMOVED
d LEAVES FROM 3-TO 4-VEAR-OLD PLANTS
10 A
0
a Cd 100
b bull
10
80
I-Z 70LLI 0 a LLI 60a
LLI 0 50 z ex I shy 40 ~ en z ltI 30 a I shy
20
10 B
o~__~__~__~~--~--~--~--~----~--~--~ bull350 400 450 500 550 600 650 700 750 BOO 850
WAVE LENGTH lM~)
FJGcm O-Sll((middotlllll tramaniW1IHl (mrpS f(JI (xlmll 11011 n J1ll of jlta)nle tissur ill n 2--m1 Y011111P of (A) Illrthyl ji1I1J1ltsl krtonp 1111(1 (ll) nt(middottQnyla(umiddot tClIc-C(l1osuln a-i
bull
bull
bull
RAPID PHOTOlIElRIC DETEH-UXATroX OF ntBHEIl AXD HEstxs 23
ThE dula Pl(S(l1t(lltl indi(ntp Ihut 101 Illp ulimls llHthyl liohutyl htOlIl (lxtrHts (lI(I r(dolls of Il1Hxi11111III nigtol]gttioll wiH1I all (is-lIb 11 cOllsic1(]((l n1( blhn(11 wn ( ItIl( Its lIO to () I1It~ nlid Ii to Iii mJL
WhllNIS tlw I(gions of 1middottnL(s( light 1lnlllittamp al(l lgtPlW(PIl wan Ipllgtltsnr) to Ii nllt jW) 1I1JL nlld alio Silllill1l 111l1b (n SI(lIlId 101 nc(ton ]altmiddot(fmiddotollp-(llloolp ~ pxt Ill of 11a 1111 t illl TIl( (1101 du( to lolo ill tlw litlltitl a 1Il1 lullll(I tH lPill- hanmiddot bpllI PI(_ ipitated ma he 1((I1((d to fltI ynbhing poillt II ph( illg OJ illshylmiddotJall(( WIWp balld nhm ()) IIIJ1bullbull[1I111 lxjlPIitllll1b Illln -h()1 that Ih( lIIot uilahl( WHYI lHlIJ fOI 1-1 ill 1l11J1l(I HIH11Pill- illllllrsi i-in till IlPighl)()lllll()(l of ~llIl1lt bull
bull UIlIilHlIy of n typhn] lXPllillllllt to )10 l1iP(tiP ((JIlllo( of (ItOIS dul to lOIOl in 1llblnI Hnd Iill xtnumiddott 11(11 IIIIolp t jUl i p1llelll((l ill tub]lL Till llhlllt- 1tpIO]II Hnd ((llll~()h whit-h UI(I ](]Hllilltl n 1I01lllIhb1 01(111 lxt 11111 IIll 1llll)1 nmtp[in I and )(middotills Tid IIlnkl it poiblp nftlI tlIp uplll1tillll or tlll o1PIl( (0 [niH lip 1Iidl1p~ of lI111 11111(( ill lit ll11l1)[1 (llnlIb nlld Ihll
Sl(ll n ol1lliOI with tllP olnl IJllt illiollt HIl Iltlllll llllI (Ill ltllthpl prpipitnnt j Ihll1 nddld OUI ha a lIilPt lP( of till lIiciPlw of WH( lllIgth 7) lUI- ill llilllillatiu (nnl till tll Ixtll1I101l ()lll~
Tuu tmiddot-Elilll IJl flrldillY 11-1111 lrlllI IjfJI til islII 1 1(1 ([rllt IIIIIJIlIr JiIlIt~ if 1Il( Ihll 111111 k til I III Ilrln I 1Intd tf 11111 JiSf fill I I II I tIII Ilf Iilltl 1f1JlIIillII1f I Till 1[ 1 IId 1 (I (middotIt 11111 (I1I1iI1 1lf1IWtlfJlIIllfflr p middottrllhIJ11 II J III 7IImiddotIa 111 111 lilt jJIp 111 wilTII
t~t tnVIli~ ~nn r kn t~ i tmiddot ~~l Jr 1middotmt ltlTt
HmiddotOtt ~I~ lin t I ~ 1 t~~l ~qrmiddotthtmiddotrtwb
Hult-middottltlru t T Hw ullut rHtt~ r II I ~ PH~lllt
A~tmiddottHHjmiddott~rjd rl ~gtllh 1 tn~th~ ~ ~ middotI lt~ b w bull hmiddotth~ 1i~lIhun 1 Ii tnl Illd1 -11lt1(11i lullI lUI tJl ll~ t1~11n( I Ihan1li flfttIJir Ult I Uuhtltt ahuul l(hmiddottHmiddot~t trv r fti HIt lftbyl tlonhUt)1 k_hIl( 2 m~ fmiddotf tuhlHmiddotr In mlth~ llmiddotlf- 1 t r
t r_~ t j
Arhlitlltd ~llIIDHl NcWitn1 ( Ar-(lt()nc~middotttrrtrt ritJJI~ -Iu nllJtl4-middotr
ACtmiddottflnp fmiddotxtrn( ~ T-P511ftf tn mtmiddotth~ 1 ~difmiddotut~ kdn 2 nltt ulruhhtr in Un-tIl lltbu )J~IYt
rUth(Hl~hltlft HhubU
Illlh(I(t tttUtUt hUbtl til J ~jlitl(J Hilllll trtIIImiddotjtl1ll
(UShl I ~tlO wHllolH rulh r (middot1111$0]( J~rru t t )lthyl 15bullbull1middot1101 klll1l
Ili( UHUicbcul ~((i1rUtl ~ulu1iin 1middot lIUIll Ilti lrllltlllt I Ruhhr llt1thuI r1 -1 Irld
ltlt1111Sh 2 nuz f)rruhl~rm nlith~l tu- h f nt nil~middothgt(H] tlrlftmiddot 9lUtirtl middot1 1
rlcltfl( H(l dnllltml it
(IISllhH~rI( Iultruhtr CII05 1v ltTlft I 2 UI~r ublwr In llldh I hlt~1 11) lgtjdvr(llsl~9rlltmiddot middotlmin ~ I~ gt AIHItilltl no IrttipHallr iI
~ Bbnk 10ol m(thyl i~tmiddotut~i kdHn H 1 m1 j~~ l1rH-t lt~tlfltmiddotn sf n it ll HltlMjftr~nol O2~mlJ ~U~1o-ulp ti~tW -xtra~middotl(lt1 ltt 411 ml bull ie f Ct- kft rt t~ tirattJ middott ill r u l1kn ttJt
in metltl isobutyl kNqnf nn~i mljp ur tmiddotmiddot ~oml ~urr tttl i t w ltJj1JH kt 4t 3 nlank 1 mL((l1t~rthmiddot(middot mI mttr~ ~but a kmiddot tmiddotc d 11 ~ gtli~b~ hifIAft- fl~ lL lnti 149
ml8(dlfilll BO bull 02 gm guayule U$Stl(middot xUlClt-l tf(h tft wI n nmiddotmiddotmiddotlgt 1 lznt on tmiddot ~Jt r~1 ~~u~~ H~ iI~ thT
24 l$CHNlQAL BULLETlN l20l S DJltJPT OF AGHl(CLlOHJltJ
In table a is pl(sentc(l such c1il((t edlt1tIHC showing that thc (0101 Ixtrnetccl from guaYIIle tisslIe wit h II(P(OIl( n nd (pl1oso[yc is cll(div(ly sCIe(nec1 out by the s(lp(tion or wnw length )0 miL Oil t1w SI)((IOshyphotonwtpl This tnb]p all-HI ihos thai thl Juhlwl altl(l((1 (nn IJl quall shytitntivcly 1(I(()(Ipltl in tIlt PI(ilIH( or Ih (o]OIplnwPIials and Illsins and tlmt Iuhb(l WtlS nppnlllltly 1I0t (xtltI(((1 110111 11l glll1I1l lisslIt b~ tlHSP SOhlllts Thls( ((suIts ginmiddot (OliIHillg (idJt(( that t Iw IISI of waYl llngth i)ll 1Il) OIl till SppdTophot OIllltPI ii t hl 1101(1 p(oshy(ellule in photolllliTie IlIlalysis of luhhlI OJ l(sin-
SELEGTIO- OF )IOiOCUHO)IAIIC ItIIm ((1111110
On th( basis of th( IPHIlb shoWIl in tabl(l 1 al hlllpls (1( IIln(lp to SPCtl lC the PIO]Wl 11101lO(lIOl1ln til Ii ltlJ ((lIllIJi nIl ions 10 llIiOlS (oIOlimet(Is 111(gt 7W-Ill~ filtpl flllnhwd 101 til( I1~lI1l photoshyplpct1i( (o]oriJl1ltll fol which Ill( (hlll(IlIiitit~ oj t hl Ilda he light ilUIlBlIIhiSioll (t) elll nn -hO11 ill fig1lle 10 iws satlsfa(lolY IPshysultl 111( iiO-mL HitlI olllhintioll 101 whkh ttp (middotIatinmiddot light tlnnsmission (ullmiddotis a 1-0 showlI ill figllll (I is -nthdnlto1 hut this is not stnlHlnld NtllipmPlli
Up to fhl PlPHllt lIS(middotflll pound11((1 (ulllbinntions jn lltl iOO-I11L Iunge hayc nol bllll SlClIlld 101 lhp Klpt 1-1I1l1I11PISOIl (olOlinwtll bu fnltlwl nttCl1lpti 1( )(illg IlIHd
TJIpound OF ST~lmW AFTEH HIIJ1EII Oil HHSIS rlll~CIIITTI(J
~ considl1ltiol1 of ttp lillll of Inlllling af((1 plpeipital ion of 111gt)(1
01 l(sinSTlOIll ollltionis impoltant J(jl~ thC1HI(Plltngp of light IInIlSshy
11 rshy10 f shy
09 f shy ~750 Mil- DOMINANTI
~ 08 cshy I WAVE LENGTH z
I III III i O7 - I III
~06 - 05 shyw
a
Igti= 04 - 720 Mp DOMINANT ct WAVE LENGTH- ~ 03shy
02 f shy
01 t shy 1)O~~~gt~- J 600 700 800 900
WAVE LENGTH (Mp
bull
bull
bullFIGlRt IO- COJllPIUlItiw ~IW(middottltll tlnIlRlllii-lion (II (IllP( 101 1i11(1 olllhinulloll
with dominllnl Il(lllllgths at 720 and 7iO lUi
bull
bull
bull
HAPlD PHQTQlfE1IUC JjETER~lINATION OF Rnmrm AND HEtiINi 25
mitted (spertrophotoll1eleL lCuding-) Ol light (1 (tClcrl (phOlOshyJluol01l1et(L lcndillg~) i~ StlhjNl to (hangl
]fjt~l1le 11 and l~ show that ill til( (asc ot tJaugtIllitteltllight llJHC th~ (x[llliHlllIlnl (oIHlitiOllS tllpl j lilst n dtlln-e ill Pll~(lltngl or UllllslllittnlH( follrnY(l by It ptJiml of lClntin stability with only sliuht (1111 tHn- a f(Pl a lIt1ll1btJ of minutes The light t UIllllitblllll t l(1 ill(Iln~(s This lIIay IJP llllllJltlli7P(ll1 ffl II ow 1Ilt )( f(( darI oliIII tIIlIlNlIlitt(IIIlfJIIlh (iditilIiid Ilil1 pllIipintnl )uoshyIn Of ( 8inx in (~f1( I~iUII i~ Ild stahl I 11 itlll If 1inl nh prlshyilli(ioll of 11l1d(1 II IJIX f) jllIli II (fJJltfiIIlilty slllMI IIriot 1) IIIPldUnl1i tll(I1I rllltltilJl oj tJi~ Jlt jiot IUN ilUf Jxl1 will tIt( tOWI IItlllilil I 1llIlllblJIol I ill I~11l11111 d ill till ifjuids JjOI scnttplltl light 011 till phololltHJIOIl1lttl till dilPCt ion 01 elangl b tlw IPrfIi (If that illrli(atPll rOl tlulll1Jittp(lliuht It Itlll b( llluliJr I-(Pll that if l(middotndlnJ- IIIP mad n itl I t lIP ~()ll1d()lb lpalll this pllioJ of nmiddotlatirp tuigtility tllP llLot tIOllt thi Olll(P (nil bl IPdUCld to tIl lltini III 11 Ill TIll l~adiltg (illH~ bbll Oil tlHl datn rUl lublwls and llsinlt Illl ginll ill tnhh
50 r----------------------------------------------- f shyZ
~ 40 ~----~W~A~V~E~LE~N~G~T~H~7~5~0~M~P~~~~ ~ --------------------=-=-= ~ 30 f- WAVE LENGTH 540 M~ _z _____ ___ -=- __ _ ~ ------shyt ~_=---=-=--I GUAYULEIII 20 -Z HEVEA ltt II KOK-SAGHYZ f shy
4 6 8 10 12 14 (6 18 20 22 24 26 28 30 STANDING TIME (MINUTES)
FIlirtn 11 Emmiddot of wav hll~rh Il li~ltr tlall~lIIit1alHl aftI IUIlItHt -Imlli lug 111m for guaynh llmiddotn 011111 middotiolIlJh~z 1111111 llijlitul1 flolll 1lHlh~ll1Jllryl k11II11l ~(lilltlll h~ lwitlitll 111Inu1 111l~1It1 2)1111 o1U11111 (Helillins on (illllun tlunhll IlIIJlllw]ntllW111 lutl(I[lholtllllltlt with ijUjt Wlnl IHI Ilf1 I
11 EFFEGT OF Hbli 1 -()JXT10~
Tilt lnblwl ~()h(llh pxtnl( till IPillgt ubo It 1m nllu1- bellt -~atea thut ~lll 11-111- tUP olnbhmiddot ill middottIIlIlOl ~1It tlWIIJI( my U)t PIl (tlIHatcl WIth tl1l lullh(t I tahle lJ 1hln 1- -1111 tIll (llllstlOll of nny p()~iblt tITptt of XtIIl11 diflp]lws ill ((JlllPllttUliollS of 1l-in lil lolutioll alollJ with till 1lIltbpl TIU data ill wbh +ho on tIl( hn~is of (olorilllPill ladillU thaI tll( IIUOIl1t of lnbbll Plllipirntld 110111 Ilwthyl olnlld kptOlll olntioll IJ 1li-jHlllnt 1l)04 in 1-llltlIllt ethallol)- not amlll hy thl llllNlI(l of llvin aU1ouut of llins inolution bull
-----
26 rECHNICAL BULLEfiN 920 U S DEPl OF AGRICULlUHE
100
90
80(I) C)
z Ci 70 UI a 0 60 a ~ UI ~ 500 ~ 0 I Il 40
30
A 20
0
100
90
(I) 80 C)
z Ci 70 UI a 0
60a ~ UI E 0 50 ~ 0 I Il
4-0
30
B 20
0
--
--shy ---shy---
2 4 6 6 10 12 14 16
---shy= ~ ~ shy
-
2
025 05
10
15
20
25 -30
35 40
SO
-60
=70 80
16 20 2224 26 26 30
OS
- 10
IS
20
2S
30
35 40
-50
-60 -70 -80
bull MGPE 25-ML
VOLUME
bull
MGPER 25-ML VOLUME
Florm 12-EtTld (If till1l or Slllldill~ 011 light transmittallce (01 (A) gUllyulc lnUIl(I plccipitllitd frOIll llltt h~l isobutyl Ielollt solution Ily neidilic(l ethanul bull null (B) gUllyule ll~illii pre(ipitated flom aeltoll~lllcetOlll-Cl])osolY( 3-7 solushy11011 by H(illilip(i l1U (HPlldillg~ nt -lIlillult Ifllpluls 011 Evelyn photoelectric colorimellr with jU-lllp tlllll alit U-1I11 npN(lle spp also table 2)
bull
bull
RAPID PI-IOlOMEllUC DElEnMINAlION OF RUBBER AND RESINS 27
TADIbullbull ] 4-ReZation of amiddotmount of middottbber pleeipitate(Z Oln metltlIL isobutyl ketone 80lutions by OS-pereent H 2SO in 95-pere(lIIt ethanol to umollnt of resin8 udde(l U8 indivute(Z by colorimetrio readinU8
(Rubber ami resins cnlculntcd on bnsis of amounts in 5middotml ullquuts of extract from 02 gm of tissue in a 2fllll olumo( bull
Hubucl r~cocrell whcll rcsins nddcd as IndIcated Htbbor al1dcd (pllcollt) ---shy
__________bull_________ ~_12rpcrc~15011crccllt 7511crccnt IOOpcrcent
PerCtllt ercellt Percellt Percellt Percent o o o o o) 50 250 263 252 25000 500 500 500 500 700 750 750 751 749
1200 1250 1250 1250 1250
EXTRACTION TEMPEHATURE AND TIME
Typical experiments to detllmine the time required to secure maxishymum extmction of rubber und ltsills at 115deg U Ilre sUlIlmarized in figule 13 the solvents used-methyl isobutyl ketone for rubber anrl Ilcetonylacetone-cellosolve 3-7 for resins extraction-are very eflicicnt since under the conditions indicttted maximum values were secured after 30 minutes of ext1llction The most eflicient liquid for the bath (lig 1) used in extrtlcting rubber or resins is ~ high-grade cylinder oil (S A E ~O) The sand bath and such liquids as glycerol have proved unsatisfactory
RUBBER AND RESINS STANDARDS
According to the National BULeau of Standards 1-_ lhclc Is no gellcrnlly recoglllz(d standard lIIutcrlul [ior II rubber standard] The rubber hydroCllrbon ill llifferent samples of conmlcrciul smoked sheet or pale crepe from heclI pluntlltions nries from l~ 10 04 llercent of the totul nutletmiddot the most 11Ioruble conditions Of preparation
McPherson () has described a procedure for the pLeparation of pure heve~ (Hevea brasiliensis (H B K) MueH Arg) rubber from crude rubber or latex In the absence howevcr of ~ generally recogshyn12ed stalldard for rubber hydlQcllrbon [caoutchouc (CnHUs) xJ the standard adopted was that of the relnthely pure product secured from gunyule tissue txtractiotl nccording to the Spence-CaldweU method (5) or the motlified PIOCCdUlU of Hohnes lind Haasis (p 2) The details for constructing the calibration CULes are given on page 10 Standard rubber samples apparenl-]y can be stored for a long timc under the conditions des(libed on page 10 The duplicate colorimetric lendings for glULyule rubber newly extracted by the modified SpenceshyCaldwell method were ()J2 ench as compared with US) each for the sample extracted by the same method but stored 1 years In each case colorimeter rcadinllS were made on mixtures containing 2 mg of rubber in It 25-1111 Yolume
The selection of tt suitable standurd for guayule resins presents some dilliculties Tll(~ acetone extract of gUllyult estimated on (l gravishymetric busis~ for instance proved to be variable depending on the type of tissue sampled or season of sumpling because such fractions as
COllllllunlcntion dul(lt1 Octohtr 22 11H3
28 QECHNICAL BULLEQIN 920 U S DEPT OF AGRICTTIIlURE
16~==========================115 shy
14 bulli= 13 z ~ 12
ffi II Q
10 c w 9a w
8gto () 7w a
6a w
5en III ) 4 a
3
2
A 00 5 10 20 30 60 90
14~------------------------------------------- bull13
i= 12 z w II ()
a 10 w Q
9 c w 8 a w 7gt o () 6 w a 5 If)
z 4 If)
w 3 a
2
o+B~~__~__~____________~__________~ 5 10 20 30 60 90
HEATING TIME (111 NUTES)
lllGUltE 13-lDffect of time o( lICntillg O2-gm samples of gunynle tissue with solYlIt nt llfio C on lo(OVl)ry of lllhlJer alld 1Isim Lt HlIhblL extracted with methyl isohntyllwtone B resins Cxtll1cted with aCftonyla(etonc-cellosolve 3-7 bull
chlorophyll are weighed along with the resins in the acetone extruct but are not estimated by the present photometric method (fig 0) 1he use of a diffeJent stanclttrd waS therefore indicated
bull
bull
bull
RAPID PHOTOMETRIC DETERMINATION OF HUBBIm AND HESINS 29
The resins standard selected is based on n relatively pure source of resins the rcsinous exudnte 011 the stems of guuyule plants IJldimishynary expeliments with the resi nouS cxuclate from diffcrellt gllayu Ie strains of various ages indicatc nHlt there is little YaLiation in this subshystance on the basis of Colorimct(r readings 011 2-mg aliqllots of 01shypercent solution in It 2i-ml volume (tabl( li) Expelilll(lnts have shown that the air-dried (xuclate contains 3RtOH p(Ic(nt of -volatile matter This material is l(latiyt~ly stablp ill (OlllpoBition and is npshypurpntly on ly slight ly hygroBcopic as shoWIl ill Ia bl(1 1 Tlrp Ipsinolls exudate may be jJleplpd in two wayi-i fl liSP as a stallClHld-(l) the clpan exudate is clripd iol Ghouls at ()1deg C at W indlPs of a(lIum Hnd aftclbCinOglOund ill a molfalis 1)I(spI((I intn airtight COllilinel OL
(2) tllP Cx7lclate is clissolllt1 ill a(lhllll and filtplpd PlactieaJlyall of the acetm1l is thpn lYapolntwl olt OPI a stlam or atCt hath and Ow residue is dripd ground an(( PI(sPIld as ill tllp fin lllethocl Tlwse two prepalHtlolls a1( (ompalpd in ta hlp ) 111( (((tails fOl ~t()lil1g the resins standald and (onstlllcting the calibration CUITPS alc given Oil page ]2
lAIIIg fi-CUIIIllrsoi (lJ lIr-dr(1I IIIIi 1((11 II II-()I-tr((l l(sil~ 11111111(8 of I II 1111Ie
[Colorimetric rrndill~s 011 1~I11 phulll(Iclrie eolorillJct[lr with i~()middotmll (100- to iiOIIIIl) fillcr [lnd 5-1111 lIperture preeipitantl part ofO5middotPIrctllt 10 to 5 paris of IIOj
nupliclllc(oloritwt([
nIl(lin~s (hIlSlcAg~ ofSlmillXo JrNliltlCllt of fPsiJI$ L1Xtlrlntp on 2 IIIg ofplanls fllsins (XIHIIlt~Jwr 25-1111 vol
tII1(1) 1
leflTs Various _ bull ____ bullbullbullbull 3-9 Colll)Josiltrlairmiddotltlricfl bullbullbull nf)2 002
])0____ bullbullbull _bull __ _ bullbull ~-l Composilld (ri d at n5 C in aUmiddotimh lWUUllJ for l (jOuj(ja hours])0______ bullbullbull __ bull ___ bull 3-0 COJIlpositld disso]NI in neptolll f1l1erNl fl(lf()ll( GGO i(jO (Ivaporntld olT OV(1r Stpl1l11 halh TesidlH drl(ld I1t fi5deg ( ill anmiddotinch VIl(Unlll for 0 houlS bull
middot106 __ bullbull _ Jir~c1rild_~_~_ _~_ ~_~ _ ~ ____ _ __ _ OUu GOifina_~ ~ _ ~~_~ ___ _ _fln~ ~~ ~ ___ ~ __ 6(imiddotI tiliA H)[_ ltlu bullbull i18 tisSflOabullbullbullbull__ bullbullbullbullbullbullbullbull lt10bullbullbull _ tillO llitO406__ bullbull __ bullbull __ bull __ __ lt10_ Utl2 fon591_ fo__ bull liGa oOa 406bullbull _ __ lt10bullbullbull_ li5S OM
j Ph( vnluls in Uw Inst COIUIIlIl indieatp thnt gunyulp fesinous (IIHlnt( wlwtlwr dfircl hi Yn(tlLJ1l1 wilh L~ perc(nt loss of volntllt wutl pr or tWl c1rild giVPd npproxil1lnh1ly t Iw snllw colorinwtCr rNHiing- 011 till busis of aliquot~ cOlllniuiug 2 IJI~ of flsillS lXIHlntp l)tIf 25-mI volultl( Ihil- illdicate~ thl11 Uw UITW IJ1flS~ of olnshytile mntl(f prt~(iJlitnt(d gins npproxilllntlly Uw $1II1l (oiOfirnl1tlf ftudiTlJs ns tho ftsidtw A pnlill1jllaf~middot (XIlltrinllnt indicutls thlli th VUllltill muller l(lIlSists of thl Ilrplne oil fmcl ion I5-(1Il gtnplls or rlsitlOtlS (lxudntll gnvll by stPll1U distillation nn Uefllgl of 011111 of jl(lfPlIW oil with npproximHte tilllsity (If OHIi lind lhus rrprlsll1ll( IlPIJroximllt(I~ 01 Jerccllt Of t he original weight 1hls lllrClnlage complrcs wllh 38 llltrC(ntlost by drvinI( in IICllnllJ
aSplusmnUH perceilt or orlginlll weightlosl
The wailnble illfolJllntioll on tlH (ow-JitlPllts of the gunYllle r(~shyillOllS exudate alld tl1( HeetOlIP ext act of gaylp ti~slw is sllIllmarized in this paragraph lYalttI (u) alld also Hangcn-Slllit lind his coworkshyers 16 reported that 20 percent of the resinolls exudate from gUltyulc stems is parthenyl cinnamaie (CHuOH=CHC020 11JI2r) Steam disshy
15 (OIlIJIIIIUicatioll flom A T Haai(II~l11it llId (0011(11 Calif0111 ill Tnfiitnte of Tccllllology Past(IlIJI Jhps( wOlken al Htud~ing the COTlHlitlllllts of the acetone extract and other conlltituellis of guuyule
30 TECHNICAL BULLETIN 920 U S DEPT OF AGRICULTURE
tillation of similar resinous exudate in the writers laborntory has yielded approximately 4 percent of the whole as the telmiddotpene oir fracshytion Haagen-Smit and his eoorktrs nportec1 thttt about 25 percent of the acetone extract from guayule branches is parthenyl cinnamate and 6 percent of the bark (ltortpamp-phlotm) extraet is parthenyl cinshynamate These workers fm-thcI reported that 25 lwletnt of the nc(shytone extract frolll bLllllches is a compound with the tlI1pilicaL formula CBoH400a 1 percent is a compound llwltillg at 2P to 2T5deg C and 1 percent of the extract from the ]eav(s is tl (olllpoulld nwlting at 100
to 1710 1Valtei (6) reported that 3 to -l perc(nt of the tI(eton( txtract
of leaves and flowering StPIllS of guayulc eonsists of waxlike substances soluble in olgallic soln~nts but insoluble in at(l and (on(ent1llted H 2S04 The flactions mentioned on the basis of (onHLTutle esti shymates of amoullts actually isolated tlecoullted for about H ptIcent of the totalncetollt~ so]ubles extracttd from tll( guuYllle 11 rub The other constituents ltlilaill to be i(](ntifi(d
RUBBER AND RESINS CALIBHATION CVHES
Typical culibndioll Clllves iol Iuhbpl and I(sins bas(d 011 (ldtLminttshytions made nccoLdillg to the plocCdmC outlin(d 011 pages middotb to 1G arc shown in figulPS 5 and 1+ The spCdlopliotoll1lttL en (OIOIjlllctCI readings are plottCd on s(lIlilogalitllllliC pappi ag-ail1st (Il 11IbblI (011shy
100 ~ 90
80 ~ 70 ~
z 1amp1 0 II 1amp1 IL
1amp1 0 Z
60
50
40 ~ltI 30 ~ en z ~ ltI II ~ 20 C) ~ oJ
10 o 2 3 4 5 6 7 8 9 10
RU8BER IN 25-ML VOLUME (MG)
bull
bull
bull FI(lURE 14--Ctlihration curve fotmiddot gllftYlIlc lubb01 (Hct(lings Oil COIPIIHlII tlOl1hl(
monochromator SlCClrophotolllet(r with 7fiO-11IL Illtel alld Hllp Wll ( IHlll()
bull
bull
bull
RAPID PHOTOMETRIC DETE~MINATION OF RUBBER AND RESINS 3]
centrations From a casual inspection of these CUlTes it would appeltr that Beers law does not hold Actual tests indicitted that Beers law was applicable only within a narrow range in the upper portion of the curves The analyticlil results on the basis of photornetric readings nre therefore calculated by direct reference to calibration curves or from reference tables of equivalent values bllscd on the cnlibllltion curves
Calibration curves for kok-saghyz alld heyea lI11tulltl rubbers and Buna S (GR-S Chem Gum IV Goodyear) and butyl (GR-I Standshyard Oil Co Protoc) sYJlthetic rubbers are hOWllil1 figure 15 The samples of kok-saghyz rubber were furnished by the Diyision of Rubshy
100
90 ~I) ()
z 0
1amp1 a
~ a
80
70
60
s 1amp1 ~ ~ 0 ~ KOj-SAGHYZ 0 l Il
50
HEVEA~ ~
40
100
90
~ 0 80z Q 70a Co)
a 60 ~ 0 0 x 50Il
40 ~----~~----~------~------~------~--~ o 2 3 4 5
RUBBER IN 25-ML VOLUME(MG)
FmUIlE 15-CaJiblation curves fOl kok-snghyz h(YCII Bunn S lind butyl rubb~ls (Readings on gy((yn photoelectric colorimeter with i20-lIIp filtpl and 6-ml aperture)
32 TECHNICAl BUIJLETIN [)20) 1 S DEP1 OF AGrnCUIlfURE
Iwt Plant JIl(I~t ignlioll of thi BlII(un and (1( l))(parcd according to 11( SPltI1((-Culd (]] (6) PIO(((lllll Hlpt pal( CLPPe was (xtmch(L with acetone blI()Ieit W 1I(gt(11l a ttnlldal(l
SEXSlllVllY Ol~ llETJIonS
By lip pIO((l(II11P olltlillP(l 011 ]Hlg( +n Iowa (lOOl IIIg (11 1111i(l0shygmm (gHlllllla) of 1hblI ill a 2)1111 yoltll1ll (all )(gt dltpltld Oil tltl Col(man (lohlP mOIlWhlOl1lHlOl l-I)((t 101 l1lOt 0111 ci( I ill1ilnlly 001 mg of Iublwr ill a 2J-1ll1 n]ulllP Illay bl Ilad Oil till EnI)1I photoshyllectlie (O]oLillllt(I Thll ya lllll- 011 tilt IHl-i- (J I (xl ad iOI1 fmlll 02 gill of til-lI tH(JI(lillg to tllP -lllndal(l jll()(pdull 1(PIPStlIt IlO()2J tlnd 002) P(IT(lIt of llIbl1ll IPI)(((inly bull1t1lollgh -lI1t low allils can be d((d(middot(1 il lIoullt1 Ill IPtllizpd thnt till PIIOl ill PlI(Plltng( or tll( al110unt dltlIllIilll(J i ltlatlpl high ill tili PIY lo Itlllgl 111 aetllllllladie(middot Ill( lopl lillliL 111)(1(1 lIw (ollllil ions of tlil ]lI()(lltlIIIl u ol1tlinpd ipt at l11 11I1 or 1111gt11(1 illt i-1ll1 Ollllll IlPIPltPlltillg 01 p(gtl(pnt of JllUiJtL un tlll 1Hli or (xlla ion rlOI11 II rlll of tisSIll
EIlIlOH COSIIlIHIIO
In Oldpl to H(IIp ill )1lHtPltt pl((iioll illlpIi1I- it i lH((SSHI to slnlldHIdiz(i rigidly 111( Pl()((dlll( 0 illdi(ntpd Oil pnglt- - to J( If lids i dOlH tlip lXIHlinwnlal PIIll is t(middotdllld 10 n ndninlllill
Illlt pl(iioll of (hI ]lIPPllt 1IHllwd Oil til basi of ]llllP llIllJt1 alld Ipsinssollltions call hI jlldgl(J 110111 figllll Hi lileh lio- til HPIlIgl d(intioll oft -illgIP lI1lnSIlIlIIIlnt in lHi((lltagl of Ill( alllOllllt 01 Illhshy1)() 01 lpsins d((PI1I1 iJlld TIl( (1101 PlI(Plltaglt H1( gi (1 101 OJ) to
RUBBER IN 25-ML VOLUMEMG) 004 01 02 03 04
i= I I IZCtOW
fbA ICtU CtCt WW a
01 02 03 04 05 06 07 08 09 100 = RUBBER (PERCENT)
RUBBER IN 25-ML VOLUME (MG) 10 20 30
~ I CtZ
bBOw Ctu CtCt Ww o I~
010 50 100 150 200 250 RUBBER (PERCENT)
RESINS IN 25-ML VOLUME(MG) 10__ __3-0_ 40 50 60 70 60 90 100--_-- 2_-0
Ct~ -r- 1 I OZ
WCt UCt b C wCtW
a o I I 150 250
RESINS (PERCENT) o 10 50 100 200
bllI 1tI W-Yllnl dtd1 ioll I I 11l1 11IlI11 1(111(11 1 III Plll- IlIIIlol1 01 IIim~
bull
bull
bull solution Il basis J o golH of tiSSII (JlILCl-nt (11(11) for (~I) (l)1 til O 1I1
of luhllpl lin 1 III I (I Ill of lUhlJPl nllll laquo I J to 111 nlg of IlSlllgt (Itllillgs on ]iYllyu pllolwh-llrk CO[IJlilll(-(PI with nOHIP Iiltlr lIntl U-lIll allcrture)
RAPID PHOTOlJElRIC DELEHlllNAllON Cn HUBBER AND H1~SINS 33
10 mg of rubber anel1 to 10 mg of resins in a gJ-m1 yolumC For
bull
bull
bull
comparative ptuposes the leslllts arc also calculated on the basis oJvershycentage rubber OL tltsills in 02 gllI of tissul As WOlllL be expcet(d the error increases sOIlHgthlf for 1(lali nmiddotly low COlHell t1llf iOlls oj rllbbeL or resins The curves in figure 1(j s1l0 that ill til(gt Illlge Ol to 10 pCrshyeent of lubber the elTOI rangts Jroll1 abollt Ll to II) ]IlC(lIt abo(~ this mlllc tIlt (ITOl d(((ts(s to (ollsidlItbly ltmiddotss (han 1 1lICPllt of tlH mllollnt ltl((Lmill(d Hil1lilally in tlH (lISl of l(sins analysis (fig 10) the ltLTor is (onsit1eIubly INS than 1 PlLllnt ill (he lallgp of 11 t~) ~() penPII t
In nil ([lSl of lllhblI alld (sins lx(Inltpd tIOIl1 (issups Ol addcltl to tisslle lxtlads (s(( tabhmiddots (i H) illyolillg ll01P o(lllntiolls the eLI01
is hig]wl thun that indilHtld in figllll ((j Im pUIl Ill )])p I tllllllsins solutlOII
COlllUCIIOXFOH IXSOLl-IlLl~ Ilgsqgt(Jg
111 th( Jllo(pdulP ollllillPd 011 paw I till illsolllhll isSII Ipidll( tflpl (xttlw(ioll is (Ptill tlw lIask l(lll till xtlct i l1wdp up to yoltlllH It is not rOllPllipnt (0 IPt()PI qWlIltitati(Ir III(lw[olH a 11(1 pllooll extlnlfs of guuyull I is-lll alll thl1l main t11l111 up (0 YOIUllllmiddot bpCaUHI sllch all additiollal stltp wottld]) tillll-C(JllS11ll1illg Th( Iogiea nll(gtIshynntin is to mnkp tltl lXtlUCt Llld Ipsidup lip to OllillH in till original flask andi llPSStllY 10 llwlno tl OIIpdioll wlHIl (allIlnting [hc llshy
Hults f(JI [hl oll111lC displupd hy till ins()lllbh llsidll( III it l)picat (IXpednHllt (ollsisting of Jhp lppJiea(iolls if was Iollnd llftt at ~iiO ( 02 gill 01 Iuhhll pillS IPill-fl(( lisslI(gt (lollpdll fot llwistUlC ou basis of dlyillp ut lOW 101 ) llOlll-j (lbp(ld only t~ llllUll voiul11P of OOk7D~- OO(lOO(i Ill of lllthyl bolnl(yl 1lIOll( (lplhlli(al-t(Tnltle sp gl () Ii I ll(Hli (j at ~)) -gtitllP tl1(gt 1It101111( () r t is-lIl xt Iadld j sl1lall til( PlIOI dul to Ill(gt insoll1blp Ip~idll is slllall III [0111 ill( wOtk it (all lJp diIpgal(ll(l
]hcon~lIY OF HllIllgl AiO HESIS AIH)gl) TO EXTlIACI OP
GlYlLE TISSlg
Tnl)ll G L(IHpslntillp (ypi(nl llld(~ SllOS (hat all a plngl of HIOK PlI((nt ot lltl pltl( Ilhl)(l acldpd to tllP Itll h iolJut1 InmiddottcJllP xhnet
of guayulp tiSI1( WllS 1l((PllIl Tlli nllintioll flOlll (olllplpU I((OYshy
PIY i within flll pxp(IiIlHuttllIIOI ~illli]llly fnbll Ii llows thn 1111 llYlIUgl of 1O(1~ ])(I(Pllt of gllllYllII 1(-i1l- add(d to II( (pllosol( (xshytrae of IUllY]l t i~HI Is 1l(oPIPI
THl~ (~ Hf (Off Ill of 1111)( J OJ I~il~ lItfI(( In ~(JI1IJk~ Ilf (111 [lI1Il fI2 lIII
0 tlUfllllit i~~I1
Instrument
---- ----~---- bull shy 1(1
Colemun ruono~ltrOUlllt()r 2t) II sJl~ctroJlhOL()lIIeter with 2tJ I iflllllI wnclength Fetting 21 II nntl 0-1111 WU HI hUJl(L _ L U
Ill 7Evolyn photo~lcclrie (olor JU [ imctcr with iO-llIl filler IV (I
H1 0 t I I
llImiddot lUn WII 1011 HIO Wn mil lUulon
10 JIg1111 IUI ml lUl anh Io aLn 111)_I ) III li lU It 2) deg wn2SU DD
Irl JIll II IIr II US II
1110(1 lULa lUI IlK) IJ WU
I( llI Htl tNI 1(111 2tlNI HI 0 221) lllil t2S 0 1~ 10 1~13
In (I 2117 I
10U 1l(J ~ 4 _H_j ___
9middotJIlJ5 10115 10 00 lUU5 flUU 4li (tl03 9(11)
leIlKl 1l~)5 lOOU l1KIr JOIS un 003 OIl Ii
34 lECHNlCAL BULLErIN 920 U S DEPT OF AGRICULlURE
COMPARISON OF PHOTOMETRIC A1D MODJIoIED SPENCE-CALDWfLL METHODS OF RUBBER ANALYSIS
Guayule samples were analyzed by the photQ111etIic method and by bull the modified Spenc(gt-Cnldwell mcthod The values in table 7 represhyselltativ(I of typical results indieate It -atisfactory dcglpe of conformshyjty between the two methods in thl range of tiSSlHH with llHHC than OJ) percent of rubbtImiddot On the bnsis of the amounts determimd the results in this runge for the plmiddotts(nt lIlcthod ayernge apploxinHltely j percent highcr
~LAIII~ 7-(oIllJl(i~on of lltlllrIic (IIri mOtllinl SJl(II(r-(ulri-wall IIIrtlwrl~ of rlrrlIIillillfl 11)1)(1 COIIrll of UI(III
1 Flowers frllm amiddotmonth-oltl nursery plants
YAIIIATJO- OF SIli(LE DETEnt1NATIONS Fnoll TnEIIllIEAN
Rllbbel (Uall8i8-Thc plcCision of thc pLcsent method when gunyule tissues Hr( nnnlyz((1 for rubber may be j udg(d flom I Ill datil presentcd in table H TIl(se dahl -how that thl pplCPlltag( uriation of single determinatiom from nwan yullles with low standllrd enolS ranges from less than 1 to 4 p(gtrlent
R(8in~ wWlsi-r-s lndi(a((1 011 page ~j he INntlts s((uled hy the present phoolllttric nsins llHt hod are not tliltly (olllpalable with those of the grtLVimetri( ncetol1l-cxtlt1(tioll II1etho(l Thjs made it necesSllry to selc(t another lalibllltion staudud-tlll Ipsinous exullate from gullyule shrub-thut gies relatively COllstlllt photometric readshyings (table 5) The resin (olltents of guayule roots branchcs or leavcs usually ran(~e from about) to 1-1middot pelcellt The ple(ision of the present methotf WhCll gUHyule thslllS lIe analyzed for reins may be judged from the datalHmiddotpscllted ill table 9 1h(se data show that the p(lcelltage variatiun of sillgle lhmiddott(Lminntions iLO11 meun ynlnes with low standard NTOrs rangcs from about 05 to 4 percent
bull
bull
bull
bull
bull
RAPID PHOTOMETHIC DElEruIINAlION OJ RUBBEH AND HESINS 35
IAIILE 8-luriation inclieute rubller (mallSM of [1wIIle tissue bll thc 1111O0Illclc metwII
Vnrlntlon~Ilbher I (rom mean
ierCtnl Percelll ~OU -22 ~ 25 +27 ~ 20 +18 ~UO -22---------1_______ 51110 0G6 bullbullbullbullbullbull _bullbull
10 ro ----=ii41075 -01 1000 +11 1010 +13
rlln HI itil 1l9~ 1_ ___ =-~~~
115511 ~ US -111 III II 1575 -13 115 b tiS -I a 111 h WlU +22IIM-(middot bull 11K -1Ja Illi c 1000 +03 1J5H1 W +l)7 ll1imiddot tl 1575 -13
Mcnn 15951 131
1102-11 21fJ() +21l102-h _ ~~)SO -17 1102-c bullbull 21CO +21n02middotd ~OIiO -26
2 r~plusmn Il~ 21151 261 I -~-------bull---__ _~~_~______l-___--_
1 lhe$ 1111($ I1n (or SlIlIIllltS Stpnnltplr PHrilClld IIrtlrdlng 10 1hr prollIlIlr( OIiIIiIl(o(I on Imgt$ 4 to IC ~tcond nUlI1 hlr r(J)[ltnts stl1ndnnl llrrot of tilt 1I1(1111
1_1l1~ n-J(lri(iot in relli(Upound rpoundsins (lllalIsfs of VIOJII( lixsue b1 the lhomillric lII(lloli
-- ---~--- - __-------- shybull I I I I Varlgttton
_________~___ ~~lu_n_Jl_Q_~~~_____ ______I__~_o~S_J frOID lDean
Percent Percentgt458-1 ~65 +41IWtl-li 130 -a2Hli8c aliO +26S41i8-d bull 130 -32
1(-011 34I10Olifgt __ bullbull __ ~--====
li-9~2n 881) -06 li-9~2-b Si5 o ~HH2middot(middot S i5 -6$-H2middotd 000 +1
8851 054
O i5 +6 9 i5 +6 950 -20 U75 +6
H-liG3o-n bull -1 n-li6~b bull __ _ -IH-IWH +4H-l61511 bull -1
1tmiddottlU
62~-lI __ 62~-b ij24-( bull OH-Ji
(-Ull
I rll(St oluls nre tor separately ~xlrflCled SllllllllCS IlctOrdlug lO procedure outllned ou pages 4 to 10 i Secoud number r~prtgeulS stulldMd error of lIe menn
36 TECHNICAL BULLETIN 920 t ~ DEPT OF A(]RICCLTCRE
ReUUER A~ALYSrS I~ CRCOE-RcuUER PROOCCTS
Sew rapid photometric m(lthod~fol the ddellllinttion of rubber and reii Hi ill uaYllp ti--ut htp lllell pIPHnl pd oil pag( ~l to In A brief H1111111tlY of It similar rnpid llHthod fm 1I1hb~rllnltlysis of u1lulcanizNl tlIldp lubbll pl(Hlmtlt whielt i~ bn-(tldo on the prill o
ciples dehtilcd tlllLe follows Duplltate nt-gm sllmph of the finely cliyiliNl IlInttlitiup wlirllll out [~ei-()l (all hl lIf((tinmiddotjv INd to lt1iyidl till alllpl) TIll kltolll-olubll portion of till )111(11( tlrc di-olved a- indh-Htpd fot thmiddot lllnkill~ of -tlllHlunlluhhll olutiou Oil Pt 1II hut tIl IUlIp Hn lIn l-fplImiddotd 10 lHI-ml rolllllltti( fln-k antil1ltld(lup to Olllll1l The bnlulUp or till JllO(ldllll i- thatutlilllll on paWs -1- 1 IHI Ii 111( 1(111 1- nIP IXPIP--pd nil til IHi or Iw oligiJla w(lullt of I Ill (I11l1p-I1l11Ilt1 1)(0(11(1
Hupitl PlllimiPJojgtiWllllllllh llIltllOd~ fOJ Ihl llPtlmiddotminntion of ImiddotUlJbll tlnd 1(-illo- ill -111111 Illllph of gutlYllll tiUl IIll dl-eli)ed 111() IlltlY d~o Ill nltlI1lld fOl III Iwl Illhlwl- and l~iJlmiddotb(lLiJlg plant TIllt l[Olllhup hns nlo b(l1l ntuptpl fot IIH lltlIll1illtltioll of lllhbpl ill 11lHhrublwl Pl(Jdlld~ HIIl 1111 hI ndaptld JoJ IIll ann lysis of ynt1J(gt( ic lllbbl[- The llllthmb HIP 1gtn(11 fill tIll fol1owill plimiph- III Grinding
tIll PIOPlly driPl t i~lIl 01 Ul tillg tIll pnHhHt to tll l((lllilllllh~lel of filWlH-- til plllllit qIHlIllilnth( lXIIHtioll 01 IIlbhlI 01 1(--IJl- () llsing oXWllutld olnuh (kttoJls IIt(talp and() fllltil for LIbbel and IH(ltIlIlyptIJllIllIoolYlnJld-o flJllh 101 niJlsl with t(lathelr high IlPililig points 111 to n C) l]olle or in mixt tIll thllt Pll mit tlll rnphllxututioll of luhll(l OJ [middot(ill ill ~() to (l mi1lutp It r(latiwly high 1lllIllllltlltP Ill to 1~11 ) l) lllllipitntillu till luhblI OL Imiddot(ill frolll aliquot () f till oltn ion I IlIlllI-i () f Hlltabhmiddot pl(~(i]litallt (willifhmiddotd lthmwl fOl IIlhlHI Hild llitlifild lllr fOJ JP-illl t~) IIlHkillphotollllliilPIIIIiIlof PlllPlltal of liht tLaIlS mittUl(P lIftlI IlIlbll (II Il in PIlipitalioll 11 II WI( Iplllh thnt (limiJlall till PIIOl dill 10 xtralllOlh (0101 (till dptl1minntinll Iph jill 011 tIll dtwlopllIlJIl of H HIli rOI1ll tlllbidity 111 hpl than I (olot rI
jJlIlpOP-ofallnlyi-I ( p(lllil1thb IIllijOI1ll turbidity or 1llt[lIinmiddotd d(ltl of jgtIp(ii(JlI l)~ lIltlkillU tIl plllltollllmiddottri( ntdillU al tandinu tiJlH~ (dlllilll wlli(h IhlllH(lill-- IP 1llutinmiddotly tnhll) t1ll1t an hlsl~1 oil the (oJlItlIlllItion of IIlhlHI Ill I(ill (lIPIipitat((L
TIll -I(p ill till jll()(Plhul HIP 1-- follOylt (1) 1l~UIIL uJ1lplls of thwl UJfJlllHl (II tliddl(l HUt dlipd 11Illtplial an lXIllltel with11 Ill of till nlnll ill t (oU tlllltIPlll[gtPImiddotatlup oil Iath at 11 Cbull fol 11 minutl I) iIP1lIin(middot(lohd til( (XUtllhllll Jltldl lip to It middotml ynlmlll til( (nlifild by (Illlifllgiuu HlId thlPl IlI nliql1ot of tIl (IalioPlllxUlltl nll Uillltlmiddotll(t to l-llll OIlIIlIllril fiuk- (1) For a trial Ilnditlg 0111 III tlll j liJmiddot~t IllHII IIjI to Ohlllll with lilt Pll shy(ilitnnl a 1(11 it 111 (Dod fill llli lIut ( ptotoJIIltlil IPtlllillg-- of pllllntnl or liuht tlUtllIlillal(I oil n (lpel OphotnJlllllI at rase hng-tlt (If 11 llJ Ill Ol It lollllil1lPtImiddott lloyidld with tIll P10]11 I 1110110shy
Ihlolllltt hmiddot Ii1llI Olllhi lIatioll for -1IpItillg UJlproXilll1l tply Wtl P ]Plwth )0 mp are HHlltk TIll Illldillg lliJtaillld fol tIlt 4-milutl tliall(~ll-
bull
bull
bull
RAPID PHOTO~IETRIC DETERIINATIOX OF R(BBER AXD RESINS 37
ing are referred to a table of equhmiddottllut~ previously p1(pa1elt1 on the
bull basis of 4-minute reac1inJ~ for tilE nmge of lot1telltlatiol1- of rubber or resins to bE elHOlll1t(led tmd gidn thtmiddot -tnnlillfr tillIP fill rUbbEt or resins aiter prE(ipitlltiol1 lwfolE photoIllNliI j(tltlill1 un IUade The r(middotnmining dllplllatt aliquot lll then HHllil up te ol1l1Jle and lpoundadillg ale marle ut the -tandillfr tiUlE iudklltll ill rhl tall1lmiddot for the final r(adillg~ -1) 111( milli1lnm or p(tCPlltllt- of lllhbpL (II 1(-in pr(s(nt are rpadholU a prlpan(l table of lquiltlput for tlll photoshymetric readings h1~l(l ill pnell e1-E on pxpPlilmlItal lhln 1111(1 u-ing as stimtlltlds pure luhbll in 1l1bbtl milllYb aIHI guaYllh ll-ill- lxIHlatt~ in resins detNIl1111lttion I
LlTERATlRE CLTED
(1) lUnSbull 1fl36 THE mURMIXTIOS IIF IOTA RE I III OOl THER llT~II
F1 bullrol IlY U(T1l0fll UfSlfi ~rrnrl r flm lt1 KEYS TI Bill Chern 114 44J-l59 illns
t1 ~ICPHHlObullbull T 1J3bull~ lUTHOO roa THE PtRInCAnu Or a(lIUl IRrIlHU It of TIn
PLRIHEU Htllllflt [ i Bill lallllall 111 Rmiddot 711middotj iIlus
I ) RHBERG P B Ul5 A METHIlO Or ~u(ronrll-nl Hi tIII rUIl[1 f71 ii illlI
bull 14 Hoss W flbull and HARDESTY J O
llH IR1ltDII Of HfITilIZfmiddotR DllIJS ltt 1 Yl fll Off gI bern JIIIlI i ~middotmiddotlf IIl
101 SPEltCE D nnd CuoWELr ~I L 1933 DETER~n-ATIOo OF RtBBER Ii nrllllpoundRBfR Iusr 1uI II1 amI
Em~ifl cttIliIa~~ r Ell i 71middot7i l11 (HI WALTER E D
1U44 ISO~nlS OF PRTlltSrr 1trHpoundV bull l UI n W lHHt (Tnmiddot 1ETS FROM GiYI l~iIl lItr Clttrn SII J UI titJ middotn9--C1 ilIu
17 J YOEbullbullr H lO~( roLORIlETRT 771 IPmiddot nl -W Yurk f H Plrwptric hmica
naly-II rimttry lUll XphHHlnmiddot~ y 1 1
11
HI) ~ fPHELolzTRf 57 111bull Lin xw Yk t H lt PhmeHt CblUlmiddot ila AnaiY~l~-(H lithrry and XIhmiddotILpfIY Y wirh enomiddot rrJlllrjr hy H KtlJnJU11 I
t~1I --- and ~ARVER L 1f41 nlua-w ~in L liLhr IS IP ll~ XIW Yrk
bull For-sale by th~ ~a~fr1nt~nf1ent Dt~c~~ogtnts-~ s t1i rArnn~ut Pn~~~ tJffieshy
Washington 5 D C bull Pl lU ~nts
18 TECHNICAL BULLETIN 920 U S DEPT OF AGRICULTURE
recowry from pUboil(d shrub may be due to the loss of the resinous exnc1ate during parboiling This exudate forms ns It SClim on top of tlw )iquol in the tank
On the basis of t1wse results the recommendation is made not to yaly the nwthoC of leaf lemoYal in any 011( lNi(lu(h project Then fltirly compalabh IcmLts should he obUiined
70 ~------------------------------------------~ LEAVES REMOVED
BY PAR80lLING ____ BY HAND PICKING
60
-I-Z 1amp1 0 50 a 1amp1 a
en 1amp1 gt1amp1
40en gt-CD Q 1amp1 Z
I shy 1amp1 30 a l shyx C)
1amp1 ~ J 20 I shy 0 I shy
10
O+--L__L-~__L-~~--~~~~~ o 10 20 40 60 80 100
NATIONAL BUREAU OF STANDARDS SIEVES (MESH)
FlGntE T-lJiMlil)utiun of l1Ultkh si~(s of gnll~II( tiSSU( JrIOllll(l in a Ball amp 1ew(1 mill to pass six dllIerNlt S(I(euroII 1(IlYes Iemoved from plants by palmiddot boiling 11(1 hand picking ((olltloll dpfo1iatld plants dried to 1I lUoistufl l0I1t~nt (If 01 to o) 1)(ICl1It ground tiSSlli IbalH1 1() minutes ill II ~i$hel
bull
bull
bull Kahn shuk(f
RAPID PROTOMETRIC DETER~UXATIOX OF RrBBER AXD RESIX-i 19
GHl~DIgtiG
bull Th~ entire pant 01 plant l)iHt a~(gt fl r(ll it pllllIIirU1ry lSillg fur J hours ntGi~ C prIOr tD t 1( plChmll1atmiddot rLlmhll III a II lItmiddot or n Ball amp Jewell mill ~n llltllysis of paldch lzP- nftl~l (oar-( IIindill shows that tlwy ar( about tIlt llllH fOl parbojlP(t awl IJllllluhoileu hrubs I fir 7)
The coalilly gloUllll ample i-- thPll Ildlll forI toUtmiddot at ni C afnr which it ha lllilobtllL(gt output of ~ llllut lII hmiddot- dptPlIIlilwltl by drying submlllpil- at 1110 fot hOtll- TIll 1 IIIIll i lltllt lmiddot0l111d hi a IluninHl mill TIll mo(lel uP(t in thi IIIk i 1I Hu IIIOilll mill as IllUllifill bv Hoss nnt Hartlet ( 1 -[1lt111- with n1ll1l1 pldushyrations ittI lilnbhell b rill HanlIolll V0ll11nHiol1 ElIillllmiddotrill (0 The size lutllihl11 iUlJnole So I ( 111m t ~ II t HUIII Xl) ~ I L~ 111m nnd So 4 lillllU1 11 ttllilhmiddotj 0 r tllP Imiddotlult~ p(lln-It willI t11(e Sll((IIiZtS with )arl)Oiltll awl uil)Jtllboiltd hrlll b lOwl1 in fif1l1fmiddot-- This hows t tnt 1middottttIl ~(I 1 llllll (Up jlllilnl IHlt that
r------~-------r--- ~ --r IHAMMER-MILL SCREEN
O~ NO1
NO2 ---shy U NO 3 ---II
I
bull lL
z
r ------ l 30 ~ gt III
i I Imiddot
i ~ I
I 1 I I
~ 20 I - 1 iii 1[ r 10 ~ ~ ~ I _ ~ I r A bullbull
o bull L-~__~__~~__- ~~ 20 40 60 80 100 40 60 80 100 200
NATIONAL BUREAU OF STANDARDS SIEVES (MESH 1
Yutln I i-tlillltiuli Hf pur id lZt f ~naY1l1 t middotnt r1 lI1 i ~ a hatlltlllI 1IIi11 to 1111 Lx IHtllllH middotIn Lt-anmiddot tIlllunl loy la1 litkh~ omrl t 1) tHul parbuih~ -t B ~ thmiddotfuliufptl ]~lahr thpt tu tt fit t 1 It+gtr-tt1 Jnui~tHn eunttlIt _~rnlitl tl~UP ltakmiddot~~ 10 UddU it~ 1 rtmiddot4~pt~middotK1~r ttakt-middot
bull So 1 gingt- 11 tt-liuin-Iy ltr~pl [lPlItl1tat of iilll 11animiddotImiddot- Eqltrimiddot tIlllll hnnmiddot llOWIl dutr fll llltldllllUU xtlutioH 11pound lnhbll lIl lP-ill frolll IolUlIl ~tlaYlllt tl-IlP by dlt IJwtmiddotlUlmiddot lItlilwd oil Ill 14 - 01
i-mllt 11111- -lwltld hi INd I li~ Ii I TIll lllhtIlttj of Itiu~ So 1 (lltll j thnt 11middotmiddot01middot lttwmiddot to amplil tltt Iollllli tilt art lpdnn ib
IntIIll ll~ i po--ihJI with tI lLllit Ilfltl[lll1t It honld l Plllplw izmiddotl rImt ilt tht h of -allllhmiddot with l lllblPl
~ontlnt of ill PPltllt til lIilll it i tlllt pll--ihl 10 11-middot t(1i Xli L
20 TECHNICAL BULLETIN 920 U S DEPT OF AGRICULlURE
Even with screcn No 2 difficult due to rnbbel tlcrltreCtlltiollS may be ob tl
encountered In thes~ caHeH it iH lWit to parboil the shlub fOL leaf lemonll and finally to dry to about 1 to ~ P(l((llt of tnoiibl1(l pound01 b(~t results jn ~rindillp in tlH hanmHl mill
It iH aclvlsable to provic1l thc hammer mill with a ground wire Hillel the presence of static electric (harges 011 tll(middot partkhH will ealls( Home of these to atlhelc to the inside of tllP (olltailWr OJ lila eallsc OI1l( of till pULticl( to form ngg1(llatls EIIolin lalllpling fl01l1 fhis SOI1I(I mlly be (onsi(h1llbl(middot
A1I10l1g the Holnllts with high boiling point that lIlay Ill IlHld in rubber anal)Hs I1IP Illllhyl n-alllyl ketolle methyl ioblltvl kptOIH diisobutyl (tOIH blltyl tHptate llethyl amyl 1Ittail (middotthyl(middotlllmiddot gly(ol diethvl (middotther and n-bntyl (middotthel (labl( 1) TIHse al( also I(sin 01shy
middotent but th( 1(~illS n1( held ill olution by the rll1)bpl pl(l(ipitant tthanol wll(1 lllbb(r is 1)J(lipitatNI (S(ll tabl(s alldmiddotl) On tIle basishyof the lxpHilllPlltH tll( btsf nil-round lolPlli -rol lS in 111( PIlHPllt method is lt1iisobutyl kPtonc wld(h was not IIltlllllfaltllllmiddotd ltIlling Vodd Yflr n A suitable Sl1lgtstit ute iH llHthyl jolllltyL htolt whi(h is l(porhd as llolltoxit UJ)
Clllos()IY(~ (ethykn( glYlol monopthyl (tIH1) blltyl earlgtitol (di(thyl(ll( gly(ol llIollobutyl (ti1(r)~ and acttonylacetOll( may be used as resins sohrCllts (table ] )
In the earlipr work with (sills analysis cpllosoly( alolle was selcmiddotet(d as a suitable solycnt Aitholllh (ell()~oh( alone is pxc(lllnt its rplllshytiwly gwatlL iscosity 1(I(b to bubbl( formation nft(I (SillS pr((ipi tatioll Thi- increased thp (xperimentnl (LTOI OIl of tltp othll I(sins solpnts tI((tollyla((tolH has the proppry of glpatly lNlulingshydH(OSity 11(11 altld(( 10 othr liquids This sohpnt tlHIeforl wa addp( to ((Uosoh( in slIflici(lJlt tlllIonnl to OPI(0111e the dinieulty On the basis (li~ex)le1inwllts ~ purts oi~ a(donyla((tOlll to I puts of (elloshysoh-f (bolll by olume) as Splldcmiddot(l Thp 01 hel Hoh(nl listed hutyl clLlbitol at l(llst the t((hnieal-g1lld( ploduct uSNl is appal(ntly not as good as eithe of t1w ot1(r two () a (ombinatioll of tlWSt
The SOlVllIts JOI liSt in tumlyzing artifkial lubbel$ hy tlw pr(senf method appllLently (lcllIHl on th(middot kind of llI))(I lIp-ityl (Jxidt is suitable Ol BUlla fi and hutyllthlI for butyllllbbl Tlwse reagents IlLe technical g1lld( Calboll amp CtllUil1t Ch(lllilai (OIP This Hllbjp(( hilS not bepn (XtpllHl(ly illwtigated by till WIit(I
PIIECIIIIJ-
All tlst fOl Ih( adlqlJalY or till IHllipitullb ll(Ollllllentillllll11Sl bl baset] on the plctisioll of tllP final I(snlts oiJtairwd with the methods The )redpittlllts s(1e((( n HpJ (xtcllsi( (xp(IimPlltatioll all HatiH~ factor (Hee fig Hi 111lt1 tabItmiddot (jH) Ext(IIin tllts llllTild Ollt hanmiddot shown that H Hatil-gtflltlOIy [gtIpeipitallt 101 1lIbblI is (li-p(IT(middotnt HzHO (c p reagent nil POll sp gl U-lmiddotJ) ill li-P(l(Put (tinmol by vohmlP liol (tllayul( Ipl-gtinl 1l)-P~ITImiddotllt H)~o ill Hl) by ollln( ii lL satishyfaeto7-y l)lp(ipitunt A solution of 1 palt of H~~o to 1 part of H~() (1-1) iI2So1 nnd abo yarious int(lIlIPdiat( proportions of tlllse suhshystanCPs giyp fait 1(511It8 but with till inlIptl(l ill [h(gt ratio of H~S01
~
bull
bull
bull
bull
bull
RAPID PHOTQlIEfRIC DETEMIlXATIOX OF HtBJER AXD RESIXS 21
to H 20 the )olutioll becollles somewhat vbcou5 and precautioll Il1Ult be taken to ttvoid bubble formation When it i5 poured into tilt Cllvettes
It should be lloted that both of these precipitants have an ftellleshymmiddottion It was found that when XHjOH was used in the rubber preshycipitant in pInt of H~~O~ the readings were -table l)Ut were not reshyproJutihk The lIl of XuOH in pInel of H 2SO j ran nHittble result as a llth H(HY(Pl WIWll til( li-P(l put lthatgtl in lublltl llnalysis or H~O illlP-ius anal)j wn-i uddint(1 thl eharalteliti(s of till liquid with pleeipitated ruhber or resiu in HI~P(ll-ioll n ren1 on the lpNmiddottroshyphotometel m tololinlPtprfollop(1 it lPgnlal lIlll II~ lxplaiHd on pHgP-I (Sl( figs 11 aIlIIl) Tid made it lloible to outain lEPJOshydlHibll tpnlt nntI (onplt1J1(Jttly till JpqnitPIl tlPgJPP of PJPcljoll
IIWIE(TI 1lt COl~101J)
Jtl thp ItJiPl middotxlwlillltnb hefoJ thtmiddot -1l]YIlIt allll pnmiddotdpitallb had lIptll ptoppJly adjutp(l it l fOllll tIuH till llP or a Ploltiw colloid -wll ltIi1)cJ [ttlJmiddotntl- imlIopl tll lmiddotpro]lIibility of the lPlllt JmUkllly ()Ilt 111 U lput lUlU illlihumiddot tOJllPOlUtl tpHd liglyeol teltlut( - llpanlItly IllmiddotlfP(] to lit til I1m t IHflll lImnnmiddott nftlr tlH filial prOIptlllll WtlP dlvPllill1 tlll 11lIlpfit (If thtmiddot [llltlltin lollohl wa Hot 0 natlv I1l(lhmiddotd III rlumiddot Ia- of tmiddot ill tllmiddottJmillaritlu it b [1 hmiddotjlmiddot til IIpoundgt Ir llH1 It liltr ill-llImiddottiT Ina lll ptlPII by it U( in ruhhfl mmly j 11If dtmiddottail fOJ tltt lllllmtlllll If thl plot pet in nlloid ~llntill tltlmiddotlImiddotmiddotlttlatiflll lIOlllllllhtiPI1 are iPllllll page
liTFHFEHliG COIOf
(hi II tht lllail 11111111111 that had til ill -111111 II urklll) om tlH method fot lublJtt tlIlO1 rpir- nlalv~i in plaut llllpll- wa ttl (lilll~ inare tIte (gt1[01 till to tIll ptP-PlHt f xi [aIWIIII- 111 TIlt amount of (olor varip from lUllIt tn -amp ]pplwHlI nlt rhmiddot lt IIf thE Hl(ltllial tllP part of till plllIt -lI11lhmiddot(l tilt hi-tlllY f tlll plaut mtteshyrial ~ub-lltInent to Itlllmiddotnmiddot-rill lliI 1011middotly OrllPI Inlw
In ruhlwr lrtl-i I Iii 1101 au Itmiddot 1Iplll11l by 111[ I--r ratmiddottilt thE -lllll]t with uptoIw or 1middotmiddotlIll-ol - wIdell [llllol- rlll loillriu nutttel autI thtmiddot lpill- Thi- howmiddotvt n(tnll- til lXtla -11gt1 ilt prlJ~edun) In lP-ill ltluay-i nllHufldy tlW[t j 11 1 1IO(PIlln fill the 11shylImya of hlulophyll Hwl rIlI-r middotIOII IHlttlmiddotJ dlH lUtl~ In plltIH withoUt alo aiftIriL till nmiddot ulttrll
111 pllIbIll1l Wi tilmiddotr hId h It-ImiddottHI tht Pltlpll 1 hlitlt lilt tlw tulllWlli tollImiddot uIwltllIIntut -lltUIhorlllllltll 1111 tIll tlettlllliIttwr IIf t 111 lWlrl-Uamiddot of bdt tl11blLlittUhmiddot r [1 tItmiddot preshyj
lipitatifll 1lJ llllllWI atbull 1iI- in III -1nrmiddottIi fHlttalldh nlrillU~ amount rf middotlorilig lIUlttll Iii lhll of ih lltmiddottllllhottohttt~l l~ol()r infrtl Hm II upd 1 rwmiddot tld~middottilmiddottll PlllItlhi~ f it j proYitiltl with tIll lilP--UlY tU(jlIdlllIlml tIltmiddotmiddot lllklllUIlI
EIECTIol OF 1 [EGTH~
-Ptfmiddott ral tracilull ru~lI gtIll fr 1 nllb t ~xtltd 1 lIlt-th vI iobmy1 ketommiddot lWtl rill [ Ixt lttltt ll UttollylaIiIitt1l11I1t~ ~-I itoiu YtHil)u~ typp of ~IHaylllt f i lItmiddot art hraquoil ill fio1ll1 ~l Th~ lp-nlt fill I11oohl uio[1t ttl willlr til tltN- fur rht IUiXtIUt iwliutll
100
22 TECHNICAL BULLErIN 920 U S DEP1
90 bull eo
I shyz 70LLI 0 a LLI a 60
LLI 0 50 z
a ENTIRE 2-MONTH-OLD PLANTS~ 40 b ROOTS AND BRANCHES OF ~ 3-TO 4-YEAR-OLD PLANTSen z WITH LEAVES REMOVED ex 30 a C CURRENT-SEASON GROWTH OF l- )-TO 4-YEAR-OLD PLANTS
20 WITH LEAVES REMOVED
d LEAVES FROM 3-TO 4-VEAR-OLD PLANTS
10 A
0
a Cd 100
b bull
10
80
I-Z 70LLI 0 a LLI 60a
LLI 0 50 z ex I shy 40 ~ en z ltI 30 a I shy
20
10 B
o~__~__~__~~--~--~--~--~----~--~--~ bull350 400 450 500 550 600 650 700 750 BOO 850
WAVE LENGTH lM~)
FJGcm O-Sll((middotlllll tramaniW1IHl (mrpS f(JI (xlmll 11011 n J1ll of jlta)nle tissur ill n 2--m1 Y011111P of (A) Illrthyl ji1I1J1ltsl krtonp 1111(1 (ll) nt(middottQnyla(umiddot tClIc-C(l1osuln a-i
bull
bull
bull
RAPID PHOTOlIElRIC DETEH-UXATroX OF ntBHEIl AXD HEstxs 23
ThE dula Pl(S(l1t(lltl indi(ntp Ihut 101 Illp ulimls llHthyl liohutyl htOlIl (lxtrHts (lI(I r(dolls of Il1Hxi11111III nigtol]gttioll wiH1I all (is-lIb 11 cOllsic1(]((l n1( blhn(11 wn ( ItIl( Its lIO to () I1It~ nlid Ii to Iii mJL
WhllNIS tlw I(gions of 1middottnL(s( light 1lnlllittamp al(l lgtPlW(PIl wan Ipllgtltsnr) to Ii nllt jW) 1I1JL nlld alio Silllill1l 111l1b (n SI(lIlId 101 nc(ton ]altmiddot(fmiddotollp-(llloolp ~ pxt Ill of 11a 1111 t illl TIl( (1101 du( to lolo ill tlw litlltitl a 1Il1 lullll(I tH lPill- hanmiddot bpllI PI(_ ipitated ma he 1((I1((d to fltI ynbhing poillt II ph( illg OJ illshylmiddotJall(( WIWp balld nhm ()) IIIJ1bullbull[1I111 lxjlPIitllll1b Illln -h()1 that Ih( lIIot uilahl( WHYI lHlIJ fOI 1-1 ill 1l11J1l(I HIH11Pill- illllllrsi i-in till IlPighl)()lllll()(l of ~llIl1lt bull
bull UIlIilHlIy of n typhn] lXPllillllllt to )10 l1iP(tiP ((JIlllo( of (ItOIS dul to lOIOl in 1llblnI Hnd Iill xtnumiddott 11(11 IIIIolp t jUl i p1llelll((l ill tub]lL Till llhlllt- 1tpIO]II Hnd ((llll~()h whit-h UI(I ](]Hllilltl n 1I01lllIhb1 01(111 lxt 11111 IIll 1llll)1 nmtp[in I and )(middotills Tid IIlnkl it poiblp nftlI tlIp uplll1tillll or tlll o1PIl( (0 [niH lip 1Iidl1p~ of lI111 11111(( ill lit ll11l1)[1 (llnlIb nlld Ihll
Sl(ll n ol1lliOI with tllP olnl IJllt illiollt HIl Iltlllll llllI (Ill ltllthpl prpipitnnt j Ihll1 nddld OUI ha a lIilPt lP( of till lIiciPlw of WH( lllIgth 7) lUI- ill llilllillatiu (nnl till tll Ixtll1I101l ()lll~
Tuu tmiddot-Elilll IJl flrldillY 11-1111 lrlllI IjfJI til islII 1 1(1 ([rllt IIIIIJIlIr JiIlIt~ if 1Il( Ihll 111111 k til I III Ilrln I 1Intd tf 11111 JiSf fill I I II I tIII Ilf Iilltl 1f1JlIIillII1f I Till 1[ 1 IId 1 (I (middotIt 11111 (I1I1iI1 1lf1IWtlfJlIIllfflr p middottrllhIJ11 II J III 7IImiddotIa 111 111 lilt jJIp 111 wilTII
t~t tnVIli~ ~nn r kn t~ i tmiddot ~~l Jr 1middotmt ltlTt
HmiddotOtt ~I~ lin t I ~ 1 t~~l ~qrmiddotthtmiddotrtwb
Hult-middottltlru t T Hw ullut rHtt~ r II I ~ PH~lllt
A~tmiddottHHjmiddott~rjd rl ~gtllh 1 tn~th~ ~ ~ middotI lt~ b w bull hmiddotth~ 1i~lIhun 1 Ii tnl Illd1 -11lt1(11i lullI lUI tJl ll~ t1~11n( I Ihan1li flfttIJir Ult I Uuhtltt ahuul l(hmiddottHmiddot~t trv r fti HIt lftbyl tlonhUt)1 k_hIl( 2 m~ fmiddotf tuhlHmiddotr In mlth~ llmiddotlf- 1 t r
t r_~ t j
Arhlitlltd ~llIIDHl NcWitn1 ( Ar-(lt()nc~middotttrrtrt ritJJI~ -Iu nllJtl4-middotr
ACtmiddottflnp fmiddotxtrn( ~ T-P511ftf tn mtmiddotth~ 1 ~difmiddotut~ kdn 2 nltt ulruhhtr in Un-tIl lltbu )J~IYt
rUth(Hl~hltlft HhubU
Illlh(I(t tttUtUt hUbtl til J ~jlitl(J Hilllll trtIIImiddotjtl1ll
(UShl I ~tlO wHllolH rulh r (middot1111$0]( J~rru t t )lthyl 15bullbull1middot1101 klll1l
Ili( UHUicbcul ~((i1rUtl ~ulu1iin 1middot lIUIll Ilti lrllltlllt I Ruhhr llt1thuI r1 -1 Irld
ltlt1111Sh 2 nuz f)rruhl~rm nlith~l tu- h f nt nil~middothgt(H] tlrlftmiddot 9lUtirtl middot1 1
rlcltfl( H(l dnllltml it
(IISllhH~rI( Iultruhtr CII05 1v ltTlft I 2 UI~r ublwr In llldh I hlt~1 11) lgtjdvr(llsl~9rlltmiddot middotlmin ~ I~ gt AIHItilltl no IrttipHallr iI
~ Bbnk 10ol m(thyl i~tmiddotut~i kdHn H 1 m1 j~~ l1rH-t lt~tlfltmiddotn sf n it ll HltlMjftr~nol O2~mlJ ~U~1o-ulp ti~tW -xtra~middotl(lt1 ltt 411 ml bull ie f Ct- kft rt t~ tirattJ middott ill r u l1kn ttJt
in metltl isobutyl kNqnf nn~i mljp ur tmiddotmiddot ~oml ~urr tttl i t w ltJj1JH kt 4t 3 nlank 1 mL((l1t~rthmiddot(middot mI mttr~ ~but a kmiddot tmiddotc d 11 ~ gtli~b~ hifIAft- fl~ lL lnti 149
ml8(dlfilll BO bull 02 gm guayule U$Stl(middot xUlClt-l tf(h tft wI n nmiddotmiddotmiddotlgt 1 lznt on tmiddot ~Jt r~1 ~~u~~ H~ iI~ thT
24 l$CHNlQAL BULLETlN l20l S DJltJPT OF AGHl(CLlOHJltJ
In table a is pl(sentc(l such c1il((t edlt1tIHC showing that thc (0101 Ixtrnetccl from guaYIIle tisslIe wit h II(P(OIl( n nd (pl1oso[yc is cll(div(ly sCIe(nec1 out by the s(lp(tion or wnw length )0 miL Oil t1w SI)((IOshyphotonwtpl This tnb]p all-HI ihos thai thl Juhlwl altl(l((1 (nn IJl quall shytitntivcly 1(I(()(Ipltl in tIlt PI(ilIH( or Ih (o]OIplnwPIials and Illsins and tlmt Iuhb(l WtlS nppnlllltly 1I0t (xtltI(((1 110111 11l glll1I1l lisslIt b~ tlHSP SOhlllts Thls( ((suIts ginmiddot (OliIHillg (idJt(( that t Iw IISI of waYl llngth i)ll 1Il) OIl till SppdTophot OIllltPI ii t hl 1101(1 p(oshy(ellule in photolllliTie IlIlalysis of luhhlI OJ l(sin-
SELEGTIO- OF )IOiOCUHO)IAIIC ItIIm ((1111110
On th( basis of th( IPHIlb shoWIl in tabl(l 1 al hlllpls (1( IIln(lp to SPCtl lC the PIO]Wl 11101lO(lIOl1ln til Ii ltlJ ((lIllIJi nIl ions 10 llIiOlS (oIOlimet(Is 111(gt 7W-Ill~ filtpl flllnhwd 101 til( I1~lI1l photoshyplpct1i( (o]oriJl1ltll fol which Ill( (hlll(IlIiitit~ oj t hl Ilda he light ilUIlBlIIhiSioll (t) elll nn -hO11 ill fig1lle 10 iws satlsfa(lolY IPshysultl 111( iiO-mL HitlI olllhintioll 101 whkh ttp (middotIatinmiddot light tlnnsmission (ullmiddotis a 1-0 showlI ill figllll (I is -nthdnlto1 hut this is not stnlHlnld NtllipmPlli
Up to fhl PlPHllt lIS(middotflll pound11((1 (ulllbinntions jn lltl iOO-I11L Iunge hayc nol bllll SlClIlld 101 lhp Klpt 1-1I1l1I11PISOIl (olOlinwtll bu fnltlwl nttCl1lpti 1( )(illg IlIHd
TJIpound OF ST~lmW AFTEH HIIJ1EII Oil HHSIS rlll~CIIITTI(J
~ considl1ltiol1 of ttp lillll of Inlllling af((1 plpeipital ion of 111gt)(1
01 l(sinSTlOIll ollltionis impoltant J(jl~ thC1HI(Plltngp of light IInIlSshy
11 rshy10 f shy
09 f shy ~750 Mil- DOMINANTI
~ 08 cshy I WAVE LENGTH z
I III III i O7 - I III
~06 - 05 shyw
a
Igti= 04 - 720 Mp DOMINANT ct WAVE LENGTH- ~ 03shy
02 f shy
01 t shy 1)O~~~gt~- J 600 700 800 900
WAVE LENGTH (Mp
bull
bull
bullFIGlRt IO- COJllPIUlItiw ~IW(middottltll tlnIlRlllii-lion (II (IllP( 101 1i11(1 olllhinulloll
with dominllnl Il(lllllgths at 720 and 7iO lUi
bull
bull
bull
HAPlD PHQTQlfE1IUC JjETER~lINATION OF Rnmrm AND HEtiINi 25
mitted (spertrophotoll1eleL lCuding-) Ol light (1 (tClcrl (phOlOshyJluol01l1et(L lcndillg~) i~ StlhjNl to (hangl
]fjt~l1le 11 and l~ show that ill til( (asc ot tJaugtIllitteltllight llJHC th~ (x[llliHlllIlnl (oIHlitiOllS tllpl j lilst n dtlln-e ill Pll~(lltngl or UllllslllittnlH( follrnY(l by It ptJiml of lClntin stability with only sliuht (1111 tHn- a f(Pl a lIt1ll1btJ of minutes The light t UIllllitblllll t l(1 ill(Iln~(s This lIIay IJP llllllJltlli7P(ll1 ffl II ow 1Ilt )( f(( darI oliIII tIIlIlNlIlitt(IIIlfJIIlh (iditilIiid Ilil1 pllIipintnl )uoshyIn Of ( 8inx in (~f1( I~iUII i~ Ild stahl I 11 itlll If 1inl nh prlshyilli(ioll of 11l1d(1 II IJIX f) jllIli II (fJJltfiIIlilty slllMI IIriot 1) IIIPldUnl1i tll(I1I rllltltilJl oj tJi~ Jlt jiot IUN ilUf Jxl1 will tIt( tOWI IItlllilil I 1llIlllblJIol I ill I~11l11111 d ill till ifjuids JjOI scnttplltl light 011 till phololltHJIOIl1lttl till dilPCt ion 01 elangl b tlw IPrfIi (If that illrli(atPll rOl tlulll1Jittp(lliuht It Itlll b( llluliJr I-(Pll that if l(middotndlnJ- IIIP mad n itl I t lIP ~()ll1d()lb lpalll this pllioJ of nmiddotlatirp tuigtility tllP llLot tIOllt thi Olll(P (nil bl IPdUCld to tIl lltini III 11 Ill TIll l~adiltg (illH~ bbll Oil tlHl datn rUl lublwls and llsinlt Illl ginll ill tnhh
50 r----------------------------------------------- f shyZ
~ 40 ~----~W~A~V~E~LE~N~G~T~H~7~5~0~M~P~~~~ ~ --------------------=-=-= ~ 30 f- WAVE LENGTH 540 M~ _z _____ ___ -=- __ _ ~ ------shyt ~_=---=-=--I GUAYULEIII 20 -Z HEVEA ltt II KOK-SAGHYZ f shy
4 6 8 10 12 14 (6 18 20 22 24 26 28 30 STANDING TIME (MINUTES)
FIlirtn 11 Emmiddot of wav hll~rh Il li~ltr tlall~lIIit1alHl aftI IUIlItHt -Imlli lug 111m for guaynh llmiddotn 011111 middotiolIlJh~z 1111111 llijlitul1 flolll 1lHlh~ll1Jllryl k11II11l ~(lilltlll h~ lwitlitll 111Inu1 111l~1It1 2)1111 o1U11111 (Helillins on (illllun tlunhll IlIIJlllw]ntllW111 lutl(I[lholtllllltlt with ijUjt Wlnl IHI Ilf1 I
11 EFFEGT OF Hbli 1 -()JXT10~
Tilt lnblwl ~()h(llh pxtnl( till IPillgt ubo It 1m nllu1- bellt -~atea thut ~lll 11-111- tUP olnbhmiddot ill middottIIlIlOl ~1It tlWIIJI( my U)t PIl (tlIHatcl WIth tl1l lullh(t I tahle lJ 1hln 1- -1111 tIll (llllstlOll of nny p()~iblt tITptt of XtIIl11 diflp]lws ill ((JlllPllttUliollS of 1l-in lil lolutioll alollJ with till 1lIltbpl TIU data ill wbh +ho on tIl( hn~is of (olorilllPill ladillU thaI tll( IIUOIl1t of lnbbll Plllipirntld 110111 Ilwthyl olnlld kptOlll olntioll IJ 1li-jHlllnt 1l)04 in 1-llltlIllt ethallol)- not amlll hy thl llllNlI(l of llvin aU1ouut of llins inolution bull
-----
26 rECHNICAL BULLEfiN 920 U S DEPl OF AGRICULlUHE
100
90
80(I) C)
z Ci 70 UI a 0 60 a ~ UI ~ 500 ~ 0 I Il 40
30
A 20
0
100
90
(I) 80 C)
z Ci 70 UI a 0
60a ~ UI E 0 50 ~ 0 I Il
4-0
30
B 20
0
--
--shy ---shy---
2 4 6 6 10 12 14 16
---shy= ~ ~ shy
-
2
025 05
10
15
20
25 -30
35 40
SO
-60
=70 80
16 20 2224 26 26 30
OS
- 10
IS
20
2S
30
35 40
-50
-60 -70 -80
bull MGPE 25-ML
VOLUME
bull
MGPER 25-ML VOLUME
Florm 12-EtTld (If till1l or Slllldill~ 011 light transmittallce (01 (A) gUllyulc lnUIl(I plccipitllitd frOIll llltt h~l isobutyl Ielollt solution Ily neidilic(l ethanul bull null (B) gUllyule ll~illii pre(ipitated flom aeltoll~lllcetOlll-Cl])osolY( 3-7 solushy11011 by H(illilip(i l1U (HPlldillg~ nt -lIlillult Ifllpluls 011 Evelyn photoelectric colorimellr with jU-lllp tlllll alit U-1I11 npN(lle spp also table 2)
bull
bull
RAPID PI-IOlOMEllUC DElEnMINAlION OF RUBBER AND RESINS 27
TADIbullbull ] 4-ReZation of amiddotmount of middottbber pleeipitate(Z Oln metltlIL isobutyl ketone 80lutions by OS-pereent H 2SO in 95-pere(lIIt ethanol to umollnt of resin8 udde(l U8 indivute(Z by colorimetrio readinU8
(Rubber ami resins cnlculntcd on bnsis of amounts in 5middotml ullquuts of extract from 02 gm of tissue in a 2fllll olumo( bull
Hubucl r~cocrell whcll rcsins nddcd as IndIcated Htbbor al1dcd (pllcollt) ---shy
__________bull_________ ~_12rpcrc~15011crccllt 7511crccnt IOOpcrcent
PerCtllt ercellt Percellt Percellt Percent o o o o o) 50 250 263 252 25000 500 500 500 500 700 750 750 751 749
1200 1250 1250 1250 1250
EXTRACTION TEMPEHATURE AND TIME
Typical experiments to detllmine the time required to secure maxishymum extmction of rubber und ltsills at 115deg U Ilre sUlIlmarized in figule 13 the solvents used-methyl isobutyl ketone for rubber anrl Ilcetonylacetone-cellosolve 3-7 for resins extraction-are very eflicicnt since under the conditions indicttted maximum values were secured after 30 minutes of ext1llction The most eflicient liquid for the bath (lig 1) used in extrtlcting rubber or resins is ~ high-grade cylinder oil (S A E ~O) The sand bath and such liquids as glycerol have proved unsatisfactory
RUBBER AND RESINS STANDARDS
According to the National BULeau of Standards 1-_ lhclc Is no gellcrnlly recoglllz(d standard lIIutcrlul [ior II rubber standard] The rubber hydroCllrbon ill llifferent samples of conmlcrciul smoked sheet or pale crepe from heclI pluntlltions nries from l~ 10 04 llercent of the totul nutletmiddot the most 11Ioruble conditions Of preparation
McPherson () has described a procedure for the pLeparation of pure heve~ (Hevea brasiliensis (H B K) MueH Arg) rubber from crude rubber or latex In the absence howevcr of ~ generally recogshyn12ed stalldard for rubber hydlQcllrbon [caoutchouc (CnHUs) xJ the standard adopted was that of the relnthely pure product secured from gunyule tissue txtractiotl nccording to the Spence-CaldweU method (5) or the motlified PIOCCdUlU of Hohnes lind Haasis (p 2) The details for constructing the calibration CULes are given on page 10 Standard rubber samples apparenl-]y can be stored for a long timc under the conditions des(libed on page 10 The duplicate colorimetric lendings for glULyule rubber newly extracted by the modified SpenceshyCaldwell method were ()J2 ench as compared with US) each for the sample extracted by the same method but stored 1 years In each case colorimeter rcadinllS were made on mixtures containing 2 mg of rubber in It 25-1111 Yolume
The selection of tt suitable standurd for guayule resins presents some dilliculties Tll(~ acetone extract of gUllyult estimated on (l gravishymetric busis~ for instance proved to be variable depending on the type of tissue sampled or season of sumpling because such fractions as
COllllllunlcntion dul(lt1 Octohtr 22 11H3
28 QECHNICAL BULLEQIN 920 U S DEPT OF AGRICTTIIlURE
16~==========================115 shy
14 bulli= 13 z ~ 12
ffi II Q
10 c w 9a w
8gto () 7w a
6a w
5en III ) 4 a
3
2
A 00 5 10 20 30 60 90
14~------------------------------------------- bull13
i= 12 z w II ()
a 10 w Q
9 c w 8 a w 7gt o () 6 w a 5 If)
z 4 If)
w 3 a
2
o+B~~__~__~____________~__________~ 5 10 20 30 60 90
HEATING TIME (111 NUTES)
lllGUltE 13-lDffect of time o( lICntillg O2-gm samples of gunynle tissue with solYlIt nt llfio C on lo(OVl)ry of lllhlJer alld 1Isim Lt HlIhblL extracted with methyl isohntyllwtone B resins Cxtll1cted with aCftonyla(etonc-cellosolve 3-7 bull
chlorophyll are weighed along with the resins in the acetone extruct but are not estimated by the present photometric method (fig 0) 1he use of a diffeJent stanclttrd waS therefore indicated
bull
bull
bull
RAPID PHOTOMETRIC DETERMINATION OF HUBBIm AND HESINS 29
The resins standard selected is based on n relatively pure source of resins the rcsinous exudnte 011 the stems of guuyule plants IJldimishynary expeliments with the resi nouS cxuclate from diffcrellt gllayu Ie strains of various ages indicatc nHlt there is little YaLiation in this subshystance on the basis of Colorimct(r readings 011 2-mg aliqllots of 01shypercent solution in It 2i-ml volume (tabl( li) Expelilll(lnts have shown that the air-dried (xuclate contains 3RtOH p(Ic(nt of -volatile matter This material is l(latiyt~ly stablp ill (OlllpoBition and is npshypurpntly on ly slight ly hygroBcopic as shoWIl ill Ia bl(1 1 Tlrp Ipsinolls exudate may be jJleplpd in two wayi-i fl liSP as a stallClHld-(l) the clpan exudate is clripd iol Ghouls at ()1deg C at W indlPs of a(lIum Hnd aftclbCinOglOund ill a molfalis 1)I(spI((I intn airtight COllilinel OL
(2) tllP Cx7lclate is clissolllt1 ill a(lhllll and filtplpd PlactieaJlyall of the acetm1l is thpn lYapolntwl olt OPI a stlam or atCt hath and Ow residue is dripd ground an(( PI(sPIld as ill tllp fin lllethocl Tlwse two prepalHtlolls a1( (ompalpd in ta hlp ) 111( (((tails fOl ~t()lil1g the resins standald and (onstlllcting the calibration CUITPS alc given Oil page ]2
lAIIIg fi-CUIIIllrsoi (lJ lIr-dr(1I IIIIi 1((11 II II-()I-tr((l l(sil~ 11111111(8 of I II 1111Ie
[Colorimetric rrndill~s 011 1~I11 phulll(Iclrie eolorillJct[lr with i~()middotmll (100- to iiOIIIIl) fillcr [lnd 5-1111 lIperture preeipitantl part ofO5middotPIrctllt 10 to 5 paris of IIOj
nupliclllc(oloritwt([
nIl(lin~s (hIlSlcAg~ ofSlmillXo JrNliltlCllt of fPsiJI$ L1Xtlrlntp on 2 IIIg ofplanls fllsins (XIHIIlt~Jwr 25-1111 vol
tII1(1) 1
leflTs Various _ bull ____ bullbullbullbull 3-9 Colll)Josiltrlairmiddotltlricfl bullbullbull nf)2 002
])0____ bullbullbull _bull __ _ bullbull ~-l Composilld (ri d at n5 C in aUmiddotimh lWUUllJ for l (jOuj(ja hours])0______ bullbullbull __ bull ___ bull 3-0 COJIlpositld disso]NI in neptolll f1l1erNl fl(lf()ll( GGO i(jO (Ivaporntld olT OV(1r Stpl1l11 halh TesidlH drl(ld I1t fi5deg ( ill anmiddotinch VIl(Unlll for 0 houlS bull
middot106 __ bullbull _ Jir~c1rild_~_~_ _~_ ~_~ _ ~ ____ _ __ _ OUu GOifina_~ ~ _ ~~_~ ___ _ _fln~ ~~ ~ ___ ~ __ 6(imiddotI tiliA H)[_ ltlu bullbull i18 tisSflOabullbullbullbull__ bullbullbullbullbullbullbullbull lt10bullbullbull _ tillO llitO406__ bullbull __ bullbull __ bull __ __ lt10_ Utl2 fon591_ fo__ bull liGa oOa 406bullbull _ __ lt10bullbullbull_ li5S OM
j Ph( vnluls in Uw Inst COIUIIlIl indieatp thnt gunyulp fesinous (IIHlnt( wlwtlwr dfircl hi Yn(tlLJ1l1 wilh L~ perc(nt loss of volntllt wutl pr or tWl c1rild giVPd npproxil1lnh1ly t Iw snllw colorinwtCr rNHiing- 011 till busis of aliquot~ cOlllniuiug 2 IJI~ of flsillS lXIHlntp l)tIf 25-mI volultl( Ihil- illdicate~ thl11 Uw UITW IJ1flS~ of olnshytile mntl(f prt~(iJlitnt(d gins npproxilllntlly Uw $1II1l (oiOfirnl1tlf ftudiTlJs ns tho ftsidtw A pnlill1jllaf~middot (XIlltrinllnt indicutls thlli th VUllltill muller l(lIlSists of thl Ilrplne oil fmcl ion I5-(1Il gtnplls or rlsitlOtlS (lxudntll gnvll by stPll1U distillation nn Uefllgl of 011111 of jl(lfPlIW oil with npproximHte tilllsity (If OHIi lind lhus rrprlsll1ll( IlPIJroximllt(I~ 01 Jerccllt Of t he original weight 1hls lllrClnlage complrcs wllh 38 llltrC(ntlost by drvinI( in IICllnllJ
aSplusmnUH perceilt or orlginlll weightlosl
The wailnble illfolJllntioll on tlH (ow-JitlPllts of the gunYllle r(~shyillOllS exudate alld tl1( HeetOlIP ext act of gaylp ti~slw is sllIllmarized in this paragraph lYalttI (u) alld also Hangcn-Slllit lind his coworkshyers 16 reported that 20 percent of the resinolls exudate from gUltyulc stems is parthenyl cinnamaie (CHuOH=CHC020 11JI2r) Steam disshy
15 (OIlIJIIIIUicatioll flom A T Haai(II~l11it llId (0011(11 Calif0111 ill Tnfiitnte of Tccllllology Past(IlIJI Jhps( wOlken al Htud~ing the COTlHlitlllllts of the acetone extract and other conlltituellis of guuyule
30 TECHNICAL BULLETIN 920 U S DEPT OF AGRICULTURE
tillation of similar resinous exudate in the writers laborntory has yielded approximately 4 percent of the whole as the telmiddotpene oir fracshytion Haagen-Smit and his eoorktrs nportec1 thttt about 25 percent of the acetone extract from guayule branches is parthenyl cinnamate and 6 percent of the bark (ltortpamp-phlotm) extraet is parthenyl cinshynamate These workers fm-thcI reported that 25 lwletnt of the nc(shytone extract frolll bLllllches is a compound with the tlI1pilicaL formula CBoH400a 1 percent is a compound llwltillg at 2P to 2T5deg C and 1 percent of the extract from the ]eav(s is tl (olllpoulld nwlting at 100
to 1710 1Valtei (6) reported that 3 to -l perc(nt of the tI(eton( txtract
of leaves and flowering StPIllS of guayulc eonsists of waxlike substances soluble in olgallic soln~nts but insoluble in at(l and (on(ent1llted H 2S04 The flactions mentioned on the basis of (onHLTutle esti shymates of amoullts actually isolated tlecoullted for about H ptIcent of the totalncetollt~ so]ubles extracttd from tll( guuYllle 11 rub The other constituents ltlilaill to be i(](ntifi(d
RUBBER AND RESINS CALIBHATION CVHES
Typical culibndioll Clllves iol Iuhbpl and I(sins bas(d 011 (ldtLminttshytions made nccoLdillg to the plocCdmC outlin(d 011 pages middotb to 1G arc shown in figulPS 5 and 1+ The spCdlopliotoll1lttL en (OIOIjlllctCI readings are plottCd on s(lIlilogalitllllliC pappi ag-ail1st (Il 11IbblI (011shy
100 ~ 90
80 ~ 70 ~
z 1amp1 0 II 1amp1 IL
1amp1 0 Z
60
50
40 ~ltI 30 ~ en z ~ ltI II ~ 20 C) ~ oJ
10 o 2 3 4 5 6 7 8 9 10
RU8BER IN 25-ML VOLUME (MG)
bull
bull
bull FI(lURE 14--Ctlihration curve fotmiddot gllftYlIlc lubb01 (Hct(lings Oil COIPIIHlII tlOl1hl(
monochromator SlCClrophotolllet(r with 7fiO-11IL Illtel alld Hllp Wll ( IHlll()
bull
bull
bull
RAPID PHOTOMETRIC DETE~MINATION OF RUBBER AND RESINS 3]
