RENDICONTI Soc. Italiana d i Mlnerellagia li Pdrologia, 32 (2) 497-510 (19'/6)

L EONARDO L EONI · , MAURIZIO SAITIA ·

X-RA Y FLUORESCENCE ANALYSIS OF 29 TRACE ELEMENTS IN ROCK AND MINERAL STANDARDS

RIASSUNTO. - Recentemente FIlANZINI M. et AI. (1972 ) hanno proposto una metodologia in fluorescern:a a mggi·X per la determinazione degli elementi in tmcce nelle rocce e nei minerali. Questa metodologia prevede il calcolo della concentrazione di un elemento in tracce attraverso la relazione:

" c • I Lk C ( 1) i i i • • i ,j j

dove CI e I , sono rispenivamente le concentrazioni e l'intensità dell'elemento in tracce e k'.1

coefficienti sperimemali che tengono COnto degli effetti di matrice dovuti agli elementi maggiori H.o, Na.o, MgO, AI.o" SiO" K,O, Cao, TiO. e Fe.O.) essendo gli effetti interelementati degli elementi in tracce tmscurati. Attraverso la relazione (1) ed utiliuando per la misura delle intensità uno spettrometro automatico Philips PW1450 sono stati determinati Se, V, Cr, Co, Ni, ~~~~~~~~~_.~-~~ ~ ~~~~ Hf, Pb, Th e U in ci rca 35 standard internazionali di rocce e minerali. Per determinare i comenuti di V, Cr, Ni, Cu, Zn, Ga, Rh, Sr, Zr, Y, Nb, Ba, La, Ce e Pb sono stati Utili12ati coefficienti k,., già calcolati da FIlANZINI M. et Al. (1972 ), mentre per i rimanenti elementi viene fornita una nuova serie di coefficienti.

Sulla base dei risultati conseguiti vengono inoltre discusse le possibilità analitiche della fluorescenza a raggi-X per l'analisi degli elememi in tmccc nelle locce e nei minerali.

AasTIlACT. - Utilizing powdet pellers, thiny.five intetnational standards of rocks and minerals nave been analyzed for Se, V, Cr, Co, Ni, Cu, Zn, Ga, As, Rb, St , Y, ZI, Nb, Sn, es, Ba, La, Ce, Pr, Nd, Sm, Gd, Oy, Hf, Pb, Th and U. CoefIicients for matrix eflects correction are given for the analytical lines of Se, Co, As, Sn, Sb, es, Pr, Nd, Sm, Gd, Dy, Hf, Th and U being the coefficiems for tne characteristic lines of tne other elements given by the authors in ptevious works.

The collected data poim out that all the analyzed trace elements can be determined, by X.ray fluorescence tecniques, with a good accuracy, in a unge of concentration comptised between 1-5 p.p.m. and about 5000 p.p.m ..

Introduction

Utilizing powder pellets, as pointed out by F RANZINI M. et. Al (1972), accurate trace element analysis by X-ray fl uorescence can be achieved by a full matrix effect correction, provided that the major composition of the samples to be analyzed for trace elements is known.

" Istituto di Mineralogia e Petrografia dell'Università di Pisa.

498 L. LEON I, M. SAlITA

Following the analytical procedure outlined by the quoted authors we have determined the contents af Se, V, Cr, Co, Ni, Cu, Zn, Ca, As, Rb, Se, Zr, Y, Nh, So, Sb, es, Ba, La, Ce, Pr, Nd, Sm, Cd, .oy, Hf, Pb, T h and U 00 35 international standards af rocks and minerals.

Tbe ehaice of these elements is mainly dependent upon tbc limit af the X-ray Auorescence sensitivity. Practically, with the exclusion af some ligth elements as F, Sand CI, we have choosed ali the trace elements whose amount in a rock cao be greater than 1·2 p.p.m ..

To Dvercom e matrix effects the following rdatian (FRANZ INI M. et Al., 1972) was applied:

c, " • --0"'.-"-­

L k, ,c, j~ 1 ... , J

111

where, for a trace element i, li represents tbe intensity of the characteristic lioe, C the concentration and k',J the coefficients that take imo accou nt the influence of the major components of a rock (H20, Na20, MgO, AbÙ:l, 5i02, K20, CaO, Ti02, Fe20s).

KI.J are experimental coefficients and, as pointed out by FRANZINI M. et A I. (1972) do not correspond exactly with mass absorption coefficients; they depend on: a) ahsorption of both incident and emergem beami b) possible enhancement effects; c) instrumental conditiom.

Experimental

The characteristic line intensities were measured utilizing a Philips PW1450 automatic X-ray spectrorru:ter. The selected imtrumental conditions for the analyzed trace e1ements are given in tahle 1.

