agilent gc-maintenance
TRANSCRIPT
Maintaining Your Agilent GC SystemMaximize your efficiency. Minimize your downtime.
Operate your lab at peak performance
Troubleshoot difficult problems
Select the right PerfectFit supplies
Plan preventive maintenance
Introduction
With many labs today finding themselveswith reduced staff, our GC MaintenanceGuide was designed to put 35 years ofAgilent’s GC knowledge right in your lab.We share everything from essentialmaintenance schedules to keep you up and running, to invaluable troubleshootingtips and problem solving methods. We’veeven included an easy guide to help youorder the right Agilent PerfectFit parts and supplies to keep your downtime to a minimum.
At Agilent Technologies, we give you morethan the world’s best GC system. We giveyou knowledge!
2 www.agilent.com/chem
Maintaining Your Agilent GC SystemMaximize your efficiency. Minimize your downtime.
3 Gas Management4 Gas Types
5 Purities
5 Purifiers
13 Regulators
14 Tubing
15 Leak Detection
16 Flow Rates
19 SampleIntroduction & InletsSample Introduction
20 Vials & Syringes
Inlet Types
26 Packed Column
28 Split/Splitless
31 Cool on-Column
34 PTV
Inlet Accessories
36 Septa, Liners,Ferrules
37 Columns38 Column Maintenance
38 Column Selection
38 Installation/Setup
39 ColumnPerformance
43 Detectors44 Thermal
ConductivityDetector (TCD)
45 Nitrogen-PhosphorousDetector (NPD)
48 Electron-CaptureDetector (ECD)
50 Flame PhotometricDetector (FPD)
52 Flame IonizationDetector (FID)
55 Service & Support56 Expert Training,
Service & Support
PULLL
-OUT POSTER ENCLOSSEED
Troubleshoot
Troubleshooting
GuideTroublesho
GuideGCouGC
Don’t Miss…GC Troubleshooting Guide (pullout poster)
GC Maintenance Schedule (inside back cover)
This icon denotes a video that is available to view on ourweb site. Just visit www.agilent.com/chem/supplies to
view videos and obtain more information.
GAS MANAGEMENT
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Gas Management
The use of quality carrier gases is essentialfor consistent and accurate GC analyses.Proper gas management is key to achievingthis goal. Agilent provides a diverse line ofhigh quality gas management products —gas purifiers, regulators, leak detectors andflowmeters — all designed to preventcolumn damage and improve the qualityand consistency of your GC separations.This section explains how commoncontaminants like oxygen, moisture andhydrocarbons can damage your GC column,and helps you understand how to preventit. Also, look for practical information about regulators, the importance of cleanGC-tubing, and minimizing the likelihood of GC system contamination.
“Gas management is more than justselecting the highest quality carrier gasavailable. It’s about selecting theappropriate carrier gas for your needs,and taking steps to prevent systemcontamination. Agilent understandsthis and provides products that makegas management easy to implement inyour lab.”
Kenji YamaguchiApplications Support Manager
Gas Types
Carrier Gases
The most frequently used carrier gases arehelium and hydrogen, although nitrogenand argon can be used. Purity is essentialfor these gases since they sweep thesample through the column where it isseparated into its component parts andthen through the detector for componentquantification. Carrier gas purity is alsocritical to prevent degradation ofchromatographic hardware.
Contaminants in carrier gases can have a significant effect on column life andsubsequent analyte detection. Harmfuleffects include contaminant peaks
and elevated column bleed, along withcolumn and/or detector damage. Thefollowing sections describe the gases and purities that are necessary for gaschromatography carrier gases, as well as other support gases.
Support Gases
Support gases may be specific for detectorsor for applications. These gases includefuels, oxidants, coolants, detector gases,and pneumatic gases. The degree of purityrequired for support gases is dependent onhow that gas is being used, and whether or
not it will make contact with the sample.Coolant gases (carbon dioxide) andpneumatic gases (air or nitrogen) generallydo not come in contact with the sample ordetector. Therefore, these non-contactgases do not have to be the highest purityavailable.
For most applications, gases which are lowin oils and particulates are desirable; thus,low-purity “specialty gas” grade productscan be used. Fuels, oxidants and detectorgases, in most cases, do come in contactwith the sample and detector, and requirehigher purity gases.