centrations From a casual inspection of these CUlTes it would appeltr that Beers law does not hold Actual tests indicitted that Beers law was applicable only within a narrow range in the upper portion of the curves The analyticlil results on the basis of photornetric readings nre therefore calculated by direct reference to calibration curves or from reference tables of equivalent values bllscd on the cnlibllltion curves
Calibration curves for kok-saghyz alld heyea lI11tulltl rubbers and Buna S (GR-S Chem Gum IV Goodyear) and butyl (GR-I Standshyard Oil Co Protoc) sYJlthetic rubbers are hOWllil1 figure 15 The samples of kok-saghyz rubber were furnished by the Diyision of Rubshy
100
90 ~I) ()
z 0
1amp1 a
~ a
80
70
60
s 1amp1 ~ ~ 0 ~ KOj-SAGHYZ 0 l Il
50
HEVEA~ ~
40
100
90
~ 0 80z Q 70a Co)
a 60 ~ 0 0 x 50Il
40 ~----~~----~------~------~------~--~ o 2 3 4 5
RUBBER IN 25-ML VOLUME(MG)
FmUIlE 15-CaJiblation curves fOl kok-snghyz h(YCII Bunn S lind butyl rubb~ls (Readings on gy((yn photoelectric colorimeter with i20-lIIp filtpl and 6-ml aperture)
32 TECHNICAl BUIJLETIN [)20) 1 S DEP1 OF AGrnCUIlfURE
Iwt Plant JIl(I~t ignlioll of thi BlII(un and (1( l))(parcd according to 11( SPltI1((-Culd (]] (6) PIO(((lllll Hlpt pal( CLPPe was (xtmch(L with acetone blI()Ieit W 1I(gt(11l a ttnlldal(l
SEXSlllVllY Ol~ llETJIonS
By lip pIO((l(II11P olltlillP(l 011 ]Hlg( +n Iowa (lOOl IIIg (11 1111i(l0shygmm (gHlllllla) of 1hblI ill a 2)1111 yoltll1ll (all )(gt dltpltld Oil tltl Col(man (lohlP mOIlWhlOl1lHlOl l-I)((t 101 l1lOt 0111 ci( I ill1ilnlly 001 mg of Iublwr ill a 2J-1ll1 n]ulllP Illay bl Ilad Oil till EnI)1I photoshyllectlie (O]oLillllt(I Thll ya lllll- 011 tilt IHl-i- (J I (xl ad iOI1 fmlll 02 gill of til-lI tH(JI(lillg to tllP -lllndal(l jll()(pdull 1(PIPStlIt IlO()2J tlnd 002) P(IT(lIt of llIbl1ll IPI)(((inly bull1t1lollgh -lI1t low allils can be d((d(middot(1 il lIoullt1 Ill IPtllizpd thnt till PIIOl ill PlI(Plltng( or tll( al110unt dltlIllIilll(J i ltlatlpl high ill tili PIY lo Itlllgl 111 aetllllllladie(middot Ill( lopl lillliL 111)(1(1 lIw (ollllil ions of tlil ]lI()(lltlIIIl u ol1tlinpd ipt at l11 11I1 or 1111gt11(1 illt i-1ll1 Ollllll IlPIPltPlltillg 01 p(gtl(pnt of JllUiJtL un tlll 1Hli or (xlla ion rlOI11 II rlll of tisSIll
EIlIlOH COSIIlIHIIO
In Oldpl to H(IIp ill )1lHtPltt pl((iioll illlpIi1I- it i lH((SSHI to slnlldHIdiz(i rigidly 111( Pl()((dlll( 0 illdi(ntpd Oil pnglt- - to J( If lids i dOlH tlip lXIHlinwnlal PIIll is t(middotdllld 10 n ndninlllill
Illlt pl(iioll of (hI ]lIPPllt 1IHllwd Oil til basi of ]llllP llIllJt1 alld Ipsinssollltions call hI jlldgl(J 110111 figllll Hi lileh lio- til HPIlIgl d(intioll oft -illgIP lI1lnSIlIlIIIlnt in lHi((lltagl of Ill( alllOllllt 01 Illhshy1)() 01 lpsins d((PI1I1 iJlld TIl( (1101 PlI(Plltaglt H1( gi (1 101 OJ) to
RUBBER IN 25-ML VOLUMEMG) 004 01 02 03 04
i= I I IZCtOW
fbA ICtU CtCt WW a
01 02 03 04 05 06 07 08 09 100 = RUBBER (PERCENT)
RUBBER IN 25-ML VOLUME (MG) 10 20 30
~ I CtZ
bBOw Ctu CtCt Ww o I~
010 50 100 150 200 250 RUBBER (PERCENT)
RESINS IN 25-ML VOLUME(MG) 10__ __3-0_ 40 50 60 70 60 90 100--_-- 2_-0
Ct~ -r- 1 I OZ
WCt UCt b C wCtW
a o I I 150 250
RESINS (PERCENT) o 10 50 100 200
bllI 1tI W-Yllnl dtd1 ioll I I 11l1 11IlI11 1(111(11 1 III Plll- IlIIIlol1 01 IIim~
bull
bull
bull solution Il basis J o golH of tiSSII (JlILCl-nt (11(11) for (~I) (l)1 til O 1I1
of luhllpl lin 1 III I (I Ill of lUhlJPl nllll laquo I J to 111 nlg of IlSlllgt (Itllillgs on ]iYllyu pllolwh-llrk CO[IJlilll(-(PI with nOHIP Iiltlr lIntl U-lIll allcrture)
RAPID PHOTOlJElRIC DELEHlllNAllON Cn HUBBER AND H1~SINS 33
10 mg of rubber anel1 to 10 mg of resins in a gJ-m1 yolumC For
bull
bull
bull
comparative ptuposes the leslllts arc also calculated on the basis oJvershycentage rubber OL tltsills in 02 gllI of tissul As WOlllL be expcet(d the error increases sOIlHgthlf for 1(lali nmiddotly low COlHell t1llf iOlls oj rllbbeL or resins The curves in figure 1(j s1l0 that ill til(gt Illlge Ol to 10 pCrshyeent of lubber the elTOI rangts Jroll1 abollt Ll to II) ]IlC(lIt abo(~ this mlllc tIlt (ITOl d(((ts(s to (ollsidlItbly ltmiddotss (han 1 1lICPllt of tlH mllollnt ltl((Lmill(d Hil1lilally in tlH (lISl of l(sins analysis (fig 10) the ltLTor is (onsit1eIubly INS than 1 PlLllnt ill (he lallgp of 11 t~) ~() penPII t
In nil ([lSl of lllhblI alld (sins lx(Inltpd tIOIl1 (issups Ol addcltl to tisslle lxtlads (s(( tabhmiddots (i H) illyolillg ll01P o(lllntiolls the eLI01
is hig]wl thun that indilHtld in figllll ((j Im pUIl Ill )])p I tllllllsins solutlOII
COlllUCIIOXFOH IXSOLl-IlLl~ Ilgsqgt(Jg
111 th( Jllo(pdulP ollllillPd 011 paw I till illsolllhll isSII Ipidll( tflpl (xttlw(ioll is (Ptill tlw lIask l(lll till xtlct i l1wdp up to yoltlllH It is not rOllPllipnt (0 IPt()PI qWlIltitati(Ir III(lw[olH a 11(1 pllooll extlnlfs of guuyull I is-lll alll thl1l main t11l111 up (0 YOIUllllmiddot bpCaUHI sllch all additiollal stltp wottld]) tillll-C(JllS11ll1illg Th( Iogiea nll(gtIshynntin is to mnkp tltl lXtlUCt Llld Ipsidup lip to OllillH in till original flask andi llPSStllY 10 llwlno tl OIIpdioll wlHIl (allIlnting [hc llshy
Hults f(JI [hl oll111lC displupd hy till ins()lllbh llsidll( III it l)picat (IXpednHllt (ollsisting of Jhp lppJiea(iolls if was Iollnd llftt at ~iiO ( 02 gill 01 Iuhhll pillS IPill-fl(( lisslI(gt (lollpdll fot llwistUlC ou basis of dlyillp ut lOW 101 ) llOlll-j (lbp(ld only t~ llllUll voiul11P of OOk7D~- OO(lOO(i Ill of lllthyl bolnl(yl 1lIOll( (lplhlli(al-t(Tnltle sp gl () Ii I ll(Hli (j at ~)) -gtitllP tl1(gt 1It101111( () r t is-lIl xt Iadld j sl1lall til( PlIOI dul to Ill(gt insoll1blp Ip~idll is slllall III [0111 ill( wOtk it (all lJp diIpgal(ll(l
]hcon~lIY OF HllIllgl AiO HESIS AIH)gl) TO EXTlIACI OP
GlYlLE TISSlg
Tnl)ll G L(IHpslntillp (ypi(nl llld(~ SllOS (hat all a plngl of HIOK PlI((nt ot lltl pltl( Ilhl)(l acldpd to tllP Itll h iolJut1 InmiddottcJllP xhnet
of guayulp tiSI1( WllS 1l((PllIl Tlli nllintioll flOlll (olllplpU I((OYshy
PIY i within flll pxp(IiIlHuttllIIOI ~illli]llly fnbll Ii llows thn 1111 llYlIUgl of 1O(1~ ])(I(Pllt of gllllYllII 1(-i1l- add(d to II( (pllosol( (xshytrae of IUllY]l t i~HI Is 1l(oPIPI
THl~ (~ Hf (Off Ill of 1111)( J OJ I~il~ lItfI(( In ~(JI1IJk~ Ilf (111 [lI1Il fI2 lIII
0 tlUfllllit i~~I1
Instrument
---- ----~---- bull shy 1(1
Colemun ruono~ltrOUlllt()r 2t) II sJl~ctroJlhOL()lIIeter with 2tJ I iflllllI wnclength Fetting 21 II nntl 0-1111 WU HI hUJl(L _ L U
Ill 7Evolyn photo~lcclrie (olor JU [ imctcr with iO-llIl filler IV (I
H1 0 t I I
llImiddot lUn WII 1011 HIO Wn mil lUulon
10 JIg1111 IUI ml lUl anh Io aLn 111)_I ) III li lU It 2) deg wn2SU DD
Irl JIll II IIr II US II
1110(1 lULa lUI IlK) IJ WU
I( llI Htl tNI 1(111 2tlNI HI 0 221) lllil t2S 0 1~ 10 1~13
In (I 2117 I
10U 1l(J ~ 4 _H_j ___
9middotJIlJ5 10115 10 00 lUU5 flUU 4li (tl03 9(11)
leIlKl 1l~)5 lOOU l1KIr JOIS un 003 OIl Ii
34 lECHNlCAL BULLErIN 920 U S DEPT OF AGRICULlURE
COMPARISON OF PHOTOMETRIC A1D MODJIoIED SPENCE-CALDWfLL METHODS OF RUBBER ANALYSIS
Guayule samples were analyzed by the photQ111etIic method and by bull the modified Spenc(gt-Cnldwell mcthod The values in table 7 represhyselltativ(I of typical results indieate It -atisfactory dcglpe of conformshyjty between the two methods in thl range of tiSSlHH with llHHC than OJ) percent of rubbtImiddot On the bnsis of the amounts determimd the results in this runge for the plmiddotts(nt lIlcthod ayernge apploxinHltely j percent highcr
~LAIII~ 7-(oIllJl(i~on of lltlllrIic (IIri mOtllinl SJl(II(r-(ulri-wall IIIrtlwrl~ of rlrrlIIillillfl 11)1)(1 COIIrll of UI(III
1 Flowers frllm amiddotmonth-oltl nursery plants
YAIIIATJO- OF SIli(LE DETEnt1NATIONS Fnoll TnEIIllIEAN
Rllbbel (Uall8i8-Thc plcCision of thc pLcsent method when gunyule tissues Hr( nnnlyz((1 for rubber may be j udg(d flom I Ill datil presentcd in table H TIl(se dahl -how that thl pplCPlltag( uriation of single determinatiom from nwan yullles with low standllrd enolS ranges from less than 1 to 4 p(gtrlent
R(8in~ wWlsi-r-s lndi(a((1 011 page ~j he INntlts s((uled hy the present phoolllttric nsins llHt hod are not tliltly (olllpalable with those of the grtLVimetri( ncetol1l-cxtlt1(tioll II1etho(l Thjs made it necesSllry to selc(t another lalibllltion staudud-tlll Ipsinous exullate from gullyule shrub-thut gies relatively COllstlllt photometric readshyings (table 5) The resin (olltents of guayule roots branchcs or leavcs usually ran(~e from about) to 1-1middot pelcellt The ple(ision of the present methotf WhCll gUHyule thslllS lIe analyzed for reins may be judged from the datalHmiddotpscllted ill table 9 1h(se data show that the p(lcelltage variatiun of sillgle lhmiddott(Lminntions iLO11 meun ynlnes with low standard NTOrs rangcs from about 05 to 4 percent
bull
bull
bull
bull
bull
RAPID PHOTOMETHIC DElEruIINAlION OJ RUBBEH AND HESINS 35
IAIILE 8-luriation inclieute rubller (mallSM of [1wIIle tissue bll thc 1111O0Illclc metwII
Vnrlntlon~Ilbher I (rom mean
ierCtnl Percelll ~OU -22 ~ 25 +27 ~ 20 +18 ~UO -22---------1_______ 51110 0G6 bullbullbullbullbullbull _bullbull
10 ro ----=ii41075 -01 1000 +11 1010 +13
rlln HI itil 1l9~ 1_ ___ =-~~~
115511 ~ US -111 III II 1575 -13 115 b tiS -I a 111 h WlU +22IIM-(middot bull 11K -1Ja Illi c 1000 +03 1J5H1 W +l)7 ll1imiddot tl 1575 -13
Mcnn 15951 131
1102-11 21fJ() +21l102-h _ ~~)SO -17 1102-c bullbull 21CO +21n02middotd ~OIiO -26
2 r~plusmn Il~ 21151 261 I -~-------bull---__ _~~_~______l-___--_
1 lhe$ 1111($ I1n (or SlIlIIllltS Stpnnltplr PHrilClld IIrtlrdlng 10 1hr prollIlIlr( OIiIIiIl(o(I on Imgt$ 4 to IC ~tcond nUlI1 hlr r(J)[ltnts stl1ndnnl llrrot of tilt 1I1(1111
1_1l1~ n-J(lri(iot in relli(Upound rpoundsins (lllalIsfs of VIOJII( lixsue b1 the lhomillric lII(lloli
-- ---~--- - __-------- shybull I I I I Varlgttton
_________~___ ~~lu_n_Jl_Q_~~~_____ ______I__~_o~S_J frOID lDean
Percent Percentgt458-1 ~65 +41IWtl-li 130 -a2Hli8c aliO +26S41i8-d bull 130 -32
1(-011 34I10Olifgt __ bullbull __ ~--====
li-9~2n 881) -06 li-9~2-b Si5 o ~HH2middot(middot S i5 -6$-H2middotd 000 +1
8851 054
O i5 +6 9 i5 +6 950 -20 U75 +6
H-liG3o-n bull -1 n-li6~b bull __ _ -IH-IWH +4H-l61511 bull -1
1tmiddottlU
62~-lI __ 62~-b ij24-( bull OH-Ji
(-Ull
I rll(St oluls nre tor separately ~xlrflCled SllllllllCS IlctOrdlug lO procedure outllned ou pages 4 to 10 i Secoud number r~prtgeulS stulldMd error of lIe menn
36 TECHNICAL BULLETIN 920 t ~ DEPT OF A(]RICCLTCRE
ReUUER A~ALYSrS I~ CRCOE-RcuUER PROOCCTS
Sew rapid photometric m(lthod~fol the ddellllinttion of rubber and reii Hi ill uaYllp ti--ut htp lllell pIPHnl pd oil pag( ~l to In A brief H1111111tlY of It similar rnpid llHthod fm 1I1hb~rllnltlysis of u1lulcanizNl tlIldp lubbll pl(Hlmtlt whielt i~ bn-(tldo on the prill o
ciples dehtilcd tlllLe follows Duplltate nt-gm sllmph of the finely cliyiliNl IlInttlitiup wlirllll out [~ei-()l (all hl lIf((tinmiddotjv INd to lt1iyidl till alllpl) TIll kltolll-olubll portion of till )111(11( tlrc di-olved a- indh-Htpd fot thmiddot lllnkill~ of -tlllHlunlluhhll olutiou Oil Pt 1II hut tIl IUlIp Hn lIn l-fplImiddotd 10 lHI-ml rolllllltti( fln-k antil1ltld(lup to Olllll1l The bnlulUp or till JllO(ldllll i- thatutlilllll on paWs -1- 1 IHI Ii 111( 1(111 1- nIP IXPIP--pd nil til IHi or Iw oligiJla w(lullt of I Ill (I11l1p-I1l11Ilt1 1)(0(11(1
Hupitl PlllimiPJojgtiWllllllllh llIltllOd~ fOJ Ihl llPtlmiddotminntion of ImiddotUlJbll tlnd 1(-illo- ill -111111 Illllph of gutlYllll tiUl IIll dl-eli)ed 111() IlltlY d~o Ill nltlI1lld fOl III Iwl Illhlwl- and l~iJlmiddotb(lLiJlg plant TIllt l[Olllhup hns nlo b(l1l ntuptpl fot IIH lltlIll1illtltioll of lllhbpl ill 11lHhrublwl Pl(Jdlld~ HIIl 1111 hI ndaptld JoJ IIll ann lysis of ynt1J(gt( ic lllbbl[- The llllthmb HIP 1gtn(11 fill tIll fol1owill plimiph- III Grinding
tIll PIOPlly driPl t i~lIl 01 Ul tillg tIll pnHhHt to tll l((lllilllllh~lel of filWlH-- til plllllit qIHlIllilnth( lXIIHtioll 01 IIlbhlI 01 1(--IJl- () llsing oXWllutld olnuh (kttoJls IIt(talp and() fllltil for LIbbel and IH(ltIlIlyptIJllIllIoolYlnJld-o flJllh 101 niJlsl with t(lathelr high IlPililig points 111 to n C) l]olle or in mixt tIll thllt Pll mit tlll rnphllxututioll of luhll(l OJ [middot(ill ill ~() to (l mi1lutp It r(latiwly high 1lllIllllltlltP Ill to 1~11 ) l) lllllipitntillu till luhblI OL Imiddot(ill frolll aliquot () f till oltn ion I IlIlllI-i () f Hlltabhmiddot pl(~(i]litallt (willifhmiddotd lthmwl fOl IIlhlHI Hild llitlifild lllr fOJ JP-illl t~) IIlHkillphotollllliilPIIIIiIlof PlllPlltal of liht tLaIlS mittUl(P lIftlI IlIlbll (II Il in PIlipitalioll 11 II WI( Iplllh thnt (limiJlall till PIIOl dill 10 xtralllOlh (0101 (till dptl1minntinll Iph jill 011 tIll dtwlopllIlJIl of H HIli rOI1ll tlllbidity 111 hpl than I (olot rI
jJlIlpOP-ofallnlyi-I ( p(lllil1thb IIllijOI1ll turbidity or 1llt[lIinmiddotd d(ltl of jgtIp(ii(JlI l)~ lIltlkillU tIl plllltollllmiddottri( ntdillU al tandinu tiJlH~ (dlllilll wlli(h IhlllH(lill-- IP 1llutinmiddotly tnhll) t1ll1t an hlsl~1 oil the (oJlItlIlllItion of IIlhlHI Ill I(ill (lIPIipitat((L
TIll -I(p ill till jll()(Plhul HIP 1-- follOylt (1) 1l~UIIL uJ1lplls of thwl UJfJlllHl (II tliddl(l HUt dlipd 11Illtplial an lXIllltel with11 Ill of till nlnll ill t (oU tlllltIPlll[gtPImiddotatlup oil Iath at 11 Cbull fol 11 minutl I) iIP1lIin(middot(lohd til( (XUtllhllll Jltldl lip to It middotml ynlmlll til( (nlifild by (Illlifllgiuu HlId thlPl IlI nliql1ot of tIl (IalioPlllxUlltl nll Uillltlmiddotll(t to l-llll OIlIIlIllril fiuk- (1) For a trial Ilnditlg 0111 III tlll j liJmiddot~t IllHII IIjI to Ohlllll with lilt Pll shy(ilitnnl a 1(11 it 111 (Dod fill llli lIut ( ptotoJIIltlil IPtlllillg-- of pllllntnl or liuht tlUtllIlillal(I oil n (lpel OphotnJlllllI at rase hng-tlt (If 11 llJ Ill Ol It lollllil1lPtImiddott lloyidld with tIll P10]11 I 1110110shy
Ihlolllltt hmiddot Ii1llI Olllhi lIatioll for -1IpItillg UJlproXilll1l tply Wtl P ]Plwth )0 mp are HHlltk TIll Illldillg lliJtaillld fol tIlt 4-milutl tliall(~ll-
bull
bull
bull
RAPID PHOTO~IETRIC DETERIINATIOX OF R(BBER AXD RESINS 37
ing are referred to a table of equhmiddottllut~ previously p1(pa1elt1 on the
bull basis of 4-minute reac1inJ~ for tilE nmge of lot1telltlatiol1- of rubber or resins to bE elHOlll1t(led tmd gidn thtmiddot -tnnlillfr tillIP fill rUbbEt or resins aiter prE(ipitlltiol1 lwfolE photoIllNliI j(tltlill1 un IUade The r(middotnmining dllplllatt aliquot lll then HHllil up te ol1l1Jle and lpoundadillg ale marle ut the -tandillfr tiUlE iudklltll ill rhl tall1lmiddot for the final r(adillg~ -1) 111( milli1lnm or p(tCPlltllt- of lllhbpL (II 1(-in pr(s(nt are rpadholU a prlpan(l table of lquiltlput for tlll photoshymetric readings h1~l(l ill pnell e1-E on pxpPlilmlItal lhln 1111(1 u-ing as stimtlltlds pure luhbll in 1l1bbtl milllYb aIHI guaYllh ll-ill- lxIHlatt~ in resins detNIl1111lttion I
LlTERATlRE CLTED
(1) lUnSbull 1fl36 THE mURMIXTIOS IIF IOTA RE I III OOl THER llT~II
F1 bullrol IlY U(T1l0fll UfSlfi ~rrnrl r flm lt1 KEYS TI Bill Chern 114 44J-l59 illns
t1 ~ICPHHlObullbull T 1J3bull~ lUTHOO roa THE PtRInCAnu Or a(lIUl IRrIlHU It of TIn
PLRIHEU Htllllflt [ i Bill lallllall 111 Rmiddot 711middotj iIlus
I ) RHBERG P B Ul5 A METHIlO Or ~u(ronrll-nl Hi tIII rUIl[1 f71 ii illlI
bull 14 Hoss W flbull and HARDESTY J O
llH IR1ltDII Of HfITilIZfmiddotR DllIJS ltt 1 Yl fll Off gI bern JIIIlI i ~middotmiddotlf IIl
101 SPEltCE D nnd CuoWELr ~I L 1933 DETER~n-ATIOo OF RtBBER Ii nrllllpoundRBfR Iusr 1uI II1 amI
Em~ifl cttIliIa~~ r Ell i 71middot7i l11 (HI WALTER E D
1U44 ISO~nlS OF PRTlltSrr 1trHpoundV bull l UI n W lHHt (Tnmiddot 1ETS FROM GiYI l~iIl lItr Clttrn SII J UI titJ middotn9--C1 ilIu
17 J YOEbullbullr H lO~( roLORIlETRT 771 IPmiddot nl -W Yurk f H Plrwptric hmica
naly-II rimttry lUll XphHHlnmiddot~ y 1 1
11
HI) ~ fPHELolzTRf 57 111bull Lin xw Yk t H lt PhmeHt CblUlmiddot ila AnaiY~l~-(H lithrry and XIhmiddotILpfIY Y wirh enomiddot rrJlllrjr hy H KtlJnJU11 I
t~1I --- and ~ARVER L 1f41 nlua-w ~in L liLhr IS IP ll~ XIW Yrk
bull For-sale by th~ ~a~fr1nt~nf1ent Dt~c~~ogtnts-~ s t1i rArnn~ut Pn~~~ tJffieshy
Washington 5 D C bull Pl lU ~nts
RAPID PROTOMETRIC DETER~UXATIOX OF RrBBER AXD RESIX-i 19
GHl~DIgtiG
bull Th~ entire pant 01 plant l)iHt a~(gt fl r(ll it pllllIIirU1ry lSillg fur J hours ntGi~ C prIOr tD t 1( plChmll1atmiddot rLlmhll III a II lItmiddot or n Ball amp Jewell mill ~n llltllysis of paldch lzP- nftl~l (oar-( IIindill shows that tlwy ar( about tIlt llllH fOl parbojlP(t awl IJllllluhoileu hrubs I fir 7)
The coalilly gloUllll ample i-- thPll Ildlll forI toUtmiddot at ni C afnr which it ha lllilobtllL(gt output of ~ llllut lII hmiddot- dptPlIIlilwltl by drying submlllpil- at 1110 fot hOtll- TIll 1 IIIIll i lltllt lmiddot0l111d hi a IluninHl mill TIll mo(lel uP(t in thi IIIk i 1I Hu IIIOilll mill as IllUllifill bv Hoss nnt Hartlet ( 1 -[1lt111- with n1ll1l1 pldushyrations ittI lilnbhell b rill HanlIolll V0ll11nHiol1 ElIillllmiddotrill (0 The size lutllihl11 iUlJnole So I ( 111m t ~ II t HUIII Xl) ~ I L~ 111m nnd So 4 lillllU1 11 ttllilhmiddotj 0 r tllP Imiddotlult~ p(lln-It willI t11(e Sll((IIiZtS with )arl)Oiltll awl uil)Jtllboiltd hrlll b lOwl1 in fif1l1fmiddot-- This hows t tnt 1middottttIl ~(I 1 llllll (Up jlllilnl IHlt that
r------~-------r--- ~ --r IHAMMER-MILL SCREEN
O~ NO1
NO2 ---shy U NO 3 ---II
I
bull lL
z
r ------ l 30 ~ gt III
i I Imiddot
i ~ I
I 1 I I
~ 20 I - 1 iii 1[ r 10 ~ ~ ~ I _ ~ I r A bullbull
o bull L-~__~__~~__- ~~ 20 40 60 80 100 40 60 80 100 200
NATIONAL BUREAU OF STANDARDS SIEVES (MESH 1
Yutln I i-tlillltiuli Hf pur id lZt f ~naY1l1 t middotnt r1 lI1 i ~ a hatlltlllI 1IIi11 to 1111 Lx IHtllllH middotIn Lt-anmiddot tIlllunl loy la1 litkh~ omrl t 1) tHul parbuih~ -t B ~ thmiddotfuliufptl ]~lahr thpt tu tt fit t 1 It+gtr-tt1 Jnui~tHn eunttlIt _~rnlitl tl~UP ltakmiddot~~ 10 UddU it~ 1 rtmiddot4~pt~middotK1~r ttakt-middot
bull So 1 gingt- 11 tt-liuin-Iy ltr~pl [lPlItl1tat of iilll 11animiddotImiddot- Eqltrimiddot tIlllll hnnmiddot llOWIl dutr fll llltldllllUU xtlutioH 11pound lnhbll lIl lP-ill frolll IolUlIl ~tlaYlllt tl-IlP by dlt IJwtmiddotlUlmiddot lItlilwd oil Ill 14 - 01
i-mllt 11111- -lwltld hi INd I li~ Ii I TIll lllhtIlttj of Itiu~ So 1 (lltll j thnt 11middotmiddot01middot lttwmiddot to amplil tltt Iollllli tilt art lpdnn ib
IntIIll ll~ i po--ihJI with tI lLllit Ilfltl[lll1t It honld l Plllplw izmiddotl rImt ilt tht h of -allllhmiddot with l lllblPl
~ontlnt of ill PPltllt til lIilll it i tlllt pll--ihl 10 11-middot t(1i Xli L
20 TECHNICAL BULLETIN 920 U S DEPT OF AGRICULlURE
Even with screcn No 2 difficult due to rnbbel tlcrltreCtlltiollS may be ob tl
encountered In thes~ caHeH it iH lWit to parboil the shlub fOL leaf lemonll and finally to dry to about 1 to ~ P(l((llt of tnoiibl1(l pound01 b(~t results jn ~rindillp in tlH hanmHl mill
It iH aclvlsable to provic1l thc hammer mill with a ground wire Hillel the presence of static electric (harges 011 tll(middot partkhH will ealls( Home of these to atlhelc to the inside of tllP (olltailWr OJ lila eallsc OI1l( of till pULticl( to form ngg1(llatls EIIolin lalllpling fl01l1 fhis SOI1I(I mlly be (onsi(h1llbl(middot
A1I10l1g the Holnllts with high boiling point that lIlay Ill IlHld in rubber anal)Hs I1IP Illllhyl n-alllyl ketolle methyl ioblltvl kptOIH diisobutyl (tOIH blltyl tHptate llethyl amyl 1Ittail (middotthyl(middotlllmiddot gly(ol diethvl (middotther and n-bntyl (middotthel (labl( 1) TIHse al( also I(sin 01shy
middotent but th( 1(~illS n1( held ill olution by the rll1)bpl pl(l(ipitant tthanol wll(1 lllbb(r is 1)J(lipitatNI (S(ll tabl(s alldmiddotl) On tIle basishyof the lxpHilllPlltH tll( btsf nil-round lolPlli -rol lS in 111( PIlHPllt method is lt1iisobutyl kPtonc wld(h was not IIltlllllfaltllllmiddotd ltIlling Vodd Yflr n A suitable Sl1lgtstit ute iH llHthyl jolllltyL htolt whi(h is l(porhd as llolltoxit UJ)
Clllos()IY(~ (ethykn( glYlol monopthyl (tIH1) blltyl earlgtitol (di(thyl(ll( gly(ol llIollobutyl (ti1(r)~ and acttonylacetOll( may be used as resins sohrCllts (table ] )
In the earlipr work with (sills analysis cpllosoly( alolle was selcmiddotet(d as a suitable solycnt Aitholllh (ell()~oh( alone is pxc(lllnt its rplllshytiwly gwatlL iscosity 1(I(b to bubbl( formation nft(I (SillS pr((ipi tatioll Thi- increased thp (xperimentnl (LTOI OIl of tltp othll I(sins solpnts tI((tollyla((tolH has the proppry of glpatly lNlulingshydH(OSity 11(11 altld(( 10 othr liquids This sohpnt tlHIeforl wa addp( to ((Uosoh( in slIflici(lJlt tlllIonnl to OPI(0111e the dinieulty On the basis (li~ex)le1inwllts ~ purts oi~ a(donyla((tOlll to I puts of (elloshysoh-f (bolll by olume) as Splldcmiddot(l Thp 01 hel Hoh(nl listed hutyl clLlbitol at l(llst the t((hnieal-g1lld( ploduct uSNl is appal(ntly not as good as eithe of t1w ot1(r two () a (ombinatioll of tlWSt
The SOlVllIts JOI liSt in tumlyzing artifkial lubbel$ hy tlw pr(senf method appllLently (lcllIHl on th(middot kind of llI))(I lIp-ityl (Jxidt is suitable Ol BUlla fi and hutyllthlI for butyllllbbl Tlwse reagents IlLe technical g1lld( Calboll amp CtllUil1t Ch(lllilai (OIP This Hllbjp(( hilS not bepn (XtpllHl(ly illwtigated by till WIit(I
PIIECIIIIJ-
All tlst fOl Ih( adlqlJalY or till IHllipitullb ll(Ollllllentillllll11Sl bl baset] on the plctisioll of tllP final I(snlts oiJtairwd with the methods The )redpittlllts s(1e((( n HpJ (xtcllsi( (xp(IimPlltatioll all HatiH~ factor (Hee fig Hi 111lt1 tabItmiddot (jH) Ext(IIin tllts llllTild Ollt hanmiddot shown that H Hatil-gtflltlOIy [gtIpeipitallt 101 1lIbblI is (li-p(IT(middotnt HzHO (c p reagent nil POll sp gl U-lmiddotJ) ill li-P(l(Put (tinmol by vohmlP liol (tllayul( Ipl-gtinl 1l)-P~ITImiddotllt H)~o ill Hl) by ollln( ii lL satishyfaeto7-y l)lp(ipitunt A solution of 1 palt of H~~o to 1 part of H~() (1-1) iI2So1 nnd abo yarious int(lIlIPdiat( proportions of tlllse suhshystanCPs giyp fait 1(511It8 but with till inlIptl(l ill [h(gt ratio of H~S01
~
bull
bull
bull
bull
bull
RAPID PHOTQlIEfRIC DETEMIlXATIOX OF HtBJER AXD RESIXS 21
to H 20 the )olutioll becollles somewhat vbcou5 and precautioll Il1Ult be taken to ttvoid bubble formation When it i5 poured into tilt Cllvettes
It should be lloted that both of these precipitants have an ftellleshymmiddottion It was found that when XHjOH was used in the rubber preshycipitant in pInt of H~~O~ the readings were -table l)Ut were not reshyproJutihk The lIl of XuOH in pInel of H 2SO j ran nHittble result as a llth H(HY(Pl WIWll til( li-P(l put lthatgtl in lublltl llnalysis or H~O illlP-ius anal)j wn-i uddint(1 thl eharalteliti(s of till liquid with pleeipitated ruhber or resiu in HI~P(ll-ioll n ren1 on the lpNmiddottroshyphotometel m tololinlPtprfollop(1 it lPgnlal lIlll II~ lxplaiHd on pHgP-I (Sl( figs 11 aIlIIl) Tid made it lloible to outain lEPJOshydlHibll tpnlt nntI (onplt1J1(Jttly till JpqnitPIl tlPgJPP of PJPcljoll
IIWIE(TI 1lt COl~101J)
Jtl thp ItJiPl middotxlwlillltnb hefoJ thtmiddot -1l]YIlIt allll pnmiddotdpitallb had lIptll ptoppJly adjutp(l it l fOllll tIuH till llP or a Ploltiw colloid -wll ltIi1)cJ [ttlJmiddotntl- imlIopl tll lmiddotpro]lIibility of the lPlllt JmUkllly ()Ilt 111 U lput lUlU illlihumiddot tOJllPOlUtl tpHd liglyeol teltlut( - llpanlItly IllmiddotlfP(] to lit til I1m t IHflll lImnnmiddott nftlr tlH filial prOIptlllll WtlP dlvPllill1 tlll 11lIlpfit (If thtmiddot [llltlltin lollohl wa Hot 0 natlv I1l(lhmiddotd III rlumiddot Ia- of tmiddot ill tllmiddottJmillaritlu it b [1 hmiddotjlmiddot til IIpoundgt Ir llH1 It liltr ill-llImiddottiT Ina lll ptlPII by it U( in ruhhfl mmly j 11If dtmiddottail fOJ tltt lllllmtlllll If thl plot pet in nlloid ~llntill tltlmiddotlImiddotmiddotlttlatiflll lIOlllllllhtiPI1 are iPllllll page
liTFHFEHliG COIOf
(hi II tht lllail 11111111111 that had til ill -111111 II urklll) om tlH method fot lublJtt tlIlO1 rpir- nlalv~i in plaut llllpll- wa ttl (lilll~ inare tIte (gt1[01 till to tIll ptP-PlHt f xi [aIWIIII- 111 TIlt amount of (olor varip from lUllIt tn -amp ]pplwHlI nlt rhmiddot lt IIf thE Hl(ltllial tllP part of till plllIt -lI11lhmiddot(l tilt hi-tlllY f tlll plaut mtteshyrial ~ub-lltInent to Itlllmiddotnmiddot-rill lliI 1011middotly OrllPI Inlw
In ruhlwr lrtl-i I Iii 1101 au Itmiddot 1Iplll11l by 111[ I--r ratmiddottilt thE -lllll]t with uptoIw or 1middotmiddotlIll-ol - wIdell [llllol- rlll loillriu nutttel autI thtmiddot lpill- Thi- howmiddotvt n(tnll- til lXtla -11gt1 ilt prlJ~edun) In lP-ill ltluay-i nllHufldy tlW[t j 11 1 1IO(PIlln fill the 11shylImya of hlulophyll Hwl rIlI-r middotIOII IHlttlmiddotJ dlH lUtl~ In plltIH withoUt alo aiftIriL till nmiddot ulttrll
111 pllIbIll1l Wi tilmiddotr hId h It-ImiddottHI tht Pltlpll 1 hlitlt lilt tlw tulllWlli tollImiddot uIwltllIIntut -lltUIhorlllllltll 1111 tIll tlettlllliIttwr IIf t 111 lWlrl-Uamiddot of bdt tl11blLlittUhmiddot r [1 tItmiddot preshyj
lipitatifll 1lJ llllllWI atbull 1iI- in III -1nrmiddottIi fHlttalldh nlrillU~ amount rf middotlorilig lIUlttll Iii lhll of ih lltmiddottllllhottohttt~l l~ol()r infrtl Hm II upd 1 rwmiddot tld~middottilmiddottll PlllItlhi~ f it j proYitiltl with tIll lilP--UlY tU(jlIdlllIlml tIltmiddotmiddot lllklllUIlI
EIECTIol OF 1 [EGTH~
-Ptfmiddott ral tracilull ru~lI gtIll fr 1 nllb t ~xtltd 1 lIlt-th vI iobmy1 ketommiddot lWtl rill [ Ixt lttltt ll UttollylaIiIitt1l11I1t~ ~-I itoiu YtHil)u~ typp of ~IHaylllt f i lItmiddot art hraquoil ill fio1ll1 ~l Th~ lp-nlt fill I11oohl uio[1t ttl willlr til tltN- fur rht IUiXtIUt iwliutll
100
22 TECHNICAL BULLErIN 920 U S DEP1
90 bull eo
I shyz 70LLI 0 a LLI a 60
LLI 0 50 z
a ENTIRE 2-MONTH-OLD PLANTS~ 40 b ROOTS AND BRANCHES OF ~ 3-TO 4-YEAR-OLD PLANTSen z WITH LEAVES REMOVED ex 30 a C CURRENT-SEASON GROWTH OF l- )-TO 4-YEAR-OLD PLANTS
20 WITH LEAVES REMOVED
d LEAVES FROM 3-TO 4-VEAR-OLD PLANTS
10 A
0
a Cd 100
b bull
10
80
I-Z 70LLI 0 a LLI 60a
LLI 0 50 z ex I shy 40 ~ en z ltI 30 a I shy
20
10 B
o~__~__~__~~--~--~--~--~----~--~--~ bull350 400 450 500 550 600 650 700 750 BOO 850
WAVE LENGTH lM~)
FJGcm O-Sll((middotlllll tramaniW1IHl (mrpS f(JI (xlmll 11011 n J1ll of jlta)nle tissur ill n 2--m1 Y011111P of (A) Illrthyl ji1I1J1ltsl krtonp 1111(1 (ll) nt(middottQnyla(umiddot tClIc-C(l1osuln a-i
bull
bull
bull
RAPID PHOTOlIElRIC DETEH-UXATroX OF ntBHEIl AXD HEstxs 23
ThE dula Pl(S(l1t(lltl indi(ntp Ihut 101 Illp ulimls llHthyl liohutyl htOlIl (lxtrHts (lI(I r(dolls of Il1Hxi11111III nigtol]gttioll wiH1I all (is-lIb 11 cOllsic1(]((l n1( blhn(11 wn ( ItIl( Its lIO to () I1It~ nlid Ii to Iii mJL
WhllNIS tlw I(gions of 1middottnL(s( light 1lnlllittamp al(l lgtPlW(PIl wan Ipllgtltsnr) to Ii nllt jW) 1I1JL nlld alio Silllill1l 111l1b (n SI(lIlId 101 nc(ton ]altmiddot(fmiddotollp-(llloolp ~ pxt Ill of 11a 1111 t illl TIl( (1101 du( to lolo ill tlw litlltitl a 1Il1 lullll(I tH lPill- hanmiddot bpllI PI(_ ipitated ma he 1((I1((d to fltI ynbhing poillt II ph( illg OJ illshylmiddotJall(( WIWp balld nhm ()) IIIJ1bullbull[1I111 lxjlPIitllll1b Illln -h()1 that Ih( lIIot uilahl( WHYI lHlIJ fOI 1-1 ill 1l11J1l(I HIH11Pill- illllllrsi i-in till IlPighl)()lllll()(l of ~llIl1lt bull
bull UIlIilHlIy of n typhn] lXPllillllllt to )10 l1iP(tiP ((JIlllo( of (ItOIS dul to lOIOl in 1llblnI Hnd Iill xtnumiddott 11(11 IIIIolp t jUl i p1llelll((l ill tub]lL Till llhlllt- 1tpIO]II Hnd ((llll~()h whit-h UI(I ](]Hllilltl n 1I01lllIhb1 01(111 lxt 11111 IIll 1llll)1 nmtp[in I and )(middotills Tid IIlnkl it poiblp nftlI tlIp uplll1tillll or tlll o1PIl( (0 [niH lip 1Iidl1p~ of lI111 11111(( ill lit ll11l1)[1 (llnlIb nlld Ihll
Sl(ll n ol1lliOI with tllP olnl IJllt illiollt HIl Iltlllll llllI (Ill ltllthpl prpipitnnt j Ihll1 nddld OUI ha a lIilPt lP( of till lIiciPlw of WH( lllIgth 7) lUI- ill llilllillatiu (nnl till tll Ixtll1I101l ()lll~
Tuu tmiddot-Elilll IJl flrldillY 11-1111 lrlllI IjfJI til islII 1 1(1 ([rllt IIIIIJIlIr JiIlIt~ if 1Il( Ihll 111111 k til I III Ilrln I 1Intd tf 11111 JiSf fill I I II I tIII Ilf Iilltl 1f1JlIIillII1f I Till 1[ 1 IId 1 (I (middotIt 11111 (I1I1iI1 1lf1IWtlfJlIIllfflr p middottrllhIJ11 II J III 7IImiddotIa 111 111 lilt jJIp 111 wilTII
t~t tnVIli~ ~nn r kn t~ i tmiddot ~~l Jr 1middotmt ltlTt
HmiddotOtt ~I~ lin t I ~ 1 t~~l ~qrmiddotthtmiddotrtwb
Hult-middottltlru t T Hw ullut rHtt~ r II I ~ PH~lllt
A~tmiddottHHjmiddott~rjd rl ~gtllh 1 tn~th~ ~ ~ middotI lt~ b w bull hmiddotth~ 1i~lIhun 1 Ii tnl Illd1 -11lt1(11i lullI lUI tJl ll~ t1~11n( I Ihan1li flfttIJir Ult I Uuhtltt ahuul l(hmiddottHmiddot~t trv r fti HIt lftbyl tlonhUt)1 k_hIl( 2 m~ fmiddotf tuhlHmiddotr In mlth~ llmiddotlf- 1 t r
t r_~ t j
Arhlitlltd ~llIIDHl NcWitn1 ( Ar-(lt()nc~middotttrrtrt ritJJI~ -Iu nllJtl4-middotr
ACtmiddottflnp fmiddotxtrn( ~ T-P511ftf tn mtmiddotth~ 1 ~difmiddotut~ kdn 2 nltt ulruhhtr in Un-tIl lltbu )J~IYt
rUth(Hl~hltlft HhubU
Illlh(I(t tttUtUt hUbtl til J ~jlitl(J Hilllll trtIIImiddotjtl1ll
(UShl I ~tlO wHllolH rulh r (middot1111$0]( J~rru t t )lthyl 15bullbull1middot1101 klll1l
Ili( UHUicbcul ~((i1rUtl ~ulu1iin 1middot lIUIll Ilti lrllltlllt I Ruhhr llt1thuI r1 -1 Irld
ltlt1111Sh 2 nuz f)rruhl~rm nlith~l tu- h f nt nil~middothgt(H] tlrlftmiddot 9lUtirtl middot1 1
rlcltfl( H(l dnllltml it
(IISllhH~rI( Iultruhtr CII05 1v ltTlft I 2 UI~r ublwr In llldh I hlt~1 11) lgtjdvr(llsl~9rlltmiddot middotlmin ~ I~ gt AIHItilltl no IrttipHallr iI
~ Bbnk 10ol m(thyl i~tmiddotut~i kdHn H 1 m1 j~~ l1rH-t lt~tlfltmiddotn sf n it ll HltlMjftr~nol O2~mlJ ~U~1o-ulp ti~tW -xtra~middotl(lt1 ltt 411 ml bull ie f Ct- kft rt t~ tirattJ middott ill r u l1kn ttJt
in metltl isobutyl kNqnf nn~i mljp ur tmiddotmiddot ~oml ~urr tttl i t w ltJj1JH kt 4t 3 nlank 1 mL((l1t~rthmiddot(middot mI mttr~ ~but a kmiddot tmiddotc d 11 ~ gtli~b~ hifIAft- fl~ lL lnti 149
ml8(dlfilll BO bull 02 gm guayule U$Stl(middot xUlClt-l tf(h tft wI n nmiddotmiddotmiddotlgt 1 lznt on tmiddot ~Jt r~1 ~~u~~ H~ iI~ thT
24 l$CHNlQAL BULLETlN l20l S DJltJPT OF AGHl(CLlOHJltJ
In table a is pl(sentc(l such c1il((t edlt1tIHC showing that thc (0101 Ixtrnetccl from guaYIIle tisslIe wit h II(P(OIl( n nd (pl1oso[yc is cll(div(ly sCIe(nec1 out by the s(lp(tion or wnw length )0 miL Oil t1w SI)((IOshyphotonwtpl This tnb]p all-HI ihos thai thl Juhlwl altl(l((1 (nn IJl quall shytitntivcly 1(I(()(Ipltl in tIlt PI(ilIH( or Ih (o]OIplnwPIials and Illsins and tlmt Iuhb(l WtlS nppnlllltly 1I0t (xtltI(((1 110111 11l glll1I1l lisslIt b~ tlHSP SOhlllts Thls( ((suIts ginmiddot (OliIHillg (idJt(( that t Iw IISI of waYl llngth i)ll 1Il) OIl till SppdTophot OIllltPI ii t hl 1101(1 p(oshy(ellule in photolllliTie IlIlalysis of luhhlI OJ l(sin-
SELEGTIO- OF )IOiOCUHO)IAIIC ItIIm ((1111110
On th( basis of th( IPHIlb shoWIl in tabl(l 1 al hlllpls (1( IIln(lp to SPCtl lC the PIO]Wl 11101lO(lIOl1ln til Ii ltlJ ((lIllIJi nIl ions 10 llIiOlS (oIOlimet(Is 111(gt 7W-Ill~ filtpl flllnhwd 101 til( I1~lI1l photoshyplpct1i( (o]oriJl1ltll fol which Ill( (hlll(IlIiitit~ oj t hl Ilda he light ilUIlBlIIhiSioll (t) elll nn -hO11 ill fig1lle 10 iws satlsfa(lolY IPshysultl 111( iiO-mL HitlI olllhintioll 101 whkh ttp (middotIatinmiddot light tlnnsmission (ullmiddotis a 1-0 showlI ill figllll (I is -nthdnlto1 hut this is not stnlHlnld NtllipmPlli
Up to fhl PlPHllt lIS(middotflll pound11((1 (ulllbinntions jn lltl iOO-I11L Iunge hayc nol bllll SlClIlld 101 lhp Klpt 1-1I1l1I11PISOIl (olOlinwtll bu fnltlwl nttCl1lpti 1( )(illg IlIHd
TJIpound OF ST~lmW AFTEH HIIJ1EII Oil HHSIS rlll~CIIITTI(J
~ considl1ltiol1 of ttp lillll of Inlllling af((1 plpeipital ion of 111gt)(1
01 l(sinSTlOIll ollltionis impoltant J(jl~ thC1HI(Plltngp of light IInIlSshy
11 rshy10 f shy
09 f shy ~750 Mil- DOMINANTI
~ 08 cshy I WAVE LENGTH z
I III III i O7 - I III
~06 - 05 shyw
a
Igti= 04 - 720 Mp DOMINANT ct WAVE LENGTH- ~ 03shy
02 f shy
01 t shy 1)O~~~gt~- J 600 700 800 900
WAVE LENGTH (Mp
bull
bull
bullFIGlRt IO- COJllPIUlItiw ~IW(middottltll tlnIlRlllii-lion (II (IllP( 101 1i11(1 olllhinulloll
with dominllnl Il(lllllgths at 720 and 7iO lUi
bull
bull
bull
HAPlD PHQTQlfE1IUC JjETER~lINATION OF Rnmrm AND HEtiINi 25
mitted (spertrophotoll1eleL lCuding-) Ol light (1 (tClcrl (phOlOshyJluol01l1et(L lcndillg~) i~ StlhjNl to (hangl
]fjt~l1le 11 and l~ show that ill til( (asc ot tJaugtIllitteltllight llJHC th~ (x[llliHlllIlnl (oIHlitiOllS tllpl j lilst n dtlln-e ill Pll~(lltngl or UllllslllittnlH( follrnY(l by It ptJiml of lClntin stability with only sliuht (1111 tHn- a f(Pl a lIt1ll1btJ of minutes The light t UIllllitblllll t l(1 ill(Iln~(s This lIIay IJP llllllJltlli7P(ll1 ffl II ow 1Ilt )( f(( darI oliIII tIIlIlNlIlitt(IIIlfJIIlh (iditilIiid Ilil1 pllIipintnl )uoshyIn Of ( 8inx in (~f1( I~iUII i~ Ild stahl I 11 itlll If 1inl nh prlshyilli(ioll of 11l1d(1 II IJIX f) jllIli II (fJJltfiIIlilty slllMI IIriot 1) IIIPldUnl1i tll(I1I rllltltilJl oj tJi~ Jlt jiot IUN ilUf Jxl1 will tIt( tOWI IItlllilil I 1llIlllblJIol I ill I~11l11111 d ill till ifjuids JjOI scnttplltl light 011 till phololltHJIOIl1lttl till dilPCt ion 01 elangl b tlw IPrfIi (If that illrli(atPll rOl tlulll1Jittp(lliuht It Itlll b( llluliJr I-(Pll that if l(middotndlnJ- IIIP mad n itl I t lIP ~()ll1d()lb lpalll this pllioJ of nmiddotlatirp tuigtility tllP llLot tIOllt thi Olll(P (nil bl IPdUCld to tIl lltini III 11 Ill TIll l~adiltg (illH~ bbll Oil tlHl datn rUl lublwls and llsinlt Illl ginll ill tnhh
50 r----------------------------------------------- f shyZ
~ 40 ~----~W~A~V~E~LE~N~G~T~H~7~5~0~M~P~~~~ ~ --------------------=-=-= ~ 30 f- WAVE LENGTH 540 M~ _z _____ ___ -=- __ _ ~ ------shyt ~_=---=-=--I GUAYULEIII 20 -Z HEVEA ltt II KOK-SAGHYZ f shy
4 6 8 10 12 14 (6 18 20 22 24 26 28 30 STANDING TIME (MINUTES)
FIlirtn 11 Emmiddot of wav hll~rh Il li~ltr tlall~lIIit1alHl aftI IUIlItHt -Imlli lug 111m for guaynh llmiddotn 011111 middotiolIlJh~z 1111111 llijlitul1 flolll 1lHlh~ll1Jllryl k11II11l ~(lilltlll h~ lwitlitll 111Inu1 111l~1It1 2)1111 o1U11111 (Helillins on (illllun tlunhll IlIIJlllw]ntllW111 lutl(I[lholtllllltlt with ijUjt Wlnl IHI Ilf1 I
11 EFFEGT OF Hbli 1 -()JXT10~
Tilt lnblwl ~()h(llh pxtnl( till IPillgt ubo It 1m nllu1- bellt -~atea thut ~lll 11-111- tUP olnbhmiddot ill middottIIlIlOl ~1It tlWIIJI( my U)t PIl (tlIHatcl WIth tl1l lullh(t I tahle lJ 1hln 1- -1111 tIll (llllstlOll of nny p()~iblt tITptt of XtIIl11 diflp]lws ill ((JlllPllttUliollS of 1l-in lil lolutioll alollJ with till 1lIltbpl TIU data ill wbh +ho on tIl( hn~is of (olorilllPill ladillU thaI tll( IIUOIl1t of lnbbll Plllipirntld 110111 Ilwthyl olnlld kptOlll olntioll IJ 1li-jHlllnt 1l)04 in 1-llltlIllt ethallol)- not amlll hy thl llllNlI(l of llvin aU1ouut of llins inolution bull
-----
26 rECHNICAL BULLEfiN 920 U S DEPl OF AGRICULlUHE
100
90
80(I) C)
z Ci 70 UI a 0 60 a ~ UI ~ 500 ~ 0 I Il 40
30
A 20
0
100
90
(I) 80 C)
z Ci 70 UI a 0
60a ~ UI E 0 50 ~ 0 I Il
4-0
30
B 20
0
--
--shy ---shy---
2 4 6 6 10 12 14 16
---shy= ~ ~ shy
-
2
025 05
10
15
20
25 -30
35 40
SO
-60
=70 80
16 20 2224 26 26 30
OS
- 10
IS
20
2S
30
35 40
-50
-60 -70 -80
bull MGPE 25-ML
VOLUME
bull
MGPER 25-ML VOLUME
Florm 12-EtTld (If till1l or Slllldill~ 011 light transmittallce (01 (A) gUllyulc lnUIl(I plccipitllitd frOIll llltt h~l isobutyl Ielollt solution Ily neidilic(l ethanul bull null (B) gUllyule ll~illii pre(ipitated flom aeltoll~lllcetOlll-Cl])osolY( 3-7 solushy11011 by H(illilip(i l1U (HPlldillg~ nt -lIlillult Ifllpluls 011 Evelyn photoelectric colorimellr with jU-lllp tlllll alit U-1I11 npN(lle spp also table 2)
bull
bull
RAPID PI-IOlOMEllUC DElEnMINAlION OF RUBBER AND RESINS 27
TADIbullbull ] 4-ReZation of amiddotmount of middottbber pleeipitate(Z Oln metltlIL isobutyl ketone 80lutions by OS-pereent H 2SO in 95-pere(lIIt ethanol to umollnt of resin8 udde(l U8 indivute(Z by colorimetrio readinU8
(Rubber ami resins cnlculntcd on bnsis of amounts in 5middotml ullquuts of extract from 02 gm of tissue in a 2fllll olumo( bull
Hubucl r~cocrell whcll rcsins nddcd as IndIcated Htbbor al1dcd (pllcollt) ---shy
__________bull_________ ~_12rpcrc~15011crccllt 7511crccnt IOOpcrcent
PerCtllt ercellt Percellt Percellt Percent o o o o o) 50 250 263 252 25000 500 500 500 500 700 750 750 751 749
1200 1250 1250 1250 1250
EXTRACTION TEMPEHATURE AND TIME
Typical experiments to detllmine the time required to secure maxishymum extmction of rubber und ltsills at 115deg U Ilre sUlIlmarized in figule 13 the solvents used-methyl isobutyl ketone for rubber anrl Ilcetonylacetone-cellosolve 3-7 for resins extraction-are very eflicicnt since under the conditions indicttted maximum values were secured after 30 minutes of ext1llction The most eflicient liquid for the bath (lig 1) used in extrtlcting rubber or resins is ~ high-grade cylinder oil (S A E ~O) The sand bath and such liquids as glycerol have proved unsatisfactory
RUBBER AND RESINS STANDARDS
According to the National BULeau of Standards 1-_ lhclc Is no gellcrnlly recoglllz(d standard lIIutcrlul [ior II rubber standard] The rubber hydroCllrbon ill llifferent samples of conmlcrciul smoked sheet or pale crepe from heclI pluntlltions nries from l~ 10 04 llercent of the totul nutletmiddot the most 11Ioruble conditions Of preparation
McPherson () has described a procedure for the pLeparation of pure heve~ (Hevea brasiliensis (H B K) MueH Arg) rubber from crude rubber or latex In the absence howevcr of ~ generally recogshyn12ed stalldard for rubber hydlQcllrbon [caoutchouc (CnHUs) xJ the standard adopted was that of the relnthely pure product secured from gunyule tissue txtractiotl nccording to the Spence-CaldweU method (5) or the motlified PIOCCdUlU of Hohnes lind Haasis (p 2) The details for constructing the calibration CULes are given on page 10 Standard rubber samples apparenl-]y can be stored for a long timc under the conditions des(libed on page 10 The duplicate colorimetric lendings for glULyule rubber newly extracted by the modified SpenceshyCaldwell method were ()J2 ench as compared with US) each for the sample extracted by the same method but stored 1 years In each case colorimeter rcadinllS were made on mixtures containing 2 mg of rubber in It 25-1111 Yolume
The selection of tt suitable standurd for guayule resins presents some dilliculties Tll(~ acetone extract of gUllyult estimated on (l gravishymetric busis~ for instance proved to be variable depending on the type of tissue sampled or season of sumpling because such fractions as
COllllllunlcntion dul(lt1 Octohtr 22 11H3
28 QECHNICAL BULLEQIN 920 U S DEPT OF AGRICTTIIlURE
16~==========================115 shy
14 bulli= 13 z ~ 12
ffi II Q
10 c w 9a w
8gto () 7w a
6a w
5en III ) 4 a
3
2
A 00 5 10 20 30 60 90
14~------------------------------------------- bull13
i= 12 z w II ()
a 10 w Q
9 c w 8 a w 7gt o () 6 w a 5 If)
z 4 If)
w 3 a
2
o+B~~__~__~____________~__________~ 5 10 20 30 60 90
HEATING TIME (111 NUTES)
lllGUltE 13-lDffect of time o( lICntillg O2-gm samples of gunynle tissue with solYlIt nt llfio C on lo(OVl)ry of lllhlJer alld 1Isim Lt HlIhblL extracted with methyl isohntyllwtone B resins Cxtll1cted with aCftonyla(etonc-cellosolve 3-7 bull
chlorophyll are weighed along with the resins in the acetone extruct but are not estimated by the present photometric method (fig 0) 1he use of a diffeJent stanclttrd waS therefore indicated
bull
bull
bull
RAPID PHOTOMETRIC DETERMINATION OF HUBBIm AND HESINS 29
The resins standard selected is based on n relatively pure source of resins the rcsinous exudnte 011 the stems of guuyule plants IJldimishynary expeliments with the resi nouS cxuclate from diffcrellt gllayu Ie strains of various ages indicatc nHlt there is little YaLiation in this subshystance on the basis of Colorimct(r readings 011 2-mg aliqllots of 01shypercent solution in It 2i-ml volume (tabl( li) Expelilll(lnts have shown that the air-dried (xuclate contains 3RtOH p(Ic(nt of -volatile matter This material is l(latiyt~ly stablp ill (OlllpoBition and is npshypurpntly on ly slight ly hygroBcopic as shoWIl ill Ia bl(1 1 Tlrp Ipsinolls exudate may be jJleplpd in two wayi-i fl liSP as a stallClHld-(l) the clpan exudate is clripd iol Ghouls at ()1deg C at W indlPs of a(lIum Hnd aftclbCinOglOund ill a molfalis 1)I(spI((I intn airtight COllilinel OL
(2) tllP Cx7lclate is clissolllt1 ill a(lhllll and filtplpd PlactieaJlyall of the acetm1l is thpn lYapolntwl olt OPI a stlam or atCt hath and Ow residue is dripd ground an(( PI(sPIld as ill tllp fin lllethocl Tlwse two prepalHtlolls a1( (ompalpd in ta hlp ) 111( (((tails fOl ~t()lil1g the resins standald and (onstlllcting the calibration CUITPS alc given Oil page ]2
lAIIIg fi-CUIIIllrsoi (lJ lIr-dr(1I IIIIi 1((11 II II-()I-tr((l l(sil~ 11111111(8 of I II 1111Ie
[Colorimetric rrndill~s 011 1~I11 phulll(Iclrie eolorillJct[lr with i~()middotmll (100- to iiOIIIIl) fillcr [lnd 5-1111 lIperture preeipitantl part ofO5middotPIrctllt 10 to 5 paris of IIOj
nupliclllc(oloritwt([
nIl(lin~s (hIlSlcAg~ ofSlmillXo JrNliltlCllt of fPsiJI$ L1Xtlrlntp on 2 IIIg ofplanls fllsins (XIHIIlt~Jwr 25-1111 vol
tII1(1) 1
leflTs Various _ bull ____ bullbullbullbull 3-9 Colll)Josiltrlairmiddotltlricfl bullbullbull nf)2 002
])0____ bullbullbull _bull __ _ bullbull ~-l Composilld (ri d at n5 C in aUmiddotimh lWUUllJ for l (jOuj(ja hours])0______ bullbullbull __ bull ___ bull 3-0 COJIlpositld disso]NI in neptolll f1l1erNl fl(lf()ll( GGO i(jO (Ivaporntld olT OV(1r Stpl1l11 halh TesidlH drl(ld I1t fi5deg ( ill anmiddotinch VIl(Unlll for 0 houlS bull
middot106 __ bullbull _ Jir~c1rild_~_~_ _~_ ~_~ _ ~ ____ _ __ _ OUu GOifina_~ ~ _ ~~_~ ___ _ _fln~ ~~ ~ ___ ~ __ 6(imiddotI tiliA H)[_ ltlu bullbull i18 tisSflOabullbullbullbull__ bullbullbullbullbullbullbullbull lt10bullbullbull _ tillO llitO406__ bullbull __ bullbull __ bull __ __ lt10_ Utl2 fon591_ fo__ bull liGa oOa 406bullbull _ __ lt10bullbullbull_ li5S OM
j Ph( vnluls in Uw Inst COIUIIlIl indieatp thnt gunyulp fesinous (IIHlnt( wlwtlwr dfircl hi Yn(tlLJ1l1 wilh L~ perc(nt loss of volntllt wutl pr or tWl c1rild giVPd npproxil1lnh1ly t Iw snllw colorinwtCr rNHiing- 011 till busis of aliquot~ cOlllniuiug 2 IJI~ of flsillS lXIHlntp l)tIf 25-mI volultl( Ihil- illdicate~ thl11 Uw UITW IJ1flS~ of olnshytile mntl(f prt~(iJlitnt(d gins npproxilllntlly Uw $1II1l (oiOfirnl1tlf ftudiTlJs ns tho ftsidtw A pnlill1jllaf~middot (XIlltrinllnt indicutls thlli th VUllltill muller l(lIlSists of thl Ilrplne oil fmcl ion I5-(1Il gtnplls or rlsitlOtlS (lxudntll gnvll by stPll1U distillation nn Uefllgl of 011111 of jl(lfPlIW oil with npproximHte tilllsity (If OHIi lind lhus rrprlsll1ll( IlPIJroximllt(I~ 01 Jerccllt Of t he original weight 1hls lllrClnlage complrcs wllh 38 llltrC(ntlost by drvinI( in IICllnllJ
aSplusmnUH perceilt or orlginlll weightlosl
The wailnble illfolJllntioll on tlH (ow-JitlPllts of the gunYllle r(~shyillOllS exudate alld tl1( HeetOlIP ext act of gaylp ti~slw is sllIllmarized in this paragraph lYalttI (u) alld also Hangcn-Slllit lind his coworkshyers 16 reported that 20 percent of the resinolls exudate from gUltyulc stems is parthenyl cinnamaie (CHuOH=CHC020 11JI2r) Steam disshy
15 (OIlIJIIIIUicatioll flom A T Haai(II~l11it llId (0011(11 Calif0111 ill Tnfiitnte of Tccllllology Past(IlIJI Jhps( wOlken al Htud~ing the COTlHlitlllllts of the acetone extract and other conlltituellis of guuyule
30 TECHNICAL BULLETIN 920 U S DEPT OF AGRICULTURE
tillation of similar resinous exudate in the writers laborntory has yielded approximately 4 percent of the whole as the telmiddotpene oir fracshytion Haagen-Smit and his eoorktrs nportec1 thttt about 25 percent of the acetone extract from guayule branches is parthenyl cinnamate and 6 percent of the bark (ltortpamp-phlotm) extraet is parthenyl cinshynamate These workers fm-thcI reported that 25 lwletnt of the nc(shytone extract frolll bLllllches is a compound with the tlI1pilicaL formula CBoH400a 1 percent is a compound llwltillg at 2P to 2T5deg C and 1 percent of the extract from the ]eav(s is tl (olllpoulld nwlting at 100
to 1710 1Valtei (6) reported that 3 to -l perc(nt of the tI(eton( txtract
of leaves and flowering StPIllS of guayulc eonsists of waxlike substances soluble in olgallic soln~nts but insoluble in at(l and (on(ent1llted H 2S04 The flactions mentioned on the basis of (onHLTutle esti shymates of amoullts actually isolated tlecoullted for about H ptIcent of the totalncetollt~ so]ubles extracttd from tll( guuYllle 11 rub The other constituents ltlilaill to be i(](ntifi(d
RUBBER AND RESINS CALIBHATION CVHES
Typical culibndioll Clllves iol Iuhbpl and I(sins bas(d 011 (ldtLminttshytions made nccoLdillg to the plocCdmC outlin(d 011 pages middotb to 1G arc shown in figulPS 5 and 1+ The spCdlopliotoll1lttL en (OIOIjlllctCI readings are plottCd on s(lIlilogalitllllliC pappi ag-ail1st (Il 11IbblI (011shy
100 ~ 90
80 ~ 70 ~
z 1amp1 0 II 1amp1 IL
1amp1 0 Z
60
50
40 ~ltI 30 ~ en z ~ ltI II ~ 20 C) ~ oJ
10 o 2 3 4 5 6 7 8 9 10
RU8BER IN 25-ML VOLUME (MG)
bull
bull
bull FI(lURE 14--Ctlihration curve fotmiddot gllftYlIlc lubb01 (Hct(lings Oil COIPIIHlII tlOl1hl(
monochromator SlCClrophotolllet(r with 7fiO-11IL Illtel alld Hllp Wll ( IHlll()
bull
bull
bull
RAPID PHOTOMETRIC DETE~MINATION OF RUBBER AND RESINS 3]
centrations From a casual inspection of these CUlTes it would appeltr that Beers law does not hold Actual tests indicitted that Beers law was applicable only within a narrow range in the upper portion of the curves The analyticlil results on the basis of photornetric readings nre therefore calculated by direct reference to calibration curves or from reference tables of equivalent values bllscd on the cnlibllltion curves
Calibration curves for kok-saghyz alld heyea lI11tulltl rubbers and Buna S (GR-S Chem Gum IV Goodyear) and butyl (GR-I Standshyard Oil Co Protoc) sYJlthetic rubbers are hOWllil1 figure 15 The samples of kok-saghyz rubber were furnished by the Diyision of Rubshy
100
90 ~I) ()
z 0
1amp1 a
~ a
80
70
60
s 1amp1 ~ ~ 0 ~ KOj-SAGHYZ 0 l Il
50
HEVEA~ ~
40
100
90
~ 0 80z Q 70a Co)
a 60 ~ 0 0 x 50Il
40 ~----~~----~------~------~------~--~ o 2 3 4 5
RUBBER IN 25-ML VOLUME(MG)
FmUIlE 15-CaJiblation curves fOl kok-snghyz h(YCII Bunn S lind butyl rubb~ls (Readings on gy((yn photoelectric colorimeter with i20-lIIp filtpl and 6-ml aperture)
32 TECHNICAl BUIJLETIN [)20) 1 S DEP1 OF AGrnCUIlfURE
Iwt Plant JIl(I~t ignlioll of thi BlII(un and (1( l))(parcd according to 11( SPltI1((-Culd (]] (6) PIO(((lllll Hlpt pal( CLPPe was (xtmch(L with acetone blI()Ieit W 1I(gt(11l a ttnlldal(l
SEXSlllVllY Ol~ llETJIonS
By lip pIO((l(II11P olltlillP(l 011 ]Hlg( +n Iowa (lOOl IIIg (11 1111i(l0shygmm (gHlllllla) of 1hblI ill a 2)1111 yoltll1ll (all )(gt dltpltld Oil tltl Col(man (lohlP mOIlWhlOl1lHlOl l-I)((t 101 l1lOt 0111 ci( I ill1ilnlly 001 mg of Iublwr ill a 2J-1ll1 n]ulllP Illay bl Ilad Oil till EnI)1I photoshyllectlie (O]oLillllt(I Thll ya lllll- 011 tilt IHl-i- (J I (xl ad iOI1 fmlll 02 gill of til-lI tH(JI(lillg to tllP -lllndal(l jll()(pdull 1(PIPStlIt IlO()2J tlnd 002) P(IT(lIt of llIbl1ll IPI)(((inly bull1t1lollgh -lI1t low allils can be d((d(middot(1 il lIoullt1 Ill IPtllizpd thnt till PIIOl ill PlI(Plltng( or tll( al110unt dltlIllIilll(J i ltlatlpl high ill tili PIY lo Itlllgl 111 aetllllllladie(middot Ill( lopl lillliL 111)(1(1 lIw (ollllil ions of tlil ]lI()(lltlIIIl u ol1tlinpd ipt at l11 11I1 or 1111gt11(1 illt i-1ll1 Ollllll IlPIPltPlltillg 01 p(gtl(pnt of JllUiJtL un tlll 1Hli or (xlla ion rlOI11 II rlll of tisSIll
EIlIlOH COSIIlIHIIO
In Oldpl to H(IIp ill )1lHtPltt pl((iioll illlpIi1I- it i lH((SSHI to slnlldHIdiz(i rigidly 111( Pl()((dlll( 0 illdi(ntpd Oil pnglt- - to J( If lids i dOlH tlip lXIHlinwnlal PIIll is t(middotdllld 10 n ndninlllill
Illlt pl(iioll of (hI ]lIPPllt 1IHllwd Oil til basi of ]llllP llIllJt1 alld Ipsinssollltions call hI jlldgl(J 110111 figllll Hi lileh lio- til HPIlIgl d(intioll oft -illgIP lI1lnSIlIlIIIlnt in lHi((lltagl of Ill( alllOllllt 01 Illhshy1)() 01 lpsins d((PI1I1 iJlld TIl( (1101 PlI(Plltaglt H1( gi (1 101 OJ) to
RUBBER IN 25-ML VOLUMEMG) 004 01 02 03 04
i= I I IZCtOW
fbA ICtU CtCt WW a
01 02 03 04 05 06 07 08 09 100 = RUBBER (PERCENT)
RUBBER IN 25-ML VOLUME (MG) 10 20 30
~ I CtZ
bBOw Ctu CtCt Ww o I~
010 50 100 150 200 250 RUBBER (PERCENT)
RESINS IN 25-ML VOLUME(MG) 10__ __3-0_ 40 50 60 70 60 90 100--_-- 2_-0
Ct~ -r- 1 I OZ
WCt UCt b C wCtW
a o I I 150 250
RESINS (PERCENT) o 10 50 100 200
bllI 1tI W-Yllnl dtd1 ioll I I 11l1 11IlI11 1(111(11 1 III Plll- IlIIIlol1 01 IIim~
bull
bull
bull solution Il basis J o golH of tiSSII (JlILCl-nt (11(11) for (~I) (l)1 til O 1I1
of luhllpl lin 1 III I (I Ill of lUhlJPl nllll laquo I J to 111 nlg of IlSlllgt (Itllillgs on ]iYllyu pllolwh-llrk CO[IJlilll(-(PI with nOHIP Iiltlr lIntl U-lIll allcrture)
RAPID PHOTOlJElRIC DELEHlllNAllON Cn HUBBER AND H1~SINS 33
10 mg of rubber anel1 to 10 mg of resins in a gJ-m1 yolumC For
bull
bull
bull
comparative ptuposes the leslllts arc also calculated on the basis oJvershycentage rubber OL tltsills in 02 gllI of tissul As WOlllL be expcet(d the error increases sOIlHgthlf for 1(lali nmiddotly low COlHell t1llf iOlls oj rllbbeL or resins The curves in figure 1(j s1l0 that ill til(gt Illlge Ol to 10 pCrshyeent of lubber the elTOI rangts Jroll1 abollt Ll to II) ]IlC(lIt abo(~ this mlllc tIlt (ITOl d(((ts(s to (ollsidlItbly ltmiddotss (han 1 1lICPllt of tlH mllollnt ltl((Lmill(d Hil1lilally in tlH (lISl of l(sins analysis (fig 10) the ltLTor is (onsit1eIubly INS than 1 PlLllnt ill (he lallgp of 11 t~) ~() penPII t
In nil ([lSl of lllhblI alld (sins lx(Inltpd tIOIl1 (issups Ol addcltl to tisslle lxtlads (s(( tabhmiddots (i H) illyolillg ll01P o(lllntiolls the eLI01
is hig]wl thun that indilHtld in figllll ((j Im pUIl Ill )])p I tllllllsins solutlOII
COlllUCIIOXFOH IXSOLl-IlLl~ Ilgsqgt(Jg
111 th( Jllo(pdulP ollllillPd 011 paw I till illsolllhll isSII Ipidll( tflpl (xttlw(ioll is (Ptill tlw lIask l(lll till xtlct i l1wdp up to yoltlllH It is not rOllPllipnt (0 IPt()PI qWlIltitati(Ir III(lw[olH a 11(1 pllooll extlnlfs of guuyull I is-lll alll thl1l main t11l111 up (0 YOIUllllmiddot bpCaUHI sllch all additiollal stltp wottld]) tillll-C(JllS11ll1illg Th( Iogiea nll(gtIshynntin is to mnkp tltl lXtlUCt Llld Ipsidup lip to OllillH in till original flask andi llPSStllY 10 llwlno tl OIIpdioll wlHIl (allIlnting [hc llshy
Hults f(JI [hl oll111lC displupd hy till ins()lllbh llsidll( III it l)picat (IXpednHllt (ollsisting of Jhp lppJiea(iolls if was Iollnd llftt at ~iiO ( 02 gill 01 Iuhhll pillS IPill-fl(( lisslI(gt (lollpdll fot llwistUlC ou basis of dlyillp ut lOW 101 ) llOlll-j (lbp(ld only t~ llllUll voiul11P of OOk7D~- OO(lOO(i Ill of lllthyl bolnl(yl 1lIOll( (lplhlli(al-t(Tnltle sp gl () Ii I ll(Hli (j at ~)) -gtitllP tl1(gt 1It101111( () r t is-lIl xt Iadld j sl1lall til( PlIOI dul to Ill(gt insoll1blp Ip~idll is slllall III [0111 ill( wOtk it (all lJp diIpgal(ll(l
]hcon~lIY OF HllIllgl AiO HESIS AIH)gl) TO EXTlIACI OP
GlYlLE TISSlg
Tnl)ll G L(IHpslntillp (ypi(nl llld(~ SllOS (hat all a plngl of HIOK PlI((nt ot lltl pltl( Ilhl)(l acldpd to tllP Itll h iolJut1 InmiddottcJllP xhnet
of guayulp tiSI1( WllS 1l((PllIl Tlli nllintioll flOlll (olllplpU I((OYshy
PIY i within flll pxp(IiIlHuttllIIOI ~illli]llly fnbll Ii llows thn 1111 llYlIUgl of 1O(1~ ])(I(Pllt of gllllYllII 1(-i1l- add(d to II( (pllosol( (xshytrae of IUllY]l t i~HI Is 1l(oPIPI
THl~ (~ Hf (Off Ill of 1111)( J OJ I~il~ lItfI(( In ~(JI1IJk~ Ilf (111 [lI1Il fI2 lIII
0 tlUfllllit i~~I1
Instrument
---- ----~---- bull shy 1(1
Colemun ruono~ltrOUlllt()r 2t) II sJl~ctroJlhOL()lIIeter with 2tJ I iflllllI wnclength Fetting 21 II nntl 0-1111 WU HI hUJl(L _ L U
Ill 7Evolyn photo~lcclrie (olor JU [ imctcr with iO-llIl filler IV (I
H1 0 t I I
llImiddot lUn WII 1011 HIO Wn mil lUulon
10 JIg1111 IUI ml lUl anh Io aLn 111)_I ) III li lU It 2) deg wn2SU DD
Irl JIll II IIr II US II
1110(1 lULa lUI IlK) IJ WU
I( llI Htl tNI 1(111 2tlNI HI 0 221) lllil t2S 0 1~ 10 1~13
In (I 2117 I
10U 1l(J ~ 4 _H_j ___
9middotJIlJ5 10115 10 00 lUU5 flUU 4li (tl03 9(11)
leIlKl 1l~)5 lOOU l1KIr JOIS un 003 OIl Ii
34 lECHNlCAL BULLErIN 920 U S DEPT OF AGRICULlURE
COMPARISON OF PHOTOMETRIC A1D MODJIoIED SPENCE-CALDWfLL METHODS OF RUBBER ANALYSIS
Guayule samples were analyzed by the photQ111etIic method and by bull the modified Spenc(gt-Cnldwell mcthod The values in table 7 represhyselltativ(I of typical results indieate It -atisfactory dcglpe of conformshyjty between the two methods in thl range of tiSSlHH with llHHC than OJ) percent of rubbtImiddot On the bnsis of the amounts determimd the results in this runge for the plmiddotts(nt lIlcthod ayernge apploxinHltely j percent highcr
~LAIII~ 7-(oIllJl(i~on of lltlllrIic (IIri mOtllinl SJl(II(r-(ulri-wall IIIrtlwrl~ of rlrrlIIillillfl 11)1)(1 COIIrll of UI(III
1 Flowers frllm amiddotmonth-oltl nursery plants
YAIIIATJO- OF SIli(LE DETEnt1NATIONS Fnoll TnEIIllIEAN
Rllbbel (Uall8i8-Thc plcCision of thc pLcsent method when gunyule tissues Hr( nnnlyz((1 for rubber may be j udg(d flom I Ill datil presentcd in table H TIl(se dahl -how that thl pplCPlltag( uriation of single determinatiom from nwan yullles with low standllrd enolS ranges from less than 1 to 4 p(gtrlent
R(8in~ wWlsi-r-s lndi(a((1 011 page ~j he INntlts s((uled hy the present phoolllttric nsins llHt hod are not tliltly (olllpalable with those of the grtLVimetri( ncetol1l-cxtlt1(tioll II1etho(l Thjs made it necesSllry to selc(t another lalibllltion staudud-tlll Ipsinous exullate from gullyule shrub-thut gies relatively COllstlllt photometric readshyings (table 5) The resin (olltents of guayule roots branchcs or leavcs usually ran(~e from about) to 1-1middot pelcellt The ple(ision of the present methotf WhCll gUHyule thslllS lIe analyzed for reins may be judged from the datalHmiddotpscllted ill table 9 1h(se data show that the p(lcelltage variatiun of sillgle lhmiddott(Lminntions iLO11 meun ynlnes with low standard NTOrs rangcs from about 05 to 4 percent
bull
bull
bull
bull
bull
RAPID PHOTOMETHIC DElEruIINAlION OJ RUBBEH AND HESINS 35
IAIILE 8-luriation inclieute rubller (mallSM of [1wIIle tissue bll thc 1111O0Illclc metwII
Vnrlntlon~Ilbher I (rom mean
ierCtnl Percelll ~OU -22 ~ 25 +27 ~ 20 +18 ~UO -22---------1_______ 51110 0G6 bullbullbullbullbullbull _bullbull
10 ro ----=ii41075 -01 1000 +11 1010 +13
rlln HI itil 1l9~ 1_ ___ =-~~~
115511 ~ US -111 III II 1575 -13 115 b tiS -I a 111 h WlU +22IIM-(middot bull 11K -1Ja Illi c 1000 +03 1J5H1 W +l)7 ll1imiddot tl 1575 -13
Mcnn 15951 131
1102-11 21fJ() +21l102-h _ ~~)SO -17 1102-c bullbull 21CO +21n02middotd ~OIiO -26
2 r~plusmn Il~ 21151 261 I -~-------bull---__ _~~_~______l-___--_
1 lhe$ 1111($ I1n (or SlIlIIllltS Stpnnltplr PHrilClld IIrtlrdlng 10 1hr prollIlIlr( OIiIIiIl(o(I on Imgt$ 4 to IC ~tcond nUlI1 hlr r(J)[ltnts stl1ndnnl llrrot of tilt 1I1(1111
1_1l1~ n-J(lri(iot in relli(Upound rpoundsins (lllalIsfs of VIOJII( lixsue b1 the lhomillric lII(lloli
-- ---~--- - __-------- shybull I I I I Varlgttton
_________~___ ~~lu_n_Jl_Q_~~~_____ ______I__~_o~S_J frOID lDean
Percent Percentgt458-1 ~65 +41IWtl-li 130 -a2Hli8c aliO +26S41i8-d bull 130 -32
1(-011 34I10Olifgt __ bullbull __ ~--====
li-9~2n 881) -06 li-9~2-b Si5 o ~HH2middot(middot S i5 -6$-H2middotd 000 +1
8851 054
O i5 +6 9 i5 +6 950 -20 U75 +6
H-liG3o-n bull -1 n-li6~b bull __ _ -IH-IWH +4H-l61511 bull -1
1tmiddottlU
62~-lI __ 62~-b ij24-( bull OH-Ji
(-Ull
I rll(St oluls nre tor separately ~xlrflCled SllllllllCS IlctOrdlug lO procedure outllned ou pages 4 to 10 i Secoud number r~prtgeulS stulldMd error of lIe menn
36 TECHNICAL BULLETIN 920 t ~ DEPT OF A(]RICCLTCRE
ReUUER A~ALYSrS I~ CRCOE-RcuUER PROOCCTS
Sew rapid photometric m(lthod~fol the ddellllinttion of rubber and reii Hi ill uaYllp ti--ut htp lllell pIPHnl pd oil pag( ~l to In A brief H1111111tlY of It similar rnpid llHthod fm 1I1hb~rllnltlysis of u1lulcanizNl tlIldp lubbll pl(Hlmtlt whielt i~ bn-(tldo on the prill o
ciples dehtilcd tlllLe follows Duplltate nt-gm sllmph of the finely cliyiliNl IlInttlitiup wlirllll out [~ei-()l (all hl lIf((tinmiddotjv INd to lt1iyidl till alllpl) TIll kltolll-olubll portion of till )111(11( tlrc di-olved a- indh-Htpd fot thmiddot lllnkill~ of -tlllHlunlluhhll olutiou Oil Pt 1II hut tIl IUlIp Hn lIn l-fplImiddotd 10 lHI-ml rolllllltti( fln-k antil1ltld(lup to Olllll1l The bnlulUp or till JllO(ldllll i- thatutlilllll on paWs -1- 1 IHI Ii 111( 1(111 1- nIP IXPIP--pd nil til IHi or Iw oligiJla w(lullt of I Ill (I11l1p-I1l11Ilt1 1)(0(11(1
Hupitl PlllimiPJojgtiWllllllllh llIltllOd~ fOJ Ihl llPtlmiddotminntion of ImiddotUlJbll tlnd 1(-illo- ill -111111 Illllph of gutlYllll tiUl IIll dl-eli)ed 111() IlltlY d~o Ill nltlI1lld fOl III Iwl Illhlwl- and l~iJlmiddotb(lLiJlg plant TIllt l[Olllhup hns nlo b(l1l ntuptpl fot IIH lltlIll1illtltioll of lllhbpl ill 11lHhrublwl Pl(Jdlld~ HIIl 1111 hI ndaptld JoJ IIll ann lysis of ynt1J(gt( ic lllbbl[- The llllthmb HIP 1gtn(11 fill tIll fol1owill plimiph- III Grinding
tIll PIOPlly driPl t i~lIl 01 Ul tillg tIll pnHhHt to tll l((lllilllllh~lel of filWlH-- til plllllit qIHlIllilnth( lXIIHtioll 01 IIlbhlI 01 1(--IJl- () llsing oXWllutld olnuh (kttoJls IIt(talp and() fllltil for LIbbel and IH(ltIlIlyptIJllIllIoolYlnJld-o flJllh 101 niJlsl with t(lathelr high IlPililig points 111 to n C) l]olle or in mixt tIll thllt Pll mit tlll rnphllxututioll of luhll(l OJ [middot(ill ill ~() to (l mi1lutp It r(latiwly high 1lllIllllltlltP Ill to 1~11 ) l) lllllipitntillu till luhblI OL Imiddot(ill frolll aliquot () f till oltn ion I IlIlllI-i () f Hlltabhmiddot pl(~(i]litallt (willifhmiddotd lthmwl fOl IIlhlHI Hild llitlifild lllr fOJ JP-illl t~) IIlHkillphotollllliilPIIIIiIlof PlllPlltal of liht tLaIlS mittUl(P lIftlI IlIlbll (II Il in PIlipitalioll 11 II WI( Iplllh thnt (limiJlall till PIIOl dill 10 xtralllOlh (0101 (till dptl1minntinll Iph jill 011 tIll dtwlopllIlJIl of H HIli rOI1ll tlllbidity 111 hpl than I (olot rI
jJlIlpOP-ofallnlyi-I ( p(lllil1thb IIllijOI1ll turbidity or 1llt[lIinmiddotd d(ltl of jgtIp(ii(JlI l)~ lIltlkillU tIl plllltollllmiddottri( ntdillU al tandinu tiJlH~ (dlllilll wlli(h IhlllH(lill-- IP 1llutinmiddotly tnhll) t1ll1t an hlsl~1 oil the (oJlItlIlllItion of IIlhlHI Ill I(ill (lIPIipitat((L
TIll -I(p ill till jll()(Plhul HIP 1-- follOylt (1) 1l~UIIL uJ1lplls of thwl UJfJlllHl (II tliddl(l HUt dlipd 11Illtplial an lXIllltel with11 Ill of till nlnll ill t (oU tlllltIPlll[gtPImiddotatlup oil Iath at 11 Cbull fol 11 minutl I) iIP1lIin(middot(lohd til( (XUtllhllll Jltldl lip to It middotml ynlmlll til( (nlifild by (Illlifllgiuu HlId thlPl IlI nliql1ot of tIl (IalioPlllxUlltl nll Uillltlmiddotll(t to l-llll OIlIIlIllril fiuk- (1) For a trial Ilnditlg 0111 III tlll j liJmiddot~t IllHII IIjI to Ohlllll with lilt Pll shy(ilitnnl a 1(11 it 111 (Dod fill llli lIut ( ptotoJIIltlil IPtlllillg-- of pllllntnl or liuht tlUtllIlillal(I oil n (lpel OphotnJlllllI at rase hng-tlt (If 11 llJ Ill Ol It lollllil1lPtImiddott lloyidld with tIll P10]11 I 1110110shy
Ihlolllltt hmiddot Ii1llI Olllhi lIatioll for -1IpItillg UJlproXilll1l tply Wtl P ]Plwth )0 mp are HHlltk TIll Illldillg lliJtaillld fol tIlt 4-milutl tliall(~ll-
bull
bull
bull
RAPID PHOTO~IETRIC DETERIINATIOX OF R(BBER AXD RESINS 37
ing are referred to a table of equhmiddottllut~ previously p1(pa1elt1 on the
bull basis of 4-minute reac1inJ~ for tilE nmge of lot1telltlatiol1- of rubber or resins to bE elHOlll1t(led tmd gidn thtmiddot -tnnlillfr tillIP fill rUbbEt or resins aiter prE(ipitlltiol1 lwfolE photoIllNliI j(tltlill1 un IUade The r(middotnmining dllplllatt aliquot lll then HHllil up te ol1l1Jle and lpoundadillg ale marle ut the -tandillfr tiUlE iudklltll ill rhl tall1lmiddot for the final r(adillg~ -1) 111( milli1lnm or p(tCPlltllt- of lllhbpL (II 1(-in pr(s(nt are rpadholU a prlpan(l table of lquiltlput for tlll photoshymetric readings h1~l(l ill pnell e1-E on pxpPlilmlItal lhln 1111(1 u-ing as stimtlltlds pure luhbll in 1l1bbtl milllYb aIHI guaYllh ll-ill- lxIHlatt~ in resins detNIl1111lttion I
LlTERATlRE CLTED
(1) lUnSbull 1fl36 THE mURMIXTIOS IIF IOTA RE I III OOl THER llT~II
F1 bullrol IlY U(T1l0fll UfSlfi ~rrnrl r flm lt1 KEYS TI Bill Chern 114 44J-l59 illns
t1 ~ICPHHlObullbull T 1J3bull~ lUTHOO roa THE PtRInCAnu Or a(lIUl IRrIlHU It of TIn
PLRIHEU Htllllflt [ i Bill lallllall 111 Rmiddot 711middotj iIlus
I ) RHBERG P B Ul5 A METHIlO Or ~u(ronrll-nl Hi tIII rUIl[1 f71 ii illlI
bull 14 Hoss W flbull and HARDESTY J O
llH IR1ltDII Of HfITilIZfmiddotR DllIJS ltt 1 Yl fll Off gI bern JIIIlI i ~middotmiddotlf IIl
101 SPEltCE D nnd CuoWELr ~I L 1933 DETER~n-ATIOo OF RtBBER Ii nrllllpoundRBfR Iusr 1uI II1 amI
Em~ifl cttIliIa~~ r Ell i 71middot7i l11 (HI WALTER E D
1U44 ISO~nlS OF PRTlltSrr 1trHpoundV bull l UI n W lHHt (Tnmiddot 1ETS FROM GiYI l~iIl lItr Clttrn SII J UI titJ middotn9--C1 ilIu
17 J YOEbullbullr H lO~( roLORIlETRT 771 IPmiddot nl -W Yurk f H Plrwptric hmica
naly-II rimttry lUll XphHHlnmiddot~ y 1 1
11
HI) ~ fPHELolzTRf 57 111bull Lin xw Yk t H lt PhmeHt CblUlmiddot ila AnaiY~l~-(H lithrry and XIhmiddotILpfIY Y wirh enomiddot rrJlllrjr hy H KtlJnJU11 I
t~1I --- and ~ARVER L 1f41 nlua-w ~in L liLhr IS IP ll~ XIW Yrk
bull For-sale by th~ ~a~fr1nt~nf1ent Dt~c~~ogtnts-~ s t1i rArnn~ut Pn~~~ tJffieshy
Washington 5 D C bull Pl lU ~nts
20 TECHNICAL BULLETIN 920 U S DEPT OF AGRICULlURE
Even with screcn No 2 difficult due to rnbbel tlcrltreCtlltiollS may be ob tl
encountered In thes~ caHeH it iH lWit to parboil the shlub fOL leaf lemonll and finally to dry to about 1 to ~ P(l((llt of tnoiibl1(l pound01 b(~t results jn ~rindillp in tlH hanmHl mill
It iH aclvlsable to provic1l thc hammer mill with a ground wire Hillel the presence of static electric (harges 011 tll(middot partkhH will ealls( Home of these to atlhelc to the inside of tllP (olltailWr OJ lila eallsc OI1l( of till pULticl( to form ngg1(llatls EIIolin lalllpling fl01l1 fhis SOI1I(I mlly be (onsi(h1llbl(middot
A1I10l1g the Holnllts with high boiling point that lIlay Ill IlHld in rubber anal)Hs I1IP Illllhyl n-alllyl ketolle methyl ioblltvl kptOIH diisobutyl (tOIH blltyl tHptate llethyl amyl 1Ittail (middotthyl(middotlllmiddot gly(ol diethvl (middotther and n-bntyl (middotthel (labl( 1) TIHse al( also I(sin 01shy
middotent but th( 1(~illS n1( held ill olution by the rll1)bpl pl(l(ipitant tthanol wll(1 lllbb(r is 1)J(lipitatNI (S(ll tabl(s alldmiddotl) On tIle basishyof the lxpHilllPlltH tll( btsf nil-round lolPlli -rol lS in 111( PIlHPllt method is lt1iisobutyl kPtonc wld(h was not IIltlllllfaltllllmiddotd ltIlling Vodd Yflr n A suitable Sl1lgtstit ute iH llHthyl jolllltyL htolt whi(h is l(porhd as llolltoxit UJ)
Clllos()IY(~ (ethykn( glYlol monopthyl (tIH1) blltyl earlgtitol (di(thyl(ll( gly(ol llIollobutyl (ti1(r)~ and acttonylacetOll( may be used as resins sohrCllts (table ] )
In the earlipr work with (sills analysis cpllosoly( alolle was selcmiddotet(d as a suitable solycnt Aitholllh (ell()~oh( alone is pxc(lllnt its rplllshytiwly gwatlL iscosity 1(I(b to bubbl( formation nft(I (SillS pr((ipi tatioll Thi- increased thp (xperimentnl (LTOI OIl of tltp othll I(sins solpnts tI((tollyla((tolH has the proppry of glpatly lNlulingshydH(OSity 11(11 altld(( 10 othr liquids This sohpnt tlHIeforl wa addp( to ((Uosoh( in slIflici(lJlt tlllIonnl to OPI(0111e the dinieulty On the basis (li~ex)le1inwllts ~ purts oi~ a(donyla((tOlll to I puts of (elloshysoh-f (bolll by olume) as Splldcmiddot(l Thp 01 hel Hoh(nl listed hutyl clLlbitol at l(llst the t((hnieal-g1lld( ploduct uSNl is appal(ntly not as good as eithe of t1w ot1(r two () a (ombinatioll of tlWSt
The SOlVllIts JOI liSt in tumlyzing artifkial lubbel$ hy tlw pr(senf method appllLently (lcllIHl on th(middot kind of llI))(I lIp-ityl (Jxidt is suitable Ol BUlla fi and hutyllthlI for butyllllbbl Tlwse reagents IlLe technical g1lld( Calboll amp CtllUil1t Ch(lllilai (OIP This Hllbjp(( hilS not bepn (XtpllHl(ly illwtigated by till WIit(I
PIIECIIIIJ-
All tlst fOl Ih( adlqlJalY or till IHllipitullb ll(Ollllllentillllll11Sl bl baset] on the plctisioll of tllP final I(snlts oiJtairwd with the methods The )redpittlllts s(1e((( n HpJ (xtcllsi( (xp(IimPlltatioll all HatiH~ factor (Hee fig Hi 111lt1 tabItmiddot (jH) Ext(IIin tllts llllTild Ollt hanmiddot shown that H Hatil-gtflltlOIy [gtIpeipitallt 101 1lIbblI is (li-p(IT(middotnt HzHO (c p reagent nil POll sp gl U-lmiddotJ) ill li-P(l(Put (tinmol by vohmlP liol (tllayul( Ipl-gtinl 1l)-P~ITImiddotllt H)~o ill Hl) by ollln( ii lL satishyfaeto7-y l)lp(ipitunt A solution of 1 palt of H~~o to 1 part of H~() (1-1) iI2So1 nnd abo yarious int(lIlIPdiat( proportions of tlllse suhshystanCPs giyp fait 1(511It8 but with till inlIptl(l ill [h(gt ratio of H~S01
~
bull
bull
bull
bull
bull
RAPID PHOTQlIEfRIC DETEMIlXATIOX OF HtBJER AXD RESIXS 21
to H 20 the )olutioll becollles somewhat vbcou5 and precautioll Il1Ult be taken to ttvoid bubble formation When it i5 poured into tilt Cllvettes
It should be lloted that both of these precipitants have an ftellleshymmiddottion It was found that when XHjOH was used in the rubber preshycipitant in pInt of H~~O~ the readings were -table l)Ut were not reshyproJutihk The lIl of XuOH in pInel of H 2SO j ran nHittble result as a llth H(HY(Pl WIWll til( li-P(l put lthatgtl in lublltl llnalysis or H~O illlP-ius anal)j wn-i uddint(1 thl eharalteliti(s of till liquid with pleeipitated ruhber or resiu in HI~P(ll-ioll n ren1 on the lpNmiddottroshyphotometel m tololinlPtprfollop(1 it lPgnlal lIlll II~ lxplaiHd on pHgP-I (Sl( figs 11 aIlIIl) Tid made it lloible to outain lEPJOshydlHibll tpnlt nntI (onplt1J1(Jttly till JpqnitPIl tlPgJPP of PJPcljoll