To determine the coments of V, Cr, Ni, Cu, Zn, Ga, Rh, Sr, Y, Zr, Nb, Ba, La, Ce, Pb we have utilized tbc k!.j coefficients previously determined by FRANZINI M. et AI. (1972) and LEONI L., $AITTA M. (1975).

5ince the kl,j coefllcients far the analyticallines of these dements were evaluated starting by intensities collected with a different equipment (Philips PW l540 manual X-ray spectrorneter) a preliminary calibration has becn neccssary. This calibration has been made comparing the inteosities measured with the two different X-ray spo:trometers; the following relatioo has been applied:

121

X-P'.r,y FLUOP.ESCENCE ANALYS IS OF 29 TJI;ACE ELEMENTS "'o. 499

TABLE 1

ln!trttmmtal condi/ionI

El .... ~t AndyUcal Une x- ray tulHo Cry lul Detec t or DlIcrie. CollU..to r

" .. Cr( t O 1tV,60 ..... 1 LIF(200) n"" .c. , .. Une

,. ~ Crl9(l KY,30"",1 LiF (220) Fl"".C. , .. fine ,. ~ . Cr(to KY,'O .... 1 Li' 12201 F!"".C. ~. ,,~

" '". Cr(40 !tV,VI .... I LLF IZ201 rl".,.C. ~. coane

V,Cr , Ni,Co .. • ISO KV,H ..... 1 Lit(220) fl"".C. , .. fino

" •• • (50 "-V,H !!lA) L1Y(1201 Scint . , .. Une

lIa , C@ CO. • 160 "-V,H ..... ) L1P 12201 r1".,.C. , .. ,,~

~ CO. • l'O KV, t 5 ..... 1 LiF(2201 '.C.+Se1nt. , .. fina

" CO . • l'O JeV, t 5 ..... 1 L1P(220J Scint. , .. ,,~

~ Lf, .. • (SO KV,45 .... ) LiPIHOJ Selnt. , .. ,,~

La,Pr ,Nd,

b ,~ ~ • (60KV ,t5 .... 1 LiP (220) n ..... c. ,.. Une

O. .. .0.9(60 JeV,20 .... 1 LiP (220) Sclnt. , .. cOln.

zn,Oa,lO>,Sr

V, Ir ,Nb .. A~ (60 KV,lO .... ) Li' (220) Scint. ,. . U n.

~ . , Co J.<j(SO 1tV,30 .... 1 LiF (2201 Scint. ,.. Une

were, for a trace element, (kl.J)1 are the values of the coe.fficients reported by FRANZINI -M. et Al. (1972) and by LEONI L., SA ITTA M. (1975), (kl.J)2 the coefficients utili:u:d for the analysis and H a constant computed according to the followi ng rdation:

" . (3)

where Il and h are rispectively the intensities (counts sec.) measured with the manual and the automatic X-ray spectrometers 2nd n the number of standards utilized for the standardization.

For tbe other e1ements (Se, Co, As, Sn, Sb, Pr, Nd. Sm, Gd, O y, Hf, Th and U) the kl.J coefficients were experimentally determined foUowing the same procedure as described by FRANZINI M. et Al. (1972).

The values of these coefficients are given in table 2. In table 3 are reponed the intensities of the analitycal lines, measured on some internationaI standards, of the elements for which the kl. J coefficients are given. These data are useful for other workers concerned with references standardization. Thus, to utilize the k l.J coefficients reported in table 2 it is necessary to compare the intensities (counts/sec.) collected Oll a different X-ray spectrometer with thase reported in table 3. A relation similar to that previously described can be used.

Ali the measured intcnsities have been corrected for thc background that was mcasured, generally, im mediately before and after the angular position of each

500

•• ,. .. .. .. " .. .. •• " " .. '" "

',' G.G001l

Q.OOGH

'1.00032

G . ODH)

Q.ooa . 0.00'1"

O.OOlU

'1.001'11

0.0026)

O.OOIU

'1.00114

'1.0'12"

" .000.'

'1.0'1011

0.00\91

O. !IOlle

0.00'1 14

O.DO.H

0.0'14)5

'1.001 "

O.OOIU

0.'10119

O.GGIH

0 . QOU9

O . OOJ H

0.G0 6 U

O . OOIU

0 . 002 0 4

'" '1.0021.

G.aDIH

0 . 00086

'1 . 001'1 •

'1 . 0'1161

'1.002'1'

O.GIOH

G.DO/H

Q.OOIGI

Q.DOH'

0.DOlI1

O.GGH'

0.0021.

0.00H6

L. LEON I , M. SA ITTA

TARLI 2

kiJ co~flicic nts

AI,O]

o . GOlll

O.OOhl

O. OOOH

O. QOH.

O. OOS.\

0.002))

0.0 114'1

o.oo'n O.ODIII

O.DOlI]

O.OOUI

Q.007n

'1.00221

O.OOH'

S'DI

0.0026'

0.001"

0.00 106

0.00191

0.00"4

0.00191

o.onu O.OIOU

0.009).