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GAS MANAGEMENT
Sample Gas Type Function Contact Purity Required*
Air Pneumatics No Low Grade
Nitrogen Pneumatics No Low Grade
Limit of Detection required:
Trace (0-1 ppm) 1-1000 ppm 1000 ppm-1% 1%-100%
Hydrogen Carrier or fuel gas for detector Yes Research Ultra-Pure Ultra-Pure UHP/Zero
Hydrogen/Helium Mix Fuel gas for detector Yes Research Ultra-Pure Ultra-Pure UHP/Zero
Methane/Argon Carrier or make-up or Nitrogen for ECD Yes Research Research Research N/A
Air Oxidant for detector No Ultra-Pure Ultra-Pure UHP/Zero UHP/Zero
Nitrogen, Helium, Carrier or or Argon make-up gas Yes Research Ultra-Pure Ultra-Pure UHP/Zero
*Purities of gases depends upon the type of detector that is used. Use this table as a general guide only and refer to your detector manual forspecific gas purities that are needed.Low Grade = Specialty or industrial gases (≤99.998%)UHP/Zero Grade (99.999%)Ultra-Pure Grade (99.9995%)Research Grade (99.9999%)
Carrier and Support Gases
Contaminants in gases are majorcontributors to capillary columndegradation and detector noise, and can interfere with chromatographic results. Concentration of thesecontaminants vary by the grade of gas.
Analytical gases are available in manygrades of quality, from high purity(99.995%) to chromatography grade purity(99.9995+%). The higher the purity, thehigher the cost.
Identifying Contaminants
To make a proper purity choice it is helpful to understand the contaminantsmost common in GC gases and how they can affect your analysis. Commoncontaminants are:
Hydrocarbons and Halocarbons � decrease detector sensitivity by
increasing detector background noise
� can also cause baseline drift or wander,contaminant peaks, and noisy or highoffsets of baselines
Moisture� can be introduced by improper handling
and/or installation of plumbing
� a common cause of column stationaryphase degradation
� can damage instrument
Oxygen� most common contaminant
� a common cause of column stationaryphase and inlet liner degradation
� can cause decomposition of labileanalytes
� opportunity for introduction at everyfitting present in the gas line or duringuse of wrong tubing (i.e., gas permeable)
In some cases it may be difficult todetermine which contaminant presents the biggest problem in a given analysis. Ifunsure, a call to your gas supplier may behelpful. Once the problem contaminantshave been identified and a generalcontaminant level is determined, the nextstep is to choose a gas purity level thatcomes closest to these requirements.
Keep in mind that higher grades of gasgenerally cost more. The greatest costsavings can be achieved by using thelowest purity gas which will neitherinterfere with the analysis nor damage your equipment. Using the proper gaspurification equipment to remove commoncontaminants and achieve the desiredpurity level is essential.
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GAS MANAGEMENT
Agilent brings the highest performance and largest variety of gas purifiers (traps) to gas chromatographers. Purifiers areavailable in a variety of sizes andconfigurations, to remove commoncontaminants like oxygen, moisture, and hydrocarbons. In-line gas purifiers,including refillable, indicating, S-shaped,and metal body types, are made to removespecific contaminants. Agilent also offersgas purification systems with removablecartridges. These systems provide theability to design the right combination of filters needed for your application toachieve the proper gas purity.
The illustration on the next page shows the most common gas purificationconfigurations used in gas chromatography.
Regardless of which purification system is employed, proper installation andmaintenance is required to achieve optimal performance from the purificationsystem(s). A purifier that is not maintainedwill eventually saturate and becomeineffective, or worse, a source ofcontamination.
Other Considerations� determine desired purity level
� keep number of “breaks” in gas line to a minimum
� install purifiers in a convenient locationclose to the GC
� purifier log books are useful fordetermining maintenance schedule
� use indicating traps closest to the GC soyou can determine when to change thetraps that are upstream
Gas Purification Systems
Contaminants & Purities
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Gas Traps
The purpose of gas traps is to removedetrimental impurities from the carrier and detector gases. Moisture (water),oxygen and hydrocarbon traps are the most common traps used with GC systems. A few combination traps areavailable which remove moisture, oxygenand/or organics with a single trap. Theeffectiveness of the traps depends on theinitial quality of the gas. Little enhancementby traps to the GC system is obtained bytraps when using very high purity gases(e.g., ultra-high purity or similar grades)while obvious improvement is obtained with lower grades of gas.
Constant exposure of capillary columns tooxygen and moisture, especially at hightemperatures, results in rapid and severecolumn damage. The use of oxygen andmoisture traps for the carrier gas mayextend column life and protect theinstrument. Traps may provide someprotection if there is a leak at or around the gas cylinder. Any moisture or oxygenintroduced into the gas stream due to theleak will be removed by the trap until itexpires. This creates an opportunity todetect and fix the leak before column orinstrument damage occurs.
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GAS MANAGEMENT
Carrier Gas Purification
Key:1 = Moisture Trap2 = Hydrocarbon Trap3 = Oxygen Trap4 = Indicating Oxygen Trap5 = Gas Purification System6 = Combination Trap for
moisture, oxygen, andhydrocarbon removal
Detector Gas Purification
In-Line Gas Purifiers
Gas Purification System
Combination Trap
-OR-
-OR-
FID make-up, air,and H2
Gas supply
Gas supply
Gas supply = cylinder, in-house line, or gas generator
Regulator = Brass dual stage regulator
Vent
ECD make-up
ELCD reaction gas
MS carrier gas
Moisture (Water) Traps
There are several different adsorbents and indicating materials used in moisturetraps. Moisture traps can be easily refilled. Adsorbent refills are typically 1/4 to 1/2 the cost of a new trap makingrefilling a more economical (and lesswasteful) option.