IIWIE(TI 1lt COl~101J)
Jtl thp ItJiPl middotxlwlillltnb hefoJ thtmiddot -1l]YIlIt allll pnmiddotdpitallb had lIptll ptoppJly adjutp(l it l fOllll tIuH till llP or a Ploltiw colloid -wll ltIi1)cJ [ttlJmiddotntl- imlIopl tll lmiddotpro]lIibility of the lPlllt JmUkllly ()Ilt 111 U lput lUlU illlihumiddot tOJllPOlUtl tpHd liglyeol teltlut( - llpanlItly IllmiddotlfP(] to lit til I1m t IHflll lImnnmiddott nftlr tlH filial prOIptlllll WtlP dlvPllill1 tlll 11lIlpfit (If thtmiddot [llltlltin lollohl wa Hot 0 natlv I1l(lhmiddotd III rlumiddot Ia- of tmiddot ill tllmiddottJmillaritlu it b [1 hmiddotjlmiddot til IIpoundgt Ir llH1 It liltr ill-llImiddottiT Ina lll ptlPII by it U( in ruhhfl mmly j 11If dtmiddottail fOJ tltt lllllmtlllll If thl plot pet in nlloid ~llntill tltlmiddotlImiddotmiddotlttlatiflll lIOlllllllhtiPI1 are iPllllll page
liTFHFEHliG COIOf
(hi II tht lllail 11111111111 that had til ill -111111 II urklll) om tlH method fot lublJtt tlIlO1 rpir- nlalv~i in plaut llllpll- wa ttl (lilll~ inare tIte (gt1[01 till to tIll ptP-PlHt f xi [aIWIIII- 111 TIlt amount of (olor varip from lUllIt tn -amp ]pplwHlI nlt rhmiddot lt IIf thE Hl(ltllial tllP part of till plllIt -lI11lhmiddot(l tilt hi-tlllY f tlll plaut mtteshyrial ~ub-lltInent to Itlllmiddotnmiddot-rill lliI 1011middotly OrllPI Inlw
In ruhlwr lrtl-i I Iii 1101 au Itmiddot 1Iplll11l by 111[ I--r ratmiddottilt thE -lllll]t with uptoIw or 1middotmiddotlIll-ol - wIdell [llllol- rlll loillriu nutttel autI thtmiddot lpill- Thi- howmiddotvt n(tnll- til lXtla -11gt1 ilt prlJ~edun) In lP-ill ltluay-i nllHufldy tlW[t j 11 1 1IO(PIlln fill the 11shylImya of hlulophyll Hwl rIlI-r middotIOII IHlttlmiddotJ dlH lUtl~ In plltIH withoUt alo aiftIriL till nmiddot ulttrll
111 pllIbIll1l Wi tilmiddotr hId h It-ImiddottHI tht Pltlpll 1 hlitlt lilt tlw tulllWlli tollImiddot uIwltllIIntut -lltUIhorlllllltll 1111 tIll tlettlllliIttwr IIf t 111 lWlrl-Uamiddot of bdt tl11blLlittUhmiddot r [1 tItmiddot preshyj
lipitatifll 1lJ llllllWI atbull 1iI- in III -1nrmiddottIi fHlttalldh nlrillU~ amount rf middotlorilig lIUlttll Iii lhll of ih lltmiddottllllhottohttt~l l~ol()r infrtl Hm II upd 1 rwmiddot tld~middottilmiddottll PlllItlhi~ f it j proYitiltl with tIll lilP--UlY tU(jlIdlllIlml tIltmiddotmiddot lllklllUIlI
EIECTIol OF 1 [EGTH~
-Ptfmiddott ral tracilull ru~lI gtIll fr 1 nllb t ~xtltd 1 lIlt-th vI iobmy1 ketommiddot lWtl rill [ Ixt lttltt ll UttollylaIiIitt1l11I1t~ ~-I itoiu YtHil)u~ typp of ~IHaylllt f i lItmiddot art hraquoil ill fio1ll1 ~l Th~ lp-nlt fill I11oohl uio[1t ttl willlr til tltN- fur rht IUiXtIUt iwliutll
100
22 TECHNICAL BULLErIN 920 U S DEP1
90 bull eo
I shyz 70LLI 0 a LLI a 60
LLI 0 50 z
a ENTIRE 2-MONTH-OLD PLANTS~ 40 b ROOTS AND BRANCHES OF ~ 3-TO 4-YEAR-OLD PLANTSen z WITH LEAVES REMOVED ex 30 a C CURRENT-SEASON GROWTH OF l- )-TO 4-YEAR-OLD PLANTS
20 WITH LEAVES REMOVED
d LEAVES FROM 3-TO 4-VEAR-OLD PLANTS
10 A
0
a Cd 100
b bull
10
80
I-Z 70LLI 0 a LLI 60a
LLI 0 50 z ex I shy 40 ~ en z ltI 30 a I shy
20
10 B
o~__~__~__~~--~--~--~--~----~--~--~ bull350 400 450 500 550 600 650 700 750 BOO 850
WAVE LENGTH lM~)
FJGcm O-Sll((middotlllll tramaniW1IHl (mrpS f(JI (xlmll 11011 n J1ll of jlta)nle tissur ill n 2--m1 Y011111P of (A) Illrthyl ji1I1J1ltsl krtonp 1111(1 (ll) nt(middottQnyla(umiddot tClIc-C(l1osuln a-i
bull
bull
bull
RAPID PHOTOlIElRIC DETEH-UXATroX OF ntBHEIl AXD HEstxs 23
ThE dula Pl(S(l1t(lltl indi(ntp Ihut 101 Illp ulimls llHthyl liohutyl htOlIl (lxtrHts (lI(I r(dolls of Il1Hxi11111III nigtol]gttioll wiH1I all (is-lIb 11 cOllsic1(]((l n1( blhn(11 wn ( ItIl( Its lIO to () I1It~ nlid Ii to Iii mJL
WhllNIS tlw I(gions of 1middottnL(s( light 1lnlllittamp al(l lgtPlW(PIl wan Ipllgtltsnr) to Ii nllt jW) 1I1JL nlld alio Silllill1l 111l1b (n SI(lIlId 101 nc(ton ]altmiddot(fmiddotollp-(llloolp ~ pxt Ill of 11a 1111 t illl TIl( (1101 du( to lolo ill tlw litlltitl a 1Il1 lullll(I tH lPill- hanmiddot bpllI PI(_ ipitated ma he 1((I1((d to fltI ynbhing poillt II ph( illg OJ illshylmiddotJall(( WIWp balld nhm ()) IIIJ1bullbull[1I111 lxjlPIitllll1b Illln -h()1 that Ih( lIIot uilahl( WHYI lHlIJ fOI 1-1 ill 1l11J1l(I HIH11Pill- illllllrsi i-in till IlPighl)()lllll()(l of ~llIl1lt bull
bull UIlIilHlIy of n typhn] lXPllillllllt to )10 l1iP(tiP ((JIlllo( of (ItOIS dul to lOIOl in 1llblnI Hnd Iill xtnumiddott 11(11 IIIIolp t jUl i p1llelll((l ill tub]lL Till llhlllt- 1tpIO]II Hnd ((llll~()h whit-h UI(I ](]Hllilltl n 1I01lllIhb1 01(111 lxt 11111 IIll 1llll)1 nmtp[in I and )(middotills Tid IIlnkl it poiblp nftlI tlIp uplll1tillll or tlll o1PIl( (0 [niH lip 1Iidl1p~ of lI111 11111(( ill lit ll11l1)[1 (llnlIb nlld Ihll
Sl(ll n ol1lliOI with tllP olnl IJllt illiollt HIl Iltlllll llllI (Ill ltllthpl prpipitnnt j Ihll1 nddld OUI ha a lIilPt lP( of till lIiciPlw of WH( lllIgth 7) lUI- ill llilllillatiu (nnl till tll Ixtll1I101l ()lll~
Tuu tmiddot-Elilll IJl flrldillY 11-1111 lrlllI IjfJI til islII 1 1(1 ([rllt IIIIIJIlIr JiIlIt~ if 1Il( Ihll 111111 k til I III Ilrln I 1Intd tf 11111 JiSf fill I I II I tIII Ilf Iilltl 1f1JlIIillII1f I Till 1[ 1 IId 1 (I (middotIt 11111 (I1I1iI1 1lf1IWtlfJlIIllfflr p middottrllhIJ11 II J III 7IImiddotIa 111 111 lilt jJIp 111 wilTII
t~t tnVIli~ ~nn r kn t~ i tmiddot ~~l Jr 1middotmt ltlTt
HmiddotOtt ~I~ lin t I ~ 1 t~~l ~qrmiddotthtmiddotrtwb
Hult-middottltlru t T Hw ullut rHtt~ r II I ~ PH~lllt
A~tmiddottHHjmiddott~rjd rl ~gtllh 1 tn~th~ ~ ~ middotI lt~ b w bull hmiddotth~ 1i~lIhun 1 Ii tnl Illd1 -11lt1(11i lullI lUI tJl ll~ t1~11n( I Ihan1li flfttIJir Ult I Uuhtltt ahuul l(hmiddottHmiddot~t trv r fti HIt lftbyl tlonhUt)1 k_hIl( 2 m~ fmiddotf tuhlHmiddotr In mlth~ llmiddotlf- 1 t r
t r_~ t j
Arhlitlltd ~llIIDHl NcWitn1 ( Ar-(lt()nc~middotttrrtrt ritJJI~ -Iu nllJtl4-middotr
ACtmiddottflnp fmiddotxtrn( ~ T-P511ftf tn mtmiddotth~ 1 ~difmiddotut~ kdn 2 nltt ulruhhtr in Un-tIl lltbu )J~IYt
rUth(Hl~hltlft HhubU
Illlh(I(t tttUtUt hUbtl til J ~jlitl(J Hilllll trtIIImiddotjtl1ll
(UShl I ~tlO wHllolH rulh r (middot1111$0]( J~rru t t )lthyl 15bullbull1middot1101 klll1l
Ili( UHUicbcul ~((i1rUtl ~ulu1iin 1middot lIUIll Ilti lrllltlllt I Ruhhr llt1thuI r1 -1 Irld
ltlt1111Sh 2 nuz f)rruhl~rm nlith~l tu- h f nt nil~middothgt(H] tlrlftmiddot 9lUtirtl middot1 1
rlcltfl( H(l dnllltml it
(IISllhH~rI( Iultruhtr CII05 1v ltTlft I 2 UI~r ublwr In llldh I hlt~1 11) lgtjdvr(llsl~9rlltmiddot middotlmin ~ I~ gt AIHItilltl no IrttipHallr iI
~ Bbnk 10ol m(thyl i~tmiddotut~i kdHn H 1 m1 j~~ l1rH-t lt~tlfltmiddotn sf n it ll HltlMjftr~nol O2~mlJ ~U~1o-ulp ti~tW -xtra~middotl(lt1 ltt 411 ml bull ie f Ct- kft rt t~ tirattJ middott ill r u l1kn ttJt
in metltl isobutyl kNqnf nn~i mljp ur tmiddotmiddot ~oml ~urr tttl i t w ltJj1JH kt 4t 3 nlank 1 mL((l1t~rthmiddot(middot mI mttr~ ~but a kmiddot tmiddotc d 11 ~ gtli~b~ hifIAft- fl~ lL lnti 149
ml8(dlfilll BO bull 02 gm guayule U$Stl(middot xUlClt-l tf(h tft wI n nmiddotmiddotmiddotlgt 1 lznt on tmiddot ~Jt r~1 ~~u~~ H~ iI~ thT
24 l$CHNlQAL BULLETlN l20l S DJltJPT OF AGHl(CLlOHJltJ
In table a is pl(sentc(l such c1il((t edlt1tIHC showing that thc (0101 Ixtrnetccl from guaYIIle tisslIe wit h II(P(OIl( n nd (pl1oso[yc is cll(div(ly sCIe(nec1 out by the s(lp(tion or wnw length )0 miL Oil t1w SI)((IOshyphotonwtpl This tnb]p all-HI ihos thai thl Juhlwl altl(l((1 (nn IJl quall shytitntivcly 1(I(()(Ipltl in tIlt PI(ilIH( or Ih (o]OIplnwPIials and Illsins and tlmt Iuhb(l WtlS nppnlllltly 1I0t (xtltI(((1 110111 11l glll1I1l lisslIt b~ tlHSP SOhlllts Thls( ((suIts ginmiddot (OliIHillg (idJt(( that t Iw IISI of waYl llngth i)ll 1Il) OIl till SppdTophot OIllltPI ii t hl 1101(1 p(oshy(ellule in photolllliTie IlIlalysis of luhhlI OJ l(sin-
SELEGTIO- OF )IOiOCUHO)IAIIC ItIIm ((1111110
On th( basis of th( IPHIlb shoWIl in tabl(l 1 al hlllpls (1( IIln(lp to SPCtl lC the PIO]Wl 11101lO(lIOl1ln til Ii ltlJ ((lIllIJi nIl ions 10 llIiOlS (oIOlimet(Is 111(gt 7W-Ill~ filtpl flllnhwd 101 til( I1~lI1l photoshyplpct1i( (o]oriJl1ltll fol which Ill( (hlll(IlIiitit~ oj t hl Ilda he light ilUIlBlIIhiSioll (t) elll nn -hO11 ill fig1lle 10 iws satlsfa(lolY IPshysultl 111( iiO-mL HitlI olllhintioll 101 whkh ttp (middotIatinmiddot light tlnnsmission (ullmiddotis a 1-0 showlI ill figllll (I is -nthdnlto1 hut this is not stnlHlnld NtllipmPlli
Up to fhl PlPHllt lIS(middotflll pound11((1 (ulllbinntions jn lltl iOO-I11L Iunge hayc nol bllll SlClIlld 101 lhp Klpt 1-1I1l1I11PISOIl (olOlinwtll bu fnltlwl nttCl1lpti 1( )(illg IlIHd
TJIpound OF ST~lmW AFTEH HIIJ1EII Oil HHSIS rlll~CIIITTI(J
~ considl1ltiol1 of ttp lillll of Inlllling af((1 plpeipital ion of 111gt)(1
01 l(sinSTlOIll ollltionis impoltant J(jl~ thC1HI(Plltngp of light IInIlSshy
11 rshy10 f shy
09 f shy ~750 Mil- DOMINANTI
~ 08 cshy I WAVE LENGTH z
I III III i O7 - I III
~06 - 05 shyw
a
Igti= 04 - 720 Mp DOMINANT ct WAVE LENGTH- ~ 03shy
02 f shy
01 t shy 1)O~~~gt~- J 600 700 800 900
WAVE LENGTH (Mp
bull
bull
bullFIGlRt IO- COJllPIUlItiw ~IW(middottltll tlnIlRlllii-lion (II (IllP( 101 1i11(1 olllhinulloll
with dominllnl Il(lllllgths at 720 and 7iO lUi
bull
bull
bull
HAPlD PHQTQlfE1IUC JjETER~lINATION OF Rnmrm AND HEtiINi 25
mitted (spertrophotoll1eleL lCuding-) Ol light (1 (tClcrl (phOlOshyJluol01l1et(L lcndillg~) i~ StlhjNl to (hangl
]fjt~l1le 11 and l~ show that ill til( (asc ot tJaugtIllitteltllight llJHC th~ (x[llliHlllIlnl (oIHlitiOllS tllpl j lilst n dtlln-e ill Pll~(lltngl or UllllslllittnlH( follrnY(l by It ptJiml of lClntin stability with only sliuht (1111 tHn- a f(Pl a lIt1ll1btJ of minutes The light t UIllllitblllll t l(1 ill(Iln~(s This lIIay IJP llllllJltlli7P(ll1 ffl II ow 1Ilt )( f(( darI oliIII tIIlIlNlIlitt(IIIlfJIIlh (iditilIiid Ilil1 pllIipintnl )uoshyIn Of ( 8inx in (~f1( I~iUII i~ Ild stahl I 11 itlll If 1inl nh prlshyilli(ioll of 11l1d(1 II IJIX f) jllIli II (fJJltfiIIlilty slllMI IIriot 1) IIIPldUnl1i tll(I1I rllltltilJl oj tJi~ Jlt jiot IUN ilUf Jxl1 will tIt( tOWI IItlllilil I 1llIlllblJIol I ill I~11l11111 d ill till ifjuids JjOI scnttplltl light 011 till phololltHJIOIl1lttl till dilPCt ion 01 elangl b tlw IPrfIi (If that illrli(atPll rOl tlulll1Jittp(lliuht It Itlll b( llluliJr I-(Pll that if l(middotndlnJ- IIIP mad n itl I t lIP ~()ll1d()lb lpalll this pllioJ of nmiddotlatirp tuigtility tllP llLot tIOllt thi Olll(P (nil bl IPdUCld to tIl lltini III 11 Ill TIll l~adiltg (illH~ bbll Oil tlHl datn rUl lublwls and llsinlt Illl ginll ill tnhh
50 r----------------------------------------------- f shyZ
~ 40 ~----~W~A~V~E~LE~N~G~T~H~7~5~0~M~P~~~~ ~ --------------------=-=-= ~ 30 f- WAVE LENGTH 540 M~ _z _____ ___ -=- __ _ ~ ------shyt ~_=---=-=--I GUAYULEIII 20 -Z HEVEA ltt II KOK-SAGHYZ f shy
4 6 8 10 12 14 (6 18 20 22 24 26 28 30 STANDING TIME (MINUTES)
FIlirtn 11 Emmiddot of wav hll~rh Il li~ltr tlall~lIIit1alHl aftI IUIlItHt -Imlli lug 111m for guaynh llmiddotn 011111 middotiolIlJh~z 1111111 llijlitul1 flolll 1lHlh~ll1Jllryl k11II11l ~(lilltlll h~ lwitlitll 111Inu1 111l~1It1 2)1111 o1U11111 (Helillins on (illllun tlunhll IlIIJlllw]ntllW111 lutl(I[lholtllllltlt with ijUjt Wlnl IHI Ilf1 I
11 EFFEGT OF Hbli 1 -()JXT10~
Tilt lnblwl ~()h(llh pxtnl( till IPillgt ubo It 1m nllu1- bellt -~atea thut ~lll 11-111- tUP olnbhmiddot ill middottIIlIlOl ~1It tlWIIJI( my U)t PIl (tlIHatcl WIth tl1l lullh(t I tahle lJ 1hln 1- -1111 tIll (llllstlOll of nny p()~iblt tITptt of XtIIl11 diflp]lws ill ((JlllPllttUliollS of 1l-in lil lolutioll alollJ with till 1lIltbpl TIU data ill wbh +ho on tIl( hn~is of (olorilllPill ladillU thaI tll( IIUOIl1t of lnbbll Plllipirntld 110111 Ilwthyl olnlld kptOlll olntioll IJ 1li-jHlllnt 1l)04 in 1-llltlIllt ethallol)- not amlll hy thl llllNlI(l of llvin aU1ouut of llins inolution bull
-----
26 rECHNICAL BULLEfiN 920 U S DEPl OF AGRICULlUHE
100
90
80(I) C)
z Ci 70 UI a 0 60 a ~ UI ~ 500 ~ 0 I Il 40
30
A 20
0
100
90
(I) 80 C)
z Ci 70 UI a 0
60a ~ UI E 0 50 ~ 0 I Il
4-0
30
B 20
0
--
--shy ---shy---
2 4 6 6 10 12 14 16
---shy= ~ ~ shy
-
2
025 05
10
15
20
25 -30
35 40
SO
-60
=70 80
16 20 2224 26 26 30
OS
- 10
IS
20
2S
30
35 40
-50
-60 -70 -80
bull MGPE 25-ML
VOLUME
bull
MGPER 25-ML VOLUME
Florm 12-EtTld (If till1l or Slllldill~ 011 light transmittallce (01 (A) gUllyulc lnUIl(I plccipitllitd frOIll llltt h~l isobutyl Ielollt solution Ily neidilic(l ethanul bull null (B) gUllyule ll~illii pre(ipitated flom aeltoll~lllcetOlll-Cl])osolY( 3-7 solushy11011 by H(illilip(i l1U (HPlldillg~ nt -lIlillult Ifllpluls 011 Evelyn photoelectric colorimellr with jU-lllp tlllll alit U-1I11 npN(lle spp also table 2)
bull
bull
RAPID PI-IOlOMEllUC DElEnMINAlION OF RUBBER AND RESINS 27
TADIbullbull ] 4-ReZation of amiddotmount of middottbber pleeipitate(Z Oln metltlIL isobutyl ketone 80lutions by OS-pereent H 2SO in 95-pere(lIIt ethanol to umollnt of resin8 udde(l U8 indivute(Z by colorimetrio readinU8
(Rubber ami resins cnlculntcd on bnsis of amounts in 5middotml ullquuts of extract from 02 gm of tissue in a 2fllll olumo( bull
Hubucl r~cocrell whcll rcsins nddcd as IndIcated Htbbor al1dcd (pllcollt) ---shy
__________bull_________ ~_12rpcrc~15011crccllt 7511crccnt IOOpcrcent
PerCtllt ercellt Percellt Percellt Percent o o o o o) 50 250 263 252 25000 500 500 500 500 700 750 750 751 749
1200 1250 1250 1250 1250
EXTRACTION TEMPEHATURE AND TIME
Typical experiments to detllmine the time required to secure maxishymum extmction of rubber und ltsills at 115deg U Ilre sUlIlmarized in figule 13 the solvents used-methyl isobutyl ketone for rubber anrl Ilcetonylacetone-cellosolve 3-7 for resins extraction-are very eflicicnt since under the conditions indicttted maximum values were secured after 30 minutes of ext1llction The most eflicient liquid for the bath (lig 1) used in extrtlcting rubber or resins is ~ high-grade cylinder oil (S A E ~O) The sand bath and such liquids as glycerol have proved unsatisfactory
RUBBER AND RESINS STANDARDS
According to the National BULeau of Standards 1-_ lhclc Is no gellcrnlly recoglllz(d standard lIIutcrlul [ior II rubber standard] The rubber hydroCllrbon ill llifferent samples of conmlcrciul smoked sheet or pale crepe from heclI pluntlltions nries from l~ 10 04 llercent of the totul nutletmiddot the most 11Ioruble conditions Of preparation
McPherson () has described a procedure for the pLeparation of pure heve~ (Hevea brasiliensis (H B K) MueH Arg) rubber from crude rubber or latex In the absence howevcr of ~ generally recogshyn12ed stalldard for rubber hydlQcllrbon [caoutchouc (CnHUs) xJ the standard adopted was that of the relnthely pure product secured from gunyule tissue txtractiotl nccording to the Spence-CaldweU method (5) or the motlified PIOCCdUlU of Hohnes lind Haasis (p 2) The details for constructing the calibration CULes are given on page 10 Standard rubber samples apparenl-]y can be stored for a long timc under the conditions des(libed on page 10 The duplicate colorimetric lendings for glULyule rubber newly extracted by the modified SpenceshyCaldwell method were ()J2 ench as compared with US) each for the sample extracted by the same method but stored 1 years In each case colorimeter rcadinllS were made on mixtures containing 2 mg of rubber in It 25-1111 Yolume
The selection of tt suitable standurd for guayule resins presents some dilliculties Tll(~ acetone extract of gUllyult estimated on (l gravishymetric busis~ for instance proved to be variable depending on the type of tissue sampled or season of sumpling because such fractions as
COllllllunlcntion dul(lt1 Octohtr 22 11H3
28 QECHNICAL BULLEQIN 920 U S DEPT OF AGRICTTIIlURE
16~==========================115 shy
14 bulli= 13 z ~ 12
ffi II Q
10 c w 9a w
8gto () 7w a
6a w
5en III ) 4 a
3
2
A 00 5 10 20 30 60 90
14~------------------------------------------- bull13
i= 12 z w II ()
a 10 w Q
9 c w 8 a w 7gt o () 6 w a 5 If)
z 4 If)
w 3 a
2
o+B~~__~__~____________~__________~ 5 10 20 30 60 90
HEATING TIME (111 NUTES)
lllGUltE 13-lDffect of time o( lICntillg O2-gm samples of gunynle tissue with solYlIt nt llfio C on lo(OVl)ry of lllhlJer alld 1Isim Lt HlIhblL extracted with methyl isohntyllwtone B resins Cxtll1cted with aCftonyla(etonc-cellosolve 3-7 bull
chlorophyll are weighed along with the resins in the acetone extruct but are not estimated by the present photometric method (fig 0) 1he use of a diffeJent stanclttrd waS therefore indicated
bull
bull
bull
RAPID PHOTOMETRIC DETERMINATION OF HUBBIm AND HESINS 29
The resins standard selected is based on n relatively pure source of resins the rcsinous exudnte 011 the stems of guuyule plants IJldimishynary expeliments with the resi nouS cxuclate from diffcrellt gllayu Ie strains of various ages indicatc nHlt there is little YaLiation in this subshystance on the basis of Colorimct(r readings 011 2-mg aliqllots of 01shypercent solution in It 2i-ml volume (tabl( li) Expelilll(lnts have shown that the air-dried (xuclate contains 3RtOH p(Ic(nt of -volatile matter This material is l(latiyt~ly stablp ill (OlllpoBition and is npshypurpntly on ly slight ly hygroBcopic as shoWIl ill Ia bl(1 1 Tlrp Ipsinolls exudate may be jJleplpd in two wayi-i fl liSP as a stallClHld-(l) the clpan exudate is clripd iol Ghouls at ()1deg C at W indlPs of a(lIum Hnd aftclbCinOglOund ill a molfalis 1)I(spI((I intn airtight COllilinel OL
(2) tllP Cx7lclate is clissolllt1 ill a(lhllll and filtplpd PlactieaJlyall of the acetm1l is thpn lYapolntwl olt OPI a stlam or atCt hath and Ow residue is dripd ground an(( PI(sPIld as ill tllp fin lllethocl Tlwse two prepalHtlolls a1( (ompalpd in ta hlp ) 111( (((tails fOl ~t()lil1g the resins standald and (onstlllcting the calibration CUITPS alc given Oil page ]2
lAIIIg fi-CUIIIllrsoi (lJ lIr-dr(1I IIIIi 1((11 II II-()I-tr((l l(sil~ 11111111(8 of I II 1111Ie
[Colorimetric rrndill~s 011 1~I11 phulll(Iclrie eolorillJct[lr with i~()middotmll (100- to iiOIIIIl) fillcr [lnd 5-1111 lIperture preeipitantl part ofO5middotPIrctllt 10 to 5 paris of IIOj
nupliclllc(oloritwt([
nIl(lin~s (hIlSlcAg~ ofSlmillXo JrNliltlCllt of fPsiJI$ L1Xtlrlntp on 2 IIIg ofplanls fllsins (XIHIIlt~Jwr 25-1111 vol
tII1(1) 1
leflTs Various _ bull ____ bullbullbullbull 3-9 Colll)Josiltrlairmiddotltlricfl bullbullbull nf)2 002
])0____ bullbullbull _bull __ _ bullbull ~-l Composilld (ri d at n5 C in aUmiddotimh lWUUllJ for l (jOuj(ja hours])0______ bullbullbull __ bull ___ bull 3-0 COJIlpositld disso]NI in neptolll f1l1erNl fl(lf()ll( GGO i(jO (Ivaporntld olT OV(1r Stpl1l11 halh TesidlH drl(ld I1t fi5deg ( ill anmiddotinch VIl(Unlll for 0 houlS bull
middot106 __ bullbull _ Jir~c1rild_~_~_ _~_ ~_~ _ ~ ____ _ __ _ OUu GOifina_~ ~ _ ~~_~ ___ _ _fln~ ~~ ~ ___ ~ __ 6(imiddotI tiliA H)[_ ltlu bullbull i18 tisSflOabullbullbullbull__ bullbullbullbullbullbullbullbull lt10bullbullbull _ tillO llitO406__ bullbull __ bullbull __ bull __ __ lt10_ Utl2 fon591_ fo__ bull liGa oOa 406bullbull _ __ lt10bullbullbull_ li5S OM
j Ph( vnluls in Uw Inst COIUIIlIl indieatp thnt gunyulp fesinous (IIHlnt( wlwtlwr dfircl hi Yn(tlLJ1l1 wilh L~ perc(nt loss of volntllt wutl pr or tWl c1rild giVPd npproxil1lnh1ly t Iw snllw colorinwtCr rNHiing- 011 till busis of aliquot~ cOlllniuiug 2 IJI~ of flsillS lXIHlntp l)tIf 25-mI volultl( Ihil- illdicate~ thl11 Uw UITW IJ1flS~ of olnshytile mntl(f prt~(iJlitnt(d gins npproxilllntlly Uw $1II1l (oiOfirnl1tlf ftudiTlJs ns tho ftsidtw A pnlill1jllaf~middot (XIlltrinllnt indicutls thlli th VUllltill muller l(lIlSists of thl Ilrplne oil fmcl ion I5-(1Il gtnplls or rlsitlOtlS (lxudntll gnvll by stPll1U distillation nn Uefllgl of 011111 of jl(lfPlIW oil with npproximHte tilllsity (If OHIi lind lhus rrprlsll1ll( IlPIJroximllt(I~ 01 Jerccllt Of t he original weight 1hls lllrClnlage complrcs wllh 38 llltrC(ntlost by drvinI( in IICllnllJ
aSplusmnUH perceilt or orlginlll weightlosl
The wailnble illfolJllntioll on tlH (ow-JitlPllts of the gunYllle r(~shyillOllS exudate alld tl1( HeetOlIP ext act of gaylp ti~slw is sllIllmarized in this paragraph lYalttI (u) alld also Hangcn-Slllit lind his coworkshyers 16 reported that 20 percent of the resinolls exudate from gUltyulc stems is parthenyl cinnamaie (CHuOH=CHC020 11JI2r) Steam disshy
15 (OIlIJIIIIUicatioll flom A T Haai(II~l11it llId (0011(11 Calif0111 ill Tnfiitnte of Tccllllology Past(IlIJI Jhps( wOlken al Htud~ing the COTlHlitlllllts of the acetone extract and other conlltituellis of guuyule
30 TECHNICAL BULLETIN 920 U S DEPT OF AGRICULTURE
tillation of similar resinous exudate in the writers laborntory has yielded approximately 4 percent of the whole as the telmiddotpene oir fracshytion Haagen-Smit and his eoorktrs nportec1 thttt about 25 percent of the acetone extract from guayule branches is parthenyl cinnamate and 6 percent of the bark (ltortpamp-phlotm) extraet is parthenyl cinshynamate These workers fm-thcI reported that 25 lwletnt of the nc(shytone extract frolll bLllllches is a compound with the tlI1pilicaL formula CBoH400a 1 percent is a compound llwltillg at 2P to 2T5deg C and 1 percent of the extract from the ]eav(s is tl (olllpoulld nwlting at 100
to 1710 1Valtei (6) reported that 3 to -l perc(nt of the tI(eton( txtract
of leaves and flowering StPIllS of guayulc eonsists of waxlike substances soluble in olgallic soln~nts but insoluble in at(l and (on(ent1llted H 2S04 The flactions mentioned on the basis of (onHLTutle esti shymates of amoullts actually isolated tlecoullted for about H ptIcent of the totalncetollt~ so]ubles extracttd from tll( guuYllle 11 rub The other constituents ltlilaill to be i(](ntifi(d
RUBBER AND RESINS CALIBHATION CVHES
Typical culibndioll Clllves iol Iuhbpl and I(sins bas(d 011 (ldtLminttshytions made nccoLdillg to the plocCdmC outlin(d 011 pages middotb to 1G arc shown in figulPS 5 and 1+ The spCdlopliotoll1lttL en (OIOIjlllctCI readings are plottCd on s(lIlilogalitllllliC pappi ag-ail1st (Il 11IbblI (011shy
100 ~ 90
80 ~ 70 ~
z 1amp1 0 II 1amp1 IL
1amp1 0 Z
60
50
40 ~ltI 30 ~ en z ~ ltI II ~ 20 C) ~ oJ
10 o 2 3 4 5 6 7 8 9 10
RU8BER IN 25-ML VOLUME (MG)
bull
bull
bull FI(lURE 14--Ctlihration curve fotmiddot gllftYlIlc lubb01 (Hct(lings Oil COIPIIHlII tlOl1hl(
monochromator SlCClrophotolllet(r with 7fiO-11IL Illtel alld Hllp Wll ( IHlll()
bull
bull
bull
RAPID PHOTOMETRIC DETE~MINATION OF RUBBER AND RESINS 3]
centrations From a casual inspection of these CUlTes it would appeltr that Beers law does not hold Actual tests indicitted that Beers law was applicable only within a narrow range in the upper portion of the curves The analyticlil results on the basis of photornetric readings nre therefore calculated by direct reference to calibration curves or from reference tables of equivalent values bllscd on the cnlibllltion curves
Calibration curves for kok-saghyz alld heyea lI11tulltl rubbers and Buna S (GR-S Chem Gum IV Goodyear) and butyl (GR-I Standshyard Oil Co Protoc) sYJlthetic rubbers are hOWllil1 figure 15 The samples of kok-saghyz rubber were furnished by the Diyision of Rubshy
100
90 ~I) ()
z 0
1amp1 a
~ a
80
70
60
s 1amp1 ~ ~ 0 ~ KOj-SAGHYZ 0 l Il
50
HEVEA~ ~
40
100
90
~ 0 80z Q 70a Co)
a 60 ~ 0 0 x 50Il
40 ~----~~----~------~------~------~--~ o 2 3 4 5
RUBBER IN 25-ML VOLUME(MG)
FmUIlE 15-CaJiblation curves fOl kok-snghyz h(YCII Bunn S lind butyl rubb~ls (Readings on gy((yn photoelectric colorimeter with i20-lIIp filtpl and 6-ml aperture)
32 TECHNICAl BUIJLETIN [)20) 1 S DEP1 OF AGrnCUIlfURE
Iwt Plant JIl(I~t ignlioll of thi BlII(un and (1( l))(parcd according to 11( SPltI1((-Culd (]] (6) PIO(((lllll Hlpt pal( CLPPe was (xtmch(L with acetone blI()Ieit W 1I(gt(11l a ttnlldal(l
SEXSlllVllY Ol~ llETJIonS
By lip pIO((l(II11P olltlillP(l 011 ]Hlg( +n Iowa (lOOl IIIg (11 1111i(l0shygmm (gHlllllla) of 1hblI ill a 2)1111 yoltll1ll (all )(gt dltpltld Oil tltl Col(man (lohlP mOIlWhlOl1lHlOl l-I)((t 101 l1lOt 0111 ci( I ill1ilnlly 001 mg of Iublwr ill a 2J-1ll1 n]ulllP Illay bl Ilad Oil till EnI)1I photoshyllectlie (O]oLillllt(I Thll ya lllll- 011 tilt IHl-i- (J I (xl ad iOI1 fmlll 02 gill of til-lI tH(JI(lillg to tllP -lllndal(l jll()(pdull 1(PIPStlIt IlO()2J tlnd 002) P(IT(lIt of llIbl1ll IPI)(((inly bull1t1lollgh -lI1t low allils can be d((d(middot(1 il lIoullt1 Ill IPtllizpd thnt till PIIOl ill PlI(Plltng( or tll( al110unt dltlIllIilll(J i ltlatlpl high ill tili PIY lo Itlllgl 111 aetllllllladie(middot Ill( lopl lillliL 111)(1(1 lIw (ollllil ions of tlil ]lI()(lltlIIIl u ol1tlinpd ipt at l11 11I1 or 1111gt11(1 illt i-1ll1 Ollllll IlPIPltPlltillg 01 p(gtl(pnt of JllUiJtL un tlll 1Hli or (xlla ion rlOI11 II rlll of tisSIll
EIlIlOH COSIIlIHIIO
In Oldpl to H(IIp ill )1lHtPltt pl((iioll illlpIi1I- it i lH((SSHI to slnlldHIdiz(i rigidly 111( Pl()((dlll( 0 illdi(ntpd Oil pnglt- - to J( If lids i dOlH tlip lXIHlinwnlal PIIll is t(middotdllld 10 n ndninlllill
Illlt pl(iioll of (hI ]lIPPllt 1IHllwd Oil til basi of ]llllP llIllJt1 alld Ipsinssollltions call hI jlldgl(J 110111 figllll Hi lileh lio- til HPIlIgl d(intioll oft -illgIP lI1lnSIlIlIIIlnt in lHi((lltagl of Ill( alllOllllt 01 Illhshy1)() 01 lpsins d((PI1I1 iJlld TIl( (1101 PlI(Plltaglt H1( gi (1 101 OJ) to
RUBBER IN 25-ML VOLUMEMG) 004 01 02 03 04
i= I I IZCtOW
fbA ICtU CtCt WW a
01 02 03 04 05 06 07 08 09 100 = RUBBER (PERCENT)
RUBBER IN 25-ML VOLUME (MG) 10 20 30
~ I CtZ
bBOw Ctu CtCt Ww o I~
010 50 100 150 200 250 RUBBER (PERCENT)
RESINS IN 25-ML VOLUME(MG) 10__ __3-0_ 40 50 60 70 60 90 100--_-- 2_-0
Ct~ -r- 1 I OZ
WCt UCt b C wCtW
a o I I 150 250
RESINS (PERCENT) o 10 50 100 200
bllI 1tI W-Yllnl dtd1 ioll I I 11l1 11IlI11 1(111(11 1 III Plll- IlIIIlol1 01 IIim~
bull
bull
bull solution Il basis J o golH of tiSSII (JlILCl-nt (11(11) for (~I) (l)1 til O 1I1
of luhllpl lin 1 III I (I Ill of lUhlJPl nllll laquo I J to 111 nlg of IlSlllgt (Itllillgs on ]iYllyu pllolwh-llrk CO[IJlilll(-(PI with nOHIP Iiltlr lIntl U-lIll allcrture)
RAPID PHOTOlJElRIC DELEHlllNAllON Cn HUBBER AND H1~SINS 33
10 mg of rubber anel1 to 10 mg of resins in a gJ-m1 yolumC For
bull
bull
bull
comparative ptuposes the leslllts arc also calculated on the basis oJvershycentage rubber OL tltsills in 02 gllI of tissul As WOlllL be expcet(d the error increases sOIlHgthlf for 1(lali nmiddotly low COlHell t1llf iOlls oj rllbbeL or resins The curves in figure 1(j s1l0 that ill til(gt Illlge Ol to 10 pCrshyeent of lubber the elTOI rangts Jroll1 abollt Ll to II) ]IlC(lIt abo(~ this mlllc tIlt (ITOl d(((ts(s to (ollsidlItbly ltmiddotss (han 1 1lICPllt of tlH mllollnt ltl((Lmill(d Hil1lilally in tlH (lISl of l(sins analysis (fig 10) the ltLTor is (onsit1eIubly INS than 1 PlLllnt ill (he lallgp of 11 t~) ~() penPII t
In nil ([lSl of lllhblI alld (sins lx(Inltpd tIOIl1 (issups Ol addcltl to tisslle lxtlads (s(( tabhmiddots (i H) illyolillg ll01P o(lllntiolls the eLI01
is hig]wl thun that indilHtld in figllll ((j Im pUIl Ill )])p I tllllllsins solutlOII
COlllUCIIOXFOH IXSOLl-IlLl~ Ilgsqgt(Jg
111 th( Jllo(pdulP ollllillPd 011 paw I till illsolllhll isSII Ipidll( tflpl (xttlw(ioll is (Ptill tlw lIask l(lll till xtlct i l1wdp up to yoltlllH It is not rOllPllipnt (0 IPt()PI qWlIltitati(Ir III(lw[olH a 11(1 pllooll extlnlfs of guuyull I is-lll alll thl1l main t11l111 up (0 YOIUllllmiddot bpCaUHI sllch all additiollal stltp wottld]) tillll-C(JllS11ll1illg Th( Iogiea nll(gtIshynntin is to mnkp tltl lXtlUCt Llld Ipsidup lip to OllillH in till original flask andi llPSStllY 10 llwlno tl OIIpdioll wlHIl (allIlnting [hc llshy
Hults f(JI [hl oll111lC displupd hy till ins()lllbh llsidll( III it l)picat (IXpednHllt (ollsisting of Jhp lppJiea(iolls if was Iollnd llftt at ~iiO ( 02 gill 01 Iuhhll pillS IPill-fl(( lisslI(gt (lollpdll fot llwistUlC ou basis of dlyillp ut lOW 101 ) llOlll-j (lbp(ld only t~ llllUll voiul11P of OOk7D~- OO(lOO(i Ill of lllthyl bolnl(yl 1lIOll( (lplhlli(al-t(Tnltle sp gl () Ii I ll(Hli (j at ~)) -gtitllP tl1(gt 1It101111( () r t is-lIl xt Iadld j sl1lall til( PlIOI dul to Ill(gt insoll1blp Ip~idll is slllall III [0111 ill( wOtk it (all lJp diIpgal(ll(l
]hcon~lIY OF HllIllgl AiO HESIS AIH)gl) TO EXTlIACI OP
GlYlLE TISSlg
Tnl)ll G L(IHpslntillp (ypi(nl llld(~ SllOS (hat all a plngl of HIOK PlI((nt ot lltl pltl( Ilhl)(l acldpd to tllP Itll h iolJut1 InmiddottcJllP xhnet
of guayulp tiSI1( WllS 1l((PllIl Tlli nllintioll flOlll (olllplpU I((OYshy
PIY i within flll pxp(IiIlHuttllIIOI ~illli]llly fnbll Ii llows thn 1111 llYlIUgl of 1O(1~ ])(I(Pllt of gllllYllII 1(-i1l- add(d to II( (pllosol( (xshytrae of IUllY]l t i~HI Is 1l(oPIPI
THl~ (~ Hf (Off Ill of 1111)( J OJ I~il~ lItfI(( In ~(JI1IJk~ Ilf (111 [lI1Il fI2 lIII
0 tlUfllllit i~~I1
Instrument
---- ----~---- bull shy 1(1
Colemun ruono~ltrOUlllt()r 2t) II sJl~ctroJlhOL()lIIeter with 2tJ I iflllllI wnclength Fetting 21 II nntl 0-1111 WU HI hUJl(L _ L U
Ill 7Evolyn photo~lcclrie (olor JU [ imctcr with iO-llIl filler IV (I
H1 0 t I I
llImiddot lUn WII 1011 HIO Wn mil lUulon
10 JIg1111 IUI ml lUl anh Io aLn 111)_I ) III li lU It 2) deg wn2SU DD
Irl JIll II IIr II US II
1110(1 lULa lUI IlK) IJ WU
I( llI Htl tNI 1(111 2tlNI HI 0 221) lllil t2S 0 1~ 10 1~13
In (I 2117 I
10U 1l(J ~ 4 _H_j ___
9middotJIlJ5 10115 10 00 lUU5 flUU 4li (tl03 9(11)
leIlKl 1l~)5 lOOU l1KIr JOIS un 003 OIl Ii
34 lECHNlCAL BULLErIN 920 U S DEPT OF AGRICULlURE
COMPARISON OF PHOTOMETRIC A1D MODJIoIED SPENCE-CALDWfLL METHODS OF RUBBER ANALYSIS
Guayule samples were analyzed by the photQ111etIic method and by bull the modified Spenc(gt-Cnldwell mcthod The values in table 7 represhyselltativ(I of typical results indieate It -atisfactory dcglpe of conformshyjty between the two methods in thl range of tiSSlHH with llHHC than OJ) percent of rubbtImiddot On the bnsis of the amounts determimd the results in this runge for the plmiddotts(nt lIlcthod ayernge apploxinHltely j percent highcr
~LAIII~ 7-(oIllJl(i~on of lltlllrIic (IIri mOtllinl SJl(II(r-(ulri-wall IIIrtlwrl~ of rlrrlIIillillfl 11)1)(1 COIIrll of UI(III
1 Flowers frllm amiddotmonth-oltl nursery plants
YAIIIATJO- OF SIli(LE DETEnt1NATIONS Fnoll TnEIIllIEAN
Rllbbel (Uall8i8-Thc plcCision of thc pLcsent method when gunyule tissues Hr( nnnlyz((1 for rubber may be j udg(d flom I Ill datil presentcd in table H TIl(se dahl -how that thl pplCPlltag( uriation of single determinatiom from nwan yullles with low standllrd enolS ranges from less than 1 to 4 p(gtrlent
R(8in~ wWlsi-r-s lndi(a((1 011 page ~j he INntlts s((uled hy the present phoolllttric nsins llHt hod are not tliltly (olllpalable with those of the grtLVimetri( ncetol1l-cxtlt1(tioll II1etho(l Thjs made it necesSllry to selc(t another lalibllltion staudud-tlll Ipsinous exullate from gullyule shrub-thut gies relatively COllstlllt photometric readshyings (table 5) The resin (olltents of guayule roots branchcs or leavcs usually ran(~e from about) to 1-1middot pelcellt The ple(ision of the present methotf WhCll gUHyule thslllS lIe analyzed for reins may be judged from the datalHmiddotpscllted ill table 9 1h(se data show that the p(lcelltage variatiun of sillgle lhmiddott(Lminntions iLO11 meun ynlnes with low standard NTOrs rangcs from about 05 to 4 percent
bull
bull
bull
bull
bull
RAPID PHOTOMETHIC DElEruIINAlION OJ RUBBEH AND HESINS 35
IAIILE 8-luriation inclieute rubller (mallSM of [1wIIle tissue bll thc 1111O0Illclc metwII
Vnrlntlon~Ilbher I (rom mean
ierCtnl Percelll ~OU -22 ~ 25 +27 ~ 20 +18 ~UO -22---------1_______ 51110 0G6 bullbullbullbullbullbull _bullbull
10 ro ----=ii41075 -01 1000 +11 1010 +13
rlln HI itil 1l9~ 1_ ___ =-~~~
115511 ~ US -111 III II 1575 -13 115 b tiS -I a 111 h WlU +22IIM-(middot bull 11K -1Ja Illi c 1000 +03 1J5H1 W +l)7 ll1imiddot tl 1575 -13
Mcnn 15951 131
1102-11 21fJ() +21l102-h _ ~~)SO -17 1102-c bullbull 21CO +21n02middotd ~OIiO -26
2 r~plusmn Il~ 21151 261 I -~-------bull---__ _~~_~______l-___--_
1 lhe$ 1111($ I1n (or SlIlIIllltS Stpnnltplr PHrilClld IIrtlrdlng 10 1hr prollIlIlr( OIiIIiIl(o(I on Imgt$ 4 to IC ~tcond nUlI1 hlr r(J)[ltnts stl1ndnnl llrrot of tilt 1I1(1111
1_1l1~ n-J(lri(iot in relli(Upound rpoundsins (lllalIsfs of VIOJII( lixsue b1 the lhomillric lII(lloli
-- ---~--- - __-------- shybull I I I I Varlgttton
_________~___ ~~lu_n_Jl_Q_~~~_____ ______I__~_o~S_J frOID lDean
Percent Percentgt458-1 ~65 +41IWtl-li 130 -a2Hli8c aliO +26S41i8-d bull 130 -32
1(-011 34I10Olifgt __ bullbull __ ~--====
li-9~2n 881) -06 li-9~2-b Si5 o ~HH2middot(middot S i5 -6$-H2middotd 000 +1
8851 054
O i5 +6 9 i5 +6 950 -20 U75 +6
H-liG3o-n bull -1 n-li6~b bull __ _ -IH-IWH +4H-l61511 bull -1
1tmiddottlU
62~-lI __ 62~-b ij24-( bull OH-Ji
(-Ull
I rll(St oluls nre tor separately ~xlrflCled SllllllllCS IlctOrdlug lO procedure outllned ou pages 4 to 10 i Secoud number r~prtgeulS stulldMd error of lIe menn
36 TECHNICAL BULLETIN 920 t ~ DEPT OF A(]RICCLTCRE
ReUUER A~ALYSrS I~ CRCOE-RcuUER PROOCCTS
Sew rapid photometric m(lthod~fol the ddellllinttion of rubber and reii Hi ill uaYllp ti--ut htp lllell pIPHnl pd oil pag( ~l to In A brief H1111111tlY of It similar rnpid llHthod fm 1I1hb~rllnltlysis of u1lulcanizNl tlIldp lubbll pl(Hlmtlt whielt i~ bn-(tldo on the prill o
ciples dehtilcd tlllLe follows Duplltate nt-gm sllmph of the finely cliyiliNl IlInttlitiup wlirllll out [~ei-()l (all hl lIf((tinmiddotjv INd to lt1iyidl till alllpl) TIll kltolll-olubll portion of till )111(11( tlrc di-olved a- indh-Htpd fot thmiddot lllnkill~ of -tlllHlunlluhhll olutiou Oil Pt 1II hut tIl IUlIp Hn lIn l-fplImiddotd 10 lHI-ml rolllllltti( fln-k antil1ltld(lup to Olllll1l The bnlulUp or till JllO(ldllll i- thatutlilllll on paWs -1- 1 IHI Ii 111( 1(111 1- nIP IXPIP--pd nil til IHi or Iw oligiJla w(lullt of I Ill (I11l1p-I1l11Ilt1 1)(0(11(1
Hupitl PlllimiPJojgtiWllllllllh llIltllOd~ fOJ Ihl llPtlmiddotminntion of ImiddotUlJbll tlnd 1(-illo- ill -111111 Illllph of gutlYllll tiUl IIll dl-eli)ed 111() IlltlY d~o Ill nltlI1lld fOl III Iwl Illhlwl- and l~iJlmiddotb(lLiJlg plant TIllt l[Olllhup hns nlo b(l1l ntuptpl fot IIH lltlIll1illtltioll of lllhbpl ill 11lHhrublwl Pl(Jdlld~ HIIl 1111 hI ndaptld JoJ IIll ann lysis of ynt1J(gt( ic lllbbl[- The llllthmb HIP 1gtn(11 fill tIll fol1owill plimiph- III Grinding
tIll PIOPlly driPl t i~lIl 01 Ul tillg tIll pnHhHt to tll l((lllilllllh~lel of filWlH-- til plllllit qIHlIllilnth( lXIIHtioll 01 IIlbhlI 01 1(--IJl- () llsing oXWllutld olnuh (kttoJls IIt(talp and() fllltil for LIbbel and IH(ltIlIlyptIJllIllIoolYlnJld-o flJllh 101 niJlsl with t(lathelr high IlPililig points 111 to n C) l]olle or in mixt tIll thllt Pll mit tlll rnphllxututioll of luhll(l OJ [middot(ill ill ~() to (l mi1lutp It r(latiwly high 1lllIllllltlltP Ill to 1~11 ) l) lllllipitntillu till luhblI OL Imiddot(ill frolll aliquot () f till oltn ion I IlIlllI-i () f Hlltabhmiddot pl(~(i]litallt (willifhmiddotd lthmwl fOl IIlhlHI Hild llitlifild lllr fOJ JP-illl t~) IIlHkillphotollllliilPIIIIiIlof PlllPlltal of liht tLaIlS mittUl(P lIftlI IlIlbll (II Il in PIlipitalioll 11 II WI( Iplllh thnt (limiJlall till PIIOl dill 10 xtralllOlh (0101 (till dptl1minntinll Iph jill 011 tIll dtwlopllIlJIl of H HIli rOI1ll tlllbidity 111 hpl than I (olot rI
jJlIlpOP-ofallnlyi-I ( p(lllil1thb IIllijOI1ll turbidity or 1llt[lIinmiddotd d(ltl of jgtIp(ii(JlI l)~ lIltlkillU tIl plllltollllmiddottri( ntdillU al tandinu tiJlH~ (dlllilll wlli(h IhlllH(lill-- IP 1llutinmiddotly tnhll) t1ll1t an hlsl~1 oil the (oJlItlIlllItion of IIlhlHI Ill I(ill (lIPIipitat((L
TIll -I(p ill till jll()(Plhul HIP 1-- follOylt (1) 1l~UIIL uJ1lplls of thwl UJfJlllHl (II tliddl(l HUt dlipd 11Illtplial an lXIllltel with11 Ill of till nlnll ill t (oU tlllltIPlll[gtPImiddotatlup oil Iath at 11 Cbull fol 11 minutl I) iIP1lIin(middot(lohd til( (XUtllhllll Jltldl lip to It middotml ynlmlll til( (nlifild by (Illlifllgiuu HlId thlPl IlI nliql1ot of tIl (IalioPlllxUlltl nll Uillltlmiddotll(t to l-llll OIlIIlIllril fiuk- (1) For a trial Ilnditlg 0111 III tlll j liJmiddot~t IllHII IIjI to Ohlllll with lilt Pll shy(ilitnnl a 1(11 it 111 (Dod fill llli lIut ( ptotoJIIltlil IPtlllillg-- of pllllntnl or liuht tlUtllIlillal(I oil n (lpel OphotnJlllllI at rase hng-tlt (If 11 llJ Ill Ol It lollllil1lPtImiddott lloyidld with tIll P10]11 I 1110110shy
Ihlolllltt hmiddot Ii1llI Olllhi lIatioll for -1IpItillg UJlproXilll1l tply Wtl P ]Plwth )0 mp are HHlltk TIll Illldillg lliJtaillld fol tIlt 4-milutl tliall(~ll-
bull
bull
bull
RAPID PHOTO~IETRIC DETERIINATIOX OF R(BBER AXD RESINS 37
ing are referred to a table of equhmiddottllut~ previously p1(pa1elt1 on the
bull basis of 4-minute reac1inJ~ for tilE nmge of lot1telltlatiol1- of rubber or resins to bE elHOlll1t(led tmd gidn thtmiddot -tnnlillfr tillIP fill rUbbEt or resins aiter prE(ipitlltiol1 lwfolE photoIllNliI j(tltlill1 un IUade The r(middotnmining dllplllatt aliquot lll then HHllil up te ol1l1Jle and lpoundadillg ale marle ut the -tandillfr tiUlE iudklltll ill rhl tall1lmiddot for the final r(adillg~ -1) 111( milli1lnm or p(tCPlltllt- of lllhbpL (II 1(-in pr(s(nt are rpadholU a prlpan(l table of lquiltlput for tlll photoshymetric readings h1~l(l ill pnell e1-E on pxpPlilmlItal lhln 1111(1 u-ing as stimtlltlds pure luhbll in 1l1bbtl milllYb aIHI guaYllh ll-ill- lxIHlatt~ in resins detNIl1111lttion I
LlTERATlRE CLTED
(1) lUnSbull 1fl36 THE mURMIXTIOS IIF IOTA RE I III OOl THER llT~II
F1 bullrol IlY U(T1l0fll UfSlfi ~rrnrl r flm lt1 KEYS TI Bill Chern 114 44J-l59 illns
t1 ~ICPHHlObullbull T 1J3bull~ lUTHOO roa THE PtRInCAnu Or a(lIUl IRrIlHU It of TIn
PLRIHEU Htllllflt [ i Bill lallllall 111 Rmiddot 711middotj iIlus
I ) RHBERG P B Ul5 A METHIlO Or ~u(ronrll-nl Hi tIII rUIl[1 f71 ii illlI
bull 14 Hoss W flbull and HARDESTY J O
llH IR1ltDII Of HfITilIZfmiddotR DllIJS ltt 1 Yl fll Off gI bern JIIIlI i ~middotmiddotlf IIl
101 SPEltCE D nnd CuoWELr ~I L 1933 DETER~n-ATIOo OF RtBBER Ii nrllllpoundRBfR Iusr 1uI II1 amI
Em~ifl cttIliIa~~ r Ell i 71middot7i l11 (HI WALTER E D
1U44 ISO~nlS OF PRTlltSrr 1trHpoundV bull l UI n W lHHt (Tnmiddot 1ETS FROM GiYI l~iIl lItr Clttrn SII J UI titJ middotn9--C1 ilIu
17 J YOEbullbullr H lO~( roLORIlETRT 771 IPmiddot nl -W Yurk f H Plrwptric hmica
naly-II rimttry lUll XphHHlnmiddot~ y 1 1
11
HI) ~ fPHELolzTRf 57 111bull Lin xw Yk t H lt PhmeHt CblUlmiddot ila AnaiY~l~-(H lithrry and XIhmiddotILpfIY Y wirh enomiddot rrJlllrjr hy H KtlJnJU11 I
t~1I --- and ~ARVER L 1f41 nlua-w ~in L liLhr IS IP ll~ XIW Yrk
bull For-sale by th~ ~a~fr1nt~nf1ent Dt~c~~ogtnts-~ s t1i rArnn~ut Pn~~~ tJffieshy
Washington 5 D C bull Pl lU ~nts
bull
bull
bull
RAPID PHOTQlIEfRIC DETEMIlXATIOX OF HtBJER AXD RESIXS 21
to H 20 the )olutioll becollles somewhat vbcou5 and precautioll Il1Ult be taken to ttvoid bubble formation When it i5 poured into tilt Cllvettes
It should be lloted that both of these precipitants have an ftellleshymmiddottion It was found that when XHjOH was used in the rubber preshycipitant in pInt of H~~O~ the readings were -table l)Ut were not reshyproJutihk The lIl of XuOH in pInel of H 2SO j ran nHittble result as a llth H(HY(Pl WIWll til( li-P(l put lthatgtl in lublltl llnalysis or H~O illlP-ius anal)j wn-i uddint(1 thl eharalteliti(s of till liquid with pleeipitated ruhber or resiu in HI~P(ll-ioll n ren1 on the lpNmiddottroshyphotometel m tololinlPtprfollop(1 it lPgnlal lIlll II~ lxplaiHd on pHgP-I (Sl( figs 11 aIlIIl) Tid made it lloible to outain lEPJOshydlHibll tpnlt nntI (onplt1J1(Jttly till JpqnitPIl tlPgJPP of PJPcljoll
IIWIE(TI 1lt COl~101J)
Jtl thp ItJiPl middotxlwlillltnb hefoJ thtmiddot -1l]YIlIt allll pnmiddotdpitallb had lIptll ptoppJly adjutp(l it l fOllll tIuH till llP or a Ploltiw colloid -wll ltIi1)cJ [ttlJmiddotntl- imlIopl tll lmiddotpro]lIibility of the lPlllt JmUkllly ()Ilt 111 U lput lUlU illlihumiddot tOJllPOlUtl tpHd liglyeol teltlut( - llpanlItly IllmiddotlfP(] to lit til I1m t IHflll lImnnmiddott nftlr tlH filial prOIptlllll WtlP dlvPllill1 tlll 11lIlpfit (If thtmiddot [llltlltin lollohl wa Hot 0 natlv I1l(lhmiddotd III rlumiddot Ia- of tmiddot ill tllmiddottJmillaritlu it b [1 hmiddotjlmiddot til IIpoundgt Ir llH1 It liltr ill-llImiddottiT Ina lll ptlPII by it U( in ruhhfl mmly j 11If dtmiddottail fOJ tltt lllllmtlllll If thl plot pet in nlloid ~llntill tltlmiddotlImiddotmiddotlttlatiflll lIOlllllllhtiPI1 are iPllllll page
liTFHFEHliG COIOf
(hi II tht lllail 11111111111 that had til ill -111111 II urklll) om tlH method fot lublJtt tlIlO1 rpir- nlalv~i in plaut llllpll- wa ttl (lilll~ inare tIte (gt1[01 till to tIll ptP-PlHt f xi [aIWIIII- 111 TIlt amount of (olor varip from lUllIt tn -amp ]pplwHlI nlt rhmiddot lt IIf thE Hl(ltllial tllP part of till plllIt -lI11lhmiddot(l tilt hi-tlllY f tlll plaut mtteshyrial ~ub-lltInent to Itlllmiddotnmiddot-rill lliI 1011middotly OrllPI Inlw
In ruhlwr lrtl-i I Iii 1101 au Itmiddot 1Iplll11l by 111[ I--r ratmiddottilt thE -lllll]t with uptoIw or 1middotmiddotlIll-ol - wIdell [llllol- rlll loillriu nutttel autI thtmiddot lpill- Thi- howmiddotvt n(tnll- til lXtla -11gt1 ilt prlJ~edun) In lP-ill ltluay-i nllHufldy tlW[t j 11 1 1IO(PIlln fill the 11shylImya of hlulophyll Hwl rIlI-r middotIOII IHlttlmiddotJ dlH lUtl~ In plltIH withoUt alo aiftIriL till nmiddot ulttrll
111 pllIbIll1l Wi tilmiddotr hId h It-ImiddottHI tht Pltlpll 1 hlitlt lilt tlw tulllWlli tollImiddot uIwltllIIntut -lltUIhorlllllltll 1111 tIll tlettlllliIttwr IIf t 111 lWlrl-Uamiddot of bdt tl11blLlittUhmiddot r [1 tItmiddot preshyj
lipitatifll 1lJ llllllWI atbull 1iI- in III -1nrmiddottIi fHlttalldh nlrillU~ amount rf middotlorilig lIUlttll Iii lhll of ih lltmiddottllllhottohttt~l l~ol()r infrtl Hm II upd 1 rwmiddot tld~middottilmiddottll PlllItlhi~ f it j proYitiltl with tIll lilP--UlY tU(jlIdlllIlml tIltmiddotmiddot lllklllUIlI
EIECTIol OF 1 [EGTH~
-Ptfmiddott ral tracilull ru~lI gtIll fr 1 nllb t ~xtltd 1 lIlt-th vI iobmy1 ketommiddot lWtl rill [ Ixt lttltt ll UttollylaIiIitt1l11I1t~ ~-I itoiu YtHil)u~ typp of ~IHaylllt f i lItmiddot art hraquoil ill fio1ll1 ~l Th~ lp-nlt fill I11oohl uio[1t ttl willlr til tltN- fur rht IUiXtIUt iwliutll
100
22 TECHNICAL BULLErIN 920 U S DEP1
90 bull eo
I shyz 70LLI 0 a LLI a 60
LLI 0 50 z
a ENTIRE 2-MONTH-OLD PLANTS~ 40 b ROOTS AND BRANCHES OF ~ 3-TO 4-YEAR-OLD PLANTSen z WITH LEAVES REMOVED ex 30 a C CURRENT-SEASON GROWTH OF l- )-TO 4-YEAR-OLD PLANTS
20 WITH LEAVES REMOVED
d LEAVES FROM 3-TO 4-VEAR-OLD PLANTS
10 A
0
a Cd 100
b bull
10
80
I-Z 70LLI 0 a LLI 60a
LLI 0 50 z ex I shy 40 ~ en z ltI 30 a I shy
20
10 B
o~__~__~__~~--~--~--~--~----~--~--~ bull350 400 450 500 550 600 650 700 750 BOO 850
WAVE LENGTH lM~)
FJGcm O-Sll((middotlllll tramaniW1IHl (mrpS f(JI (xlmll 11011 n J1ll of jlta)nle tissur ill n 2--m1 Y011111P of (A) Illrthyl ji1I1J1ltsl krtonp 1111(1 (ll) nt(middottQnyla(umiddot tClIc-C(l1osuln a-i
bull
bull
bull
RAPID PHOTOlIElRIC DETEH-UXATroX OF ntBHEIl AXD HEstxs 23
ThE dula Pl(S(l1t(lltl indi(ntp Ihut 101 Illp ulimls llHthyl liohutyl htOlIl (lxtrHts (lI(I r(dolls of Il1Hxi11111III nigtol]gttioll wiH1I all (is-lIb 11 cOllsic1(]((l n1( blhn(11 wn ( ItIl( Its lIO to () I1It~ nlid Ii to Iii mJL
WhllNIS tlw I(gions of 1middottnL(s( light 1lnlllittamp al(l lgtPlW(PIl wan Ipllgtltsnr) to Ii nllt jW) 1I1JL nlld alio Silllill1l 111l1b (n SI(lIlId 101 nc(ton ]altmiddot(fmiddotollp-(llloolp ~ pxt Ill of 11a 1111 t illl TIl( (1101 du( to lolo ill tlw litlltitl a 1Il1 lullll(I tH lPill- hanmiddot bpllI PI(_ ipitated ma he 1((I1((d to fltI ynbhing poillt II ph( illg OJ illshylmiddotJall(( WIWp balld nhm ()) IIIJ1bullbull[1I111 lxjlPIitllll1b Illln -h()1 that Ih( lIIot uilahl( WHYI lHlIJ fOI 1-1 ill 1l11J1l(I HIH11Pill- illllllrsi i-in till IlPighl)()lllll()(l of ~llIl1lt bull
bull UIlIilHlIy of n typhn] lXPllillllllt to )10 l1iP(tiP ((JIlllo( of (ItOIS dul to lOIOl in 1llblnI Hnd Iill xtnumiddott 11(11 IIIIolp t jUl i p1llelll((l ill tub]lL Till llhlllt- 1tpIO]II Hnd ((llll~()h whit-h UI(I ](]Hllilltl n 1I01lllIhb1 01(111 lxt 11111 IIll 1llll)1 nmtp[in I and )(middotills Tid IIlnkl it poiblp nftlI tlIp uplll1tillll or tlll o1PIl( (0 [niH lip 1Iidl1p~ of lI111 11111(( ill lit ll11l1)[1 (llnlIb nlld Ihll
Sl(ll n ol1lliOI with tllP olnl IJllt illiollt HIl Iltlllll llllI (Ill ltllthpl prpipitnnt j Ihll1 nddld OUI ha a lIilPt lP( of till lIiciPlw of WH( lllIgth 7) lUI- ill llilllillatiu (nnl till tll Ixtll1I101l ()lll~
Tuu tmiddot-Elilll IJl flrldillY 11-1111 lrlllI IjfJI til islII 1 1(1 ([rllt IIIIIJIlIr JiIlIt~ if 1Il( Ihll 111111 k til I III Ilrln I 1Intd tf 11111 JiSf fill I I II I tIII Ilf Iilltl 1f1JlIIillII1f I Till 1[ 1 IId 1 (I (middotIt 11111 (I1I1iI1 1lf1IWtlfJlIIllfflr p middottrllhIJ11 II J III 7IImiddotIa 111 111 lilt jJIp 111 wilTII
t~t tnVIli~ ~nn r kn t~ i tmiddot ~~l Jr 1middotmt ltlTt
HmiddotOtt ~I~ lin t I ~ 1 t~~l ~qrmiddotthtmiddotrtwb
Hult-middottltlru t T Hw ullut rHtt~ r II I ~ PH~lllt
A~tmiddottHHjmiddott~rjd rl ~gtllh 1 tn~th~ ~ ~ middotI lt~ b w bull hmiddotth~ 1i~lIhun 1 Ii tnl Illd1 -11lt1(11i lullI lUI tJl ll~ t1~11n( I Ihan1li flfttIJir Ult I Uuhtltt ahuul l(hmiddottHmiddot~t trv r fti HIt lftbyl tlonhUt)1 k_hIl( 2 m~ fmiddotf tuhlHmiddotr In mlth~ llmiddotlf- 1 t r
t r_~ t j
Arhlitlltd ~llIIDHl NcWitn1 ( Ar-(lt()nc~middotttrrtrt ritJJI~ -Iu nllJtl4-middotr
ACtmiddottflnp fmiddotxtrn( ~ T-P511ftf tn mtmiddotth~ 1 ~difmiddotut~ kdn 2 nltt ulruhhtr in Un-tIl lltbu )J~IYt
rUth(Hl~hltlft HhubU
Illlh(I(t tttUtUt hUbtl til J ~jlitl(J Hilllll trtIIImiddotjtl1ll
(UShl I ~tlO wHllolH rulh r (middot1111$0]( J~rru t t )lthyl 15bullbull1middot1101 klll1l
Ili( UHUicbcul ~((i1rUtl ~ulu1iin 1middot lIUIll Ilti lrllltlllt I Ruhhr llt1thuI r1 -1 Irld
ltlt1111Sh 2 nuz f)rruhl~rm nlith~l tu- h f nt nil~middothgt(H] tlrlftmiddot 9lUtirtl middot1 1
rlcltfl( H(l dnllltml it
(IISllhH~rI( Iultruhtr CII05 1v ltTlft I 2 UI~r ublwr In llldh I hlt~1 11) lgtjdvr(llsl~9rlltmiddot middotlmin ~ I~ gt AIHItilltl no IrttipHallr iI
~ Bbnk 10ol m(thyl i~tmiddotut~i kdHn H 1 m1 j~~ l1rH-t lt~tlfltmiddotn sf n it ll HltlMjftr~nol O2~mlJ ~U~1o-ulp ti~tW -xtra~middotl(lt1 ltt 411 ml bull ie f Ct- kft rt t~ tirattJ middott ill r u l1kn ttJt
in metltl isobutyl kNqnf nn~i mljp ur tmiddotmiddot ~oml ~urr tttl i t w ltJj1JH kt 4t 3 nlank 1 mL((l1t~rthmiddot(middot mI mttr~ ~but a kmiddot tmiddotc d 11 ~ gtli~b~ hifIAft- fl~ lL lnti 149
ml8(dlfilll BO bull 02 gm guayule U$Stl(middot xUlClt-l tf(h tft wI n nmiddotmiddotmiddotlgt 1 lznt on tmiddot ~Jt r~1 ~~u~~ H~ iI~ thT
24 l$CHNlQAL BULLETlN l20l S DJltJPT OF AGHl(CLlOHJltJ
In table a is pl(sentc(l such c1il((t edlt1tIHC showing that thc (0101 Ixtrnetccl from guaYIIle tisslIe wit h II(P(OIl( n nd (pl1oso[yc is cll(div(ly sCIe(nec1 out by the s(lp(tion or wnw length )0 miL Oil t1w SI)((IOshyphotonwtpl This tnb]p all-HI ihos thai thl Juhlwl altl(l((1 (nn IJl quall shytitntivcly 1(I(()(Ipltl in tIlt PI(ilIH( or Ih (o]OIplnwPIials and Illsins and tlmt Iuhb(l WtlS nppnlllltly 1I0t (xtltI(((1 110111 11l glll1I1l lisslIt b~ tlHSP SOhlllts Thls( ((suIts ginmiddot (OliIHillg (idJt(( that t Iw IISI of waYl llngth i)ll 1Il) OIl till SppdTophot OIllltPI ii t hl 1101(1 p(oshy(ellule in photolllliTie IlIlalysis of luhhlI OJ l(sin-
SELEGTIO- OF )IOiOCUHO)IAIIC ItIIm ((1111110
On th( basis of th( IPHIlb shoWIl in tabl(l 1 al hlllpls (1( IIln(lp to SPCtl lC the PIO]Wl 11101lO(lIOl1ln til Ii ltlJ ((lIllIJi nIl ions 10 llIiOlS (oIOlimet(Is 111(gt 7W-Ill~ filtpl flllnhwd 101 til( I1~lI1l photoshyplpct1i( (o]oriJl1ltll fol which Ill( (hlll(IlIiitit~ oj t hl Ilda he light ilUIlBlIIhiSioll (t) elll nn -hO11 ill fig1lle 10 iws satlsfa(lolY IPshysultl 111( iiO-mL HitlI olllhintioll 101 whkh ttp (middotIatinmiddot light tlnnsmission (ullmiddotis a 1-0 showlI ill figllll (I is -nthdnlto1 hut this is not stnlHlnld NtllipmPlli
Up to fhl PlPHllt lIS(middotflll pound11((1 (ulllbinntions jn lltl iOO-I11L Iunge hayc nol bllll SlClIlld 101 lhp Klpt 1-1I1l1I11PISOIl (olOlinwtll bu fnltlwl nttCl1lpti 1( )(illg IlIHd
TJIpound OF ST~lmW AFTEH HIIJ1EII Oil HHSIS rlll~CIIITTI(J
~ considl1ltiol1 of ttp lillll of Inlllling af((1 plpeipital ion of 111gt)(1
01 l(sinSTlOIll ollltionis impoltant J(jl~ thC1HI(Plltngp of light IInIlSshy
11 rshy10 f shy
09 f shy ~750 Mil- DOMINANTI
~ 08 cshy I WAVE LENGTH z
I III III i O7 - I III
~06 - 05 shyw
a
Igti= 04 - 720 Mp DOMINANT ct WAVE LENGTH- ~ 03shy
02 f shy
01 t shy 1)O~~~gt~- J 600 700 800 900
WAVE LENGTH (Mp
bull
bull
bullFIGlRt IO- COJllPIUlItiw ~IW(middottltll tlnIlRlllii-lion (II (IllP( 101 1i11(1 olllhinulloll
with dominllnl Il(lllllgths at 720 and 7iO lUi
bull
bull
bull
HAPlD PHQTQlfE1IUC JjETER~lINATION OF Rnmrm AND HEtiINi 25
mitted (spertrophotoll1eleL lCuding-) Ol light (1 (tClcrl (phOlOshyJluol01l1et(L lcndillg~) i~ StlhjNl to (hangl
]fjt~l1le 11 and l~ show that ill til( (asc ot tJaugtIllitteltllight llJHC th~ (x[llliHlllIlnl (oIHlitiOllS tllpl j lilst n dtlln-e ill Pll~(lltngl or UllllslllittnlH( follrnY(l by It ptJiml of lClntin stability with only sliuht (1111 tHn- a f(Pl a lIt1ll1btJ of minutes The light t UIllllitblllll t l(1 ill(Iln~(s This lIIay IJP llllllJltlli7P(ll1 ffl II ow 1Ilt )( f(( darI oliIII tIIlIlNlIlitt(IIIlfJIIlh (iditilIiid Ilil1 pllIipintnl )uoshyIn Of ( 8inx in (~f1( I~iUII i~ Ild stahl I 11 itlll If 1inl nh prlshyilli(ioll of 11l1d(1 II IJIX f) jllIli II (fJJltfiIIlilty slllMI IIriot 1) IIIPldUnl1i tll(I1I rllltltilJl oj tJi~ Jlt jiot IUN ilUf Jxl1 will tIt( tOWI IItlllilil I 1llIlllblJIol I ill I~11l11111 d ill till ifjuids JjOI scnttplltl light 011 till phololltHJIOIl1lttl till dilPCt ion 01 elangl b tlw IPrfIi (If that illrli(atPll rOl tlulll1Jittp(lliuht It Itlll b( llluliJr I-(Pll that if l(middotndlnJ- IIIP mad n itl I t lIP ~()ll1d()lb lpalll this pllioJ of nmiddotlatirp tuigtility tllP llLot tIOllt thi Olll(P (nil bl IPdUCld to tIl lltini III 11 Ill TIll l~adiltg (illH~ bbll Oil tlHl datn rUl lublwls and llsinlt Illl ginll ill tnhh
50 r----------------------------------------------- f shyZ
~ 40 ~----~W~A~V~E~LE~N~G~T~H~7~5~0~M~P~~~~ ~ --------------------=-=-= ~ 30 f- WAVE LENGTH 540 M~ _z _____ ___ -=- __ _ ~ ------shyt ~_=---=-=--I GUAYULEIII 20 -Z HEVEA ltt II KOK-SAGHYZ f shy
4 6 8 10 12 14 (6 18 20 22 24 26 28 30 STANDING TIME (MINUTES)
FIlirtn 11 Emmiddot of wav hll~rh Il li~ltr tlall~lIIit1alHl aftI IUIlItHt -Imlli lug 111m for guaynh llmiddotn 011111 middotiolIlJh~z 1111111 llijlitul1 flolll 1lHlh~ll1Jllryl k11II11l ~(lilltlll h~ lwitlitll 111Inu1 111l~1It1 2)1111 o1U11111 (Helillins on (illllun tlunhll IlIIJlllw]ntllW111 lutl(I[lholtllllltlt with ijUjt Wlnl IHI Ilf1 I
11 EFFEGT OF Hbli 1 -()JXT10~
Tilt lnblwl ~()h(llh pxtnl( till IPillgt ubo It 1m nllu1- bellt -~atea thut ~lll 11-111- tUP olnbhmiddot ill middottIIlIlOl ~1It tlWIIJI( my U)t PIl (tlIHatcl WIth tl1l lullh(t I tahle lJ 1hln 1- -1111 tIll (llllstlOll of nny p()~iblt tITptt of XtIIl11 diflp]lws ill ((JlllPllttUliollS of 1l-in lil lolutioll alollJ with till 1lIltbpl TIU data ill wbh +ho on tIl( hn~is of (olorilllPill ladillU thaI tll( IIUOIl1t of lnbbll Plllipirntld 110111 Ilwthyl olnlld kptOlll olntioll IJ 1li-jHlllnt 1l)04 in 1-llltlIllt ethallol)- not amlll hy thl llllNlI(l of llvin aU1ouut of llins inolution bull
-----
26 rECHNICAL BULLEfiN 920 U S DEPl OF AGRICULlUHE
100
90
80(I) C)
z Ci 70 UI a 0 60 a ~ UI ~ 500 ~ 0 I Il 40
30
A 20
0
100
90
(I) 80 C)
z Ci 70 UI a 0
60a ~ UI E 0 50 ~ 0 I Il
4-0
30
B 20
0
--
--shy ---shy---
2 4 6 6 10 12 14 16
---shy= ~ ~ shy
-
2
025 05
10
15
20
25 -30
35 40
SO
-60
=70 80
16 20 2224 26 26 30
OS
- 10
IS
20
2S
30
35 40
-50
-60 -70 -80
bull MGPE 25-ML
VOLUME
bull
MGPER 25-ML VOLUME
Florm 12-EtTld (If till1l or Slllldill~ 011 light transmittallce (01 (A) gUllyulc lnUIl(I plccipitllitd frOIll llltt h~l isobutyl Ielollt solution Ily neidilic(l ethanul bull null (B) gUllyule ll~illii pre(ipitated flom aeltoll~lllcetOlll-Cl])osolY( 3-7 solushy11011 by H(illilip(i l1U (HPlldillg~ nt -lIlillult Ifllpluls 011 Evelyn photoelectric colorimellr with jU-lllp tlllll alit U-1I11 npN(lle spp also table 2)
bull
bull
RAPID PI-IOlOMEllUC DElEnMINAlION OF RUBBER AND RESINS 27
TADIbullbull ] 4-ReZation of amiddotmount of middottbber pleeipitate(Z Oln metltlIL isobutyl ketone 80lutions by OS-pereent H 2SO in 95-pere(lIIt ethanol to umollnt of resin8 udde(l U8 indivute(Z by colorimetrio readinU8
(Rubber ami resins cnlculntcd on bnsis of amounts in 5middotml ullquuts of extract from 02 gm of tissue in a 2fllll olumo( bull
Hubucl r~cocrell whcll rcsins nddcd as IndIcated Htbbor al1dcd (pllcollt) ---shy
__________bull_________ ~_12rpcrc~15011crccllt 7511crccnt IOOpcrcent
PerCtllt ercellt Percellt Percellt Percent o o o o o) 50 250 263 252 25000 500 500 500 500 700 750 750 751 749
1200 1250 1250 1250 1250
EXTRACTION TEMPEHATURE AND TIME
Typical experiments to detllmine the time required to secure maxishymum extmction of rubber und ltsills at 115deg U Ilre sUlIlmarized in figule 13 the solvents used-methyl isobutyl ketone for rubber anrl Ilcetonylacetone-cellosolve 3-7 for resins extraction-are very eflicicnt since under the conditions indicttted maximum values were secured after 30 minutes of ext1llction The most eflicient liquid for the bath (lig 1) used in extrtlcting rubber or resins is ~ high-grade cylinder oil (S A E ~O) The sand bath and such liquids as glycerol have proved unsatisfactory
RUBBER AND RESINS STANDARDS
According to the National BULeau of Standards 1-_ lhclc Is no gellcrnlly recoglllz(d standard lIIutcrlul [ior II rubber standard] The rubber hydroCllrbon ill llifferent samples of conmlcrciul smoked sheet or pale crepe from heclI pluntlltions nries from l~ 10 04 llercent of the totul nutletmiddot the most 11Ioruble conditions Of preparation
McPherson () has described a procedure for the pLeparation of pure heve~ (Hevea brasiliensis (H B K) MueH Arg) rubber from crude rubber or latex In the absence howevcr of ~ generally recogshyn12ed stalldard for rubber hydlQcllrbon [caoutchouc (CnHUs) xJ the standard adopted was that of the relnthely pure product secured from gunyule tissue txtractiotl nccording to the Spence-CaldweU method (5) or the motlified PIOCCdUlU of Hohnes lind Haasis (p 2) The details for constructing the calibration CULes are given on page 10 Standard rubber samples apparenl-]y can be stored for a long timc under the conditions des(libed on page 10 The duplicate colorimetric lendings for glULyule rubber newly extracted by the modified SpenceshyCaldwell method were ()J2 ench as compared with US) each for the sample extracted by the same method but stored 1 years In each case colorimeter rcadinllS were made on mixtures containing 2 mg of rubber in It 25-1111 Yolume
The selection of tt suitable standurd for guayule resins presents some dilliculties Tll(~ acetone extract of gUllyult estimated on (l gravishymetric busis~ for instance proved to be variable depending on the type of tissue sampled or season of sumpling because such fractions as
COllllllunlcntion dul(lt1 Octohtr 22 11H3
28 QECHNICAL BULLEQIN 920 U S DEPT OF AGRICTTIIlURE
16~==========================115 shy
14 bulli= 13 z ~ 12
ffi II Q
10 c w 9a w
8gto () 7w a
6a w
5en III ) 4 a
3
2
A 00 5 10 20 30 60 90
14~------------------------------------------- bull13
i= 12 z w II ()
a 10 w Q
9 c w 8 a w 7gt o () 6 w a 5 If)
z 4 If)
w 3 a
2
o+B~~__~__~____________~__________~ 5 10 20 30 60 90
HEATING TIME (111 NUTES)
lllGUltE 13-lDffect of time o( lICntillg O2-gm samples of gunynle tissue with solYlIt nt llfio C on lo(OVl)ry of lllhlJer alld 1Isim Lt HlIhblL extracted with methyl isohntyllwtone B resins Cxtll1cted with aCftonyla(etonc-cellosolve 3-7 bull
chlorophyll are weighed along with the resins in the acetone extruct but are not estimated by the present photometric method (fig 0) 1he use of a diffeJent stanclttrd waS therefore indicated
bull
bull
bull
RAPID PHOTOMETRIC DETERMINATION OF HUBBIm AND HESINS 29
The resins standard selected is based on n relatively pure source of resins the rcsinous exudnte 011 the stems of guuyule plants IJldimishynary expeliments with the resi nouS cxuclate from diffcrellt gllayu Ie strains of various ages indicatc nHlt there is little YaLiation in this subshystance on the basis of Colorimct(r readings 011 2-mg aliqllots of 01shypercent solution in It 2i-ml volume (tabl( li) Expelilll(lnts have shown that the air-dried (xuclate contains 3RtOH p(Ic(nt of -volatile matter This material is l(latiyt~ly stablp ill (OlllpoBition and is npshypurpntly on ly slight ly hygroBcopic as shoWIl ill Ia bl(1 1 Tlrp Ipsinolls exudate may be jJleplpd in two wayi-i fl liSP as a stallClHld-(l) the clpan exudate is clripd iol Ghouls at ()1deg C at W indlPs of a(lIum Hnd aftclbCinOglOund ill a molfalis 1)I(spI((I intn airtight COllilinel OL
(2) tllP Cx7lclate is clissolllt1 ill a(lhllll and filtplpd PlactieaJlyall of the acetm1l is thpn lYapolntwl olt OPI a stlam or atCt hath and Ow residue is dripd ground an(( PI(sPIld as ill tllp fin lllethocl Tlwse two prepalHtlolls a1( (ompalpd in ta hlp ) 111( (((tails fOl ~t()lil1g the resins standald and (onstlllcting the calibration CUITPS alc given Oil page ]2
lAIIIg fi-CUIIIllrsoi (lJ lIr-dr(1I IIIIi 1((11 II II-()I-tr((l l(sil~ 11111111(8 of I II 1111Ie
[Colorimetric rrndill~s 011 1~I11 phulll(Iclrie eolorillJct[lr with i~()middotmll (100- to iiOIIIIl) fillcr [lnd 5-1111 lIperture preeipitantl part ofO5middotPIrctllt 10 to 5 paris of IIOj
nupliclllc(oloritwt([
nIl(lin~s (hIlSlcAg~ ofSlmillXo JrNliltlCllt of fPsiJI$ L1Xtlrlntp on 2 IIIg ofplanls fllsins (XIHIIlt~Jwr 25-1111 vol
tII1(1) 1
leflTs Various _ bull ____ bullbullbullbull 3-9 Colll)Josiltrlairmiddotltlricfl bullbullbull nf)2 002
])0____ bullbullbull _bull __ _ bullbull ~-l Composilld (ri d at n5 C in aUmiddotimh lWUUllJ for l (jOuj(ja hours])0______ bullbullbull __ bull ___ bull 3-0 COJIlpositld disso]NI in neptolll f1l1erNl fl(lf()ll( GGO i(jO (Ivaporntld olT OV(1r Stpl1l11 halh TesidlH drl(ld I1t fi5deg ( ill anmiddotinch VIl(Unlll for 0 houlS bull
middot106 __ bullbull _ Jir~c1rild_~_~_ _~_ ~_~ _ ~ ____ _ __ _ OUu GOifina_~ ~ _ ~~_~ ___ _ _fln~ ~~ ~ ___ ~ __ 6(imiddotI tiliA H)[_ ltlu bullbull i18 tisSflOabullbullbullbull__ bullbullbullbullbullbullbullbull lt10bullbullbull _ tillO llitO406__ bullbull __ bullbull __ bull __ __ lt10_ Utl2 fon591_ fo__ bull liGa oOa 406bullbull _ __ lt10bullbullbull_ li5S OM
j Ph( vnluls in Uw Inst COIUIIlIl indieatp thnt gunyulp fesinous (IIHlnt( wlwtlwr dfircl hi Yn(tlLJ1l1 wilh L~ perc(nt loss of volntllt wutl pr or tWl c1rild giVPd npproxil1lnh1ly t Iw snllw colorinwtCr rNHiing- 011 till busis of aliquot~ cOlllniuiug 2 IJI~ of flsillS lXIHlntp l)tIf 25-mI volultl( Ihil- illdicate~ thl11 Uw UITW IJ1flS~ of olnshytile mntl(f prt~(iJlitnt(d gins npproxilllntlly Uw $1II1l (oiOfirnl1tlf ftudiTlJs ns tho ftsidtw A pnlill1jllaf~middot (XIlltrinllnt indicutls thlli th VUllltill muller l(lIlSists of thl Ilrplne oil fmcl ion I5-(1Il gtnplls or rlsitlOtlS (lxudntll gnvll by stPll1U distillation nn Uefllgl of 011111 of jl(lfPlIW oil with npproximHte tilllsity (If OHIi lind lhus rrprlsll1ll( IlPIJroximllt(I~ 01 Jerccllt Of t he original weight 1hls lllrClnlage complrcs wllh 38 llltrC(ntlost by drvinI( in IICllnllJ
aSplusmnUH perceilt or orlginlll weightlosl
The wailnble illfolJllntioll on tlH (ow-JitlPllts of the gunYllle r(~shyillOllS exudate alld tl1( HeetOlIP ext act of gaylp ti~slw is sllIllmarized in this paragraph lYalttI (u) alld also Hangcn-Slllit lind his coworkshyers 16 reported that 20 percent of the resinolls exudate from gUltyulc stems is parthenyl cinnamaie (CHuOH=CHC020 11JI2r) Steam disshy
15 (OIlIJIIIIUicatioll flom A T Haai(II~l11it llId (0011(11 Calif0111 ill Tnfiitnte of Tccllllology Past(IlIJI Jhps( wOlken al Htud~ing the COTlHlitlllllts of the acetone extract and other conlltituellis of guuyule
30 TECHNICAL BULLETIN 920 U S DEPT OF AGRICULTURE
tillation of similar resinous exudate in the writers laborntory has yielded approximately 4 percent of the whole as the telmiddotpene oir fracshytion Haagen-Smit and his eoorktrs nportec1 thttt about 25 percent of the acetone extract from guayule branches is parthenyl cinnamate and 6 percent of the bark (ltortpamp-phlotm) extraet is parthenyl cinshynamate These workers fm-thcI reported that 25 lwletnt of the nc(shytone extract frolll bLllllches is a compound with the tlI1pilicaL formula CBoH400a 1 percent is a compound llwltillg at 2P to 2T5deg C and 1 percent of the extract from the ]eav(s is tl (olllpoulld nwlting at 100
to 1710 1Valtei (6) reported that 3 to -l perc(nt of the tI(eton( txtract
of leaves and flowering StPIllS of guayulc eonsists of waxlike substances soluble in olgallic soln~nts but insoluble in at(l and (on(ent1llted H 2S04 The flactions mentioned on the basis of (onHLTutle esti shymates of amoullts actually isolated tlecoullted for about H ptIcent of the totalncetollt~ so]ubles extracttd from tll( guuYllle 11 rub The other constituents ltlilaill to be i(](ntifi(d
RUBBER AND RESINS CALIBHATION CVHES
Typical culibndioll Clllves iol Iuhbpl and I(sins bas(d 011 (ldtLminttshytions made nccoLdillg to the plocCdmC outlin(d 011 pages middotb to 1G arc shown in figulPS 5 and 1+ The spCdlopliotoll1lttL en (OIOIjlllctCI readings are plottCd on s(lIlilogalitllllliC pappi ag-ail1st (Il 11IbblI (011shy
100 ~ 90
80 ~ 70 ~
z 1amp1 0 II 1amp1 IL
1amp1 0 Z
60
50
40 ~ltI 30 ~ en z ~ ltI II ~ 20 C) ~ oJ
10 o 2 3 4 5 6 7 8 9 10
RU8BER IN 25-ML VOLUME (MG)
bull
bull
bull FI(lURE 14--Ctlihration curve fotmiddot gllftYlIlc lubb01 (Hct(lings Oil COIPIIHlII tlOl1hl(
monochromator SlCClrophotolllet(r with 7fiO-11IL Illtel alld Hllp Wll ( IHlll()
bull
bull
bull
RAPID PHOTOMETRIC DETE~MINATION OF RUBBER AND RESINS 3]
centrations From a casual inspection of these CUlTes it would appeltr that Beers law does not hold Actual tests indicitted that Beers law was applicable only within a narrow range in the upper portion of the curves The analyticlil results on the basis of photornetric readings nre therefore calculated by direct reference to calibration curves or from reference tables of equivalent values bllscd on the cnlibllltion curves
Calibration curves for kok-saghyz alld heyea lI11tulltl rubbers and Buna S (GR-S Chem Gum IV Goodyear) and butyl (GR-I Standshyard Oil Co Protoc) sYJlthetic rubbers are hOWllil1 figure 15 The samples of kok-saghyz rubber were furnished by the Diyision of Rubshy
100
90 ~I) ()
z 0
1amp1 a
~ a
80
70
60
s 1amp1 ~ ~ 0 ~ KOj-SAGHYZ 0 l Il
50
HEVEA~ ~
40
100
90
~ 0 80z Q 70a Co)
a 60 ~ 0 0 x 50Il
40 ~----~~----~------~------~------~--~ o 2 3 4 5
RUBBER IN 25-ML VOLUME(MG)
FmUIlE 15-CaJiblation curves fOl kok-snghyz h(YCII Bunn S lind butyl rubb~ls (Readings on gy((yn photoelectric colorimeter with i20-lIIp filtpl and 6-ml aperture)
32 TECHNICAl BUIJLETIN [)20) 1 S DEP1 OF AGrnCUIlfURE
Iwt Plant JIl(I~t ignlioll of thi BlII(un and (1( l))(parcd according to 11( SPltI1((-Culd (]] (6) PIO(((lllll Hlpt pal( CLPPe was (xtmch(L with acetone blI()Ieit W 1I(gt(11l a ttnlldal(l
SEXSlllVllY Ol~ llETJIonS
By lip pIO((l(II11P olltlillP(l 011 ]Hlg( +n Iowa (lOOl IIIg (11 1111i(l0shygmm (gHlllllla) of 1hblI ill a 2)1111 yoltll1ll (all )(gt dltpltld Oil tltl Col(man (lohlP mOIlWhlOl1lHlOl l-I)((t 101 l1lOt 0111 ci( I ill1ilnlly 001 mg of Iublwr ill a 2J-1ll1 n]ulllP Illay bl Ilad Oil till EnI)1I photoshyllectlie (O]oLillllt(I Thll ya lllll- 011 tilt IHl-i- (J I (xl ad iOI1 fmlll 02 gill of til-lI tH(JI(lillg to tllP -lllndal(l jll()(pdull 1(PIPStlIt IlO()2J tlnd 002) P(IT(lIt of llIbl1ll IPI)(((inly bull1t1lollgh -lI1t low allils can be d((d(middot(1 il lIoullt1 Ill IPtllizpd thnt till PIIOl ill PlI(Plltng( or tll( al110unt dltlIllIilll(J i ltlatlpl high ill tili PIY lo Itlllgl 111 aetllllllladie(middot Ill( lopl lillliL 111)(1(1 lIw (ollllil ions of tlil ]lI()(lltlIIIl u ol1tlinpd ipt at l11 11I1 or 1111gt11(1 illt i-1ll1 Ollllll IlPIPltPlltillg 01 p(gtl(pnt of JllUiJtL un tlll 1Hli or (xlla ion rlOI11 II rlll of tisSIll
EIlIlOH COSIIlIHIIO
In Oldpl to H(IIp ill )1lHtPltt pl((iioll illlpIi1I- it i lH((SSHI to slnlldHIdiz(i rigidly 111( Pl()((dlll( 0 illdi(ntpd Oil pnglt- - to J( If lids i dOlH tlip lXIHlinwnlal PIIll is t(middotdllld 10 n ndninlllill
Illlt pl(iioll of (hI ]lIPPllt 1IHllwd Oil til basi of ]llllP llIllJt1 alld Ipsinssollltions call hI jlldgl(J 110111 figllll Hi lileh lio- til HPIlIgl d(intioll oft -illgIP lI1lnSIlIlIIIlnt in lHi((lltagl of Ill( alllOllllt 01 Illhshy1)() 01 lpsins d((PI1I1 iJlld TIl( (1101 PlI(Plltaglt H1( gi (1 101 OJ) to
RUBBER IN 25-ML VOLUMEMG) 004 01 02 03 04
i= I I IZCtOW
fbA ICtU CtCt WW a
01 02 03 04 05 06 07 08 09 100 = RUBBER (PERCENT)
RUBBER IN 25-ML VOLUME (MG) 10 20 30
~ I CtZ
bBOw Ctu CtCt Ww o I~
010 50 100 150 200 250 RUBBER (PERCENT)
RESINS IN 25-ML VOLUME(MG) 10__ __3-0_ 40 50 60 70 60 90 100--_-- 2_-0
Ct~ -r- 1 I OZ
WCt UCt b C wCtW
a o I I 150 250
RESINS (PERCENT) o 10 50 100 200
bllI 1tI W-Yllnl dtd1 ioll I I 11l1 11IlI11 1(111(11 1 III Plll- IlIIIlol1 01 IIim~
bull
bull
bull solution Il basis J o golH of tiSSII (JlILCl-nt (11(11) for (~I) (l)1 til O 1I1
of luhllpl lin 1 III I (I Ill of lUhlJPl nllll laquo I J to 111 nlg of IlSlllgt (Itllillgs on ]iYllyu pllolwh-llrk CO[IJlilll(-(PI with nOHIP Iiltlr lIntl U-lIll allcrture)
RAPID PHOTOlJElRIC DELEHlllNAllON Cn HUBBER AND H1~SINS 33
10 mg of rubber anel1 to 10 mg of resins in a gJ-m1 yolumC For
bull
bull
bull