0.00611

0.00114

O.OOl6l

0 . 00ll 6

0.00260

TABLE 3

',' o.ooaa 0 . 006\]

0.00H3

0.01162

O.OIIU

o.oun o.onu O.Ollll

0.0290'

O.OUU

0.01614

O.OZZIS

o.oona 0.00101

'" 0.00111

0.00619

O. OOHI

0.01'"

0.01."

O.DI'n

o.ono' O.Oll"

O.OZlll

O.Olt"

0.011\7

0.01216

o.oo,a O.DIOH

TlO l

0.001l9

0.00649

O.OOlU

O.OIHO

O.Olto.

0.00163

0.01'17

0.OU70

O.OlOI6

o.Oltn

0.01112

O.DIllO

0 . 01016

0.011"

lnumitin (count/s) 01 lhe aflalyticallines 01 lhe elements lar which Ihe k'J coefficientI are given

.. ot LI.' o. n.l CI •.• CM LI. • ' M-C •• en·, Il.'1 'Col n.) n-, Il.' n-, IJ.' • e'-1 'l.I n ".i l .. -I ._.

."1 " .• OCR-I 101.1

.. n.' n ",., H-, "., .'"-1 n'.1 • '"-L •.• 'CC-\ n.t 'TI_) \1.1 • ' o-n l ... .'H_P III.' n-I Il.1 ., .... 01.1

"!c.H. I.' u 1.1

.. n.1 '0 . 1 Il.1 n.' u .• l' .S n.! .... ". ., .. /0.1 1O.! n'.l 110.0

no.' 11$.' 1l1.1 l1S.1

".1 HO.! U. I n' .l '01.' " .. " ., 101.<

19 .•

.. .. ,., .. H.'

lO •.• .. .. ,I.' ". ,,. ... n.l • •• ... .. ,

U.' Il . ,

IU . '

• 11 .,

" .' .. Il.'

•.• o ...... « ••

.. .. ., • .. . , .. ,

" ... .. , .. .. , ,. , ... , .. '.' . , , ..

o. o.

• o. H. .. ..

.. •• ... .. , .. L' o., ... ... • , ..

o.,

'.' ... .. ... • • ... ... ... o., .. ., .. .. " .. . ..

.. .. , l' . 1

• •• 10. 1 L, •••

4\ .1 IO .• li .• · .. ., .0 11.1 n., · .. · .. · .. .. · .. Il.' · .. · .. .. · .. H,'

IIt. , IU.' ...

" \l., .. .. .. " .0 <o., o. • . ..

H.' , .. ... n.' .. · .. • •• ., ., · .. 11.2

• .. .. .. ... 21.S . .. ,.

.. ".1 n.l Il . • ... , '0.0

lU •• lS.'

Il).' n.l ".! . .. U. lI.O n

" '''' " . 1 ,. , ., ..

.. l n.! . .. , ..

.. ,. , ,. ,

IO.' .. , Il " 19.2 ,. , 40 .• IL ., .. , ••

IO. ' o., .., •• L

• ... .. .,

.. · , .... ".2 ,., "., 11.! .. .. " . .. 11.1 .. ,. .. •

• .. . .. ... . .. · .. " .1 ..

. .

., .. .. , l. I .•

Il.' , ,., .. n., Il.' '. l ",I ...

1).0 lo Il.1 , l.' o •• t.. .,

10.0 L 1.1 ,., ... t. l •.•

'. l I.' '.1 •.• 1.1 • ... " ' l.' no , l.. 1.1 ..• I.' ••• l,O

..• I.' ... .. 11.1 1),1 .. , . I.' IO o

" .. " . .. , .

Ul . IU. Hl . ...

U ... 1011.

" . ... n " .. .. ". a.O

• "'.0

• . .

ilI.'

• ..

hlO)

0.00111

0 . 004H

0.D06H

O. OlIU

0.03$60

O.OOIH

O.OIIH

0.001"

0.01011

o.oun o.onu 0 . 02198

0 . 0 14 12

0 . 0 16 21

• . .

10 . 1 .. Il.' 40 .• · .. " .. " '0. o

• · , u.