Indicating moisture traps are available inplastic and glass bodies. Glass body trapsare used when potential contaminants from plastic trap bodies are a concern.Glass traps are normally encased in aprotective, plastic shrink wrap or a highimpact plastic shield (outer trap body).Glass and plastic bodied traps are usuallypressure tested at 150 psi, thus they aresafe for use at the typical pressuresrequired by the GC.
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GAS MANAGEMENT
Only a small sampling of gas purifiers are shown here. For a complete selection of gas purifiers, see the Gas Purifier Selection Guide in the Agilent 2002-2003 Chromatography & Spectroscopy Supplies Reference Guide.
Refillable Glass Moisture Trap
Moisture S-Trap Big Moisture TrapRefillable Moisture Trap
Size H2O Removal Maximum Effluent H2O 1/8 in. 1/4 in.Description (cc) Capacity (g) Concentration (ppb) Part No. Part No.
Molecular Sieve 13X and Indicating 4Å – Economy, with plastic Lexan body (other packings available, see Agilent catalog)
Refillable Moisture Trap 200 36 18 MT200-2 MT200-4
Adsorbent Refill (1 pint) for MT Series MSR-1 MSR-1
Glass Indicating Moisture Traps (larger size is available, see Agilent catalog)
Glass Indicating Moisture Traps 100 16.3 6 GMT-2-HP GMT-4-HP
Molecular Sieve Refill for GMT Series 250 GMSR GMSR
Moisture Removal S-Trap – can be reconditioned in the GC oven
Moisture S-Trap – preconditioned 5060-9084
Big Moisture Traps – for the Ultimate Moisture Capacity
Big Moisture Trap 750 BMT-2 BMT-4
Refill for BMT Series (2 refills) BMSR-1 BMSR-1
Moisture Removal Traps
Hydrocarbon Traps
Hydrocarbon traps remove organics, suchas hydrocarbons and halocarbons, from the gas stream. The adsorbent is usuallyactivated carbon or an impregnated carbonfilter media. Carbon removes organicsolvents from the gas stream, including thetypical solvents used in nearly every lab.Hydrocarbon-moisture combination trapsare also available which remove water in
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GAS MANAGEMENT
1/8 in. 1/4 in.Description Size (cc) Part No. Part No.
Hydrocarbon Traps – General Purpose
Refillable Hydrocarbon Trap 200 HT200-2 HT200-4
Adsorbent Refill (1 pint, 2 refills) ACR ACR
Big Hydrocarbon Traps – for the Ultimate Hydrocarbon Capacity
Big Hydrocarbon Trap 750 BHT-2 BHT-4
Refill for Big Hydrocarbon Trap (2 refills) BACR BACR
Hydrocarbon Removal S-Trap – can be reconditioned in the GC oven
Hydrocarbon S-Trap 5060-9096
Capillary Grade Hydrocarbon Traps – for crucial capillary applications
Capillary Grade Hydrocarbon Trap 100 HT3-2 HT3-4
Adsorbent Refill (1 pint, 3 refills) ACR ACR
Hydrocarbon Traps
Oxygen Traps
Oxygen traps usually contain a metal-containing inert support reagent. Mostoxygen traps reduce the oxygenconcentration to below 15-20 ppb. Thecapacity of a standard oxygen trap isapproximately 30mg of oxygen per 100cc of trap volume. Oxygen traps can removesome small organics and sulfur compoundsfrom gas streams.
Metal (usually aluminum) trap bodies arerecommended for GC analyses. Some
plastics are permeable to air and containcontaminants that can degrade gas quality.In addition, many of the metal bodiedoxygen traps can withstand high pressures(up to 2000 psi). Some oxygen traps alsoremove moisture from the gas streamwithout affecting the oxygen removalcapability.
Indicating oxygen traps change color whenoxygen is present in the gas at harmfullevels. Indicating traps are not intended tobe the primary oxygen removal trap, butshould be used in conjunction with a highcapacity non-indicating oxygen trap. Theyare installed after the high capacity oxygentrap in the gas line to indicate when thehigh capacity trap is expired and needs tobe changed. Expired oxygen traps need tobe immediately changed since they cancontaminate the gas, in addition to failingto remove oxygen.
1/8 in. 1/4 in.Description Size (cc) Part No. Part No.
Indicating Oxygen Traps – glass body with plastic safety shield
Indicating Oxygen Trap 30 IOT-2-HP IOT-4-HP
Big Oxygen Traps – non-indicating, for the Ultimate Oxygen Capacity (smaller sizeavailable, see Agilent catalog)
Big Oxygen Trap 750 BOT-2 BOT-4
Oxygen Traps
Big Oxygen Trap
Indicating Oxygen Trap
Hydrocarbon Trap
Only a small sampling of gas purifiers are shown here. For a complete selection of gas purifiers, see the Gas Purifier Selection Guide in the Agilent 2002-2003 Chromatography & Spectroscopy Supplies Reference Guide. www.agilent.com/chem 9
GAS MANAGEMENT
1/8 in. 1/4 in.Description Size (cc) Part No. Part No.