comparative ptuposes the leslllts arc also calculated on the basis oJvershycentage rubber OL tltsills in 02 gllI of tissul As WOlllL be expcet(d the error increases sOIlHgthlf for 1(lali nmiddotly low COlHell t1llf iOlls oj rllbbeL or resins The curves in figure 1(j s1l0 that ill til(gt Illlge Ol to 10 pCrshyeent of lubber the elTOI rangts Jroll1 abollt Ll to II) ]IlC(lIt abo(~ this mlllc tIlt (ITOl d(((ts(s to (ollsidlItbly ltmiddotss (han 1 1lICPllt of tlH mllollnt ltl((Lmill(d Hil1lilally in tlH (lISl of l(sins analysis (fig 10) the ltLTor is (onsit1eIubly INS than 1 PlLllnt ill (he lallgp of 11 t~) ~() penPII t
In nil ([lSl of lllhblI alld (sins lx(Inltpd tIOIl1 (issups Ol addcltl to tisslle lxtlads (s(( tabhmiddots (i H) illyolillg ll01P o(lllntiolls the eLI01
is hig]wl thun that indilHtld in figllll ((j Im pUIl Ill )])p I tllllllsins solutlOII
COlllUCIIOXFOH IXSOLl-IlLl~ Ilgsqgt(Jg
111 th( Jllo(pdulP ollllillPd 011 paw I till illsolllhll isSII Ipidll( tflpl (xttlw(ioll is (Ptill tlw lIask l(lll till xtlct i l1wdp up to yoltlllH It is not rOllPllipnt (0 IPt()PI qWlIltitati(Ir III(lw[olH a 11(1 pllooll extlnlfs of guuyull I is-lll alll thl1l main t11l111 up (0 YOIUllllmiddot bpCaUHI sllch all additiollal stltp wottld]) tillll-C(JllS11ll1illg Th( Iogiea nll(gtIshynntin is to mnkp tltl lXtlUCt Llld Ipsidup lip to OllillH in till original flask andi llPSStllY 10 llwlno tl OIIpdioll wlHIl (allIlnting [hc llshy
Hults f(JI [hl oll111lC displupd hy till ins()lllbh llsidll( III it l)picat (IXpednHllt (ollsisting of Jhp lppJiea(iolls if was Iollnd llftt at ~iiO ( 02 gill 01 Iuhhll pillS IPill-fl(( lisslI(gt (lollpdll fot llwistUlC ou basis of dlyillp ut lOW 101 ) llOlll-j (lbp(ld only t~ llllUll voiul11P of OOk7D~- OO(lOO(i Ill of lllthyl bolnl(yl 1lIOll( (lplhlli(al-t(Tnltle sp gl () Ii I ll(Hli (j at ~)) -gtitllP tl1(gt 1It101111( () r t is-lIl xt Iadld j sl1lall til( PlIOI dul to Ill(gt insoll1blp Ip~idll is slllall III [0111 ill( wOtk it (all lJp diIpgal(ll(l
]hcon~lIY OF HllIllgl AiO HESIS AIH)gl) TO EXTlIACI OP
GlYlLE TISSlg
Tnl)ll G L(IHpslntillp (ypi(nl llld(~ SllOS (hat all a plngl of HIOK PlI((nt ot lltl pltl( Ilhl)(l acldpd to tllP Itll h iolJut1 InmiddottcJllP xhnet
of guayulp tiSI1( WllS 1l((PllIl Tlli nllintioll flOlll (olllplpU I((OYshy
PIY i within flll pxp(IiIlHuttllIIOI ~illli]llly fnbll Ii llows thn 1111 llYlIUgl of 1O(1~ ])(I(Pllt of gllllYllII 1(-i1l- add(d to II( (pllosol( (xshytrae of IUllY]l t i~HI Is 1l(oPIPI
THl~ (~ Hf (Off Ill of 1111)( J OJ I~il~ lItfI(( In ~(JI1IJk~ Ilf (111 [lI1Il fI2 lIII
0 tlUfllllit i~~I1
Instrument
---- ----~---- bull shy 1(1
Colemun ruono~ltrOUlllt()r 2t) II sJl~ctroJlhOL()lIIeter with 2tJ I iflllllI wnclength Fetting 21 II nntl 0-1111 WU HI hUJl(L _ L U
Ill 7Evolyn photo~lcclrie (olor JU [ imctcr with iO-llIl filler IV (I
H1 0 t I I
llImiddot lUn WII 1011 HIO Wn mil lUulon
10 JIg1111 IUI ml lUl anh Io aLn 111)_I ) III li lU It 2) deg wn2SU DD
Irl JIll II IIr II US II
1110(1 lULa lUI IlK) IJ WU
I( llI Htl tNI 1(111 2tlNI HI 0 221) lllil t2S 0 1~ 10 1~13
In (I 2117 I
10U 1l(J ~ 4 _H_j ___
9middotJIlJ5 10115 10 00 lUU5 flUU 4li (tl03 9(11)
leIlKl 1l~)5 lOOU l1KIr JOIS un 003 OIl Ii
34 lECHNlCAL BULLErIN 920 U S DEPT OF AGRICULlURE
COMPARISON OF PHOTOMETRIC A1D MODJIoIED SPENCE-CALDWfLL METHODS OF RUBBER ANALYSIS
Guayule samples were analyzed by the photQ111etIic method and by bull the modified Spenc(gt-Cnldwell mcthod The values in table 7 represhyselltativ(I of typical results indieate It -atisfactory dcglpe of conformshyjty between the two methods in thl range of tiSSlHH with llHHC than OJ) percent of rubbtImiddot On the bnsis of the amounts determimd the results in this runge for the plmiddotts(nt lIlcthod ayernge apploxinHltely j percent highcr
~LAIII~ 7-(oIllJl(i~on of lltlllrIic (IIri mOtllinl SJl(II(r-(ulri-wall IIIrtlwrl~ of rlrrlIIillillfl 11)1)(1 COIIrll of UI(III
1 Flowers frllm amiddotmonth-oltl nursery plants
YAIIIATJO- OF SIli(LE DETEnt1NATIONS Fnoll TnEIIllIEAN
Rllbbel (Uall8i8-Thc plcCision of thc pLcsent method when gunyule tissues Hr( nnnlyz((1 for rubber may be j udg(d flom I Ill datil presentcd in table H TIl(se dahl -how that thl pplCPlltag( uriation of single determinatiom from nwan yullles with low standllrd enolS ranges from less than 1 to 4 p(gtrlent
R(8in~ wWlsi-r-s lndi(a((1 011 page ~j he INntlts s((uled hy the present phoolllttric nsins llHt hod are not tliltly (olllpalable with those of the grtLVimetri( ncetol1l-cxtlt1(tioll II1etho(l Thjs made it necesSllry to selc(t another lalibllltion staudud-tlll Ipsinous exullate from gullyule shrub-thut gies relatively COllstlllt photometric readshyings (table 5) The resin (olltents of guayule roots branchcs or leavcs usually ran(~e from about) to 1-1middot pelcellt The ple(ision of the present methotf WhCll gUHyule thslllS lIe analyzed for reins may be judged from the datalHmiddotpscllted ill table 9 1h(se data show that the p(lcelltage variatiun of sillgle lhmiddott(Lminntions iLO11 meun ynlnes with low standard NTOrs rangcs from about 05 to 4 percent
bull
bull
bull
bull
bull
RAPID PHOTOMETHIC DElEruIINAlION OJ RUBBEH AND HESINS 35
IAIILE 8-luriation inclieute rubller (mallSM of [1wIIle tissue bll thc 1111O0Illclc metwII
Vnrlntlon~Ilbher I (rom mean
ierCtnl Percelll ~OU -22 ~ 25 +27 ~ 20 +18 ~UO -22---------1_______ 51110 0G6 bullbullbullbullbullbull _bullbull
10 ro ----=ii41075 -01 1000 +11 1010 +13
rlln HI itil 1l9~ 1_ ___ =-~~~
115511 ~ US -111 III II 1575 -13 115 b tiS -I a 111 h WlU +22IIM-(middot bull 11K -1Ja Illi c 1000 +03 1J5H1 W +l)7 ll1imiddot tl 1575 -13
Mcnn 15951 131
1102-11 21fJ() +21l102-h _ ~~)SO -17 1102-c bullbull 21CO +21n02middotd ~OIiO -26
2 r~plusmn Il~ 21151 261 I -~-------bull---__ _~~_~______l-___--_
1 lhe$ 1111($ I1n (or SlIlIIllltS Stpnnltplr PHrilClld IIrtlrdlng 10 1hr prollIlIlr( OIiIIiIl(o(I on Imgt$ 4 to IC ~tcond nUlI1 hlr r(J)[ltnts stl1ndnnl llrrot of tilt 1I1(1111
1_1l1~ n-J(lri(iot in relli(Upound rpoundsins (lllalIsfs of VIOJII( lixsue b1 the lhomillric lII(lloli
-- ---~--- - __-------- shybull I I I I Varlgttton
_________~___ ~~lu_n_Jl_Q_~~~_____ ______I__~_o~S_J frOID lDean
Percent Percentgt458-1 ~65 +41IWtl-li 130 -a2Hli8c aliO +26S41i8-d bull 130 -32
1(-011 34I10Olifgt __ bullbull __ ~--====
li-9~2n 881) -06 li-9~2-b Si5 o ~HH2middot(middot S i5 -6$-H2middotd 000 +1
8851 054
O i5 +6 9 i5 +6 950 -20 U75 +6
H-liG3o-n bull -1 n-li6~b bull __ _ -IH-IWH +4H-l61511 bull -1
1tmiddottlU
62~-lI __ 62~-b ij24-( bull OH-Ji
(-Ull
I rll(St oluls nre tor separately ~xlrflCled SllllllllCS IlctOrdlug lO procedure outllned ou pages 4 to 10 i Secoud number r~prtgeulS stulldMd error of lIe menn
36 TECHNICAL BULLETIN 920 t ~ DEPT OF A(]RICCLTCRE
ReUUER A~ALYSrS I~ CRCOE-RcuUER PROOCCTS
Sew rapid photometric m(lthod~fol the ddellllinttion of rubber and reii Hi ill uaYllp ti--ut htp lllell pIPHnl pd oil pag( ~l to In A brief H1111111tlY of It similar rnpid llHthod fm 1I1hb~rllnltlysis of u1lulcanizNl tlIldp lubbll pl(Hlmtlt whielt i~ bn-(tldo on the prill o
ciples dehtilcd tlllLe follows Duplltate nt-gm sllmph of the finely cliyiliNl IlInttlitiup wlirllll out [~ei-()l (all hl lIf((tinmiddotjv INd to lt1iyidl till alllpl) TIll kltolll-olubll portion of till )111(11( tlrc di-olved a- indh-Htpd fot thmiddot lllnkill~ of -tlllHlunlluhhll olutiou Oil Pt 1II hut tIl IUlIp Hn lIn l-fplImiddotd 10 lHI-ml rolllllltti( fln-k antil1ltld(lup to Olllll1l The bnlulUp or till JllO(ldllll i- thatutlilllll on paWs -1- 1 IHI Ii 111( 1(111 1- nIP IXPIP--pd nil til IHi or Iw oligiJla w(lullt of I Ill (I11l1p-I1l11Ilt1 1)(0(11(1
Hupitl PlllimiPJojgtiWllllllllh llIltllOd~ fOJ Ihl llPtlmiddotminntion of ImiddotUlJbll tlnd 1(-illo- ill -111111 Illllph of gutlYllll tiUl IIll dl-eli)ed 111() IlltlY d~o Ill nltlI1lld fOl III Iwl Illhlwl- and l~iJlmiddotb(lLiJlg plant TIllt l[Olllhup hns nlo b(l1l ntuptpl fot IIH lltlIll1illtltioll of lllhbpl ill 11lHhrublwl Pl(Jdlld~ HIIl 1111 hI ndaptld JoJ IIll ann lysis of ynt1J(gt( ic lllbbl[- The llllthmb HIP 1gtn(11 fill tIll fol1owill plimiph- III Grinding
tIll PIOPlly driPl t i~lIl 01 Ul tillg tIll pnHhHt to tll l((lllilllllh~lel of filWlH-- til plllllit qIHlIllilnth( lXIIHtioll 01 IIlbhlI 01 1(--IJl- () llsing oXWllutld olnuh (kttoJls IIt(talp and() fllltil for LIbbel and IH(ltIlIlyptIJllIllIoolYlnJld-o flJllh 101 niJlsl with t(lathelr high IlPililig points 111 to n C) l]olle or in mixt tIll thllt Pll mit tlll rnphllxututioll of luhll(l OJ [middot(ill ill ~() to (l mi1lutp It r(latiwly high 1lllIllllltlltP Ill to 1~11 ) l) lllllipitntillu till luhblI OL Imiddot(ill frolll aliquot () f till oltn ion I IlIlllI-i () f Hlltabhmiddot pl(~(i]litallt (willifhmiddotd lthmwl fOl IIlhlHI Hild llitlifild lllr fOJ JP-illl t~) IIlHkillphotollllliilPIIIIiIlof PlllPlltal of liht tLaIlS mittUl(P lIftlI IlIlbll (II Il in PIlipitalioll 11 II WI( Iplllh thnt (limiJlall till PIIOl dill 10 xtralllOlh (0101 (till dptl1minntinll Iph jill 011 tIll dtwlopllIlJIl of H HIli rOI1ll tlllbidity 111 hpl than I (olot rI
jJlIlpOP-ofallnlyi-I ( p(lllil1thb IIllijOI1ll turbidity or 1llt[lIinmiddotd d(ltl of jgtIp(ii(JlI l)~ lIltlkillU tIl plllltollllmiddottri( ntdillU al tandinu tiJlH~ (dlllilll wlli(h IhlllH(lill-- IP 1llutinmiddotly tnhll) t1ll1t an hlsl~1 oil the (oJlItlIlllItion of IIlhlHI Ill I(ill (lIPIipitat((L
TIll -I(p ill till jll()(Plhul HIP 1-- follOylt (1) 1l~UIIL uJ1lplls of thwl UJfJlllHl (II tliddl(l HUt dlipd 11Illtplial an lXIllltel with11 Ill of till nlnll ill t (oU tlllltIPlll[gtPImiddotatlup oil Iath at 11 Cbull fol 11 minutl I) iIP1lIin(middot(lohd til( (XUtllhllll Jltldl lip to It middotml ynlmlll til( (nlifild by (Illlifllgiuu HlId thlPl IlI nliql1ot of tIl (IalioPlllxUlltl nll Uillltlmiddotll(t to l-llll OIlIIlIllril fiuk- (1) For a trial Ilnditlg 0111 III tlll j liJmiddot~t IllHII IIjI to Ohlllll with lilt Pll shy(ilitnnl a 1(11 it 111 (Dod fill llli lIut ( ptotoJIIltlil IPtlllillg-- of pllllntnl or liuht tlUtllIlillal(I oil n (lpel OphotnJlllllI at rase hng-tlt (If 11 llJ Ill Ol It lollllil1lPtImiddott lloyidld with tIll P10]11 I 1110110shy
Ihlolllltt hmiddot Ii1llI Olllhi lIatioll for -1IpItillg UJlproXilll1l tply Wtl P ]Plwth )0 mp are HHlltk TIll Illldillg lliJtaillld fol tIlt 4-milutl tliall(~ll-
bull
bull
bull
RAPID PHOTO~IETRIC DETERIINATIOX OF R(BBER AXD RESINS 37
ing are referred to a table of equhmiddottllut~ previously p1(pa1elt1 on the
bull basis of 4-minute reac1inJ~ for tilE nmge of lot1telltlatiol1- of rubber or resins to bE elHOlll1t(led tmd gidn thtmiddot -tnnlillfr tillIP fill rUbbEt or resins aiter prE(ipitlltiol1 lwfolE photoIllNliI j(tltlill1 un IUade The r(middotnmining dllplllatt aliquot lll then HHllil up te ol1l1Jle and lpoundadillg ale marle ut the -tandillfr tiUlE iudklltll ill rhl tall1lmiddot for the final r(adillg~ -1) 111( milli1lnm or p(tCPlltllt- of lllhbpL (II 1(-in pr(s(nt are rpadholU a prlpan(l table of lquiltlput for tlll photoshymetric readings h1~l(l ill pnell e1-E on pxpPlilmlItal lhln 1111(1 u-ing as stimtlltlds pure luhbll in 1l1bbtl milllYb aIHI guaYllh ll-ill- lxIHlatt~ in resins detNIl1111lttion I
LlTERATlRE CLTED
(1) lUnSbull 1fl36 THE mURMIXTIOS IIF IOTA RE I III OOl THER llT~II
F1 bullrol IlY U(T1l0fll UfSlfi ~rrnrl r flm lt1 KEYS TI Bill Chern 114 44J-l59 illns
t1 ~ICPHHlObullbull T 1J3bull~ lUTHOO roa THE PtRInCAnu Or a(lIUl IRrIlHU It of TIn
PLRIHEU Htllllflt [ i Bill lallllall 111 Rmiddot 711middotj iIlus
I ) RHBERG P B Ul5 A METHIlO Or ~u(ronrll-nl Hi tIII rUIl[1 f71 ii illlI
bull 14 Hoss W flbull and HARDESTY J O
llH IR1ltDII Of HfITilIZfmiddotR DllIJS ltt 1 Yl fll Off gI bern JIIIlI i ~middotmiddotlf IIl
101 SPEltCE D nnd CuoWELr ~I L 1933 DETER~n-ATIOo OF RtBBER Ii nrllllpoundRBfR Iusr 1uI II1 amI
Em~ifl cttIliIa~~ r Ell i 71middot7i l11 (HI WALTER E D
1U44 ISO~nlS OF PRTlltSrr 1trHpoundV bull l UI n W lHHt (Tnmiddot 1ETS FROM GiYI l~iIl lItr Clttrn SII J UI titJ middotn9--C1 ilIu
17 J YOEbullbullr H lO~( roLORIlETRT 771 IPmiddot nl -W Yurk f H Plrwptric hmica
naly-II rimttry lUll XphHHlnmiddot~ y 1 1
11
HI) ~ fPHELolzTRf 57 111bull Lin xw Yk t H lt PhmeHt CblUlmiddot ila AnaiY~l~-(H lithrry and XIhmiddotILpfIY Y wirh enomiddot rrJlllrjr hy H KtlJnJU11 I
t~1I --- and ~ARVER L 1f41 nlua-w ~in L liLhr IS IP ll~ XIW Yrk
bull For-sale by th~ ~a~fr1nt~nf1ent Dt~c~~ogtnts-~ s t1i rArnn~ut Pn~~~ tJffieshy
Washington 5 D C bull Pl lU ~nts
100
22 TECHNICAL BULLErIN 920 U S DEP1
90 bull eo
I shyz 70LLI 0 a LLI a 60
LLI 0 50 z
a ENTIRE 2-MONTH-OLD PLANTS~ 40 b ROOTS AND BRANCHES OF ~ 3-TO 4-YEAR-OLD PLANTSen z WITH LEAVES REMOVED ex 30 a C CURRENT-SEASON GROWTH OF l- )-TO 4-YEAR-OLD PLANTS
20 WITH LEAVES REMOVED
d LEAVES FROM 3-TO 4-VEAR-OLD PLANTS
10 A
0
a Cd 100
b bull
10
80
I-Z 70LLI 0 a LLI 60a
LLI 0 50 z ex I shy 40 ~ en z ltI 30 a I shy
20
10 B
o~__~__~__~~--~--~--~--~----~--~--~ bull350 400 450 500 550 600 650 700 750 BOO 850
WAVE LENGTH lM~)
FJGcm O-Sll((middotlllll tramaniW1IHl (mrpS f(JI (xlmll 11011 n J1ll of jlta)nle tissur ill n 2--m1 Y011111P of (A) Illrthyl ji1I1J1ltsl krtonp 1111(1 (ll) nt(middottQnyla(umiddot tClIc-C(l1osuln a-i
bull
bull
bull
RAPID PHOTOlIElRIC DETEH-UXATroX OF ntBHEIl AXD HEstxs 23
ThE dula Pl(S(l1t(lltl indi(ntp Ihut 101 Illp ulimls llHthyl liohutyl htOlIl (lxtrHts (lI(I r(dolls of Il1Hxi11111III nigtol]gttioll wiH1I all (is-lIb 11 cOllsic1(]((l n1( blhn(11 wn ( ItIl( Its lIO to () I1It~ nlid Ii to Iii mJL
WhllNIS tlw I(gions of 1middottnL(s( light 1lnlllittamp al(l lgtPlW(PIl wan Ipllgtltsnr) to Ii nllt jW) 1I1JL nlld alio Silllill1l 111l1b (n SI(lIlId 101 nc(ton ]altmiddot(fmiddotollp-(llloolp ~ pxt Ill of 11a 1111 t illl TIl( (1101 du( to lolo ill tlw litlltitl a 1Il1 lullll(I tH lPill- hanmiddot bpllI PI(_ ipitated ma he 1((I1((d to fltI ynbhing poillt II ph( illg OJ illshylmiddotJall(( WIWp balld nhm ()) IIIJ1bullbull[1I111 lxjlPIitllll1b Illln -h()1 that Ih( lIIot uilahl( WHYI lHlIJ fOI 1-1 ill 1l11J1l(I HIH11Pill- illllllrsi i-in till IlPighl)()lllll()(l of ~llIl1lt bull
bull UIlIilHlIy of n typhn] lXPllillllllt to )10 l1iP(tiP ((JIlllo( of (ItOIS dul to lOIOl in 1llblnI Hnd Iill xtnumiddott 11(11 IIIIolp t jUl i p1llelll((l ill tub]lL Till llhlllt- 1tpIO]II Hnd ((llll~()h whit-h UI(I ](]Hllilltl n 1I01lllIhb1 01(111 lxt 11111 IIll 1llll)1 nmtp[in I and )(middotills Tid IIlnkl it poiblp nftlI tlIp uplll1tillll or tlll o1PIl( (0 [niH lip 1Iidl1p~ of lI111 11111(( ill lit ll11l1)[1 (llnlIb nlld Ihll
Sl(ll n ol1lliOI with tllP olnl IJllt illiollt HIl Iltlllll llllI (Ill ltllthpl prpipitnnt j Ihll1 nddld OUI ha a lIilPt lP( of till lIiciPlw of WH( lllIgth 7) lUI- ill llilllillatiu (nnl till tll Ixtll1I101l ()lll~
Tuu tmiddot-Elilll IJl flrldillY 11-1111 lrlllI IjfJI til islII 1 1(1 ([rllt IIIIIJIlIr JiIlIt~ if 1Il( Ihll 111111 k til I III Ilrln I 1Intd tf 11111 JiSf fill I I II I tIII Ilf Iilltl 1f1JlIIillII1f I Till 1[ 1 IId 1 (I (middotIt 11111 (I1I1iI1 1lf1IWtlfJlIIllfflr p middottrllhIJ11 II J III 7IImiddotIa 111 111 lilt jJIp 111 wilTII
t~t tnVIli~ ~nn r kn t~ i tmiddot ~~l Jr 1middotmt ltlTt
HmiddotOtt ~I~ lin t I ~ 1 t~~l ~qrmiddotthtmiddotrtwb
Hult-middottltlru t T Hw ullut rHtt~ r II I ~ PH~lllt
A~tmiddottHHjmiddott~rjd rl ~gtllh 1 tn~th~ ~ ~ middotI lt~ b w bull hmiddotth~ 1i~lIhun 1 Ii tnl Illd1 -11lt1(11i lullI lUI tJl ll~ t1~11n( I Ihan1li flfttIJir Ult I Uuhtltt ahuul l(hmiddottHmiddot~t trv r fti HIt lftbyl tlonhUt)1 k_hIl( 2 m~ fmiddotf tuhlHmiddotr In mlth~ llmiddotlf- 1 t r
t r_~ t j
Arhlitlltd ~llIIDHl NcWitn1 ( Ar-(lt()nc~middotttrrtrt ritJJI~ -Iu nllJtl4-middotr
ACtmiddottflnp fmiddotxtrn( ~ T-P511ftf tn mtmiddotth~ 1 ~difmiddotut~ kdn 2 nltt ulruhhtr in Un-tIl lltbu )J~IYt
rUth(Hl~hltlft HhubU
Illlh(I(t tttUtUt hUbtl til J ~jlitl(J Hilllll trtIIImiddotjtl1ll
(UShl I ~tlO wHllolH rulh r (middot1111$0]( J~rru t t )lthyl 15bullbull1middot1101 klll1l
Ili( UHUicbcul ~((i1rUtl ~ulu1iin 1middot lIUIll Ilti lrllltlllt I Ruhhr llt1thuI r1 -1 Irld
ltlt1111Sh 2 nuz f)rruhl~rm nlith~l tu- h f nt nil~middothgt(H] tlrlftmiddot 9lUtirtl middot1 1
rlcltfl( H(l dnllltml it
(IISllhH~rI( Iultruhtr CII05 1v ltTlft I 2 UI~r ublwr In llldh I hlt~1 11) lgtjdvr(llsl~9rlltmiddot middotlmin ~ I~ gt AIHItilltl no IrttipHallr iI
~ Bbnk 10ol m(thyl i~tmiddotut~i kdHn H 1 m1 j~~ l1rH-t lt~tlfltmiddotn sf n it ll HltlMjftr~nol O2~mlJ ~U~1o-ulp ti~tW -xtra~middotl(lt1 ltt 411 ml bull ie f Ct- kft rt t~ tirattJ middott ill r u l1kn ttJt
in metltl isobutyl kNqnf nn~i mljp ur tmiddotmiddot ~oml ~urr tttl i t w ltJj1JH kt 4t 3 nlank 1 mL((l1t~rthmiddot(middot mI mttr~ ~but a kmiddot tmiddotc d 11 ~ gtli~b~ hifIAft- fl~ lL lnti 149
ml8(dlfilll BO bull 02 gm guayule U$Stl(middot xUlClt-l tf(h tft wI n nmiddotmiddotmiddotlgt 1 lznt on tmiddot ~Jt r~1 ~~u~~ H~ iI~ thT
24 l$CHNlQAL BULLETlN l20l S DJltJPT OF AGHl(CLlOHJltJ
In table a is pl(sentc(l such c1il((t edlt1tIHC showing that thc (0101 Ixtrnetccl from guaYIIle tisslIe wit h II(P(OIl( n nd (pl1oso[yc is cll(div(ly sCIe(nec1 out by the s(lp(tion or wnw length )0 miL Oil t1w SI)((IOshyphotonwtpl This tnb]p all-HI ihos thai thl Juhlwl altl(l((1 (nn IJl quall shytitntivcly 1(I(()(Ipltl in tIlt PI(ilIH( or Ih (o]OIplnwPIials and Illsins and tlmt Iuhb(l WtlS nppnlllltly 1I0t (xtltI(((1 110111 11l glll1I1l lisslIt b~ tlHSP SOhlllts Thls( ((suIts ginmiddot (OliIHillg (idJt(( that t Iw IISI of waYl llngth i)ll 1Il) OIl till SppdTophot OIllltPI ii t hl 1101(1 p(oshy(ellule in photolllliTie IlIlalysis of luhhlI OJ l(sin-
SELEGTIO- OF )IOiOCUHO)IAIIC ItIIm ((1111110
On th( basis of th( IPHIlb shoWIl in tabl(l 1 al hlllpls (1( IIln(lp to SPCtl lC the PIO]Wl 11101lO(lIOl1ln til Ii ltlJ ((lIllIJi nIl ions 10 llIiOlS (oIOlimet(Is 111(gt 7W-Ill~ filtpl flllnhwd 101 til( I1~lI1l photoshyplpct1i( (o]oriJl1ltll fol which Ill( (hlll(IlIiitit~ oj t hl Ilda he light ilUIlBlIIhiSioll (t) elll nn -hO11 ill fig1lle 10 iws satlsfa(lolY IPshysultl 111( iiO-mL HitlI olllhintioll 101 whkh ttp (middotIatinmiddot light tlnnsmission (ullmiddotis a 1-0 showlI ill figllll (I is -nthdnlto1 hut this is not stnlHlnld NtllipmPlli
Up to fhl PlPHllt lIS(middotflll pound11((1 (ulllbinntions jn lltl iOO-I11L Iunge hayc nol bllll SlClIlld 101 lhp Klpt 1-1I1l1I11PISOIl (olOlinwtll bu fnltlwl nttCl1lpti 1( )(illg IlIHd
TJIpound OF ST~lmW AFTEH HIIJ1EII Oil HHSIS rlll~CIIITTI(J
~ considl1ltiol1 of ttp lillll of Inlllling af((1 plpeipital ion of 111gt)(1
01 l(sinSTlOIll ollltionis impoltant J(jl~ thC1HI(Plltngp of light IInIlSshy
11 rshy10 f shy
09 f shy ~750 Mil- DOMINANTI
~ 08 cshy I WAVE LENGTH z
I III III i O7 - I III
~06 - 05 shyw
a
Igti= 04 - 720 Mp DOMINANT ct WAVE LENGTH- ~ 03shy
02 f shy
01 t shy 1)O~~~gt~- J 600 700 800 900
WAVE LENGTH (Mp
bull
bull
bullFIGlRt IO- COJllPIUlItiw ~IW(middottltll tlnIlRlllii-lion (II (IllP( 101 1i11(1 olllhinulloll
with dominllnl Il(lllllgths at 720 and 7iO lUi
bull
bull
bull
HAPlD PHQTQlfE1IUC JjETER~lINATION OF Rnmrm AND HEtiINi 25
mitted (spertrophotoll1eleL lCuding-) Ol light (1 (tClcrl (phOlOshyJluol01l1et(L lcndillg~) i~ StlhjNl to (hangl
]fjt~l1le 11 and l~ show that ill til( (asc ot tJaugtIllitteltllight llJHC th~ (x[llliHlllIlnl (oIHlitiOllS tllpl j lilst n dtlln-e ill Pll~(lltngl or UllllslllittnlH( follrnY(l by It ptJiml of lClntin stability with only sliuht (1111 tHn- a f(Pl a lIt1ll1btJ of minutes The light t UIllllitblllll t l(1 ill(Iln~(s This lIIay IJP llllllJltlli7P(ll1 ffl II ow 1Ilt )( f(( darI oliIII tIIlIlNlIlitt(IIIlfJIIlh (iditilIiid Ilil1 pllIipintnl )uoshyIn Of ( 8inx in (~f1( I~iUII i~ Ild stahl I 11 itlll If 1inl nh prlshyilli(ioll of 11l1d(1 II IJIX f) jllIli II (fJJltfiIIlilty slllMI IIriot 1) IIIPldUnl1i tll(I1I rllltltilJl oj tJi~ Jlt jiot IUN ilUf Jxl1 will tIt( tOWI IItlllilil I 1llIlllblJIol I ill I~11l11111 d ill till ifjuids JjOI scnttplltl light 011 till phololltHJIOIl1lttl till dilPCt ion 01 elangl b tlw IPrfIi (If that illrli(atPll rOl tlulll1Jittp(lliuht It Itlll b( llluliJr I-(Pll that if l(middotndlnJ- IIIP mad n itl I t lIP ~()ll1d()lb lpalll this pllioJ of nmiddotlatirp tuigtility tllP llLot tIOllt thi Olll(P (nil bl IPdUCld to tIl lltini III 11 Ill TIll l~adiltg (illH~ bbll Oil tlHl datn rUl lublwls and llsinlt Illl ginll ill tnhh
50 r----------------------------------------------- f shyZ
~ 40 ~----~W~A~V~E~LE~N~G~T~H~7~5~0~M~P~~~~ ~ --------------------=-=-= ~ 30 f- WAVE LENGTH 540 M~ _z _____ ___ -=- __ _ ~ ------shyt ~_=---=-=--I GUAYULEIII 20 -Z HEVEA ltt II KOK-SAGHYZ f shy
4 6 8 10 12 14 (6 18 20 22 24 26 28 30 STANDING TIME (MINUTES)
FIlirtn 11 Emmiddot of wav hll~rh Il li~ltr tlall~lIIit1alHl aftI IUIlItHt -Imlli lug 111m for guaynh llmiddotn 011111 middotiolIlJh~z 1111111 llijlitul1 flolll 1lHlh~ll1Jllryl k11II11l ~(lilltlll h~ lwitlitll 111Inu1 111l~1It1 2)1111 o1U11111 (Helillins on (illllun tlunhll IlIIJlllw]ntllW111 lutl(I[lholtllllltlt with ijUjt Wlnl IHI Ilf1 I
11 EFFEGT OF Hbli 1 -()JXT10~
Tilt lnblwl ~()h(llh pxtnl( till IPillgt ubo It 1m nllu1- bellt -~atea thut ~lll 11-111- tUP olnbhmiddot ill middottIIlIlOl ~1It tlWIIJI( my U)t PIl (tlIHatcl WIth tl1l lullh(t I tahle lJ 1hln 1- -1111 tIll (llllstlOll of nny p()~iblt tITptt of XtIIl11 diflp]lws ill ((JlllPllttUliollS of 1l-in lil lolutioll alollJ with till 1lIltbpl TIU data ill wbh +ho on tIl( hn~is of (olorilllPill ladillU thaI tll( IIUOIl1t of lnbbll Plllipirntld 110111 Ilwthyl olnlld kptOlll olntioll IJ 1li-jHlllnt 1l)04 in 1-llltlIllt ethallol)- not amlll hy thl llllNlI(l of llvin aU1ouut of llins inolution bull
-----
26 rECHNICAL BULLEfiN 920 U S DEPl OF AGRICULlUHE
100
90
80(I) C)
z Ci 70 UI a 0 60 a ~ UI ~ 500 ~ 0 I Il 40
30
A 20
0
100
90
(I) 80 C)
z Ci 70 UI a 0
60a ~ UI E 0 50 ~ 0 I Il
4-0
30
B 20
0
--
--shy ---shy---
2 4 6 6 10 12 14 16
---shy= ~ ~ shy
-
2
025 05
10
15
20
25 -30
35 40
SO
-60
=70 80
16 20 2224 26 26 30
OS
- 10
IS
20
2S
30
35 40
-50
-60 -70 -80
bull MGPE 25-ML
VOLUME
bull
MGPER 25-ML VOLUME
Florm 12-EtTld (If till1l or Slllldill~ 011 light transmittallce (01 (A) gUllyulc lnUIl(I plccipitllitd frOIll llltt h~l isobutyl Ielollt solution Ily neidilic(l ethanul bull null (B) gUllyule ll~illii pre(ipitated flom aeltoll~lllcetOlll-Cl])osolY( 3-7 solushy11011 by H(illilip(i l1U (HPlldillg~ nt -lIlillult Ifllpluls 011 Evelyn photoelectric colorimellr with jU-lllp tlllll alit U-1I11 npN(lle spp also table 2)
bull
bull
RAPID PI-IOlOMEllUC DElEnMINAlION OF RUBBER AND RESINS 27
TADIbullbull ] 4-ReZation of amiddotmount of middottbber pleeipitate(Z Oln metltlIL isobutyl ketone 80lutions by OS-pereent H 2SO in 95-pere(lIIt ethanol to umollnt of resin8 udde(l U8 indivute(Z by colorimetrio readinU8
(Rubber ami resins cnlculntcd on bnsis of amounts in 5middotml ullquuts of extract from 02 gm of tissue in a 2fllll olumo( bull
Hubucl r~cocrell whcll rcsins nddcd as IndIcated Htbbor al1dcd (pllcollt) ---shy
__________bull_________ ~_12rpcrc~15011crccllt 7511crccnt IOOpcrcent
PerCtllt ercellt Percellt Percellt Percent o o o o o) 50 250 263 252 25000 500 500 500 500 700 750 750 751 749
1200 1250 1250 1250 1250
EXTRACTION TEMPEHATURE AND TIME
Typical experiments to detllmine the time required to secure maxishymum extmction of rubber und ltsills at 115deg U Ilre sUlIlmarized in figule 13 the solvents used-methyl isobutyl ketone for rubber anrl Ilcetonylacetone-cellosolve 3-7 for resins extraction-are very eflicicnt since under the conditions indicttted maximum values were secured after 30 minutes of ext1llction The most eflicient liquid for the bath (lig 1) used in extrtlcting rubber or resins is ~ high-grade cylinder oil (S A E ~O) The sand bath and such liquids as glycerol have proved unsatisfactory
RUBBER AND RESINS STANDARDS
According to the National BULeau of Standards 1-_ lhclc Is no gellcrnlly recoglllz(d standard lIIutcrlul [ior II rubber standard] The rubber hydroCllrbon ill llifferent samples of conmlcrciul smoked sheet or pale crepe from heclI pluntlltions nries from l~ 10 04 llercent of the totul nutletmiddot the most 11Ioruble conditions Of preparation
McPherson () has described a procedure for the pLeparation of pure heve~ (Hevea brasiliensis (H B K) MueH Arg) rubber from crude rubber or latex In the absence howevcr of ~ generally recogshyn12ed stalldard for rubber hydlQcllrbon [caoutchouc (CnHUs) xJ the standard adopted was that of the relnthely pure product secured from gunyule tissue txtractiotl nccording to the Spence-CaldweU method (5) or the motlified PIOCCdUlU of Hohnes lind Haasis (p 2) The details for constructing the calibration CULes are given on page 10 Standard rubber samples apparenl-]y can be stored for a long timc under the conditions des(libed on page 10 The duplicate colorimetric lendings for glULyule rubber newly extracted by the modified SpenceshyCaldwell method were ()J2 ench as compared with US) each for the sample extracted by the same method but stored 1 years In each case colorimeter rcadinllS were made on mixtures containing 2 mg of rubber in It 25-1111 Yolume
The selection of tt suitable standurd for guayule resins presents some dilliculties Tll(~ acetone extract of gUllyult estimated on (l gravishymetric busis~ for instance proved to be variable depending on the type of tissue sampled or season of sumpling because such fractions as
COllllllunlcntion dul(lt1 Octohtr 22 11H3
28 QECHNICAL BULLEQIN 920 U S DEPT OF AGRICTTIIlURE
16~==========================115 shy
14 bulli= 13 z ~ 12
ffi II Q
10 c w 9a w
8gto () 7w a
6a w
5en III ) 4 a
3
2
A 00 5 10 20 30 60 90
14~------------------------------------------- bull13
i= 12 z w II ()
a 10 w Q
9 c w 8 a w 7gt o () 6 w a 5 If)
z 4 If)
w 3 a
2
o+B~~__~__~____________~__________~ 5 10 20 30 60 90
HEATING TIME (111 NUTES)
lllGUltE 13-lDffect of time o( lICntillg O2-gm samples of gunynle tissue with solYlIt nt llfio C on lo(OVl)ry of lllhlJer alld 1Isim Lt HlIhblL extracted with methyl isohntyllwtone B resins Cxtll1cted with aCftonyla(etonc-cellosolve 3-7 bull
chlorophyll are weighed along with the resins in the acetone extruct but are not estimated by the present photometric method (fig 0) 1he use of a diffeJent stanclttrd waS therefore indicated
bull
bull
bull
RAPID PHOTOMETRIC DETERMINATION OF HUBBIm AND HESINS 29
The resins standard selected is based on n relatively pure source of resins the rcsinous exudnte 011 the stems of guuyule plants IJldimishynary expeliments with the resi nouS cxuclate from diffcrellt gllayu Ie strains of various ages indicatc nHlt there is little YaLiation in this subshystance on the basis of Colorimct(r readings 011 2-mg aliqllots of 01shypercent solution in It 2i-ml volume (tabl( li) Expelilll(lnts have shown that the air-dried (xuclate contains 3RtOH p(Ic(nt of -volatile matter This material is l(latiyt~ly stablp ill (OlllpoBition and is npshypurpntly on ly slight ly hygroBcopic as shoWIl ill Ia bl(1 1 Tlrp Ipsinolls exudate may be jJleplpd in two wayi-i fl liSP as a stallClHld-(l) the clpan exudate is clripd iol Ghouls at ()1deg C at W indlPs of a(lIum Hnd aftclbCinOglOund ill a molfalis 1)I(spI((I intn airtight COllilinel OL
(2) tllP Cx7lclate is clissolllt1 ill a(lhllll and filtplpd PlactieaJlyall of the acetm1l is thpn lYapolntwl olt OPI a stlam or atCt hath and Ow residue is dripd ground an(( PI(sPIld as ill tllp fin lllethocl Tlwse two prepalHtlolls a1( (ompalpd in ta hlp ) 111( (((tails fOl ~t()lil1g the resins standald and (onstlllcting the calibration CUITPS alc given Oil page ]2
lAIIIg fi-CUIIIllrsoi (lJ lIr-dr(1I IIIIi 1((11 II II-()I-tr((l l(sil~ 11111111(8 of I II 1111Ie
[Colorimetric rrndill~s 011 1~I11 phulll(Iclrie eolorillJct[lr with i~()middotmll (100- to iiOIIIIl) fillcr [lnd 5-1111 lIperture preeipitantl part ofO5middotPIrctllt 10 to 5 paris of IIOj
nupliclllc(oloritwt([
nIl(lin~s (hIlSlcAg~ ofSlmillXo JrNliltlCllt of fPsiJI$ L1Xtlrlntp on 2 IIIg ofplanls fllsins (XIHIIlt~Jwr 25-1111 vol
tII1(1) 1
leflTs Various _ bull ____ bullbullbullbull 3-9 Colll)Josiltrlairmiddotltlricfl bullbullbull nf)2 002
])0____ bullbullbull _bull __ _ bullbull ~-l Composilld (ri d at n5 C in aUmiddotimh lWUUllJ for l (jOuj(ja hours])0______ bullbullbull __ bull ___ bull 3-0 COJIlpositld disso]NI in neptolll f1l1erNl fl(lf()ll( GGO i(jO (Ivaporntld olT OV(1r Stpl1l11 halh TesidlH drl(ld I1t fi5deg ( ill anmiddotinch VIl(Unlll for 0 houlS bull
middot106 __ bullbull _ Jir~c1rild_~_~_ _~_ ~_~ _ ~ ____ _ __ _ OUu GOifina_~ ~ _ ~~_~ ___ _ _fln~ ~~ ~ ___ ~ __ 6(imiddotI tiliA H)[_ ltlu bullbull i18 tisSflOabullbullbullbull__ bullbullbullbullbullbullbullbull lt10bullbullbull _ tillO llitO406__ bullbull __ bullbull __ bull __ __ lt10_ Utl2 fon591_ fo__ bull liGa oOa 406bullbull _ __ lt10bullbullbull_ li5S OM
j Ph( vnluls in Uw Inst COIUIIlIl indieatp thnt gunyulp fesinous (IIHlnt( wlwtlwr dfircl hi Yn(tlLJ1l1 wilh L~ perc(nt loss of volntllt wutl pr or tWl c1rild giVPd npproxil1lnh1ly t Iw snllw colorinwtCr rNHiing- 011 till busis of aliquot~ cOlllniuiug 2 IJI~ of flsillS lXIHlntp l)tIf 25-mI volultl( Ihil- illdicate~ thl11 Uw UITW IJ1flS~ of olnshytile mntl(f prt~(iJlitnt(d gins npproxilllntlly Uw $1II1l (oiOfirnl1tlf ftudiTlJs ns tho ftsidtw A pnlill1jllaf~middot (XIlltrinllnt indicutls thlli th VUllltill muller l(lIlSists of thl Ilrplne oil fmcl ion I5-(1Il gtnplls or rlsitlOtlS (lxudntll gnvll by stPll1U distillation nn Uefllgl of 011111 of jl(lfPlIW oil with npproximHte tilllsity (If OHIi lind lhus rrprlsll1ll( IlPIJroximllt(I~ 01 Jerccllt Of t he original weight 1hls lllrClnlage complrcs wllh 38 llltrC(ntlost by drvinI( in IICllnllJ
aSplusmnUH perceilt or orlginlll weightlosl
The wailnble illfolJllntioll on tlH (ow-JitlPllts of the gunYllle r(~shyillOllS exudate alld tl1( HeetOlIP ext act of gaylp ti~slw is sllIllmarized in this paragraph lYalttI (u) alld also Hangcn-Slllit lind his coworkshyers 16 reported that 20 percent of the resinolls exudate from gUltyulc stems is parthenyl cinnamaie (CHuOH=CHC020 11JI2r) Steam disshy
15 (OIlIJIIIIUicatioll flom A T Haai(II~l11it llId (0011(11 Calif0111 ill Tnfiitnte of Tccllllology Past(IlIJI Jhps( wOlken al Htud~ing the COTlHlitlllllts of the acetone extract and other conlltituellis of guuyule
30 TECHNICAL BULLETIN 920 U S DEPT OF AGRICULTURE
tillation of similar resinous exudate in the writers laborntory has yielded approximately 4 percent of the whole as the telmiddotpene oir fracshytion Haagen-Smit and his eoorktrs nportec1 thttt about 25 percent of the acetone extract from guayule branches is parthenyl cinnamate and 6 percent of the bark (ltortpamp-phlotm) extraet is parthenyl cinshynamate These workers fm-thcI reported that 25 lwletnt of the nc(shytone extract frolll bLllllches is a compound with the tlI1pilicaL formula CBoH400a 1 percent is a compound llwltillg at 2P to 2T5deg C and 1 percent of the extract from the ]eav(s is tl (olllpoulld nwlting at 100
to 1710 1Valtei (6) reported that 3 to -l perc(nt of the tI(eton( txtract
of leaves and flowering StPIllS of guayulc eonsists of waxlike substances soluble in olgallic soln~nts but insoluble in at(l and (on(ent1llted H 2S04 The flactions mentioned on the basis of (onHLTutle esti shymates of amoullts actually isolated tlecoullted for about H ptIcent of the totalncetollt~ so]ubles extracttd from tll( guuYllle 11 rub The other constituents ltlilaill to be i(](ntifi(d
RUBBER AND RESINS CALIBHATION CVHES
Typical culibndioll Clllves iol Iuhbpl and I(sins bas(d 011 (ldtLminttshytions made nccoLdillg to the plocCdmC outlin(d 011 pages middotb to 1G arc shown in figulPS 5 and 1+ The spCdlopliotoll1lttL en (OIOIjlllctCI readings are plottCd on s(lIlilogalitllllliC pappi ag-ail1st (Il 11IbblI (011shy
100 ~ 90
80 ~ 70 ~
z 1amp1 0 II 1amp1 IL
1amp1 0 Z
60
50
40 ~ltI 30 ~ en z ~ ltI II ~ 20 C) ~ oJ
10 o 2 3 4 5 6 7 8 9 10
RU8BER IN 25-ML VOLUME (MG)
bull
bull
bull FI(lURE 14--Ctlihration curve fotmiddot gllftYlIlc lubb01 (Hct(lings Oil COIPIIHlII tlOl1hl(
monochromator SlCClrophotolllet(r with 7fiO-11IL Illtel alld Hllp Wll ( IHlll()
bull
bull
bull
RAPID PHOTOMETRIC DETE~MINATION OF RUBBER AND RESINS 3]
centrations From a casual inspection of these CUlTes it would appeltr that Beers law does not hold Actual tests indicitted that Beers law was applicable only within a narrow range in the upper portion of the curves The analyticlil results on the basis of photornetric readings nre therefore calculated by direct reference to calibration curves or from reference tables of equivalent values bllscd on the cnlibllltion curves
Calibration curves for kok-saghyz alld heyea lI11tulltl rubbers and Buna S (GR-S Chem Gum IV Goodyear) and butyl (GR-I Standshyard Oil Co Protoc) sYJlthetic rubbers are hOWllil1 figure 15 The samples of kok-saghyz rubber were furnished by the Diyision of Rubshy
100
90 ~I) ()
z 0
1amp1 a
~ a
80
70
60
s 1amp1 ~ ~ 0 ~ KOj-SAGHYZ 0 l Il
50
HEVEA~ ~
40
100
90
~ 0 80z Q 70a Co)
a 60 ~ 0 0 x 50Il
40 ~----~~----~------~------~------~--~ o 2 3 4 5
RUBBER IN 25-ML VOLUME(MG)
FmUIlE 15-CaJiblation curves fOl kok-snghyz h(YCII Bunn S lind butyl rubb~ls (Readings on gy((yn photoelectric colorimeter with i20-lIIp filtpl and 6-ml aperture)
32 TECHNICAl BUIJLETIN [)20) 1 S DEP1 OF AGrnCUIlfURE
Iwt Plant JIl(I~t ignlioll of thi BlII(un and (1( l))(parcd according to 11( SPltI1((-Culd (]] (6) PIO(((lllll Hlpt pal( CLPPe was (xtmch(L with acetone blI()Ieit W 1I(gt(11l a ttnlldal(l
SEXSlllVllY Ol~ llETJIonS
By lip pIO((l(II11P olltlillP(l 011 ]Hlg( +n Iowa (lOOl IIIg (11 1111i(l0shygmm (gHlllllla) of 1hblI ill a 2)1111 yoltll1ll (all )(gt dltpltld Oil tltl Col(man (lohlP mOIlWhlOl1lHlOl l-I)((t 101 l1lOt 0111 ci( I ill1ilnlly 001 mg of Iublwr ill a 2J-1ll1 n]ulllP Illay bl Ilad Oil till EnI)1I photoshyllectlie (O]oLillllt(I Thll ya lllll- 011 tilt IHl-i- (J I (xl ad iOI1 fmlll 02 gill of til-lI tH(JI(lillg to tllP -lllndal(l jll()(pdull 1(PIPStlIt IlO()2J tlnd 002) P(IT(lIt of llIbl1ll IPI)(((inly bull1t1lollgh -lI1t low allils can be d((d(middot(1 il lIoullt1 Ill IPtllizpd thnt till PIIOl ill PlI(Plltng( or tll( al110unt dltlIllIilll(J i ltlatlpl high ill tili PIY lo Itlllgl 111 aetllllllladie(middot Ill( lopl lillliL 111)(1(1 lIw (ollllil ions of tlil ]lI()(lltlIIIl u ol1tlinpd ipt at l11 11I1 or 1111gt11(1 illt i-1ll1 Ollllll IlPIPltPlltillg 01 p(gtl(pnt of JllUiJtL un tlll 1Hli or (xlla ion rlOI11 II rlll of tisSIll
EIlIlOH COSIIlIHIIO
In Oldpl to H(IIp ill )1lHtPltt pl((iioll illlpIi1I- it i lH((SSHI to slnlldHIdiz(i rigidly 111( Pl()((dlll( 0 illdi(ntpd Oil pnglt- - to J( If lids i dOlH tlip lXIHlinwnlal PIIll is t(middotdllld 10 n ndninlllill
Illlt pl(iioll of (hI ]lIPPllt 1IHllwd Oil til basi of ]llllP llIllJt1 alld Ipsinssollltions call hI jlldgl(J 110111 figllll Hi lileh lio- til HPIlIgl d(intioll oft -illgIP lI1lnSIlIlIIIlnt in lHi((lltagl of Ill( alllOllllt 01 Illhshy1)() 01 lpsins d((PI1I1 iJlld TIl( (1101 PlI(Plltaglt H1( gi (1 101 OJ) to
RUBBER IN 25-ML VOLUMEMG) 004 01 02 03 04
i= I I IZCtOW
fbA ICtU CtCt WW a
01 02 03 04 05 06 07 08 09 100 = RUBBER (PERCENT)
RUBBER IN 25-ML VOLUME (MG) 10 20 30
~ I CtZ
bBOw Ctu CtCt Ww o I~
010 50 100 150 200 250 RUBBER (PERCENT)
RESINS IN 25-ML VOLUME(MG) 10__ __3-0_ 40 50 60 70 60 90 100--_-- 2_-0
Ct~ -r- 1 I OZ
WCt UCt b C wCtW
a o I I 150 250
RESINS (PERCENT) o 10 50 100 200
bllI 1tI W-Yllnl dtd1 ioll I I 11l1 11IlI11 1(111(11 1 III Plll- IlIIIlol1 01 IIim~
bull
bull
bull solution Il basis J o golH of tiSSII (JlILCl-nt (11(11) for (~I) (l)1 til O 1I1
of luhllpl lin 1 III I (I Ill of lUhlJPl nllll laquo I J to 111 nlg of IlSlllgt (Itllillgs on ]iYllyu pllolwh-llrk CO[IJlilll(-(PI with nOHIP Iiltlr lIntl U-lIll allcrture)
RAPID PHOTOlJElRIC DELEHlllNAllON Cn HUBBER AND H1~SINS 33
10 mg of rubber anel1 to 10 mg of resins in a gJ-m1 yolumC For
bull
bull
bull
comparative ptuposes the leslllts arc also calculated on the basis oJvershycentage rubber OL tltsills in 02 gllI of tissul As WOlllL be expcet(d the error increases sOIlHgthlf for 1(lali nmiddotly low COlHell t1llf iOlls oj rllbbeL or resins The curves in figure 1(j s1l0 that ill til(gt Illlge Ol to 10 pCrshyeent of lubber the elTOI rangts Jroll1 abollt Ll to II) ]IlC(lIt abo(~ this mlllc tIlt (ITOl d(((ts(s to (ollsidlItbly ltmiddotss (han 1 1lICPllt of tlH mllollnt ltl((Lmill(d Hil1lilally in tlH (lISl of l(sins analysis (fig 10) the ltLTor is (onsit1eIubly INS than 1 PlLllnt ill (he lallgp of 11 t~) ~() penPII t
In nil ([lSl of lllhblI alld (sins lx(Inltpd tIOIl1 (issups Ol addcltl to tisslle lxtlads (s(( tabhmiddots (i H) illyolillg ll01P o(lllntiolls the eLI01
is hig]wl thun that indilHtld in figllll ((j Im pUIl Ill )])p I tllllllsins solutlOII
COlllUCIIOXFOH IXSOLl-IlLl~ Ilgsqgt(Jg
111 th( Jllo(pdulP ollllillPd 011 paw I till illsolllhll isSII Ipidll( tflpl (xttlw(ioll is (Ptill tlw lIask l(lll till xtlct i l1wdp up to yoltlllH It is not rOllPllipnt (0 IPt()PI qWlIltitati(Ir III(lw[olH a 11(1 pllooll extlnlfs of guuyull I is-lll alll thl1l main t11l111 up (0 YOIUllllmiddot bpCaUHI sllch all additiollal stltp wottld]) tillll-C(JllS11ll1illg Th( Iogiea nll(gtIshynntin is to mnkp tltl lXtlUCt Llld Ipsidup lip to OllillH in till original flask andi llPSStllY 10 llwlno tl OIIpdioll wlHIl (allIlnting [hc llshy
Hults f(JI [hl oll111lC displupd hy till ins()lllbh llsidll( III it l)picat (IXpednHllt (ollsisting of Jhp lppJiea(iolls if was Iollnd llftt at ~iiO ( 02 gill 01 Iuhhll pillS IPill-fl(( lisslI(gt (lollpdll fot llwistUlC ou basis of dlyillp ut lOW 101 ) llOlll-j (lbp(ld only t~ llllUll voiul11P of OOk7D~- OO(lOO(i Ill of lllthyl bolnl(yl 1lIOll( (lplhlli(al-t(Tnltle sp gl () Ii I ll(Hli (j at ~)) -gtitllP tl1(gt 1It101111( () r t is-lIl xt Iadld j sl1lall til( PlIOI dul to Ill(gt insoll1blp Ip~idll is slllall III [0111 ill( wOtk it (all lJp diIpgal(ll(l
]hcon~lIY OF HllIllgl AiO HESIS AIH)gl) TO EXTlIACI OP
GlYlLE TISSlg
Tnl)ll G L(IHpslntillp (ypi(nl llld(~ SllOS (hat all a plngl of HIOK PlI((nt ot lltl pltl( Ilhl)(l acldpd to tllP Itll h iolJut1 InmiddottcJllP xhnet
of guayulp tiSI1( WllS 1l((PllIl Tlli nllintioll flOlll (olllplpU I((OYshy
PIY i within flll pxp(IiIlHuttllIIOI ~illli]llly fnbll Ii llows thn 1111 llYlIUgl of 1O(1~ ])(I(Pllt of gllllYllII 1(-i1l- add(d to II( (pllosol( (xshytrae of IUllY]l t i~HI Is 1l(oPIPI
THl~ (~ Hf (Off Ill of 1111)( J OJ I~il~ lItfI(( In ~(JI1IJk~ Ilf (111 [lI1Il fI2 lIII
0 tlUfllllit i~~I1
Instrument
---- ----~---- bull shy 1(1
Colemun ruono~ltrOUlllt()r 2t) II sJl~ctroJlhOL()lIIeter with 2tJ I iflllllI wnclength Fetting 21 II nntl 0-1111 WU HI hUJl(L _ L U
Ill 7Evolyn photo~lcclrie (olor JU [ imctcr with iO-llIl filler IV (I
H1 0 t I I
llImiddot lUn WII 1011 HIO Wn mil lUulon
10 JIg1111 IUI ml lUl anh Io aLn 111)_I ) III li lU It 2) deg wn2SU DD
Irl JIll II IIr II US II
1110(1 lULa lUI IlK) IJ WU
I( llI Htl tNI 1(111 2tlNI HI 0 221) lllil t2S 0 1~ 10 1~13
In (I 2117 I
10U 1l(J ~ 4 _H_j ___
9middotJIlJ5 10115 10 00 lUU5 flUU 4li (tl03 9(11)
leIlKl 1l~)5 lOOU l1KIr JOIS un 003 OIl Ii
34 lECHNlCAL BULLErIN 920 U S DEPT OF AGRICULlURE
COMPARISON OF PHOTOMETRIC A1D MODJIoIED SPENCE-CALDWfLL METHODS OF RUBBER ANALYSIS
Guayule samples were analyzed by the photQ111etIic method and by bull the modified Spenc(gt-Cnldwell mcthod The values in table 7 represhyselltativ(I of typical results indieate It -atisfactory dcglpe of conformshyjty between the two methods in thl range of tiSSlHH with llHHC than OJ) percent of rubbtImiddot On the bnsis of the amounts determimd the results in this runge for the plmiddotts(nt lIlcthod ayernge apploxinHltely j percent highcr
~LAIII~ 7-(oIllJl(i~on of lltlllrIic (IIri mOtllinl SJl(II(r-(ulri-wall IIIrtlwrl~ of rlrrlIIillillfl 11)1)(1 COIIrll of UI(III
1 Flowers frllm amiddotmonth-oltl nursery plants
YAIIIATJO- OF SIli(LE DETEnt1NATIONS Fnoll TnEIIllIEAN
Rllbbel (Uall8i8-Thc plcCision of thc pLcsent method when gunyule tissues Hr( nnnlyz((1 for rubber may be j udg(d flom I Ill datil presentcd in table H TIl(se dahl -how that thl pplCPlltag( uriation of single determinatiom from nwan yullles with low standllrd enolS ranges from less than 1 to 4 p(gtrlent
R(8in~ wWlsi-r-s lndi(a((1 011 page ~j he INntlts s((uled hy the present phoolllttric nsins llHt hod are not tliltly (olllpalable with those of the grtLVimetri( ncetol1l-cxtlt1(tioll II1etho(l Thjs made it necesSllry to selc(t another lalibllltion staudud-tlll Ipsinous exullate from gullyule shrub-thut gies relatively COllstlllt photometric readshyings (table 5) The resin (olltents of guayule roots branchcs or leavcs usually ran(~e from about) to 1-1middot pelcellt The ple(ision of the present methotf WhCll gUHyule thslllS lIe analyzed for reins may be judged from the datalHmiddotpscllted ill table 9 1h(se data show that the p(lcelltage variatiun of sillgle lhmiddott(Lminntions iLO11 meun ynlnes with low standard NTOrs rangcs from about 05 to 4 percent
bull
bull
bull
bull
bull
RAPID PHOTOMETHIC DElEruIINAlION OJ RUBBEH AND HESINS 35
IAIILE 8-luriation inclieute rubller (mallSM of [1wIIle tissue bll thc 1111O0Illclc metwII
Vnrlntlon~Ilbher I (rom mean
ierCtnl Percelll ~OU -22 ~ 25 +27 ~ 20 +18 ~UO -22---------1_______ 51110 0G6 bullbullbullbullbullbull _bullbull
10 ro ----=ii41075 -01 1000 +11 1010 +13
rlln HI itil 1l9~ 1_ ___ =-~~~
115511 ~ US -111 III II 1575 -13 115 b tiS -I a 111 h WlU +22IIM-(middot bull 11K -1Ja Illi c 1000 +03 1J5H1 W +l)7 ll1imiddot tl 1575 -13
Mcnn 15951 131
1102-11 21fJ() +21l102-h _ ~~)SO -17 1102-c bullbull 21CO +21n02middotd ~OIiO -26
2 r~plusmn Il~ 21151 261 I -~-------bull---__ _~~_~______l-___--_
1 lhe$ 1111($ I1n (or SlIlIIllltS Stpnnltplr PHrilClld IIrtlrdlng 10 1hr prollIlIlr( OIiIIiIl(o(I on Imgt$ 4 to IC ~tcond nUlI1 hlr r(J)[ltnts stl1ndnnl llrrot of tilt 1I1(1111
1_1l1~ n-J(lri(iot in relli(Upound rpoundsins (lllalIsfs of VIOJII( lixsue b1 the lhomillric lII(lloli
-- ---~--- - __-------- shybull I I I I Varlgttton
_________~___ ~~lu_n_Jl_Q_~~~_____ ______I__~_o~S_J frOID lDean
Percent Percentgt458-1 ~65 +41IWtl-li 130 -a2Hli8c aliO +26S41i8-d bull 130 -32
1(-011 34I10Olifgt __ bullbull __ ~--====
li-9~2n 881) -06 li-9~2-b Si5 o ~HH2middot(middot S i5 -6$-H2middotd 000 +1
8851 054
O i5 +6 9 i5 +6 950 -20 U75 +6
H-liG3o-n bull -1 n-li6~b bull __ _ -IH-IWH +4H-l61511 bull -1
1tmiddottlU
62~-lI __ 62~-b ij24-( bull OH-Ji
(-Ull
I rll(St oluls nre tor separately ~xlrflCled SllllllllCS IlctOrdlug lO procedure outllned ou pages 4 to 10 i Secoud number r~prtgeulS stulldMd error of lIe menn
36 TECHNICAL BULLETIN 920 t ~ DEPT OF A(]RICCLTCRE
ReUUER A~ALYSrS I~ CRCOE-RcuUER PROOCCTS
Sew rapid photometric m(lthod~fol the ddellllinttion of rubber and reii Hi ill uaYllp ti--ut htp lllell pIPHnl pd oil pag( ~l to In A brief H1111111tlY of It similar rnpid llHthod fm 1I1hb~rllnltlysis of u1lulcanizNl tlIldp lubbll pl(Hlmtlt whielt i~ bn-(tldo on the prill o
ciples dehtilcd tlllLe follows Duplltate nt-gm sllmph of the finely cliyiliNl IlInttlitiup wlirllll out [~ei-()l (all hl lIf((tinmiddotjv INd to lt1iyidl till alllpl) TIll kltolll-olubll portion of till )111(11( tlrc di-olved a- indh-Htpd fot thmiddot lllnkill~ of -tlllHlunlluhhll olutiou Oil Pt 1II hut tIl IUlIp Hn lIn l-fplImiddotd 10 lHI-ml rolllllltti( fln-k antil1ltld(lup to Olllll1l The bnlulUp or till JllO(ldllll i- thatutlilllll on paWs -1- 1 IHI Ii 111( 1(111 1- nIP IXPIP--pd nil til IHi or Iw oligiJla w(lullt of I Ill (I11l1p-I1l11Ilt1 1)(0(11(1
Hupitl PlllimiPJojgtiWllllllllh llIltllOd~ fOJ Ihl llPtlmiddotminntion of ImiddotUlJbll tlnd 1(-illo- ill -111111 Illllph of gutlYllll tiUl IIll dl-eli)ed 111() IlltlY d~o Ill nltlI1lld fOl III Iwl Illhlwl- and l~iJlmiddotb(lLiJlg plant TIllt l[Olllhup hns nlo b(l1l ntuptpl fot IIH lltlIll1illtltioll of lllhbpl ill 11lHhrublwl Pl(Jdlld~ HIIl 1111 hI ndaptld JoJ IIll ann lysis of ynt1J(gt( ic lllbbl[- The llllthmb HIP 1gtn(11 fill tIll fol1owill plimiph- III Grinding
tIll PIOPlly driPl t i~lIl 01 Ul tillg tIll pnHhHt to tll l((lllilllllh~lel of filWlH-- til plllllit qIHlIllilnth( lXIIHtioll 01 IIlbhlI 01 1(--IJl- () llsing oXWllutld olnuh (kttoJls IIt(talp and() fllltil for LIbbel and IH(ltIlIlyptIJllIllIoolYlnJld-o flJllh 101 niJlsl with t(lathelr high IlPililig points 111 to n C) l]olle or in mixt tIll thllt Pll mit tlll rnphllxututioll of luhll(l OJ [middot(ill ill ~() to (l mi1lutp It r(latiwly high 1lllIllllltlltP Ill to 1~11 ) l) lllllipitntillu till luhblI OL Imiddot(ill frolll aliquot () f till oltn ion I IlIlllI-i () f Hlltabhmiddot pl(~(i]litallt (willifhmiddotd lthmwl fOl IIlhlHI Hild llitlifild lllr fOJ JP-illl t~) IIlHkillphotollllliilPIIIIiIlof PlllPlltal of liht tLaIlS mittUl(P lIftlI IlIlbll (II Il in PIlipitalioll 11 II WI( Iplllh thnt (limiJlall till PIIOl dill 10 xtralllOlh (0101 (till dptl1minntinll Iph jill 011 tIll dtwlopllIlJIl of H HIli rOI1ll tlllbidity 111 hpl than I (olot rI
jJlIlpOP-ofallnlyi-I ( p(lllil1thb IIllijOI1ll turbidity or 1llt[lIinmiddotd d(ltl of jgtIp(ii(JlI l)~ lIltlkillU tIl plllltollllmiddottri( ntdillU al tandinu tiJlH~ (dlllilll wlli(h IhlllH(lill-- IP 1llutinmiddotly tnhll) t1ll1t an hlsl~1 oil the (oJlItlIlllItion of IIlhlHI Ill I(ill (lIPIipitat((L
TIll -I(p ill till jll()(Plhul HIP 1-- follOylt (1) 1l~UIIL uJ1lplls of thwl UJfJlllHl (II tliddl(l HUt dlipd 11Illtplial an lXIllltel with11 Ill of till nlnll ill t (oU tlllltIPlll[gtPImiddotatlup oil Iath at 11 Cbull fol 11 minutl I) iIP1lIin(middot(lohd til( (XUtllhllll Jltldl lip to It middotml ynlmlll til( (nlifild by (Illlifllgiuu HlId thlPl IlI nliql1ot of tIl (IalioPlllxUlltl nll Uillltlmiddotll(t to l-llll OIlIIlIllril fiuk- (1) For a trial Ilnditlg 0111 III tlll j liJmiddot~t IllHII IIjI to Ohlllll with lilt Pll shy(ilitnnl a 1(11 it 111 (Dod fill llli lIut ( ptotoJIIltlil IPtlllillg-- of pllllntnl or liuht tlUtllIlillal(I oil n (lpel OphotnJlllllI at rase hng-tlt (If 11 llJ Ill Ol It lollllil1lPtImiddott lloyidld with tIll P10]11 I 1110110shy
Ihlolllltt hmiddot Ii1llI Olllhi lIatioll for -1IpItillg UJlproXilll1l tply Wtl P ]Plwth )0 mp are HHlltk TIll Illldillg lliJtaillld fol tIlt 4-milutl tliall(~ll-
bull
bull
bull
RAPID PHOTO~IETRIC DETERIINATIOX OF R(BBER AXD RESINS 37
ing are referred to a table of equhmiddottllut~ previously p1(pa1elt1 on the
bull basis of 4-minute reac1inJ~ for tilE nmge of lot1telltlatiol1- of rubber or resins to bE elHOlll1t(led tmd gidn thtmiddot -tnnlillfr tillIP fill rUbbEt or resins aiter prE(ipitlltiol1 lwfolE photoIllNliI j(tltlill1 un IUade The r(middotnmining dllplllatt aliquot lll then HHllil up te ol1l1Jle and lpoundadillg ale marle ut the -tandillfr tiUlE iudklltll ill rhl tall1lmiddot for the final r(adillg~ -1) 111( milli1lnm or p(tCPlltllt- of lllhbpL (II 1(-in pr(s(nt are rpadholU a prlpan(l table of lquiltlput for tlll photoshymetric readings h1~l(l ill pnell e1-E on pxpPlilmlItal lhln 1111(1 u-ing as stimtlltlds pure luhbll in 1l1bbtl milllYb aIHI guaYllh ll-ill- lxIHlatt~ in resins detNIl1111lttion I
LlTERATlRE CLTED
(1) lUnSbull 1fl36 THE mURMIXTIOS IIF IOTA RE I III OOl THER llT~II
F1 bullrol IlY U(T1l0fll UfSlfi ~rrnrl r flm lt1 KEYS TI Bill Chern 114 44J-l59 illns
t1 ~ICPHHlObullbull T 1J3bull~ lUTHOO roa THE PtRInCAnu Or a(lIUl IRrIlHU It of TIn
PLRIHEU Htllllflt [ i Bill lallllall 111 Rmiddot 711middotj iIlus
I ) RHBERG P B Ul5 A METHIlO Or ~u(ronrll-nl Hi tIII rUIl[1 f71 ii illlI
bull 14 Hoss W flbull and HARDESTY J O
llH IR1ltDII Of HfITilIZfmiddotR DllIJS ltt 1 Yl fll Off gI bern JIIIlI i ~middotmiddotlf IIl
101 SPEltCE D nnd CuoWELr ~I L 1933 DETER~n-ATIOo OF RtBBER Ii nrllllpoundRBfR Iusr 1uI II1 amI
Em~ifl cttIliIa~~ r Ell i 71middot7i l11 (HI WALTER E D
1U44 ISO~nlS OF PRTlltSrr 1trHpoundV bull l UI n W lHHt (Tnmiddot 1ETS FROM GiYI l~iIl lItr Clttrn SII J UI titJ middotn9--C1 ilIu
17 J YOEbullbullr H lO~( roLORIlETRT 771 IPmiddot nl -W Yurk f H Plrwptric hmica
naly-II rimttry lUll XphHHlnmiddot~ y 1 1
11
HI) ~ fPHELolzTRf 57 111bull Lin xw Yk t H lt PhmeHt CblUlmiddot ila AnaiY~l~-(H lithrry and XIhmiddotILpfIY Y wirh enomiddot rrJlllrjr hy H KtlJnJU11 I
t~1I --- and ~ARVER L 1f41 nlua-w ~in L liLhr IS IP ll~ XIW Yrk
bull For-sale by th~ ~a~fr1nt~nf1ent Dt~c~~ogtnts-~ s t1i rArnn~ut Pn~~~ tJffieshy
Washington 5 D C bull Pl lU ~nts
bull
bull
bull
RAPID PHOTOlIElRIC DETEH-UXATroX OF ntBHEIl AXD HEstxs 23
ThE dula Pl(S(l1t(lltl indi(ntp Ihut 101 Illp ulimls llHthyl liohutyl htOlIl (lxtrHts (lI(I r(dolls of Il1Hxi11111III nigtol]gttioll wiH1I all (is-lIb 11 cOllsic1(]((l n1( blhn(11 wn ( ItIl( Its lIO to () I1It~ nlid Ii to Iii mJL
WhllNIS tlw I(gions of 1middottnL(s( light 1lnlllittamp al(l lgtPlW(PIl wan Ipllgtltsnr) to Ii nllt jW) 1I1JL nlld alio Silllill1l 111l1b (n SI(lIlId 101 nc(ton ]altmiddot(fmiddotollp-(llloolp ~ pxt Ill of 11a 1111 t illl TIl( (1101 du( to lolo ill tlw litlltitl a 1Il1 lullll(I tH lPill- hanmiddot bpllI PI(_ ipitated ma he 1((I1((d to fltI ynbhing poillt II ph( illg OJ illshylmiddotJall(( WIWp balld nhm ()) IIIJ1bullbull[1I111 lxjlPIitllll1b Illln -h()1 that Ih( lIIot uilahl( WHYI lHlIJ fOI 1-1 ill 1l11J1l(I HIH11Pill- illllllrsi i-in till IlPighl)()lllll()(l of ~llIl1lt bull
bull UIlIilHlIy of n typhn] lXPllillllllt to )10 l1iP(tiP ((JIlllo( of (ItOIS dul to lOIOl in 1llblnI Hnd Iill xtnumiddott 11(11 IIIIolp t jUl i p1llelll((l ill tub]lL Till llhlllt- 1tpIO]II Hnd ((llll~()h whit-h UI(I ](]Hllilltl n 1I01lllIhb1 01(111 lxt 11111 IIll 1llll)1 nmtp[in I and )(middotills Tid IIlnkl it poiblp nftlI tlIp uplll1tillll or tlll o1PIl( (0 [niH lip 1Iidl1p~ of lI111 11111(( ill lit ll11l1)[1 (llnlIb nlld Ihll
Sl(ll n ol1lliOI with tllP olnl IJllt illiollt HIl Iltlllll llllI (Ill ltllthpl prpipitnnt j Ihll1 nddld OUI ha a lIilPt lP( of till lIiciPlw of WH( lllIgth 7) lUI- ill llilllillatiu (nnl till tll Ixtll1I101l ()lll~
Tuu tmiddot-Elilll IJl flrldillY 11-1111 lrlllI IjfJI til islII 1 1(1 ([rllt IIIIIJIlIr JiIlIt~ if 1Il( Ihll 111111 k til I III Ilrln I 1Intd tf 11111 JiSf fill I I II I tIII Ilf Iilltl 1f1JlIIillII1f I Till 1[ 1 IId 1 (I (middotIt 11111 (I1I1iI1 1lf1IWtlfJlIIllfflr p middottrllhIJ11 II J III 7IImiddotIa 111 111 lilt jJIp 111 wilTII
t~t tnVIli~ ~nn r kn t~ i tmiddot ~~l Jr 1middotmt ltlTt
HmiddotOtt ~I~ lin t I ~ 1 t~~l ~qrmiddotthtmiddotrtwb
Hult-middottltlru t T Hw ullut rHtt~ r II I ~ PH~lllt
A~tmiddottHHjmiddott~rjd rl ~gtllh 1 tn~th~ ~ ~ middotI lt~ b w bull hmiddotth~ 1i~lIhun 1 Ii tnl Illd1 -11lt1(11i lullI lUI tJl ll~ t1~11n( I Ihan1li flfttIJir Ult I Uuhtltt ahuul l(hmiddottHmiddot~t trv r fti HIt lftbyl tlonhUt)1 k_hIl( 2 m~ fmiddotf tuhlHmiddotr In mlth~ llmiddotlf- 1 t r
t r_~ t j
Arhlitlltd ~llIIDHl NcWitn1 ( Ar-(lt()nc~middotttrrtrt ritJJI~ -Iu nllJtl4-middotr
ACtmiddottflnp fmiddotxtrn( ~ T-P511ftf tn mtmiddotth~ 1 ~difmiddotut~ kdn 2 nltt ulruhhtr in Un-tIl lltbu )J~IYt
rUth(Hl~hltlft HhubU
Illlh(I(t tttUtUt hUbtl til J ~jlitl(J Hilllll trtIIImiddotjtl1ll
(UShl I ~tlO wHllolH rulh r (middot1111$0]( J~rru t t )lthyl 15bullbull1middot1101 klll1l
Ili( UHUicbcul ~((i1rUtl ~ulu1iin 1middot lIUIll Ilti lrllltlllt I Ruhhr llt1thuI r1 -1 Irld
ltlt1111Sh 2 nuz f)rruhl~rm nlith~l tu- h f nt nil~middothgt(H] tlrlftmiddot 9lUtirtl middot1 1
rlcltfl( H(l dnllltml it
(IISllhH~rI( Iultruhtr CII05 1v ltTlft I 2 UI~r ublwr In llldh I hlt~1 11) lgtjdvr(llsl~9rlltmiddot middotlmin ~ I~ gt AIHItilltl no IrttipHallr iI
~ Bbnk 10ol m(thyl i~tmiddotut~i kdHn H 1 m1 j~~ l1rH-t lt~tlfltmiddotn sf n it ll HltlMjftr~nol O2~mlJ ~U~1o-ulp ti~tW -xtra~middotl(lt1 ltt 411 ml bull ie f Ct- kft rt t~ tirattJ middott ill r u l1kn ttJt
in metltl isobutyl kNqnf nn~i mljp ur tmiddotmiddot ~oml ~urr tttl i t w ltJj1JH kt 4t 3 nlank 1 mL((l1t~rthmiddot(middot mI mttr~ ~but a kmiddot tmiddotc d 11 ~ gtli~b~ hifIAft- fl~ lL lnti 149
ml8(dlfilll BO bull 02 gm guayule U$Stl(middot xUlClt-l tf(h tft wI n nmiddotmiddotmiddotlgt 1 lznt on tmiddot ~Jt r~1 ~~u~~ H~ iI~ thT
24 l$CHNlQAL BULLETlN l20l S DJltJPT OF AGHl(CLlOHJltJ
In table a is pl(sentc(l such c1il((t edlt1tIHC showing that thc (0101 Ixtrnetccl from guaYIIle tisslIe wit h II(P(OIl( n nd (pl1oso[yc is cll(div(ly sCIe(nec1 out by the s(lp(tion or wnw length )0 miL Oil t1w SI)((IOshyphotonwtpl This tnb]p all-HI ihos thai thl Juhlwl altl(l((1 (nn IJl quall shytitntivcly 1(I(()(Ipltl in tIlt PI(ilIH( or Ih (o]OIplnwPIials and Illsins and tlmt Iuhb(l WtlS nppnlllltly 1I0t (xtltI(((1 110111 11l glll1I1l lisslIt b~ tlHSP SOhlllts Thls( ((suIts ginmiddot (OliIHillg (idJt(( that t Iw IISI of waYl llngth i)ll 1Il) OIl till SppdTophot OIllltPI ii t hl 1101(1 p(oshy(ellule in photolllliTie IlIlalysis of luhhlI OJ l(sin-
SELEGTIO- OF )IOiOCUHO)IAIIC ItIIm ((1111110
On th( basis of th( IPHIlb shoWIl in tabl(l 1 al hlllpls (1( IIln(lp to SPCtl lC the PIO]Wl 11101lO(lIOl1ln til Ii ltlJ ((lIllIJi nIl ions 10 llIiOlS (oIOlimet(Is 111(gt 7W-Ill~ filtpl flllnhwd 101 til( I1~lI1l photoshyplpct1i( (o]oriJl1ltll fol which Ill( (hlll(IlIiitit~ oj t hl Ilda he light ilUIlBlIIhiSioll (t) elll nn -hO11 ill fig1lle 10 iws satlsfa(lolY IPshysultl 111( iiO-mL HitlI olllhintioll 101 whkh ttp (middotIatinmiddot light tlnnsmission (ullmiddotis a 1-0 showlI ill figllll (I is -nthdnlto1 hut this is not stnlHlnld NtllipmPlli
Up to fhl PlPHllt lIS(middotflll pound11((1 (ulllbinntions jn lltl iOO-I11L Iunge hayc nol bllll SlClIlld 101 lhp Klpt 1-1I1l1I11PISOIl (olOlinwtll bu fnltlwl nttCl1lpti 1( )(illg IlIHd
TJIpound OF ST~lmW AFTEH HIIJ1EII Oil HHSIS rlll~CIIITTI(J
~ considl1ltiol1 of ttp lillll of Inlllling af((1 plpeipital ion of 111gt)(1
01 l(sinSTlOIll ollltionis impoltant J(jl~ thC1HI(Plltngp of light IInIlSshy
11 rshy10 f shy
09 f shy ~750 Mil- DOMINANTI
~ 08 cshy I WAVE LENGTH z
I III III i O7 - I III
~06 - 05 shyw
a
Igti= 04 - 720 Mp DOMINANT ct WAVE LENGTH- ~ 03shy
02 f shy
01 t shy 1)O~~~gt~- J 600 700 800 900
WAVE LENGTH (Mp
bull
bull
bullFIGlRt IO- COJllPIUlItiw ~IW(middottltll tlnIlRlllii-lion (II (IllP( 101 1i11(1 olllhinulloll
with dominllnl Il(lllllgths at 720 and 7iO lUi
bull
bull
bull
HAPlD PHQTQlfE1IUC JjETER~lINATION OF Rnmrm AND HEtiINi 25
mitted (spertrophotoll1eleL lCuding-) Ol light (1 (tClcrl (phOlOshyJluol01l1et(L lcndillg~) i~ StlhjNl to (hangl
]fjt~l1le 11 and l~ show that ill til( (asc ot tJaugtIllitteltllight llJHC th~ (x[llliHlllIlnl (oIHlitiOllS tllpl j lilst n dtlln-e ill Pll~(lltngl or UllllslllittnlH( follrnY(l by It ptJiml of lClntin stability with only sliuht (1111 tHn- a f(Pl a lIt1ll1btJ of minutes The light t UIllllitblllll t l(1 ill(Iln~(s This lIIay IJP llllllJltlli7P(ll1 ffl II ow 1Ilt )( f(( darI oliIII tIIlIlNlIlitt(IIIlfJIIlh (iditilIiid Ilil1 pllIipintnl )uoshyIn Of ( 8inx in (~f1( I~iUII i~ Ild stahl I 11 itlll If 1inl nh prlshyilli(ioll of 11l1d(1 II IJIX f) jllIli II (fJJltfiIIlilty slllMI IIriot 1) IIIPldUnl1i tll(I1I rllltltilJl oj tJi~ Jlt jiot IUN ilUf Jxl1 will tIt( tOWI IItlllilil I 1llIlllblJIol I ill I~11l11111 d ill till ifjuids JjOI scnttplltl light 011 till phololltHJIOIl1lttl till dilPCt ion 01 elangl b tlw IPrfIi (If that illrli(atPll rOl tlulll1Jittp(lliuht It Itlll b( llluliJr I-(Pll that if l(middotndlnJ- IIIP mad n itl I t lIP ~()ll1d()lb lpalll this pllioJ of nmiddotlatirp tuigtility tllP llLot tIOllt thi Olll(P (nil bl IPdUCld to tIl lltini III 11 Ill TIll l~adiltg (illH~ bbll Oil tlHl datn rUl lublwls and llsinlt Illl ginll ill tnhh
50 r----------------------------------------------- f shyZ
~ 40 ~----~W~A~V~E~LE~N~G~T~H~7~5~0~M~P~~~~ ~ --------------------=-=-= ~ 30 f- WAVE LENGTH 540 M~ _z _____ ___ -=- __ _ ~ ------shyt ~_=---=-=--I GUAYULEIII 20 -Z HEVEA ltt II KOK-SAGHYZ f shy
4 6 8 10 12 14 (6 18 20 22 24 26 28 30 STANDING TIME (MINUTES)
FIlirtn 11 Emmiddot of wav hll~rh Il li~ltr tlall~lIIit1alHl aftI IUIlItHt -Imlli lug 111m for guaynh llmiddotn 011111 middotiolIlJh~z 1111111 llijlitul1 flolll 1lHlh~ll1Jllryl k11II11l ~(lilltlll h~ lwitlitll 111Inu1 111l~1It1 2)1111 o1U11111 (Helillins on (illllun tlunhll IlIIJlllw]ntllW111 lutl(I[lholtllllltlt with ijUjt Wlnl IHI Ilf1 I
11 EFFEGT OF Hbli 1 -()JXT10~
Tilt lnblwl ~()h(llh pxtnl( till IPillgt ubo It 1m nllu1- bellt -~atea thut ~lll 11-111- tUP olnbhmiddot ill middottIIlIlOl ~1It tlWIIJI( my U)t PIl (tlIHatcl WIth tl1l lullh(t I tahle lJ 1hln 1- -1111 tIll (llllstlOll of nny p()~iblt tITptt of XtIIl11 diflp]lws ill ((JlllPllttUliollS of 1l-in lil lolutioll alollJ with till 1lIltbpl TIU data ill wbh +ho on tIl( hn~is of (olorilllPill ladillU thaI tll( IIUOIl1t of lnbbll Plllipirntld 110111 Ilwthyl olnlld kptOlll olntioll IJ 1li-jHlllnt 1l)04 in 1-llltlIllt ethallol)- not amlll hy thl llllNlI(l of llvin aU1ouut of llins inolution bull
-----
26 rECHNICAL BULLEfiN 920 U S DEPl OF AGRICULlUHE
100
90
80(I) C)
z Ci 70 UI a 0 60 a ~ UI ~ 500 ~ 0 I Il 40
30
A 20
0
100
90
(I) 80 C)
z Ci 70 UI a 0
60a ~ UI E 0 50 ~ 0 I Il
4-0
30
B 20
0
--
--shy ---shy---
2 4 6 6 10 12 14 16
---shy= ~ ~ shy
-
2
025 05
10
15
20
25 -30
35 40
SO
-60
=70 80
16 20 2224 26 26 30
OS
- 10
IS
20
2S
30
35 40
-50
-60 -70 -80
bull MGPE 25-ML
VOLUME
bull
MGPER 25-ML VOLUME
Florm 12-EtTld (If till1l or Slllldill~ 011 light transmittallce (01 (A) gUllyulc lnUIl(I plccipitllitd frOIll llltt h~l isobutyl Ielollt solution Ily neidilic(l ethanul bull null (B) gUllyule ll~illii pre(ipitated flom aeltoll~lllcetOlll-Cl])osolY( 3-7 solushy11011 by H(illilip(i l1U (HPlldillg~ nt -lIlillult Ifllpluls 011 Evelyn photoelectric colorimellr with jU-lllp tlllll alit U-1I11 npN(lle spp also table 2)
bull
bull
RAPID PI-IOlOMEllUC DElEnMINAlION OF RUBBER AND RESINS 27
TADIbullbull ] 4-ReZation of amiddotmount of middottbber pleeipitate(Z Oln metltlIL isobutyl ketone 80lutions by OS-pereent H 2SO in 95-pere(lIIt ethanol to umollnt of resin8 udde(l U8 indivute(Z by colorimetrio readinU8
(Rubber ami resins cnlculntcd on bnsis of amounts in 5middotml ullquuts of extract from 02 gm of tissue in a 2fllll olumo( bull
Hubucl r~cocrell whcll rcsins nddcd as IndIcated Htbbor al1dcd (pllcollt) ---shy
__________bull_________ ~_12rpcrc~15011crccllt 7511crccnt IOOpcrcent
PerCtllt ercellt Percellt Percellt Percent o o o o o) 50 250 263 252 25000 500 500 500 500 700 750 750 751 749
1200 1250 1250 1250 1250
EXTRACTION TEMPEHATURE AND TIME
Typical experiments to detllmine the time required to secure maxishymum extmction of rubber und ltsills at 115deg U Ilre sUlIlmarized in figule 13 the solvents used-methyl isobutyl ketone for rubber anrl Ilcetonylacetone-cellosolve 3-7 for resins extraction-are very eflicicnt since under the conditions indicttted maximum values were secured after 30 minutes of ext1llction The most eflicient liquid for the bath (lig 1) used in extrtlcting rubber or resins is ~ high-grade cylinder oil (S A E ~O) The sand bath and such liquids as glycerol have proved unsatisfactory
RUBBER AND RESINS STANDARDS
According to the National BULeau of Standards 1-_ lhclc Is no gellcrnlly recoglllz(d standard lIIutcrlul [ior II rubber standard] The rubber hydroCllrbon ill llifferent samples of conmlcrciul smoked sheet or pale crepe from heclI pluntlltions nries from l~ 10 04 llercent of the totul nutletmiddot the most 11Ioruble conditions Of preparation
McPherson () has described a procedure for the pLeparation of pure heve~ (Hevea brasiliensis (H B K) MueH Arg) rubber from crude rubber or latex In the absence howevcr of ~ generally recogshyn12ed stalldard for rubber hydlQcllrbon [caoutchouc (CnHUs) xJ the standard adopted was that of the relnthely pure product secured from gunyule tissue txtractiotl nccording to the Spence-CaldweU method (5) or the motlified PIOCCdUlU of Hohnes lind Haasis (p 2) The details for constructing the calibration CULes are given on page 10 Standard rubber samples apparenl-]y can be stored for a long timc under the conditions des(libed on page 10 The duplicate colorimetric lendings for glULyule rubber newly extracted by the modified SpenceshyCaldwell method were ()J2 ench as compared with US) each for the sample extracted by the same method but stored 1 years In each case colorimeter rcadinllS were made on mixtures containing 2 mg of rubber in It 25-1111 Yolume
The selection of tt suitable standurd for guayule resins presents some dilliculties Tll(~ acetone extract of gUllyult estimated on (l gravishymetric busis~ for instance proved to be variable depending on the type of tissue sampled or season of sumpling because such fractions as
COllllllunlcntion dul(lt1 Octohtr 22 11H3
28 QECHNICAL BULLEQIN 920 U S DEPT OF AGRICTTIIlURE
16~==========================115 shy
14 bulli= 13 z ~ 12
ffi II Q
10 c w 9a w
8gto () 7w a
6a w
5en III ) 4 a
3
2
A 00 5 10 20 30 60 90
14~------------------------------------------- bull13
i= 12 z w II ()
a 10 w Q
9 c w 8 a w 7gt o () 6 w a 5 If)
z 4 If)
w 3 a
2
o+B~~__~__~____________~__________~ 5 10 20 30 60 90
HEATING TIME (111 NUTES)
lllGUltE 13-lDffect of time o( lICntillg O2-gm samples of gunynle tissue with solYlIt nt llfio C on lo(OVl)ry of lllhlJer alld 1Isim Lt HlIhblL extracted with methyl isohntyllwtone B resins Cxtll1cted with aCftonyla(etonc-cellosolve 3-7 bull
chlorophyll are weighed along with the resins in the acetone extruct but are not estimated by the present photometric method (fig 0) 1he use of a diffeJent stanclttrd waS therefore indicated
bull
bull
bull
RAPID PHOTOMETRIC DETERMINATION OF HUBBIm AND HESINS 29
The resins standard selected is based on n relatively pure source of resins the rcsinous exudnte 011 the stems of guuyule plants IJldimishynary expeliments with the resi nouS cxuclate from diffcrellt gllayu Ie strains of various ages indicatc nHlt there is little YaLiation in this subshystance on the basis of Colorimct(r readings 011 2-mg aliqllots of 01shypercent solution in It 2i-ml volume (tabl( li) Expelilll(lnts have shown that the air-dried (xuclate contains 3RtOH p(Ic(nt of -volatile matter This material is l(latiyt~ly stablp ill (OlllpoBition and is npshypurpntly on ly slight ly hygroBcopic as shoWIl ill Ia bl(1 1 Tlrp Ipsinolls exudate may be jJleplpd in two wayi-i fl liSP as a stallClHld-(l) the clpan exudate is clripd iol Ghouls at ()1deg C at W indlPs of a(lIum Hnd aftclbCinOglOund ill a molfalis 1)I(spI((I intn airtight COllilinel OL
(2) tllP Cx7lclate is clissolllt1 ill a(lhllll and filtplpd PlactieaJlyall of the acetm1l is thpn lYapolntwl olt OPI a stlam or atCt hath and Ow residue is dripd ground an(( PI(sPIld as ill tllp fin lllethocl Tlwse two prepalHtlolls a1( (ompalpd in ta hlp ) 111( (((tails fOl ~t()lil1g the resins standald and (onstlllcting the calibration CUITPS alc given Oil page ]2
lAIIIg fi-CUIIIllrsoi (lJ lIr-dr(1I IIIIi 1((11 II II-()I-tr((l l(sil~ 11111111(8 of I II 1111Ie
[Colorimetric rrndill~s 011 1~I11 phulll(Iclrie eolorillJct[lr with i~()middotmll (100- to iiOIIIIl) fillcr [lnd 5-1111 lIperture preeipitantl part ofO5middotPIrctllt 10 to 5 paris of IIOj
nupliclllc(oloritwt([
nIl(lin~s (hIlSlcAg~ ofSlmillXo JrNliltlCllt of fPsiJI$ L1Xtlrlntp on 2 IIIg ofplanls fllsins (XIHIIlt~Jwr 25-1111 vol
tII1(1) 1
leflTs Various _ bull ____ bullbullbullbull 3-9 Colll)Josiltrlairmiddotltlricfl bullbullbull nf)2 002
])0____ bullbullbull _bull __ _ bullbull ~-l Composilld (ri d at n5 C in aUmiddotimh lWUUllJ for l (jOuj(ja hours])0______ bullbullbull __ bull ___ bull 3-0 COJIlpositld disso]NI in neptolll f1l1erNl fl(lf()ll( GGO i(jO (Ivaporntld olT OV(1r Stpl1l11 halh TesidlH drl(ld I1t fi5deg ( ill anmiddotinch VIl(Unlll for 0 houlS bull
middot106 __ bullbull _ Jir~c1rild_~_~_ _~_ ~_~ _ ~ ____ _ __ _ OUu GOifina_~ ~ _ ~~_~ ___ _ _fln~ ~~ ~ ___ ~ __ 6(imiddotI tiliA H)[_ ltlu bullbull i18 tisSflOabullbullbullbull__ bullbullbullbullbullbullbullbull lt10bullbullbull _ tillO llitO406__ bullbull __ bullbull __ bull __ __ lt10_ Utl2 fon591_ fo__ bull liGa oOa 406bullbull _ __ lt10bullbullbull_ li5S OM
j Ph( vnluls in Uw Inst COIUIIlIl indieatp thnt gunyulp fesinous (IIHlnt( wlwtlwr dfircl hi Yn(tlLJ1l1 wilh L~ perc(nt loss of volntllt wutl pr or tWl c1rild giVPd npproxil1lnh1ly t Iw snllw colorinwtCr rNHiing- 011 till busis of aliquot~ cOlllniuiug 2 IJI~ of flsillS lXIHlntp l)tIf 25-mI volultl( Ihil- illdicate~ thl11 Uw UITW IJ1flS~ of olnshytile mntl(f prt~(iJlitnt(d gins npproxilllntlly Uw $1II1l (oiOfirnl1tlf ftudiTlJs ns tho ftsidtw A pnlill1jllaf~middot (XIlltrinllnt indicutls thlli th VUllltill muller l(lIlSists of thl Ilrplne oil fmcl ion I5-(1Il gtnplls or rlsitlOtlS (lxudntll gnvll by stPll1U distillation nn Uefllgl of 011111 of jl(lfPlIW oil with npproximHte tilllsity (If OHIi lind lhus rrprlsll1ll( IlPIJroximllt(I~ 01 Jerccllt Of t he original weight 1hls lllrClnlage complrcs wllh 38 llltrC(ntlost by drvinI( in IICllnllJ
aSplusmnUH perceilt or orlginlll weightlosl
The wailnble illfolJllntioll on tlH (ow-JitlPllts of the gunYllle r(~shyillOllS exudate alld tl1( HeetOlIP ext act of gaylp ti~slw is sllIllmarized in this paragraph lYalttI (u) alld also Hangcn-Slllit lind his coworkshyers 16 reported that 20 percent of the resinolls exudate from gUltyulc stems is parthenyl cinnamaie (CHuOH=CHC020 11JI2r) Steam disshy
15 (OIlIJIIIIUicatioll flom A T Haai(II~l11it llId (0011(11 Calif0111 ill Tnfiitnte of Tccllllology Past(IlIJI Jhps( wOlken al Htud~ing the COTlHlitlllllts of the acetone extract and other conlltituellis of guuyule
30 TECHNICAL BULLETIN 920 U S DEPT OF AGRICULTURE
tillation of similar resinous exudate in the writers laborntory has yielded approximately 4 percent of the whole as the telmiddotpene oir fracshytion Haagen-Smit and his eoorktrs nportec1 thttt about 25 percent of the acetone extract from guayule branches is parthenyl cinnamate and 6 percent of the bark (ltortpamp-phlotm) extraet is parthenyl cinshynamate These workers fm-thcI reported that 25 lwletnt of the nc(shytone extract frolll bLllllches is a compound with the tlI1pilicaL formula CBoH400a 1 percent is a compound llwltillg at 2P to 2T5deg C and 1 percent of the extract from the ]eav(s is tl (olllpoulld nwlting at 100