• . .. " . •

• .. lU. I

characteristic line (a value corresponding to the average of the two background measurements was taken). Sometime, owing to partially interterences of the peaks, the backgrounds were measured away more than 2~3° from the angular position of

X-RAY FLUOR ESCENCE ANALYSIS OF 29 TRACE ELD1ENTS ECC. 501

the peak; in these cases the background curvature was taken into account. For a restricted range of 2 e (about 7-8°) we have fou nd experimentally 'that the background curvature is exprimible by an exponential function of the type:

18 - e -aH b ( 4)

where 18 is the background intensity, >.. tne wavelength, a and h two constant tbat depend on the instrumental conditions and on matrix composition. Table 4 a reports

TABLI!. 4

lnu"I"~nu h~twun lh~ characU,ùlic linu 01 th~ analy%~d el~mt$ and valuu 01 lhe conitanU K

""a lytlcal In t err.rlnv ChaucurloUc Une utill • • d lIn. Hn. fo. correcdon and ... .tu,," o! k

UM • Se k. Ca ~" Ca l'I O.QtlO

" •• TI l' ,,~ O.Os:lO

,. ~ " ", " .. 0 .04'10

Co h Fa 1<1, r. l'I O.OUO

.... l. Pb L • Pb L'U 0.S1S1

B. LJ Co w C. U, 0 .5200

~ w C. "'" C. L' I O. I'SO

~w C. L' I C. !.l, 0.04 SO

.. w 1.& L'I ~ w 0.'160

" •• Rb "', ~ .. 0.2 n o

Zr la Sr IJ, Sr k. 0 .1100

tbe background values for diffe-rent matrix Ifl the region of continous spo:trum comprised between >.. = 0.944 A and >.. = 0.732 A. Tbe lin~r extrapolation has been made against the 2 e value5; the exponential extrapolation against tbe wave­length values.

Tne comparison between tbe observed ~ckground measurements and those evaluated by the two different . extrapolations shows that tbe exponential one is more dose to the observed background values.

In the intensities measuremenu of some characteristic lines it nas been necessary to make corrections for line overlaps. Relations similar to those utilized by FAAN­ZINI M. et Al. (1972) and by LWNI L., SAnTA M. (1975) nave been applied to overcome these interferences, that 15:

502 L. LEONI , M. SMTTA

where l'A aod l''A are resptttiveJy the corrected intensity and the measured intensity (corrected for background) of the analyzed e1ement (A), la the intensity of a characteristic line (free by interferences) of me interfering element (B) aod K a constant computed according to the following ratia:

, . , • --'- (6)

" where l' B is the intensity of the interfering li ne of the e1ement B measured al the 2 a value of the characteristic line of the analyu:d eJement (A). l'n aod lo are intensities referred lO characteristic lines bdonging to the same spcclral .serie and measured on samples absolutely free of the e1ement A. In some cases, where the peak of the analyzed trace e1ement is afFected by the presence of the tail

TABLE 4 a

Background interpo/ation in th~ ugion of th~ continuo! !p~cJrum ranging trom À. = 0.944 to À. = 0.732 A (X-ray Jub~: Ag operating at 60 KV and 20 mA; crystall

LiF (220); d~Uctor: Scintillator tvùh discriminator; fin~ col/ima/or)

"'d9r"",nd valu .. ko .. " .. , •. '

" , _ •• v.<! U..-n btrap. hpoft.Pxtrap. ... l' .'" 0.1H 2111.0 2' U.0 21 ... 0

31.00 O.H ' 2.41.4 12~.1 1101.0

ll .oo 0.10' "H.' ' 182.0 lU2.0

35.00 0.151 1)01.' l !<ll . I 12tl.0

11.10 O. , .. &02 •• 102 • • &02. '

S102 lllO.' lno.' l nO .'

lHO.' un.l 'U2.1

1111.1 126' . , l U'.1

':10 .2 101i.5 'U .• " ' .0 '14.0 61' .0

hlO) H2.1 112.1 141.1

lOt.0 116.0 »1.'

251. 1 271.' ln.5

120 •• 228.7 211 . 5

"1.0 141 . 0 l n.O

of a peak of a major dement (sec: for example Co Kez: by Fe Kez: or Se Kez: by Ca Kf3~) the intensities ID and l'D of rdation (6) are referred respectiveJy to the maximum of the interfering peak and to the angular position (2 a) of the peak of the analyzed element.

x-Jt,W fLUORESCENCE ANALYSIS Of 29 TJtACE ELEMEI'ITS ECC. 503

In table 4 are reported ali the interferences encountered in the intensities measurements and the values of the K constants.