Oxygen/Moisture Traps
Agilent OT3 Trap 100 OT3-2 OT3-4
Hydrocarbon/Moisture Traps
Refillable Hydro-Moisture Trap 200 HMT200-2 HMT200-4
Refill for Hydrocarbon/Moisture Trap (1 pint, 2 refills) HCRMS HCRMS
Big Universal Traps – for the Ultimate in Gas Purification, removes oxygen, moisture,hydrocarbons, CO, and CO2
Big Universal Trap – Helium purged (also recommended for GC Mass Spec) 750 RMSH-2 RMSH-4
Big Universal Trap – Hydrogen purged 750 RMSHY-2 RMSHY-4
Big Universal Trap – Nitrogen purged 750 RMSN-2 RMSN-4
Big Mounting Clip for mounting Big Traps 2/pk UMC-5-2 UMC-5-2
Combination Traps
Agilent carries several Combination Trapsthat provide multiple contaminant removalin a single trap. These traps offer:
� Optimized adsorbents for maximumsurface area and capacity
Hydrocarbon Moisture Trap
Big Universal Trap
Hydrocarbon Traps continued
addition to organics as described in the nextsection. Capillary grade hydrocarbon trapsare purged with ultra-high purity helium and packed with a very efficient activatedcarbon material. Metal trap bodies are usedto prevent any contaminants in plastic trapbodies from contaminating the carbonadsorbent. Most hydrocarbon traps can be refilled by the end user.
Big Hydrocarbon Trap
Hydrocarbon S-Trap
� Leak-free, one-piece design to eliminatepotential leaks from using multiple traps
� Efficient design which preventschanneling and promotes efficientscrubbing
� The ultimate in purification with a singletrap (Big Universal Trap)
Agilent OT3 Trap
High Capacity
Gas Purification System
Three Cartridge System� Agilent’s highest capacity and most
economical gas purification system.
� Provides low-cost gas contaminantremoval for up to 18 cylinders of carrier gas.
� Includes a manifold with cartridgemounts and three replaceable cartridges:one moisture/hydrocarbon cartridge; oneoxygen cartridge; and one oxygenindicating cartridge.
� Consists of a permanent all-weldedstainless steel manifold to minimize the potential for leaks.
� Suitable for bench or wall mounting.
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GAS MANAGEMENT
Description Part No.
Three Cartridge System—Includes manifold for wall or bench mount and 3 cartridges (H2O/hydrocarbon, oxygen, and indicating O2)
With 1/8 in. fittings 5183-1907
With 1/4 in. fittings 5182-9776
Replacement Cartridge Kit—Includes all three cartridges for 5182-9780above system.
Single Cartridge System—Includes single cartridge manifold brackets for wall or bench mount, and a triple combination cartridge (H2O/hydrocarbon, and O2 )
With 1/8 in. fittings 5183-4598
With 1/4 in. fittings 5183-4599
Triple combination replacement cartridge for single cartridge system 5183-4600
High Capacity Gas Purification System
Three Cartridge High Capacity
Gas PurificationSystem
Single-Cartridge System� Contains a triple-combination cartridge
that offers the same highly efficientcontaminant removal properties fromeight cylinders of carrier gas but withoutthe visual indicator.
� Other cartridges are also available fordetector gas supplies and as individualfilters for specialized requirements.
Description Fitting (in.) Part No.
4-Head
O2, indicating O2, HC, H2O 1/8 RQC-P
Quick Change Plus (QC+) — Point of Operation Panels
Description Part No.
High capacity oxygen GC-1
High capacity moisture GC-2
Indicating moisture GC-2-I
Hydrocarbon GC-3
Indicating oxygen GC-4
Replacement Cartridges
Only a small sampling of gas purifiers are shown here. For a complete selection of gas purifiers, see the Gas Purifier Selection Guide in the Agilent 2002-2003 Chromatography & Spectroscopy Supplies Reference Guide. www.agilent.com/chem 11
GAS MANAGEMENT
QC+ Point of Operation Panel
The QC+ Point of Operation Panel containspurifier cartridges that can be quicklychanged. The cartridges are removed fromthe panel without interruption of gas flowto the system, drastically minimizing costlyinstrument downtime.
Filter cartridges are of all metal or glassconstruction, eliminating infusion andresultant signal noise associated withfilters constructed from plastics. Cartridgesare quickly installed via a simple knurledretaining nut, with no wrenches needed. Asmany as four cartridges can be replaced ina matter of seconds, and because there islow dead volume, a minimal amount of gassystem purge is required after installation.
RQC-P
NEED MORE HELP?
Tap Agilent’s GC knowledge over the phone, on-line, in theclassroom, even at your site. See pages 56-58 for moreinformation about our experttraining, service and support.