to 1710 1Valtei (6) reported that 3 to -l perc(nt of the tI(eton( txtract
of leaves and flowering StPIllS of guayulc eonsists of waxlike substances soluble in olgallic soln~nts but insoluble in at(l and (on(ent1llted H 2S04 The flactions mentioned on the basis of (onHLTutle esti shymates of amoullts actually isolated tlecoullted for about H ptIcent of the totalncetollt~ so]ubles extracttd from tll( guuYllle 11 rub The other constituents ltlilaill to be i(](ntifi(d
RUBBER AND RESINS CALIBHATION CVHES
Typical culibndioll Clllves iol Iuhbpl and I(sins bas(d 011 (ldtLminttshytions made nccoLdillg to the plocCdmC outlin(d 011 pages middotb to 1G arc shown in figulPS 5 and 1+ The spCdlopliotoll1lttL en (OIOIjlllctCI readings are plottCd on s(lIlilogalitllllliC pappi ag-ail1st (Il 11IbblI (011shy
100 ~ 90
80 ~ 70 ~
z 1amp1 0 II 1amp1 IL
1amp1 0 Z
60
50
40 ~ltI 30 ~ en z ~ ltI II ~ 20 C) ~ oJ
10 o 2 3 4 5 6 7 8 9 10
RU8BER IN 25-ML VOLUME (MG)
bull
bull
bull FI(lURE 14--Ctlihration curve fotmiddot gllftYlIlc lubb01 (Hct(lings Oil COIPIIHlII tlOl1hl(
monochromator SlCClrophotolllet(r with 7fiO-11IL Illtel alld Hllp Wll ( IHlll()
bull
bull
bull
RAPID PHOTOMETRIC DETE~MINATION OF RUBBER AND RESINS 3]
centrations From a casual inspection of these CUlTes it would appeltr that Beers law does not hold Actual tests indicitted that Beers law was applicable only within a narrow range in the upper portion of the curves The analyticlil results on the basis of photornetric readings nre therefore calculated by direct reference to calibration curves or from reference tables of equivalent values bllscd on the cnlibllltion curves
Calibration curves for kok-saghyz alld heyea lI11tulltl rubbers and Buna S (GR-S Chem Gum IV Goodyear) and butyl (GR-I Standshyard Oil Co Protoc) sYJlthetic rubbers are hOWllil1 figure 15 The samples of kok-saghyz rubber were furnished by the Diyision of Rubshy
100
90 ~I) ()
z 0
1amp1 a
~ a
80
70
60
s 1amp1 ~ ~ 0 ~ KOj-SAGHYZ 0 l Il
50
HEVEA~ ~
40
100
90
~ 0 80z Q 70a Co)
a 60 ~ 0 0 x 50Il
40 ~----~~----~------~------~------~--~ o 2 3 4 5
RUBBER IN 25-ML VOLUME(MG)
FmUIlE 15-CaJiblation curves fOl kok-snghyz h(YCII Bunn S lind butyl rubb~ls (Readings on gy((yn photoelectric colorimeter with i20-lIIp filtpl and 6-ml aperture)
32 TECHNICAl BUIJLETIN [)20) 1 S DEP1 OF AGrnCUIlfURE
Iwt Plant JIl(I~t ignlioll of thi BlII(un and (1( l))(parcd according to 11( SPltI1((-Culd (]] (6) PIO(((lllll Hlpt pal( CLPPe was (xtmch(L with acetone blI()Ieit W 1I(gt(11l a ttnlldal(l
SEXSlllVllY Ol~ llETJIonS
By lip pIO((l(II11P olltlillP(l 011 ]Hlg( +n Iowa (lOOl IIIg (11 1111i(l0shygmm (gHlllllla) of 1hblI ill a 2)1111 yoltll1ll (all )(gt dltpltld Oil tltl Col(man (lohlP mOIlWhlOl1lHlOl l-I)((t 101 l1lOt 0111 ci( I ill1ilnlly 001 mg of Iublwr ill a 2J-1ll1 n]ulllP Illay bl Ilad Oil till EnI)1I photoshyllectlie (O]oLillllt(I Thll ya lllll- 011 tilt IHl-i- (J I (xl ad iOI1 fmlll 02 gill of til-lI tH(JI(lillg to tllP -lllndal(l jll()(pdull 1(PIPStlIt IlO()2J tlnd 002) P(IT(lIt of llIbl1ll IPI)(((inly bull1t1lollgh -lI1t low allils can be d((d(middot(1 il lIoullt1 Ill IPtllizpd thnt till PIIOl ill PlI(Plltng( or tll( al110unt dltlIllIilll(J i ltlatlpl high ill tili PIY lo Itlllgl 111 aetllllllladie(middot Ill( lopl lillliL 111)(1(1 lIw (ollllil ions of tlil ]lI()(lltlIIIl u ol1tlinpd ipt at l11 11I1 or 1111gt11(1 illt i-1ll1 Ollllll IlPIPltPlltillg 01 p(gtl(pnt of JllUiJtL un tlll 1Hli or (xlla ion rlOI11 II rlll of tisSIll
EIlIlOH COSIIlIHIIO
In Oldpl to H(IIp ill )1lHtPltt pl((iioll illlpIi1I- it i lH((SSHI to slnlldHIdiz(i rigidly 111( Pl()((dlll( 0 illdi(ntpd Oil pnglt- - to J( If lids i dOlH tlip lXIHlinwnlal PIIll is t(middotdllld 10 n ndninlllill
Illlt pl(iioll of (hI ]lIPPllt 1IHllwd Oil til basi of ]llllP llIllJt1 alld Ipsinssollltions call hI jlldgl(J 110111 figllll Hi lileh lio- til HPIlIgl d(intioll oft -illgIP lI1lnSIlIlIIIlnt in lHi((lltagl of Ill( alllOllllt 01 Illhshy1)() 01 lpsins d((PI1I1 iJlld TIl( (1101 PlI(Plltaglt H1( gi (1 101 OJ) to
RUBBER IN 25-ML VOLUMEMG) 004 01 02 03 04
i= I I IZCtOW
fbA ICtU CtCt WW a
01 02 03 04 05 06 07 08 09 100 = RUBBER (PERCENT)
RUBBER IN 25-ML VOLUME (MG) 10 20 30
~ I CtZ
bBOw Ctu CtCt Ww o I~
010 50 100 150 200 250 RUBBER (PERCENT)
RESINS IN 25-ML VOLUME(MG) 10__ __3-0_ 40 50 60 70 60 90 100--_-- 2_-0
Ct~ -r- 1 I OZ
WCt UCt b C wCtW
a o I I 150 250
RESINS (PERCENT) o 10 50 100 200
bllI 1tI W-Yllnl dtd1 ioll I I 11l1 11IlI11 1(111(11 1 III Plll- IlIIIlol1 01 IIim~
bull
bull
bull solution Il basis J o golH of tiSSII (JlILCl-nt (11(11) for (~I) (l)1 til O 1I1
of luhllpl lin 1 III I (I Ill of lUhlJPl nllll laquo I J to 111 nlg of IlSlllgt (Itllillgs on ]iYllyu pllolwh-llrk CO[IJlilll(-(PI with nOHIP Iiltlr lIntl U-lIll allcrture)
RAPID PHOTOlJElRIC DELEHlllNAllON Cn HUBBER AND H1~SINS 33
10 mg of rubber anel1 to 10 mg of resins in a gJ-m1 yolumC For
bull
bull
bull
comparative ptuposes the leslllts arc also calculated on the basis oJvershycentage rubber OL tltsills in 02 gllI of tissul As WOlllL be expcet(d the error increases sOIlHgthlf for 1(lali nmiddotly low COlHell t1llf iOlls oj rllbbeL or resins The curves in figure 1(j s1l0 that ill til(gt Illlge Ol to 10 pCrshyeent of lubber the elTOI rangts Jroll1 abollt Ll to II) ]IlC(lIt abo(~ this mlllc tIlt (ITOl d(((ts(s to (ollsidlItbly ltmiddotss (han 1 1lICPllt of tlH mllollnt ltl((Lmill(d Hil1lilally in tlH (lISl of l(sins analysis (fig 10) the ltLTor is (onsit1eIubly INS than 1 PlLllnt ill (he lallgp of 11 t~) ~() penPII t
In nil ([lSl of lllhblI alld (sins lx(Inltpd tIOIl1 (issups Ol addcltl to tisslle lxtlads (s(( tabhmiddots (i H) illyolillg ll01P o(lllntiolls the eLI01
is hig]wl thun that indilHtld in figllll ((j Im pUIl Ill )])p I tllllllsins solutlOII
COlllUCIIOXFOH IXSOLl-IlLl~ Ilgsqgt(Jg
111 th( Jllo(pdulP ollllillPd 011 paw I till illsolllhll isSII Ipidll( tflpl (xttlw(ioll is (Ptill tlw lIask l(lll till xtlct i l1wdp up to yoltlllH It is not rOllPllipnt (0 IPt()PI qWlIltitati(Ir III(lw[olH a 11(1 pllooll extlnlfs of guuyull I is-lll alll thl1l main t11l111 up (0 YOIUllllmiddot bpCaUHI sllch all additiollal stltp wottld]) tillll-C(JllS11ll1illg Th( Iogiea nll(gtIshynntin is to mnkp tltl lXtlUCt Llld Ipsidup lip to OllillH in till original flask andi llPSStllY 10 llwlno tl OIIpdioll wlHIl (allIlnting [hc llshy
Hults f(JI [hl oll111lC displupd hy till ins()lllbh llsidll( III it l)picat (IXpednHllt (ollsisting of Jhp lppJiea(iolls if was Iollnd llftt at ~iiO ( 02 gill 01 Iuhhll pillS IPill-fl(( lisslI(gt (lollpdll fot llwistUlC ou basis of dlyillp ut lOW 101 ) llOlll-j (lbp(ld only t~ llllUll voiul11P of OOk7D~- OO(lOO(i Ill of lllthyl bolnl(yl 1lIOll( (lplhlli(al-t(Tnltle sp gl () Ii I ll(Hli (j at ~)) -gtitllP tl1(gt 1It101111( () r t is-lIl xt Iadld j sl1lall til( PlIOI dul to Ill(gt insoll1blp Ip~idll is slllall III [0111 ill( wOtk it (all lJp diIpgal(ll(l
]hcon~lIY OF HllIllgl AiO HESIS AIH)gl) TO EXTlIACI OP
GlYlLE TISSlg
Tnl)ll G L(IHpslntillp (ypi(nl llld(~ SllOS (hat all a plngl of HIOK PlI((nt ot lltl pltl( Ilhl)(l acldpd to tllP Itll h iolJut1 InmiddottcJllP xhnet
of guayulp tiSI1( WllS 1l((PllIl Tlli nllintioll flOlll (olllplpU I((OYshy
PIY i within flll pxp(IiIlHuttllIIOI ~illli]llly fnbll Ii llows thn 1111 llYlIUgl of 1O(1~ ])(I(Pllt of gllllYllII 1(-i1l- add(d to II( (pllosol( (xshytrae of IUllY]l t i~HI Is 1l(oPIPI
THl~ (~ Hf (Off Ill of 1111)( J OJ I~il~ lItfI(( In ~(JI1IJk~ Ilf (111 [lI1Il fI2 lIII
0 tlUfllllit i~~I1
Instrument
---- ----~---- bull shy 1(1
Colemun ruono~ltrOUlllt()r 2t) II sJl~ctroJlhOL()lIIeter with 2tJ I iflllllI wnclength Fetting 21 II nntl 0-1111 WU HI hUJl(L _ L U
Ill 7Evolyn photo~lcclrie (olor JU [ imctcr with iO-llIl filler IV (I
H1 0 t I I
llImiddot lUn WII 1011 HIO Wn mil lUulon
10 JIg1111 IUI ml lUl anh Io aLn 111)_I ) III li lU It 2) deg wn2SU DD
Irl JIll II IIr II US II
1110(1 lULa lUI IlK) IJ WU
I( llI Htl tNI 1(111 2tlNI HI 0 221) lllil t2S 0 1~ 10 1~13
In (I 2117 I
10U 1l(J ~ 4 _H_j ___
9middotJIlJ5 10115 10 00 lUU5 flUU 4li (tl03 9(11)
leIlKl 1l~)5 lOOU l1KIr JOIS un 003 OIl Ii
34 lECHNlCAL BULLErIN 920 U S DEPT OF AGRICULlURE
COMPARISON OF PHOTOMETRIC A1D MODJIoIED SPENCE-CALDWfLL METHODS OF RUBBER ANALYSIS
Guayule samples were analyzed by the photQ111etIic method and by bull the modified Spenc(gt-Cnldwell mcthod The values in table 7 represhyselltativ(I of typical results indieate It -atisfactory dcglpe of conformshyjty between the two methods in thl range of tiSSlHH with llHHC than OJ) percent of rubbtImiddot On the bnsis of the amounts determimd the results in this runge for the plmiddotts(nt lIlcthod ayernge apploxinHltely j percent highcr
~LAIII~ 7-(oIllJl(i~on of lltlllrIic (IIri mOtllinl SJl(II(r-(ulri-wall IIIrtlwrl~ of rlrrlIIillillfl 11)1)(1 COIIrll of UI(III
1 Flowers frllm amiddotmonth-oltl nursery plants
YAIIIATJO- OF SIli(LE DETEnt1NATIONS Fnoll TnEIIllIEAN
Rllbbel (Uall8i8-Thc plcCision of thc pLcsent method when gunyule tissues Hr( nnnlyz((1 for rubber may be j udg(d flom I Ill datil presentcd in table H TIl(se dahl -how that thl pplCPlltag( uriation of single determinatiom from nwan yullles with low standllrd enolS ranges from less than 1 to 4 p(gtrlent
R(8in~ wWlsi-r-s lndi(a((1 011 page ~j he INntlts s((uled hy the present phoolllttric nsins llHt hod are not tliltly (olllpalable with those of the grtLVimetri( ncetol1l-cxtlt1(tioll II1etho(l Thjs made it necesSllry to selc(t another lalibllltion staudud-tlll Ipsinous exullate from gullyule shrub-thut gies relatively COllstlllt photometric readshyings (table 5) The resin (olltents of guayule roots branchcs or leavcs usually ran(~e from about) to 1-1middot pelcellt The ple(ision of the present methotf WhCll gUHyule thslllS lIe analyzed for reins may be judged from the datalHmiddotpscllted ill table 9 1h(se data show that the p(lcelltage variatiun of sillgle lhmiddott(Lminntions iLO11 meun ynlnes with low standard NTOrs rangcs from about 05 to 4 percent
bull
bull
bull
bull
bull
RAPID PHOTOMETHIC DElEruIINAlION OJ RUBBEH AND HESINS 35
IAIILE 8-luriation inclieute rubller (mallSM of [1wIIle tissue bll thc 1111O0Illclc metwII
Vnrlntlon~Ilbher I (rom mean
ierCtnl Percelll ~OU -22 ~ 25 +27 ~ 20 +18 ~UO -22---------1_______ 51110 0G6 bullbullbullbullbullbull _bullbull
10 ro ----=ii41075 -01 1000 +11 1010 +13
rlln HI itil 1l9~ 1_ ___ =-~~~
115511 ~ US -111 III II 1575 -13 115 b tiS -I a 111 h WlU +22IIM-(middot bull 11K -1Ja Illi c 1000 +03 1J5H1 W +l)7 ll1imiddot tl 1575 -13
Mcnn 15951 131
1102-11 21fJ() +21l102-h _ ~~)SO -17 1102-c bullbull 21CO +21n02middotd ~OIiO -26
2 r~plusmn Il~ 21151 261 I -~-------bull---__ _~~_~______l-___--_
1 lhe$ 1111($ I1n (or SlIlIIllltS Stpnnltplr PHrilClld IIrtlrdlng 10 1hr prollIlIlr( OIiIIiIl(o(I on Imgt$ 4 to IC ~tcond nUlI1 hlr r(J)[ltnts stl1ndnnl llrrot of tilt 1I1(1111
1_1l1~ n-J(lri(iot in relli(Upound rpoundsins (lllalIsfs of VIOJII( lixsue b1 the lhomillric lII(lloli
-- ---~--- - __-------- shybull I I I I Varlgttton
_________~___ ~~lu_n_Jl_Q_~~~_____ ______I__~_o~S_J frOID lDean
Percent Percentgt458-1 ~65 +41IWtl-li 130 -a2Hli8c aliO +26S41i8-d bull 130 -32
1(-011 34I10Olifgt __ bullbull __ ~--====
li-9~2n 881) -06 li-9~2-b Si5 o ~HH2middot(middot S i5 -6$-H2middotd 000 +1
8851 054
O i5 +6 9 i5 +6 950 -20 U75 +6
H-liG3o-n bull -1 n-li6~b bull __ _ -IH-IWH +4H-l61511 bull -1
1tmiddottlU
62~-lI __ 62~-b ij24-( bull OH-Ji
(-Ull
I rll(St oluls nre tor separately ~xlrflCled SllllllllCS IlctOrdlug lO procedure outllned ou pages 4 to 10 i Secoud number r~prtgeulS stulldMd error of lIe menn
36 TECHNICAL BULLETIN 920 t ~ DEPT OF A(]RICCLTCRE
ReUUER A~ALYSrS I~ CRCOE-RcuUER PROOCCTS
Sew rapid photometric m(lthod~fol the ddellllinttion of rubber and reii Hi ill uaYllp ti--ut htp lllell pIPHnl pd oil pag( ~l to In A brief H1111111tlY of It similar rnpid llHthod fm 1I1hb~rllnltlysis of u1lulcanizNl tlIldp lubbll pl(Hlmtlt whielt i~ bn-(tldo on the prill o
ciples dehtilcd tlllLe follows Duplltate nt-gm sllmph of the finely cliyiliNl IlInttlitiup wlirllll out [~ei-()l (all hl lIf((tinmiddotjv INd to lt1iyidl till alllpl) TIll kltolll-olubll portion of till )111(11( tlrc di-olved a- indh-Htpd fot thmiddot lllnkill~ of -tlllHlunlluhhll olutiou Oil Pt 1II hut tIl IUlIp Hn lIn l-fplImiddotd 10 lHI-ml rolllllltti( fln-k antil1ltld(lup to Olllll1l The bnlulUp or till JllO(ldllll i- thatutlilllll on paWs -1- 1 IHI Ii 111( 1(111 1- nIP IXPIP--pd nil til IHi or Iw oligiJla w(lullt of I Ill (I11l1p-I1l11Ilt1 1)(0(11(1
Hupitl PlllimiPJojgtiWllllllllh llIltllOd~ fOJ Ihl llPtlmiddotminntion of ImiddotUlJbll tlnd 1(-illo- ill -111111 Illllph of gutlYllll tiUl IIll dl-eli)ed 111() IlltlY d~o Ill nltlI1lld fOl III Iwl Illhlwl- and l~iJlmiddotb(lLiJlg plant TIllt l[Olllhup hns nlo b(l1l ntuptpl fot IIH lltlIll1illtltioll of lllhbpl ill 11lHhrublwl Pl(Jdlld~ HIIl 1111 hI ndaptld JoJ IIll ann lysis of ynt1J(gt( ic lllbbl[- The llllthmb HIP 1gtn(11 fill tIll fol1owill plimiph- III Grinding
tIll PIOPlly driPl t i~lIl 01 Ul tillg tIll pnHhHt to tll l((lllilllllh~lel of filWlH-- til plllllit qIHlIllilnth( lXIIHtioll 01 IIlbhlI 01 1(--IJl- () llsing oXWllutld olnuh (kttoJls IIt(talp and() fllltil for LIbbel and IH(ltIlIlyptIJllIllIoolYlnJld-o flJllh 101 niJlsl with t(lathelr high IlPililig points 111 to n C) l]olle or in mixt tIll thllt Pll mit tlll rnphllxututioll of luhll(l OJ [middot(ill ill ~() to (l mi1lutp It r(latiwly high 1lllIllllltlltP Ill to 1~11 ) l) lllllipitntillu till luhblI OL Imiddot(ill frolll aliquot () f till oltn ion I IlIlllI-i () f Hlltabhmiddot pl(~(i]litallt (willifhmiddotd lthmwl fOl IIlhlHI Hild llitlifild lllr fOJ JP-illl t~) IIlHkillphotollllliilPIIIIiIlof PlllPlltal of liht tLaIlS mittUl(P lIftlI IlIlbll (II Il in PIlipitalioll 11 II WI( Iplllh thnt (limiJlall till PIIOl dill 10 xtralllOlh (0101 (till dptl1minntinll Iph jill 011 tIll dtwlopllIlJIl of H HIli rOI1ll tlllbidity 111 hpl than I (olot rI
jJlIlpOP-ofallnlyi-I ( p(lllil1thb IIllijOI1ll turbidity or 1llt[lIinmiddotd d(ltl of jgtIp(ii(JlI l)~ lIltlkillU tIl plllltollllmiddottri( ntdillU al tandinu tiJlH~ (dlllilll wlli(h IhlllH(lill-- IP 1llutinmiddotly tnhll) t1ll1t an hlsl~1 oil the (oJlItlIlllItion of IIlhlHI Ill I(ill (lIPIipitat((L
TIll -I(p ill till jll()(Plhul HIP 1-- follOylt (1) 1l~UIIL uJ1lplls of thwl UJfJlllHl (II tliddl(l HUt dlipd 11Illtplial an lXIllltel with11 Ill of till nlnll ill t (oU tlllltIPlll[gtPImiddotatlup oil Iath at 11 Cbull fol 11 minutl I) iIP1lIin(middot(lohd til( (XUtllhllll Jltldl lip to It middotml ynlmlll til( (nlifild by (Illlifllgiuu HlId thlPl IlI nliql1ot of tIl (IalioPlllxUlltl nll Uillltlmiddotll(t to l-llll OIlIIlIllril fiuk- (1) For a trial Ilnditlg 0111 III tlll j liJmiddot~t IllHII IIjI to Ohlllll with lilt Pll shy(ilitnnl a 1(11 it 111 (Dod fill llli lIut ( ptotoJIIltlil IPtlllillg-- of pllllntnl or liuht tlUtllIlillal(I oil n (lpel OphotnJlllllI at rase hng-tlt (If 11 llJ Ill Ol It lollllil1lPtImiddott lloyidld with tIll P10]11 I 1110110shy
Ihlolllltt hmiddot Ii1llI Olllhi lIatioll for -1IpItillg UJlproXilll1l tply Wtl P ]Plwth )0 mp are HHlltk TIll Illldillg lliJtaillld fol tIlt 4-milutl tliall(~ll-
bull
bull
bull
RAPID PHOTO~IETRIC DETERIINATIOX OF R(BBER AXD RESINS 37
ing are referred to a table of equhmiddottllut~ previously p1(pa1elt1 on the
bull basis of 4-minute reac1inJ~ for tilE nmge of lot1telltlatiol1- of rubber or resins to bE elHOlll1t(led tmd gidn thtmiddot -tnnlillfr tillIP fill rUbbEt or resins aiter prE(ipitlltiol1 lwfolE photoIllNliI j(tltlill1 un IUade The r(middotnmining dllplllatt aliquot lll then HHllil up te ol1l1Jle and lpoundadillg ale marle ut the -tandillfr tiUlE iudklltll ill rhl tall1lmiddot for the final r(adillg~ -1) 111( milli1lnm or p(tCPlltllt- of lllhbpL (II 1(-in pr(s(nt are rpadholU a prlpan(l table of lquiltlput for tlll photoshymetric readings h1~l(l ill pnell e1-E on pxpPlilmlItal lhln 1111(1 u-ing as stimtlltlds pure luhbll in 1l1bbtl milllYb aIHI guaYllh ll-ill- lxIHlatt~ in resins detNIl1111lttion I
LlTERATlRE CLTED
(1) lUnSbull 1fl36 THE mURMIXTIOS IIF IOTA RE I III OOl THER llT~II
F1 bullrol IlY U(T1l0fll UfSlfi ~rrnrl r flm lt1 KEYS TI Bill Chern 114 44J-l59 illns
t1 ~ICPHHlObullbull T 1J3bull~ lUTHOO roa THE PtRInCAnu Or a(lIUl IRrIlHU It of TIn
PLRIHEU Htllllflt [ i Bill lallllall 111 Rmiddot 711middotj iIlus
I ) RHBERG P B Ul5 A METHIlO Or ~u(ronrll-nl Hi tIII rUIl[1 f71 ii illlI
bull 14 Hoss W flbull and HARDESTY J O
llH IR1ltDII Of HfITilIZfmiddotR DllIJS ltt 1 Yl fll Off gI bern JIIIlI i ~middotmiddotlf IIl
101 SPEltCE D nnd CuoWELr ~I L 1933 DETER~n-ATIOo OF RtBBER Ii nrllllpoundRBfR Iusr 1uI II1 amI
Em~ifl cttIliIa~~ r Ell i 71middot7i l11 (HI WALTER E D
1U44 ISO~nlS OF PRTlltSrr 1trHpoundV bull l UI n W lHHt (Tnmiddot 1ETS FROM GiYI l~iIl lItr Clttrn SII J UI titJ middotn9--C1 ilIu
17 J YOEbullbullr H lO~( roLORIlETRT 771 IPmiddot nl -W Yurk f H Plrwptric hmica
naly-II rimttry lUll XphHHlnmiddot~ y 1 1
11
HI) ~ fPHELolzTRf 57 111bull Lin xw Yk t H lt PhmeHt CblUlmiddot ila AnaiY~l~-(H lithrry and XIhmiddotILpfIY Y wirh enomiddot rrJlllrjr hy H KtlJnJU11 I
t~1I --- and ~ARVER L 1f41 nlua-w ~in L liLhr IS IP ll~ XIW Yrk
bull For-sale by th~ ~a~fr1nt~nf1ent Dt~c~~ogtnts-~ s t1i rArnn~ut Pn~~~ tJffieshy
Washington 5 D C bull Pl lU ~nts
24 l$CHNlQAL BULLETlN l20l S DJltJPT OF AGHl(CLlOHJltJ
In table a is pl(sentc(l such c1il((t edlt1tIHC showing that thc (0101 Ixtrnetccl from guaYIIle tisslIe wit h II(P(OIl( n nd (pl1oso[yc is cll(div(ly sCIe(nec1 out by the s(lp(tion or wnw length )0 miL Oil t1w SI)((IOshyphotonwtpl This tnb]p all-HI ihos thai thl Juhlwl altl(l((1 (nn IJl quall shytitntivcly 1(I(()(Ipltl in tIlt PI(ilIH( or Ih (o]OIplnwPIials and Illsins and tlmt Iuhb(l WtlS nppnlllltly 1I0t (xtltI(((1 110111 11l glll1I1l lisslIt b~ tlHSP SOhlllts Thls( ((suIts ginmiddot (OliIHillg (idJt(( that t Iw IISI of waYl llngth i)ll 1Il) OIl till SppdTophot OIllltPI ii t hl 1101(1 p(oshy(ellule in photolllliTie IlIlalysis of luhhlI OJ l(sin-
SELEGTIO- OF )IOiOCUHO)IAIIC ItIIm ((1111110
On th( basis of th( IPHIlb shoWIl in tabl(l 1 al hlllpls (1( IIln(lp to SPCtl lC the PIO]Wl 11101lO(lIOl1ln til Ii ltlJ ((lIllIJi nIl ions 10 llIiOlS (oIOlimet(Is 111(gt 7W-Ill~ filtpl flllnhwd 101 til( I1~lI1l photoshyplpct1i( (o]oriJl1ltll fol which Ill( (hlll(IlIiitit~ oj t hl Ilda he light ilUIlBlIIhiSioll (t) elll nn -hO11 ill fig1lle 10 iws satlsfa(lolY IPshysultl 111( iiO-mL HitlI olllhintioll 101 whkh ttp (middotIatinmiddot light tlnnsmission (ullmiddotis a 1-0 showlI ill figllll (I is -nthdnlto1 hut this is not stnlHlnld NtllipmPlli
Up to fhl PlPHllt lIS(middotflll pound11((1 (ulllbinntions jn lltl iOO-I11L Iunge hayc nol bllll SlClIlld 101 lhp Klpt 1-1I1l1I11PISOIl (olOlinwtll bu fnltlwl nttCl1lpti 1( )(illg IlIHd
TJIpound OF ST~lmW AFTEH HIIJ1EII Oil HHSIS rlll~CIIITTI(J
~ considl1ltiol1 of ttp lillll of Inlllling af((1 plpeipital ion of 111gt)(1
01 l(sinSTlOIll ollltionis impoltant J(jl~ thC1HI(Plltngp of light IInIlSshy
11 rshy10 f shy
09 f shy ~750 Mil- DOMINANTI
~ 08 cshy I WAVE LENGTH z
I III III i O7 - I III
~06 - 05 shyw
a
Igti= 04 - 720 Mp DOMINANT ct WAVE LENGTH- ~ 03shy
02 f shy
01 t shy 1)O~~~gt~- J 600 700 800 900
WAVE LENGTH (Mp
bull
bull
bullFIGlRt IO- COJllPIUlItiw ~IW(middottltll tlnIlRlllii-lion (II (IllP( 101 1i11(1 olllhinulloll
with dominllnl Il(lllllgths at 720 and 7iO lUi
bull
bull
bull
HAPlD PHQTQlfE1IUC JjETER~lINATION OF Rnmrm AND HEtiINi 25
mitted (spertrophotoll1eleL lCuding-) Ol light (1 (tClcrl (phOlOshyJluol01l1et(L lcndillg~) i~ StlhjNl to (hangl
]fjt~l1le 11 and l~ show that ill til( (asc ot tJaugtIllitteltllight llJHC th~ (x[llliHlllIlnl (oIHlitiOllS tllpl j lilst n dtlln-e ill Pll~(lltngl or UllllslllittnlH( follrnY(l by It ptJiml of lClntin stability with only sliuht (1111 tHn- a f(Pl a lIt1ll1btJ of minutes The light t UIllllitblllll t l(1 ill(Iln~(s This lIIay IJP llllllJltlli7P(ll1 ffl II ow 1Ilt )( f(( darI oliIII tIIlIlNlIlitt(IIIlfJIIlh (iditilIiid Ilil1 pllIipintnl )uoshyIn Of ( 8inx in (~f1( I~iUII i~ Ild stahl I 11 itlll If 1inl nh prlshyilli(ioll of 11l1d(1 II IJIX f) jllIli II (fJJltfiIIlilty slllMI IIriot 1) IIIPldUnl1i tll(I1I rllltltilJl oj tJi~ Jlt jiot IUN ilUf Jxl1 will tIt( tOWI IItlllilil I 1llIlllblJIol I ill I~11l11111 d ill till ifjuids JjOI scnttplltl light 011 till phololltHJIOIl1lttl till dilPCt ion 01 elangl b tlw IPrfIi (If that illrli(atPll rOl tlulll1Jittp(lliuht It Itlll b( llluliJr I-(Pll that if l(middotndlnJ- IIIP mad n itl I t lIP ~()ll1d()lb lpalll this pllioJ of nmiddotlatirp tuigtility tllP llLot tIOllt thi Olll(P (nil bl IPdUCld to tIl lltini III 11 Ill TIll l~adiltg (illH~ bbll Oil tlHl datn rUl lublwls and llsinlt Illl ginll ill tnhh
50 r----------------------------------------------- f shyZ
~ 40 ~----~W~A~V~E~LE~N~G~T~H~7~5~0~M~P~~~~ ~ --------------------=-=-= ~ 30 f- WAVE LENGTH 540 M~ _z _____ ___ -=- __ _ ~ ------shyt ~_=---=-=--I GUAYULEIII 20 -Z HEVEA ltt II KOK-SAGHYZ f shy
4 6 8 10 12 14 (6 18 20 22 24 26 28 30 STANDING TIME (MINUTES)
FIlirtn 11 Emmiddot of wav hll~rh Il li~ltr tlall~lIIit1alHl aftI IUIlItHt -Imlli lug 111m for guaynh llmiddotn 011111 middotiolIlJh~z 1111111 llijlitul1 flolll 1lHlh~ll1Jllryl k11II11l ~(lilltlll h~ lwitlitll 111Inu1 111l~1It1 2)1111 o1U11111 (Helillins on (illllun tlunhll IlIIJlllw]ntllW111 lutl(I[lholtllllltlt with ijUjt Wlnl IHI Ilf1 I
11 EFFEGT OF Hbli 1 -()JXT10~
Tilt lnblwl ~()h(llh pxtnl( till IPillgt ubo It 1m nllu1- bellt -~atea thut ~lll 11-111- tUP olnbhmiddot ill middottIIlIlOl ~1It tlWIIJI( my U)t PIl (tlIHatcl WIth tl1l lullh(t I tahle lJ 1hln 1- -1111 tIll (llllstlOll of nny p()~iblt tITptt of XtIIl11 diflp]lws ill ((JlllPllttUliollS of 1l-in lil lolutioll alollJ with till 1lIltbpl TIU data ill wbh +ho on tIl( hn~is of (olorilllPill ladillU thaI tll( IIUOIl1t of lnbbll Plllipirntld 110111 Ilwthyl olnlld kptOlll olntioll IJ 1li-jHlllnt 1l)04 in 1-llltlIllt ethallol)- not amlll hy thl llllNlI(l of llvin aU1ouut of llins inolution bull
-----
26 rECHNICAL BULLEfiN 920 U S DEPl OF AGRICULlUHE
100
90
80(I) C)
z Ci 70 UI a 0 60 a ~ UI ~ 500 ~ 0 I Il 40
30
A 20
0
100
90
(I) 80 C)
z Ci 70 UI a 0
60a ~ UI E 0 50 ~ 0 I Il
4-0
30
B 20
0
--
--shy ---shy---
2 4 6 6 10 12 14 16
---shy= ~ ~ shy
-
2
025 05
10
15
20
25 -30
35 40
SO
-60
=70 80
16 20 2224 26 26 30
OS
- 10
IS
20
2S
30
35 40
-50
-60 -70 -80
bull MGPE 25-ML
VOLUME
bull
MGPER 25-ML VOLUME
Florm 12-EtTld (If till1l or Slllldill~ 011 light transmittallce (01 (A) gUllyulc lnUIl(I plccipitllitd frOIll llltt h~l isobutyl Ielollt solution Ily neidilic(l ethanul bull null (B) gUllyule ll~illii pre(ipitated flom aeltoll~lllcetOlll-Cl])osolY( 3-7 solushy11011 by H(illilip(i l1U (HPlldillg~ nt -lIlillult Ifllpluls 011 Evelyn photoelectric colorimellr with jU-lllp tlllll alit U-1I11 npN(lle spp also table 2)
bull
bull
RAPID PI-IOlOMEllUC DElEnMINAlION OF RUBBER AND RESINS 27
TADIbullbull ] 4-ReZation of amiddotmount of middottbber pleeipitate(Z Oln metltlIL isobutyl ketone 80lutions by OS-pereent H 2SO in 95-pere(lIIt ethanol to umollnt of resin8 udde(l U8 indivute(Z by colorimetrio readinU8
(Rubber ami resins cnlculntcd on bnsis of amounts in 5middotml ullquuts of extract from 02 gm of tissue in a 2fllll olumo( bull
Hubucl r~cocrell whcll rcsins nddcd as IndIcated Htbbor al1dcd (pllcollt) ---shy
__________bull_________ ~_12rpcrc~15011crccllt 7511crccnt IOOpcrcent
PerCtllt ercellt Percellt Percellt Percent o o o o o) 50 250 263 252 25000 500 500 500 500 700 750 750 751 749
1200 1250 1250 1250 1250
EXTRACTION TEMPEHATURE AND TIME
Typical experiments to detllmine the time required to secure maxishymum extmction of rubber und ltsills at 115deg U Ilre sUlIlmarized in figule 13 the solvents used-methyl isobutyl ketone for rubber anrl Ilcetonylacetone-cellosolve 3-7 for resins extraction-are very eflicicnt since under the conditions indicttted maximum values were secured after 30 minutes of ext1llction The most eflicient liquid for the bath (lig 1) used in extrtlcting rubber or resins is ~ high-grade cylinder oil (S A E ~O) The sand bath and such liquids as glycerol have proved unsatisfactory
RUBBER AND RESINS STANDARDS
According to the National BULeau of Standards 1-_ lhclc Is no gellcrnlly recoglllz(d standard lIIutcrlul [ior II rubber standard] The rubber hydroCllrbon ill llifferent samples of conmlcrciul smoked sheet or pale crepe from heclI pluntlltions nries from l~ 10 04 llercent of the totul nutletmiddot the most 11Ioruble conditions Of preparation
McPherson () has described a procedure for the pLeparation of pure heve~ (Hevea brasiliensis (H B K) MueH Arg) rubber from crude rubber or latex In the absence howevcr of ~ generally recogshyn12ed stalldard for rubber hydlQcllrbon [caoutchouc (CnHUs) xJ the standard adopted was that of the relnthely pure product secured from gunyule tissue txtractiotl nccording to the Spence-CaldweU method (5) or the motlified PIOCCdUlU of Hohnes lind Haasis (p 2) The details for constructing the calibration CULes are given on page 10 Standard rubber samples apparenl-]y can be stored for a long timc under the conditions des(libed on page 10 The duplicate colorimetric lendings for glULyule rubber newly extracted by the modified SpenceshyCaldwell method were ()J2 ench as compared with US) each for the sample extracted by the same method but stored 1 years In each case colorimeter rcadinllS were made on mixtures containing 2 mg of rubber in It 25-1111 Yolume
The selection of tt suitable standurd for guayule resins presents some dilliculties Tll(~ acetone extract of gUllyult estimated on (l gravishymetric busis~ for instance proved to be variable depending on the type of tissue sampled or season of sumpling because such fractions as
COllllllunlcntion dul(lt1 Octohtr 22 11H3
28 QECHNICAL BULLEQIN 920 U S DEPT OF AGRICTTIIlURE
16~==========================115 shy
14 bulli= 13 z ~ 12
ffi II Q
10 c w 9a w
8gto () 7w a
6a w
5en III ) 4 a
3
2
A 00 5 10 20 30 60 90
14~------------------------------------------- bull13
i= 12 z w II ()
a 10 w Q
9 c w 8 a w 7gt o () 6 w a 5 If)
z 4 If)
w 3 a
2
o+B~~__~__~____________~__________~ 5 10 20 30 60 90
HEATING TIME (111 NUTES)
lllGUltE 13-lDffect of time o( lICntillg O2-gm samples of gunynle tissue with solYlIt nt llfio C on lo(OVl)ry of lllhlJer alld 1Isim Lt HlIhblL extracted with methyl isohntyllwtone B resins Cxtll1cted with aCftonyla(etonc-cellosolve 3-7 bull
chlorophyll are weighed along with the resins in the acetone extruct but are not estimated by the present photometric method (fig 0) 1he use of a diffeJent stanclttrd waS therefore indicated
bull
bull
bull
RAPID PHOTOMETRIC DETERMINATION OF HUBBIm AND HESINS 29
The resins standard selected is based on n relatively pure source of resins the rcsinous exudnte 011 the stems of guuyule plants IJldimishynary expeliments with the resi nouS cxuclate from diffcrellt gllayu Ie strains of various ages indicatc nHlt there is little YaLiation in this subshystance on the basis of Colorimct(r readings 011 2-mg aliqllots of 01shypercent solution in It 2i-ml volume (tabl( li) Expelilll(lnts have shown that the air-dried (xuclate contains 3RtOH p(Ic(nt of -volatile matter This material is l(latiyt~ly stablp ill (OlllpoBition and is npshypurpntly on ly slight ly hygroBcopic as shoWIl ill Ia bl(1 1 Tlrp Ipsinolls exudate may be jJleplpd in two wayi-i fl liSP as a stallClHld-(l) the clpan exudate is clripd iol Ghouls at ()1deg C at W indlPs of a(lIum Hnd aftclbCinOglOund ill a molfalis 1)I(spI((I intn airtight COllilinel OL
(2) tllP Cx7lclate is clissolllt1 ill a(lhllll and filtplpd PlactieaJlyall of the acetm1l is thpn lYapolntwl olt OPI a stlam or atCt hath and Ow residue is dripd ground an(( PI(sPIld as ill tllp fin lllethocl Tlwse two prepalHtlolls a1( (ompalpd in ta hlp ) 111( (((tails fOl ~t()lil1g the resins standald and (onstlllcting the calibration CUITPS alc given Oil page ]2
lAIIIg fi-CUIIIllrsoi (lJ lIr-dr(1I IIIIi 1((11 II II-()I-tr((l l(sil~ 11111111(8 of I II 1111Ie
[Colorimetric rrndill~s 011 1~I11 phulll(Iclrie eolorillJct[lr with i~()middotmll (100- to iiOIIIIl) fillcr [lnd 5-1111 lIperture preeipitantl part ofO5middotPIrctllt 10 to 5 paris of IIOj
nupliclllc(oloritwt([
nIl(lin~s (hIlSlcAg~ ofSlmillXo JrNliltlCllt of fPsiJI$ L1Xtlrlntp on 2 IIIg ofplanls fllsins (XIHIIlt~Jwr 25-1111 vol
tII1(1) 1
leflTs Various _ bull ____ bullbullbullbull 3-9 Colll)Josiltrlairmiddotltlricfl bullbullbull nf)2 002
])0____ bullbullbull _bull __ _ bullbull ~-l Composilld (ri d at n5 C in aUmiddotimh lWUUllJ for l (jOuj(ja hours])0______ bullbullbull __ bull ___ bull 3-0 COJIlpositld disso]NI in neptolll f1l1erNl fl(lf()ll( GGO i(jO (Ivaporntld olT OV(1r Stpl1l11 halh TesidlH drl(ld I1t fi5deg ( ill anmiddotinch VIl(Unlll for 0 houlS bull
middot106 __ bullbull _ Jir~c1rild_~_~_ _~_ ~_~ _ ~ ____ _ __ _ OUu GOifina_~ ~ _ ~~_~ ___ _ _fln~ ~~ ~ ___ ~ __ 6(imiddotI tiliA H)[_ ltlu bullbull i18 tisSflOabullbullbullbull__ bullbullbullbullbullbullbullbull lt10bullbullbull _ tillO llitO406__ bullbull __ bullbull __ bull __ __ lt10_ Utl2 fon591_ fo__ bull liGa oOa 406bullbull _ __ lt10bullbullbull_ li5S OM
j Ph( vnluls in Uw Inst COIUIIlIl indieatp thnt gunyulp fesinous (IIHlnt( wlwtlwr dfircl hi Yn(tlLJ1l1 wilh L~ perc(nt loss of volntllt wutl pr or tWl c1rild giVPd npproxil1lnh1ly t Iw snllw colorinwtCr rNHiing- 011 till busis of aliquot~ cOlllniuiug 2 IJI~ of flsillS lXIHlntp l)tIf 25-mI volultl( Ihil- illdicate~ thl11 Uw UITW IJ1flS~ of olnshytile mntl(f prt~(iJlitnt(d gins npproxilllntlly Uw $1II1l (oiOfirnl1tlf ftudiTlJs ns tho ftsidtw A pnlill1jllaf~middot (XIlltrinllnt indicutls thlli th VUllltill muller l(lIlSists of thl Ilrplne oil fmcl ion I5-(1Il gtnplls or rlsitlOtlS (lxudntll gnvll by stPll1U distillation nn Uefllgl of 011111 of jl(lfPlIW oil with npproximHte tilllsity (If OHIi lind lhus rrprlsll1ll( IlPIJroximllt(I~ 01 Jerccllt Of t he original weight 1hls lllrClnlage complrcs wllh 38 llltrC(ntlost by drvinI( in IICllnllJ
aSplusmnUH perceilt or orlginlll weightlosl
The wailnble illfolJllntioll on tlH (ow-JitlPllts of the gunYllle r(~shyillOllS exudate alld tl1( HeetOlIP ext act of gaylp ti~slw is sllIllmarized in this paragraph lYalttI (u) alld also Hangcn-Slllit lind his coworkshyers 16 reported that 20 percent of the resinolls exudate from gUltyulc stems is parthenyl cinnamaie (CHuOH=CHC020 11JI2r) Steam disshy
15 (OIlIJIIIIUicatioll flom A T Haai(II~l11it llId (0011(11 Calif0111 ill Tnfiitnte of Tccllllology Past(IlIJI Jhps( wOlken al Htud~ing the COTlHlitlllllts of the acetone extract and other conlltituellis of guuyule
30 TECHNICAL BULLETIN 920 U S DEPT OF AGRICULTURE
tillation of similar resinous exudate in the writers laborntory has yielded approximately 4 percent of the whole as the telmiddotpene oir fracshytion Haagen-Smit and his eoorktrs nportec1 thttt about 25 percent of the acetone extract from guayule branches is parthenyl cinnamate and 6 percent of the bark (ltortpamp-phlotm) extraet is parthenyl cinshynamate These workers fm-thcI reported that 25 lwletnt of the nc(shytone extract frolll bLllllches is a compound with the tlI1pilicaL formula CBoH400a 1 percent is a compound llwltillg at 2P to 2T5deg C and 1 percent of the extract from the ]eav(s is tl (olllpoulld nwlting at 100
to 1710 1Valtei (6) reported that 3 to -l perc(nt of the tI(eton( txtract
of leaves and flowering StPIllS of guayulc eonsists of waxlike substances soluble in olgallic soln~nts but insoluble in at(l and (on(ent1llted H 2S04 The flactions mentioned on the basis of (onHLTutle esti shymates of amoullts actually isolated tlecoullted for about H ptIcent of the totalncetollt~ so]ubles extracttd from tll( guuYllle 11 rub The other constituents ltlilaill to be i(](ntifi(d
RUBBER AND RESINS CALIBHATION CVHES
Typical culibndioll Clllves iol Iuhbpl and I(sins bas(d 011 (ldtLminttshytions made nccoLdillg to the plocCdmC outlin(d 011 pages middotb to 1G arc shown in figulPS 5 and 1+ The spCdlopliotoll1lttL en (OIOIjlllctCI readings are plottCd on s(lIlilogalitllllliC pappi ag-ail1st (Il 11IbblI (011shy
100 ~ 90
80 ~ 70 ~
z 1amp1 0 II 1amp1 IL
1amp1 0 Z
60
50
40 ~ltI 30 ~ en z ~ ltI II ~ 20 C) ~ oJ
10 o 2 3 4 5 6 7 8 9 10
RU8BER IN 25-ML VOLUME (MG)
bull
bull
bull FI(lURE 14--Ctlihration curve fotmiddot gllftYlIlc lubb01 (Hct(lings Oil COIPIIHlII tlOl1hl(
monochromator SlCClrophotolllet(r with 7fiO-11IL Illtel alld Hllp Wll ( IHlll()
bull
bull
bull
RAPID PHOTOMETRIC DETE~MINATION OF RUBBER AND RESINS 3]
centrations From a casual inspection of these CUlTes it would appeltr that Beers law does not hold Actual tests indicitted that Beers law was applicable only within a narrow range in the upper portion of the curves The analyticlil results on the basis of photornetric readings nre therefore calculated by direct reference to calibration curves or from reference tables of equivalent values bllscd on the cnlibllltion curves
Calibration curves for kok-saghyz alld heyea lI11tulltl rubbers and Buna S (GR-S Chem Gum IV Goodyear) and butyl (GR-I Standshyard Oil Co Protoc) sYJlthetic rubbers are hOWllil1 figure 15 The samples of kok-saghyz rubber were furnished by the Diyision of Rubshy
100
90 ~I) ()
z 0
1amp1 a
~ a
80
70
60
s 1amp1 ~ ~ 0 ~ KOj-SAGHYZ 0 l Il
50
HEVEA~ ~
40
100
90
~ 0 80z Q 70a Co)
a 60 ~ 0 0 x 50Il
40 ~----~~----~------~------~------~--~ o 2 3 4 5
RUBBER IN 25-ML VOLUME(MG)
FmUIlE 15-CaJiblation curves fOl kok-snghyz h(YCII Bunn S lind butyl rubb~ls (Readings on gy((yn photoelectric colorimeter with i20-lIIp filtpl and 6-ml aperture)
32 TECHNICAl BUIJLETIN [)20) 1 S DEP1 OF AGrnCUIlfURE
Iwt Plant JIl(I~t ignlioll of thi BlII(un and (1( l))(parcd according to 11( SPltI1((-Culd (]] (6) PIO(((lllll Hlpt pal( CLPPe was (xtmch(L with acetone blI()Ieit W 1I(gt(11l a ttnlldal(l
SEXSlllVllY Ol~ llETJIonS
By lip pIO((l(II11P olltlillP(l 011 ]Hlg( +n Iowa (lOOl IIIg (11 1111i(l0shygmm (gHlllllla) of 1hblI ill a 2)1111 yoltll1ll (all )(gt dltpltld Oil tltl Col(man (lohlP mOIlWhlOl1lHlOl l-I)((t 101 l1lOt 0111 ci( I ill1ilnlly 001 mg of Iublwr ill a 2J-1ll1 n]ulllP Illay bl Ilad Oil till EnI)1I photoshyllectlie (O]oLillllt(I Thll ya lllll- 011 tilt IHl-i- (J I (xl ad iOI1 fmlll 02 gill of til-lI tH(JI(lillg to tllP -lllndal(l jll()(pdull 1(PIPStlIt IlO()2J tlnd 002) P(IT(lIt of llIbl1ll IPI)(((inly bull1t1lollgh -lI1t low allils can be d((d(middot(1 il lIoullt1 Ill IPtllizpd thnt till PIIOl ill PlI(Plltng( or tll( al110unt dltlIllIilll(J i ltlatlpl high ill tili PIY lo Itlllgl 111 aetllllllladie(middot Ill( lopl lillliL 111)(1(1 lIw (ollllil ions of tlil ]lI()(lltlIIIl u ol1tlinpd ipt at l11 11I1 or 1111gt11(1 illt i-1ll1 Ollllll IlPIPltPlltillg 01 p(gtl(pnt of JllUiJtL un tlll 1Hli or (xlla ion rlOI11 II rlll of tisSIll
EIlIlOH COSIIlIHIIO
In Oldpl to H(IIp ill )1lHtPltt pl((iioll illlpIi1I- it i lH((SSHI to slnlldHIdiz(i rigidly 111( Pl()((dlll( 0 illdi(ntpd Oil pnglt- - to J( If lids i dOlH tlip lXIHlinwnlal PIIll is t(middotdllld 10 n ndninlllill
Illlt pl(iioll of (hI ]lIPPllt 1IHllwd Oil til basi of ]llllP llIllJt1 alld Ipsinssollltions call hI jlldgl(J 110111 figllll Hi lileh lio- til HPIlIgl d(intioll oft -illgIP lI1lnSIlIlIIIlnt in lHi((lltagl of Ill( alllOllllt 01 Illhshy1)() 01 lpsins d((PI1I1 iJlld TIl( (1101 PlI(Plltaglt H1( gi (1 101 OJ) to
RUBBER IN 25-ML VOLUMEMG) 004 01 02 03 04
i= I I IZCtOW
fbA ICtU CtCt WW a
01 02 03 04 05 06 07 08 09 100 = RUBBER (PERCENT)
RUBBER IN 25-ML VOLUME (MG) 10 20 30
~ I CtZ
bBOw Ctu CtCt Ww o I~
010 50 100 150 200 250 RUBBER (PERCENT)
RESINS IN 25-ML VOLUME(MG) 10__ __3-0_ 40 50 60 70 60 90 100--_-- 2_-0
Ct~ -r- 1 I OZ
WCt UCt b C wCtW
a o I I 150 250
RESINS (PERCENT) o 10 50 100 200
bllI 1tI W-Yllnl dtd1 ioll I I 11l1 11IlI11 1(111(11 1 III Plll- IlIIIlol1 01 IIim~
bull
bull
bull solution Il basis J o golH of tiSSII (JlILCl-nt (11(11) for (~I) (l)1 til O 1I1
of luhllpl lin 1 III I (I Ill of lUhlJPl nllll laquo I J to 111 nlg of IlSlllgt (Itllillgs on ]iYllyu pllolwh-llrk CO[IJlilll(-(PI with nOHIP Iiltlr lIntl U-lIll allcrture)
RAPID PHOTOlJElRIC DELEHlllNAllON Cn HUBBER AND H1~SINS 33
10 mg of rubber anel1 to 10 mg of resins in a gJ-m1 yolumC For
bull
bull
bull
comparative ptuposes the leslllts arc also calculated on the basis oJvershycentage rubber OL tltsills in 02 gllI of tissul As WOlllL be expcet(d the error increases sOIlHgthlf for 1(lali nmiddotly low COlHell t1llf iOlls oj rllbbeL or resins The curves in figure 1(j s1l0 that ill til(gt Illlge Ol to 10 pCrshyeent of lubber the elTOI rangts Jroll1 abollt Ll to II) ]IlC(lIt abo(~ this mlllc tIlt (ITOl d(((ts(s to (ollsidlItbly ltmiddotss (han 1 1lICPllt of tlH mllollnt ltl((Lmill(d Hil1lilally in tlH (lISl of l(sins analysis (fig 10) the ltLTor is (onsit1eIubly INS than 1 PlLllnt ill (he lallgp of 11 t~) ~() penPII t
In nil ([lSl of lllhblI alld (sins lx(Inltpd tIOIl1 (issups Ol addcltl to tisslle lxtlads (s(( tabhmiddots (i H) illyolillg ll01P o(lllntiolls the eLI01
is hig]wl thun that indilHtld in figllll ((j Im pUIl Ill )])p I tllllllsins solutlOII
COlllUCIIOXFOH IXSOLl-IlLl~ Ilgsqgt(Jg
111 th( Jllo(pdulP ollllillPd 011 paw I till illsolllhll isSII Ipidll( tflpl (xttlw(ioll is (Ptill tlw lIask l(lll till xtlct i l1wdp up to yoltlllH It is not rOllPllipnt (0 IPt()PI qWlIltitati(Ir III(lw[olH a 11(1 pllooll extlnlfs of guuyull I is-lll alll thl1l main t11l111 up (0 YOIUllllmiddot bpCaUHI sllch all additiollal stltp wottld]) tillll-C(JllS11ll1illg Th( Iogiea nll(gtIshynntin is to mnkp tltl lXtlUCt Llld Ipsidup lip to OllillH in till original flask andi llPSStllY 10 llwlno tl OIIpdioll wlHIl (allIlnting [hc llshy
Hults f(JI [hl oll111lC displupd hy till ins()lllbh llsidll( III it l)picat (IXpednHllt (ollsisting of Jhp lppJiea(iolls if was Iollnd llftt at ~iiO ( 02 gill 01 Iuhhll pillS IPill-fl(( lisslI(gt (lollpdll fot llwistUlC ou basis of dlyillp ut lOW 101 ) llOlll-j (lbp(ld only t~ llllUll voiul11P of OOk7D~- OO(lOO(i Ill of lllthyl bolnl(yl 1lIOll( (lplhlli(al-t(Tnltle sp gl () Ii I ll(Hli (j at ~)) -gtitllP tl1(gt 1It101111( () r t is-lIl xt Iadld j sl1lall til( PlIOI dul to Ill(gt insoll1blp Ip~idll is slllall III [0111 ill( wOtk it (all lJp diIpgal(ll(l
]hcon~lIY OF HllIllgl AiO HESIS AIH)gl) TO EXTlIACI OP
GlYlLE TISSlg
Tnl)ll G L(IHpslntillp (ypi(nl llld(~ SllOS (hat all a plngl of HIOK PlI((nt ot lltl pltl( Ilhl)(l acldpd to tllP Itll h iolJut1 InmiddottcJllP xhnet
of guayulp tiSI1( WllS 1l((PllIl Tlli nllintioll flOlll (olllplpU I((OYshy
PIY i within flll pxp(IiIlHuttllIIOI ~illli]llly fnbll Ii llows thn 1111 llYlIUgl of 1O(1~ ])(I(Pllt of gllllYllII 1(-i1l- add(d to II( (pllosol( (xshytrae of IUllY]l t i~HI Is 1l(oPIPI
THl~ (~ Hf (Off Ill of 1111)( J OJ I~il~ lItfI(( In ~(JI1IJk~ Ilf (111 [lI1Il fI2 lIII
0 tlUfllllit i~~I1
Instrument
---- ----~---- bull shy 1(1
Colemun ruono~ltrOUlllt()r 2t) II sJl~ctroJlhOL()lIIeter with 2tJ I iflllllI wnclength Fetting 21 II nntl 0-1111 WU HI hUJl(L _ L U
Ill 7Evolyn photo~lcclrie (olor JU [ imctcr with iO-llIl filler IV (I
H1 0 t I I
llImiddot lUn WII 1011 HIO Wn mil lUulon
10 JIg1111 IUI ml lUl anh Io aLn 111)_I ) III li lU It 2) deg wn2SU DD
Irl JIll II IIr II US II
1110(1 lULa lUI IlK) IJ WU
I( llI Htl tNI 1(111 2tlNI HI 0 221) lllil t2S 0 1~ 10 1~13
In (I 2117 I
10U 1l(J ~ 4 _H_j ___
9middotJIlJ5 10115 10 00 lUU5 flUU 4li (tl03 9(11)
leIlKl 1l~)5 lOOU l1KIr JOIS un 003 OIl Ii
34 lECHNlCAL BULLErIN 920 U S DEPT OF AGRICULlURE
COMPARISON OF PHOTOMETRIC A1D MODJIoIED SPENCE-CALDWfLL METHODS OF RUBBER ANALYSIS
Guayule samples were analyzed by the photQ111etIic method and by bull the modified Spenc(gt-Cnldwell mcthod The values in table 7 represhyselltativ(I of typical results indieate It -atisfactory dcglpe of conformshyjty between the two methods in thl range of tiSSlHH with llHHC than OJ) percent of rubbtImiddot On the bnsis of the amounts determimd the results in this runge for the plmiddotts(nt lIlcthod ayernge apploxinHltely j percent highcr
~LAIII~ 7-(oIllJl(i~on of lltlllrIic (IIri mOtllinl SJl(II(r-(ulri-wall IIIrtlwrl~ of rlrrlIIillillfl 11)1)(1 COIIrll of UI(III
1 Flowers frllm amiddotmonth-oltl nursery plants
YAIIIATJO- OF SIli(LE DETEnt1NATIONS Fnoll TnEIIllIEAN
Rllbbel (Uall8i8-Thc plcCision of thc pLcsent method when gunyule tissues Hr( nnnlyz((1 for rubber may be j udg(d flom I Ill datil presentcd in table H TIl(se dahl -how that thl pplCPlltag( uriation of single determinatiom from nwan yullles with low standllrd enolS ranges from less than 1 to 4 p(gtrlent
R(8in~ wWlsi-r-s lndi(a((1 011 page ~j he INntlts s((uled hy the present phoolllttric nsins llHt hod are not tliltly (olllpalable with those of the grtLVimetri( ncetol1l-cxtlt1(tioll II1etho(l Thjs made it necesSllry to selc(t another lalibllltion staudud-tlll Ipsinous exullate from gullyule shrub-thut gies relatively COllstlllt photometric readshyings (table 5) The resin (olltents of guayule roots branchcs or leavcs usually ran(~e from about) to 1-1middot pelcellt The ple(ision of the present methotf WhCll gUHyule thslllS lIe analyzed for reins may be judged from the datalHmiddotpscllted ill table 9 1h(se data show that the p(lcelltage variatiun of sillgle lhmiddott(Lminntions iLO11 meun ynlnes with low standard NTOrs rangcs from about 05 to 4 percent
bull
bull
bull
bull
bull
RAPID PHOTOMETHIC DElEruIINAlION OJ RUBBEH AND HESINS 35
IAIILE 8-luriation inclieute rubller (mallSM of [1wIIle tissue bll thc 1111O0Illclc metwII
Vnrlntlon~Ilbher I (rom mean
ierCtnl Percelll ~OU -22 ~ 25 +27 ~ 20 +18 ~UO -22---------1_______ 51110 0G6 bullbullbullbullbullbull _bullbull
10 ro ----=ii41075 -01 1000 +11 1010 +13
rlln HI itil 1l9~ 1_ ___ =-~~~
115511 ~ US -111 III II 1575 -13 115 b tiS -I a 111 h WlU +22IIM-(middot bull 11K -1Ja Illi c 1000 +03 1J5H1 W +l)7 ll1imiddot tl 1575 -13
Mcnn 15951 131
1102-11 21fJ() +21l102-h _ ~~)SO -17 1102-c bullbull 21CO +21n02middotd ~OIiO -26
2 r~plusmn Il~ 21151 261 I -~-------bull---__ _~~_~______l-___--_
1 lhe$ 1111($ I1n (or SlIlIIllltS Stpnnltplr PHrilClld IIrtlrdlng 10 1hr prollIlIlr( OIiIIiIl(o(I on Imgt$ 4 to IC ~tcond nUlI1 hlr r(J)[ltnts stl1ndnnl llrrot of tilt 1I1(1111
1_1l1~ n-J(lri(iot in relli(Upound rpoundsins (lllalIsfs of VIOJII( lixsue b1 the lhomillric lII(lloli
-- ---~--- - __-------- shybull I I I I Varlgttton
_________~___ ~~lu_n_Jl_Q_~~~_____ ______I__~_o~S_J frOID lDean
Percent Percentgt458-1 ~65 +41IWtl-li 130 -a2Hli8c aliO +26S41i8-d bull 130 -32
1(-011 34I10Olifgt __ bullbull __ ~--====
li-9~2n 881) -06 li-9~2-b Si5 o ~HH2middot(middot S i5 -6$-H2middotd 000 +1
8851 054
O i5 +6 9 i5 +6 950 -20 U75 +6
H-liG3o-n bull -1 n-li6~b bull __ _ -IH-IWH +4H-l61511 bull -1
1tmiddottlU
62~-lI __ 62~-b ij24-( bull OH-Ji
(-Ull
I rll(St oluls nre tor separately ~xlrflCled SllllllllCS IlctOrdlug lO procedure outllned ou pages 4 to 10 i Secoud number r~prtgeulS stulldMd error of lIe menn
36 TECHNICAL BULLETIN 920 t ~ DEPT OF A(]RICCLTCRE
ReUUER A~ALYSrS I~ CRCOE-RcuUER PROOCCTS
Sew rapid photometric m(lthod~fol the ddellllinttion of rubber and reii Hi ill uaYllp ti--ut htp lllell pIPHnl pd oil pag( ~l to In A brief H1111111tlY of It similar rnpid llHthod fm 1I1hb~rllnltlysis of u1lulcanizNl tlIldp lubbll pl(Hlmtlt whielt i~ bn-(tldo on the prill o
ciples dehtilcd tlllLe follows Duplltate nt-gm sllmph of the finely cliyiliNl IlInttlitiup wlirllll out [~ei-()l (all hl lIf((tinmiddotjv INd to lt1iyidl till alllpl) TIll kltolll-olubll portion of till )111(11( tlrc di-olved a- indh-Htpd fot thmiddot lllnkill~ of -tlllHlunlluhhll olutiou Oil Pt 1II hut tIl IUlIp Hn lIn l-fplImiddotd 10 lHI-ml rolllllltti( fln-k antil1ltld(lup to Olllll1l The bnlulUp or till JllO(ldllll i- thatutlilllll on paWs -1- 1 IHI Ii 111( 1(111 1- nIP IXPIP--pd nil til IHi or Iw oligiJla w(lullt of I Ill (I11l1p-I1l11Ilt1 1)(0(11(1
Hupitl PlllimiPJojgtiWllllllllh llIltllOd~ fOJ Ihl llPtlmiddotminntion of ImiddotUlJbll tlnd 1(-illo- ill -111111 Illllph of gutlYllll tiUl IIll dl-eli)ed 111() IlltlY d~o Ill nltlI1lld fOl III Iwl Illhlwl- and l~iJlmiddotb(lLiJlg plant TIllt l[Olllhup hns nlo b(l1l ntuptpl fot IIH lltlIll1illtltioll of lllhbpl ill 11lHhrublwl Pl(Jdlld~ HIIl 1111 hI ndaptld JoJ IIll ann lysis of ynt1J(gt( ic lllbbl[- The llllthmb HIP 1gtn(11 fill tIll fol1owill plimiph- III Grinding
tIll PIOPlly driPl t i~lIl 01 Ul tillg tIll pnHhHt to tll l((lllilllllh~lel of filWlH-- til plllllit qIHlIllilnth( lXIIHtioll 01 IIlbhlI 01 1(--IJl- () llsing oXWllutld olnuh (kttoJls IIt(talp and() fllltil for LIbbel and IH(ltIlIlyptIJllIllIoolYlnJld-o flJllh 101 niJlsl with t(lathelr high IlPililig points 111 to n C) l]olle or in mixt tIll thllt Pll mit tlll rnphllxututioll of luhll(l OJ [middot(ill ill ~() to (l mi1lutp It r(latiwly high 1lllIllllltlltP Ill to 1~11 ) l) lllllipitntillu till luhblI OL Imiddot(ill frolll aliquot () f till oltn ion I IlIlllI-i () f Hlltabhmiddot pl(~(i]litallt (willifhmiddotd lthmwl fOl IIlhlHI Hild llitlifild lllr fOJ JP-illl t~) IIlHkillphotollllliilPIIIIiIlof PlllPlltal of liht tLaIlS mittUl(P lIftlI IlIlbll (II Il in PIlipitalioll 11 II WI( Iplllh thnt (limiJlall till PIIOl dill 10 xtralllOlh (0101 (till dptl1minntinll Iph jill 011 tIll dtwlopllIlJIl of H HIli rOI1ll tlllbidity 111 hpl than I (olot rI
jJlIlpOP-ofallnlyi-I ( p(lllil1thb IIllijOI1ll turbidity or 1llt[lIinmiddotd d(ltl of jgtIp(ii(JlI l)~ lIltlkillU tIl plllltollllmiddottri( ntdillU al tandinu tiJlH~ (dlllilll wlli(h IhlllH(lill-- IP 1llutinmiddotly tnhll) t1ll1t an hlsl~1 oil the (oJlItlIlllItion of IIlhlHI Ill I(ill (lIPIipitat((L
TIll -I(p ill till jll()(Plhul HIP 1-- follOylt (1) 1l~UIIL uJ1lplls of thwl UJfJlllHl (II tliddl(l HUt dlipd 11Illtplial an lXIllltel with11 Ill of till nlnll ill t (oU tlllltIPlll[gtPImiddotatlup oil Iath at 11 Cbull fol 11 minutl I) iIP1lIin(middot(lohd til( (XUtllhllll Jltldl lip to It middotml ynlmlll til( (nlifild by (Illlifllgiuu HlId thlPl IlI nliql1ot of tIl (IalioPlllxUlltl nll Uillltlmiddotll(t to l-llll OIlIIlIllril fiuk- (1) For a trial Ilnditlg 0111 III tlll j liJmiddot~t IllHII IIjI to Ohlllll with lilt Pll shy(ilitnnl a 1(11 it 111 (Dod fill llli lIut ( ptotoJIIltlil IPtlllillg-- of pllllntnl or liuht tlUtllIlillal(I oil n (lpel OphotnJlllllI at rase hng-tlt (If 11 llJ Ill Ol It lollllil1lPtImiddott lloyidld with tIll P10]11 I 1110110shy
Ihlolllltt hmiddot Ii1llI Olllhi lIatioll for -1IpItillg UJlproXilll1l tply Wtl P ]Plwth )0 mp are HHlltk TIll Illldillg lliJtaillld fol tIlt 4-milutl tliall(~ll-
bull
bull
bull
RAPID PHOTO~IETRIC DETERIINATIOX OF R(BBER AXD RESINS 37
ing are referred to a table of equhmiddottllut~ previously p1(pa1elt1 on the
bull basis of 4-minute reac1inJ~ for tilE nmge of lot1telltlatiol1- of rubber or resins to bE elHOlll1t(led tmd gidn thtmiddot -tnnlillfr tillIP fill rUbbEt or resins aiter prE(ipitlltiol1 lwfolE photoIllNliI j(tltlill1 un IUade The r(middotnmining dllplllatt aliquot lll then HHllil up te ol1l1Jle and lpoundadillg ale marle ut the -tandillfr tiUlE iudklltll ill rhl tall1lmiddot for the final r(adillg~ -1) 111( milli1lnm or p(tCPlltllt- of lllhbpL (II 1(-in pr(s(nt are rpadholU a prlpan(l table of lquiltlput for tlll photoshymetric readings h1~l(l ill pnell e1-E on pxpPlilmlItal lhln 1111(1 u-ing as stimtlltlds pure luhbll in 1l1bbtl milllYb aIHI guaYllh ll-ill- lxIHlatt~ in resins detNIl1111lttion I
LlTERATlRE CLTED
(1) lUnSbull 1fl36 THE mURMIXTIOS IIF IOTA RE I III OOl THER llT~II
F1 bullrol IlY U(T1l0fll UfSlfi ~rrnrl r flm lt1 KEYS TI Bill Chern 114 44J-l59 illns
t1 ~ICPHHlObullbull T 1J3bull~ lUTHOO roa THE PtRInCAnu Or a(lIUl IRrIlHU It of TIn
PLRIHEU Htllllflt [ i Bill lallllall 111 Rmiddot 711middotj iIlus
I ) RHBERG P B Ul5 A METHIlO Or ~u(ronrll-nl Hi tIII rUIl[1 f71 ii illlI
bull 14 Hoss W flbull and HARDESTY J O
llH IR1ltDII Of HfITilIZfmiddotR DllIJS ltt 1 Yl fll Off gI bern JIIIlI i ~middotmiddotlf IIl
101 SPEltCE D nnd CuoWELr ~I L 1933 DETER~n-ATIOo OF RtBBER Ii nrllllpoundRBfR Iusr 1uI II1 amI
Em~ifl cttIliIa~~ r Ell i 71middot7i l11 (HI WALTER E D
1U44 ISO~nlS OF PRTlltSrr 1trHpoundV bull l UI n W lHHt (Tnmiddot 1ETS FROM GiYI l~iIl lItr Clttrn SII J UI titJ middotn9--C1 ilIu
17 J YOEbullbullr H lO~( roLORIlETRT 771 IPmiddot nl -W Yurk f H Plrwptric hmica
naly-II rimttry lUll XphHHlnmiddot~ y 1 1
11
HI) ~ fPHELolzTRf 57 111bull Lin xw Yk t H lt PhmeHt CblUlmiddot ila AnaiY~l~-(H lithrry and XIhmiddotILpfIY Y wirh enomiddot rrJlllrjr hy H KtlJnJU11 I
t~1I --- and ~ARVER L 1f41 nlua-w ~in L liLhr IS IP ll~ XIW Yrk
bull For-sale by th~ ~a~fr1nt~nf1ent Dt~c~~ogtnts-~ s t1i rArnn~ut Pn~~~ tJffieshy
Washington 5 D C bull Pl lU ~nts
bull
bull
bull
HAPlD PHQTQlfE1IUC JjETER~lINATION OF Rnmrm AND HEtiINi 25
mitted (spertrophotoll1eleL lCuding-) Ol light (1 (tClcrl (phOlOshyJluol01l1et(L lcndillg~) i~ StlhjNl to (hangl
]fjt~l1le 11 and l~ show that ill til( (asc ot tJaugtIllitteltllight llJHC th~ (x[llliHlllIlnl (oIHlitiOllS tllpl j lilst n dtlln-e ill Pll~(lltngl or UllllslllittnlH( follrnY(l by It ptJiml of lClntin stability with only sliuht (1111 tHn- a f(Pl a lIt1ll1btJ of minutes The light t UIllllitblllll t l(1 ill(Iln~(s This lIIay IJP llllllJltlli7P(ll1 ffl II ow 1Ilt )( f(( darI oliIII tIIlIlNlIlitt(IIIlfJIIlh (iditilIiid Ilil1 pllIipintnl )uoshyIn Of ( 8inx in (~f1( I~iUII i~ Ild stahl I 11 itlll If 1inl nh prlshyilli(ioll of 11l1d(1 II IJIX f) jllIli II (fJJltfiIIlilty slllMI IIriot 1) IIIPldUnl1i tll(I1I rllltltilJl oj tJi~ Jlt jiot IUN ilUf Jxl1 will tIt( tOWI IItlllilil I 1llIlllblJIol I ill I~11l11111 d ill till ifjuids JjOI scnttplltl light 011 till phololltHJIOIl1lttl till dilPCt ion 01 elangl b tlw IPrfIi (If that illrli(atPll rOl tlulll1Jittp(lliuht It Itlll b( llluliJr I-(Pll that if l(middotndlnJ- IIIP mad n itl I t lIP ~()ll1d()lb lpalll this pllioJ of nmiddotlatirp tuigtility tllP llLot tIOllt thi Olll(P (nil bl IPdUCld to tIl lltini III 11 Ill TIll l~adiltg (illH~ bbll Oil tlHl datn rUl lublwls and llsinlt Illl ginll ill tnhh
50 r----------------------------------------------- f shyZ
~ 40 ~----~W~A~V~E~LE~N~G~T~H~7~5~0~M~P~~~~ ~ --------------------=-=-= ~ 30 f- WAVE LENGTH 540 M~ _z _____ ___ -=- __ _ ~ ------shyt ~_=---=-=--I GUAYULEIII 20 -Z HEVEA ltt II KOK-SAGHYZ f shy
4 6 8 10 12 14 (6 18 20 22 24 26 28 30 STANDING TIME (MINUTES)
FIlirtn 11 Emmiddot of wav hll~rh Il li~ltr tlall~lIIit1alHl aftI IUIlItHt -Imlli lug 111m for guaynh llmiddotn 011111 middotiolIlJh~z 1111111 llijlitul1 flolll 1lHlh~ll1Jllryl k11II11l ~(lilltlll h~ lwitlitll 111Inu1 111l~1It1 2)1111 o1U11111 (Helillins on (illllun tlunhll IlIIJlllw]ntllW111 lutl(I[lholtllllltlt with ijUjt Wlnl IHI Ilf1 I
11 EFFEGT OF Hbli 1 -()JXT10~
Tilt lnblwl ~()h(llh pxtnl( till IPillgt ubo It 1m nllu1- bellt -~atea thut ~lll 11-111- tUP olnbhmiddot ill middottIIlIlOl ~1It tlWIIJI( my U)t PIl (tlIHatcl WIth tl1l lullh(t I tahle lJ 1hln 1- -1111 tIll (llllstlOll of nny p()~iblt tITptt of XtIIl11 diflp]lws ill ((JlllPllttUliollS of 1l-in lil lolutioll alollJ with till 1lIltbpl TIU data ill wbh +ho on tIl( hn~is of (olorilllPill ladillU thaI tll( IIUOIl1t of lnbbll Plllipirntld 110111 Ilwthyl olnlld kptOlll olntioll IJ 1li-jHlllnt 1l)04 in 1-llltlIllt ethallol)- not amlll hy thl llllNlI(l of llvin aU1ouut of llins inolution bull
-----
26 rECHNICAL BULLEfiN 920 U S DEPl OF AGRICULlUHE
100
90
80(I) C)
z Ci 70 UI a 0 60 a ~ UI ~ 500 ~ 0 I Il 40
30
A 20
0
100
90
(I) 80 C)
z Ci 70 UI a 0
60a ~ UI E 0 50 ~ 0 I Il
4-0
30
B 20
0
--
--shy ---shy---
2 4 6 6 10 12 14 16
---shy= ~ ~ shy
-
2
025 05
10
15
20
25 -30
35 40
SO
-60
=70 80
16 20 2224 26 26 30
OS
- 10
IS
20
2S
30
35 40
-50
-60 -70 -80
bull MGPE 25-ML
VOLUME
bull
MGPER 25-ML VOLUME
Florm 12-EtTld (If till1l or Slllldill~ 011 light transmittallce (01 (A) gUllyulc lnUIl(I plccipitllitd frOIll llltt h~l isobutyl Ielollt solution Ily neidilic(l ethanul bull null (B) gUllyule ll~illii pre(ipitated flom aeltoll~lllcetOlll-Cl])osolY( 3-7 solushy11011 by H(illilip(i l1U (HPlldillg~ nt -lIlillult Ifllpluls 011 Evelyn photoelectric colorimellr with jU-lllp tlllll alit U-1I11 npN(lle spp also table 2)
bull
bull
RAPID PI-IOlOMEllUC DElEnMINAlION OF RUBBER AND RESINS 27
TADIbullbull ] 4-ReZation of amiddotmount of middottbber pleeipitate(Z Oln metltlIL isobutyl ketone 80lutions by OS-pereent H 2SO in 95-pere(lIIt ethanol to umollnt of resin8 udde(l U8 indivute(Z by colorimetrio readinU8
(Rubber ami resins cnlculntcd on bnsis of amounts in 5middotml ullquuts of extract from 02 gm of tissue in a 2fllll olumo( bull
Hubucl r~cocrell whcll rcsins nddcd as IndIcated Htbbor al1dcd (pllcollt) ---shy
__________bull_________ ~_12rpcrc~15011crccllt 7511crccnt IOOpcrcent
PerCtllt ercellt Percellt Percellt Percent o o o o o) 50 250 263 252 25000 500 500 500 500 700 750 750 751 749
1200 1250 1250 1250 1250
EXTRACTION TEMPEHATURE AND TIME
Typical experiments to detllmine the time required to secure maxishymum extmction of rubber und ltsills at 115deg U Ilre sUlIlmarized in figule 13 the solvents used-methyl isobutyl ketone for rubber anrl Ilcetonylacetone-cellosolve 3-7 for resins extraction-are very eflicicnt since under the conditions indicttted maximum values were secured after 30 minutes of ext1llction The most eflicient liquid for the bath (lig 1) used in extrtlcting rubber or resins is ~ high-grade cylinder oil (S A E ~O) The sand bath and such liquids as glycerol have proved unsatisfactory
RUBBER AND RESINS STANDARDS
According to the National BULeau of Standards 1-_ lhclc Is no gellcrnlly recoglllz(d standard lIIutcrlul [ior II rubber standard] The rubber hydroCllrbon ill llifferent samples of conmlcrciul smoked sheet or pale crepe from heclI pluntlltions nries from l~ 10 04 llercent of the totul nutletmiddot the most 11Ioruble conditions Of preparation
McPherson () has described a procedure for the pLeparation of pure heve~ (Hevea brasiliensis (H B K) MueH Arg) rubber from crude rubber or latex In the absence howevcr of ~ generally recogshyn12ed stalldard for rubber hydlQcllrbon [caoutchouc (CnHUs) xJ the standard adopted was that of the relnthely pure product secured from gunyule tissue txtractiotl nccording to the Spence-CaldweU method (5) or the motlified PIOCCdUlU of Hohnes lind Haasis (p 2) The details for constructing the calibration CULes are given on page 10 Standard rubber samples apparenl-]y can be stored for a long timc under the conditions des(libed on page 10 The duplicate colorimetric lendings for glULyule rubber newly extracted by the modified SpenceshyCaldwell method were ()J2 ench as compared with US) each for the sample extracted by the same method but stored 1 years In each case colorimeter rcadinllS were made on mixtures containing 2 mg of rubber in It 25-1111 Yolume
The selection of tt suitable standurd for guayule resins presents some dilliculties Tll(~ acetone extract of gUllyult estimated on (l gravishymetric busis~ for instance proved to be variable depending on the type of tissue sampled or season of sumpling because such fractions as
COllllllunlcntion dul(lt1 Octohtr 22 11H3
28 QECHNICAL BULLEQIN 920 U S DEPT OF AGRICTTIIlURE
16~==========================115 shy
14 bulli= 13 z ~ 12
ffi II Q
10 c w 9a w
8gto () 7w a
6a w
5en III ) 4 a
3
2
A 00 5 10 20 30 60 90
14~------------------------------------------- bull13
i= 12 z w II ()
a 10 w Q
9 c w 8 a w 7gt o () 6 w a 5 If)
z 4 If)
w 3 a
2
o+B~~__~__~____________~__________~ 5 10 20 30 60 90
HEATING TIME (111 NUTES)
lllGUltE 13-lDffect of time o( lICntillg O2-gm samples of gunynle tissue with solYlIt nt llfio C on lo(OVl)ry of lllhlJer alld 1Isim Lt HlIhblL extracted with methyl isohntyllwtone B resins Cxtll1cted with aCftonyla(etonc-cellosolve 3-7 bull
chlorophyll are weighed along with the resins in the acetone extruct but are not estimated by the present photometric method (fig 0) 1he use of a diffeJent stanclttrd waS therefore indicated
bull
bull
bull
RAPID PHOTOMETRIC DETERMINATION OF HUBBIm AND HESINS 29
The resins standard selected is based on n relatively pure source of resins the rcsinous exudnte 011 the stems of guuyule plants IJldimishynary expeliments with the resi nouS cxuclate from diffcrellt gllayu Ie strains of various ages indicatc nHlt there is little YaLiation in this subshystance on the basis of Colorimct(r readings 011 2-mg aliqllots of 01shypercent solution in It 2i-ml volume (tabl( li) Expelilll(lnts have shown that the air-dried (xuclate contains 3RtOH p(Ic(nt of -volatile matter This material is l(latiyt~ly stablp ill (OlllpoBition and is npshypurpntly on ly slight ly hygroBcopic as shoWIl ill Ia bl(1 1 Tlrp Ipsinolls exudate may be jJleplpd in two wayi-i fl liSP as a stallClHld-(l) the clpan exudate is clripd iol Ghouls at ()1deg C at W indlPs of a(lIum Hnd aftclbCinOglOund ill a molfalis 1)I(spI((I intn airtight COllilinel OL
(2) tllP Cx7lclate is clissolllt1 ill a(lhllll and filtplpd PlactieaJlyall of the acetm1l is thpn lYapolntwl olt OPI a stlam or atCt hath and Ow residue is dripd ground an(( PI(sPIld as ill tllp fin lllethocl Tlwse two prepalHtlolls a1( (ompalpd in ta hlp ) 111( (((tails fOl ~t()lil1g the resins standald and (onstlllcting the calibration CUITPS alc given Oil page ]2
lAIIIg fi-CUIIIllrsoi (lJ lIr-dr(1I IIIIi 1((11 II II-()I-tr((l l(sil~ 11111111(8 of I II 1111Ie
[Colorimetric rrndill~s 011 1~I11 phulll(Iclrie eolorillJct[lr with i~()middotmll (100- to iiOIIIIl) fillcr [lnd 5-1111 lIperture preeipitantl part ofO5middotPIrctllt 10 to 5 paris of IIOj
nupliclllc(oloritwt([
nIl(lin~s (hIlSlcAg~ ofSlmillXo JrNliltlCllt of fPsiJI$ L1Xtlrlntp on 2 IIIg ofplanls fllsins (XIHIIlt~Jwr 25-1111 vol
tII1(1) 1
leflTs Various _ bull ____ bullbullbullbull 3-9 Colll)Josiltrlairmiddotltlricfl bullbullbull nf)2 002
])0____ bullbullbull _bull __ _ bullbull ~-l Composilld (ri d at n5 C in aUmiddotimh lWUUllJ for l (jOuj(ja hours])0______ bullbullbull __ bull ___ bull 3-0 COJIlpositld disso]NI in neptolll f1l1erNl fl(lf()ll( GGO i(jO (Ivaporntld olT OV(1r Stpl1l11 halh TesidlH drl(ld I1t fi5deg ( ill anmiddotinch VIl(Unlll for 0 houlS bull
middot106 __ bullbull _ Jir~c1rild_~_~_ _~_ ~_~ _ ~ ____ _ __ _ OUu GOifina_~ ~ _ ~~_~ ___ _ _fln~ ~~ ~ ___ ~ __ 6(imiddotI tiliA H)[_ ltlu bullbull i18 tisSflOabullbullbullbull__ bullbullbullbullbullbullbullbull lt10bullbullbull _ tillO llitO406__ bullbull __ bullbull __ bull __ __ lt10_ Utl2 fon591_ fo__ bull liGa oOa 406bullbull _ __ lt10bullbullbull_ li5S OM
j Ph( vnluls in Uw Inst COIUIIlIl indieatp thnt gunyulp fesinous (IIHlnt( wlwtlwr dfircl hi Yn(tlLJ1l1 wilh L~ perc(nt loss of volntllt wutl pr or tWl c1rild giVPd npproxil1lnh1ly t Iw snllw colorinwtCr rNHiing- 011 till busis of aliquot~ cOlllniuiug 2 IJI~ of flsillS lXIHlntp l)tIf 25-mI volultl( Ihil- illdicate~ thl11 Uw UITW IJ1flS~ of olnshytile mntl(f prt~(iJlitnt(d gins npproxilllntlly Uw $1II1l (oiOfirnl1tlf ftudiTlJs ns tho ftsidtw A pnlill1jllaf~middot (XIlltrinllnt indicutls thlli th VUllltill muller l(lIlSists of thl Ilrplne oil fmcl ion I5-(1Il gtnplls or rlsitlOtlS (lxudntll gnvll by stPll1U distillation nn Uefllgl of 011111 of jl(lfPlIW oil with npproximHte tilllsity (If OHIi lind lhus rrprlsll1ll( IlPIJroximllt(I~ 01 Jerccllt Of t he original weight 1hls lllrClnlage complrcs wllh 38 llltrC(ntlost by drvinI( in IICllnllJ
aSplusmnUH perceilt or orlginlll weightlosl
The wailnble illfolJllntioll on tlH (ow-JitlPllts of the gunYllle r(~shyillOllS exudate alld tl1( HeetOlIP ext act of gaylp ti~slw is sllIllmarized in this paragraph lYalttI (u) alld also Hangcn-Slllit lind his coworkshyers 16 reported that 20 percent of the resinolls exudate from gUltyulc stems is parthenyl cinnamaie (CHuOH=CHC020 11JI2r) Steam disshy
15 (OIlIJIIIIUicatioll flom A T Haai(II~l11it llId (0011(11 Calif0111 ill Tnfiitnte of Tccllllology Past(IlIJI Jhps( wOlken al Htud~ing the COTlHlitlllllts of the acetone extract and other conlltituellis of guuyule
30 TECHNICAL BULLETIN 920 U S DEPT OF AGRICULTURE
tillation of similar resinous exudate in the writers laborntory has yielded approximately 4 percent of the whole as the telmiddotpene oir fracshytion Haagen-Smit and his eoorktrs nportec1 thttt about 25 percent of the acetone extract from guayule branches is parthenyl cinnamate and 6 percent of the bark (ltortpamp-phlotm) extraet is parthenyl cinshynamate These workers fm-thcI reported that 25 lwletnt of the nc(shytone extract frolll bLllllches is a compound with the tlI1pilicaL formula CBoH400a 1 percent is a compound llwltillg at 2P to 2T5deg C and 1 percent of the extract from the ]eav(s is tl (olllpoulld nwlting at 100
to 1710 1Valtei (6) reported that 3 to -l perc(nt of the tI(eton( txtract
of leaves and flowering StPIllS of guayulc eonsists of waxlike substances soluble in olgallic soln~nts but insoluble in at(l and (on(ent1llted H 2S04 The flactions mentioned on the basis of (onHLTutle esti shymates of amoullts actually isolated tlecoullted for about H ptIcent of the totalncetollt~ so]ubles extracttd from tll( guuYllle 11 rub The other constituents ltlilaill to be i(](ntifi(d
RUBBER AND RESINS CALIBHATION CVHES
Typical culibndioll Clllves iol Iuhbpl and I(sins bas(d 011 (ldtLminttshytions made nccoLdillg to the plocCdmC outlin(d 011 pages middotb to 1G arc shown in figulPS 5 and 1+ The spCdlopliotoll1lttL en (OIOIjlllctCI readings are plottCd on s(lIlilogalitllllliC pappi ag-ail1st (Il 11IbblI (011shy
100 ~ 90
80 ~ 70 ~
z 1amp1 0 II 1amp1 IL
1amp1 0 Z
60
50
40 ~ltI 30 ~ en z ~ ltI II ~ 20 C) ~ oJ
10 o 2 3 4 5 6 7 8 9 10
RU8BER IN 25-ML VOLUME (MG)
bull
bull
bull FI(lURE 14--Ctlihration curve fotmiddot gllftYlIlc lubb01 (Hct(lings Oil COIPIIHlII tlOl1hl(
monochromator SlCClrophotolllet(r with 7fiO-11IL Illtel alld Hllp Wll ( IHlll()
bull
bull
bull
RAPID PHOTOMETRIC DETE~MINATION OF RUBBER AND RESINS 3]
centrations From a casual inspection of these CUlTes it would appeltr that Beers law does not hold Actual tests indicitted that Beers law was applicable only within a narrow range in the upper portion of the curves The analyticlil results on the basis of photornetric readings nre therefore calculated by direct reference to calibration curves or from reference tables of equivalent values bllscd on the cnlibllltion curves
Calibration curves for kok-saghyz alld heyea lI11tulltl rubbers and Buna S (GR-S Chem Gum IV Goodyear) and butyl (GR-I Standshyard Oil Co Protoc) sYJlthetic rubbers are hOWllil1 figure 15 The samples of kok-saghyz rubber were furnished by the Diyision of Rubshy
100
90 ~I) ()
z 0
1amp1 a
~ a
80
70
60
s 1amp1 ~ ~ 0 ~ KOj-SAGHYZ 0 l Il
50
HEVEA~ ~
40
100
90
~ 0 80z Q 70a Co)
a 60 ~ 0 0 x 50Il
40 ~----~~----~------~------~------~--~ o 2 3 4 5
RUBBER IN 25-ML VOLUME(MG)
FmUIlE 15-CaJiblation curves fOl kok-snghyz h(YCII Bunn S lind butyl rubb~ls (Readings on gy((yn photoelectric colorimeter with i20-lIIp filtpl and 6-ml aperture)
32 TECHNICAl BUIJLETIN [)20) 1 S DEP1 OF AGrnCUIlfURE
Iwt Plant JIl(I~t ignlioll of thi BlII(un and (1( l))(parcd according to 11( SPltI1((-Culd (]] (6) PIO(((lllll Hlpt pal( CLPPe was (xtmch(L with acetone blI()Ieit W 1I(gt(11l a ttnlldal(l
SEXSlllVllY Ol~ llETJIonS
By lip pIO((l(II11P olltlillP(l 011 ]Hlg( +n Iowa (lOOl IIIg (11 1111i(l0shygmm (gHlllllla) of 1hblI ill a 2)1111 yoltll1ll (all )(gt dltpltld Oil tltl Col(man (lohlP mOIlWhlOl1lHlOl l-I)((t 101 l1lOt 0111 ci( I ill1ilnlly 001 mg of Iublwr ill a 2J-1ll1 n]ulllP Illay bl Ilad Oil till EnI)1I photoshyllectlie (O]oLillllt(I Thll ya lllll- 011 tilt IHl-i- (J I (xl ad iOI1 fmlll 02 gill of til-lI tH(JI(lillg to tllP -lllndal(l jll()(pdull 1(PIPStlIt IlO()2J tlnd 002) P(IT(lIt of llIbl1ll IPI)(((inly bull1t1lollgh -lI1t low allils can be d((d(middot(1 il lIoullt1 Ill IPtllizpd thnt till PIIOl ill PlI(Plltng( or tll( al110unt dltlIllIilll(J i ltlatlpl high ill tili PIY lo Itlllgl 111 aetllllllladie(middot Ill( lopl lillliL 111)(1(1 lIw (ollllil ions of tlil ]lI()(lltlIIIl u ol1tlinpd ipt at l11 11I1 or 1111gt11(1 illt i-1ll1 Ollllll IlPIPltPlltillg 01 p(gtl(pnt of JllUiJtL un tlll 1Hli or (xlla ion rlOI11 II rlll of tisSIll
EIlIlOH COSIIlIHIIO
In Oldpl to H(IIp ill )1lHtPltt pl((iioll illlpIi1I- it i lH((SSHI to slnlldHIdiz(i rigidly 111( Pl()((dlll( 0 illdi(ntpd Oil pnglt- - to J( If lids i dOlH tlip lXIHlinwnlal PIIll is t(middotdllld 10 n ndninlllill
Illlt pl(iioll of (hI ]lIPPllt 1IHllwd Oil til basi of ]llllP llIllJt1 alld Ipsinssollltions call hI jlldgl(J 110111 figllll Hi lileh lio- til HPIlIgl d(intioll oft -illgIP lI1lnSIlIlIIIlnt in lHi((lltagl of Ill( alllOllllt 01 Illhshy1)() 01 lpsins d((PI1I1 iJlld TIl( (1101 PlI(Plltaglt H1( gi (1 101 OJ) to
RUBBER IN 25-ML VOLUMEMG) 004 01 02 03 04
i= I I IZCtOW
fbA ICtU CtCt WW a
01 02 03 04 05 06 07 08 09 100 = RUBBER (PERCENT)
RUBBER IN 25-ML VOLUME (MG) 10 20 30
~ I CtZ
bBOw Ctu CtCt Ww o I~
010 50 100 150 200 250 RUBBER (PERCENT)
RESINS IN 25-ML VOLUME(MG) 10__ __3-0_ 40 50 60 70 60 90 100--_-- 2_-0
Ct~ -r- 1 I OZ
WCt UCt b C wCtW
a o I I 150 250
RESINS (PERCENT) o 10 50 100 200
bllI 1tI W-Yllnl dtd1 ioll I I 11l1 11IlI11 1(111(11 1 III Plll- IlIIIlol1 01 IIim~
bull
bull
bull solution Il basis J o golH of tiSSII (JlILCl-nt (11(11) for (~I) (l)1 til O 1I1