In the analyses of Cu, Cr and Ni it was necessary to take into account me presence of these elements either as trace in the target of me X-ray tube or in me material of the X-ray spectrometr cabinet. The amount of Cu, Cr and Ni due to these sources was evaluated on samples of pure AbOs, Si02 (quartz) and CaC03 absolutely free of these elements. The following values (p.p.m.) were obtained:

" "' Co

A12

03 " 7.' "

5102

3l 6. , 'p

C,OlC03

30 6 . 6 " M 30 7.0 so

Table 5 repons tbe concentration of the trace element (p.p.m.) obtained on the anaJyzed international standards (US.GS. standards: G2, GSP.l, AGV-l, BeR-l, PCC-I and DTS-I; C.R.P.G. and A.N,R.T. standards : GA, GH, BR, Mica-Fe, Mica Mg, VB-N, DR-N, BX-N and DT-N; G.S.J. standards: JG-I and JB-I; N.l.M. standards : N IM-D, NIM-G, NIM-L, NIM-N and N IM-P; C.S.R.M. standards: SY-I and SY-2; N.B.W. standards: 69a, 88a and Ib; Ingamels and Suhr carbonate sta ndards: 401, 402 and 403; un-X standard: Len-NS-I; Z.G.1. standards: BM, TB, G-M and KH).

Table 6 reports far each analyzed trace elemem me detection limit and the precision at a level of concemration of IO p.p.m.; both these parameters are referred to a matrix of pure Si02 and have bttn evaluated far a couming time of 200 5eC ..

Data listed in table 6 are indicative and depend, the detection limit in particular, on the matrix composition.

With the exception of the elements that have been analyzed with the Ag X-ray tube (we have utilized an Ag X-ray tube of 1600 W of p:>wer) far the other elements th~ values relative to the dettttion limits given in table 6 represent, at present, substantially a limit far X-ray Auorescence ana1ysis of the trace e1ements in a rock.

Conclueiom

On the basis of the results rep:>rted in table 5 we can conclude that the method prop:>sed by the authors is sufficient1y accurate for petrographical and geochemical researches. With some exceptions generally thc agreemcnt between our data and literature ones is good.

The prccision of thc method depends substantial1y on the standard counting error, Accuracy depend on the h , values.

504

-• -~

~ ~

.;; • {l • ~

11 • ·2 ~ • ~ ~

·5 -~ ~ • o ~

{-• • ~ • -~ i -~ ~ ~

.il • ~ '"

, o

"

, • -O

" , • -•

• O

< O

• O

L. LEON I , M . SA In'A

""_.-.- .-_ ... ~.- _-4 ... .. ... "'.- ...

'40_0 .... 0 "' .. ... . .- ....... . ...... "'-0_ ........... _ _ ............. -... ~~~~~~-- --------...... ..,- ......... ...... ~ ......... OO ..... C ..... N ........ ~ ...................... CC ..... ... ...... __ ... _ ........ _ _ ... _... N_

•

_ ... ... _...... .-_.- .. .-.- 0__ __ .-.......... ___ ..... '0_'" 0_"_" ._ .. __ ... NN . ........... '''''''00''' __ ......... 0 ........ • ... _0

~~~~=~e~e~::~~~~===:~=~=~=~= O'" N'" ........ ... ...

- --.- ____ "_00_ ...... _0

~~;~~~~ ~:~~~ O~:~~ --------000 ..............

------- ----- ----- ...... ---"''''­--------.. O ..... ... ...... c C "' ....... O ... O ..... ........ _ ... _ .. c ... _ ................... "' ......... "' ... ......... ... .. ---- ... "'-• -.

-- .- --_.-___ "'''' ___ 0"'_"'_"''''''''' __ '- __ --O, ... 0 ... _ ............... ·· • ...... 0_ ... ____ 0 ... _

... __ ...... _ ... _ ..... _ ... __ .... 0 ..................... "'''' ......... ... -----------------------------...... ...... "'-'" ... -. ..... :::~: • ............. -O O ... "" .......... • , ---... . -• • • • • -

O - -O

0 __ 0 __ --. _. O . • O O . -O .-_. ... o. • · • -. - · • ------- ------• • . . , · , • • · • , , • .. O •• , • O • -- • , -• ::!:~::: e o , O · • •• o · -o · . - • • •

-o -- -o . ~ _ ...... ..... ...... _0..... o ..... . ... o __ ..... ... ... 0., .................... .. ... ,.,-.., ... _ .... - -... --- ......... ... ~~~~ ............. _ ..... _---"' 00"'0'" ... ~ ... -..... ., ..

• O~ ... _ ............... N~ ... ~O ............ O.C4 .... N",_ ONon_ ...... N ... _

• •

........ _ __ ... ~ ____ ~ ___ o"'" .-... · 0 .... _ ..... • ... «>~_o · ... _ . ........ 0 __ ...... __

... .. ·_ "'N · ...... NO ... •· · ~ ...... ~o . .-' ... ..... ~~~~~~~~e~~~~~~e~~e==~~~~~~~~ ...... ONO~O ... ~ ~ "'~ ~ N ~ ..... v ~

• -o -• 00' o • o. •• , .. -• - O. • • • .0 • , • o. o -. • • -- -. • • •

o o ._ , • • ~ o o 0 0 • o • • • • o • • • .. o • • > 00' o NO • • • .. • • o • " O • • • O o • • " o

" -• , • • • , · • " • • · • • • o >

• o • • • • • • , o •• o " • • o · , • • • • " • " • o <

" • o o • o o • o •

o !

~ e ~

" ;i

~

x-uv F LUOR ESCEN CE ANAl.YSIS OF 29 T RACE E.LEMENTS ECC.

-o~~ •• ~ ~~~ ~~~~~~ ~~~~ ~ .~ .~ . ·o_~ ·o~o .~~~ ~~~ -~~~~~ ~ , ~ ~~~.~.~o .~~~~~ ... ~~~_~ .... ~~ .

~ ~~_~ ___ ~O~~~ __ ~OO~~~~N~~~~_~_ U _~~ __ ~_~~ __ ~ _____ ~ ____ ~ _____ _

~ ~ ~ ~~~ ~ ~ ~

• , • o

• , • • "

" ~

, > o <

N , • •

, • •