Only a small sampling of gas purifiers are shown here. For a complete selection of gas purifiers, see the Gas Purifier Selection Guide in the Agilent 2002-2003 Chromatography & Spectroscopy Supplies Reference Guide.
Universal/External Split Vent Trap
Split vent traps stop environmentalpollution. The split vent trap was designedto protect the lab environment from thecontaminants released by split injectionsystems, which can vent up to 500 timesthe amount of sample reaching thedetector into the laboratory's air. Areplaceable, impregnated carbon filtermedia traps and eliminates a broad rangeof contaminants. The traps are also easy to change and come with three packs ofreplacement cartridges each. Replaceapproximately every six months.
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GAS MANAGEMENT
Description Part No.
Universal/external split vent trap with 3 cartridges(1/8 in. Swagelok fitting) RDT-1020
Replacement cartridges (3/pk) RDT-1023
Description Part No.
Carrier Gas Purification System: Single position system perfect for GC/MS, ECD and NPD detectors. Includes the triple filter cartridge. 5182-9704
Super-Clean Gas Purification System: For your most demanding GC application, includes four position baseplate manifold with four filter cartridges: oxygen, moisture (both with indicator), and two hydrocarbon cartridges. 5182-0816
Replacement Filter Cartridges
Triple Filter Cartridge: A single carrier gas filter now with hydro-carbon, moisture, and oxygen trapping capability. Includes moisture and oxygen indicator so you know exactly when to replace the cartridge. 5182-9705
Filter cartridge bundle of 4 (oxygen, moisture, and 2 hydrocarbon) 5183-4770
Super-Clean Gas Purification SystemsAvailable with 1/8” fittings only
Split Vent Trap and Cartridges
Super-Clean Gas Filter System
Super-Clean gas filter systems aredesigned to provide the utmost inconvenience and contamination reduction. The system is tested for leak-tightness and the glass and metalconstruction of the cartridges eliminatesdiffusion of contaminants into the gasstream. During cartridge replacement,check valves close off the system to theatmosphere, further minimizing the entry of contaminants.
Brass Body Regulator
Regulators
Pressure regulators are an integralcomponent in any gas handling system.Their function is to reduce the pressurefrom a high pressure source, such as acylinder, to a suitable use pressure.Although regulators are very good atcontrolling pressure, they do not controlflow. They have a maximum flow ratewhich is dictated by the design. Basically,the flow is determined by the pressure drop across the regulator.
Types of Regulators
There are primarily two types of regulators: single stage and dual (or two)stage. The difference is that a dual stageregulator is actually two regulatorsconnected in a series.
Dual stage regulators provide more preciseand consistent pressure control than singlestage regulators. The reason is that in asingle stage regulator, as the gas cylinder
empties and the inlet pressure to theregulator decreases (inlet decay), thepressure on the diaphragm is reduced.Without proper adjustment, the outletpressure might slowly rise.
A dual stage regulator overcomes thisproblem by connecting two regulatorstogether. The first stage regulates thepressure to the second stage thus creatinga constant pressure and allowing minimalinlet decay. Agilent recommends usingtwo-stage regulators with our GC Systemsto provide the proper pressure control foroptimal use.
Regulator Materials
Regulators are usually constructed of brassor stainless steel. The choice of materialfollows the same guidelines as the choiceof tubing. Generally, it is not recommendedthat the materials be interchanged. Ifstainless steel tubing were chosen due
to purity considerations, then a stainlesssteel regulator should be chosen for thesame reasons. Unfortunately, use of highpurity stainless steel regulators is oftencost-prohibitive.
No matter which material is chosen for theregulator body, be sure to specify one withstainless steel diaphragms for criticalapplications such as use on carrier, fuel ordetector gases. Agilent recommends usingour economical brass body, dual stainlesssteel diaphragm regulators for most GCapplications. These regulators, combinedwith the proper gas purification system,provide proper gas pressure control andpurity for gas chromatography.
When ordering a regulator, be sure tospecify the proper connections. In the US, most gas manufacturers follow CGAconnection guidelines. In Europe, there are a number of organizations designatingcylinder connections that are specific toindividual countries. It is best to contactyour local supplier for the properconnection designation.
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GAS MANAGEMENT
Description Part No.
Brass Body, Dual Stainless Steel Diaphragms (1/8 in.)*
CGA 346, 125 psig max (8.6 bar), Air 5183-4641
CGA 350, 125 psig max (8.6 bar), H2, Ar/Me 5183-4642
CGA 540, 125 psig max (8.6 bar), O2 5183-4643
CGA 580, 125 psig max (8.6 bar), He, Ar, N2 5183-4644
CGA 590, 125 psig max (8.6 bar), Air 5183-4645
*For 1/4 in. tubing, purchase a 1/4 in. adapter listed below
Regulator Outlet Adapters — Female NPT to Swagelok-style
1/4 in. to 1/8 in. brass (included with brass regulators) 0100-0118
1/4 in. to 1/4 in. brass* 0100-0119
*Required for plumbing 1/4 in. tubing to regulators above
HELPFUL HINT: Always depressurize a regulator before closing the adjustingknob and removing the regulator from the cylinder.