of luhllpl lin 1 III I (I Ill of lUhlJPl nllll laquo I J to 111 nlg of IlSlllgt (Itllillgs on ]iYllyu pllolwh-llrk CO[IJlilll(-(PI with nOHIP Iiltlr lIntl U-lIll allcrture)
RAPID PHOTOlJElRIC DELEHlllNAllON Cn HUBBER AND H1~SINS 33
10 mg of rubber anel1 to 10 mg of resins in a gJ-m1 yolumC For
bull
bull
bull
comparative ptuposes the leslllts arc also calculated on the basis oJvershycentage rubber OL tltsills in 02 gllI of tissul As WOlllL be expcet(d the error increases sOIlHgthlf for 1(lali nmiddotly low COlHell t1llf iOlls oj rllbbeL or resins The curves in figure 1(j s1l0 that ill til(gt Illlge Ol to 10 pCrshyeent of lubber the elTOI rangts Jroll1 abollt Ll to II) ]IlC(lIt abo(~ this mlllc tIlt (ITOl d(((ts(s to (ollsidlItbly ltmiddotss (han 1 1lICPllt of tlH mllollnt ltl((Lmill(d Hil1lilally in tlH (lISl of l(sins analysis (fig 10) the ltLTor is (onsit1eIubly INS than 1 PlLllnt ill (he lallgp of 11 t~) ~() penPII t
In nil ([lSl of lllhblI alld (sins lx(Inltpd tIOIl1 (issups Ol addcltl to tisslle lxtlads (s(( tabhmiddots (i H) illyolillg ll01P o(lllntiolls the eLI01
is hig]wl thun that indilHtld in figllll ((j Im pUIl Ill )])p I tllllllsins solutlOII
COlllUCIIOXFOH IXSOLl-IlLl~ Ilgsqgt(Jg
111 th( Jllo(pdulP ollllillPd 011 paw I till illsolllhll isSII Ipidll( tflpl (xttlw(ioll is (Ptill tlw lIask l(lll till xtlct i l1wdp up to yoltlllH It is not rOllPllipnt (0 IPt()PI qWlIltitati(Ir III(lw[olH a 11(1 pllooll extlnlfs of guuyull I is-lll alll thl1l main t11l111 up (0 YOIUllllmiddot bpCaUHI sllch all additiollal stltp wottld]) tillll-C(JllS11ll1illg Th( Iogiea nll(gtIshynntin is to mnkp tltl lXtlUCt Llld Ipsidup lip to OllillH in till original flask andi llPSStllY 10 llwlno tl OIIpdioll wlHIl (allIlnting [hc llshy
Hults f(JI [hl oll111lC displupd hy till ins()lllbh llsidll( III it l)picat (IXpednHllt (ollsisting of Jhp lppJiea(iolls if was Iollnd llftt at ~iiO ( 02 gill 01 Iuhhll pillS IPill-fl(( lisslI(gt (lollpdll fot llwistUlC ou basis of dlyillp ut lOW 101 ) llOlll-j (lbp(ld only t~ llllUll voiul11P of OOk7D~- OO(lOO(i Ill of lllthyl bolnl(yl 1lIOll( (lplhlli(al-t(Tnltle sp gl () Ii I ll(Hli (j at ~)) -gtitllP tl1(gt 1It101111( () r t is-lIl xt Iadld j sl1lall til( PlIOI dul to Ill(gt insoll1blp Ip~idll is slllall III [0111 ill( wOtk it (all lJp diIpgal(ll(l
]hcon~lIY OF HllIllgl AiO HESIS AIH)gl) TO EXTlIACI OP
GlYlLE TISSlg
Tnl)ll G L(IHpslntillp (ypi(nl llld(~ SllOS (hat all a plngl of HIOK PlI((nt ot lltl pltl( Ilhl)(l acldpd to tllP Itll h iolJut1 InmiddottcJllP xhnet
of guayulp tiSI1( WllS 1l((PllIl Tlli nllintioll flOlll (olllplpU I((OYshy
PIY i within flll pxp(IiIlHuttllIIOI ~illli]llly fnbll Ii llows thn 1111 llYlIUgl of 1O(1~ ])(I(Pllt of gllllYllII 1(-i1l- add(d to II( (pllosol( (xshytrae of IUllY]l t i~HI Is 1l(oPIPI
THl~ (~ Hf (Off Ill of 1111)( J OJ I~il~ lItfI(( In ~(JI1IJk~ Ilf (111 [lI1Il fI2 lIII
0 tlUfllllit i~~I1
Instrument
---- ----~---- bull shy 1(1
Colemun ruono~ltrOUlllt()r 2t) II sJl~ctroJlhOL()lIIeter with 2tJ I iflllllI wnclength Fetting 21 II nntl 0-1111 WU HI hUJl(L _ L U
Ill 7Evolyn photo~lcclrie (olor JU [ imctcr with iO-llIl filler IV (I
H1 0 t I I
llImiddot lUn WII 1011 HIO Wn mil lUulon
10 JIg1111 IUI ml lUl anh Io aLn 111)_I ) III li lU It 2) deg wn2SU DD
Irl JIll II IIr II US II
1110(1 lULa lUI IlK) IJ WU
I( llI Htl tNI 1(111 2tlNI HI 0 221) lllil t2S 0 1~ 10 1~13
In (I 2117 I
10U 1l(J ~ 4 _H_j ___
9middotJIlJ5 10115 10 00 lUU5 flUU 4li (tl03 9(11)
leIlKl 1l~)5 lOOU l1KIr JOIS un 003 OIl Ii
34 lECHNlCAL BULLErIN 920 U S DEPT OF AGRICULlURE
COMPARISON OF PHOTOMETRIC A1D MODJIoIED SPENCE-CALDWfLL METHODS OF RUBBER ANALYSIS
Guayule samples were analyzed by the photQ111etIic method and by bull the modified Spenc(gt-Cnldwell mcthod The values in table 7 represhyselltativ(I of typical results indieate It -atisfactory dcglpe of conformshyjty between the two methods in thl range of tiSSlHH with llHHC than OJ) percent of rubbtImiddot On the bnsis of the amounts determimd the results in this runge for the plmiddotts(nt lIlcthod ayernge apploxinHltely j percent highcr
~LAIII~ 7-(oIllJl(i~on of lltlllrIic (IIri mOtllinl SJl(II(r-(ulri-wall IIIrtlwrl~ of rlrrlIIillillfl 11)1)(1 COIIrll of UI(III
1 Flowers frllm amiddotmonth-oltl nursery plants
YAIIIATJO- OF SIli(LE DETEnt1NATIONS Fnoll TnEIIllIEAN
Rllbbel (Uall8i8-Thc plcCision of thc pLcsent method when gunyule tissues Hr( nnnlyz((1 for rubber may be j udg(d flom I Ill datil presentcd in table H TIl(se dahl -how that thl pplCPlltag( uriation of single determinatiom from nwan yullles with low standllrd enolS ranges from less than 1 to 4 p(gtrlent
R(8in~ wWlsi-r-s lndi(a((1 011 page ~j he INntlts s((uled hy the present phoolllttric nsins llHt hod are not tliltly (olllpalable with those of the grtLVimetri( ncetol1l-cxtlt1(tioll II1etho(l Thjs made it necesSllry to selc(t another lalibllltion staudud-tlll Ipsinous exullate from gullyule shrub-thut gies relatively COllstlllt photometric readshyings (table 5) The resin (olltents of guayule roots branchcs or leavcs usually ran(~e from about) to 1-1middot pelcellt The ple(ision of the present methotf WhCll gUHyule thslllS lIe analyzed for reins may be judged from the datalHmiddotpscllted ill table 9 1h(se data show that the p(lcelltage variatiun of sillgle lhmiddott(Lminntions iLO11 meun ynlnes with low standard NTOrs rangcs from about 05 to 4 percent
bull
bull
bull
bull
bull
RAPID PHOTOMETHIC DElEruIINAlION OJ RUBBEH AND HESINS 35
IAIILE 8-luriation inclieute rubller (mallSM of [1wIIle tissue bll thc 1111O0Illclc metwII
Vnrlntlon~Ilbher I (rom mean
ierCtnl Percelll ~OU -22 ~ 25 +27 ~ 20 +18 ~UO -22---------1_______ 51110 0G6 bullbullbullbullbullbull _bullbull
10 ro ----=ii41075 -01 1000 +11 1010 +13
rlln HI itil 1l9~ 1_ ___ =-~~~
115511 ~ US -111 III II 1575 -13 115 b tiS -I a 111 h WlU +22IIM-(middot bull 11K -1Ja Illi c 1000 +03 1J5H1 W +l)7 ll1imiddot tl 1575 -13
Mcnn 15951 131
1102-11 21fJ() +21l102-h _ ~~)SO -17 1102-c bullbull 21CO +21n02middotd ~OIiO -26
2 r~plusmn Il~ 21151 261 I -~-------bull---__ _~~_~______l-___--_
1 lhe$ 1111($ I1n (or SlIlIIllltS Stpnnltplr PHrilClld IIrtlrdlng 10 1hr prollIlIlr( OIiIIiIl(o(I on Imgt$ 4 to IC ~tcond nUlI1 hlr r(J)[ltnts stl1ndnnl llrrot of tilt 1I1(1111
1_1l1~ n-J(lri(iot in relli(Upound rpoundsins (lllalIsfs of VIOJII( lixsue b1 the lhomillric lII(lloli
-- ---~--- - __-------- shybull I I I I Varlgttton
_________~___ ~~lu_n_Jl_Q_~~~_____ ______I__~_o~S_J frOID lDean
Percent Percentgt458-1 ~65 +41IWtl-li 130 -a2Hli8c aliO +26S41i8-d bull 130 -32
1(-011 34I10Olifgt __ bullbull __ ~--====
li-9~2n 881) -06 li-9~2-b Si5 o ~HH2middot(middot S i5 -6$-H2middotd 000 +1
8851 054
O i5 +6 9 i5 +6 950 -20 U75 +6
H-liG3o-n bull -1 n-li6~b bull __ _ -IH-IWH +4H-l61511 bull -1
1tmiddottlU
62~-lI __ 62~-b ij24-( bull OH-Ji
(-Ull
I rll(St oluls nre tor separately ~xlrflCled SllllllllCS IlctOrdlug lO procedure outllned ou pages 4 to 10 i Secoud number r~prtgeulS stulldMd error of lIe menn
36 TECHNICAL BULLETIN 920 t ~ DEPT OF A(]RICCLTCRE
ReUUER A~ALYSrS I~ CRCOE-RcuUER PROOCCTS
Sew rapid photometric m(lthod~fol the ddellllinttion of rubber and reii Hi ill uaYllp ti--ut htp lllell pIPHnl pd oil pag( ~l to In A brief H1111111tlY of It similar rnpid llHthod fm 1I1hb~rllnltlysis of u1lulcanizNl tlIldp lubbll pl(Hlmtlt whielt i~ bn-(tldo on the prill o
ciples dehtilcd tlllLe follows Duplltate nt-gm sllmph of the finely cliyiliNl IlInttlitiup wlirllll out [~ei-()l (all hl lIf((tinmiddotjv INd to lt1iyidl till alllpl) TIll kltolll-olubll portion of till )111(11( tlrc di-olved a- indh-Htpd fot thmiddot lllnkill~ of -tlllHlunlluhhll olutiou Oil Pt 1II hut tIl IUlIp Hn lIn l-fplImiddotd 10 lHI-ml rolllllltti( fln-k antil1ltld(lup to Olllll1l The bnlulUp or till JllO(ldllll i- thatutlilllll on paWs -1- 1 IHI Ii 111( 1(111 1- nIP IXPIP--pd nil til IHi or Iw oligiJla w(lullt of I Ill (I11l1p-I1l11Ilt1 1)(0(11(1
Hupitl PlllimiPJojgtiWllllllllh llIltllOd~ fOJ Ihl llPtlmiddotminntion of ImiddotUlJbll tlnd 1(-illo- ill -111111 Illllph of gutlYllll tiUl IIll dl-eli)ed 111() IlltlY d~o Ill nltlI1lld fOl III Iwl Illhlwl- and l~iJlmiddotb(lLiJlg plant TIllt l[Olllhup hns nlo b(l1l ntuptpl fot IIH lltlIll1illtltioll of lllhbpl ill 11lHhrublwl Pl(Jdlld~ HIIl 1111 hI ndaptld JoJ IIll ann lysis of ynt1J(gt( ic lllbbl[- The llllthmb HIP 1gtn(11 fill tIll fol1owill plimiph- III Grinding
tIll PIOPlly driPl t i~lIl 01 Ul tillg tIll pnHhHt to tll l((lllilllllh~lel of filWlH-- til plllllit qIHlIllilnth( lXIIHtioll 01 IIlbhlI 01 1(--IJl- () llsing oXWllutld olnuh (kttoJls IIt(talp and() fllltil for LIbbel and IH(ltIlIlyptIJllIllIoolYlnJld-o flJllh 101 niJlsl with t(lathelr high IlPililig points 111 to n C) l]olle or in mixt tIll thllt Pll mit tlll rnphllxututioll of luhll(l OJ [middot(ill ill ~() to (l mi1lutp It r(latiwly high 1lllIllllltlltP Ill to 1~11 ) l) lllllipitntillu till luhblI OL Imiddot(ill frolll aliquot () f till oltn ion I IlIlllI-i () f Hlltabhmiddot pl(~(i]litallt (willifhmiddotd lthmwl fOl IIlhlHI Hild llitlifild lllr fOJ JP-illl t~) IIlHkillphotollllliilPIIIIiIlof PlllPlltal of liht tLaIlS mittUl(P lIftlI IlIlbll (II Il in PIlipitalioll 11 II WI( Iplllh thnt (limiJlall till PIIOl dill 10 xtralllOlh (0101 (till dptl1minntinll Iph jill 011 tIll dtwlopllIlJIl of H HIli rOI1ll tlllbidity 111 hpl than I (olot rI
jJlIlpOP-ofallnlyi-I ( p(lllil1thb IIllijOI1ll turbidity or 1llt[lIinmiddotd d(ltl of jgtIp(ii(JlI l)~ lIltlkillU tIl plllltollllmiddottri( ntdillU al tandinu tiJlH~ (dlllilll wlli(h IhlllH(lill-- IP 1llutinmiddotly tnhll) t1ll1t an hlsl~1 oil the (oJlItlIlllItion of IIlhlHI Ill I(ill (lIPIipitat((L
TIll -I(p ill till jll()(Plhul HIP 1-- follOylt (1) 1l~UIIL uJ1lplls of thwl UJfJlllHl (II tliddl(l HUt dlipd 11Illtplial an lXIllltel with11 Ill of till nlnll ill t (oU tlllltIPlll[gtPImiddotatlup oil Iath at 11 Cbull fol 11 minutl I) iIP1lIin(middot(lohd til( (XUtllhllll Jltldl lip to It middotml ynlmlll til( (nlifild by (Illlifllgiuu HlId thlPl IlI nliql1ot of tIl (IalioPlllxUlltl nll Uillltlmiddotll(t to l-llll OIlIIlIllril fiuk- (1) For a trial Ilnditlg 0111 III tlll j liJmiddot~t IllHII IIjI to Ohlllll with lilt Pll shy(ilitnnl a 1(11 it 111 (Dod fill llli lIut ( ptotoJIIltlil IPtlllillg-- of pllllntnl or liuht tlUtllIlillal(I oil n (lpel OphotnJlllllI at rase hng-tlt (If 11 llJ Ill Ol It lollllil1lPtImiddott lloyidld with tIll P10]11 I 1110110shy
Ihlolllltt hmiddot Ii1llI Olllhi lIatioll for -1IpItillg UJlproXilll1l tply Wtl P ]Plwth )0 mp are HHlltk TIll Illldillg lliJtaillld fol tIlt 4-milutl tliall(~ll-
bull
bull
bull
RAPID PHOTO~IETRIC DETERIINATIOX OF R(BBER AXD RESINS 37
ing are referred to a table of equhmiddottllut~ previously p1(pa1elt1 on the
bull basis of 4-minute reac1inJ~ for tilE nmge of lot1telltlatiol1- of rubber or resins to bE elHOlll1t(led tmd gidn thtmiddot -tnnlillfr tillIP fill rUbbEt or resins aiter prE(ipitlltiol1 lwfolE photoIllNliI j(tltlill1 un IUade The r(middotnmining dllplllatt aliquot lll then HHllil up te ol1l1Jle and lpoundadillg ale marle ut the -tandillfr tiUlE iudklltll ill rhl tall1lmiddot for the final r(adillg~ -1) 111( milli1lnm or p(tCPlltllt- of lllhbpL (II 1(-in pr(s(nt are rpadholU a prlpan(l table of lquiltlput for tlll photoshymetric readings h1~l(l ill pnell e1-E on pxpPlilmlItal lhln 1111(1 u-ing as stimtlltlds pure luhbll in 1l1bbtl milllYb aIHI guaYllh ll-ill- lxIHlatt~ in resins detNIl1111lttion I
LlTERATlRE CLTED
(1) lUnSbull 1fl36 THE mURMIXTIOS IIF IOTA RE I III OOl THER llT~II
F1 bullrol IlY U(T1l0fll UfSlfi ~rrnrl r flm lt1 KEYS TI Bill Chern 114 44J-l59 illns
t1 ~ICPHHlObullbull T 1J3bull~ lUTHOO roa THE PtRInCAnu Or a(lIUl IRrIlHU It of TIn
PLRIHEU Htllllflt [ i Bill lallllall 111 Rmiddot 711middotj iIlus
I ) RHBERG P B Ul5 A METHIlO Or ~u(ronrll-nl Hi tIII rUIl[1 f71 ii illlI
bull 14 Hoss W flbull and HARDESTY J O
llH IR1ltDII Of HfITilIZfmiddotR DllIJS ltt 1 Yl fll Off gI bern JIIIlI i ~middotmiddotlf IIl
101 SPEltCE D nnd CuoWELr ~I L 1933 DETER~n-ATIOo OF RtBBER Ii nrllllpoundRBfR Iusr 1uI II1 amI
Em~ifl cttIliIa~~ r Ell i 71middot7i l11 (HI WALTER E D
1U44 ISO~nlS OF PRTlltSrr 1trHpoundV bull l UI n W lHHt (Tnmiddot 1ETS FROM GiYI l~iIl lItr Clttrn SII J UI titJ middotn9--C1 ilIu
17 J YOEbullbullr H lO~( roLORIlETRT 771 IPmiddot nl -W Yurk f H Plrwptric hmica
naly-II rimttry lUll XphHHlnmiddot~ y 1 1
11
HI) ~ fPHELolzTRf 57 111bull Lin xw Yk t H lt PhmeHt CblUlmiddot ila AnaiY~l~-(H lithrry and XIhmiddotILpfIY Y wirh enomiddot rrJlllrjr hy H KtlJnJU11 I
t~1I --- and ~ARVER L 1f41 nlua-w ~in L liLhr IS IP ll~ XIW Yrk
bull For-sale by th~ ~a~fr1nt~nf1ent Dt~c~~ogtnts-~ s t1i rArnn~ut Pn~~~ tJffieshy
Washington 5 D C bull Pl lU ~nts
-----
26 rECHNICAL BULLEfiN 920 U S DEPl OF AGRICULlUHE
100
90
80(I) C)
z Ci 70 UI a 0 60 a ~ UI ~ 500 ~ 0 I Il 40
30
A 20
0
100
90
(I) 80 C)
z Ci 70 UI a 0
60a ~ UI E 0 50 ~ 0 I Il
4-0
30
B 20
0
--
--shy ---shy---
2 4 6 6 10 12 14 16
---shy= ~ ~ shy
-
2
025 05
10
15
20
25 -30
35 40
SO
-60
=70 80
16 20 2224 26 26 30
OS
- 10
IS
20
2S
30
35 40
-50
-60 -70 -80
bull MGPE 25-ML
VOLUME
bull
MGPER 25-ML VOLUME
Florm 12-EtTld (If till1l or Slllldill~ 011 light transmittallce (01 (A) gUllyulc lnUIl(I plccipitllitd frOIll llltt h~l isobutyl Ielollt solution Ily neidilic(l ethanul bull null (B) gUllyule ll~illii pre(ipitated flom aeltoll~lllcetOlll-Cl])osolY( 3-7 solushy11011 by H(illilip(i l1U (HPlldillg~ nt -lIlillult Ifllpluls 011 Evelyn photoelectric colorimellr with jU-lllp tlllll alit U-1I11 npN(lle spp also table 2)
bull
bull
RAPID PI-IOlOMEllUC DElEnMINAlION OF RUBBER AND RESINS 27
TADIbullbull ] 4-ReZation of amiddotmount of middottbber pleeipitate(Z Oln metltlIL isobutyl ketone 80lutions by OS-pereent H 2SO in 95-pere(lIIt ethanol to umollnt of resin8 udde(l U8 indivute(Z by colorimetrio readinU8
(Rubber ami resins cnlculntcd on bnsis of amounts in 5middotml ullquuts of extract from 02 gm of tissue in a 2fllll olumo( bull
Hubucl r~cocrell whcll rcsins nddcd as IndIcated Htbbor al1dcd (pllcollt) ---shy
__________bull_________ ~_12rpcrc~15011crccllt 7511crccnt IOOpcrcent
PerCtllt ercellt Percellt Percellt Percent o o o o o) 50 250 263 252 25000 500 500 500 500 700 750 750 751 749
1200 1250 1250 1250 1250
EXTRACTION TEMPEHATURE AND TIME
Typical experiments to detllmine the time required to secure maxishymum extmction of rubber und ltsills at 115deg U Ilre sUlIlmarized in figule 13 the solvents used-methyl isobutyl ketone for rubber anrl Ilcetonylacetone-cellosolve 3-7 for resins extraction-are very eflicicnt since under the conditions indicttted maximum values were secured after 30 minutes of ext1llction The most eflicient liquid for the bath (lig 1) used in extrtlcting rubber or resins is ~ high-grade cylinder oil (S A E ~O) The sand bath and such liquids as glycerol have proved unsatisfactory
RUBBER AND RESINS STANDARDS
According to the National BULeau of Standards 1-_ lhclc Is no gellcrnlly recoglllz(d standard lIIutcrlul [ior II rubber standard] The rubber hydroCllrbon ill llifferent samples of conmlcrciul smoked sheet or pale crepe from heclI pluntlltions nries from l~ 10 04 llercent of the totul nutletmiddot the most 11Ioruble conditions Of preparation
McPherson () has described a procedure for the pLeparation of pure heve~ (Hevea brasiliensis (H B K) MueH Arg) rubber from crude rubber or latex In the absence howevcr of ~ generally recogshyn12ed stalldard for rubber hydlQcllrbon [caoutchouc (CnHUs) xJ the standard adopted was that of the relnthely pure product secured from gunyule tissue txtractiotl nccording to the Spence-CaldweU method (5) or the motlified PIOCCdUlU of Hohnes lind Haasis (p 2) The details for constructing the calibration CULes are given on page 10 Standard rubber samples apparenl-]y can be stored for a long timc under the conditions des(libed on page 10 The duplicate colorimetric lendings for glULyule rubber newly extracted by the modified SpenceshyCaldwell method were ()J2 ench as compared with US) each for the sample extracted by the same method but stored 1 years In each case colorimeter rcadinllS were made on mixtures containing 2 mg of rubber in It 25-1111 Yolume
The selection of tt suitable standurd for guayule resins presents some dilliculties Tll(~ acetone extract of gUllyult estimated on (l gravishymetric busis~ for instance proved to be variable depending on the type of tissue sampled or season of sumpling because such fractions as
COllllllunlcntion dul(lt1 Octohtr 22 11H3
28 QECHNICAL BULLEQIN 920 U S DEPT OF AGRICTTIIlURE
16~==========================115 shy
14 bulli= 13 z ~ 12
ffi II Q
10 c w 9a w
8gto () 7w a
6a w
5en III ) 4 a
3
2
A 00 5 10 20 30 60 90
14~------------------------------------------- bull13
i= 12 z w II ()
a 10 w Q
9 c w 8 a w 7gt o () 6 w a 5 If)
z 4 If)
w 3 a
2
o+B~~__~__~____________~__________~ 5 10 20 30 60 90
HEATING TIME (111 NUTES)
lllGUltE 13-lDffect of time o( lICntillg O2-gm samples of gunynle tissue with solYlIt nt llfio C on lo(OVl)ry of lllhlJer alld 1Isim Lt HlIhblL extracted with methyl isohntyllwtone B resins Cxtll1cted with aCftonyla(etonc-cellosolve 3-7 bull
chlorophyll are weighed along with the resins in the acetone extruct but are not estimated by the present photometric method (fig 0) 1he use of a diffeJent stanclttrd waS therefore indicated
bull
bull
bull
RAPID PHOTOMETRIC DETERMINATION OF HUBBIm AND HESINS 29
The resins standard selected is based on n relatively pure source of resins the rcsinous exudnte 011 the stems of guuyule plants IJldimishynary expeliments with the resi nouS cxuclate from diffcrellt gllayu Ie strains of various ages indicatc nHlt there is little YaLiation in this subshystance on the basis of Colorimct(r readings 011 2-mg aliqllots of 01shypercent solution in It 2i-ml volume (tabl( li) Expelilll(lnts have shown that the air-dried (xuclate contains 3RtOH p(Ic(nt of -volatile matter This material is l(latiyt~ly stablp ill (OlllpoBition and is npshypurpntly on ly slight ly hygroBcopic as shoWIl ill Ia bl(1 1 Tlrp Ipsinolls exudate may be jJleplpd in two wayi-i fl liSP as a stallClHld-(l) the clpan exudate is clripd iol Ghouls at ()1deg C at W indlPs of a(lIum Hnd aftclbCinOglOund ill a molfalis 1)I(spI((I intn airtight COllilinel OL
(2) tllP Cx7lclate is clissolllt1 ill a(lhllll and filtplpd PlactieaJlyall of the acetm1l is thpn lYapolntwl olt OPI a stlam or atCt hath and Ow residue is dripd ground an(( PI(sPIld as ill tllp fin lllethocl Tlwse two prepalHtlolls a1( (ompalpd in ta hlp ) 111( (((tails fOl ~t()lil1g the resins standald and (onstlllcting the calibration CUITPS alc given Oil page ]2
lAIIIg fi-CUIIIllrsoi (lJ lIr-dr(1I IIIIi 1((11 II II-()I-tr((l l(sil~ 11111111(8 of I II 1111Ie
[Colorimetric rrndill~s 011 1~I11 phulll(Iclrie eolorillJct[lr with i~()middotmll (100- to iiOIIIIl) fillcr [lnd 5-1111 lIperture preeipitantl part ofO5middotPIrctllt 10 to 5 paris of IIOj
nupliclllc(oloritwt([
nIl(lin~s (hIlSlcAg~ ofSlmillXo JrNliltlCllt of fPsiJI$ L1Xtlrlntp on 2 IIIg ofplanls fllsins (XIHIIlt~Jwr 25-1111 vol
tII1(1) 1
leflTs Various _ bull ____ bullbullbullbull 3-9 Colll)Josiltrlairmiddotltlricfl bullbullbull nf)2 002
])0____ bullbullbull _bull __ _ bullbull ~-l Composilld (ri d at n5 C in aUmiddotimh lWUUllJ for l (jOuj(ja hours])0______ bullbullbull __ bull ___ bull 3-0 COJIlpositld disso]NI in neptolll f1l1erNl fl(lf()ll( GGO i(jO (Ivaporntld olT OV(1r Stpl1l11 halh TesidlH drl(ld I1t fi5deg ( ill anmiddotinch VIl(Unlll for 0 houlS bull
middot106 __ bullbull _ Jir~c1rild_~_~_ _~_ ~_~ _ ~ ____ _ __ _ OUu GOifina_~ ~ _ ~~_~ ___ _ _fln~ ~~ ~ ___ ~ __ 6(imiddotI tiliA H)[_ ltlu bullbull i18 tisSflOabullbullbullbull__ bullbullbullbullbullbullbullbull lt10bullbullbull _ tillO llitO406__ bullbull __ bullbull __ bull __ __ lt10_ Utl2 fon591_ fo__ bull liGa oOa 406bullbull _ __ lt10bullbullbull_ li5S OM
j Ph( vnluls in Uw Inst COIUIIlIl indieatp thnt gunyulp fesinous (IIHlnt( wlwtlwr dfircl hi Yn(tlLJ1l1 wilh L~ perc(nt loss of volntllt wutl pr or tWl c1rild giVPd npproxil1lnh1ly t Iw snllw colorinwtCr rNHiing- 011 till busis of aliquot~ cOlllniuiug 2 IJI~ of flsillS lXIHlntp l)tIf 25-mI volultl( Ihil- illdicate~ thl11 Uw UITW IJ1flS~ of olnshytile mntl(f prt~(iJlitnt(d gins npproxilllntlly Uw $1II1l (oiOfirnl1tlf ftudiTlJs ns tho ftsidtw A pnlill1jllaf~middot (XIlltrinllnt indicutls thlli th VUllltill muller l(lIlSists of thl Ilrplne oil fmcl ion I5-(1Il gtnplls or rlsitlOtlS (lxudntll gnvll by stPll1U distillation nn Uefllgl of 011111 of jl(lfPlIW oil with npproximHte tilllsity (If OHIi lind lhus rrprlsll1ll( IlPIJroximllt(I~ 01 Jerccllt Of t he original weight 1hls lllrClnlage complrcs wllh 38 llltrC(ntlost by drvinI( in IICllnllJ
aSplusmnUH perceilt or orlginlll weightlosl
The wailnble illfolJllntioll on tlH (ow-JitlPllts of the gunYllle r(~shyillOllS exudate alld tl1( HeetOlIP ext act of gaylp ti~slw is sllIllmarized in this paragraph lYalttI (u) alld also Hangcn-Slllit lind his coworkshyers 16 reported that 20 percent of the resinolls exudate from gUltyulc stems is parthenyl cinnamaie (CHuOH=CHC020 11JI2r) Steam disshy
15 (OIlIJIIIIUicatioll flom A T Haai(II~l11it llId (0011(11 Calif0111 ill Tnfiitnte of Tccllllology Past(IlIJI Jhps( wOlken al Htud~ing the COTlHlitlllllts of the acetone extract and other conlltituellis of guuyule
30 TECHNICAL BULLETIN 920 U S DEPT OF AGRICULTURE
tillation of similar resinous exudate in the writers laborntory has yielded approximately 4 percent of the whole as the telmiddotpene oir fracshytion Haagen-Smit and his eoorktrs nportec1 thttt about 25 percent of the acetone extract from guayule branches is parthenyl cinnamate and 6 percent of the bark (ltortpamp-phlotm) extraet is parthenyl cinshynamate These workers fm-thcI reported that 25 lwletnt of the nc(shytone extract frolll bLllllches is a compound with the tlI1pilicaL formula CBoH400a 1 percent is a compound llwltillg at 2P to 2T5deg C and 1 percent of the extract from the ]eav(s is tl (olllpoulld nwlting at 100
to 1710 1Valtei (6) reported that 3 to -l perc(nt of the tI(eton( txtract
of leaves and flowering StPIllS of guayulc eonsists of waxlike substances soluble in olgallic soln~nts but insoluble in at(l and (on(ent1llted H 2S04 The flactions mentioned on the basis of (onHLTutle esti shymates of amoullts actually isolated tlecoullted for about H ptIcent of the totalncetollt~ so]ubles extracttd from tll( guuYllle 11 rub The other constituents ltlilaill to be i(](ntifi(d
RUBBER AND RESINS CALIBHATION CVHES
Typical culibndioll Clllves iol Iuhbpl and I(sins bas(d 011 (ldtLminttshytions made nccoLdillg to the plocCdmC outlin(d 011 pages middotb to 1G arc shown in figulPS 5 and 1+ The spCdlopliotoll1lttL en (OIOIjlllctCI readings are plottCd on s(lIlilogalitllllliC pappi ag-ail1st (Il 11IbblI (011shy
100 ~ 90
80 ~ 70 ~
z 1amp1 0 II 1amp1 IL
1amp1 0 Z
60
50
40 ~ltI 30 ~ en z ~ ltI II ~ 20 C) ~ oJ
10 o 2 3 4 5 6 7 8 9 10
RU8BER IN 25-ML VOLUME (MG)
bull
bull
bull FI(lURE 14--Ctlihration curve fotmiddot gllftYlIlc lubb01 (Hct(lings Oil COIPIIHlII tlOl1hl(
monochromator SlCClrophotolllet(r with 7fiO-11IL Illtel alld Hllp Wll ( IHlll()
bull
bull
bull
RAPID PHOTOMETRIC DETE~MINATION OF RUBBER AND RESINS 3]
centrations From a casual inspection of these CUlTes it would appeltr that Beers law does not hold Actual tests indicitted that Beers law was applicable only within a narrow range in the upper portion of the curves The analyticlil results on the basis of photornetric readings nre therefore calculated by direct reference to calibration curves or from reference tables of equivalent values bllscd on the cnlibllltion curves
Calibration curves for kok-saghyz alld heyea lI11tulltl rubbers and Buna S (GR-S Chem Gum IV Goodyear) and butyl (GR-I Standshyard Oil Co Protoc) sYJlthetic rubbers are hOWllil1 figure 15 The samples of kok-saghyz rubber were furnished by the Diyision of Rubshy
100
90 ~I) ()
z 0
1amp1 a
~ a
80
70
60
s 1amp1 ~ ~ 0 ~ KOj-SAGHYZ 0 l Il
50
HEVEA~ ~
40
100
90
~ 0 80z Q 70a Co)
a 60 ~ 0 0 x 50Il
40 ~----~~----~------~------~------~--~ o 2 3 4 5
RUBBER IN 25-ML VOLUME(MG)
FmUIlE 15-CaJiblation curves fOl kok-snghyz h(YCII Bunn S lind butyl rubb~ls (Readings on gy((yn photoelectric colorimeter with i20-lIIp filtpl and 6-ml aperture)
32 TECHNICAl BUIJLETIN [)20) 1 S DEP1 OF AGrnCUIlfURE
Iwt Plant JIl(I~t ignlioll of thi BlII(un and (1( l))(parcd according to 11( SPltI1((-Culd (]] (6) PIO(((lllll Hlpt pal( CLPPe was (xtmch(L with acetone blI()Ieit W 1I(gt(11l a ttnlldal(l
SEXSlllVllY Ol~ llETJIonS
By lip pIO((l(II11P olltlillP(l 011 ]Hlg( +n Iowa (lOOl IIIg (11 1111i(l0shygmm (gHlllllla) of 1hblI ill a 2)1111 yoltll1ll (all )(gt dltpltld Oil tltl Col(man (lohlP mOIlWhlOl1lHlOl l-I)((t 101 l1lOt 0111 ci( I ill1ilnlly 001 mg of Iublwr ill a 2J-1ll1 n]ulllP Illay bl Ilad Oil till EnI)1I photoshyllectlie (O]oLillllt(I Thll ya lllll- 011 tilt IHl-i- (J I (xl ad iOI1 fmlll 02 gill of til-lI tH(JI(lillg to tllP -lllndal(l jll()(pdull 1(PIPStlIt IlO()2J tlnd 002) P(IT(lIt of llIbl1ll IPI)(((inly bull1t1lollgh -lI1t low allils can be d((d(middot(1 il lIoullt1 Ill IPtllizpd thnt till PIIOl ill PlI(Plltng( or tll( al110unt dltlIllIilll(J i ltlatlpl high ill tili PIY lo Itlllgl 111 aetllllllladie(middot Ill( lopl lillliL 111)(1(1 lIw (ollllil ions of tlil ]lI()(lltlIIIl u ol1tlinpd ipt at l11 11I1 or 1111gt11(1 illt i-1ll1 Ollllll IlPIPltPlltillg 01 p(gtl(pnt of JllUiJtL un tlll 1Hli or (xlla ion rlOI11 II rlll of tisSIll
EIlIlOH COSIIlIHIIO
In Oldpl to H(IIp ill )1lHtPltt pl((iioll illlpIi1I- it i lH((SSHI to slnlldHIdiz(i rigidly 111( Pl()((dlll( 0 illdi(ntpd Oil pnglt- - to J( If lids i dOlH tlip lXIHlinwnlal PIIll is t(middotdllld 10 n ndninlllill
Illlt pl(iioll of (hI ]lIPPllt 1IHllwd Oil til basi of ]llllP llIllJt1 alld Ipsinssollltions call hI jlldgl(J 110111 figllll Hi lileh lio- til HPIlIgl d(intioll oft -illgIP lI1lnSIlIlIIIlnt in lHi((lltagl of Ill( alllOllllt 01 Illhshy1)() 01 lpsins d((PI1I1 iJlld TIl( (1101 PlI(Plltaglt H1( gi (1 101 OJ) to
RUBBER IN 25-ML VOLUMEMG) 004 01 02 03 04
i= I I IZCtOW
fbA ICtU CtCt WW a
01 02 03 04 05 06 07 08 09 100 = RUBBER (PERCENT)
RUBBER IN 25-ML VOLUME (MG) 10 20 30
~ I CtZ
bBOw Ctu CtCt Ww o I~
010 50 100 150 200 250 RUBBER (PERCENT)
RESINS IN 25-ML VOLUME(MG) 10__ __3-0_ 40 50 60 70 60 90 100--_-- 2_-0
Ct~ -r- 1 I OZ
WCt UCt b C wCtW
a o I I 150 250
RESINS (PERCENT) o 10 50 100 200
bllI 1tI W-Yllnl dtd1 ioll I I 11l1 11IlI11 1(111(11 1 III Plll- IlIIIlol1 01 IIim~
bull
bull
bull solution Il basis J o golH of tiSSII (JlILCl-nt (11(11) for (~I) (l)1 til O 1I1
of luhllpl lin 1 III I (I Ill of lUhlJPl nllll laquo I J to 111 nlg of IlSlllgt (Itllillgs on ]iYllyu pllolwh-llrk CO[IJlilll(-(PI with nOHIP Iiltlr lIntl U-lIll allcrture)
RAPID PHOTOlJElRIC DELEHlllNAllON Cn HUBBER AND H1~SINS 33
10 mg of rubber anel1 to 10 mg of resins in a gJ-m1 yolumC For
bull
bull
bull
comparative ptuposes the leslllts arc also calculated on the basis oJvershycentage rubber OL tltsills in 02 gllI of tissul As WOlllL be expcet(d the error increases sOIlHgthlf for 1(lali nmiddotly low COlHell t1llf iOlls oj rllbbeL or resins The curves in figure 1(j s1l0 that ill til(gt Illlge Ol to 10 pCrshyeent of lubber the elTOI rangts Jroll1 abollt Ll to II) ]IlC(lIt abo(~ this mlllc tIlt (ITOl d(((ts(s to (ollsidlItbly ltmiddotss (han 1 1lICPllt of tlH mllollnt ltl((Lmill(d Hil1lilally in tlH (lISl of l(sins analysis (fig 10) the ltLTor is (onsit1eIubly INS than 1 PlLllnt ill (he lallgp of 11 t~) ~() penPII t
In nil ([lSl of lllhblI alld (sins lx(Inltpd tIOIl1 (issups Ol addcltl to tisslle lxtlads (s(( tabhmiddots (i H) illyolillg ll01P o(lllntiolls the eLI01
is hig]wl thun that indilHtld in figllll ((j Im pUIl Ill )])p I tllllllsins solutlOII
COlllUCIIOXFOH IXSOLl-IlLl~ Ilgsqgt(Jg
111 th( Jllo(pdulP ollllillPd 011 paw I till illsolllhll isSII Ipidll( tflpl (xttlw(ioll is (Ptill tlw lIask l(lll till xtlct i l1wdp up to yoltlllH It is not rOllPllipnt (0 IPt()PI qWlIltitati(Ir III(lw[olH a 11(1 pllooll extlnlfs of guuyull I is-lll alll thl1l main t11l111 up (0 YOIUllllmiddot bpCaUHI sllch all additiollal stltp wottld]) tillll-C(JllS11ll1illg Th( Iogiea nll(gtIshynntin is to mnkp tltl lXtlUCt Llld Ipsidup lip to OllillH in till original flask andi llPSStllY 10 llwlno tl OIIpdioll wlHIl (allIlnting [hc llshy
Hults f(JI [hl oll111lC displupd hy till ins()lllbh llsidll( III it l)picat (IXpednHllt (ollsisting of Jhp lppJiea(iolls if was Iollnd llftt at ~iiO ( 02 gill 01 Iuhhll pillS IPill-fl(( lisslI(gt (lollpdll fot llwistUlC ou basis of dlyillp ut lOW 101 ) llOlll-j (lbp(ld only t~ llllUll voiul11P of OOk7D~- OO(lOO(i Ill of lllthyl bolnl(yl 1lIOll( (lplhlli(al-t(Tnltle sp gl () Ii I ll(Hli (j at ~)) -gtitllP tl1(gt 1It101111( () r t is-lIl xt Iadld j sl1lall til( PlIOI dul to Ill(gt insoll1blp Ip~idll is slllall III [0111 ill( wOtk it (all lJp diIpgal(ll(l
]hcon~lIY OF HllIllgl AiO HESIS AIH)gl) TO EXTlIACI OP
GlYlLE TISSlg
Tnl)ll G L(IHpslntillp (ypi(nl llld(~ SllOS (hat all a plngl of HIOK PlI((nt ot lltl pltl( Ilhl)(l acldpd to tllP Itll h iolJut1 InmiddottcJllP xhnet
of guayulp tiSI1( WllS 1l((PllIl Tlli nllintioll flOlll (olllplpU I((OYshy
PIY i within flll pxp(IiIlHuttllIIOI ~illli]llly fnbll Ii llows thn 1111 llYlIUgl of 1O(1~ ])(I(Pllt of gllllYllII 1(-i1l- add(d to II( (pllosol( (xshytrae of IUllY]l t i~HI Is 1l(oPIPI
THl~ (~ Hf (Off Ill of 1111)( J OJ I~il~ lItfI(( In ~(JI1IJk~ Ilf (111 [lI1Il fI2 lIII
0 tlUfllllit i~~I1
Instrument
---- ----~---- bull shy 1(1
Colemun ruono~ltrOUlllt()r 2t) II sJl~ctroJlhOL()lIIeter with 2tJ I iflllllI wnclength Fetting 21 II nntl 0-1111 WU HI hUJl(L _ L U
Ill 7Evolyn photo~lcclrie (olor JU [ imctcr with iO-llIl filler IV (I
H1 0 t I I
llImiddot lUn WII 1011 HIO Wn mil lUulon
10 JIg1111 IUI ml lUl anh Io aLn 111)_I ) III li lU It 2) deg wn2SU DD
Irl JIll II IIr II US II
1110(1 lULa lUI IlK) IJ WU
I( llI Htl tNI 1(111 2tlNI HI 0 221) lllil t2S 0 1~ 10 1~13
In (I 2117 I
10U 1l(J ~ 4 _H_j ___
9middotJIlJ5 10115 10 00 lUU5 flUU 4li (tl03 9(11)
leIlKl 1l~)5 lOOU l1KIr JOIS un 003 OIl Ii
34 lECHNlCAL BULLErIN 920 U S DEPT OF AGRICULlURE
COMPARISON OF PHOTOMETRIC A1D MODJIoIED SPENCE-CALDWfLL METHODS OF RUBBER ANALYSIS
Guayule samples were analyzed by the photQ111etIic method and by bull the modified Spenc(gt-Cnldwell mcthod The values in table 7 represhyselltativ(I of typical results indieate It -atisfactory dcglpe of conformshyjty between the two methods in thl range of tiSSlHH with llHHC than OJ) percent of rubbtImiddot On the bnsis of the amounts determimd the results in this runge for the plmiddotts(nt lIlcthod ayernge apploxinHltely j percent highcr
~LAIII~ 7-(oIllJl(i~on of lltlllrIic (IIri mOtllinl SJl(II(r-(ulri-wall IIIrtlwrl~ of rlrrlIIillillfl 11)1)(1 COIIrll of UI(III
1 Flowers frllm amiddotmonth-oltl nursery plants
YAIIIATJO- OF SIli(LE DETEnt1NATIONS Fnoll TnEIIllIEAN
Rllbbel (Uall8i8-Thc plcCision of thc pLcsent method when gunyule tissues Hr( nnnlyz((1 for rubber may be j udg(d flom I Ill datil presentcd in table H TIl(se dahl -how that thl pplCPlltag( uriation of single determinatiom from nwan yullles with low standllrd enolS ranges from less than 1 to 4 p(gtrlent
R(8in~ wWlsi-r-s lndi(a((1 011 page ~j he INntlts s((uled hy the present phoolllttric nsins llHt hod are not tliltly (olllpalable with those of the grtLVimetri( ncetol1l-cxtlt1(tioll II1etho(l Thjs made it necesSllry to selc(t another lalibllltion staudud-tlll Ipsinous exullate from gullyule shrub-thut gies relatively COllstlllt photometric readshyings (table 5) The resin (olltents of guayule roots branchcs or leavcs usually ran(~e from about) to 1-1middot pelcellt The ple(ision of the present methotf WhCll gUHyule thslllS lIe analyzed for reins may be judged from the datalHmiddotpscllted ill table 9 1h(se data show that the p(lcelltage variatiun of sillgle lhmiddott(Lminntions iLO11 meun ynlnes with low standard NTOrs rangcs from about 05 to 4 percent
bull
bull
bull
bull
bull
RAPID PHOTOMETHIC DElEruIINAlION OJ RUBBEH AND HESINS 35
IAIILE 8-luriation inclieute rubller (mallSM of [1wIIle tissue bll thc 1111O0Illclc metwII
Vnrlntlon~Ilbher I (rom mean
ierCtnl Percelll ~OU -22 ~ 25 +27 ~ 20 +18 ~UO -22---------1_______ 51110 0G6 bullbullbullbullbullbull _bullbull
10 ro ----=ii41075 -01 1000 +11 1010 +13
rlln HI itil 1l9~ 1_ ___ =-~~~
115511 ~ US -111 III II 1575 -13 115 b tiS -I a 111 h WlU +22IIM-(middot bull 11K -1Ja Illi c 1000 +03 1J5H1 W +l)7 ll1imiddot tl 1575 -13
Mcnn 15951 131
1102-11 21fJ() +21l102-h _ ~~)SO -17 1102-c bullbull 21CO +21n02middotd ~OIiO -26
2 r~plusmn Il~ 21151 261 I -~-------bull---__ _~~_~______l-___--_
1 lhe$ 1111($ I1n (or SlIlIIllltS Stpnnltplr PHrilClld IIrtlrdlng 10 1hr prollIlIlr( OIiIIiIl(o(I on Imgt$ 4 to IC ~tcond nUlI1 hlr r(J)[ltnts stl1ndnnl llrrot of tilt 1I1(1111
1_1l1~ n-J(lri(iot in relli(Upound rpoundsins (lllalIsfs of VIOJII( lixsue b1 the lhomillric lII(lloli
-- ---~--- - __-------- shybull I I I I Varlgttton
_________~___ ~~lu_n_Jl_Q_~~~_____ ______I__~_o~S_J frOID lDean
Percent Percentgt458-1 ~65 +41IWtl-li 130 -a2Hli8c aliO +26S41i8-d bull 130 -32
1(-011 34I10Olifgt __ bullbull __ ~--====
li-9~2n 881) -06 li-9~2-b Si5 o ~HH2middot(middot S i5 -6$-H2middotd 000 +1
8851 054
O i5 +6 9 i5 +6 950 -20 U75 +6
H-liG3o-n bull -1 n-li6~b bull __ _ -IH-IWH +4H-l61511 bull -1
1tmiddottlU
62~-lI __ 62~-b ij24-( bull OH-Ji
(-Ull
I rll(St oluls nre tor separately ~xlrflCled SllllllllCS IlctOrdlug lO procedure outllned ou pages 4 to 10 i Secoud number r~prtgeulS stulldMd error of lIe menn
36 TECHNICAL BULLETIN 920 t ~ DEPT OF A(]RICCLTCRE
ReUUER A~ALYSrS I~ CRCOE-RcuUER PROOCCTS
Sew rapid photometric m(lthod~fol the ddellllinttion of rubber and reii Hi ill uaYllp ti--ut htp lllell pIPHnl pd oil pag( ~l to In A brief H1111111tlY of It similar rnpid llHthod fm 1I1hb~rllnltlysis of u1lulcanizNl tlIldp lubbll pl(Hlmtlt whielt i~ bn-(tldo on the prill o
ciples dehtilcd tlllLe follows Duplltate nt-gm sllmph of the finely cliyiliNl IlInttlitiup wlirllll out [~ei-()l (all hl lIf((tinmiddotjv INd to lt1iyidl till alllpl) TIll kltolll-olubll portion of till )111(11( tlrc di-olved a- indh-Htpd fot thmiddot lllnkill~ of -tlllHlunlluhhll olutiou Oil Pt 1II hut tIl IUlIp Hn lIn l-fplImiddotd 10 lHI-ml rolllllltti( fln-k antil1ltld(lup to Olllll1l The bnlulUp or till JllO(ldllll i- thatutlilllll on paWs -1- 1 IHI Ii 111( 1(111 1- nIP IXPIP--pd nil til IHi or Iw oligiJla w(lullt of I Ill (I11l1p-I1l11Ilt1 1)(0(11(1
Hupitl PlllimiPJojgtiWllllllllh llIltllOd~ fOJ Ihl llPtlmiddotminntion of ImiddotUlJbll tlnd 1(-illo- ill -111111 Illllph of gutlYllll tiUl IIll dl-eli)ed 111() IlltlY d~o Ill nltlI1lld fOl III Iwl Illhlwl- and l~iJlmiddotb(lLiJlg plant TIllt l[Olllhup hns nlo b(l1l ntuptpl fot IIH lltlIll1illtltioll of lllhbpl ill 11lHhrublwl Pl(Jdlld~ HIIl 1111 hI ndaptld JoJ IIll ann lysis of ynt1J(gt( ic lllbbl[- The llllthmb HIP 1gtn(11 fill tIll fol1owill plimiph- III Grinding
tIll PIOPlly driPl t i~lIl 01 Ul tillg tIll pnHhHt to tll l((lllilllllh~lel of filWlH-- til plllllit qIHlIllilnth( lXIIHtioll 01 IIlbhlI 01 1(--IJl- () llsing oXWllutld olnuh (kttoJls IIt(talp and() fllltil for LIbbel and IH(ltIlIlyptIJllIllIoolYlnJld-o flJllh 101 niJlsl with t(lathelr high IlPililig points 111 to n C) l]olle or in mixt tIll thllt Pll mit tlll rnphllxututioll of luhll(l OJ [middot(ill ill ~() to (l mi1lutp It r(latiwly high 1lllIllllltlltP Ill to 1~11 ) l) lllllipitntillu till luhblI OL Imiddot(ill frolll aliquot () f till oltn ion I IlIlllI-i () f Hlltabhmiddot pl(~(i]litallt (willifhmiddotd lthmwl fOl IIlhlHI Hild llitlifild lllr fOJ JP-illl t~) IIlHkillphotollllliilPIIIIiIlof PlllPlltal of liht tLaIlS mittUl(P lIftlI IlIlbll (II Il in PIlipitalioll 11 II WI( Iplllh thnt (limiJlall till PIIOl dill 10 xtralllOlh (0101 (till dptl1minntinll Iph jill 011 tIll dtwlopllIlJIl of H HIli rOI1ll tlllbidity 111 hpl than I (olot rI
jJlIlpOP-ofallnlyi-I ( p(lllil1thb IIllijOI1ll turbidity or 1llt[lIinmiddotd d(ltl of jgtIp(ii(JlI l)~ lIltlkillU tIl plllltollllmiddottri( ntdillU al tandinu tiJlH~ (dlllilll wlli(h IhlllH(lill-- IP 1llutinmiddotly tnhll) t1ll1t an hlsl~1 oil the (oJlItlIlllItion of IIlhlHI Ill I(ill (lIPIipitat((L
TIll -I(p ill till jll()(Plhul HIP 1-- follOylt (1) 1l~UIIL uJ1lplls of thwl UJfJlllHl (II tliddl(l HUt dlipd 11Illtplial an lXIllltel with11 Ill of till nlnll ill t (oU tlllltIPlll[gtPImiddotatlup oil Iath at 11 Cbull fol 11 minutl I) iIP1lIin(middot(lohd til( (XUtllhllll Jltldl lip to It middotml ynlmlll til( (nlifild by (Illlifllgiuu HlId thlPl IlI nliql1ot of tIl (IalioPlllxUlltl nll Uillltlmiddotll(t to l-llll OIlIIlIllril fiuk- (1) For a trial Ilnditlg 0111 III tlll j liJmiddot~t IllHII IIjI to Ohlllll with lilt Pll shy(ilitnnl a 1(11 it 111 (Dod fill llli lIut ( ptotoJIIltlil IPtlllillg-- of pllllntnl or liuht tlUtllIlillal(I oil n (lpel OphotnJlllllI at rase hng-tlt (If 11 llJ Ill Ol It lollllil1lPtImiddott lloyidld with tIll P10]11 I 1110110shy
Ihlolllltt hmiddot Ii1llI Olllhi lIatioll for -1IpItillg UJlproXilll1l tply Wtl P ]Plwth )0 mp are HHlltk TIll Illldillg lliJtaillld fol tIlt 4-milutl tliall(~ll-
bull
bull
bull
RAPID PHOTO~IETRIC DETERIINATIOX OF R(BBER AXD RESINS 37
ing are referred to a table of equhmiddottllut~ previously p1(pa1elt1 on the
bull basis of 4-minute reac1inJ~ for tilE nmge of lot1telltlatiol1- of rubber or resins to bE elHOlll1t(led tmd gidn thtmiddot -tnnlillfr tillIP fill rUbbEt or resins aiter prE(ipitlltiol1 lwfolE photoIllNliI j(tltlill1 un IUade The r(middotnmining dllplllatt aliquot lll then HHllil up te ol1l1Jle and lpoundadillg ale marle ut the -tandillfr tiUlE iudklltll ill rhl tall1lmiddot for the final r(adillg~ -1) 111( milli1lnm or p(tCPlltllt- of lllhbpL (II 1(-in pr(s(nt are rpadholU a prlpan(l table of lquiltlput for tlll photoshymetric readings h1~l(l ill pnell e1-E on pxpPlilmlItal lhln 1111(1 u-ing as stimtlltlds pure luhbll in 1l1bbtl milllYb aIHI guaYllh ll-ill- lxIHlatt~ in resins detNIl1111lttion I
LlTERATlRE CLTED
(1) lUnSbull 1fl36 THE mURMIXTIOS IIF IOTA RE I III OOl THER llT~II
F1 bullrol IlY U(T1l0fll UfSlfi ~rrnrl r flm lt1 KEYS TI Bill Chern 114 44J-l59 illns
t1 ~ICPHHlObullbull T 1J3bull~ lUTHOO roa THE PtRInCAnu Or a(lIUl IRrIlHU It of TIn
PLRIHEU Htllllflt [ i Bill lallllall 111 Rmiddot 711middotj iIlus
I ) RHBERG P B Ul5 A METHIlO Or ~u(ronrll-nl Hi tIII rUIl[1 f71 ii illlI
bull 14 Hoss W flbull and HARDESTY J O
llH IR1ltDII Of HfITilIZfmiddotR DllIJS ltt 1 Yl fll Off gI bern JIIIlI i ~middotmiddotlf IIl
101 SPEltCE D nnd CuoWELr ~I L 1933 DETER~n-ATIOo OF RtBBER Ii nrllllpoundRBfR Iusr 1uI II1 amI
Em~ifl cttIliIa~~ r Ell i 71middot7i l11 (HI WALTER E D
1U44 ISO~nlS OF PRTlltSrr 1trHpoundV bull l UI n W lHHt (Tnmiddot 1ETS FROM GiYI l~iIl lItr Clttrn SII J UI titJ middotn9--C1 ilIu
17 J YOEbullbullr H lO~( roLORIlETRT 771 IPmiddot nl -W Yurk f H Plrwptric hmica
naly-II rimttry lUll XphHHlnmiddot~ y 1 1
11
HI) ~ fPHELolzTRf 57 111bull Lin xw Yk t H lt PhmeHt CblUlmiddot ila AnaiY~l~-(H lithrry and XIhmiddotILpfIY Y wirh enomiddot rrJlllrjr hy H KtlJnJU11 I
t~1I --- and ~ARVER L 1f41 nlua-w ~in L liLhr IS IP ll~ XIW Yrk
bull For-sale by th~ ~a~fr1nt~nf1ent Dt~c~~ogtnts-~ s t1i rArnn~ut Pn~~~ tJffieshy
Washington 5 D C bull Pl lU ~nts
bull
bull
RAPID PI-IOlOMEllUC DElEnMINAlION OF RUBBER AND RESINS 27
TADIbullbull ] 4-ReZation of amiddotmount of middottbber pleeipitate(Z Oln metltlIL isobutyl ketone 80lutions by OS-pereent H 2SO in 95-pere(lIIt ethanol to umollnt of resin8 udde(l U8 indivute(Z by colorimetrio readinU8
(Rubber ami resins cnlculntcd on bnsis of amounts in 5middotml ullquuts of extract from 02 gm of tissue in a 2fllll olumo( bull
Hubucl r~cocrell whcll rcsins nddcd as IndIcated Htbbor al1dcd (pllcollt) ---shy
__________bull_________ ~_12rpcrc~15011crccllt 7511crccnt IOOpcrcent
PerCtllt ercellt Percellt Percellt Percent o o o o o) 50 250 263 252 25000 500 500 500 500 700 750 750 751 749
1200 1250 1250 1250 1250
EXTRACTION TEMPEHATURE AND TIME
Typical experiments to detllmine the time required to secure maxishymum extmction of rubber und ltsills at 115deg U Ilre sUlIlmarized in figule 13 the solvents used-methyl isobutyl ketone for rubber anrl Ilcetonylacetone-cellosolve 3-7 for resins extraction-are very eflicicnt since under the conditions indicttted maximum values were secured after 30 minutes of ext1llction The most eflicient liquid for the bath (lig 1) used in extrtlcting rubber or resins is ~ high-grade cylinder oil (S A E ~O) The sand bath and such liquids as glycerol have proved unsatisfactory
RUBBER AND RESINS STANDARDS
According to the National BULeau of Standards 1-_ lhclc Is no gellcrnlly recoglllz(d standard lIIutcrlul [ior II rubber standard] The rubber hydroCllrbon ill llifferent samples of conmlcrciul smoked sheet or pale crepe from heclI pluntlltions nries from l~ 10 04 llercent of the totul nutletmiddot the most 11Ioruble conditions Of preparation
McPherson () has described a procedure for the pLeparation of pure heve~ (Hevea brasiliensis (H B K) MueH Arg) rubber from crude rubber or latex In the absence howevcr of ~ generally recogshyn12ed stalldard for rubber hydlQcllrbon [caoutchouc (CnHUs) xJ the standard adopted was that of the relnthely pure product secured from gunyule tissue txtractiotl nccording to the Spence-CaldweU method (5) or the motlified PIOCCdUlU of Hohnes lind Haasis (p 2) The details for constructing the calibration CULes are given on page 10 Standard rubber samples apparenl-]y can be stored for a long timc under the conditions des(libed on page 10 The duplicate colorimetric lendings for glULyule rubber newly extracted by the modified SpenceshyCaldwell method were ()J2 ench as compared with US) each for the sample extracted by the same method but stored 1 years In each case colorimeter rcadinllS were made on mixtures containing 2 mg of rubber in It 25-1111 Yolume
The selection of tt suitable standurd for guayule resins presents some dilliculties Tll(~ acetone extract of gUllyult estimated on (l gravishymetric busis~ for instance proved to be variable depending on the type of tissue sampled or season of sumpling because such fractions as
COllllllunlcntion dul(lt1 Octohtr 22 11H3
28 QECHNICAL BULLEQIN 920 U S DEPT OF AGRICTTIIlURE
16~==========================115 shy
14 bulli= 13 z ~ 12
ffi II Q
10 c w 9a w
8gto () 7w a
6a w
5en III ) 4 a
3
2
A 00 5 10 20 30 60 90
14~------------------------------------------- bull13
i= 12 z w II ()
a 10 w Q
9 c w 8 a w 7gt o () 6 w a 5 If)
z 4 If)
w 3 a
2
o+B~~__~__~____________~__________~ 5 10 20 30 60 90
HEATING TIME (111 NUTES)
lllGUltE 13-lDffect of time o( lICntillg O2-gm samples of gunynle tissue with solYlIt nt llfio C on lo(OVl)ry of lllhlJer alld 1Isim Lt HlIhblL extracted with methyl isohntyllwtone B resins Cxtll1cted with aCftonyla(etonc-cellosolve 3-7 bull
chlorophyll are weighed along with the resins in the acetone extruct but are not estimated by the present photometric method (fig 0) 1he use of a diffeJent stanclttrd waS therefore indicated
bull
bull
bull
RAPID PHOTOMETRIC DETERMINATION OF HUBBIm AND HESINS 29
The resins standard selected is based on n relatively pure source of resins the rcsinous exudnte 011 the stems of guuyule plants IJldimishynary expeliments with the resi nouS cxuclate from diffcrellt gllayu Ie strains of various ages indicatc nHlt there is little YaLiation in this subshystance on the basis of Colorimct(r readings 011 2-mg aliqllots of 01shypercent solution in It 2i-ml volume (tabl( li) Expelilll(lnts have shown that the air-dried (xuclate contains 3RtOH p(Ic(nt of -volatile matter This material is l(latiyt~ly stablp ill (OlllpoBition and is npshypurpntly on ly slight ly hygroBcopic as shoWIl ill Ia bl(1 1 Tlrp Ipsinolls exudate may be jJleplpd in two wayi-i fl liSP as a stallClHld-(l) the clpan exudate is clripd iol Ghouls at ()1deg C at W indlPs of a(lIum Hnd aftclbCinOglOund ill a molfalis 1)I(spI((I intn airtight COllilinel OL
(2) tllP Cx7lclate is clissolllt1 ill a(lhllll and filtplpd PlactieaJlyall of the acetm1l is thpn lYapolntwl olt OPI a stlam or atCt hath and Ow residue is dripd ground an(( PI(sPIld as ill tllp fin lllethocl Tlwse two prepalHtlolls a1( (ompalpd in ta hlp ) 111( (((tails fOl ~t()lil1g the resins standald and (onstlllcting the calibration CUITPS alc given Oil page ]2
lAIIIg fi-CUIIIllrsoi (lJ lIr-dr(1I IIIIi 1((11 II II-()I-tr((l l(sil~ 11111111(8 of I II 1111Ie
[Colorimetric rrndill~s 011 1~I11 phulll(Iclrie eolorillJct[lr with i~()middotmll (100- to iiOIIIIl) fillcr [lnd 5-1111 lIperture preeipitantl part ofO5middotPIrctllt 10 to 5 paris of IIOj
nupliclllc(oloritwt([
nIl(lin~s (hIlSlcAg~ ofSlmillXo JrNliltlCllt of fPsiJI$ L1Xtlrlntp on 2 IIIg ofplanls fllsins (XIHIIlt~Jwr 25-1111 vol
tII1(1) 1
leflTs Various _ bull ____ bullbullbullbull 3-9 Colll)Josiltrlairmiddotltlricfl bullbullbull nf)2 002
])0____ bullbullbull _bull __ _ bullbull ~-l Composilld (ri d at n5 C in aUmiddotimh lWUUllJ for l (jOuj(ja hours])0______ bullbullbull __ bull ___ bull 3-0 COJIlpositld disso]NI in neptolll f1l1erNl fl(lf()ll( GGO i(jO (Ivaporntld olT OV(1r Stpl1l11 halh TesidlH drl(ld I1t fi5deg ( ill anmiddotinch VIl(Unlll for 0 houlS bull
middot106 __ bullbull _ Jir~c1rild_~_~_ _~_ ~_~ _ ~ ____ _ __ _ OUu GOifina_~ ~ _ ~~_~ ___ _ _fln~ ~~ ~ ___ ~ __ 6(imiddotI tiliA H)[_ ltlu bullbull i18 tisSflOabullbullbullbull__ bullbullbullbullbullbullbullbull lt10bullbullbull _ tillO llitO406__ bullbull __ bullbull __ bull __ __ lt10_ Utl2 fon591_ fo__ bull liGa oOa 406bullbull _ __ lt10bullbullbull_ li5S OM
j Ph( vnluls in Uw Inst COIUIIlIl indieatp thnt gunyulp fesinous (IIHlnt( wlwtlwr dfircl hi Yn(tlLJ1l1 wilh L~ perc(nt loss of volntllt wutl pr or tWl c1rild giVPd npproxil1lnh1ly t Iw snllw colorinwtCr rNHiing- 011 till busis of aliquot~ cOlllniuiug 2 IJI~ of flsillS lXIHlntp l)tIf 25-mI volultl( Ihil- illdicate~ thl11 Uw UITW IJ1flS~ of olnshytile mntl(f prt~(iJlitnt(d gins npproxilllntlly Uw $1II1l (oiOfirnl1tlf ftudiTlJs ns tho ftsidtw A pnlill1jllaf~middot (XIlltrinllnt indicutls thlli th VUllltill muller l(lIlSists of thl Ilrplne oil fmcl ion I5-(1Il gtnplls or rlsitlOtlS (lxudntll gnvll by stPll1U distillation nn Uefllgl of 011111 of jl(lfPlIW oil with npproximHte tilllsity (If OHIi lind lhus rrprlsll1ll( IlPIJroximllt(I~ 01 Jerccllt Of t he original weight 1hls lllrClnlage complrcs wllh 38 llltrC(ntlost by drvinI( in IICllnllJ
aSplusmnUH perceilt or orlginlll weightlosl
The wailnble illfolJllntioll on tlH (ow-JitlPllts of the gunYllle r(~shyillOllS exudate alld tl1( HeetOlIP ext act of gaylp ti~slw is sllIllmarized in this paragraph lYalttI (u) alld also Hangcn-Slllit lind his coworkshyers 16 reported that 20 percent of the resinolls exudate from gUltyulc stems is parthenyl cinnamaie (CHuOH=CHC020 11JI2r) Steam disshy
15 (OIlIJIIIIUicatioll flom A T Haai(II~l11it llId (0011(11 Calif0111 ill Tnfiitnte of Tccllllology Past(IlIJI Jhps( wOlken al Htud~ing the COTlHlitlllllts of the acetone extract and other conlltituellis of guuyule
30 TECHNICAL BULLETIN 920 U S DEPT OF AGRICULTURE
tillation of similar resinous exudate in the writers laborntory has yielded approximately 4 percent of the whole as the telmiddotpene oir fracshytion Haagen-Smit and his eoorktrs nportec1 thttt about 25 percent of the acetone extract from guayule branches is parthenyl cinnamate and 6 percent of the bark (ltortpamp-phlotm) extraet is parthenyl cinshynamate These workers fm-thcI reported that 25 lwletnt of the nc(shytone extract frolll bLllllches is a compound with the tlI1pilicaL formula CBoH400a 1 percent is a compound llwltillg at 2P to 2T5deg C and 1 percent of the extract from the ]eav(s is tl (olllpoulld nwlting at 100
to 1710 1Valtei (6) reported that 3 to -l perc(nt of the tI(eton( txtract
of leaves and flowering StPIllS of guayulc eonsists of waxlike substances soluble in olgallic soln~nts but insoluble in at(l and (on(ent1llted H 2S04 The flactions mentioned on the basis of (onHLTutle esti shymates of amoullts actually isolated tlecoullted for about H ptIcent of the totalncetollt~ so]ubles extracttd from tll( guuYllle 11 rub The other constituents ltlilaill to be i(](ntifi(d
RUBBER AND RESINS CALIBHATION CVHES
Typical culibndioll Clllves iol Iuhbpl and I(sins bas(d 011 (ldtLminttshytions made nccoLdillg to the plocCdmC outlin(d 011 pages middotb to 1G arc shown in figulPS 5 and 1+ The spCdlopliotoll1lttL en (OIOIjlllctCI readings are plottCd on s(lIlilogalitllllliC pappi ag-ail1st (Il 11IbblI (011shy
100 ~ 90
80 ~ 70 ~
z 1amp1 0 II 1amp1 IL
1amp1 0 Z
60
50
40 ~ltI 30 ~ en z ~ ltI II ~ 20 C) ~ oJ
10 o 2 3 4 5 6 7 8 9 10
RU8BER IN 25-ML VOLUME (MG)
bull
bull
bull FI(lURE 14--Ctlihration curve fotmiddot gllftYlIlc lubb01 (Hct(lings Oil COIPIIHlII tlOl1hl(
monochromator SlCClrophotolllet(r with 7fiO-11IL Illtel alld Hllp Wll ( IHlll()
bull
bull
bull
RAPID PHOTOMETRIC DETE~MINATION OF RUBBER AND RESINS 3]
centrations From a casual inspection of these CUlTes it would appeltr that Beers law does not hold Actual tests indicitted that Beers law was applicable only within a narrow range in the upper portion of the curves The analyticlil results on the basis of photornetric readings nre therefore calculated by direct reference to calibration curves or from reference tables of equivalent values bllscd on the cnlibllltion curves
Calibration curves for kok-saghyz alld heyea lI11tulltl rubbers and Buna S (GR-S Chem Gum IV Goodyear) and butyl (GR-I Standshyard Oil Co Protoc) sYJlthetic rubbers are hOWllil1 figure 15 The samples of kok-saghyz rubber were furnished by the Diyision of Rubshy
100
90 ~I) ()
z 0
1amp1 a
~ a
80
70
60
s 1amp1 ~ ~ 0 ~ KOj-SAGHYZ 0 l Il
50
HEVEA~ ~
40
100
90
~ 0 80z Q 70a Co)
a 60 ~ 0 0 x 50Il
40 ~----~~----~------~------~------~--~ o 2 3 4 5
RUBBER IN 25-ML VOLUME(MG)
FmUIlE 15-CaJiblation curves fOl kok-snghyz h(YCII Bunn S lind butyl rubb~ls (Readings on gy((yn photoelectric colorimeter with i20-lIIp filtpl and 6-ml aperture)
32 TECHNICAl BUIJLETIN [)20) 1 S DEP1 OF AGrnCUIlfURE
Iwt Plant JIl(I~t ignlioll of thi BlII(un and (1( l))(parcd according to 11( SPltI1((-Culd (]] (6) PIO(((lllll Hlpt pal( CLPPe was (xtmch(L with acetone blI()Ieit W 1I(gt(11l a ttnlldal(l
SEXSlllVllY Ol~ llETJIonS
By lip pIO((l(II11P olltlillP(l 011 ]Hlg( +n Iowa (lOOl IIIg (11 1111i(l0shygmm (gHlllllla) of 1hblI ill a 2)1111 yoltll1ll (all )(gt dltpltld Oil tltl Col(man (lohlP mOIlWhlOl1lHlOl l-I)((t 101 l1lOt 0111 ci( I ill1ilnlly 001 mg of Iublwr ill a 2J-1ll1 n]ulllP Illay bl Ilad Oil till EnI)1I photoshyllectlie (O]oLillllt(I Thll ya lllll- 011 tilt IHl-i- (J I (xl ad iOI1 fmlll 02 gill of til-lI tH(JI(lillg to tllP -lllndal(l jll()(pdull 1(PIPStlIt IlO()2J tlnd 002) P(IT(lIt of llIbl1ll IPI)(((inly bull1t1lollgh -lI1t low allils can be d((d(middot(1 il lIoullt1 Ill IPtllizpd thnt till PIIOl ill PlI(Plltng( or tll( al110unt dltlIllIilll(J i ltlatlpl high ill tili PIY lo Itlllgl 111 aetllllllladie(middot Ill( lopl lillliL 111)(1(1 lIw (ollllil ions of tlil ]lI()(lltlIIIl u ol1tlinpd ipt at l11 11I1 or 1111gt11(1 illt i-1ll1 Ollllll IlPIPltPlltillg 01 p(gtl(pnt of JllUiJtL un tlll 1Hli or (xlla ion rlOI11 II rlll of tisSIll
EIlIlOH COSIIlIHIIO
In Oldpl to H(IIp ill )1lHtPltt pl((iioll illlpIi1I- it i lH((SSHI to slnlldHIdiz(i rigidly 111( Pl()((dlll( 0 illdi(ntpd Oil pnglt- - to J( If lids i dOlH tlip lXIHlinwnlal PIIll is t(middotdllld 10 n ndninlllill
Illlt pl(iioll of (hI ]lIPPllt 1IHllwd Oil til basi of ]llllP llIllJt1 alld Ipsinssollltions call hI jlldgl(J 110111 figllll Hi lileh lio- til HPIlIgl d(intioll oft -illgIP lI1lnSIlIlIIIlnt in lHi((lltagl of Ill( alllOllllt 01 Illhshy1)() 01 lpsins d((PI1I1 iJlld TIl( (1101 PlI(Plltaglt H1( gi (1 101 OJ) to
RUBBER IN 25-ML VOLUMEMG) 004 01 02 03 04
i= I I IZCtOW
fbA ICtU CtCt WW a
01 02 03 04 05 06 07 08 09 100 = RUBBER (PERCENT)
RUBBER IN 25-ML VOLUME (MG) 10 20 30
~ I CtZ
bBOw Ctu CtCt Ww o I~
010 50 100 150 200 250 RUBBER (PERCENT)
RESINS IN 25-ML VOLUME(MG) 10__ __3-0_ 40 50 60 70 60 90 100--_-- 2_-0
Ct~ -r- 1 I OZ
WCt UCt b C wCtW
a o I I 150 250
RESINS (PERCENT) o 10 50 100 200
bllI 1tI W-Yllnl dtd1 ioll I I 11l1 11IlI11 1(111(11 1 III Plll- IlIIIlol1 01 IIim~
bull
bull
bull solution Il basis J o golH of tiSSII (JlILCl-nt (11(11) for (~I) (l)1 til O 1I1
of luhllpl lin 1 III I (I Ill of lUhlJPl nllll laquo I J to 111 nlg of IlSlllgt (Itllillgs on ]iYllyu pllolwh-llrk CO[IJlilll(-(PI with nOHIP Iiltlr lIntl U-lIll allcrture)
RAPID PHOTOlJElRIC DELEHlllNAllON Cn HUBBER AND H1~SINS 33
10 mg of rubber anel1 to 10 mg of resins in a gJ-m1 yolumC For
bull
bull
bull
comparative ptuposes the leslllts arc also calculated on the basis oJvershycentage rubber OL tltsills in 02 gllI of tissul As WOlllL be expcet(d the error increases sOIlHgthlf for 1(lali nmiddotly low COlHell t1llf iOlls oj rllbbeL or resins The curves in figure 1(j s1l0 that ill til(gt Illlge Ol to 10 pCrshyeent of lubber the elTOI rangts Jroll1 abollt Ll to II) ]IlC(lIt abo(~ this mlllc tIlt (ITOl d(((ts(s to (ollsidlItbly ltmiddotss (han 1 1lICPllt of tlH mllollnt ltl((Lmill(d Hil1lilally in tlH (lISl of l(sins analysis (fig 10) the ltLTor is (onsit1eIubly INS than 1 PlLllnt ill (he lallgp of 11 t~) ~() penPII t
In nil ([lSl of lllhblI alld (sins lx(Inltpd tIOIl1 (issups Ol addcltl to tisslle lxtlads (s(( tabhmiddots (i H) illyolillg ll01P o(lllntiolls the eLI01
is hig]wl thun that indilHtld in figllll ((j Im pUIl Ill )])p I tllllllsins solutlOII
COlllUCIIOXFOH IXSOLl-IlLl~ Ilgsqgt(Jg
111 th( Jllo(pdulP ollllillPd 011 paw I till illsolllhll isSII Ipidll( tflpl (xttlw(ioll is (Ptill tlw lIask l(lll till xtlct i l1wdp up to yoltlllH It is not rOllPllipnt (0 IPt()PI qWlIltitati(Ir III(lw[olH a 11(1 pllooll extlnlfs of guuyull I is-lll alll thl1l main t11l111 up (0 YOIUllllmiddot bpCaUHI sllch all additiollal stltp wottld]) tillll-C(JllS11ll1illg Th( Iogiea nll(gtIshynntin is to mnkp tltl lXtlUCt Llld Ipsidup lip to OllillH in till original flask andi llPSStllY 10 llwlno tl OIIpdioll wlHIl (allIlnting [hc llshy
Hults f(JI [hl oll111lC displupd hy till ins()lllbh llsidll( III it l)picat (IXpednHllt (ollsisting of Jhp lppJiea(iolls if was Iollnd llftt at ~iiO ( 02 gill 01 Iuhhll pillS IPill-fl(( lisslI(gt (lollpdll fot llwistUlC ou basis of dlyillp ut lOW 101 ) llOlll-j (lbp(ld only t~ llllUll voiul11P of OOk7D~- OO(lOO(i Ill of lllthyl bolnl(yl 1lIOll( (lplhlli(al-t(Tnltle sp gl () Ii I ll(Hli (j at ~)) -gtitllP tl1(gt 1It101111( () r t is-lIl xt Iadld j sl1lall til( PlIOI dul to Ill(gt insoll1blp Ip~idll is slllall III [0111 ill( wOtk it (all lJp diIpgal(ll(l
]hcon~lIY OF HllIllgl AiO HESIS AIH)gl) TO EXTlIACI OP
GlYlLE TISSlg
Tnl)ll G L(IHpslntillp (ypi(nl llld(~ SllOS (hat all a plngl of HIOK PlI((nt ot lltl pltl( Ilhl)(l acldpd to tllP Itll h iolJut1 InmiddottcJllP xhnet
of guayulp tiSI1( WllS 1l((PllIl Tlli nllintioll flOlll (olllplpU I((OYshy
PIY i within flll pxp(IiIlHuttllIIOI ~illli]llly fnbll Ii llows thn 1111 llYlIUgl of 1O(1~ ])(I(Pllt of gllllYllII 1(-i1l- add(d to II( (pllosol( (xshytrae of IUllY]l t i~HI Is 1l(oPIPI
THl~ (~ Hf (Off Ill of 1111)( J OJ I~il~ lItfI(( In ~(JI1IJk~ Ilf (111 [lI1Il fI2 lIII
0 tlUfllllit i~~I1
Instrument
---- ----~---- bull shy 1(1
Colemun ruono~ltrOUlllt()r 2t) II sJl~ctroJlhOL()lIIeter with 2tJ I iflllllI wnclength Fetting 21 II nntl 0-1111 WU HI hUJl(L _ L U
Ill 7Evolyn photo~lcclrie (olor JU [ imctcr with iO-llIl filler IV (I
H1 0 t I I
llImiddot lUn WII 1011 HIO Wn mil lUulon
10 JIg1111 IUI ml lUl anh Io aLn 111)_I ) III li lU It 2) deg wn2SU DD
Irl JIll II IIr II US II
1110(1 lULa lUI IlK) IJ WU
I( llI Htl tNI 1(111 2tlNI HI 0 221) lllil t2S 0 1~ 10 1~13
In (I 2117 I
10U 1l(J ~ 4 _H_j ___
9middotJIlJ5 10115 10 00 lUU5 flUU 4li (tl03 9(11)
leIlKl 1l~)5 lOOU l1KIr JOIS un 003 OIl Ii
34 lECHNlCAL BULLErIN 920 U S DEPT OF AGRICULlURE
COMPARISON OF PHOTOMETRIC A1D MODJIoIED SPENCE-CALDWfLL METHODS OF RUBBER ANALYSIS
Guayule samples were analyzed by the photQ111etIic method and by bull the modified Spenc(gt-Cnldwell mcthod The values in table 7 represhyselltativ(I of typical results indieate It -atisfactory dcglpe of conformshyjty between the two methods in thl range of tiSSlHH with llHHC than OJ) percent of rubbtImiddot On the bnsis of the amounts determimd the results in this runge for the plmiddotts(nt lIlcthod ayernge apploxinHltely j percent highcr
~LAIII~ 7-(oIllJl(i~on of lltlllrIic (IIri mOtllinl SJl(II(r-(ulri-wall IIIrtlwrl~ of rlrrlIIillillfl 11)1)(1 COIIrll of UI(III
1 Flowers frllm amiddotmonth-oltl nursery plants
YAIIIATJO- OF SIli(LE DETEnt1NATIONS Fnoll TnEIIllIEAN
Rllbbel (Uall8i8-Thc plcCision of thc pLcsent method when gunyule tissues Hr( nnnlyz((1 for rubber may be j udg(d flom I Ill datil presentcd in table H TIl(se dahl -how that thl pplCPlltag( uriation of single determinatiom from nwan yullles with low standllrd enolS ranges from less than 1 to 4 p(gtrlent
R(8in~ wWlsi-r-s lndi(a((1 011 page ~j he INntlts s((uled hy the present phoolllttric nsins llHt hod are not tliltly (olllpalable with those of the grtLVimetri( ncetol1l-cxtlt1(tioll II1etho(l Thjs made it necesSllry to selc(t another lalibllltion staudud-tlll Ipsinous exullate from gullyule shrub-thut gies relatively COllstlllt photometric readshyings (table 5) The resin (olltents of guayule roots branchcs or leavcs usually ran(~e from about) to 1-1middot pelcellt The ple(ision of the present methotf WhCll gUHyule thslllS lIe analyzed for reins may be judged from the datalHmiddotpscllted ill table 9 1h(se data show that the p(lcelltage variatiun of sillgle lhmiddott(Lminntions iLO11 meun ynlnes with low standard NTOrs rangcs from about 05 to 4 percent
bull
bull
bull
bull
bull
RAPID PHOTOMETHIC DElEruIINAlION OJ RUBBEH AND HESINS 35
IAIILE 8-luriation inclieute rubller (mallSM of [1wIIle tissue bll thc 1111O0Illclc metwII
Vnrlntlon~Ilbher I (rom mean
ierCtnl Percelll ~OU -22 ~ 25 +27 ~ 20 +18 ~UO -22---------1_______ 51110 0G6 bullbullbullbullbullbull _bullbull
10 ro ----=ii41075 -01 1000 +11 1010 +13
rlln HI itil 1l9~ 1_ ___ =-~~~
115511 ~ US -111 III II 1575 -13 115 b tiS -I a 111 h WlU +22IIM-(middot bull 11K -1Ja Illi c 1000 +03 1J5H1 W +l)7 ll1imiddot tl 1575 -13
Mcnn 15951 131
1102-11 21fJ() +21l102-h _ ~~)SO -17 1102-c bullbull 21CO +21n02middotd ~OIiO -26
2 r~plusmn Il~ 21151 261 I -~-------bull---__ _~~_~______l-___--_
1 lhe$ 1111($ I1n (or SlIlIIllltS Stpnnltplr PHrilClld IIrtlrdlng 10 1hr prollIlIlr( OIiIIiIl(o(I on Imgt$ 4 to IC ~tcond nUlI1 hlr r(J)[ltnts stl1ndnnl llrrot of tilt 1I1(1111
1_1l1~ n-J(lri(iot in relli(Upound rpoundsins (lllalIsfs of VIOJII( lixsue b1 the lhomillric lII(lloli
-- ---~--- - __-------- shybull I I I I Varlgttton
_________~___ ~~lu_n_Jl_Q_~~~_____ ______I__~_o~S_J frOID lDean
Percent Percentgt458-1 ~65 +41IWtl-li 130 -a2Hli8c aliO +26S41i8-d bull 130 -32
1(-011 34I10Olifgt __ bullbull __ ~--====
li-9~2n 881) -06 li-9~2-b Si5 o ~HH2middot(middot S i5 -6$-H2middotd 000 +1
8851 054
O i5 +6 9 i5 +6 950 -20 U75 +6
H-liG3o-n bull -1 n-li6~b bull __ _ -IH-IWH +4H-l61511 bull -1
1tmiddottlU
62~-lI __ 62~-b ij24-( bull OH-Ji
(-Ull
I rll(St oluls nre tor separately ~xlrflCled SllllllllCS IlctOrdlug lO procedure outllned ou pages 4 to 10 i Secoud number r~prtgeulS stulldMd error of lIe menn
36 TECHNICAL BULLETIN 920 t ~ DEPT OF A(]RICCLTCRE
ReUUER A~ALYSrS I~ CRCOE-RcuUER PROOCCTS
Sew rapid photometric m(lthod~fol the ddellllinttion of rubber and reii Hi ill uaYllp ti--ut htp lllell pIPHnl pd oil pag( ~l to In A brief H1111111tlY of It similar rnpid llHthod fm 1I1hb~rllnltlysis of u1lulcanizNl tlIldp lubbll pl(Hlmtlt whielt i~ bn-(tldo on the prill o
ciples dehtilcd tlllLe follows Duplltate nt-gm sllmph of the finely cliyiliNl IlInttlitiup wlirllll out [~ei-()l (all hl lIf((tinmiddotjv INd to lt1iyidl till alllpl) TIll kltolll-olubll portion of till )111(11( tlrc di-olved a- indh-Htpd fot thmiddot lllnkill~ of -tlllHlunlluhhll olutiou Oil Pt 1II hut tIl IUlIp Hn lIn l-fplImiddotd 10 lHI-ml rolllllltti( fln-k antil1ltld(lup to Olllll1l The bnlulUp or till JllO(ldllll i- thatutlilllll on paWs -1- 1 IHI Ii 111( 1(111 1- nIP IXPIP--pd nil til IHi or Iw oligiJla w(lullt of I Ill (I11l1p-I1l11Ilt1 1)(0(11(1
Hupitl PlllimiPJojgtiWllllllllh llIltllOd~ fOJ Ihl llPtlmiddotminntion of ImiddotUlJbll tlnd 1(-illo- ill -111111 Illllph of gutlYllll tiUl IIll dl-eli)ed 111() IlltlY d~o Ill nltlI1lld fOl III Iwl Illhlwl- and l~iJlmiddotb(lLiJlg plant TIllt l[Olllhup hns nlo b(l1l ntuptpl fot IIH lltlIll1illtltioll of lllhbpl ill 11lHhrublwl Pl(Jdlld~ HIIl 1111 hI ndaptld JoJ IIll ann lysis of ynt1J(gt( ic lllbbl[- The llllthmb HIP 1gtn(11 fill tIll fol1owill plimiph- III Grinding
tIll PIOPlly driPl t i~lIl 01 Ul tillg tIll pnHhHt to tll l((lllilllllh~lel of filWlH-- til plllllit qIHlIllilnth( lXIIHtioll 01 IIlbhlI 01 1(--IJl- () llsing oXWllutld olnuh (kttoJls IIt(talp and() fllltil for LIbbel and IH(ltIlIlyptIJllIllIoolYlnJld-o flJllh 101 niJlsl with t(lathelr high IlPililig points 111 to n C) l]olle or in mixt tIll thllt Pll mit tlll rnphllxututioll of luhll(l OJ [middot(ill ill ~() to (l mi1lutp It r(latiwly high 1lllIllllltlltP Ill to 1~11 ) l) lllllipitntillu till luhblI OL Imiddot(ill frolll aliquot () f till oltn ion I IlIlllI-i () f Hlltabhmiddot pl(~(i]litallt (willifhmiddotd lthmwl fOl IIlhlHI Hild llitlifild lllr fOJ JP-illl t~) IIlHkillphotollllliilPIIIIiIlof PlllPlltal of liht tLaIlS mittUl(P lIftlI IlIlbll (II Il in PIlipitalioll 11 II WI( Iplllh thnt (limiJlall till PIIOl dill 10 xtralllOlh (0101 (till dptl1minntinll Iph jill 011 tIll dtwlopllIlJIl of H HIli rOI1ll tlllbidity 111 hpl than I (olot rI
jJlIlpOP-ofallnlyi-I ( p(lllil1thb IIllijOI1ll turbidity or 1llt[lIinmiddotd d(ltl of jgtIp(ii(JlI l)~ lIltlkillU tIl plllltollllmiddottri( ntdillU al tandinu tiJlH~ (dlllilll wlli(h IhlllH(lill-- IP 1llutinmiddotly tnhll) t1ll1t an hlsl~1 oil the (oJlItlIlllItion of IIlhlHI Ill I(ill (lIPIipitat((L
TIll -I(p ill till jll()(Plhul HIP 1-- follOylt (1) 1l~UIIL uJ1lplls of thwl UJfJlllHl (II tliddl(l HUt dlipd 11Illtplial an lXIllltel with11 Ill of till nlnll ill t (oU tlllltIPlll[gtPImiddotatlup oil Iath at 11 Cbull fol 11 minutl I) iIP1lIin(middot(lohd til( (XUtllhllll Jltldl lip to It middotml ynlmlll til( (nlifild by (Illlifllgiuu HlId thlPl IlI nliql1ot of tIl (IalioPlllxUlltl nll Uillltlmiddotll(t to l-llll OIlIIlIllril fiuk- (1) For a trial Ilnditlg 0111 III tlll j liJmiddot~t IllHII IIjI to Ohlllll with lilt Pll shy(ilitnnl a 1(11 it 111 (Dod fill llli lIut ( ptotoJIIltlil IPtlllillg-- of pllllntnl or liuht tlUtllIlillal(I oil n (lpel OphotnJlllllI at rase hng-tlt (If 11 llJ Ill Ol It lollllil1lPtImiddott lloyidld with tIll P10]11 I 1110110shy
Ihlolllltt hmiddot Ii1llI Olllhi lIatioll for -1IpItillg UJlproXilll1l tply Wtl P ]Plwth )0 mp are HHlltk TIll Illldillg lliJtaillld fol tIlt 4-milutl tliall(~ll-
bull
bull
bull
RAPID PHOTO~IETRIC DETERIINATIOX OF R(BBER AXD RESINS 37
ing are referred to a table of equhmiddottllut~ previously p1(pa1elt1 on the
bull basis of 4-minute reac1inJ~ for tilE nmge of lot1telltlatiol1- of rubber or resins to bE elHOlll1t(led tmd gidn thtmiddot -tnnlillfr tillIP fill rUbbEt or resins aiter prE(ipitlltiol1 lwfolE photoIllNliI j(tltlill1 un IUade The r(middotnmining dllplllatt aliquot lll then HHllil up te ol1l1Jle and lpoundadillg ale marle ut the -tandillfr tiUlE iudklltll ill rhl tall1lmiddot for the final r(adillg~ -1) 111( milli1lnm or p(tCPlltllt- of lllhbpL (II 1(-in pr(s(nt are rpadholU a prlpan(l table of lquiltlput for tlll photoshymetric readings h1~l(l ill pnell e1-E on pxpPlilmlItal lhln 1111(1 u-ing as stimtlltlds pure luhbll in 1l1bbtl milllYb aIHI guaYllh ll-ill- lxIHlatt~ in resins detNIl1111lttion I
LlTERATlRE CLTED
(1) lUnSbull 1fl36 THE mURMIXTIOS IIF IOTA RE I III OOl THER llT~II
F1 bullrol IlY U(T1l0fll UfSlfi ~rrnrl r flm lt1 KEYS TI Bill Chern 114 44J-l59 illns
t1 ~ICPHHlObullbull T 1J3bull~ lUTHOO roa THE PtRInCAnu Or a(lIUl IRrIlHU It of TIn
PLRIHEU Htllllflt [ i Bill lallllall 111 Rmiddot 711middotj iIlus
I ) RHBERG P B Ul5 A METHIlO Or ~u(ronrll-nl Hi tIII rUIl[1 f71 ii illlI
bull 14 Hoss W flbull and HARDESTY J O
llH IR1ltDII Of HfITilIZfmiddotR DllIJS ltt 1 Yl fll Off gI bern JIIIlI i ~middotmiddotlf IIl
101 SPEltCE D nnd CuoWELr ~I L 1933 DETER~n-ATIOo OF RtBBER Ii nrllllpoundRBfR Iusr 1uI II1 amI
Em~ifl cttIliIa~~ r Ell i 71middot7i l11 (HI WALTER E D
1U44 ISO~nlS OF PRTlltSrr 1trHpoundV bull l UI n W lHHt (Tnmiddot 1ETS FROM GiYI l~iIl lItr Clttrn SII J UI titJ middotn9--C1 ilIu
17 J YOEbullbullr H lO~( roLORIlETRT 771 IPmiddot nl -W Yurk f H Plrwptric hmica
naly-II rimttry lUll XphHHlnmiddot~ y 1 1
11
HI) ~ fPHELolzTRf 57 111bull Lin xw Yk t H lt PhmeHt CblUlmiddot ila AnaiY~l~-(H lithrry and XIhmiddotILpfIY Y wirh enomiddot rrJlllrjr hy H KtlJnJU11 I
t~1I --- and ~ARVER L 1f41 nlua-w ~in L liLhr IS IP ll~ XIW Yrk
bull For-sale by th~ ~a~fr1nt~nf1ent Dt~c~~ogtnts-~ s t1i rArnn~ut Pn~~~ tJffieshy
Washington 5 D C bull Pl lU ~nts
28 QECHNICAL BULLEQIN 920 U S DEPT OF AGRICTTIIlURE
16~==========================115 shy
14 bulli= 13 z ~ 12
ffi II Q
10 c w 9a w
8gto () 7w a
6a w
5en III ) 4 a
3
2
A 00 5 10 20 30 60 90
14~------------------------------------------- bull13