~~~~::~~~~~~~~Ncc~~~c~~~~c2~c • o

N _ _

~ __ ~~o~ _N ... ..,~N~~ ::!z:!::::!:!:::. o • "'_N.O~ .. .......... -~ ..... • NO

~;~ ... ~ c c"'::::~"'..,"''''''' c~'" c o

4_ _ __ _

.~~------."'-"'- .... .., ...... -~ .... -... OO ... OO ... .., _~ ..,~~N_· ... ~O"'O ___ ·~~ ... _ _ ._""''''N ___ ''' __ ''''''~~''' __ ''''''_'''''' ~_'''

------~~----- - -~------------~ ... ... N'" ~

m O"' ...... ~_OO ...... ..,O_..,N ........ ~ ... o .... ~'" ... _ NO_ ...... "'N_.~ ... ~N _~..,~_~_

- -- ... "''''N_..,~ "'''' ~ ... _ ,..~_. ...~ __ ~~

• .., •••• ._. •• _~ • ... _ .. "' ... 0 __ ... ~..,,,, ... _ ... ,,, ...... N ... ~~.O ·~"'_N"'·· .......... _ .......... . - _ ___ ....... 0~~ ... N_44 __ ... ~~ ...... "' ... .., ... ~_ -----------------------------.'" ~ ...... ... .... ~ ... ~ ~

NN ... ~ ............. ~_. 4 ..,4 ... C"' ... _~ .... ~~C~.C ___ ...... ~~_N ~ ... ...

_0000 .... ~--­----­• "o N

• N

o

.0 "''''~ .......... ''' ... _ ... ~ ... ~ ... C..,_ ...................... __ ''' _ _ ... _ N ~ N~ " ... ~~N. ____ ~~~

... ... ... N

.__._.~ __ O_

4 "''''''''''''''_0 .o"' ............... ... --------.0"'_ ......... '" 00"' ...... _ .. ...

N

•

___ 0_ .­

"'~_"'O_N ~OO""O"'_ . .::.:!.:::z

... "'NN_ .... ~ ~"'O ... --.",-

o

----- ..... .­...... NO .. "'_'" ..... -... - .... -"'N"'_"'N~_ --------

---NO o o N <ON

:!:: <o .<

N

"'N_~~ ... ......... •

NO '0 N N

505

506

, o

" •

, O O

•

" , • •

Z , • Z

, • N

L. LEONI , M. SAITTA

~~ ~ _~o_~ _____ .... _~ ____ __ .... --~ .o~~ _~ __ ._ ~ ~ '.N_NNN~~ ~ _NN

00" ....... "'· .... _0_ . ... ~_._N~.O 000" -o ... o ~~~~~~~-~~~~~~-------------­~~~~~~~~~~ ~~~~~~~~ ~~

~::::::::~ · . • N

.... 0_"'''' _____ .... ,... "' .... "' ... '" ' ..... __ ... '" N ... ·0"_ ... _ ... · :-~.:!!.:::.~:::.:e_ee_::._.:::..:: ... .., ................ "' ...... .............. .... ... .,G"cc .... c_ ...

...... 0 .. _ ... NN'