Description Part No.
Copper tubing, 1/8 in., 50 ft. 5180-4196
Copper tubing, 1/8 in., 12 ft. 5021-7107
Tubing—Precleaned
Tubing
When constructing or maintaining a gasdelivery system for GC, choosing the propertubing material is very important and willhelp to eliminate potential problems andimprove the overall quality of the gassystem. Although there are many commontubing materials available, some posesafety or cleanliness problems.
Non-metallic types of tubing such aspolyethylene and Teflon are notrecommended for GC applications due to their gas permeability and difficulty in cleaning. This type of tubing can be
used for non-critical applications, such aspressurizing pneumatic lines; however, beaware of its pressure limitations.
In view of these problems, the list ofappropriate tubing materials has beennarrowed down to two: copper andstainless steel. Agilent recommends usingcopper tubing for most applications, since it is easy to bend and plumb and is lessexpensive than stainless steel. Usestainless steel tubing only for crucialapplications that require very high purity.
Cleaning Tubing
Before any tubing is placed into service, or if it becomes contaminated with use, it is essential that it be properly cleaned.Unclean or improperly cleaned tubing canlead to contamination of the system withdisastrous results.
Cleaning tubing requires the use of suitabledetergents and solvents along withnitrogen and a purgeable oven for drying.This may be done easily for small lengths of tubing but in larger systems, thecleaning procedure becomes unwieldysometimes, leaving behind a large quantityof solvent requiring proper disposal.
Fortunately, Agilent provides clean highquality GC grade tubing for large systemsas an economical alternative.
HELPFUL HINT: Always replace cylinders ataround 500 psi, to reduce the risk of havinga drastic pressure drop right in the middleof an important analysis.
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GAS MANAGEMENT
Tubing Type Diameter Recommended Pressure Drop(inches) Max. Length (feet) (psig)
Copper 1/8* 50 2
Copper 1/4* 300 0.5
*Recommended when multiple instruments are connected to the same source
Determining Tubing LengthParameters: 2000sccm (4.2 scfh); Temperature: 70˚F; Pressure 30 psig
Spectra-Link Tubing Connecting Systemon a two-stage regulator
Gas Leak Detector
Leak Detection
Leaks allow oxygen and othercontaminants to enter the gas stream.Therefore, GC instrument maintenanceshould include checking fittings andconnections with a gas leak detector.Agilent’s Gas Leak Detector enables quick
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GAS MANAGEMENT
Description Part No.
Leak detector includes probe, extended flexible probe, range extension nozzle,probe clip and template, cable, AC power adapter/battery charger, battery, usermanual, cleaning wipe, and carrying case (available in 115 V or 220 V).
Gas leak detector, 115 V 5182-9646
Gas leak detector, 220 V 5182-9648
Description Part No.
Cylinder wall bracket with strap and chain 5183-1941(cylinder size up to 14 in., 35 cm)
Cylinder Bracket
Description Part No.
Spectra-Link with 1/8 in. fittings and 36 in. SS tubing SL-8
Spectra-Link with 1/4 in. fittings and 36 in. SS tubing SL-4
Spectra-Link is No Ordinary Flexible Tubing!
� Stainless Steel: no outgassing or permeation through polymeric materials� Quick Connection: prevents air from entering gas lines during tank changeover� Tested: each system has leak rates lower than 1x10-5 cc/sec
Gas Leak Detector Kit
and easy detection and measurement ofgas leaks for 12 common gases. Based on adual cell micro volume thermal conductivitysystem, this unit provides very highsensitivity and eliminates contaminationcaused by soap solution methods.
Cylinder Wall Bracket
ADM 1000 features include:
� Accuracy ± 3%
� Operating temperature range—0 to 45ºC for the instrument, -70 to 135ºC for the tubing
� Calibration—traceable to NIST primarystandards
� Real time, split ratio measurement
� CE mark certified
� Measures flow rates from 0.5 to 1000 mL/min
� Split ratios—compare the ratio from one gas measurement to another (i.e., injection port split ratios)
ADM 2000
In addition to the features of the ADM1000, the ADM 2000 includes:
� Mass flow measurements—measureflow rate, independent of atmosphericpressure and temperature (calculated)
� Data output through RS-232 port
� 9V battery and AC power adapter (120 or 220 VAC)
Selecting a Flowmeter
Agilent manufactures the largest selectionof volumetric and mass flowmeters forchromatography. We have developedflowmeters for measuring capillary columnflows, calibrating air pumps and flowcontrollers, and verifying instrument gasflows. All flowmeters are calibrated toNIST-traceable standards.
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GAS MANAGEMENT
Description Part No.