i= 12 z w II ()
a 10 w Q
9 c w 8 a w 7gt o () 6 w a 5 If)
z 4 If)
w 3 a
2
o+B~~__~__~____________~__________~ 5 10 20 30 60 90
HEATING TIME (111 NUTES)
lllGUltE 13-lDffect of time o( lICntillg O2-gm samples of gunynle tissue with solYlIt nt llfio C on lo(OVl)ry of lllhlJer alld 1Isim Lt HlIhblL extracted with methyl isohntyllwtone B resins Cxtll1cted with aCftonyla(etonc-cellosolve 3-7 bull
chlorophyll are weighed along with the resins in the acetone extruct but are not estimated by the present photometric method (fig 0) 1he use of a diffeJent stanclttrd waS therefore indicated
bull
bull
bull
RAPID PHOTOMETRIC DETERMINATION OF HUBBIm AND HESINS 29
The resins standard selected is based on n relatively pure source of resins the rcsinous exudnte 011 the stems of guuyule plants IJldimishynary expeliments with the resi nouS cxuclate from diffcrellt gllayu Ie strains of various ages indicatc nHlt there is little YaLiation in this subshystance on the basis of Colorimct(r readings 011 2-mg aliqllots of 01shypercent solution in It 2i-ml volume (tabl( li) Expelilll(lnts have shown that the air-dried (xuclate contains 3RtOH p(Ic(nt of -volatile matter This material is l(latiyt~ly stablp ill (OlllpoBition and is npshypurpntly on ly slight ly hygroBcopic as shoWIl ill Ia bl(1 1 Tlrp Ipsinolls exudate may be jJleplpd in two wayi-i fl liSP as a stallClHld-(l) the clpan exudate is clripd iol Ghouls at ()1deg C at W indlPs of a(lIum Hnd aftclbCinOglOund ill a molfalis 1)I(spI((I intn airtight COllilinel OL
(2) tllP Cx7lclate is clissolllt1 ill a(lhllll and filtplpd PlactieaJlyall of the acetm1l is thpn lYapolntwl olt OPI a stlam or atCt hath and Ow residue is dripd ground an(( PI(sPIld as ill tllp fin lllethocl Tlwse two prepalHtlolls a1( (ompalpd in ta hlp ) 111( (((tails fOl ~t()lil1g the resins standald and (onstlllcting the calibration CUITPS alc given Oil page ]2
lAIIIg fi-CUIIIllrsoi (lJ lIr-dr(1I IIIIi 1((11 II II-()I-tr((l l(sil~ 11111111(8 of I II 1111Ie
[Colorimetric rrndill~s 011 1~I11 phulll(Iclrie eolorillJct[lr with i~()middotmll (100- to iiOIIIIl) fillcr [lnd 5-1111 lIperture preeipitantl part ofO5middotPIrctllt 10 to 5 paris of IIOj
nupliclllc(oloritwt([
nIl(lin~s (hIlSlcAg~ ofSlmillXo JrNliltlCllt of fPsiJI$ L1Xtlrlntp on 2 IIIg ofplanls fllsins (XIHIIlt~Jwr 25-1111 vol
tII1(1) 1
leflTs Various _ bull ____ bullbullbullbull 3-9 Colll)Josiltrlairmiddotltlricfl bullbullbull nf)2 002
])0____ bullbullbull _bull __ _ bullbull ~-l Composilld (ri d at n5 C in aUmiddotimh lWUUllJ for l (jOuj(ja hours])0______ bullbullbull __ bull ___ bull 3-0 COJIlpositld disso]NI in neptolll f1l1erNl fl(lf()ll( GGO i(jO (Ivaporntld olT OV(1r Stpl1l11 halh TesidlH drl(ld I1t fi5deg ( ill anmiddotinch VIl(Unlll for 0 houlS bull
middot106 __ bullbull _ Jir~c1rild_~_~_ _~_ ~_~ _ ~ ____ _ __ _ OUu GOifina_~ ~ _ ~~_~ ___ _ _fln~ ~~ ~ ___ ~ __ 6(imiddotI tiliA H)[_ ltlu bullbull i18 tisSflOabullbullbullbull__ bullbullbullbullbullbullbullbull lt10bullbullbull _ tillO llitO406__ bullbull __ bullbull __ bull __ __ lt10_ Utl2 fon591_ fo__ bull liGa oOa 406bullbull _ __ lt10bullbullbull_ li5S OM
j Ph( vnluls in Uw Inst COIUIIlIl indieatp thnt gunyulp fesinous (IIHlnt( wlwtlwr dfircl hi Yn(tlLJ1l1 wilh L~ perc(nt loss of volntllt wutl pr or tWl c1rild giVPd npproxil1lnh1ly t Iw snllw colorinwtCr rNHiing- 011 till busis of aliquot~ cOlllniuiug 2 IJI~ of flsillS lXIHlntp l)tIf 25-mI volultl( Ihil- illdicate~ thl11 Uw UITW IJ1flS~ of olnshytile mntl(f prt~(iJlitnt(d gins npproxilllntlly Uw $1II1l (oiOfirnl1tlf ftudiTlJs ns tho ftsidtw A pnlill1jllaf~middot (XIlltrinllnt indicutls thlli th VUllltill muller l(lIlSists of thl Ilrplne oil fmcl ion I5-(1Il gtnplls or rlsitlOtlS (lxudntll gnvll by stPll1U distillation nn Uefllgl of 011111 of jl(lfPlIW oil with npproximHte tilllsity (If OHIi lind lhus rrprlsll1ll( IlPIJroximllt(I~ 01 Jerccllt Of t he original weight 1hls lllrClnlage complrcs wllh 38 llltrC(ntlost by drvinI( in IICllnllJ
aSplusmnUH perceilt or orlginlll weightlosl
The wailnble illfolJllntioll on tlH (ow-JitlPllts of the gunYllle r(~shyillOllS exudate alld tl1( HeetOlIP ext act of gaylp ti~slw is sllIllmarized in this paragraph lYalttI (u) alld also Hangcn-Slllit lind his coworkshyers 16 reported that 20 percent of the resinolls exudate from gUltyulc stems is parthenyl cinnamaie (CHuOH=CHC020 11JI2r) Steam disshy
15 (OIlIJIIIIUicatioll flom A T Haai(II~l11it llId (0011(11 Calif0111 ill Tnfiitnte of Tccllllology Past(IlIJI Jhps( wOlken al Htud~ing the COTlHlitlllllts of the acetone extract and other conlltituellis of guuyule
30 TECHNICAL BULLETIN 920 U S DEPT OF AGRICULTURE
tillation of similar resinous exudate in the writers laborntory has yielded approximately 4 percent of the whole as the telmiddotpene oir fracshytion Haagen-Smit and his eoorktrs nportec1 thttt about 25 percent of the acetone extract from guayule branches is parthenyl cinnamate and 6 percent of the bark (ltortpamp-phlotm) extraet is parthenyl cinshynamate These workers fm-thcI reported that 25 lwletnt of the nc(shytone extract frolll bLllllches is a compound with the tlI1pilicaL formula CBoH400a 1 percent is a compound llwltillg at 2P to 2T5deg C and 1 percent of the extract from the ]eav(s is tl (olllpoulld nwlting at 100
to 1710 1Valtei (6) reported that 3 to -l perc(nt of the tI(eton( txtract
of leaves and flowering StPIllS of guayulc eonsists of waxlike substances soluble in olgallic soln~nts but insoluble in at(l and (on(ent1llted H 2S04 The flactions mentioned on the basis of (onHLTutle esti shymates of amoullts actually isolated tlecoullted for about H ptIcent of the totalncetollt~ so]ubles extracttd from tll( guuYllle 11 rub The other constituents ltlilaill to be i(](ntifi(d
RUBBER AND RESINS CALIBHATION CVHES
Typical culibndioll Clllves iol Iuhbpl and I(sins bas(d 011 (ldtLminttshytions made nccoLdillg to the plocCdmC outlin(d 011 pages middotb to 1G arc shown in figulPS 5 and 1+ The spCdlopliotoll1lttL en (OIOIjlllctCI readings are plottCd on s(lIlilogalitllllliC pappi ag-ail1st (Il 11IbblI (011shy
100 ~ 90
80 ~ 70 ~
z 1amp1 0 II 1amp1 IL
1amp1 0 Z
60
50
40 ~ltI 30 ~ en z ~ ltI II ~ 20 C) ~ oJ
10 o 2 3 4 5 6 7 8 9 10
RU8BER IN 25-ML VOLUME (MG)
bull
bull
bull FI(lURE 14--Ctlihration curve fotmiddot gllftYlIlc lubb01 (Hct(lings Oil COIPIIHlII tlOl1hl(
monochromator SlCClrophotolllet(r with 7fiO-11IL Illtel alld Hllp Wll ( IHlll()
bull
bull
bull
RAPID PHOTOMETRIC DETE~MINATION OF RUBBER AND RESINS 3]
centrations From a casual inspection of these CUlTes it would appeltr that Beers law does not hold Actual tests indicitted that Beers law was applicable only within a narrow range in the upper portion of the curves The analyticlil results on the basis of photornetric readings nre therefore calculated by direct reference to calibration curves or from reference tables of equivalent values bllscd on the cnlibllltion curves
Calibration curves for kok-saghyz alld heyea lI11tulltl rubbers and Buna S (GR-S Chem Gum IV Goodyear) and butyl (GR-I Standshyard Oil Co Protoc) sYJlthetic rubbers are hOWllil1 figure 15 The samples of kok-saghyz rubber were furnished by the Diyision of Rubshy
100
90 ~I) ()
z 0
1amp1 a
~ a
80
70
60
s 1amp1 ~ ~ 0 ~ KOj-SAGHYZ 0 l Il
50
HEVEA~ ~
40
100
90
~ 0 80z Q 70a Co)
a 60 ~ 0 0 x 50Il
40 ~----~~----~------~------~------~--~ o 2 3 4 5
RUBBER IN 25-ML VOLUME(MG)
FmUIlE 15-CaJiblation curves fOl kok-snghyz h(YCII Bunn S lind butyl rubb~ls (Readings on gy((yn photoelectric colorimeter with i20-lIIp filtpl and 6-ml aperture)
32 TECHNICAl BUIJLETIN [)20) 1 S DEP1 OF AGrnCUIlfURE
Iwt Plant JIl(I~t ignlioll of thi BlII(un and (1( l))(parcd according to 11( SPltI1((-Culd (]] (6) PIO(((lllll Hlpt pal( CLPPe was (xtmch(L with acetone blI()Ieit W 1I(gt(11l a ttnlldal(l
SEXSlllVllY Ol~ llETJIonS
By lip pIO((l(II11P olltlillP(l 011 ]Hlg( +n Iowa (lOOl IIIg (11 1111i(l0shygmm (gHlllllla) of 1hblI ill a 2)1111 yoltll1ll (all )(gt dltpltld Oil tltl Col(man (lohlP mOIlWhlOl1lHlOl l-I)((t 101 l1lOt 0111 ci( I ill1ilnlly 001 mg of Iublwr ill a 2J-1ll1 n]ulllP Illay bl Ilad Oil till EnI)1I photoshyllectlie (O]oLillllt(I Thll ya lllll- 011 tilt IHl-i- (J I (xl ad iOI1 fmlll 02 gill of til-lI tH(JI(lillg to tllP -lllndal(l jll()(pdull 1(PIPStlIt IlO()2J tlnd 002) P(IT(lIt of llIbl1ll IPI)(((inly bull1t1lollgh -lI1t low allils can be d((d(middot(1 il lIoullt1 Ill IPtllizpd thnt till PIIOl ill PlI(Plltng( or tll( al110unt dltlIllIilll(J i ltlatlpl high ill tili PIY lo Itlllgl 111 aetllllllladie(middot Ill( lopl lillliL 111)(1(1 lIw (ollllil ions of tlil ]lI()(lltlIIIl u ol1tlinpd ipt at l11 11I1 or 1111gt11(1 illt i-1ll1 Ollllll IlPIPltPlltillg 01 p(gtl(pnt of JllUiJtL un tlll 1Hli or (xlla ion rlOI11 II rlll of tisSIll
EIlIlOH COSIIlIHIIO
In Oldpl to H(IIp ill )1lHtPltt pl((iioll illlpIi1I- it i lH((SSHI to slnlldHIdiz(i rigidly 111( Pl()((dlll( 0 illdi(ntpd Oil pnglt- - to J( If lids i dOlH tlip lXIHlinwnlal PIIll is t(middotdllld 10 n ndninlllill
Illlt pl(iioll of (hI ]lIPPllt 1IHllwd Oil til basi of ]llllP llIllJt1 alld Ipsinssollltions call hI jlldgl(J 110111 figllll Hi lileh lio- til HPIlIgl d(intioll oft -illgIP lI1lnSIlIlIIIlnt in lHi((lltagl of Ill( alllOllllt 01 Illhshy1)() 01 lpsins d((PI1I1 iJlld TIl( (1101 PlI(Plltaglt H1( gi (1 101 OJ) to
RUBBER IN 25-ML VOLUMEMG) 004 01 02 03 04
i= I I IZCtOW
fbA ICtU CtCt WW a
01 02 03 04 05 06 07 08 09 100 = RUBBER (PERCENT)
RUBBER IN 25-ML VOLUME (MG) 10 20 30
~ I CtZ
bBOw Ctu CtCt Ww o I~
010 50 100 150 200 250 RUBBER (PERCENT)
RESINS IN 25-ML VOLUME(MG) 10__ __3-0_ 40 50 60 70 60 90 100--_-- 2_-0
Ct~ -r- 1 I OZ
WCt UCt b C wCtW
a o I I 150 250
RESINS (PERCENT) o 10 50 100 200
bllI 1tI W-Yllnl dtd1 ioll I I 11l1 11IlI11 1(111(11 1 III Plll- IlIIIlol1 01 IIim~
bull
bull
bull solution Il basis J o golH of tiSSII (JlILCl-nt (11(11) for (~I) (l)1 til O 1I1
of luhllpl lin 1 III I (I Ill of lUhlJPl nllll laquo I J to 111 nlg of IlSlllgt (Itllillgs on ]iYllyu pllolwh-llrk CO[IJlilll(-(PI with nOHIP Iiltlr lIntl U-lIll allcrture)
RAPID PHOTOlJElRIC DELEHlllNAllON Cn HUBBER AND H1~SINS 33
10 mg of rubber anel1 to 10 mg of resins in a gJ-m1 yolumC For
bull
bull
bull
comparative ptuposes the leslllts arc also calculated on the basis oJvershycentage rubber OL tltsills in 02 gllI of tissul As WOlllL be expcet(d the error increases sOIlHgthlf for 1(lali nmiddotly low COlHell t1llf iOlls oj rllbbeL or resins The curves in figure 1(j s1l0 that ill til(gt Illlge Ol to 10 pCrshyeent of lubber the elTOI rangts Jroll1 abollt Ll to II) ]IlC(lIt abo(~ this mlllc tIlt (ITOl d(((ts(s to (ollsidlItbly ltmiddotss (han 1 1lICPllt of tlH mllollnt ltl((Lmill(d Hil1lilally in tlH (lISl of l(sins analysis (fig 10) the ltLTor is (onsit1eIubly INS than 1 PlLllnt ill (he lallgp of 11 t~) ~() penPII t
In nil ([lSl of lllhblI alld (sins lx(Inltpd tIOIl1 (issups Ol addcltl to tisslle lxtlads (s(( tabhmiddots (i H) illyolillg ll01P o(lllntiolls the eLI01
is hig]wl thun that indilHtld in figllll ((j Im pUIl Ill )])p I tllllllsins solutlOII
COlllUCIIOXFOH IXSOLl-IlLl~ Ilgsqgt(Jg
111 th( Jllo(pdulP ollllillPd 011 paw I till illsolllhll isSII Ipidll( tflpl (xttlw(ioll is (Ptill tlw lIask l(lll till xtlct i l1wdp up to yoltlllH It is not rOllPllipnt (0 IPt()PI qWlIltitati(Ir III(lw[olH a 11(1 pllooll extlnlfs of guuyull I is-lll alll thl1l main t11l111 up (0 YOIUllllmiddot bpCaUHI sllch all additiollal stltp wottld]) tillll-C(JllS11ll1illg Th( Iogiea nll(gtIshynntin is to mnkp tltl lXtlUCt Llld Ipsidup lip to OllillH in till original flask andi llPSStllY 10 llwlno tl OIIpdioll wlHIl (allIlnting [hc llshy
Hults f(JI [hl oll111lC displupd hy till ins()lllbh llsidll( III it l)picat (IXpednHllt (ollsisting of Jhp lppJiea(iolls if was Iollnd llftt at ~iiO ( 02 gill 01 Iuhhll pillS IPill-fl(( lisslI(gt (lollpdll fot llwistUlC ou basis of dlyillp ut lOW 101 ) llOlll-j (lbp(ld only t~ llllUll voiul11P of OOk7D~- OO(lOO(i Ill of lllthyl bolnl(yl 1lIOll( (lplhlli(al-t(Tnltle sp gl () Ii I ll(Hli (j at ~)) -gtitllP tl1(gt 1It101111( () r t is-lIl xt Iadld j sl1lall til( PlIOI dul to Ill(gt insoll1blp Ip~idll is slllall III [0111 ill( wOtk it (all lJp diIpgal(ll(l
]hcon~lIY OF HllIllgl AiO HESIS AIH)gl) TO EXTlIACI OP
GlYlLE TISSlg
Tnl)ll G L(IHpslntillp (ypi(nl llld(~ SllOS (hat all a plngl of HIOK PlI((nt ot lltl pltl( Ilhl)(l acldpd to tllP Itll h iolJut1 InmiddottcJllP xhnet
of guayulp tiSI1( WllS 1l((PllIl Tlli nllintioll flOlll (olllplpU I((OYshy
PIY i within flll pxp(IiIlHuttllIIOI ~illli]llly fnbll Ii llows thn 1111 llYlIUgl of 1O(1~ ])(I(Pllt of gllllYllII 1(-i1l- add(d to II( (pllosol( (xshytrae of IUllY]l t i~HI Is 1l(oPIPI
THl~ (~ Hf (Off Ill of 1111)( J OJ I~il~ lItfI(( In ~(JI1IJk~ Ilf (111 [lI1Il fI2 lIII
0 tlUfllllit i~~I1
Instrument
---- ----~---- bull shy 1(1
Colemun ruono~ltrOUlllt()r 2t) II sJl~ctroJlhOL()lIIeter with 2tJ I iflllllI wnclength Fetting 21 II nntl 0-1111 WU HI hUJl(L _ L U
Ill 7Evolyn photo~lcclrie (olor JU [ imctcr with iO-llIl filler IV (I
H1 0 t I I
llImiddot lUn WII 1011 HIO Wn mil lUulon
10 JIg1111 IUI ml lUl anh Io aLn 111)_I ) III li lU It 2) deg wn2SU DD
Irl JIll II IIr II US II
1110(1 lULa lUI IlK) IJ WU
I( llI Htl tNI 1(111 2tlNI HI 0 221) lllil t2S 0 1~ 10 1~13
In (I 2117 I
10U 1l(J ~ 4 _H_j ___
9middotJIlJ5 10115 10 00 lUU5 flUU 4li (tl03 9(11)
leIlKl 1l~)5 lOOU l1KIr JOIS un 003 OIl Ii
34 lECHNlCAL BULLErIN 920 U S DEPT OF AGRICULlURE
COMPARISON OF PHOTOMETRIC A1D MODJIoIED SPENCE-CALDWfLL METHODS OF RUBBER ANALYSIS
Guayule samples were analyzed by the photQ111etIic method and by bull the modified Spenc(gt-Cnldwell mcthod The values in table 7 represhyselltativ(I of typical results indieate It -atisfactory dcglpe of conformshyjty between the two methods in thl range of tiSSlHH with llHHC than OJ) percent of rubbtImiddot On the bnsis of the amounts determimd the results in this runge for the plmiddotts(nt lIlcthod ayernge apploxinHltely j percent highcr
~LAIII~ 7-(oIllJl(i~on of lltlllrIic (IIri mOtllinl SJl(II(r-(ulri-wall IIIrtlwrl~ of rlrrlIIillillfl 11)1)(1 COIIrll of UI(III
1 Flowers frllm amiddotmonth-oltl nursery plants
YAIIIATJO- OF SIli(LE DETEnt1NATIONS Fnoll TnEIIllIEAN
Rllbbel (Uall8i8-Thc plcCision of thc pLcsent method when gunyule tissues Hr( nnnlyz((1 for rubber may be j udg(d flom I Ill datil presentcd in table H TIl(se dahl -how that thl pplCPlltag( uriation of single determinatiom from nwan yullles with low standllrd enolS ranges from less than 1 to 4 p(gtrlent
R(8in~ wWlsi-r-s lndi(a((1 011 page ~j he INntlts s((uled hy the present phoolllttric nsins llHt hod are not tliltly (olllpalable with those of the grtLVimetri( ncetol1l-cxtlt1(tioll II1etho(l Thjs made it necesSllry to selc(t another lalibllltion staudud-tlll Ipsinous exullate from gullyule shrub-thut gies relatively COllstlllt photometric readshyings (table 5) The resin (olltents of guayule roots branchcs or leavcs usually ran(~e from about) to 1-1middot pelcellt The ple(ision of the present methotf WhCll gUHyule thslllS lIe analyzed for reins may be judged from the datalHmiddotpscllted ill table 9 1h(se data show that the p(lcelltage variatiun of sillgle lhmiddott(Lminntions iLO11 meun ynlnes with low standard NTOrs rangcs from about 05 to 4 percent
bull
bull
bull
bull
bull
RAPID PHOTOMETHIC DElEruIINAlION OJ RUBBEH AND HESINS 35
IAIILE 8-luriation inclieute rubller (mallSM of [1wIIle tissue bll thc 1111O0Illclc metwII
Vnrlntlon~Ilbher I (rom mean
ierCtnl Percelll ~OU -22 ~ 25 +27 ~ 20 +18 ~UO -22---------1_______ 51110 0G6 bullbullbullbullbullbull _bullbull
10 ro ----=ii41075 -01 1000 +11 1010 +13
rlln HI itil 1l9~ 1_ ___ =-~~~
115511 ~ US -111 III II 1575 -13 115 b tiS -I a 111 h WlU +22IIM-(middot bull 11K -1Ja Illi c 1000 +03 1J5H1 W +l)7 ll1imiddot tl 1575 -13
Mcnn 15951 131
1102-11 21fJ() +21l102-h _ ~~)SO -17 1102-c bullbull 21CO +21n02middotd ~OIiO -26
2 r~plusmn Il~ 21151 261 I -~-------bull---__ _~~_~______l-___--_
1 lhe$ 1111($ I1n (or SlIlIIllltS Stpnnltplr PHrilClld IIrtlrdlng 10 1hr prollIlIlr( OIiIIiIl(o(I on Imgt$ 4 to IC ~tcond nUlI1 hlr r(J)[ltnts stl1ndnnl llrrot of tilt 1I1(1111
1_1l1~ n-J(lri(iot in relli(Upound rpoundsins (lllalIsfs of VIOJII( lixsue b1 the lhomillric lII(lloli
-- ---~--- - __-------- shybull I I I I Varlgttton
_________~___ ~~lu_n_Jl_Q_~~~_____ ______I__~_o~S_J frOID lDean
Percent Percentgt458-1 ~65 +41IWtl-li 130 -a2Hli8c aliO +26S41i8-d bull 130 -32
1(-011 34I10Olifgt __ bullbull __ ~--====
li-9~2n 881) -06 li-9~2-b Si5 o ~HH2middot(middot S i5 -6$-H2middotd 000 +1
8851 054
O i5 +6 9 i5 +6 950 -20 U75 +6
H-liG3o-n bull -1 n-li6~b bull __ _ -IH-IWH +4H-l61511 bull -1
1tmiddottlU
62~-lI __ 62~-b ij24-( bull OH-Ji
(-Ull
I rll(St oluls nre tor separately ~xlrflCled SllllllllCS IlctOrdlug lO procedure outllned ou pages 4 to 10 i Secoud number r~prtgeulS stulldMd error of lIe menn
36 TECHNICAL BULLETIN 920 t ~ DEPT OF A(]RICCLTCRE
ReUUER A~ALYSrS I~ CRCOE-RcuUER PROOCCTS
Sew rapid photometric m(lthod~fol the ddellllinttion of rubber and reii Hi ill uaYllp ti--ut htp lllell pIPHnl pd oil pag( ~l to In A brief H1111111tlY of It similar rnpid llHthod fm 1I1hb~rllnltlysis of u1lulcanizNl tlIldp lubbll pl(Hlmtlt whielt i~ bn-(tldo on the prill o
ciples dehtilcd tlllLe follows Duplltate nt-gm sllmph of the finely cliyiliNl IlInttlitiup wlirllll out [~ei-()l (all hl lIf((tinmiddotjv INd to lt1iyidl till alllpl) TIll kltolll-olubll portion of till )111(11( tlrc di-olved a- indh-Htpd fot thmiddot lllnkill~ of -tlllHlunlluhhll olutiou Oil Pt 1II hut tIl IUlIp Hn lIn l-fplImiddotd 10 lHI-ml rolllllltti( fln-k antil1ltld(lup to Olllll1l The bnlulUp or till JllO(ldllll i- thatutlilllll on paWs -1- 1 IHI Ii 111( 1(111 1- nIP IXPIP--pd nil til IHi or Iw oligiJla w(lullt of I Ill (I11l1p-I1l11Ilt1 1)(0(11(1
Hupitl PlllimiPJojgtiWllllllllh llIltllOd~ fOJ Ihl llPtlmiddotminntion of ImiddotUlJbll tlnd 1(-illo- ill -111111 Illllph of gutlYllll tiUl IIll dl-eli)ed 111() IlltlY d~o Ill nltlI1lld fOl III Iwl Illhlwl- and l~iJlmiddotb(lLiJlg plant TIllt l[Olllhup hns nlo b(l1l ntuptpl fot IIH lltlIll1illtltioll of lllhbpl ill 11lHhrublwl Pl(Jdlld~ HIIl 1111 hI ndaptld JoJ IIll ann lysis of ynt1J(gt( ic lllbbl[- The llllthmb HIP 1gtn(11 fill tIll fol1owill plimiph- III Grinding
tIll PIOPlly driPl t i~lIl 01 Ul tillg tIll pnHhHt to tll l((lllilllllh~lel of filWlH-- til plllllit qIHlIllilnth( lXIIHtioll 01 IIlbhlI 01 1(--IJl- () llsing oXWllutld olnuh (kttoJls IIt(talp and() fllltil for LIbbel and IH(ltIlIlyptIJllIllIoolYlnJld-o flJllh 101 niJlsl with t(lathelr high IlPililig points 111 to n C) l]olle or in mixt tIll thllt Pll mit tlll rnphllxututioll of luhll(l OJ [middot(ill ill ~() to (l mi1lutp It r(latiwly high 1lllIllllltlltP Ill to 1~11 ) l) lllllipitntillu till luhblI OL Imiddot(ill frolll aliquot () f till oltn ion I IlIlllI-i () f Hlltabhmiddot pl(~(i]litallt (willifhmiddotd lthmwl fOl IIlhlHI Hild llitlifild lllr fOJ JP-illl t~) IIlHkillphotollllliilPIIIIiIlof PlllPlltal of liht tLaIlS mittUl(P lIftlI IlIlbll (II Il in PIlipitalioll 11 II WI( Iplllh thnt (limiJlall till PIIOl dill 10 xtralllOlh (0101 (till dptl1minntinll Iph jill 011 tIll dtwlopllIlJIl of H HIli rOI1ll tlllbidity 111 hpl than I (olot rI
jJlIlpOP-ofallnlyi-I ( p(lllil1thb IIllijOI1ll turbidity or 1llt[lIinmiddotd d(ltl of jgtIp(ii(JlI l)~ lIltlkillU tIl plllltollllmiddottri( ntdillU al tandinu tiJlH~ (dlllilll wlli(h IhlllH(lill-- IP 1llutinmiddotly tnhll) t1ll1t an hlsl~1 oil the (oJlItlIlllItion of IIlhlHI Ill I(ill (lIPIipitat((L
TIll -I(p ill till jll()(Plhul HIP 1-- follOylt (1) 1l~UIIL uJ1lplls of thwl UJfJlllHl (II tliddl(l HUt dlipd 11Illtplial an lXIllltel with11 Ill of till nlnll ill t (oU tlllltIPlll[gtPImiddotatlup oil Iath at 11 Cbull fol 11 minutl I) iIP1lIin(middot(lohd til( (XUtllhllll Jltldl lip to It middotml ynlmlll til( (nlifild by (Illlifllgiuu HlId thlPl IlI nliql1ot of tIl (IalioPlllxUlltl nll Uillltlmiddotll(t to l-llll OIlIIlIllril fiuk- (1) For a trial Ilnditlg 0111 III tlll j liJmiddot~t IllHII IIjI to Ohlllll with lilt Pll shy(ilitnnl a 1(11 it 111 (Dod fill llli lIut ( ptotoJIIltlil IPtlllillg-- of pllllntnl or liuht tlUtllIlillal(I oil n (lpel OphotnJlllllI at rase hng-tlt (If 11 llJ Ill Ol It lollllil1lPtImiddott lloyidld with tIll P10]11 I 1110110shy
Ihlolllltt hmiddot Ii1llI Olllhi lIatioll for -1IpItillg UJlproXilll1l tply Wtl P ]Plwth )0 mp are HHlltk TIll Illldillg lliJtaillld fol tIlt 4-milutl tliall(~ll-
bull
bull
bull
RAPID PHOTO~IETRIC DETERIINATIOX OF R(BBER AXD RESINS 37
ing are referred to a table of equhmiddottllut~ previously p1(pa1elt1 on the
bull basis of 4-minute reac1inJ~ for tilE nmge of lot1telltlatiol1- of rubber or resins to bE elHOlll1t(led tmd gidn thtmiddot -tnnlillfr tillIP fill rUbbEt or resins aiter prE(ipitlltiol1 lwfolE photoIllNliI j(tltlill1 un IUade The r(middotnmining dllplllatt aliquot lll then HHllil up te ol1l1Jle and lpoundadillg ale marle ut the -tandillfr tiUlE iudklltll ill rhl tall1lmiddot for the final r(adillg~ -1) 111( milli1lnm or p(tCPlltllt- of lllhbpL (II 1(-in pr(s(nt are rpadholU a prlpan(l table of lquiltlput for tlll photoshymetric readings h1~l(l ill pnell e1-E on pxpPlilmlItal lhln 1111(1 u-ing as stimtlltlds pure luhbll in 1l1bbtl milllYb aIHI guaYllh ll-ill- lxIHlatt~ in resins detNIl1111lttion I
LlTERATlRE CLTED
(1) lUnSbull 1fl36 THE mURMIXTIOS IIF IOTA RE I III OOl THER llT~II
F1 bullrol IlY U(T1l0fll UfSlfi ~rrnrl r flm lt1 KEYS TI Bill Chern 114 44J-l59 illns
t1 ~ICPHHlObullbull T 1J3bull~ lUTHOO roa THE PtRInCAnu Or a(lIUl IRrIlHU It of TIn
PLRIHEU Htllllflt [ i Bill lallllall 111 Rmiddot 711middotj iIlus
I ) RHBERG P B Ul5 A METHIlO Or ~u(ronrll-nl Hi tIII rUIl[1 f71 ii illlI
bull 14 Hoss W flbull and HARDESTY J O
llH IR1ltDII Of HfITilIZfmiddotR DllIJS ltt 1 Yl fll Off gI bern JIIIlI i ~middotmiddotlf IIl
101 SPEltCE D nnd CuoWELr ~I L 1933 DETER~n-ATIOo OF RtBBER Ii nrllllpoundRBfR Iusr 1uI II1 amI
Em~ifl cttIliIa~~ r Ell i 71middot7i l11 (HI WALTER E D
1U44 ISO~nlS OF PRTlltSrr 1trHpoundV bull l UI n W lHHt (Tnmiddot 1ETS FROM GiYI l~iIl lItr Clttrn SII J UI titJ middotn9--C1 ilIu
17 J YOEbullbullr H lO~( roLORIlETRT 771 IPmiddot nl -W Yurk f H Plrwptric hmica
naly-II rimttry lUll XphHHlnmiddot~ y 1 1
11
HI) ~ fPHELolzTRf 57 111bull Lin xw Yk t H lt PhmeHt CblUlmiddot ila AnaiY~l~-(H lithrry and XIhmiddotILpfIY Y wirh enomiddot rrJlllrjr hy H KtlJnJU11 I
t~1I --- and ~ARVER L 1f41 nlua-w ~in L liLhr IS IP ll~ XIW Yrk
bull For-sale by th~ ~a~fr1nt~nf1ent Dt~c~~ogtnts-~ s t1i rArnn~ut Pn~~~ tJffieshy
Washington 5 D C bull Pl lU ~nts
bull
bull
bull
RAPID PHOTOMETRIC DETERMINATION OF HUBBIm AND HESINS 29
The resins standard selected is based on n relatively pure source of resins the rcsinous exudnte 011 the stems of guuyule plants IJldimishynary expeliments with the resi nouS cxuclate from diffcrellt gllayu Ie strains of various ages indicatc nHlt there is little YaLiation in this subshystance on the basis of Colorimct(r readings 011 2-mg aliqllots of 01shypercent solution in It 2i-ml volume (tabl( li) Expelilll(lnts have shown that the air-dried (xuclate contains 3RtOH p(Ic(nt of -volatile matter This material is l(latiyt~ly stablp ill (OlllpoBition and is npshypurpntly on ly slight ly hygroBcopic as shoWIl ill Ia bl(1 1 Tlrp Ipsinolls exudate may be jJleplpd in two wayi-i fl liSP as a stallClHld-(l) the clpan exudate is clripd iol Ghouls at ()1deg C at W indlPs of a(lIum Hnd aftclbCinOglOund ill a molfalis 1)I(spI((I intn airtight COllilinel OL
(2) tllP Cx7lclate is clissolllt1 ill a(lhllll and filtplpd PlactieaJlyall of the acetm1l is thpn lYapolntwl olt OPI a stlam or atCt hath and Ow residue is dripd ground an(( PI(sPIld as ill tllp fin lllethocl Tlwse two prepalHtlolls a1( (ompalpd in ta hlp ) 111( (((tails fOl ~t()lil1g the resins standald and (onstlllcting the calibration CUITPS alc given Oil page ]2
lAIIIg fi-CUIIIllrsoi (lJ lIr-dr(1I IIIIi 1((11 II II-()I-tr((l l(sil~ 11111111(8 of I II 1111Ie
[Colorimetric rrndill~s 011 1~I11 phulll(Iclrie eolorillJct[lr with i~()middotmll (100- to iiOIIIIl) fillcr [lnd 5-1111 lIperture preeipitantl part ofO5middotPIrctllt 10 to 5 paris of IIOj
nupliclllc(oloritwt([
nIl(lin~s (hIlSlcAg~ ofSlmillXo JrNliltlCllt of fPsiJI$ L1Xtlrlntp on 2 IIIg ofplanls fllsins (XIHIIlt~Jwr 25-1111 vol
tII1(1) 1
leflTs Various _ bull ____ bullbullbullbull 3-9 Colll)Josiltrlairmiddotltlricfl bullbullbull nf)2 002
])0____ bullbullbull _bull __ _ bullbull ~-l Composilld (ri d at n5 C in aUmiddotimh lWUUllJ for l (jOuj(ja hours])0______ bullbullbull __ bull ___ bull 3-0 COJIlpositld disso]NI in neptolll f1l1erNl fl(lf()ll( GGO i(jO (Ivaporntld olT OV(1r Stpl1l11 halh TesidlH drl(ld I1t fi5deg ( ill anmiddotinch VIl(Unlll for 0 houlS bull
middot106 __ bullbull _ Jir~c1rild_~_~_ _~_ ~_~ _ ~ ____ _ __ _ OUu GOifina_~ ~ _ ~~_~ ___ _ _fln~ ~~ ~ ___ ~ __ 6(imiddotI tiliA H)[_ ltlu bullbull i18 tisSflOabullbullbullbull__ bullbullbullbullbullbullbullbull lt10bullbullbull _ tillO llitO406__ bullbull __ bullbull __ bull __ __ lt10_ Utl2 fon591_ fo__ bull liGa oOa 406bullbull _ __ lt10bullbullbull_ li5S OM
j Ph( vnluls in Uw Inst COIUIIlIl indieatp thnt gunyulp fesinous (IIHlnt( wlwtlwr dfircl hi Yn(tlLJ1l1 wilh L~ perc(nt loss of volntllt wutl pr or tWl c1rild giVPd npproxil1lnh1ly t Iw snllw colorinwtCr rNHiing- 011 till busis of aliquot~ cOlllniuiug 2 IJI~ of flsillS lXIHlntp l)tIf 25-mI volultl( Ihil- illdicate~ thl11 Uw UITW IJ1flS~ of olnshytile mntl(f prt~(iJlitnt(d gins npproxilllntlly Uw $1II1l (oiOfirnl1tlf ftudiTlJs ns tho ftsidtw A pnlill1jllaf~middot (XIlltrinllnt indicutls thlli th VUllltill muller l(lIlSists of thl Ilrplne oil fmcl ion I5-(1Il gtnplls or rlsitlOtlS (lxudntll gnvll by stPll1U distillation nn Uefllgl of 011111 of jl(lfPlIW oil with npproximHte tilllsity (If OHIi lind lhus rrprlsll1ll( IlPIJroximllt(I~ 01 Jerccllt Of t he original weight 1hls lllrClnlage complrcs wllh 38 llltrC(ntlost by drvinI( in IICllnllJ
aSplusmnUH perceilt or orlginlll weightlosl
The wailnble illfolJllntioll on tlH (ow-JitlPllts of the gunYllle r(~shyillOllS exudate alld tl1( HeetOlIP ext act of gaylp ti~slw is sllIllmarized in this paragraph lYalttI (u) alld also Hangcn-Slllit lind his coworkshyers 16 reported that 20 percent of the resinolls exudate from gUltyulc stems is parthenyl cinnamaie (CHuOH=CHC020 11JI2r) Steam disshy
15 (OIlIJIIIIUicatioll flom A T Haai(II~l11it llId (0011(11 Calif0111 ill Tnfiitnte of Tccllllology Past(IlIJI Jhps( wOlken al Htud~ing the COTlHlitlllllts of the acetone extract and other conlltituellis of guuyule
30 TECHNICAL BULLETIN 920 U S DEPT OF AGRICULTURE
tillation of similar resinous exudate in the writers laborntory has yielded approximately 4 percent of the whole as the telmiddotpene oir fracshytion Haagen-Smit and his eoorktrs nportec1 thttt about 25 percent of the acetone extract from guayule branches is parthenyl cinnamate and 6 percent of the bark (ltortpamp-phlotm) extraet is parthenyl cinshynamate These workers fm-thcI reported that 25 lwletnt of the nc(shytone extract frolll bLllllches is a compound with the tlI1pilicaL formula CBoH400a 1 percent is a compound llwltillg at 2P to 2T5deg C and 1 percent of the extract from the ]eav(s is tl (olllpoulld nwlting at 100
to 1710 1Valtei (6) reported that 3 to -l perc(nt of the tI(eton( txtract
of leaves and flowering StPIllS of guayulc eonsists of waxlike substances soluble in olgallic soln~nts but insoluble in at(l and (on(ent1llted H 2S04 The flactions mentioned on the basis of (onHLTutle esti shymates of amoullts actually isolated tlecoullted for about H ptIcent of the totalncetollt~ so]ubles extracttd from tll( guuYllle 11 rub The other constituents ltlilaill to be i(](ntifi(d
RUBBER AND RESINS CALIBHATION CVHES
Typical culibndioll Clllves iol Iuhbpl and I(sins bas(d 011 (ldtLminttshytions made nccoLdillg to the plocCdmC outlin(d 011 pages middotb to 1G arc shown in figulPS 5 and 1+ The spCdlopliotoll1lttL en (OIOIjlllctCI readings are plottCd on s(lIlilogalitllllliC pappi ag-ail1st (Il 11IbblI (011shy
100 ~ 90
80 ~ 70 ~
z 1amp1 0 II 1amp1 IL
1amp1 0 Z
60
50
40 ~ltI 30 ~ en z ~ ltI II ~ 20 C) ~ oJ
10 o 2 3 4 5 6 7 8 9 10
RU8BER IN 25-ML VOLUME (MG)
bull
bull
bull FI(lURE 14--Ctlihration curve fotmiddot gllftYlIlc lubb01 (Hct(lings Oil COIPIIHlII tlOl1hl(
monochromator SlCClrophotolllet(r with 7fiO-11IL Illtel alld Hllp Wll ( IHlll()
bull
bull
bull
RAPID PHOTOMETRIC DETE~MINATION OF RUBBER AND RESINS 3]
centrations From a casual inspection of these CUlTes it would appeltr that Beers law does not hold Actual tests indicitted that Beers law was applicable only within a narrow range in the upper portion of the curves The analyticlil results on the basis of photornetric readings nre therefore calculated by direct reference to calibration curves or from reference tables of equivalent values bllscd on the cnlibllltion curves
Calibration curves for kok-saghyz alld heyea lI11tulltl rubbers and Buna S (GR-S Chem Gum IV Goodyear) and butyl (GR-I Standshyard Oil Co Protoc) sYJlthetic rubbers are hOWllil1 figure 15 The samples of kok-saghyz rubber were furnished by the Diyision of Rubshy
100
90 ~I) ()
z 0
1amp1 a
~ a
80
70
60
s 1amp1 ~ ~ 0 ~ KOj-SAGHYZ 0 l Il
50
HEVEA~ ~
40
100
90
~ 0 80z Q 70a Co)
a 60 ~ 0 0 x 50Il
40 ~----~~----~------~------~------~--~ o 2 3 4 5
RUBBER IN 25-ML VOLUME(MG)
FmUIlE 15-CaJiblation curves fOl kok-snghyz h(YCII Bunn S lind butyl rubb~ls (Readings on gy((yn photoelectric colorimeter with i20-lIIp filtpl and 6-ml aperture)
32 TECHNICAl BUIJLETIN [)20) 1 S DEP1 OF AGrnCUIlfURE
Iwt Plant JIl(I~t ignlioll of thi BlII(un and (1( l))(parcd according to 11( SPltI1((-Culd (]] (6) PIO(((lllll Hlpt pal( CLPPe was (xtmch(L with acetone blI()Ieit W 1I(gt(11l a ttnlldal(l
SEXSlllVllY Ol~ llETJIonS
By lip pIO((l(II11P olltlillP(l 011 ]Hlg( +n Iowa (lOOl IIIg (11 1111i(l0shygmm (gHlllllla) of 1hblI ill a 2)1111 yoltll1ll (all )(gt dltpltld Oil tltl Col(man (lohlP mOIlWhlOl1lHlOl l-I)((t 101 l1lOt 0111 ci( I ill1ilnlly 001 mg of Iublwr ill a 2J-1ll1 n]ulllP Illay bl Ilad Oil till EnI)1I photoshyllectlie (O]oLillllt(I Thll ya lllll- 011 tilt IHl-i- (J I (xl ad iOI1 fmlll 02 gill of til-lI tH(JI(lillg to tllP -lllndal(l jll()(pdull 1(PIPStlIt IlO()2J tlnd 002) P(IT(lIt of llIbl1ll IPI)(((inly bull1t1lollgh -lI1t low allils can be d((d(middot(1 il lIoullt1 Ill IPtllizpd thnt till PIIOl ill PlI(Plltng( or tll( al110unt dltlIllIilll(J i ltlatlpl high ill tili PIY lo Itlllgl 111 aetllllllladie(middot Ill( lopl lillliL 111)(1(1 lIw (ollllil ions of tlil ]lI()(lltlIIIl u ol1tlinpd ipt at l11 11I1 or 1111gt11(1 illt i-1ll1 Ollllll IlPIPltPlltillg 01 p(gtl(pnt of JllUiJtL un tlll 1Hli or (xlla ion rlOI11 II rlll of tisSIll
EIlIlOH COSIIlIHIIO
In Oldpl to H(IIp ill )1lHtPltt pl((iioll illlpIi1I- it i lH((SSHI to slnlldHIdiz(i rigidly 111( Pl()((dlll( 0 illdi(ntpd Oil pnglt- - to J( If lids i dOlH tlip lXIHlinwnlal PIIll is t(middotdllld 10 n ndninlllill
Illlt pl(iioll of (hI ]lIPPllt 1IHllwd Oil til basi of ]llllP llIllJt1 alld Ipsinssollltions call hI jlldgl(J 110111 figllll Hi lileh lio- til HPIlIgl d(intioll oft -illgIP lI1lnSIlIlIIIlnt in lHi((lltagl of Ill( alllOllllt 01 Illhshy1)() 01 lpsins d((PI1I1 iJlld TIl( (1101 PlI(Plltaglt H1( gi (1 101 OJ) to
RUBBER IN 25-ML VOLUMEMG) 004 01 02 03 04
i= I I IZCtOW
fbA ICtU CtCt WW a
01 02 03 04 05 06 07 08 09 100 = RUBBER (PERCENT)
RUBBER IN 25-ML VOLUME (MG) 10 20 30
~ I CtZ
bBOw Ctu CtCt Ww o I~
010 50 100 150 200 250 RUBBER (PERCENT)
RESINS IN 25-ML VOLUME(MG) 10__ __3-0_ 40 50 60 70 60 90 100--_-- 2_-0
Ct~ -r- 1 I OZ
WCt UCt b C wCtW
a o I I 150 250
RESINS (PERCENT) o 10 50 100 200
bllI 1tI W-Yllnl dtd1 ioll I I 11l1 11IlI11 1(111(11 1 III Plll- IlIIIlol1 01 IIim~
bull
bull
bull solution Il basis J o golH of tiSSII (JlILCl-nt (11(11) for (~I) (l)1 til O 1I1
of luhllpl lin 1 III I (I Ill of lUhlJPl nllll laquo I J to 111 nlg of IlSlllgt (Itllillgs on ]iYllyu pllolwh-llrk CO[IJlilll(-(PI with nOHIP Iiltlr lIntl U-lIll allcrture)
RAPID PHOTOlJElRIC DELEHlllNAllON Cn HUBBER AND H1~SINS 33
10 mg of rubber anel1 to 10 mg of resins in a gJ-m1 yolumC For
bull
bull
bull
comparative ptuposes the leslllts arc also calculated on the basis oJvershycentage rubber OL tltsills in 02 gllI of tissul As WOlllL be expcet(d the error increases sOIlHgthlf for 1(lali nmiddotly low COlHell t1llf iOlls oj rllbbeL or resins The curves in figure 1(j s1l0 that ill til(gt Illlge Ol to 10 pCrshyeent of lubber the elTOI rangts Jroll1 abollt Ll to II) ]IlC(lIt abo(~ this mlllc tIlt (ITOl d(((ts(s to (ollsidlItbly ltmiddotss (han 1 1lICPllt of tlH mllollnt ltl((Lmill(d Hil1lilally in tlH (lISl of l(sins analysis (fig 10) the ltLTor is (onsit1eIubly INS than 1 PlLllnt ill (he lallgp of 11 t~) ~() penPII t
In nil ([lSl of lllhblI alld (sins lx(Inltpd tIOIl1 (issups Ol addcltl to tisslle lxtlads (s(( tabhmiddots (i H) illyolillg ll01P o(lllntiolls the eLI01
is hig]wl thun that indilHtld in figllll ((j Im pUIl Ill )])p I tllllllsins solutlOII
COlllUCIIOXFOH IXSOLl-IlLl~ Ilgsqgt(Jg
111 th( Jllo(pdulP ollllillPd 011 paw I till illsolllhll isSII Ipidll( tflpl (xttlw(ioll is (Ptill tlw lIask l(lll till xtlct i l1wdp up to yoltlllH It is not rOllPllipnt (0 IPt()PI qWlIltitati(Ir III(lw[olH a 11(1 pllooll extlnlfs of guuyull I is-lll alll thl1l main t11l111 up (0 YOIUllllmiddot bpCaUHI sllch all additiollal stltp wottld]) tillll-C(JllS11ll1illg Th( Iogiea nll(gtIshynntin is to mnkp tltl lXtlUCt Llld Ipsidup lip to OllillH in till original flask andi llPSStllY 10 llwlno tl OIIpdioll wlHIl (allIlnting [hc llshy
Hults f(JI [hl oll111lC displupd hy till ins()lllbh llsidll( III it l)picat (IXpednHllt (ollsisting of Jhp lppJiea(iolls if was Iollnd llftt at ~iiO ( 02 gill 01 Iuhhll pillS IPill-fl(( lisslI(gt (lollpdll fot llwistUlC ou basis of dlyillp ut lOW 101 ) llOlll-j (lbp(ld only t~ llllUll voiul11P of OOk7D~- OO(lOO(i Ill of lllthyl bolnl(yl 1lIOll( (lplhlli(al-t(Tnltle sp gl () Ii I ll(Hli (j at ~)) -gtitllP tl1(gt 1It101111( () r t is-lIl xt Iadld j sl1lall til( PlIOI dul to Ill(gt insoll1blp Ip~idll is slllall III [0111 ill( wOtk it (all lJp diIpgal(ll(l
]hcon~lIY OF HllIllgl AiO HESIS AIH)gl) TO EXTlIACI OP
GlYlLE TISSlg
Tnl)ll G L(IHpslntillp (ypi(nl llld(~ SllOS (hat all a plngl of HIOK PlI((nt ot lltl pltl( Ilhl)(l acldpd to tllP Itll h iolJut1 InmiddottcJllP xhnet
of guayulp tiSI1( WllS 1l((PllIl Tlli nllintioll flOlll (olllplpU I((OYshy
PIY i within flll pxp(IiIlHuttllIIOI ~illli]llly fnbll Ii llows thn 1111 llYlIUgl of 1O(1~ ])(I(Pllt of gllllYllII 1(-i1l- add(d to II( (pllosol( (xshytrae of IUllY]l t i~HI Is 1l(oPIPI
THl~ (~ Hf (Off Ill of 1111)( J OJ I~il~ lItfI(( In ~(JI1IJk~ Ilf (111 [lI1Il fI2 lIII
0 tlUfllllit i~~I1
Instrument
---- ----~---- bull shy 1(1
Colemun ruono~ltrOUlllt()r 2t) II sJl~ctroJlhOL()lIIeter with 2tJ I iflllllI wnclength Fetting 21 II nntl 0-1111 WU HI hUJl(L _ L U
Ill 7Evolyn photo~lcclrie (olor JU [ imctcr with iO-llIl filler IV (I
H1 0 t I I
llImiddot lUn WII 1011 HIO Wn mil lUulon
10 JIg1111 IUI ml lUl anh Io aLn 111)_I ) III li lU It 2) deg wn2SU DD
Irl JIll II IIr II US II
1110(1 lULa lUI IlK) IJ WU
I( llI Htl tNI 1(111 2tlNI HI 0 221) lllil t2S 0 1~ 10 1~13
In (I 2117 I
10U 1l(J ~ 4 _H_j ___
9middotJIlJ5 10115 10 00 lUU5 flUU 4li (tl03 9(11)
leIlKl 1l~)5 lOOU l1KIr JOIS un 003 OIl Ii
34 lECHNlCAL BULLErIN 920 U S DEPT OF AGRICULlURE
COMPARISON OF PHOTOMETRIC A1D MODJIoIED SPENCE-CALDWfLL METHODS OF RUBBER ANALYSIS
Guayule samples were analyzed by the photQ111etIic method and by bull the modified Spenc(gt-Cnldwell mcthod The values in table 7 represhyselltativ(I of typical results indieate It -atisfactory dcglpe of conformshyjty between the two methods in thl range of tiSSlHH with llHHC than OJ) percent of rubbtImiddot On the bnsis of the amounts determimd the results in this runge for the plmiddotts(nt lIlcthod ayernge apploxinHltely j percent highcr
~LAIII~ 7-(oIllJl(i~on of lltlllrIic (IIri mOtllinl SJl(II(r-(ulri-wall IIIrtlwrl~ of rlrrlIIillillfl 11)1)(1 COIIrll of UI(III
1 Flowers frllm amiddotmonth-oltl nursery plants
YAIIIATJO- OF SIli(LE DETEnt1NATIONS Fnoll TnEIIllIEAN
Rllbbel (Uall8i8-Thc plcCision of thc pLcsent method when gunyule tissues Hr( nnnlyz((1 for rubber may be j udg(d flom I Ill datil presentcd in table H TIl(se dahl -how that thl pplCPlltag( uriation of single determinatiom from nwan yullles with low standllrd enolS ranges from less than 1 to 4 p(gtrlent
R(8in~ wWlsi-r-s lndi(a((1 011 page ~j he INntlts s((uled hy the present phoolllttric nsins llHt hod are not tliltly (olllpalable with those of the grtLVimetri( ncetol1l-cxtlt1(tioll II1etho(l Thjs made it necesSllry to selc(t another lalibllltion staudud-tlll Ipsinous exullate from gullyule shrub-thut gies relatively COllstlllt photometric readshyings (table 5) The resin (olltents of guayule roots branchcs or leavcs usually ran(~e from about) to 1-1middot pelcellt The ple(ision of the present methotf WhCll gUHyule thslllS lIe analyzed for reins may be judged from the datalHmiddotpscllted ill table 9 1h(se data show that the p(lcelltage variatiun of sillgle lhmiddott(Lminntions iLO11 meun ynlnes with low standard NTOrs rangcs from about 05 to 4 percent
bull
bull
bull
bull
bull
RAPID PHOTOMETHIC DElEruIINAlION OJ RUBBEH AND HESINS 35
IAIILE 8-luriation inclieute rubller (mallSM of [1wIIle tissue bll thc 1111O0Illclc metwII
Vnrlntlon~Ilbher I (rom mean
ierCtnl Percelll ~OU -22 ~ 25 +27 ~ 20 +18 ~UO -22---------1_______ 51110 0G6 bullbullbullbullbullbull _bullbull
10 ro ----=ii41075 -01 1000 +11 1010 +13
rlln HI itil 1l9~ 1_ ___ =-~~~
115511 ~ US -111 III II 1575 -13 115 b tiS -I a 111 h WlU +22IIM-(middot bull 11K -1Ja Illi c 1000 +03 1J5H1 W +l)7 ll1imiddot tl 1575 -13
Mcnn 15951 131
1102-11 21fJ() +21l102-h _ ~~)SO -17 1102-c bullbull 21CO +21n02middotd ~OIiO -26
2 r~plusmn Il~ 21151 261 I -~-------bull---__ _~~_~______l-___--_
1 lhe$ 1111($ I1n (or SlIlIIllltS Stpnnltplr PHrilClld IIrtlrdlng 10 1hr prollIlIlr( OIiIIiIl(o(I on Imgt$ 4 to IC ~tcond nUlI1 hlr r(J)[ltnts stl1ndnnl llrrot of tilt 1I1(1111
1_1l1~ n-J(lri(iot in relli(Upound rpoundsins (lllalIsfs of VIOJII( lixsue b1 the lhomillric lII(lloli
-- ---~--- - __-------- shybull I I I I Varlgttton
_________~___ ~~lu_n_Jl_Q_~~~_____ ______I__~_o~S_J frOID lDean
Percent Percentgt458-1 ~65 +41IWtl-li 130 -a2Hli8c aliO +26S41i8-d bull 130 -32
1(-011 34I10Olifgt __ bullbull __ ~--====
li-9~2n 881) -06 li-9~2-b Si5 o ~HH2middot(middot S i5 -6$-H2middotd 000 +1
8851 054
O i5 +6 9 i5 +6 950 -20 U75 +6
H-liG3o-n bull -1 n-li6~b bull __ _ -IH-IWH +4H-l61511 bull -1
1tmiddottlU
62~-lI __ 62~-b ij24-( bull OH-Ji
(-Ull
I rll(St oluls nre tor separately ~xlrflCled SllllllllCS IlctOrdlug lO procedure outllned ou pages 4 to 10 i Secoud number r~prtgeulS stulldMd error of lIe menn
36 TECHNICAL BULLETIN 920 t ~ DEPT OF A(]RICCLTCRE
ReUUER A~ALYSrS I~ CRCOE-RcuUER PROOCCTS
Sew rapid photometric m(lthod~fol the ddellllinttion of rubber and reii Hi ill uaYllp ti--ut htp lllell pIPHnl pd oil pag( ~l to In A brief H1111111tlY of It similar rnpid llHthod fm 1I1hb~rllnltlysis of u1lulcanizNl tlIldp lubbll pl(Hlmtlt whielt i~ bn-(tldo on the prill o
ciples dehtilcd tlllLe follows Duplltate nt-gm sllmph of the finely cliyiliNl IlInttlitiup wlirllll out [~ei-()l (all hl lIf((tinmiddotjv INd to lt1iyidl till alllpl) TIll kltolll-olubll portion of till )111(11( tlrc di-olved a- indh-Htpd fot thmiddot lllnkill~ of -tlllHlunlluhhll olutiou Oil Pt 1II hut tIl IUlIp Hn lIn l-fplImiddotd 10 lHI-ml rolllllltti( fln-k antil1ltld(lup to Olllll1l The bnlulUp or till JllO(ldllll i- thatutlilllll on paWs -1- 1 IHI Ii 111( 1(111 1- nIP IXPIP--pd nil til IHi or Iw oligiJla w(lullt of I Ill (I11l1p-I1l11Ilt1 1)(0(11(1
Hupitl PlllimiPJojgtiWllllllllh llIltllOd~ fOJ Ihl llPtlmiddotminntion of ImiddotUlJbll tlnd 1(-illo- ill -111111 Illllph of gutlYllll tiUl IIll dl-eli)ed 111() IlltlY d~o Ill nltlI1lld fOl III Iwl Illhlwl- and l~iJlmiddotb(lLiJlg plant TIllt l[Olllhup hns nlo b(l1l ntuptpl fot IIH lltlIll1illtltioll of lllhbpl ill 11lHhrublwl Pl(Jdlld~ HIIl 1111 hI ndaptld JoJ IIll ann lysis of ynt1J(gt( ic lllbbl[- The llllthmb HIP 1gtn(11 fill tIll fol1owill plimiph- III Grinding
tIll PIOPlly driPl t i~lIl 01 Ul tillg tIll pnHhHt to tll l((lllilllllh~lel of filWlH-- til plllllit qIHlIllilnth( lXIIHtioll 01 IIlbhlI 01 1(--IJl- () llsing oXWllutld olnuh (kttoJls IIt(talp and() fllltil for LIbbel and IH(ltIlIlyptIJllIllIoolYlnJld-o flJllh 101 niJlsl with t(lathelr high IlPililig points 111 to n C) l]olle or in mixt tIll thllt Pll mit tlll rnphllxututioll of luhll(l OJ [middot(ill ill ~() to (l mi1lutp It r(latiwly high 1lllIllllltlltP Ill to 1~11 ) l) lllllipitntillu till luhblI OL Imiddot(ill frolll aliquot () f till oltn ion I IlIlllI-i () f Hlltabhmiddot pl(~(i]litallt (willifhmiddotd lthmwl fOl IIlhlHI Hild llitlifild lllr fOJ JP-illl t~) IIlHkillphotollllliilPIIIIiIlof PlllPlltal of liht tLaIlS mittUl(P lIftlI IlIlbll (II Il in PIlipitalioll 11 II WI( Iplllh thnt (limiJlall till PIIOl dill 10 xtralllOlh (0101 (till dptl1minntinll Iph jill 011 tIll dtwlopllIlJIl of H HIli rOI1ll tlllbidity 111 hpl than I (olot rI
jJlIlpOP-ofallnlyi-I ( p(lllil1thb IIllijOI1ll turbidity or 1llt[lIinmiddotd d(ltl of jgtIp(ii(JlI l)~ lIltlkillU tIl plllltollllmiddottri( ntdillU al tandinu tiJlH~ (dlllilll wlli(h IhlllH(lill-- IP 1llutinmiddotly tnhll) t1ll1t an hlsl~1 oil the (oJlItlIlllItion of IIlhlHI Ill I(ill (lIPIipitat((L
TIll -I(p ill till jll()(Plhul HIP 1-- follOylt (1) 1l~UIIL uJ1lplls of thwl UJfJlllHl (II tliddl(l HUt dlipd 11Illtplial an lXIllltel with11 Ill of till nlnll ill t (oU tlllltIPlll[gtPImiddotatlup oil Iath at 11 Cbull fol 11 minutl I) iIP1lIin(middot(lohd til( (XUtllhllll Jltldl lip to It middotml ynlmlll til( (nlifild by (Illlifllgiuu HlId thlPl IlI nliql1ot of tIl (IalioPlllxUlltl nll Uillltlmiddotll(t to l-llll OIlIIlIllril fiuk- (1) For a trial Ilnditlg 0111 III tlll j liJmiddot~t IllHII IIjI to Ohlllll with lilt Pll shy(ilitnnl a 1(11 it 111 (Dod fill llli lIut ( ptotoJIIltlil IPtlllillg-- of pllllntnl or liuht tlUtllIlillal(I oil n (lpel OphotnJlllllI at rase hng-tlt (If 11 llJ Ill Ol It lollllil1lPtImiddott lloyidld with tIll P10]11 I 1110110shy
Ihlolllltt hmiddot Ii1llI Olllhi lIatioll for -1IpItillg UJlproXilll1l tply Wtl P ]Plwth )0 mp are HHlltk TIll Illldillg lliJtaillld fol tIlt 4-milutl tliall(~ll-
bull
bull
bull
RAPID PHOTO~IETRIC DETERIINATIOX OF R(BBER AXD RESINS 37
ing are referred to a table of equhmiddottllut~ previously p1(pa1elt1 on the
bull basis of 4-minute reac1inJ~ for tilE nmge of lot1telltlatiol1- of rubber or resins to bE elHOlll1t(led tmd gidn thtmiddot -tnnlillfr tillIP fill rUbbEt or resins aiter prE(ipitlltiol1 lwfolE photoIllNliI j(tltlill1 un IUade The r(middotnmining dllplllatt aliquot lll then HHllil up te ol1l1Jle and lpoundadillg ale marle ut the -tandillfr tiUlE iudklltll ill rhl tall1lmiddot for the final r(adillg~ -1) 111( milli1lnm or p(tCPlltllt- of lllhbpL (II 1(-in pr(s(nt are rpadholU a prlpan(l table of lquiltlput for tlll photoshymetric readings h1~l(l ill pnell e1-E on pxpPlilmlItal lhln 1111(1 u-ing as stimtlltlds pure luhbll in 1l1bbtl milllYb aIHI guaYllh ll-ill- lxIHlatt~ in resins detNIl1111lttion I
LlTERATlRE CLTED
(1) lUnSbull 1fl36 THE mURMIXTIOS IIF IOTA RE I III OOl THER llT~II
F1 bullrol IlY U(T1l0fll UfSlfi ~rrnrl r flm lt1 KEYS TI Bill Chern 114 44J-l59 illns
t1 ~ICPHHlObullbull T 1J3bull~ lUTHOO roa THE PtRInCAnu Or a(lIUl IRrIlHU It of TIn
PLRIHEU Htllllflt [ i Bill lallllall 111 Rmiddot 711middotj iIlus
I ) RHBERG P B Ul5 A METHIlO Or ~u(ronrll-nl Hi tIII rUIl[1 f71 ii illlI
bull 14 Hoss W flbull and HARDESTY J O
llH IR1ltDII Of HfITilIZfmiddotR DllIJS ltt 1 Yl fll Off gI bern JIIIlI i ~middotmiddotlf IIl
101 SPEltCE D nnd CuoWELr ~I L 1933 DETER~n-ATIOo OF RtBBER Ii nrllllpoundRBfR Iusr 1uI II1 amI
Em~ifl cttIliIa~~ r Ell i 71middot7i l11 (HI WALTER E D
1U44 ISO~nlS OF PRTlltSrr 1trHpoundV bull l UI n W lHHt (Tnmiddot 1ETS FROM GiYI l~iIl lItr Clttrn SII J UI titJ middotn9--C1 ilIu
17 J YOEbullbullr H lO~( roLORIlETRT 771 IPmiddot nl -W Yurk f H Plrwptric hmica
naly-II rimttry lUll XphHHlnmiddot~ y 1 1
11
HI) ~ fPHELolzTRf 57 111bull Lin xw Yk t H lt PhmeHt CblUlmiddot ila AnaiY~l~-(H lithrry and XIhmiddotILpfIY Y wirh enomiddot rrJlllrjr hy H KtlJnJU11 I
t~1I --- and ~ARVER L 1f41 nlua-w ~in L liLhr IS IP ll~ XIW Yrk
bull For-sale by th~ ~a~fr1nt~nf1ent Dt~c~~ogtnts-~ s t1i rArnn~ut Pn~~~ tJffieshy
Washington 5 D C bull Pl lU ~nts
30 TECHNICAL BULLETIN 920 U S DEPT OF AGRICULTURE
tillation of similar resinous exudate in the writers laborntory has yielded approximately 4 percent of the whole as the telmiddotpene oir fracshytion Haagen-Smit and his eoorktrs nportec1 thttt about 25 percent of the acetone extract from guayule branches is parthenyl cinnamate and 6 percent of the bark (ltortpamp-phlotm) extraet is parthenyl cinshynamate These workers fm-thcI reported that 25 lwletnt of the nc(shytone extract frolll bLllllches is a compound with the tlI1pilicaL formula CBoH400a 1 percent is a compound llwltillg at 2P to 2T5deg C and 1 percent of the extract from the ]eav(s is tl (olllpoulld nwlting at 100
to 1710 1Valtei (6) reported that 3 to -l perc(nt of the tI(eton( txtract
of leaves and flowering StPIllS of guayulc eonsists of waxlike substances soluble in olgallic soln~nts but insoluble in at(l and (on(ent1llted H 2S04 The flactions mentioned on the basis of (onHLTutle esti shymates of amoullts actually isolated tlecoullted for about H ptIcent of the totalncetollt~ so]ubles extracttd from tll( guuYllle 11 rub The other constituents ltlilaill to be i(](ntifi(d
RUBBER AND RESINS CALIBHATION CVHES
Typical culibndioll Clllves iol Iuhbpl and I(sins bas(d 011 (ldtLminttshytions made nccoLdillg to the plocCdmC outlin(d 011 pages middotb to 1G arc shown in figulPS 5 and 1+ The spCdlopliotoll1lttL en (OIOIjlllctCI readings are plottCd on s(lIlilogalitllllliC pappi ag-ail1st (Il 11IbblI (011shy
100 ~ 90
80 ~ 70 ~
z 1amp1 0 II 1amp1 IL
1amp1 0 Z
60
50
40 ~ltI 30 ~ en z ~ ltI II ~ 20 C) ~ oJ
10 o 2 3 4 5 6 7 8 9 10
RU8BER IN 25-ML VOLUME (MG)
bull
bull
bull FI(lURE 14--Ctlihration curve fotmiddot gllftYlIlc lubb01 (Hct(lings Oil COIPIIHlII tlOl1hl(
monochromator SlCClrophotolllet(r with 7fiO-11IL Illtel alld Hllp Wll ( IHlll()
bull
bull
bull
RAPID PHOTOMETRIC DETE~MINATION OF RUBBER AND RESINS 3]
centrations From a casual inspection of these CUlTes it would appeltr that Beers law does not hold Actual tests indicitted that Beers law was applicable only within a narrow range in the upper portion of the curves The analyticlil results on the basis of photornetric readings nre therefore calculated by direct reference to calibration curves or from reference tables of equivalent values bllscd on the cnlibllltion curves
Calibration curves for kok-saghyz alld heyea lI11tulltl rubbers and Buna S (GR-S Chem Gum IV Goodyear) and butyl (GR-I Standshyard Oil Co Protoc) sYJlthetic rubbers are hOWllil1 figure 15 The samples of kok-saghyz rubber were furnished by the Diyision of Rubshy
100
90 ~I) ()
z 0
1amp1 a
~ a
80
70
60
s 1amp1 ~ ~ 0 ~ KOj-SAGHYZ 0 l Il
50
HEVEA~ ~
40
100
90
~ 0 80z Q 70a Co)
a 60 ~ 0 0 x 50Il
40 ~----~~----~------~------~------~--~ o 2 3 4 5
RUBBER IN 25-ML VOLUME(MG)
FmUIlE 15-CaJiblation curves fOl kok-snghyz h(YCII Bunn S lind butyl rubb~ls (Readings on gy((yn photoelectric colorimeter with i20-lIIp filtpl and 6-ml aperture)
32 TECHNICAl BUIJLETIN [)20) 1 S DEP1 OF AGrnCUIlfURE
Iwt Plant JIl(I~t ignlioll of thi BlII(un and (1( l))(parcd according to 11( SPltI1((-Culd (]] (6) PIO(((lllll Hlpt pal( CLPPe was (xtmch(L with acetone blI()Ieit W 1I(gt(11l a ttnlldal(l
SEXSlllVllY Ol~ llETJIonS
By lip pIO((l(II11P olltlillP(l 011 ]Hlg( +n Iowa (lOOl IIIg (11 1111i(l0shygmm (gHlllllla) of 1hblI ill a 2)1111 yoltll1ll (all )(gt dltpltld Oil tltl Col(man (lohlP mOIlWhlOl1lHlOl l-I)((t 101 l1lOt 0111 ci( I ill1ilnlly 001 mg of Iublwr ill a 2J-1ll1 n]ulllP Illay bl Ilad Oil till EnI)1I photoshyllectlie (O]oLillllt(I Thll ya lllll- 011 tilt IHl-i- (J I (xl ad iOI1 fmlll 02 gill of til-lI tH(JI(lillg to tllP -lllndal(l jll()(pdull 1(PIPStlIt IlO()2J tlnd 002) P(IT(lIt of llIbl1ll IPI)(((inly bull1t1lollgh -lI1t low allils can be d((d(middot(1 il lIoullt1 Ill IPtllizpd thnt till PIIOl ill PlI(Plltng( or tll( al110unt dltlIllIilll(J i ltlatlpl high ill tili PIY lo Itlllgl 111 aetllllllladie(middot Ill( lopl lillliL 111)(1(1 lIw (ollllil ions of tlil ]lI()(lltlIIIl u ol1tlinpd ipt at l11 11I1 or 1111gt11(1 illt i-1ll1 Ollllll IlPIPltPlltillg 01 p(gtl(pnt of JllUiJtL un tlll 1Hli or (xlla ion rlOI11 II rlll of tisSIll
EIlIlOH COSIIlIHIIO
In Oldpl to H(IIp ill )1lHtPltt pl((iioll illlpIi1I- it i lH((SSHI to slnlldHIdiz(i rigidly 111( Pl()((dlll( 0 illdi(ntpd Oil pnglt- - to J( If lids i dOlH tlip lXIHlinwnlal PIIll is t(middotdllld 10 n ndninlllill
Illlt pl(iioll of (hI ]lIPPllt 1IHllwd Oil til basi of ]llllP llIllJt1 alld Ipsinssollltions call hI jlldgl(J 110111 figllll Hi lileh lio- til HPIlIgl d(intioll oft -illgIP lI1lnSIlIlIIIlnt in lHi((lltagl of Ill( alllOllllt 01 Illhshy1)() 01 lpsins d((PI1I1 iJlld TIl( (1101 PlI(Plltaglt H1( gi (1 101 OJ) to
RUBBER IN 25-ML VOLUMEMG) 004 01 02 03 04
i= I I IZCtOW
fbA ICtU CtCt WW a
01 02 03 04 05 06 07 08 09 100 = RUBBER (PERCENT)
RUBBER IN 25-ML VOLUME (MG) 10 20 30
~ I CtZ
bBOw Ctu CtCt Ww o I~
010 50 100 150 200 250 RUBBER (PERCENT)
RESINS IN 25-ML VOLUME(MG) 10__ __3-0_ 40 50 60 70 60 90 100--_-- 2_-0
Ct~ -r- 1 I OZ
WCt UCt b C wCtW
a o I I 150 250
RESINS (PERCENT) o 10 50 100 200
bllI 1tI W-Yllnl dtd1 ioll I I 11l1 11IlI11 1(111(11 1 III Plll- IlIIIlol1 01 IIim~
bull
bull
bull solution Il basis J o golH of tiSSII (JlILCl-nt (11(11) for (~I) (l)1 til O 1I1
of luhllpl lin 1 III I (I Ill of lUhlJPl nllll laquo I J to 111 nlg of IlSlllgt (Itllillgs on ]iYllyu pllolwh-llrk CO[IJlilll(-(PI with nOHIP Iiltlr lIntl U-lIll allcrture)
RAPID PHOTOlJElRIC DELEHlllNAllON Cn HUBBER AND H1~SINS 33
10 mg of rubber anel1 to 10 mg of resins in a gJ-m1 yolumC For
bull
bull
bull
comparative ptuposes the leslllts arc also calculated on the basis oJvershycentage rubber OL tltsills in 02 gllI of tissul As WOlllL be expcet(d the error increases sOIlHgthlf for 1(lali nmiddotly low COlHell t1llf iOlls oj rllbbeL or resins The curves in figure 1(j s1l0 that ill til(gt Illlge Ol to 10 pCrshyeent of lubber the elTOI rangts Jroll1 abollt Ll to II) ]IlC(lIt abo(~ this mlllc tIlt (ITOl d(((ts(s to (ollsidlItbly ltmiddotss (han 1 1lICPllt of tlH mllollnt ltl((Lmill(d Hil1lilally in tlH (lISl of l(sins analysis (fig 10) the ltLTor is (onsit1eIubly INS than 1 PlLllnt ill (he lallgp of 11 t~) ~() penPII t
In nil ([lSl of lllhblI alld (sins lx(Inltpd tIOIl1 (issups Ol addcltl to tisslle lxtlads (s(( tabhmiddots (i H) illyolillg ll01P o(lllntiolls the eLI01
is hig]wl thun that indilHtld in figllll ((j Im pUIl Ill )])p I tllllllsins solutlOII
COlllUCIIOXFOH IXSOLl-IlLl~ Ilgsqgt(Jg
111 th( Jllo(pdulP ollllillPd 011 paw I till illsolllhll isSII Ipidll( tflpl (xttlw(ioll is (Ptill tlw lIask l(lll till xtlct i l1wdp up to yoltlllH It is not rOllPllipnt (0 IPt()PI qWlIltitati(Ir III(lw[olH a 11(1 pllooll extlnlfs of guuyull I is-lll alll thl1l main t11l111 up (0 YOIUllllmiddot bpCaUHI sllch all additiollal stltp wottld]) tillll-C(JllS11ll1illg Th( Iogiea nll(gtIshynntin is to mnkp tltl lXtlUCt Llld Ipsidup lip to OllillH in till original flask andi llPSStllY 10 llwlno tl OIIpdioll wlHIl (allIlnting [hc llshy
Hults f(JI [hl oll111lC displupd hy till ins()lllbh llsidll( III it l)picat (IXpednHllt (ollsisting of Jhp lppJiea(iolls if was Iollnd llftt at ~iiO ( 02 gill 01 Iuhhll pillS IPill-fl(( lisslI(gt (lollpdll fot llwistUlC ou basis of dlyillp ut lOW 101 ) llOlll-j (lbp(ld only t~ llllUll voiul11P of OOk7D~- OO(lOO(i Ill of lllthyl bolnl(yl 1lIOll( (lplhlli(al-t(Tnltle sp gl () Ii I ll(Hli (j at ~)) -gtitllP tl1(gt 1It101111( () r t is-lIl xt Iadld j sl1lall til( PlIOI dul to Ill(gt insoll1blp Ip~idll is slllall III [0111 ill( wOtk it (all lJp diIpgal(ll(l
]hcon~lIY OF HllIllgl AiO HESIS AIH)gl) TO EXTlIACI OP
GlYlLE TISSlg
Tnl)ll G L(IHpslntillp (ypi(nl llld(~ SllOS (hat all a plngl of HIOK PlI((nt ot lltl pltl( Ilhl)(l acldpd to tllP Itll h iolJut1 InmiddottcJllP xhnet
of guayulp tiSI1( WllS 1l((PllIl Tlli nllintioll flOlll (olllplpU I((OYshy
PIY i within flll pxp(IiIlHuttllIIOI ~illli]llly fnbll Ii llows thn 1111 llYlIUgl of 1O(1~ ])(I(Pllt of gllllYllII 1(-i1l- add(d to II( (pllosol( (xshytrae of IUllY]l t i~HI Is 1l(oPIPI
THl~ (~ Hf (Off Ill of 1111)( J OJ I~il~ lItfI(( In ~(JI1IJk~ Ilf (111 [lI1Il fI2 lIII
0 tlUfllllit i~~I1
Instrument
---- ----~---- bull shy 1(1
Colemun ruono~ltrOUlllt()r 2t) II sJl~ctroJlhOL()lIIeter with 2tJ I iflllllI wnclength Fetting 21 II nntl 0-1111 WU HI hUJl(L _ L U
Ill 7Evolyn photo~lcclrie (olor JU [ imctcr with iO-llIl filler IV (I
H1 0 t I I
llImiddot lUn WII 1011 HIO Wn mil lUulon
10 JIg1111 IUI ml lUl anh Io aLn 111)_I ) III li lU It 2) deg wn2SU DD
Irl JIll II IIr II US II
1110(1 lULa lUI IlK) IJ WU
I( llI Htl tNI 1(111 2tlNI HI 0 221) lllil t2S 0 1~ 10 1~13
In (I 2117 I
10U 1l(J ~ 4 _H_j ___
9middotJIlJ5 10115 10 00 lUU5 flUU 4li (tl03 9(11)
leIlKl 1l~)5 lOOU l1KIr JOIS un 003 OIl Ii
34 lECHNlCAL BULLErIN 920 U S DEPT OF AGRICULlURE
COMPARISON OF PHOTOMETRIC A1D MODJIoIED SPENCE-CALDWfLL METHODS OF RUBBER ANALYSIS
Guayule samples were analyzed by the photQ111etIic method and by bull the modified Spenc(gt-Cnldwell mcthod The values in table 7 represhyselltativ(I of typical results indieate It -atisfactory dcglpe of conformshyjty between the two methods in thl range of tiSSlHH with llHHC than OJ) percent of rubbtImiddot On the bnsis of the amounts determimd the results in this runge for the plmiddotts(nt lIlcthod ayernge apploxinHltely j percent highcr
~LAIII~ 7-(oIllJl(i~on of lltlllrIic (IIri mOtllinl SJl(II(r-(ulri-wall IIIrtlwrl~ of rlrrlIIillillfl 11)1)(1 COIIrll of UI(III
1 Flowers frllm amiddotmonth-oltl nursery plants
YAIIIATJO- OF SIli(LE DETEnt1NATIONS Fnoll TnEIIllIEAN
Rllbbel (Uall8i8-Thc plcCision of thc pLcsent method when gunyule tissues Hr( nnnlyz((1 for rubber may be j udg(d flom I Ill datil presentcd in table H TIl(se dahl -how that thl pplCPlltag( uriation of single determinatiom from nwan yullles with low standllrd enolS ranges from less than 1 to 4 p(gtrlent
R(8in~ wWlsi-r-s lndi(a((1 011 page ~j he INntlts s((uled hy the present phoolllttric nsins llHt hod are not tliltly (olllpalable with those of the grtLVimetri( ncetol1l-cxtlt1(tioll II1etho(l Thjs made it necesSllry to selc(t another lalibllltion staudud-tlll Ipsinous exullate from gullyule shrub-thut gies relatively COllstlllt photometric readshyings (table 5) The resin (olltents of guayule roots branchcs or leavcs usually ran(~e from about) to 1-1middot pelcellt The ple(ision of the present methotf WhCll gUHyule thslllS lIe analyzed for reins may be judged from the datalHmiddotpscllted ill table 9 1h(se data show that the p(lcelltage variatiun of sillgle lhmiddott(Lminntions iLO11 meun ynlnes with low standard NTOrs rangcs from about 05 to 4 percent
bull
bull
bull
bull
bull
RAPID PHOTOMETHIC DElEruIINAlION OJ RUBBEH AND HESINS 35
IAIILE 8-luriation inclieute rubller (mallSM of [1wIIle tissue bll thc 1111O0Illclc metwII
Vnrlntlon~Ilbher I (rom mean
ierCtnl Percelll ~OU -22 ~ 25 +27 ~ 20 +18 ~UO -22---------1_______ 51110 0G6 bullbullbullbullbullbull _bullbull
10 ro ----=ii41075 -01 1000 +11 1010 +13
rlln HI itil 1l9~ 1_ ___ =-~~~
115511 ~ US -111 III II 1575 -13 115 b tiS -I a 111 h WlU +22IIM-(middot bull 11K -1Ja Illi c 1000 +03 1J5H1 W +l)7 ll1imiddot tl 1575 -13
Mcnn 15951 131
1102-11 21fJ() +21l102-h _ ~~)SO -17 1102-c bullbull 21CO +21n02middotd ~OIiO -26
2 r~plusmn Il~ 21151 261 I -~-------bull---__ _~~_~______l-___--_
1 lhe$ 1111($ I1n (or SlIlIIllltS Stpnnltplr PHrilClld IIrtlrdlng 10 1hr prollIlIlr( OIiIIiIl(o(I on Imgt$ 4 to IC ~tcond nUlI1 hlr r(J)[ltnts stl1ndnnl llrrot of tilt 1I1(1111
1_1l1~ n-J(lri(iot in relli(Upound rpoundsins (lllalIsfs of VIOJII( lixsue b1 the lhomillric lII(lloli
-- ---~--- - __-------- shybull I I I I Varlgttton
_________~___ ~~lu_n_Jl_Q_~~~_____ ______I__~_o~S_J frOID lDean
Percent Percentgt458-1 ~65 +41IWtl-li 130 -a2Hli8c aliO +26S41i8-d bull 130 -32
1(-011 34I10Olifgt __ bullbull __ ~--====
li-9~2n 881) -06 li-9~2-b Si5 o ~HH2middot(middot S i5 -6$-H2middotd 000 +1
8851 054
O i5 +6 9 i5 +6 950 -20 U75 +6
H-liG3o-n bull -1 n-li6~b bull __ _ -IH-IWH +4H-l61511 bull -1
1tmiddottlU
62~-lI __ 62~-b ij24-( bull OH-Ji
(-Ull
I rll(St oluls nre tor separately ~xlrflCled SllllllllCS IlctOrdlug lO procedure outllned ou pages 4 to 10 i Secoud number r~prtgeulS stulldMd error of lIe menn
36 TECHNICAL BULLETIN 920 t ~ DEPT OF A(]RICCLTCRE
ReUUER A~ALYSrS I~ CRCOE-RcuUER PROOCCTS
Sew rapid photometric m(lthod~fol the ddellllinttion of rubber and reii Hi ill uaYllp ti--ut htp lllell pIPHnl pd oil pag( ~l to In A brief H1111111tlY of It similar rnpid llHthod fm 1I1hb~rllnltlysis of u1lulcanizNl tlIldp lubbll pl(Hlmtlt whielt i~ bn-(tldo on the prill o
ciples dehtilcd tlllLe follows Duplltate nt-gm sllmph of the finely cliyiliNl IlInttlitiup wlirllll out [~ei-()l (all hl lIf((tinmiddotjv INd to lt1iyidl till alllpl) TIll kltolll-olubll portion of till )111(11( tlrc di-olved a- indh-Htpd fot thmiddot lllnkill~ of -tlllHlunlluhhll olutiou Oil Pt 1II hut tIl IUlIp Hn lIn l-fplImiddotd 10 lHI-ml rolllllltti( fln-k antil1ltld(lup to Olllll1l The bnlulUp or till JllO(ldllll i- thatutlilllll on paWs -1- 1 IHI Ii 111( 1(111 1- nIP IXPIP--pd nil til IHi or Iw oligiJla w(lullt of I Ill (I11l1p-I1l11Ilt1 1)(0(11(1
Hupitl PlllimiPJojgtiWllllllllh llIltllOd~ fOJ Ihl llPtlmiddotminntion of ImiddotUlJbll tlnd 1(-illo- ill -111111 Illllph of gutlYllll tiUl IIll dl-eli)ed 111() IlltlY d~o Ill nltlI1lld fOl III Iwl Illhlwl- and l~iJlmiddotb(lLiJlg plant TIllt l[Olllhup hns nlo b(l1l ntuptpl fot IIH lltlIll1illtltioll of lllhbpl ill 11lHhrublwl Pl(Jdlld~ HIIl 1111 hI ndaptld JoJ IIll ann lysis of ynt1J(gt( ic lllbbl[- The llllthmb HIP 1gtn(11 fill tIll fol1owill plimiph- III Grinding
tIll PIOPlly driPl t i~lIl 01 Ul tillg tIll pnHhHt to tll l((lllilllllh~lel of filWlH-- til plllllit qIHlIllilnth( lXIIHtioll 01 IIlbhlI 01 1(--IJl- () llsing oXWllutld olnuh (kttoJls IIt(talp and() fllltil for LIbbel and IH(ltIlIlyptIJllIllIoolYlnJld-o flJllh 101 niJlsl with t(lathelr high IlPililig points 111 to n C) l]olle or in mixt tIll thllt Pll mit tlll rnphllxututioll of luhll(l OJ [middot(ill ill ~() to (l mi1lutp It r(latiwly high 1lllIllllltlltP Ill to 1~11 ) l) lllllipitntillu till luhblI OL Imiddot(ill frolll aliquot () f till oltn ion I IlIlllI-i () f Hlltabhmiddot pl(~(i]litallt (willifhmiddotd lthmwl fOl IIlhlHI Hild llitlifild lllr fOJ JP-illl t~) IIlHkillphotollllliilPIIIIiIlof PlllPlltal of liht tLaIlS mittUl(P lIftlI IlIlbll (II Il in PIlipitalioll 11 II WI( Iplllh thnt (limiJlall till PIIOl dill 10 xtralllOlh (0101 (till dptl1minntinll Iph jill 011 tIll dtwlopllIlJIl of H HIli rOI1ll tlllbidity 111 hpl than I (olot rI
jJlIlpOP-ofallnlyi-I ( p(lllil1thb IIllijOI1ll turbidity or 1llt[lIinmiddotd d(ltl of jgtIp(ii(JlI l)~ lIltlkillU tIl plllltollllmiddottri( ntdillU al tandinu tiJlH~ (dlllilll wlli(h IhlllH(lill-- IP 1llutinmiddotly tnhll) t1ll1t an hlsl~1 oil the (oJlItlIlllItion of IIlhlHI Ill I(ill (lIPIipitat((L
TIll -I(p ill till jll()(Plhul HIP 1-- follOylt (1) 1l~UIIL uJ1lplls of thwl UJfJlllHl (II tliddl(l HUt dlipd 11Illtplial an lXIllltel with11 Ill of till nlnll ill t (oU tlllltIPlll[gtPImiddotatlup oil Iath at 11 Cbull fol 11 minutl I) iIP1lIin(middot(lohd til( (XUtllhllll Jltldl lip to It middotml ynlmlll til( (nlifild by (Illlifllgiuu HlId thlPl IlI nliql1ot of tIl (IalioPlllxUlltl nll Uillltlmiddotll(t to l-llll OIlIIlIllril fiuk- (1) For a trial Ilnditlg 0111 III tlll j liJmiddot~t IllHII IIjI to Ohlllll with lilt Pll shy(ilitnnl a 1(11 it 111 (Dod fill llli lIut ( ptotoJIIltlil IPtlllillg-- of pllllntnl or liuht tlUtllIlillal(I oil n (lpel OphotnJlllllI at rase hng-tlt (If 11 llJ Ill Ol It lollllil1lPtImiddott lloyidld with tIll P10]11 I 1110110shy
Ihlolllltt hmiddot Ii1llI Olllhi lIatioll for -1IpItillg UJlproXilll1l tply Wtl P ]Plwth )0 mp are HHlltk TIll Illldillg lliJtaillld fol tIlt 4-milutl tliall(~ll-
bull
bull
bull
RAPID PHOTO~IETRIC DETERIINATIOX OF R(BBER AXD RESINS 37
ing are referred to a table of equhmiddottllut~ previously p1(pa1elt1 on the
bull basis of 4-minute reac1inJ~ for tilE nmge of lot1telltlatiol1- of rubber or resins to bE elHOlll1t(led tmd gidn thtmiddot -tnnlillfr tillIP fill rUbbEt or resins aiter prE(ipitlltiol1 lwfolE photoIllNliI j(tltlill1 un IUade The r(middotnmining dllplllatt aliquot lll then HHllil up te ol1l1Jle and lpoundadillg ale marle ut the -tandillfr tiUlE iudklltll ill rhl tall1lmiddot for the final r(adillg~ -1) 111( milli1lnm or p(tCPlltllt- of lllhbpL (II 1(-in pr(s(nt are rpadholU a prlpan(l table of lquiltlput for tlll photoshymetric readings h1~l(l ill pnell e1-E on pxpPlilmlItal lhln 1111(1 u-ing as stimtlltlds pure luhbll in 1l1bbtl milllYb aIHI guaYllh ll-ill- lxIHlatt~ in resins detNIl1111lttion I
LlTERATlRE CLTED
(1) lUnSbull 1fl36 THE mURMIXTIOS IIF IOTA RE I III OOl THER llT~II
F1 bullrol IlY U(T1l0fll UfSlfi ~rrnrl r flm lt1 KEYS TI Bill Chern 114 44J-l59 illns
t1 ~ICPHHlObullbull T 1J3bull~ lUTHOO roa THE PtRInCAnu Or a(lIUl IRrIlHU It of TIn
PLRIHEU Htllllflt [ i Bill lallllall 111 Rmiddot 711middotj iIlus
I ) RHBERG P B Ul5 A METHIlO Or ~u(ronrll-nl Hi tIII rUIl[1 f71 ii illlI
bull 14 Hoss W flbull and HARDESTY J O
llH IR1ltDII Of HfITilIZfmiddotR DllIJS ltt 1 Yl fll Off gI bern JIIIlI i ~middotmiddotlf IIl
101 SPEltCE D nnd CuoWELr ~I L 1933 DETER~n-ATIOo OF RtBBER Ii nrllllpoundRBfR Iusr 1uI II1 amI
Em~ifl cttIliIa~~ r Ell i 71middot7i l11 (HI WALTER E D
1U44 ISO~nlS OF PRTlltSrr 1trHpoundV bull l UI n W lHHt (Tnmiddot 1ETS FROM GiYI l~iIl lItr Clttrn SII J UI titJ middotn9--C1 ilIu
17 J YOEbullbullr H lO~( roLORIlETRT 771 IPmiddot nl -W Yurk f H Plrwptric hmica
naly-II rimttry lUll XphHHlnmiddot~ y 1 1
11
HI) ~ fPHELolzTRf 57 111bull Lin xw Yk t H lt PhmeHt CblUlmiddot ila AnaiY~l~-(H lithrry and XIhmiddotILpfIY Y wirh enomiddot rrJlllrjr hy H KtlJnJU11 I
t~1I --- and ~ARVER L 1f41 nlua-w ~in L liLhr IS IP ll~ XIW Yrk
bull For-sale by th~ ~a~fr1nt~nf1ent Dt~c~~ogtnts-~ s t1i rArnn~ut Pn~~~ tJffieshy
Washington 5 D C bull Pl lU ~nts
bull
bull
bull
RAPID PHOTOMETRIC DETE~MINATION OF RUBBER AND RESINS 3]
centrations From a casual inspection of these CUlTes it would appeltr that Beers law does not hold Actual tests indicitted that Beers law was applicable only within a narrow range in the upper portion of the curves The analyticlil results on the basis of photornetric readings nre therefore calculated by direct reference to calibration curves or from reference tables of equivalent values bllscd on the cnlibllltion curves
Calibration curves for kok-saghyz alld heyea lI11tulltl rubbers and Buna S (GR-S Chem Gum IV Goodyear) and butyl (GR-I Standshyard Oil Co Protoc) sYJlthetic rubbers are hOWllil1 figure 15 The samples of kok-saghyz rubber were furnished by the Diyision of Rubshy
100
90 ~I) ()
z 0
1amp1 a
~ a
80
70
60
s 1amp1 ~ ~ 0 ~ KOj-SAGHYZ 0 l Il
50
HEVEA~ ~
40
100
90
~ 0 80z Q 70a Co)
a 60 ~ 0 0 x 50Il
40 ~----~~----~------~------~------~--~ o 2 3 4 5
RUBBER IN 25-ML VOLUME(MG)
FmUIlE 15-CaJiblation curves fOl kok-snghyz h(YCII Bunn S lind butyl rubb~ls (Readings on gy((yn photoelectric colorimeter with i20-lIIp filtpl and 6-ml aperture)
32 TECHNICAl BUIJLETIN [)20) 1 S DEP1 OF AGrnCUIlfURE
Iwt Plant JIl(I~t ignlioll of thi BlII(un and (1( l))(parcd according to 11( SPltI1((-Culd (]] (6) PIO(((lllll Hlpt pal( CLPPe was (xtmch(L with acetone blI()Ieit W 1I(gt(11l a ttnlldal(l
SEXSlllVllY Ol~ llETJIonS
By lip pIO((l(II11P olltlillP(l 011 ]Hlg( +n Iowa (lOOl IIIg (11 1111i(l0shygmm (gHlllllla) of 1hblI ill a 2)1111 yoltll1ll (all )(gt dltpltld Oil tltl Col(man (lohlP mOIlWhlOl1lHlOl l-I)((t 101 l1lOt 0111 ci( I ill1ilnlly 001 mg of Iublwr ill a 2J-1ll1 n]ulllP Illay bl Ilad Oil till EnI)1I photoshyllectlie (O]oLillllt(I Thll ya lllll- 011 tilt IHl-i- (J I (xl ad iOI1 fmlll 02 gill of til-lI tH(JI(lillg to tllP -lllndal(l jll()(pdull 1(PIPStlIt IlO()2J tlnd 002) P(IT(lIt of llIbl1ll IPI)(((inly bull1t1lollgh -lI1t low allils can be d((d(middot(1 il lIoullt1 Ill IPtllizpd thnt till PIIOl ill PlI(Plltng( or tll( al110unt dltlIllIilll(J i ltlatlpl high ill tili PIY lo Itlllgl 111 aetllllllladie(middot Ill( lopl lillliL 111)(1(1 lIw (ollllil ions of tlil ]lI()(lltlIIIl u ol1tlinpd ipt at l11 11I1 or 1111gt11(1 illt i-1ll1 Ollllll IlPIPltPlltillg 01 p(gtl(pnt of JllUiJtL un tlll 1Hli or (xlla ion rlOI11 II rlll of tisSIll
EIlIlOH COSIIlIHIIO
In Oldpl to H(IIp ill )1lHtPltt pl((iioll illlpIi1I- it i lH((SSHI to slnlldHIdiz(i rigidly 111( Pl()((dlll( 0 illdi(ntpd Oil pnglt- - to J( If lids i dOlH tlip lXIHlinwnlal PIIll is t(middotdllld 10 n ndninlllill
Illlt pl(iioll of (hI ]lIPPllt 1IHllwd Oil til basi of ]llllP llIllJt1 alld Ipsinssollltions call hI jlldgl(J 110111 figllll Hi lileh lio- til HPIlIgl d(intioll oft -illgIP lI1lnSIlIlIIIlnt in lHi((lltagl of Ill( alllOllllt 01 Illhshy1)() 01 lpsins d((PI1I1 iJlld TIl( (1101 PlI(Plltaglt H1( gi (1 101 OJ) to