~. ~

~~ ~N. N • .~ • • ;"::~:;:: • N • • • • O O -· . -• • •

~~~

NN_ -• • • • • O. O O

O • • ~ . .. • · _ N

------- -----• N N

O .0 O< N • • N ••• N N

• N • • -. • • - • • • •

~. ------ • O N ••• ••• ..... .n .... ", ....

"" • .. --- • N

_ N N

-------- -----· • ON. NN • ............ .. O N -.. -N N ............ • - • N

_0""""' ___ ...... "'0-"' .............. _ .... ................. "' ..... .. •

.. • O • NO. .. •

• N N

• O • ~. • • -

N • • - O 0_ • • e

"" . -O'" ... ::!e.:::.~:~

""!~

, O

•

• O

~ O ~N N

• , , .. - • • O O O 00 • O O

0 ___

• • ••• N N • · -• , • • O O O · • NN

• • · .-

.. ~ ~

• • ee • • • ..

• O • O • • O O

_0-00"''''_'''''' · . ................ "' .. --------~--~ ...

...... .,"' ... "' .. 0 ... "' ......... "'''' NN ............................ .., N' •

c"::: ... ::: .......... " .. 2 c •

--- ..... __ "' ___ 0""''''''''''' ................. _ __ ...... 0 ............ "'00·,... ......... "' ___ 'H __ ...... .. ___ NN ___ ..... N"' .......... "' ....... "' .... --- -------------------------~ ... ......... ... ... "' ... ."." • N N • -- •• • N' • • N · O O O. • • • O • O • O O .. • N, "" N N N • • N N

N N

~~ 8 ~ • •• -0_0_ ~ . •• • N .N • • • • · N • • • N • • N N N N • N N N • N • -------• • • • • • • • • • " · · • N N • N •• • O. • O O. • •• N • -• • N • O -. N

• N. • N • • N • • • • • • • N N

• · ,N • • • • o • • o O o • • • • · • •• .- o • O • O O • o NO o • --" Z --o • " O • • -O • • • " Q

X-RAY FLUOI\ESCENCE ANA.LYS IS OF 29 TRACE ELf..M.ENTS ECC.

•

" •

• , " o

• E , • " i

• • , • " . -E

• , • O

• , E

" •

o , E

" •

• • , • • • "'''''''' ''' ''''''''''''''~O

..o", o ..,"'''' • _ ............ "' .... O .... _N.., ... .... .., "'"'" ",..o",,,, ... .... ••

• •

•• '" "' ... ".., ... • • •

• "" . O • •

•

· g , •

• • •• o •

•

• .. , o. •

...... ... ........................ ...

"''''''''''''O''''''''''''''''''''''~

o "'~~ ~ .... .... ... 00 ............ .... ...... N ....... _'" '-' '-' ..... '-' '-' '-' '-'

" g .. • •

•

... '" ....

o ,

•

00 O' . .

• ............... 0 ....

.... NN ......... " . "' .. "' ............... _0 .. ... ... '" '" "'''' .... • ••

~O~~ ..... ~~:;::il

.... 0 .... 0 000 0 .... ON "' OO ..... ... ....... '-' '-' '-' '-' '-'

· . ::;::~:eN~ • • •

............ 0 .... 0 ....

•

o

... .... -'"

"'''' 0 ...... 0.., .... 0 ........... ... ... _ ...... .. '-''-' .............................. .....

• •• 0_' • • •

· . •

o • . _. • • O . _.

... ~ ,,"' ...

•

...... ... ...... ", ... ., . ". . .. ............ '" e:::~~~

" c c c

... ............... ...

O

• ......... ." .........

••

· • .. "O ...

O

507

508

" c •

c •

•

• • •

• • •

• •

• c

• •

• •

• "

•

•

•

• "

· • • •

L. LEON I, M. SAITTA

" • " ....... '" ...

-c

.,. ......................... •• ••

• •• ......... ..,,, .... ......................... •• '" o ~ .. .., o •

................. · N -=

~.... .... O 0 .......... 0 .... -- ........ ... ~~~~~~

N N

•

• •

"" ........ e ......... """"" c •

••• ••• •• ccco",oc",.,..,cc",cc

• ~

0"""''''''':<'' <:''

.- . ... ... "' ................ . ~:.=8=!!!!=e ...........

-. • • "' ... c:~:;:~.., .... c ... ;::: ... ... .., ...... •

............ "" . N

X-~Y FLUORESCENCE ANALYS IS 01' 29 TRACE ELEMENTS Ect::. 509

TAflLE 6 •

Detection [imits and precision at a concentration leve! of about lO p.p.m .. Theu parameurs have bun ellalualed on a matrix of pure SiO. (quartz) far a counting

lime of 200 s.

Il .... d •• Ihh '«<i.!o. D ... «lu \I . h ,. .. I.!.o

(p" , •• ) (,.p ••• ) (p., .•• ) (p.p . •• ) .. o., " , o., o. .. o o . , • , .0 o . • .. ,., ••• " '.0 o . • " .. o o.,