FlowTracker 1000 Flowmeter 5183-4779
FlowTracker 2000 Flowmeter and Leak Detector 5183-4780
FlowTracker Universal AC Adapter (optional, not supplied with FlowTracker units) 5183-4781
FlowTracker Flowmeters – volumetric, multimode flowmeters
Flow Rates
Setting and maintaining GC flow ratesgreatly affect the instrument accuracy and sensitivity. During maintenance, verify carrier and support gas flows with the proper flowmeter. Choosing aflowmeter for your application dependsupon measurement speed, ease of use,accuracy, and flow rate range.
FlowTracker 2000
ADM 1000
ADM 2000
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Only a small sampling of flowmeters are shown here. For a complete selection of flowmeters, see the Flowmeter Selection Guide in the Agilent 2002-2003 Chromatography & Spectroscopy Supplies Reference Guide. www.agilent.com/chem 17
GAS MANAGEMENT
Flow Rate (mL/min) Gases Accuracy Power RS-232 DataDescription Low High Measured (%) Supply Output Part No.
ADM Flowmeters – volumetric, measures all gases*
ADM1000 0.5 1000 All ± 3 9V Battery None 220-1170
ADM2000 0.5 1000 All ± 3 Battery or 120 VAC Yes 220-1171-U
ADM2000E 0.5 1000 All ± 3 Battery or 220 VAC Yes 220-1171-E
Electronic Mass Flowmeter – dedicated mass flowmeter, very accurate for specific gases*
Veri-Flow 500 He, H2, Ar/CH4 Rechargeable Battery(110 V) 5.0 500 N2, Air ± 3 or 110 VAC Yes HVF-500
Veri-Flow 500 He, H2, Ar/CH4 Rechargeable Battery(220 V) 5.0 500 N2, Air ± 3 or 220 VAC Yes HVF-500-2
Optiflow Flowmeters Gas Flowmeters – versatile volumetric flowmeters**
Optiflow 420 0.1 50 All +/- 3 9V Battery None HFM-420
Optiflow 570 0.5 700 All +/- 3 9V Battery None HFM-570
Optiflow 650 5.0 5,000 All +/- 2 9V Battery None HFM-650
*non-corrosive gases only
**non-corrosive and mildly corrosive gases only
Flowmeters
Optiflow 420Veri-Flow 500
There’s More!
Agilent offers a series of free Maintenance Guides for your GC System.
Successful chromatography depends on optimum
performance from every component of the GC system.
At Agilent, we want to help you keep your system running
at peak performance. We want to share our 35 years’
experience in chromatography to help you maximize your
investment. This new GC System Maintenance Guide is just
one in a series of system support literature from Agilent,
designed to help you optimize the performance of your
GC system. Other Guides include:
GC Inlet Resource Guide (publication # 5988-3466)
This 24-page Guide offers troubleshooting tips for all components
of the GC inlet, including septa, ferrules, and liners.
Maintaining Your GC/MS System (publication # 5988-3960)
This 48-page Guide covers everything from maintaining a Mass
Selective Detector, to GC/MS columns and supplies, to GC/MS
support services.
Developed by Agilent GC and GC/MS experts, these Guides
are packed with system operation and maintenance
recommendations, repair tips, and easy ordering information
for PerfectFit parts and supplies. For a copy of these Guides,
visit www.agilent.com/chem, call 800-227-9770 (in US), or
contact your authorized Agilent distributor.
Only a small sampling of vials and syringes are shown here. For a complete selection of vials and syringes, see the Agilent 2002-2003 Chromatography & Spectroscopy Supplies Reference Guide.
“Good sample introduction helpsensure good reproducibility, optimal
peak shape, and accurate sampledelivery. Agilent’s commitment to
offering the highest quality suppliesmeans accurate, reliable results.
Time after time.”
Bryan Bente, Ph.D.Technology Development Manager
Sample Introduction & Inlets
Agilent offers a wide range of GC samplevials, septa, syringes, liners and inlets for a broad range of gas-phase applications.Our PerfectFit supplies have been designedspecifically for Agilent instruments so they help to ensure GC results that arereproducible and accurate. This sectionreviews these critical components, andhelps you make the right choice. Also, lookfor useful information from proper syringeuse and cleaning techniques to a detaileddiscussion on optimized inlet settings. Allto make your GC analysis easier. All fromthe GC experts.
www.agilent.com/chem 19
Sample Introduction
Vials
Agilent wide opening vials are a perfect fitfor analyzing samples with your GC. Theyhave specially designed vial neck angles,bottom design and height to ensurecompatibility with Agilent autosamplerswith rotating or robotic arm trays. Agilentoffers a large variety of autosampler vials in different closures, cap colors, septachoices and package options. Agilent alsooffers convenience packs with 500 vialsand caps in a reusable blue storage box.
For small sample sizes, Agilent offers avariety of options. You can use microvolumeinserts with the wide opening vials or, foradded convenience, use vials with smallvolume capacity.