RUBBER IN 25-ML VOLUMEMG) 004 01 02 03 04
i= I I IZCtOW
fbA ICtU CtCt WW a
01 02 03 04 05 06 07 08 09 100 = RUBBER (PERCENT)
RUBBER IN 25-ML VOLUME (MG) 10 20 30
~ I CtZ
bBOw Ctu CtCt Ww o I~
010 50 100 150 200 250 RUBBER (PERCENT)
RESINS IN 25-ML VOLUME(MG) 10__ __3-0_ 40 50 60 70 60 90 100--_-- 2_-0
Ct~ -r- 1 I OZ
WCt UCt b C wCtW
a o I I 150 250
RESINS (PERCENT) o 10 50 100 200
bllI 1tI W-Yllnl dtd1 ioll I I 11l1 11IlI11 1(111(11 1 III Plll- IlIIIlol1 01 IIim~
bull
bull
bull solution Il basis J o golH of tiSSII (JlILCl-nt (11(11) for (~I) (l)1 til O 1I1
of luhllpl lin 1 III I (I Ill of lUhlJPl nllll laquo I J to 111 nlg of IlSlllgt (Itllillgs on ]iYllyu pllolwh-llrk CO[IJlilll(-(PI with nOHIP Iiltlr lIntl U-lIll allcrture)
RAPID PHOTOlJElRIC DELEHlllNAllON Cn HUBBER AND H1~SINS 33
10 mg of rubber anel1 to 10 mg of resins in a gJ-m1 yolumC For
bull
bull
bull
comparative ptuposes the leslllts arc also calculated on the basis oJvershycentage rubber OL tltsills in 02 gllI of tissul As WOlllL be expcet(d the error increases sOIlHgthlf for 1(lali nmiddotly low COlHell t1llf iOlls oj rllbbeL or resins The curves in figure 1(j s1l0 that ill til(gt Illlge Ol to 10 pCrshyeent of lubber the elTOI rangts Jroll1 abollt Ll to II) ]IlC(lIt abo(~ this mlllc tIlt (ITOl d(((ts(s to (ollsidlItbly ltmiddotss (han 1 1lICPllt of tlH mllollnt ltl((Lmill(d Hil1lilally in tlH (lISl of l(sins analysis (fig 10) the ltLTor is (onsit1eIubly INS than 1 PlLllnt ill (he lallgp of 11 t~) ~() penPII t
In nil ([lSl of lllhblI alld (sins lx(Inltpd tIOIl1 (issups Ol addcltl to tisslle lxtlads (s(( tabhmiddots (i H) illyolillg ll01P o(lllntiolls the eLI01
is hig]wl thun that indilHtld in figllll ((j Im pUIl Ill )])p I tllllllsins solutlOII
COlllUCIIOXFOH IXSOLl-IlLl~ Ilgsqgt(Jg
111 th( Jllo(pdulP ollllillPd 011 paw I till illsolllhll isSII Ipidll( tflpl (xttlw(ioll is (Ptill tlw lIask l(lll till xtlct i l1wdp up to yoltlllH It is not rOllPllipnt (0 IPt()PI qWlIltitati(Ir III(lw[olH a 11(1 pllooll extlnlfs of guuyull I is-lll alll thl1l main t11l111 up (0 YOIUllllmiddot bpCaUHI sllch all additiollal stltp wottld]) tillll-C(JllS11ll1illg Th( Iogiea nll(gtIshynntin is to mnkp tltl lXtlUCt Llld Ipsidup lip to OllillH in till original flask andi llPSStllY 10 llwlno tl OIIpdioll wlHIl (allIlnting [hc llshy
Hults f(JI [hl oll111lC displupd hy till ins()lllbh llsidll( III it l)picat (IXpednHllt (ollsisting of Jhp lppJiea(iolls if was Iollnd llftt at ~iiO ( 02 gill 01 Iuhhll pillS IPill-fl(( lisslI(gt (lollpdll fot llwistUlC ou basis of dlyillp ut lOW 101 ) llOlll-j (lbp(ld only t~ llllUll voiul11P of OOk7D~- OO(lOO(i Ill of lllthyl bolnl(yl 1lIOll( (lplhlli(al-t(Tnltle sp gl () Ii I ll(Hli (j at ~)) -gtitllP tl1(gt 1It101111( () r t is-lIl xt Iadld j sl1lall til( PlIOI dul to Ill(gt insoll1blp Ip~idll is slllall III [0111 ill( wOtk it (all lJp diIpgal(ll(l
]hcon~lIY OF HllIllgl AiO HESIS AIH)gl) TO EXTlIACI OP
GlYlLE TISSlg
Tnl)ll G L(IHpslntillp (ypi(nl llld(~ SllOS (hat all a plngl of HIOK PlI((nt ot lltl pltl( Ilhl)(l acldpd to tllP Itll h iolJut1 InmiddottcJllP xhnet
of guayulp tiSI1( WllS 1l((PllIl Tlli nllintioll flOlll (olllplpU I((OYshy
PIY i within flll pxp(IiIlHuttllIIOI ~illli]llly fnbll Ii llows thn 1111 llYlIUgl of 1O(1~ ])(I(Pllt of gllllYllII 1(-i1l- add(d to II( (pllosol( (xshytrae of IUllY]l t i~HI Is 1l(oPIPI
THl~ (~ Hf (Off Ill of 1111)( J OJ I~il~ lItfI(( In ~(JI1IJk~ Ilf (111 [lI1Il fI2 lIII
0 tlUfllllit i~~I1
Instrument
---- ----~---- bull shy 1(1
Colemun ruono~ltrOUlllt()r 2t) II sJl~ctroJlhOL()lIIeter with 2tJ I iflllllI wnclength Fetting 21 II nntl 0-1111 WU HI hUJl(L _ L U
Ill 7Evolyn photo~lcclrie (olor JU [ imctcr with iO-llIl filler IV (I
H1 0 t I I
llImiddot lUn WII 1011 HIO Wn mil lUulon
10 JIg1111 IUI ml lUl anh Io aLn 111)_I ) III li lU It 2) deg wn2SU DD
Irl JIll II IIr II US II
1110(1 lULa lUI IlK) IJ WU
I( llI Htl tNI 1(111 2tlNI HI 0 221) lllil t2S 0 1~ 10 1~13
In (I 2117 I
10U 1l(J ~ 4 _H_j ___
9middotJIlJ5 10115 10 00 lUU5 flUU 4li (tl03 9(11)
leIlKl 1l~)5 lOOU l1KIr JOIS un 003 OIl Ii
34 lECHNlCAL BULLErIN 920 U S DEPT OF AGRICULlURE
COMPARISON OF PHOTOMETRIC A1D MODJIoIED SPENCE-CALDWfLL METHODS OF RUBBER ANALYSIS
Guayule samples were analyzed by the photQ111etIic method and by bull the modified Spenc(gt-Cnldwell mcthod The values in table 7 represhyselltativ(I of typical results indieate It -atisfactory dcglpe of conformshyjty between the two methods in thl range of tiSSlHH with llHHC than OJ) percent of rubbtImiddot On the bnsis of the amounts determimd the results in this runge for the plmiddotts(nt lIlcthod ayernge apploxinHltely j percent highcr
~LAIII~ 7-(oIllJl(i~on of lltlllrIic (IIri mOtllinl SJl(II(r-(ulri-wall IIIrtlwrl~ of rlrrlIIillillfl 11)1)(1 COIIrll of UI(III
1 Flowers frllm amiddotmonth-oltl nursery plants
YAIIIATJO- OF SIli(LE DETEnt1NATIONS Fnoll TnEIIllIEAN
Rllbbel (Uall8i8-Thc plcCision of thc pLcsent method when gunyule tissues Hr( nnnlyz((1 for rubber may be j udg(d flom I Ill datil presentcd in table H TIl(se dahl -how that thl pplCPlltag( uriation of single determinatiom from nwan yullles with low standllrd enolS ranges from less than 1 to 4 p(gtrlent
R(8in~ wWlsi-r-s lndi(a((1 011 page ~j he INntlts s((uled hy the present phoolllttric nsins llHt hod are not tliltly (olllpalable with those of the grtLVimetri( ncetol1l-cxtlt1(tioll II1etho(l Thjs made it necesSllry to selc(t another lalibllltion staudud-tlll Ipsinous exullate from gullyule shrub-thut gies relatively COllstlllt photometric readshyings (table 5) The resin (olltents of guayule roots branchcs or leavcs usually ran(~e from about) to 1-1middot pelcellt The ple(ision of the present methotf WhCll gUHyule thslllS lIe analyzed for reins may be judged from the datalHmiddotpscllted ill table 9 1h(se data show that the p(lcelltage variatiun of sillgle lhmiddott(Lminntions iLO11 meun ynlnes with low standard NTOrs rangcs from about 05 to 4 percent
bull
bull
bull
bull
bull
RAPID PHOTOMETHIC DElEruIINAlION OJ RUBBEH AND HESINS 35
IAIILE 8-luriation inclieute rubller (mallSM of [1wIIle tissue bll thc 1111O0Illclc metwII
Vnrlntlon~Ilbher I (rom mean
ierCtnl Percelll ~OU -22 ~ 25 +27 ~ 20 +18 ~UO -22---------1_______ 51110 0G6 bullbullbullbullbullbull _bullbull
10 ro ----=ii41075 -01 1000 +11 1010 +13
rlln HI itil 1l9~ 1_ ___ =-~~~
115511 ~ US -111 III II 1575 -13 115 b tiS -I a 111 h WlU +22IIM-(middot bull 11K -1Ja Illi c 1000 +03 1J5H1 W +l)7 ll1imiddot tl 1575 -13
Mcnn 15951 131
1102-11 21fJ() +21l102-h _ ~~)SO -17 1102-c bullbull 21CO +21n02middotd ~OIiO -26
2 r~plusmn Il~ 21151 261 I -~-------bull---__ _~~_~______l-___--_
1 lhe$ 1111($ I1n (or SlIlIIllltS Stpnnltplr PHrilClld IIrtlrdlng 10 1hr prollIlIlr( OIiIIiIl(o(I on Imgt$ 4 to IC ~tcond nUlI1 hlr r(J)[ltnts stl1ndnnl llrrot of tilt 1I1(1111
1_1l1~ n-J(lri(iot in relli(Upound rpoundsins (lllalIsfs of VIOJII( lixsue b1 the lhomillric lII(lloli
-- ---~--- - __-------- shybull I I I I Varlgttton
_________~___ ~~lu_n_Jl_Q_~~~_____ ______I__~_o~S_J frOID lDean
Percent Percentgt458-1 ~65 +41IWtl-li 130 -a2Hli8c aliO +26S41i8-d bull 130 -32
1(-011 34I10Olifgt __ bullbull __ ~--====
li-9~2n 881) -06 li-9~2-b Si5 o ~HH2middot(middot S i5 -6$-H2middotd 000 +1
8851 054
O i5 +6 9 i5 +6 950 -20 U75 +6
H-liG3o-n bull -1 n-li6~b bull __ _ -IH-IWH +4H-l61511 bull -1
1tmiddottlU
62~-lI __ 62~-b ij24-( bull OH-Ji
(-Ull
I rll(St oluls nre tor separately ~xlrflCled SllllllllCS IlctOrdlug lO procedure outllned ou pages 4 to 10 i Secoud number r~prtgeulS stulldMd error of lIe menn
36 TECHNICAL BULLETIN 920 t ~ DEPT OF A(]RICCLTCRE
ReUUER A~ALYSrS I~ CRCOE-RcuUER PROOCCTS
Sew rapid photometric m(lthod~fol the ddellllinttion of rubber and reii Hi ill uaYllp ti--ut htp lllell pIPHnl pd oil pag( ~l to In A brief H1111111tlY of It similar rnpid llHthod fm 1I1hb~rllnltlysis of u1lulcanizNl tlIldp lubbll pl(Hlmtlt whielt i~ bn-(tldo on the prill o
ciples dehtilcd tlllLe follows Duplltate nt-gm sllmph of the finely cliyiliNl IlInttlitiup wlirllll out [~ei-()l (all hl lIf((tinmiddotjv INd to lt1iyidl till alllpl) TIll kltolll-olubll portion of till )111(11( tlrc di-olved a- indh-Htpd fot thmiddot lllnkill~ of -tlllHlunlluhhll olutiou Oil Pt 1II hut tIl IUlIp Hn lIn l-fplImiddotd 10 lHI-ml rolllllltti( fln-k antil1ltld(lup to Olllll1l The bnlulUp or till JllO(ldllll i- thatutlilllll on paWs -1- 1 IHI Ii 111( 1(111 1- nIP IXPIP--pd nil til IHi or Iw oligiJla w(lullt of I Ill (I11l1p-I1l11Ilt1 1)(0(11(1
Hupitl PlllimiPJojgtiWllllllllh llIltllOd~ fOJ Ihl llPtlmiddotminntion of ImiddotUlJbll tlnd 1(-illo- ill -111111 Illllph of gutlYllll tiUl IIll dl-eli)ed 111() IlltlY d~o Ill nltlI1lld fOl III Iwl Illhlwl- and l~iJlmiddotb(lLiJlg plant TIllt l[Olllhup hns nlo b(l1l ntuptpl fot IIH lltlIll1illtltioll of lllhbpl ill 11lHhrublwl Pl(Jdlld~ HIIl 1111 hI ndaptld JoJ IIll ann lysis of ynt1J(gt( ic lllbbl[- The llllthmb HIP 1gtn(11 fill tIll fol1owill plimiph- III Grinding
tIll PIOPlly driPl t i~lIl 01 Ul tillg tIll pnHhHt to tll l((lllilllllh~lel of filWlH-- til plllllit qIHlIllilnth( lXIIHtioll 01 IIlbhlI 01 1(--IJl- () llsing oXWllutld olnuh (kttoJls IIt(talp and() fllltil for LIbbel and IH(ltIlIlyptIJllIllIoolYlnJld-o flJllh 101 niJlsl with t(lathelr high IlPililig points 111 to n C) l]olle or in mixt tIll thllt Pll mit tlll rnphllxututioll of luhll(l OJ [middot(ill ill ~() to (l mi1lutp It r(latiwly high 1lllIllllltlltP Ill to 1~11 ) l) lllllipitntillu till luhblI OL Imiddot(ill frolll aliquot () f till oltn ion I IlIlllI-i () f Hlltabhmiddot pl(~(i]litallt (willifhmiddotd lthmwl fOl IIlhlHI Hild llitlifild lllr fOJ JP-illl t~) IIlHkillphotollllliilPIIIIiIlof PlllPlltal of liht tLaIlS mittUl(P lIftlI IlIlbll (II Il in PIlipitalioll 11 II WI( Iplllh thnt (limiJlall till PIIOl dill 10 xtralllOlh (0101 (till dptl1minntinll Iph jill 011 tIll dtwlopllIlJIl of H HIli rOI1ll tlllbidity 111 hpl than I (olot rI
jJlIlpOP-ofallnlyi-I ( p(lllil1thb IIllijOI1ll turbidity or 1llt[lIinmiddotd d(ltl of jgtIp(ii(JlI l)~ lIltlkillU tIl plllltollllmiddottri( ntdillU al tandinu tiJlH~ (dlllilll wlli(h IhlllH(lill-- IP 1llutinmiddotly tnhll) t1ll1t an hlsl~1 oil the (oJlItlIlllItion of IIlhlHI Ill I(ill (lIPIipitat((L
TIll -I(p ill till jll()(Plhul HIP 1-- follOylt (1) 1l~UIIL uJ1lplls of thwl UJfJlllHl (II tliddl(l HUt dlipd 11Illtplial an lXIllltel with11 Ill of till nlnll ill t (oU tlllltIPlll[gtPImiddotatlup oil Iath at 11 Cbull fol 11 minutl I) iIP1lIin(middot(lohd til( (XUtllhllll Jltldl lip to It middotml ynlmlll til( (nlifild by (Illlifllgiuu HlId thlPl IlI nliql1ot of tIl (IalioPlllxUlltl nll Uillltlmiddotll(t to l-llll OIlIIlIllril fiuk- (1) For a trial Ilnditlg 0111 III tlll j liJmiddot~t IllHII IIjI to Ohlllll with lilt Pll shy(ilitnnl a 1(11 it 111 (Dod fill llli lIut ( ptotoJIIltlil IPtlllillg-- of pllllntnl or liuht tlUtllIlillal(I oil n (lpel OphotnJlllllI at rase hng-tlt (If 11 llJ Ill Ol It lollllil1lPtImiddott lloyidld with tIll P10]11 I 1110110shy
Ihlolllltt hmiddot Ii1llI Olllhi lIatioll for -1IpItillg UJlproXilll1l tply Wtl P ]Plwth )0 mp are HHlltk TIll Illldillg lliJtaillld fol tIlt 4-milutl tliall(~ll-
bull
bull
bull
RAPID PHOTO~IETRIC DETERIINATIOX OF R(BBER AXD RESINS 37
ing are referred to a table of equhmiddottllut~ previously p1(pa1elt1 on the
bull basis of 4-minute reac1inJ~ for tilE nmge of lot1telltlatiol1- of rubber or resins to bE elHOlll1t(led tmd gidn thtmiddot -tnnlillfr tillIP fill rUbbEt or resins aiter prE(ipitlltiol1 lwfolE photoIllNliI j(tltlill1 un IUade The r(middotnmining dllplllatt aliquot lll then HHllil up te ol1l1Jle and lpoundadillg ale marle ut the -tandillfr tiUlE iudklltll ill rhl tall1lmiddot for the final r(adillg~ -1) 111( milli1lnm or p(tCPlltllt- of lllhbpL (II 1(-in pr(s(nt are rpadholU a prlpan(l table of lquiltlput for tlll photoshymetric readings h1~l(l ill pnell e1-E on pxpPlilmlItal lhln 1111(1 u-ing as stimtlltlds pure luhbll in 1l1bbtl milllYb aIHI guaYllh ll-ill- lxIHlatt~ in resins detNIl1111lttion I
LlTERATlRE CLTED
(1) lUnSbull 1fl36 THE mURMIXTIOS IIF IOTA RE I III OOl THER llT~II
F1 bullrol IlY U(T1l0fll UfSlfi ~rrnrl r flm lt1 KEYS TI Bill Chern 114 44J-l59 illns
t1 ~ICPHHlObullbull T 1J3bull~ lUTHOO roa THE PtRInCAnu Or a(lIUl IRrIlHU It of TIn
PLRIHEU Htllllflt [ i Bill lallllall 111 Rmiddot 711middotj iIlus
I ) RHBERG P B Ul5 A METHIlO Or ~u(ronrll-nl Hi tIII rUIl[1 f71 ii illlI
bull 14 Hoss W flbull and HARDESTY J O
llH IR1ltDII Of HfITilIZfmiddotR DllIJS ltt 1 Yl fll Off gI bern JIIIlI i ~middotmiddotlf IIl
101 SPEltCE D nnd CuoWELr ~I L 1933 DETER~n-ATIOo OF RtBBER Ii nrllllpoundRBfR Iusr 1uI II1 amI
Em~ifl cttIliIa~~ r Ell i 71middot7i l11 (HI WALTER E D
1U44 ISO~nlS OF PRTlltSrr 1trHpoundV bull l UI n W lHHt (Tnmiddot 1ETS FROM GiYI l~iIl lItr Clttrn SII J UI titJ middotn9--C1 ilIu
17 J YOEbullbullr H lO~( roLORIlETRT 771 IPmiddot nl -W Yurk f H Plrwptric hmica
naly-II rimttry lUll XphHHlnmiddot~ y 1 1
11
HI) ~ fPHELolzTRf 57 111bull Lin xw Yk t H lt PhmeHt CblUlmiddot ila AnaiY~l~-(H lithrry and XIhmiddotILpfIY Y wirh enomiddot rrJlllrjr hy H KtlJnJU11 I
t~1I --- and ~ARVER L 1f41 nlua-w ~in L liLhr IS IP ll~ XIW Yrk
bull For-sale by th~ ~a~fr1nt~nf1ent Dt~c~~ogtnts-~ s t1i rArnn~ut Pn~~~ tJffieshy
Washington 5 D C bull Pl lU ~nts
32 TECHNICAl BUIJLETIN [)20) 1 S DEP1 OF AGrnCUIlfURE
Iwt Plant JIl(I~t ignlioll of thi BlII(un and (1( l))(parcd according to 11( SPltI1((-Culd (]] (6) PIO(((lllll Hlpt pal( CLPPe was (xtmch(L with acetone blI()Ieit W 1I(gt(11l a ttnlldal(l
SEXSlllVllY Ol~ llETJIonS
By lip pIO((l(II11P olltlillP(l 011 ]Hlg( +n Iowa (lOOl IIIg (11 1111i(l0shygmm (gHlllllla) of 1hblI ill a 2)1111 yoltll1ll (all )(gt dltpltld Oil tltl Col(man (lohlP mOIlWhlOl1lHlOl l-I)((t 101 l1lOt 0111 ci( I ill1ilnlly 001 mg of Iublwr ill a 2J-1ll1 n]ulllP Illay bl Ilad Oil till EnI)1I photoshyllectlie (O]oLillllt(I Thll ya lllll- 011 tilt IHl-i- (J I (xl ad iOI1 fmlll 02 gill of til-lI tH(JI(lillg to tllP -lllndal(l jll()(pdull 1(PIPStlIt IlO()2J tlnd 002) P(IT(lIt of llIbl1ll IPI)(((inly bull1t1lollgh -lI1t low allils can be d((d(middot(1 il lIoullt1 Ill IPtllizpd thnt till PIIOl ill PlI(Plltng( or tll( al110unt dltlIllIilll(J i ltlatlpl high ill tili PIY lo Itlllgl 111 aetllllllladie(middot Ill( lopl lillliL 111)(1(1 lIw (ollllil ions of tlil ]lI()(lltlIIIl u ol1tlinpd ipt at l11 11I1 or 1111gt11(1 illt i-1ll1 Ollllll IlPIPltPlltillg 01 p(gtl(pnt of JllUiJtL un tlll 1Hli or (xlla ion rlOI11 II rlll of tisSIll
EIlIlOH COSIIlIHIIO
In Oldpl to H(IIp ill )1lHtPltt pl((iioll illlpIi1I- it i lH((SSHI to slnlldHIdiz(i rigidly 111( Pl()((dlll( 0 illdi(ntpd Oil pnglt- - to J( If lids i dOlH tlip lXIHlinwnlal PIIll is t(middotdllld 10 n ndninlllill
Illlt pl(iioll of (hI ]lIPPllt 1IHllwd Oil til basi of ]llllP llIllJt1 alld Ipsinssollltions call hI jlldgl(J 110111 figllll Hi lileh lio- til HPIlIgl d(intioll oft -illgIP lI1lnSIlIlIIIlnt in lHi((lltagl of Ill( alllOllllt 01 Illhshy1)() 01 lpsins d((PI1I1 iJlld TIl( (1101 PlI(Plltaglt H1( gi (1 101 OJ) to
RUBBER IN 25-ML VOLUMEMG) 004 01 02 03 04
i= I I IZCtOW
fbA ICtU CtCt WW a
01 02 03 04 05 06 07 08 09 100 = RUBBER (PERCENT)
RUBBER IN 25-ML VOLUME (MG) 10 20 30
~ I CtZ
bBOw Ctu CtCt Ww o I~
010 50 100 150 200 250 RUBBER (PERCENT)
RESINS IN 25-ML VOLUME(MG) 10__ __3-0_ 40 50 60 70 60 90 100--_-- 2_-0
Ct~ -r- 1 I OZ
WCt UCt b C wCtW
a o I I 150 250
RESINS (PERCENT) o 10 50 100 200
bllI 1tI W-Yllnl dtd1 ioll I I 11l1 11IlI11 1(111(11 1 III Plll- IlIIIlol1 01 IIim~
bull
bull
bull solution Il basis J o golH of tiSSII (JlILCl-nt (11(11) for (~I) (l)1 til O 1I1
of luhllpl lin 1 III I (I Ill of lUhlJPl nllll laquo I J to 111 nlg of IlSlllgt (Itllillgs on ]iYllyu pllolwh-llrk CO[IJlilll(-(PI with nOHIP Iiltlr lIntl U-lIll allcrture)
RAPID PHOTOlJElRIC DELEHlllNAllON Cn HUBBER AND H1~SINS 33
10 mg of rubber anel1 to 10 mg of resins in a gJ-m1 yolumC For
bull
bull
bull
comparative ptuposes the leslllts arc also calculated on the basis oJvershycentage rubber OL tltsills in 02 gllI of tissul As WOlllL be expcet(d the error increases sOIlHgthlf for 1(lali nmiddotly low COlHell t1llf iOlls oj rllbbeL or resins The curves in figure 1(j s1l0 that ill til(gt Illlge Ol to 10 pCrshyeent of lubber the elTOI rangts Jroll1 abollt Ll to II) ]IlC(lIt abo(~ this mlllc tIlt (ITOl d(((ts(s to (ollsidlItbly ltmiddotss (han 1 1lICPllt of tlH mllollnt ltl((Lmill(d Hil1lilally in tlH (lISl of l(sins analysis (fig 10) the ltLTor is (onsit1eIubly INS than 1 PlLllnt ill (he lallgp of 11 t~) ~() penPII t
In nil ([lSl of lllhblI alld (sins lx(Inltpd tIOIl1 (issups Ol addcltl to tisslle lxtlads (s(( tabhmiddots (i H) illyolillg ll01P o(lllntiolls the eLI01
is hig]wl thun that indilHtld in figllll ((j Im pUIl Ill )])p I tllllllsins solutlOII
COlllUCIIOXFOH IXSOLl-IlLl~ Ilgsqgt(Jg
111 th( Jllo(pdulP ollllillPd 011 paw I till illsolllhll isSII Ipidll( tflpl (xttlw(ioll is (Ptill tlw lIask l(lll till xtlct i l1wdp up to yoltlllH It is not rOllPllipnt (0 IPt()PI qWlIltitati(Ir III(lw[olH a 11(1 pllooll extlnlfs of guuyull I is-lll alll thl1l main t11l111 up (0 YOIUllllmiddot bpCaUHI sllch all additiollal stltp wottld]) tillll-C(JllS11ll1illg Th( Iogiea nll(gtIshynntin is to mnkp tltl lXtlUCt Llld Ipsidup lip to OllillH in till original flask andi llPSStllY 10 llwlno tl OIIpdioll wlHIl (allIlnting [hc llshy
Hults f(JI [hl oll111lC displupd hy till ins()lllbh llsidll( III it l)picat (IXpednHllt (ollsisting of Jhp lppJiea(iolls if was Iollnd llftt at ~iiO ( 02 gill 01 Iuhhll pillS IPill-fl(( lisslI(gt (lollpdll fot llwistUlC ou basis of dlyillp ut lOW 101 ) llOlll-j (lbp(ld only t~ llllUll voiul11P of OOk7D~- OO(lOO(i Ill of lllthyl bolnl(yl 1lIOll( (lplhlli(al-t(Tnltle sp gl () Ii I ll(Hli (j at ~)) -gtitllP tl1(gt 1It101111( () r t is-lIl xt Iadld j sl1lall til( PlIOI dul to Ill(gt insoll1blp Ip~idll is slllall III [0111 ill( wOtk it (all lJp diIpgal(ll(l
]hcon~lIY OF HllIllgl AiO HESIS AIH)gl) TO EXTlIACI OP
GlYlLE TISSlg
Tnl)ll G L(IHpslntillp (ypi(nl llld(~ SllOS (hat all a plngl of HIOK PlI((nt ot lltl pltl( Ilhl)(l acldpd to tllP Itll h iolJut1 InmiddottcJllP xhnet
of guayulp tiSI1( WllS 1l((PllIl Tlli nllintioll flOlll (olllplpU I((OYshy
PIY i within flll pxp(IiIlHuttllIIOI ~illli]llly fnbll Ii llows thn 1111 llYlIUgl of 1O(1~ ])(I(Pllt of gllllYllII 1(-i1l- add(d to II( (pllosol( (xshytrae of IUllY]l t i~HI Is 1l(oPIPI
THl~ (~ Hf (Off Ill of 1111)( J OJ I~il~ lItfI(( In ~(JI1IJk~ Ilf (111 [lI1Il fI2 lIII
0 tlUfllllit i~~I1
Instrument
---- ----~---- bull shy 1(1
Colemun ruono~ltrOUlllt()r 2t) II sJl~ctroJlhOL()lIIeter with 2tJ I iflllllI wnclength Fetting 21 II nntl 0-1111 WU HI hUJl(L _ L U
Ill 7Evolyn photo~lcclrie (olor JU [ imctcr with iO-llIl filler IV (I
H1 0 t I I
llImiddot lUn WII 1011 HIO Wn mil lUulon
10 JIg1111 IUI ml lUl anh Io aLn 111)_I ) III li lU It 2) deg wn2SU DD
Irl JIll II IIr II US II
1110(1 lULa lUI IlK) IJ WU
I( llI Htl tNI 1(111 2tlNI HI 0 221) lllil t2S 0 1~ 10 1~13
In (I 2117 I
10U 1l(J ~ 4 _H_j ___
9middotJIlJ5 10115 10 00 lUU5 flUU 4li (tl03 9(11)
leIlKl 1l~)5 lOOU l1KIr JOIS un 003 OIl Ii
34 lECHNlCAL BULLErIN 920 U S DEPT OF AGRICULlURE
COMPARISON OF PHOTOMETRIC A1D MODJIoIED SPENCE-CALDWfLL METHODS OF RUBBER ANALYSIS
Guayule samples were analyzed by the photQ111etIic method and by bull the modified Spenc(gt-Cnldwell mcthod The values in table 7 represhyselltativ(I of typical results indieate It -atisfactory dcglpe of conformshyjty between the two methods in thl range of tiSSlHH with llHHC than OJ) percent of rubbtImiddot On the bnsis of the amounts determimd the results in this runge for the plmiddotts(nt lIlcthod ayernge apploxinHltely j percent highcr
~LAIII~ 7-(oIllJl(i~on of lltlllrIic (IIri mOtllinl SJl(II(r-(ulri-wall IIIrtlwrl~ of rlrrlIIillillfl 11)1)(1 COIIrll of UI(III
1 Flowers frllm amiddotmonth-oltl nursery plants
YAIIIATJO- OF SIli(LE DETEnt1NATIONS Fnoll TnEIIllIEAN
Rllbbel (Uall8i8-Thc plcCision of thc pLcsent method when gunyule tissues Hr( nnnlyz((1 for rubber may be j udg(d flom I Ill datil presentcd in table H TIl(se dahl -how that thl pplCPlltag( uriation of single determinatiom from nwan yullles with low standllrd enolS ranges from less than 1 to 4 p(gtrlent
R(8in~ wWlsi-r-s lndi(a((1 011 page ~j he INntlts s((uled hy the present phoolllttric nsins llHt hod are not tliltly (olllpalable with those of the grtLVimetri( ncetol1l-cxtlt1(tioll II1etho(l Thjs made it necesSllry to selc(t another lalibllltion staudud-tlll Ipsinous exullate from gullyule shrub-thut gies relatively COllstlllt photometric readshyings (table 5) The resin (olltents of guayule roots branchcs or leavcs usually ran(~e from about) to 1-1middot pelcellt The ple(ision of the present methotf WhCll gUHyule thslllS lIe analyzed for reins may be judged from the datalHmiddotpscllted ill table 9 1h(se data show that the p(lcelltage variatiun of sillgle lhmiddott(Lminntions iLO11 meun ynlnes with low standard NTOrs rangcs from about 05 to 4 percent
bull
bull
bull
bull
bull
RAPID PHOTOMETHIC DElEruIINAlION OJ RUBBEH AND HESINS 35
IAIILE 8-luriation inclieute rubller (mallSM of [1wIIle tissue bll thc 1111O0Illclc metwII
Vnrlntlon~Ilbher I (rom mean
ierCtnl Percelll ~OU -22 ~ 25 +27 ~ 20 +18 ~UO -22---------1_______ 51110 0G6 bullbullbullbullbullbull _bullbull
10 ro ----=ii41075 -01 1000 +11 1010 +13
rlln HI itil 1l9~ 1_ ___ =-~~~
115511 ~ US -111 III II 1575 -13 115 b tiS -I a 111 h WlU +22IIM-(middot bull 11K -1Ja Illi c 1000 +03 1J5H1 W +l)7 ll1imiddot tl 1575 -13
Mcnn 15951 131
1102-11 21fJ() +21l102-h _ ~~)SO -17 1102-c bullbull 21CO +21n02middotd ~OIiO -26
2 r~plusmn Il~ 21151 261 I -~-------bull---__ _~~_~______l-___--_
1 lhe$ 1111($ I1n (or SlIlIIllltS Stpnnltplr PHrilClld IIrtlrdlng 10 1hr prollIlIlr( OIiIIiIl(o(I on Imgt$ 4 to IC ~tcond nUlI1 hlr r(J)[ltnts stl1ndnnl llrrot of tilt 1I1(1111
1_1l1~ n-J(lri(iot in relli(Upound rpoundsins (lllalIsfs of VIOJII( lixsue b1 the lhomillric lII(lloli
-- ---~--- - __-------- shybull I I I I Varlgttton
_________~___ ~~lu_n_Jl_Q_~~~_____ ______I__~_o~S_J frOID lDean
Percent Percentgt458-1 ~65 +41IWtl-li 130 -a2Hli8c aliO +26S41i8-d bull 130 -32
1(-011 34I10Olifgt __ bullbull __ ~--====
li-9~2n 881) -06 li-9~2-b Si5 o ~HH2middot(middot S i5 -6$-H2middotd 000 +1
8851 054
O i5 +6 9 i5 +6 950 -20 U75 +6
H-liG3o-n bull -1 n-li6~b bull __ _ -IH-IWH +4H-l61511 bull -1
1tmiddottlU
62~-lI __ 62~-b ij24-( bull OH-Ji
(-Ull
I rll(St oluls nre tor separately ~xlrflCled SllllllllCS IlctOrdlug lO procedure outllned ou pages 4 to 10 i Secoud number r~prtgeulS stulldMd error of lIe menn
36 TECHNICAL BULLETIN 920 t ~ DEPT OF A(]RICCLTCRE
ReUUER A~ALYSrS I~ CRCOE-RcuUER PROOCCTS
Sew rapid photometric m(lthod~fol the ddellllinttion of rubber and reii Hi ill uaYllp ti--ut htp lllell pIPHnl pd oil pag( ~l to In A brief H1111111tlY of It similar rnpid llHthod fm 1I1hb~rllnltlysis of u1lulcanizNl tlIldp lubbll pl(Hlmtlt whielt i~ bn-(tldo on the prill o
ciples dehtilcd tlllLe follows Duplltate nt-gm sllmph of the finely cliyiliNl IlInttlitiup wlirllll out [~ei-()l (all hl lIf((tinmiddotjv INd to lt1iyidl till alllpl) TIll kltolll-olubll portion of till )111(11( tlrc di-olved a- indh-Htpd fot thmiddot lllnkill~ of -tlllHlunlluhhll olutiou Oil Pt 1II hut tIl IUlIp Hn lIn l-fplImiddotd 10 lHI-ml rolllllltti( fln-k antil1ltld(lup to Olllll1l The bnlulUp or till JllO(ldllll i- thatutlilllll on paWs -1- 1 IHI Ii 111( 1(111 1- nIP IXPIP--pd nil til IHi or Iw oligiJla w(lullt of I Ill (I11l1p-I1l11Ilt1 1)(0(11(1
Hupitl PlllimiPJojgtiWllllllllh llIltllOd~ fOJ Ihl llPtlmiddotminntion of ImiddotUlJbll tlnd 1(-illo- ill -111111 Illllph of gutlYllll tiUl IIll dl-eli)ed 111() IlltlY d~o Ill nltlI1lld fOl III Iwl Illhlwl- and l~iJlmiddotb(lLiJlg plant TIllt l[Olllhup hns nlo b(l1l ntuptpl fot IIH lltlIll1illtltioll of lllhbpl ill 11lHhrublwl Pl(Jdlld~ HIIl 1111 hI ndaptld JoJ IIll ann lysis of ynt1J(gt( ic lllbbl[- The llllthmb HIP 1gtn(11 fill tIll fol1owill plimiph- III Grinding
tIll PIOPlly driPl t i~lIl 01 Ul tillg tIll pnHhHt to tll l((lllilllllh~lel of filWlH-- til plllllit qIHlIllilnth( lXIIHtioll 01 IIlbhlI 01 1(--IJl- () llsing oXWllutld olnuh (kttoJls IIt(talp and() fllltil for LIbbel and IH(ltIlIlyptIJllIllIoolYlnJld-o flJllh 101 niJlsl with t(lathelr high IlPililig points 111 to n C) l]olle or in mixt tIll thllt Pll mit tlll rnphllxututioll of luhll(l OJ [middot(ill ill ~() to (l mi1lutp It r(latiwly high 1lllIllllltlltP Ill to 1~11 ) l) lllllipitntillu till luhblI OL Imiddot(ill frolll aliquot () f till oltn ion I IlIlllI-i () f Hlltabhmiddot pl(~(i]litallt (willifhmiddotd lthmwl fOl IIlhlHI Hild llitlifild lllr fOJ JP-illl t~) IIlHkillphotollllliilPIIIIiIlof PlllPlltal of liht tLaIlS mittUl(P lIftlI IlIlbll (II Il in PIlipitalioll 11 II WI( Iplllh thnt (limiJlall till PIIOl dill 10 xtralllOlh (0101 (till dptl1minntinll Iph jill 011 tIll dtwlopllIlJIl of H HIli rOI1ll tlllbidity 111 hpl than I (olot rI
jJlIlpOP-ofallnlyi-I ( p(lllil1thb IIllijOI1ll turbidity or 1llt[lIinmiddotd d(ltl of jgtIp(ii(JlI l)~ lIltlkillU tIl plllltollllmiddottri( ntdillU al tandinu tiJlH~ (dlllilll wlli(h IhlllH(lill-- IP 1llutinmiddotly tnhll) t1ll1t an hlsl~1 oil the (oJlItlIlllItion of IIlhlHI Ill I(ill (lIPIipitat((L
TIll -I(p ill till jll()(Plhul HIP 1-- follOylt (1) 1l~UIIL uJ1lplls of thwl UJfJlllHl (II tliddl(l HUt dlipd 11Illtplial an lXIllltel with11 Ill of till nlnll ill t (oU tlllltIPlll[gtPImiddotatlup oil Iath at 11 Cbull fol 11 minutl I) iIP1lIin(middot(lohd til( (XUtllhllll Jltldl lip to It middotml ynlmlll til( (nlifild by (Illlifllgiuu HlId thlPl IlI nliql1ot of tIl (IalioPlllxUlltl nll Uillltlmiddotll(t to l-llll OIlIIlIllril fiuk- (1) For a trial Ilnditlg 0111 III tlll j liJmiddot~t IllHII IIjI to Ohlllll with lilt Pll shy(ilitnnl a 1(11 it 111 (Dod fill llli lIut ( ptotoJIIltlil IPtlllillg-- of pllllntnl or liuht tlUtllIlillal(I oil n (lpel OphotnJlllllI at rase hng-tlt (If 11 llJ Ill Ol It lollllil1lPtImiddott lloyidld with tIll P10]11 I 1110110shy
Ihlolllltt hmiddot Ii1llI Olllhi lIatioll for -1IpItillg UJlproXilll1l tply Wtl P ]Plwth )0 mp are HHlltk TIll Illldillg lliJtaillld fol tIlt 4-milutl tliall(~ll-
bull
bull
bull
RAPID PHOTO~IETRIC DETERIINATIOX OF R(BBER AXD RESINS 37
ing are referred to a table of equhmiddottllut~ previously p1(pa1elt1 on the
bull basis of 4-minute reac1inJ~ for tilE nmge of lot1telltlatiol1- of rubber or resins to bE elHOlll1t(led tmd gidn thtmiddot -tnnlillfr tillIP fill rUbbEt or resins aiter prE(ipitlltiol1 lwfolE photoIllNliI j(tltlill1 un IUade The r(middotnmining dllplllatt aliquot lll then HHllil up te ol1l1Jle and lpoundadillg ale marle ut the -tandillfr tiUlE iudklltll ill rhl tall1lmiddot for the final r(adillg~ -1) 111( milli1lnm or p(tCPlltllt- of lllhbpL (II 1(-in pr(s(nt are rpadholU a prlpan(l table of lquiltlput for tlll photoshymetric readings h1~l(l ill pnell e1-E on pxpPlilmlItal lhln 1111(1 u-ing as stimtlltlds pure luhbll in 1l1bbtl milllYb aIHI guaYllh ll-ill- lxIHlatt~ in resins detNIl1111lttion I
LlTERATlRE CLTED
(1) lUnSbull 1fl36 THE mURMIXTIOS IIF IOTA RE I III OOl THER llT~II
F1 bullrol IlY U(T1l0fll UfSlfi ~rrnrl r flm lt1 KEYS TI Bill Chern 114 44J-l59 illns
t1 ~ICPHHlObullbull T 1J3bull~ lUTHOO roa THE PtRInCAnu Or a(lIUl IRrIlHU It of TIn
PLRIHEU Htllllflt [ i Bill lallllall 111 Rmiddot 711middotj iIlus
I ) RHBERG P B Ul5 A METHIlO Or ~u(ronrll-nl Hi tIII rUIl[1 f71 ii illlI
bull 14 Hoss W flbull and HARDESTY J O
llH IR1ltDII Of HfITilIZfmiddotR DllIJS ltt 1 Yl fll Off gI bern JIIIlI i ~middotmiddotlf IIl
101 SPEltCE D nnd CuoWELr ~I L 1933 DETER~n-ATIOo OF RtBBER Ii nrllllpoundRBfR Iusr 1uI II1 amI
Em~ifl cttIliIa~~ r Ell i 71middot7i l11 (HI WALTER E D
1U44 ISO~nlS OF PRTlltSrr 1trHpoundV bull l UI n W lHHt (Tnmiddot 1ETS FROM GiYI l~iIl lItr Clttrn SII J UI titJ middotn9--C1 ilIu
17 J YOEbullbullr H lO~( roLORIlETRT 771 IPmiddot nl -W Yurk f H Plrwptric hmica
naly-II rimttry lUll XphHHlnmiddot~ y 1 1
11
HI) ~ fPHELolzTRf 57 111bull Lin xw Yk t H lt PhmeHt CblUlmiddot ila AnaiY~l~-(H lithrry and XIhmiddotILpfIY Y wirh enomiddot rrJlllrjr hy H KtlJnJU11 I
t~1I --- and ~ARVER L 1f41 nlua-w ~in L liLhr IS IP ll~ XIW Yrk
bull For-sale by th~ ~a~fr1nt~nf1ent Dt~c~~ogtnts-~ s t1i rArnn~ut Pn~~~ tJffieshy
Washington 5 D C bull Pl lU ~nts
RAPID PHOTOlJElRIC DELEHlllNAllON Cn HUBBER AND H1~SINS 33
10 mg of rubber anel1 to 10 mg of resins in a gJ-m1 yolumC For
bull
bull
bull
comparative ptuposes the leslllts arc also calculated on the basis oJvershycentage rubber OL tltsills in 02 gllI of tissul As WOlllL be expcet(d the error increases sOIlHgthlf for 1(lali nmiddotly low COlHell t1llf iOlls oj rllbbeL or resins The curves in figure 1(j s1l0 that ill til(gt Illlge Ol to 10 pCrshyeent of lubber the elTOI rangts Jroll1 abollt Ll to II) ]IlC(lIt abo(~ this mlllc tIlt (ITOl d(((ts(s to (ollsidlItbly ltmiddotss (han 1 1lICPllt of tlH mllollnt ltl((Lmill(d Hil1lilally in tlH (lISl of l(sins analysis (fig 10) the ltLTor is (onsit1eIubly INS than 1 PlLllnt ill (he lallgp of 11 t~) ~() penPII t
In nil ([lSl of lllhblI alld (sins lx(Inltpd tIOIl1 (issups Ol addcltl to tisslle lxtlads (s(( tabhmiddots (i H) illyolillg ll01P o(lllntiolls the eLI01
is hig]wl thun that indilHtld in figllll ((j Im pUIl Ill )])p I tllllllsins solutlOII
COlllUCIIOXFOH IXSOLl-IlLl~ Ilgsqgt(Jg
111 th( Jllo(pdulP ollllillPd 011 paw I till illsolllhll isSII Ipidll( tflpl (xttlw(ioll is (Ptill tlw lIask l(lll till xtlct i l1wdp up to yoltlllH It is not rOllPllipnt (0 IPt()PI qWlIltitati(Ir III(lw[olH a 11(1 pllooll extlnlfs of guuyull I is-lll alll thl1l main t11l111 up (0 YOIUllllmiddot bpCaUHI sllch all additiollal stltp wottld]) tillll-C(JllS11ll1illg Th( Iogiea nll(gtIshynntin is to mnkp tltl lXtlUCt Llld Ipsidup lip to OllillH in till original flask andi llPSStllY 10 llwlno tl OIIpdioll wlHIl (allIlnting [hc llshy
Hults f(JI [hl oll111lC displupd hy till ins()lllbh llsidll( III it l)picat (IXpednHllt (ollsisting of Jhp lppJiea(iolls if was Iollnd llftt at ~iiO ( 02 gill 01 Iuhhll pillS IPill-fl(( lisslI(gt (lollpdll fot llwistUlC ou basis of dlyillp ut lOW 101 ) llOlll-j (lbp(ld only t~ llllUll voiul11P of OOk7D~- OO(lOO(i Ill of lllthyl bolnl(yl 1lIOll( (lplhlli(al-t(Tnltle sp gl () Ii I ll(Hli (j at ~)) -gtitllP tl1(gt 1It101111( () r t is-lIl xt Iadld j sl1lall til( PlIOI dul to Ill(gt insoll1blp Ip~idll is slllall III [0111 ill( wOtk it (all lJp diIpgal(ll(l
]hcon~lIY OF HllIllgl AiO HESIS AIH)gl) TO EXTlIACI OP
GlYlLE TISSlg
Tnl)ll G L(IHpslntillp (ypi(nl llld(~ SllOS (hat all a plngl of HIOK PlI((nt ot lltl pltl( Ilhl)(l acldpd to tllP Itll h iolJut1 InmiddottcJllP xhnet
of guayulp tiSI1( WllS 1l((PllIl Tlli nllintioll flOlll (olllplpU I((OYshy
PIY i within flll pxp(IiIlHuttllIIOI ~illli]llly fnbll Ii llows thn 1111 llYlIUgl of 1O(1~ ])(I(Pllt of gllllYllII 1(-i1l- add(d to II( (pllosol( (xshytrae of IUllY]l t i~HI Is 1l(oPIPI
THl~ (~ Hf (Off Ill of 1111)( J OJ I~il~ lItfI(( In ~(JI1IJk~ Ilf (111 [lI1Il fI2 lIII
0 tlUfllllit i~~I1
Instrument
---- ----~---- bull shy 1(1
Colemun ruono~ltrOUlllt()r 2t) II sJl~ctroJlhOL()lIIeter with 2tJ I iflllllI wnclength Fetting 21 II nntl 0-1111 WU HI hUJl(L _ L U
Ill 7Evolyn photo~lcclrie (olor JU [ imctcr with iO-llIl filler IV (I
H1 0 t I I
llImiddot lUn WII 1011 HIO Wn mil lUulon
10 JIg1111 IUI ml lUl anh Io aLn 111)_I ) III li lU It 2) deg wn2SU DD
Irl JIll II IIr II US II
1110(1 lULa lUI IlK) IJ WU
I( llI Htl tNI 1(111 2tlNI HI 0 221) lllil t2S 0 1~ 10 1~13
In (I 2117 I
10U 1l(J ~ 4 _H_j ___
9middotJIlJ5 10115 10 00 lUU5 flUU 4li (tl03 9(11)
leIlKl 1l~)5 lOOU l1KIr JOIS un 003 OIl Ii
34 lECHNlCAL BULLErIN 920 U S DEPT OF AGRICULlURE
COMPARISON OF PHOTOMETRIC A1D MODJIoIED SPENCE-CALDWfLL METHODS OF RUBBER ANALYSIS
Guayule samples were analyzed by the photQ111etIic method and by bull the modified Spenc(gt-Cnldwell mcthod The values in table 7 represhyselltativ(I of typical results indieate It -atisfactory dcglpe of conformshyjty between the two methods in thl range of tiSSlHH with llHHC than OJ) percent of rubbtImiddot On the bnsis of the amounts determimd the results in this runge for the plmiddotts(nt lIlcthod ayernge apploxinHltely j percent highcr
~LAIII~ 7-(oIllJl(i~on of lltlllrIic (IIri mOtllinl SJl(II(r-(ulri-wall IIIrtlwrl~ of rlrrlIIillillfl 11)1)(1 COIIrll of UI(III
1 Flowers frllm amiddotmonth-oltl nursery plants
YAIIIATJO- OF SIli(LE DETEnt1NATIONS Fnoll TnEIIllIEAN
Rllbbel (Uall8i8-Thc plcCision of thc pLcsent method when gunyule tissues Hr( nnnlyz((1 for rubber may be j udg(d flom I Ill datil presentcd in table H TIl(se dahl -how that thl pplCPlltag( uriation of single determinatiom from nwan yullles with low standllrd enolS ranges from less than 1 to 4 p(gtrlent
R(8in~ wWlsi-r-s lndi(a((1 011 page ~j he INntlts s((uled hy the present phoolllttric nsins llHt hod are not tliltly (olllpalable with those of the grtLVimetri( ncetol1l-cxtlt1(tioll II1etho(l Thjs made it necesSllry to selc(t another lalibllltion staudud-tlll Ipsinous exullate from gullyule shrub-thut gies relatively COllstlllt photometric readshyings (table 5) The resin (olltents of guayule roots branchcs or leavcs usually ran(~e from about) to 1-1middot pelcellt The ple(ision of the present methotf WhCll gUHyule thslllS lIe analyzed for reins may be judged from the datalHmiddotpscllted ill table 9 1h(se data show that the p(lcelltage variatiun of sillgle lhmiddott(Lminntions iLO11 meun ynlnes with low standard NTOrs rangcs from about 05 to 4 percent
bull
bull
bull
bull
bull
RAPID PHOTOMETHIC DElEruIINAlION OJ RUBBEH AND HESINS 35
IAIILE 8-luriation inclieute rubller (mallSM of [1wIIle tissue bll thc 1111O0Illclc metwII
Vnrlntlon~Ilbher I (rom mean
ierCtnl Percelll ~OU -22 ~ 25 +27 ~ 20 +18 ~UO -22---------1_______ 51110 0G6 bullbullbullbullbullbull _bullbull
10 ro ----=ii41075 -01 1000 +11 1010 +13
rlln HI itil 1l9~ 1_ ___ =-~~~
115511 ~ US -111 III II 1575 -13 115 b tiS -I a 111 h WlU +22IIM-(middot bull 11K -1Ja Illi c 1000 +03 1J5H1 W +l)7 ll1imiddot tl 1575 -13
Mcnn 15951 131
1102-11 21fJ() +21l102-h _ ~~)SO -17 1102-c bullbull 21CO +21n02middotd ~OIiO -26
2 r~plusmn Il~ 21151 261 I -~-------bull---__ _~~_~______l-___--_
1 lhe$ 1111($ I1n (or SlIlIIllltS Stpnnltplr PHrilClld IIrtlrdlng 10 1hr prollIlIlr( OIiIIiIl(o(I on Imgt$ 4 to IC ~tcond nUlI1 hlr r(J)[ltnts stl1ndnnl llrrot of tilt 1I1(1111
1_1l1~ n-J(lri(iot in relli(Upound rpoundsins (lllalIsfs of VIOJII( lixsue b1 the lhomillric lII(lloli
-- ---~--- - __-------- shybull I I I I Varlgttton
_________~___ ~~lu_n_Jl_Q_~~~_____ ______I__~_o~S_J frOID lDean
Percent Percentgt458-1 ~65 +41IWtl-li 130 -a2Hli8c aliO +26S41i8-d bull 130 -32
1(-011 34I10Olifgt __ bullbull __ ~--====
li-9~2n 881) -06 li-9~2-b Si5 o ~HH2middot(middot S i5 -6$-H2middotd 000 +1
8851 054
O i5 +6 9 i5 +6 950 -20 U75 +6
H-liG3o-n bull -1 n-li6~b bull __ _ -IH-IWH +4H-l61511 bull -1
1tmiddottlU
62~-lI __ 62~-b ij24-( bull OH-Ji
(-Ull
I rll(St oluls nre tor separately ~xlrflCled SllllllllCS IlctOrdlug lO procedure outllned ou pages 4 to 10 i Secoud number r~prtgeulS stulldMd error of lIe menn
36 TECHNICAL BULLETIN 920 t ~ DEPT OF A(]RICCLTCRE
ReUUER A~ALYSrS I~ CRCOE-RcuUER PROOCCTS
Sew rapid photometric m(lthod~fol the ddellllinttion of rubber and reii Hi ill uaYllp ti--ut htp lllell pIPHnl pd oil pag( ~l to In A brief H1111111tlY of It similar rnpid llHthod fm 1I1hb~rllnltlysis of u1lulcanizNl tlIldp lubbll pl(Hlmtlt whielt i~ bn-(tldo on the prill o
ciples dehtilcd tlllLe follows Duplltate nt-gm sllmph of the finely cliyiliNl IlInttlitiup wlirllll out [~ei-()l (all hl lIf((tinmiddotjv INd to lt1iyidl till alllpl) TIll kltolll-olubll portion of till )111(11( tlrc di-olved a- indh-Htpd fot thmiddot lllnkill~ of -tlllHlunlluhhll olutiou Oil Pt 1II hut tIl IUlIp Hn lIn l-fplImiddotd 10 lHI-ml rolllllltti( fln-k antil1ltld(lup to Olllll1l The bnlulUp or till JllO(ldllll i- thatutlilllll on paWs -1- 1 IHI Ii 111( 1(111 1- nIP IXPIP--pd nil til IHi or Iw oligiJla w(lullt of I Ill (I11l1p-I1l11Ilt1 1)(0(11(1
Hupitl PlllimiPJojgtiWllllllllh llIltllOd~ fOJ Ihl llPtlmiddotminntion of ImiddotUlJbll tlnd 1(-illo- ill -111111 Illllph of gutlYllll tiUl IIll dl-eli)ed 111() IlltlY d~o Ill nltlI1lld fOl III Iwl Illhlwl- and l~iJlmiddotb(lLiJlg plant TIllt l[Olllhup hns nlo b(l1l ntuptpl fot IIH lltlIll1illtltioll of lllhbpl ill 11lHhrublwl Pl(Jdlld~ HIIl 1111 hI ndaptld JoJ IIll ann lysis of ynt1J(gt( ic lllbbl[- The llllthmb HIP 1gtn(11 fill tIll fol1owill plimiph- III Grinding
tIll PIOPlly driPl t i~lIl 01 Ul tillg tIll pnHhHt to tll l((lllilllllh~lel of filWlH-- til plllllit qIHlIllilnth( lXIIHtioll 01 IIlbhlI 01 1(--IJl- () llsing oXWllutld olnuh (kttoJls IIt(talp and() fllltil for LIbbel and IH(ltIlIlyptIJllIllIoolYlnJld-o flJllh 101 niJlsl with t(lathelr high IlPililig points 111 to n C) l]olle or in mixt tIll thllt Pll mit tlll rnphllxututioll of luhll(l OJ [middot(ill ill ~() to (l mi1lutp It r(latiwly high 1lllIllllltlltP Ill to 1~11 ) l) lllllipitntillu till luhblI OL Imiddot(ill frolll aliquot () f till oltn ion I IlIlllI-i () f Hlltabhmiddot pl(~(i]litallt (willifhmiddotd lthmwl fOl IIlhlHI Hild llitlifild lllr fOJ JP-illl t~) IIlHkillphotollllliilPIIIIiIlof PlllPlltal of liht tLaIlS mittUl(P lIftlI IlIlbll (II Il in PIlipitalioll 11 II WI( Iplllh thnt (limiJlall till PIIOl dill 10 xtralllOlh (0101 (till dptl1minntinll Iph jill 011 tIll dtwlopllIlJIl of H HIli rOI1ll tlllbidity 111 hpl than I (olot rI
jJlIlpOP-ofallnlyi-I ( p(lllil1thb IIllijOI1ll turbidity or 1llt[lIinmiddotd d(ltl of jgtIp(ii(JlI l)~ lIltlkillU tIl plllltollllmiddottri( ntdillU al tandinu tiJlH~ (dlllilll wlli(h IhlllH(lill-- IP 1llutinmiddotly tnhll) t1ll1t an hlsl~1 oil the (oJlItlIlllItion of IIlhlHI Ill I(ill (lIPIipitat((L
TIll -I(p ill till jll()(Plhul HIP 1-- follOylt (1) 1l~UIIL uJ1lplls of thwl UJfJlllHl (II tliddl(l HUt dlipd 11Illtplial an lXIllltel with11 Ill of till nlnll ill t (oU tlllltIPlll[gtPImiddotatlup oil Iath at 11 Cbull fol 11 minutl I) iIP1lIin(middot(lohd til( (XUtllhllll Jltldl lip to It middotml ynlmlll til( (nlifild by (Illlifllgiuu HlId thlPl IlI nliql1ot of tIl (IalioPlllxUlltl nll Uillltlmiddotll(t to l-llll OIlIIlIllril fiuk- (1) For a trial Ilnditlg 0111 III tlll j liJmiddot~t IllHII IIjI to Ohlllll with lilt Pll shy(ilitnnl a 1(11 it 111 (Dod fill llli lIut ( ptotoJIIltlil IPtlllillg-- of pllllntnl or liuht tlUtllIlillal(I oil n (lpel OphotnJlllllI at rase hng-tlt (If 11 llJ Ill Ol It lollllil1lPtImiddott lloyidld with tIll P10]11 I 1110110shy
Ihlolllltt hmiddot Ii1llI Olllhi lIatioll for -1IpItillg UJlproXilll1l tply Wtl P ]Plwth )0 mp are HHlltk TIll Illldillg lliJtaillld fol tIlt 4-milutl tliall(~ll-
bull
bull
bull
RAPID PHOTO~IETRIC DETERIINATIOX OF R(BBER AXD RESINS 37
ing are referred to a table of equhmiddottllut~ previously p1(pa1elt1 on the
bull basis of 4-minute reac1inJ~ for tilE nmge of lot1telltlatiol1- of rubber or resins to bE elHOlll1t(led tmd gidn thtmiddot -tnnlillfr tillIP fill rUbbEt or resins aiter prE(ipitlltiol1 lwfolE photoIllNliI j(tltlill1 un IUade The r(middotnmining dllplllatt aliquot lll then HHllil up te ol1l1Jle and lpoundadillg ale marle ut the -tandillfr tiUlE iudklltll ill rhl tall1lmiddot for the final r(adillg~ -1) 111( milli1lnm or p(tCPlltllt- of lllhbpL (II 1(-in pr(s(nt are rpadholU a prlpan(l table of lquiltlput for tlll photoshymetric readings h1~l(l ill pnell e1-E on pxpPlilmlItal lhln 1111(1 u-ing as stimtlltlds pure luhbll in 1l1bbtl milllYb aIHI guaYllh ll-ill- lxIHlatt~ in resins detNIl1111lttion I
LlTERATlRE CLTED
(1) lUnSbull 1fl36 THE mURMIXTIOS IIF IOTA RE I III OOl THER llT~II
F1 bullrol IlY U(T1l0fll UfSlfi ~rrnrl r flm lt1 KEYS TI Bill Chern 114 44J-l59 illns
t1 ~ICPHHlObullbull T 1J3bull~ lUTHOO roa THE PtRInCAnu Or a(lIUl IRrIlHU It of TIn
PLRIHEU Htllllflt [ i Bill lallllall 111 Rmiddot 711middotj iIlus
I ) RHBERG P B Ul5 A METHIlO Or ~u(ronrll-nl Hi tIII rUIl[1 f71 ii illlI
bull 14 Hoss W flbull and HARDESTY J O
llH IR1ltDII Of HfITilIZfmiddotR DllIJS ltt 1 Yl fll Off gI bern JIIIlI i ~middotmiddotlf IIl
101 SPEltCE D nnd CuoWELr ~I L 1933 DETER~n-ATIOo OF RtBBER Ii nrllllpoundRBfR Iusr 1uI II1 amI
Em~ifl cttIliIa~~ r Ell i 71middot7i l11 (HI WALTER E D
1U44 ISO~nlS OF PRTlltSrr 1trHpoundV bull l UI n W lHHt (Tnmiddot 1ETS FROM GiYI l~iIl lItr Clttrn SII J UI titJ middotn9--C1 ilIu
17 J YOEbullbullr H lO~( roLORIlETRT 771 IPmiddot nl -W Yurk f H Plrwptric hmica
naly-II rimttry lUll XphHHlnmiddot~ y 1 1
11
HI) ~ fPHELolzTRf 57 111bull Lin xw Yk t H lt PhmeHt CblUlmiddot ila AnaiY~l~-(H lithrry and XIhmiddotILpfIY Y wirh enomiddot rrJlllrjr hy H KtlJnJU11 I
t~1I --- and ~ARVER L 1f41 nlua-w ~in L liLhr IS IP ll~ XIW Yrk
bull For-sale by th~ ~a~fr1nt~nf1ent Dt~c~~ogtnts-~ s t1i rArnn~ut Pn~~~ tJffieshy
Washington 5 D C bull Pl lU ~nts
34 lECHNlCAL BULLErIN 920 U S DEPT OF AGRICULlURE
COMPARISON OF PHOTOMETRIC A1D MODJIoIED SPENCE-CALDWfLL METHODS OF RUBBER ANALYSIS
Guayule samples were analyzed by the photQ111etIic method and by bull the modified Spenc(gt-Cnldwell mcthod The values in table 7 represhyselltativ(I of typical results indieate It -atisfactory dcglpe of conformshyjty between the two methods in thl range of tiSSlHH with llHHC than OJ) percent of rubbtImiddot On the bnsis of the amounts determimd the results in this runge for the plmiddotts(nt lIlcthod ayernge apploxinHltely j percent highcr
~LAIII~ 7-(oIllJl(i~on of lltlllrIic (IIri mOtllinl SJl(II(r-(ulri-wall IIIrtlwrl~ of rlrrlIIillillfl 11)1)(1 COIIrll of UI(III
1 Flowers frllm amiddotmonth-oltl nursery plants
YAIIIATJO- OF SIli(LE DETEnt1NATIONS Fnoll TnEIIllIEAN
Rllbbel (Uall8i8-Thc plcCision of thc pLcsent method when gunyule tissues Hr( nnnlyz((1 for rubber may be j udg(d flom I Ill datil presentcd in table H TIl(se dahl -how that thl pplCPlltag( uriation of single determinatiom from nwan yullles with low standllrd enolS ranges from less than 1 to 4 p(gtrlent
R(8in~ wWlsi-r-s lndi(a((1 011 page ~j he INntlts s((uled hy the present phoolllttric nsins llHt hod are not tliltly (olllpalable with those of the grtLVimetri( ncetol1l-cxtlt1(tioll II1etho(l Thjs made it necesSllry to selc(t another lalibllltion staudud-tlll Ipsinous exullate from gullyule shrub-thut gies relatively COllstlllt photometric readshyings (table 5) The resin (olltents of guayule roots branchcs or leavcs usually ran(~e from about) to 1-1middot pelcellt The ple(ision of the present methotf WhCll gUHyule thslllS lIe analyzed for reins may be judged from the datalHmiddotpscllted ill table 9 1h(se data show that the p(lcelltage variatiun of sillgle lhmiddott(Lminntions iLO11 meun ynlnes with low standard NTOrs rangcs from about 05 to 4 percent
bull
bull
bull
bull
bull
RAPID PHOTOMETHIC DElEruIINAlION OJ RUBBEH AND HESINS 35
IAIILE 8-luriation inclieute rubller (mallSM of [1wIIle tissue bll thc 1111O0Illclc metwII
Vnrlntlon~Ilbher I (rom mean
ierCtnl Percelll ~OU -22 ~ 25 +27 ~ 20 +18 ~UO -22---------1_______ 51110 0G6 bullbullbullbullbullbull _bullbull
10 ro ----=ii41075 -01 1000 +11 1010 +13
rlln HI itil 1l9~ 1_ ___ =-~~~
115511 ~ US -111 III II 1575 -13 115 b tiS -I a 111 h WlU +22IIM-(middot bull 11K -1Ja Illi c 1000 +03 1J5H1 W +l)7 ll1imiddot tl 1575 -13
Mcnn 15951 131
1102-11 21fJ() +21l102-h _ ~~)SO -17 1102-c bullbull 21CO +21n02middotd ~OIiO -26
2 r~plusmn Il~ 21151 261 I -~-------bull---__ _~~_~______l-___--_
1 lhe$ 1111($ I1n (or SlIlIIllltS Stpnnltplr PHrilClld IIrtlrdlng 10 1hr prollIlIlr( OIiIIiIl(o(I on Imgt$ 4 to IC ~tcond nUlI1 hlr r(J)[ltnts stl1ndnnl llrrot of tilt 1I1(1111
1_1l1~ n-J(lri(iot in relli(Upound rpoundsins (lllalIsfs of VIOJII( lixsue b1 the lhomillric lII(lloli
-- ---~--- - __-------- shybull I I I I Varlgttton
_________~___ ~~lu_n_Jl_Q_~~~_____ ______I__~_o~S_J frOID lDean
Percent Percentgt458-1 ~65 +41IWtl-li 130 -a2Hli8c aliO +26S41i8-d bull 130 -32
1(-011 34I10Olifgt __ bullbull __ ~--====
li-9~2n 881) -06 li-9~2-b Si5 o ~HH2middot(middot S i5 -6$-H2middotd 000 +1
8851 054
O i5 +6 9 i5 +6 950 -20 U75 +6
H-liG3o-n bull -1 n-li6~b bull __ _ -IH-IWH +4H-l61511 bull -1
1tmiddottlU
62~-lI __ 62~-b ij24-( bull OH-Ji
(-Ull
I rll(St oluls nre tor separately ~xlrflCled SllllllllCS IlctOrdlug lO procedure outllned ou pages 4 to 10 i Secoud number r~prtgeulS stulldMd error of lIe menn
36 TECHNICAL BULLETIN 920 t ~ DEPT OF A(]RICCLTCRE
ReUUER A~ALYSrS I~ CRCOE-RcuUER PROOCCTS
Sew rapid photometric m(lthod~fol the ddellllinttion of rubber and reii Hi ill uaYllp ti--ut htp lllell pIPHnl pd oil pag( ~l to In A brief H1111111tlY of It similar rnpid llHthod fm 1I1hb~rllnltlysis of u1lulcanizNl tlIldp lubbll pl(Hlmtlt whielt i~ bn-(tldo on the prill o
ciples dehtilcd tlllLe follows Duplltate nt-gm sllmph of the finely cliyiliNl IlInttlitiup wlirllll out [~ei-()l (all hl lIf((tinmiddotjv INd to lt1iyidl till alllpl) TIll kltolll-olubll portion of till )111(11( tlrc di-olved a- indh-Htpd fot thmiddot lllnkill~ of -tlllHlunlluhhll olutiou Oil Pt 1II hut tIl IUlIp Hn lIn l-fplImiddotd 10 lHI-ml rolllllltti( fln-k antil1ltld(lup to Olllll1l The bnlulUp or till JllO(ldllll i- thatutlilllll on paWs -1- 1 IHI Ii 111( 1(111 1- nIP IXPIP--pd nil til IHi or Iw oligiJla w(lullt of I Ill (I11l1p-I1l11Ilt1 1)(0(11(1
Hupitl PlllimiPJojgtiWllllllllh llIltllOd~ fOJ Ihl llPtlmiddotminntion of ImiddotUlJbll tlnd 1(-illo- ill -111111 Illllph of gutlYllll tiUl IIll dl-eli)ed 111() IlltlY d~o Ill nltlI1lld fOl III Iwl Illhlwl- and l~iJlmiddotb(lLiJlg plant TIllt l[Olllhup hns nlo b(l1l ntuptpl fot IIH lltlIll1illtltioll of lllhbpl ill 11lHhrublwl Pl(Jdlld~ HIIl 1111 hI ndaptld JoJ IIll ann lysis of ynt1J(gt( ic lllbbl[- The llllthmb HIP 1gtn(11 fill tIll fol1owill plimiph- III Grinding
tIll PIOPlly driPl t i~lIl 01 Ul tillg tIll pnHhHt to tll l((lllilllllh~lel of filWlH-- til plllllit qIHlIllilnth( lXIIHtioll 01 IIlbhlI 01 1(--IJl- () llsing oXWllutld olnuh (kttoJls IIt(talp and() fllltil for LIbbel and IH(ltIlIlyptIJllIllIoolYlnJld-o flJllh 101 niJlsl with t(lathelr high IlPililig points 111 to n C) l]olle or in mixt tIll thllt Pll mit tlll rnphllxututioll of luhll(l OJ [middot(ill ill ~() to (l mi1lutp It r(latiwly high 1lllIllllltlltP Ill to 1~11 ) l) lllllipitntillu till luhblI OL Imiddot(ill frolll aliquot () f till oltn ion I IlIlllI-i () f Hlltabhmiddot pl(~(i]litallt (willifhmiddotd lthmwl fOl IIlhlHI Hild llitlifild lllr fOJ JP-illl t~) IIlHkillphotollllliilPIIIIiIlof PlllPlltal of liht tLaIlS mittUl(P lIftlI IlIlbll (II Il in PIlipitalioll 11 II WI( Iplllh thnt (limiJlall till PIIOl dill 10 xtralllOlh (0101 (till dptl1minntinll Iph jill 011 tIll dtwlopllIlJIl of H HIli rOI1ll tlllbidity 111 hpl than I (olot rI
jJlIlpOP-ofallnlyi-I ( p(lllil1thb IIllijOI1ll turbidity or 1llt[lIinmiddotd d(ltl of jgtIp(ii(JlI l)~ lIltlkillU tIl plllltollllmiddottri( ntdillU al tandinu tiJlH~ (dlllilll wlli(h IhlllH(lill-- IP 1llutinmiddotly tnhll) t1ll1t an hlsl~1 oil the (oJlItlIlllItion of IIlhlHI Ill I(ill (lIPIipitat((L
TIll -I(p ill till jll()(Plhul HIP 1-- follOylt (1) 1l~UIIL uJ1lplls of thwl UJfJlllHl (II tliddl(l HUt dlipd 11Illtplial an lXIllltel with11 Ill of till nlnll ill t (oU tlllltIPlll[gtPImiddotatlup oil Iath at 11 Cbull fol 11 minutl I) iIP1lIin(middot(lohd til( (XUtllhllll Jltldl lip to It middotml ynlmlll til( (nlifild by (Illlifllgiuu HlId thlPl IlI nliql1ot of tIl (IalioPlllxUlltl nll Uillltlmiddotll(t to l-llll OIlIIlIllril fiuk- (1) For a trial Ilnditlg 0111 III tlll j liJmiddot~t IllHII IIjI to Ohlllll with lilt Pll shy(ilitnnl a 1(11 it 111 (Dod fill llli lIut ( ptotoJIIltlil IPtlllillg-- of pllllntnl or liuht tlUtllIlillal(I oil n (lpel OphotnJlllllI at rase hng-tlt (If 11 llJ Ill Ol It lollllil1lPtImiddott lloyidld with tIll P10]11 I 1110110shy
Ihlolllltt hmiddot Ii1llI Olllhi lIatioll for -1IpItillg UJlproXilll1l tply Wtl P ]Plwth )0 mp are HHlltk TIll Illldillg lliJtaillld fol tIlt 4-milutl tliall(~ll-
bull
bull
bull
RAPID PHOTO~IETRIC DETERIINATIOX OF R(BBER AXD RESINS 37
ing are referred to a table of equhmiddottllut~ previously p1(pa1elt1 on the
bull basis of 4-minute reac1inJ~ for tilE nmge of lot1telltlatiol1- of rubber or resins to bE elHOlll1t(led tmd gidn thtmiddot -tnnlillfr tillIP fill rUbbEt or resins aiter prE(ipitlltiol1 lwfolE photoIllNliI j(tltlill1 un IUade The r(middotnmining dllplllatt aliquot lll then HHllil up te ol1l1Jle and lpoundadillg ale marle ut the -tandillfr tiUlE iudklltll ill rhl tall1lmiddot for the final r(adillg~ -1) 111( milli1lnm or p(tCPlltllt- of lllhbpL (II 1(-in pr(s(nt are rpadholU a prlpan(l table of lquiltlput for tlll photoshymetric readings h1~l(l ill pnell e1-E on pxpPlilmlItal lhln 1111(1 u-ing as stimtlltlds pure luhbll in 1l1bbtl milllYb aIHI guaYllh ll-ill- lxIHlatt~ in resins detNIl1111lttion I
LlTERATlRE CLTED
(1) lUnSbull 1fl36 THE mURMIXTIOS IIF IOTA RE I III OOl THER llT~II
F1 bullrol IlY U(T1l0fll UfSlfi ~rrnrl r flm lt1 KEYS TI Bill Chern 114 44J-l59 illns
t1 ~ICPHHlObullbull T 1J3bull~ lUTHOO roa THE PtRInCAnu Or a(lIUl IRrIlHU It of TIn
PLRIHEU Htllllflt [ i Bill lallllall 111 Rmiddot 711middotj iIlus
I ) RHBERG P B Ul5 A METHIlO Or ~u(ronrll-nl Hi tIII rUIl[1 f71 ii illlI
bull 14 Hoss W flbull and HARDESTY J O
llH IR1ltDII Of HfITilIZfmiddotR DllIJS ltt 1 Yl fll Off gI bern JIIIlI i ~middotmiddotlf IIl
101 SPEltCE D nnd CuoWELr ~I L 1933 DETER~n-ATIOo OF RtBBER Ii nrllllpoundRBfR Iusr 1uI II1 amI
Em~ifl cttIliIa~~ r Ell i 71middot7i l11 (HI WALTER E D
1U44 ISO~nlS OF PRTlltSrr 1trHpoundV bull l UI n W lHHt (Tnmiddot 1ETS FROM GiYI l~iIl lItr Clttrn SII J UI titJ middotn9--C1 ilIu
17 J YOEbullbullr H lO~( roLORIlETRT 771 IPmiddot nl -W Yurk f H Plrwptric hmica
naly-II rimttry lUll XphHHlnmiddot~ y 1 1
11
HI) ~ fPHELolzTRf 57 111bull Lin xw Yk t H lt PhmeHt CblUlmiddot ila AnaiY~l~-(H lithrry and XIhmiddotILpfIY Y wirh enomiddot rrJlllrjr hy H KtlJnJU11 I
t~1I --- and ~ARVER L 1f41 nlua-w ~in L liLhr IS IP ll~ XIW Yrk
bull For-sale by th~ ~a~fr1nt~nf1ent Dt~c~~ogtnts-~ s t1i rArnn~ut Pn~~~ tJffieshy
Washington 5 D C bull Pl lU ~nts
bull
bull
bull
RAPID PHOTOMETHIC DElEruIINAlION OJ RUBBEH AND HESINS 35
IAIILE 8-luriation inclieute rubller (mallSM of [1wIIle tissue bll thc 1111O0Illclc metwII
Vnrlntlon~Ilbher I (rom mean
ierCtnl Percelll ~OU -22 ~ 25 +27 ~ 20 +18 ~UO -22---------1_______ 51110 0G6 bullbullbullbullbullbull _bullbull
10 ro ----=ii41075 -01 1000 +11 1010 +13
rlln HI itil 1l9~ 1_ ___ =-~~~
115511 ~ US -111 III II 1575 -13 115 b tiS -I a 111 h WlU +22IIM-(middot bull 11K -1Ja Illi c 1000 +03 1J5H1 W +l)7 ll1imiddot tl 1575 -13
Mcnn 15951 131
1102-11 21fJ() +21l102-h _ ~~)SO -17 1102-c bullbull 21CO +21n02middotd ~OIiO -26
2 r~plusmn Il~ 21151 261 I -~-------bull---__ _~~_~______l-___--_
1 lhe$ 1111($ I1n (or SlIlIIllltS Stpnnltplr PHrilClld IIrtlrdlng 10 1hr prollIlIlr( OIiIIiIl(o(I on Imgt$ 4 to IC ~tcond nUlI1 hlr r(J)[ltnts stl1ndnnl llrrot of tilt 1I1(1111
1_1l1~ n-J(lri(iot in relli(Upound rpoundsins (lllalIsfs of VIOJII( lixsue b1 the lhomillric lII(lloli
-- ---~--- - __-------- shybull I I I I Varlgttton
_________~___ ~~lu_n_Jl_Q_~~~_____ ______I__~_o~S_J frOID lDean
Percent Percentgt458-1 ~65 +41IWtl-li 130 -a2Hli8c aliO +26S41i8-d bull 130 -32
1(-011 34I10Olifgt __ bullbull __ ~--====
li-9~2n 881) -06 li-9~2-b Si5 o ~HH2middot(middot S i5 -6$-H2middotd 000 +1
8851 054
O i5 +6 9 i5 +6 950 -20 U75 +6
H-liG3o-n bull -1 n-li6~b bull __ _ -IH-IWH +4H-l61511 bull -1
1tmiddottlU
62~-lI __ 62~-b ij24-( bull OH-Ji
(-Ull
I rll(St oluls nre tor separately ~xlrflCled SllllllllCS IlctOrdlug lO procedure outllned ou pages 4 to 10 i Secoud number r~prtgeulS stulldMd error of lIe menn
36 TECHNICAL BULLETIN 920 t ~ DEPT OF A(]RICCLTCRE
ReUUER A~ALYSrS I~ CRCOE-RcuUER PROOCCTS
Sew rapid photometric m(lthod~fol the ddellllinttion of rubber and reii Hi ill uaYllp ti--ut htp lllell pIPHnl pd oil pag( ~l to In A brief H1111111tlY of It similar rnpid llHthod fm 1I1hb~rllnltlysis of u1lulcanizNl tlIldp lubbll pl(Hlmtlt whielt i~ bn-(tldo on the prill o
ciples dehtilcd tlllLe follows Duplltate nt-gm sllmph of the finely cliyiliNl IlInttlitiup wlirllll out [~ei-()l (all hl lIf((tinmiddotjv INd to lt1iyidl till alllpl) TIll kltolll-olubll portion of till )111(11( tlrc di-olved a- indh-Htpd fot thmiddot lllnkill~ of -tlllHlunlluhhll olutiou Oil Pt 1II hut tIl IUlIp Hn lIn l-fplImiddotd 10 lHI-ml rolllllltti( fln-k antil1ltld(lup to Olllll1l The bnlulUp or till JllO(ldllll i- thatutlilllll on paWs -1- 1 IHI Ii 111( 1(111 1- nIP IXPIP--pd nil til IHi or Iw oligiJla w(lullt of I Ill (I11l1p-I1l11Ilt1 1)(0(11(1
Hupitl PlllimiPJojgtiWllllllllh llIltllOd~ fOJ Ihl llPtlmiddotminntion of ImiddotUlJbll tlnd 1(-illo- ill -111111 Illllph of gutlYllll tiUl IIll dl-eli)ed 111() IlltlY d~o Ill nltlI1lld fOl III Iwl Illhlwl- and l~iJlmiddotb(lLiJlg plant TIllt l[Olllhup hns nlo b(l1l ntuptpl fot IIH lltlIll1illtltioll of lllhbpl ill 11lHhrublwl Pl(Jdlld~ HIIl 1111 hI ndaptld JoJ IIll ann lysis of ynt1J(gt( ic lllbbl[- The llllthmb HIP 1gtn(11 fill tIll fol1owill plimiph- III Grinding
tIll PIOPlly driPl t i~lIl 01 Ul tillg tIll pnHhHt to tll l((lllilllllh~lel of filWlH-- til plllllit qIHlIllilnth( lXIIHtioll 01 IIlbhlI 01 1(--IJl- () llsing oXWllutld olnuh (kttoJls IIt(talp and() fllltil for LIbbel and IH(ltIlIlyptIJllIllIoolYlnJld-o flJllh 101 niJlsl with t(lathelr high IlPililig points 111 to n C) l]olle or in mixt tIll thllt Pll mit tlll rnphllxututioll of luhll(l OJ [middot(ill ill ~() to (l mi1lutp It r(latiwly high 1lllIllllltlltP Ill to 1~11 ) l) lllllipitntillu till luhblI OL Imiddot(ill frolll aliquot () f till oltn ion I IlIlllI-i () f Hlltabhmiddot pl(~(i]litallt (willifhmiddotd lthmwl fOl IIlhlHI Hild llitlifild lllr fOJ JP-illl t~) IIlHkillphotollllliilPIIIIiIlof PlllPlltal of liht tLaIlS mittUl(P lIftlI IlIlbll (II Il in PIlipitalioll 11 II WI( Iplllh thnt (limiJlall till PIIOl dill 10 xtralllOlh (0101 (till dptl1minntinll Iph jill 011 tIll dtwlopllIlJIl of H HIli rOI1ll tlllbidity 111 hpl than I (olot rI
jJlIlpOP-ofallnlyi-I ( p(lllil1thb IIllijOI1ll turbidity or 1llt[lIinmiddotd d(ltl of jgtIp(ii(JlI l)~ lIltlkillU tIl plllltollllmiddottri( ntdillU al tandinu tiJlH~ (dlllilll wlli(h IhlllH(lill-- IP 1llutinmiddotly tnhll) t1ll1t an hlsl~1 oil the (oJlItlIlllItion of IIlhlHI Ill I(ill (lIPIipitat((L
TIll -I(p ill till jll()(Plhul HIP 1-- follOylt (1) 1l~UIIL uJ1lplls of thwl UJfJlllHl (II tliddl(l HUt dlipd 11Illtplial an lXIllltel with11 Ill of till nlnll ill t (oU tlllltIPlll[gtPImiddotatlup oil Iath at 11 Cbull fol 11 minutl I) iIP1lIin(middot(lohd til( (XUtllhllll Jltldl lip to It middotml ynlmlll til( (nlifild by (Illlifllgiuu HlId thlPl IlI nliql1ot of tIl (IalioPlllxUlltl nll Uillltlmiddotll(t to l-llll OIlIIlIllril fiuk- (1) For a trial Ilnditlg 0111 III tlll j liJmiddot~t IllHII IIjI to Ohlllll with lilt Pll shy(ilitnnl a 1(11 it 111 (Dod fill llli lIut ( ptotoJIIltlil IPtlllillg-- of pllllntnl or liuht tlUtllIlillal(I oil n (lpel OphotnJlllllI at rase hng-tlt (If 11 llJ Ill Ol It lollllil1lPtImiddott lloyidld with tIll P10]11 I 1110110shy
Ihlolllltt hmiddot Ii1llI Olllhi lIatioll for -1IpItillg UJlproXilll1l tply Wtl P ]Plwth )0 mp are HHlltk TIll Illldillg lliJtaillld fol tIlt 4-milutl tliall(~ll-
bull
bull
bull
RAPID PHOTO~IETRIC DETERIINATIOX OF R(BBER AXD RESINS 37
ing are referred to a table of equhmiddottllut~ previously p1(pa1elt1 on the
bull basis of 4-minute reac1inJ~ for tilE nmge of lot1telltlatiol1- of rubber or resins to bE elHOlll1t(led tmd gidn thtmiddot -tnnlillfr tillIP fill rUbbEt or resins aiter prE(ipitlltiol1 lwfolE photoIllNliI j(tltlill1 un IUade The r(middotnmining dllplllatt aliquot lll then HHllil up te ol1l1Jle and lpoundadillg ale marle ut the -tandillfr tiUlE iudklltll ill rhl tall1lmiddot for the final r(adillg~ -1) 111( milli1lnm or p(tCPlltllt- of lllhbpL (II 1(-in pr(s(nt are rpadholU a prlpan(l table of lquiltlput for tlll photoshymetric readings h1~l(l ill pnell e1-E on pxpPlilmlItal lhln 1111(1 u-ing as stimtlltlds pure luhbll in 1l1bbtl milllYb aIHI guaYllh ll-ill- lxIHlatt~ in resins detNIl1111lttion I
LlTERATlRE CLTED
(1) lUnSbull 1fl36 THE mURMIXTIOS IIF IOTA RE I III OOl THER llT~II
F1 bullrol IlY U(T1l0fll UfSlfi ~rrnrl r flm lt1 KEYS TI Bill Chern 114 44J-l59 illns
t1 ~ICPHHlObullbull T 1J3bull~ lUTHOO roa THE PtRInCAnu Or a(lIUl IRrIlHU It of TIn
PLRIHEU Htllllflt [ i Bill lallllall 111 Rmiddot 711middotj iIlus
I ) RHBERG P B Ul5 A METHIlO Or ~u(ronrll-nl Hi tIII rUIl[1 f71 ii illlI
bull 14 Hoss W flbull and HARDESTY J O
llH IR1ltDII Of HfITilIZfmiddotR DllIJS ltt 1 Yl fll Off gI bern JIIIlI i ~middotmiddotlf IIl
101 SPEltCE D nnd CuoWELr ~I L 1933 DETER~n-ATIOo OF RtBBER Ii nrllllpoundRBfR Iusr 1uI II1 amI
Em~ifl cttIliIa~~ r Ell i 71middot7i l11 (HI WALTER E D
1U44 ISO~nlS OF PRTlltSrr 1trHpoundV bull l UI n W lHHt (Tnmiddot 1ETS FROM GiYI l~iIl lItr Clttrn SII J UI titJ middotn9--C1 ilIu
17 J YOEbullbullr H lO~( roLORIlETRT 771 IPmiddot nl -W Yurk f H Plrwptric hmica
naly-II rimttry lUll XphHHlnmiddot~ y 1 1
11
HI) ~ fPHELolzTRf 57 111bull Lin xw Yk t H lt PhmeHt CblUlmiddot ila AnaiY~l~-(H lithrry and XIhmiddotILpfIY Y wirh enomiddot rrJlllrjr hy H KtlJnJU11 I
t~1I --- and ~ARVER L 1f41 nlua-w ~in L liLhr IS IP ll~ XIW Yrk
bull For-sale by th~ ~a~fr1nt~nf1ent Dt~c~~ogtnts-~ s t1i rArnn~ut Pn~~~ tJffieshy
Washington 5 D C bull Pl lU ~nts
36 TECHNICAL BULLETIN 920 t ~ DEPT OF A(]RICCLTCRE
ReUUER A~ALYSrS I~ CRCOE-RcuUER PROOCCTS
Sew rapid photometric m(lthod~fol the ddellllinttion of rubber and reii Hi ill uaYllp ti--ut htp lllell pIPHnl pd oil pag( ~l to In A brief H1111111tlY of It similar rnpid llHthod fm 1I1hb~rllnltlysis of u1lulcanizNl tlIldp lubbll pl(Hlmtlt whielt i~ bn-(tldo on the prill o
ciples dehtilcd tlllLe follows Duplltate nt-gm sllmph of the finely cliyiliNl IlInttlitiup wlirllll out [~ei-()l (all hl lIf((tinmiddotjv INd to lt1iyidl till alllpl) TIll kltolll-olubll portion of till )111(11( tlrc di-olved a- indh-Htpd fot thmiddot lllnkill~ of -tlllHlunlluhhll olutiou Oil Pt 1II hut tIl IUlIp Hn lIn l-fplImiddotd 10 lHI-ml rolllllltti( fln-k antil1ltld(lup to Olllll1l The bnlulUp or till JllO(ldllll i- thatutlilllll on paWs -1- 1 IHI Ii 111( 1(111 1- nIP IXPIP--pd nil til IHi or Iw oligiJla w(lullt of I Ill (I11l1p-I1l11Ilt1 1)(0(11(1
Hupitl PlllimiPJojgtiWllllllllh llIltllOd~ fOJ Ihl llPtlmiddotminntion of ImiddotUlJbll tlnd 1(-illo- ill -111111 Illllph of gutlYllll tiUl IIll dl-eli)ed 111() IlltlY d~o Ill nltlI1lld fOl III Iwl Illhlwl- and l~iJlmiddotb(lLiJlg plant TIllt l[Olllhup hns nlo b(l1l ntuptpl fot IIH lltlIll1illtltioll of lllhbpl ill 11lHhrublwl Pl(Jdlld~ HIIl 1111 hI ndaptld JoJ IIll ann lysis of ynt1J(gt( ic lllbbl[- The llllthmb HIP 1gtn(11 fill tIll fol1owill plimiph- III Grinding
tIll PIOPlly driPl t i~lIl 01 Ul tillg tIll pnHhHt to tll l((lllilllllh~lel of filWlH-- til plllllit qIHlIllilnth( lXIIHtioll 01 IIlbhlI 01 1(--IJl- () llsing oXWllutld olnuh (kttoJls IIt(talp and() fllltil for LIbbel and IH(ltIlIlyptIJllIllIoolYlnJld-o flJllh 101 niJlsl with t(lathelr high IlPililig points 111 to n C) l]olle or in mixt tIll thllt Pll mit tlll rnphllxututioll of luhll(l OJ [middot(ill ill ~() to (l mi1lutp It r(latiwly high 1lllIllllltlltP Ill to 1~11 ) l) lllllipitntillu till luhblI OL Imiddot(ill frolll aliquot () f till oltn ion I IlIlllI-i () f Hlltabhmiddot pl(~(i]litallt (willifhmiddotd lthmwl fOl IIlhlHI Hild llitlifild lllr fOJ JP-illl t~) IIlHkillphotollllliilPIIIIiIlof PlllPlltal of liht tLaIlS mittUl(P lIftlI IlIlbll (II Il in PIlipitalioll 11 II WI( Iplllh thnt (limiJlall till PIIOl dill 10 xtralllOlh (0101 (till dptl1minntinll Iph jill 011 tIll dtwlopllIlJIl of H HIli rOI1ll tlllbidity 111 hpl than I (olot rI
jJlIlpOP-ofallnlyi-I ( p(lllil1thb IIllijOI1ll turbidity or 1llt[lIinmiddotd d(ltl of jgtIp(ii(JlI l)~ lIltlkillU tIl plllltollllmiddottri( ntdillU al tandinu tiJlH~ (dlllilll wlli(h IhlllH(lill-- IP 1llutinmiddotly tnhll) t1ll1t an hlsl~1 oil the (oJlItlIlllItion of IIlhlHI Ill I(ill (lIPIipitat((L
TIll -I(p ill till jll()(Plhul HIP 1-- follOylt (1) 1l~UIIL uJ1lplls of thwl UJfJlllHl (II tliddl(l HUt dlipd 11Illtplial an lXIllltel with11 Ill of till nlnll ill t (oU tlllltIPlll[gtPImiddotatlup oil Iath at 11 Cbull fol 11 minutl I) iIP1lIin(middot(lohd til( (XUtllhllll Jltldl lip to It middotml ynlmlll til( (nlifild by (Illlifllgiuu HlId thlPl IlI nliql1ot of tIl (IalioPlllxUlltl nll Uillltlmiddotll(t to l-llll OIlIIlIllril fiuk- (1) For a trial Ilnditlg 0111 III tlll j liJmiddot~t IllHII IIjI to Ohlllll with lilt Pll shy(ilitnnl a 1(11 it 111 (Dod fill llli lIut ( ptotoJIIltlil IPtlllillg-- of pllllntnl or liuht tlUtllIlillal(I oil n (lpel OphotnJlllllI at rase hng-tlt (If 11 llJ Ill Ol It lollllil1lPtImiddott lloyidld with tIll P10]11 I 1110110shy
Ihlolllltt hmiddot Ii1llI Olllhi lIatioll for -1IpItillg UJlproXilll1l tply Wtl P ]Plwth )0 mp are HHlltk TIll Illldillg lliJtaillld fol tIlt 4-milutl tliall(~ll-
bull
bull
bull
RAPID PHOTO~IETRIC DETERIINATIOX OF R(BBER AXD RESINS 37
ing are referred to a table of equhmiddottllut~ previously p1(pa1elt1 on the
bull basis of 4-minute reac1inJ~ for tilE nmge of lot1telltlatiol1- of rubber or resins to bE elHOlll1t(led tmd gidn thtmiddot -tnnlillfr tillIP fill rUbbEt or resins aiter prE(ipitlltiol1 lwfolE photoIllNliI j(tltlill1 un IUade The r(middotnmining dllplllatt aliquot lll then HHllil up te ol1l1Jle and lpoundadillg ale marle ut the -tandillfr tiUlE iudklltll ill rhl tall1lmiddot for the final r(adillg~ -1) 111( milli1lnm or p(tCPlltllt- of lllhbpL (II 1(-in pr(s(nt are rpadholU a prlpan(l table of lquiltlput for tlll photoshymetric readings h1~l(l ill pnell e1-E on pxpPlilmlItal lhln 1111(1 u-ing as stimtlltlds pure luhbll in 1l1bbtl milllYb aIHI guaYllh ll-ill- lxIHlatt~ in resins detNIl1111lttion I
LlTERATlRE CLTED
(1) lUnSbull 1fl36 THE mURMIXTIOS IIF IOTA RE I III OOl THER llT~II
F1 bullrol IlY U(T1l0fll UfSlfi ~rrnrl r flm lt1 KEYS TI Bill Chern 114 44J-l59 illns
t1 ~ICPHHlObullbull T 1J3bull~ lUTHOO roa THE PtRInCAnu Or a(lIUl IRrIlHU It of TIn
PLRIHEU Htllllflt [ i Bill lallllall 111 Rmiddot 711middotj iIlus
I ) RHBERG P B Ul5 A METHIlO Or ~u(ronrll-nl Hi tIII rUIl[1 f71 ii illlI
bull 14 Hoss W flbull and HARDESTY J O
llH IR1ltDII Of HfITilIZfmiddotR DllIJS ltt 1 Yl fll Off gI bern JIIIlI i ~middotmiddotlf IIl
101 SPEltCE D nnd CuoWELr ~I L 1933 DETER~n-ATIOo OF RtBBER Ii nrllllpoundRBfR Iusr 1uI II1 amI
Em~ifl cttIliIa~~ r Ell i 71middot7i l11 (HI WALTER E D
1U44 ISO~nlS OF PRTlltSrr 1trHpoundV bull l UI n W lHHt (Tnmiddot 1ETS FROM GiYI l~iIl lItr Clttrn SII J UI titJ middotn9--C1 ilIu
17 J YOEbullbullr H lO~( roLORIlETRT 771 IPmiddot nl -W Yurk f H Plrwptric hmica
naly-II rimttry lUll XphHHlnmiddot~ y 1 1
11
HI) ~ fPHELolzTRf 57 111bull Lin xw Yk t H lt PhmeHt CblUlmiddot ila AnaiY~l~-(H lithrry and XIhmiddotILpfIY Y wirh enomiddot rrJlllrjr hy H KtlJnJU11 I
t~1I --- and ~ARVER L 1f41 nlua-w ~in L liLhr IS IP ll~ XIW Yrk
bull For-sale by th~ ~a~fr1nt~nf1ent Dt~c~~ogtnts-~ s t1i rArnn~ut Pn~~~ tJffieshy
Washington 5 D C bull Pl lU ~nts
RAPID PHOTO~IETRIC DETERIINATIOX OF R(BBER AXD RESINS 37
ing are referred to a table of equhmiddottllut~ previously p1(pa1elt1 on the
bull basis of 4-minute reac1inJ~ for tilE nmge of lot1telltlatiol1- of rubber or resins to bE elHOlll1t(led tmd gidn thtmiddot -tnnlillfr tillIP fill rUbbEt or resins aiter prE(ipitlltiol1 lwfolE photoIllNliI j(tltlill1 un IUade The r(middotnmining dllplllatt aliquot lll then HHllil up te ol1l1Jle and lpoundadillg ale marle ut the -tandillfr tiUlE iudklltll ill rhl tall1lmiddot for the final r(adillg~ -1) 111( milli1lnm or p(tCPlltllt- of lllhbpL (II 1(-in pr(s(nt are rpadholU a prlpan(l table of lquiltlput for tlll photoshymetric readings h1~l(l ill pnell e1-E on pxpPlilmlItal lhln 1111(1 u-ing as stimtlltlds pure luhbll in 1l1bbtl milllYb aIHI guaYllh ll-ill- lxIHlatt~ in resins detNIl1111lttion I
LlTERATlRE CLTED
(1) lUnSbull 1fl36 THE mURMIXTIOS IIF IOTA RE I III OOl THER llT~II
F1 bullrol IlY U(T1l0fll UfSlfi ~rrnrl r flm lt1 KEYS TI Bill Chern 114 44J-l59 illns
t1 ~ICPHHlObullbull T 1J3bull~ lUTHOO roa THE PtRInCAnu Or a(lIUl IRrIlHU It of TIn
PLRIHEU Htllllflt [ i Bill lallllall 111 Rmiddot 711middotj iIlus
I ) RHBERG P B Ul5 A METHIlO Or ~u(ronrll-nl Hi tIII rUIl[1 f71 ii illlI
bull 14 Hoss W flbull and HARDESTY J O
llH IR1ltDII Of HfITilIZfmiddotR DllIJS ltt 1 Yl fll Off gI bern JIIIlI i ~middotmiddotlf IIl
101 SPEltCE D nnd CuoWELr ~I L 1933 DETER~n-ATIOo OF RtBBER Ii nrllllpoundRBfR Iusr 1uI II1 amI
Em~ifl cttIliIa~~ r Ell i 71middot7i l11 (HI WALTER E D
1U44 ISO~nlS OF PRTlltSrr 1trHpoundV bull l UI n W lHHt (Tnmiddot 1ETS FROM GiYI l~iIl lItr Clttrn SII J UI titJ middotn9--C1 ilIu
17 J YOEbullbullr H lO~( roLORIlETRT 771 IPmiddot nl -W Yurk f H Plrwptric hmica
naly-II rimttry lUll XphHHlnmiddot~ y 1 1
11
HI) ~ fPHELolzTRf 57 111bull Lin xw Yk t H lt PhmeHt CblUlmiddot ila AnaiY~l~-(H lithrry and XIhmiddotILpfIY Y wirh enomiddot rrJlllrjr hy H KtlJnJU11 I
t~1I --- and ~ARVER L 1f41 nlua-w ~in L liLhr IS IP ll~ XIW Yrk
bull For-sale by th~ ~a~fr1nt~nf1ent Dt~c~~ogtnts-~ s t1i rArnn~ut Pn~~~ tJffieshy
Washington 5 D C bull Pl lU ~nts