" o., o.' .. '.0 , .. h o., 0 . 0 " '.0 o.,

" .. o 0 . 0 " "O ... . , , .. o .• " .. o .. o

" ... o. , .. LO .. o .. .. o o .• •• LO ... .. o .• 0.0 .. '.0 , .. " o .• 0.0 " •• 0 '.0 o o .• 0.0 .. "O '.0

" o .• 0 . 0 .. .. o o .• .. o., o .• .. .. o o .• o ..o o .•

The method is applicable to rocks of widely dilferent composluon and in a great range of concentrations of the traee elements (from 1-2 to about 5000 p.p.m.). provided that the eoneentration of the major eomponents is known. At present, this is not a serious limitation; in faet regression method, based on a full matrix eorrection allows to earry aut analysis of rocks far major eomponents by X-ray Auorescenee, in a very short time (about 15 minuta far a rock).

Even operating with instrumental eonditians different from thase usecl in this work, the ki. l eoefllcients far the eharaeteristic lines af Se, Co, As, Sn, Sb, Cs, Pr, Nd, Sm, Gel, Dy, Hf, Th and U can be used, with a preliminary calibration, by ather authars.

We abserve in fan that the use af the kt.l eoefllcients obtained by F~NZINI M. et Al. (1972) and LEON I L., SAITIA M. (1975) with a dilferent X-ray spectrometer (k l •J eoeflleients far the eharaeteristie lines af Cr, Ni, Cu, Zn, Ga, Rb, Sr, Y, Zr, Nb, Ba, La, Ce and Pb) have given good results.

REFERENCES

MDO ATSUHI, KUJ.ASOWA HA] IME, ORMORI rnNO md TAKEDA Etu (1971) • 1971 compilatio" 01 data on rocks standuds Gl-l and 18-1 iusud Irom tbe Grological Sur~ 01 lapan. Gcoch. ] . Uapan), " lRI64.

Catalog 01 Sta"dard Rtft rtnu Mattrials, l b and 88a carbonatt rocks,. 69a bauxitt. National

Bureau of standard, Special Publicalion, 260, 1970. FLANAGAN F. ] . (1973) • 1972 valUtS /or i"ttrnational (tocbemical rtltrtnct samplts (U.S.G.S.

standards: G2, GSP·l , AGV-l , BCR-l , PCC-l IUId Drs.!). Geoc:him. et C'.osmochim. Aeta, 37, 1189·1200.

510 L. LEONI, M. SAETTA

FRANZINI M., LroNt L., SAITTA M. (1972) • A simpl~ method lO tllllluaU the ma/,ix tffleU in X-rS)' fluoresunu anolys;s. X.Rty Spectrometry, I , 1.:5I-U4.

INGAMELS C.Q., SUHA. N.H. (1967) - Chtmical and spectrochtmical arta/y!i! 01 standltl'd carbonllte rocks (400, 401, 402, 403 ). Geochim. et Cosmochim. Acta, .H, 1374·13'0.

KUKHJ.ENKO A. A., IUNsKI] G. A., IVANOV'" T. N., GAUCHOV A. V ., KOZII!.IEYA L. V., GEL­MAN E. M., BolNEMAN-$TUYNKEVICH I. D., STOLYAROVA I. N., SKI.1 SKlNSKAYA V. I., RI­SHOVA R. I. .nd METP.NTYEV B. N. (968) - Clarlu valut I 01 tht Khibiny IlJJt.tlfine massil (StandarJ Lefl'X), Vscs. MineraI. Obshchest Zap., 97, n}·H9.

GROSSMAN H. ( 1972) - Dit standardgesteinsproben dtr Z.C.! ., 6 Mittri/ung: Neue Auswertung du AnaJyun IIU/ Hauptkcomponenun der Proben G,anite GM, Basalt BM, Tonshieler TB, Kolkstd n KH and "SU AllsUJnlllng d~r p'ob~n Anhydrit AN und SchwtJwchi~/~ TS. Z. Angew. Geol., 18, 278-284.

LEONI L. , SAITTA M. (19n) - D~t~rminaljon 01 Ytt,ium and Niobium on standard silicat~ rocles by X.,ay fluouscence analrus. X.Ray specnometry, 5, 29·30

ROUBlr.ULT M. DE LA ROCHE H. and GoVINDARA]U K. (1970) . c.R.P.G. standards (GA, GH, BR, Mica.F~, Mica.Mg) and A.N.R.T. standa,ds (U~N, DR.N, DT·N and BX.N). Sci. de b. Terre, l', 3'1·393.

RussEL B.j., GoNDVIS R.G., DoMEL G. and UVIN j. (1972) - Prdiminary repo,t on IIn analysis 01 si" N/M·roc g~ochemical standt1fd sampl~s: NIM.N, NIM·L, NIM·D, N/M-P and NIM-G. National Inslitute (Johannesburg) for Me!JUurgy Res. Rep. No. lU.

SlNE N.M., TAYLOI W.Q., WI!.BBEN G.R. and LEwls C.L. (1%9) C.S.R.M. standards: SY-l, SY-2 and SY-J. Third reporl of analytica1 data for CAAS sulfide and Syenite rock .tandards.