Vial Filling
When filling sample vials, keep in mind:
� if you need to test a large amount ofsample over repeated injections, dividethe sample among several vials to obtainreliable results
� when sample volume in the vial is low,contaminants from the previous sampleinjection or solvent washes may have agreater impact on the sample.
The airspace in the vial is necessary toavoid forming a vacuum when sample iswithdrawn. This could affectreproducibility.
20 www.agilent.com/chem
SAMPLE INTRODUCTION & INLETS
HELPFUL HINT: Do not inject air into thevials to prevent the vacuum. This oftendamages the cap seal.
Glass—for general purposeuse and for use with acids
Silanized—for use withsamples that bind to glass,and for trace analyses
Polypropylene—for usewith alcohols and aqueoussolvents
Amber Vials—for use withlight-sensitive samples
Microvolume Inserts—for use with very smallsample volumes
High Recovery Vials—for use with limited samplevolumes
Recommended fill volumes for sample vials
Vial Options
3.6 mm*
*Needle position based on standard sampling depth.
1 mL 50 µL
100 µL vial
Selecting Vial Septa Materials
Vial cap septa are critically important to optimal analysis. Each septumcomplements the overall system andenhances chemical performance. Agilent vial cap septa are specificallyformulated and constructed for optimumsystem performance, with minimal coringand superior chemical inertness.
Red Rubber/Teflon� Routine analysis� Moderate resealing� Excellent chemical inertness� Not recommended for multiple
injections or storage of samples� Least expensive
Silicone/Teflon� Excellent resealing� Resists coring� Good for multiple injections
Teflon/Silicone/Teflon� Used in trace analysis applications� Above average resealing� Most resistant to coring� Least evaporation� Use with large diameter, blunt tip
syringe needles
Teflon Disc� Good for MS and ECD analysis� Chemically inert� No resealing� Single injection� No long-term sampling storage
Viton� Chlorinated solvents� Organic acids� Limited resealing� Not suitable for 32 gauge syringe
Determining Your Quantity Needs
To determine potential septa orderingquantities, consider:
� the number of samples run during aday/week
� if samples are run in small or largebatches
� if samples are run manually or with anautosampler
� if samples are run overnight, unattended
www.agilent.com/chem 21
SAMPLE INTRODUCTION & INLETS
Description Quantity Part No.
Vials
2 mL Crimp top vial convenience pack with silver AI caps with Teflon/Red rubber septa 500/pk 5181-3400
2 mL Screw top vial conveniencepack with blue screw caps andTeflon/Red rubber septa 500/pk 5182-0732
2 mL Snap top vial convenience packwith clear polypropylene snap capsand Teflon/Red rubber septa 500/pk 5182-0547
100 µL Insert for wide opening vials 100/pk 5181-1270
300 µL Polypropylene vials 1000/pk 9301-0978
100 µL Glass lined polypropylene vials 100/pk 9301-0977
15 µL reservoir volume, Micro-V vial,clear crimp top 100/pk 5184-3551
30 µL reservoir volume, High recoveryvial, crimp top 100/pk 5182-3454
Vials
HELPFUL HINT: Unattended autosamplerruns require a precise fit for uninterruptedoperation. Typically, automated sample runsuse a higher quality and quantity of vials.
NEED MORE HELP?
Tap Agilent’s GC knowledge over the phone, on-line, in theclassroom, even at your site. See pages 56-58 for moreinformation about our experttraining, service and support.
Syringes
Syringe type and design are important forchromatography to ensure reproduciblesample injections for consistent results.The Agilent line of syringes are a perfect fitwith your autosamplers and come with avariety of plunger and needle choices.
PerfectFit means they are designed:� for reproducible sample volume delivery� specifically for the Agilent inlet or
autosampler� to maximize inlet septum lifetime
Selecting Syringes
1. Select the syringe type based on the inlet (injection port) you are using andthe volume of sample you want to inject.
2. Select a syringe. Refer to your automaticliquid sampler operating documentationfor available syringe sizes andcorresponding injection volumes.
3. Select the appropriate syringe needle gauge.
22 www.agilent.com/chem
SAMPLE INTRODUCTION & INLETS
Inlet Needle Gauge Column Type
Packed, split orsplitless (including PTV) 23 gauge or 23/26 gauge tapered any applicable
Cool on-column 23/26 gauge tapered or 26 gauge 530 µm
Cool on-column 26/32 gauge tapered 320 µm
Cool on-column 26/32 gauge tapered 250 µm
Needle Gauge Selection
Sharp tip
Use syringe needles with an Agilent dual-taper needle or a conical tip. Sharp-tippedneedles tend to tear the inlet septum andcause leaks. Also, a sharp-tipped needletends to leave residual amounts of sampleon the septum as it exits, resulting in alarge solvent tail on the chromatogram.
Tapered needle
Cone tip
Needle tips
Needle ShapeNeedle Tip
HELPFUL HINT: Failure to use an on-column syringe when injecting into an on-column inlet could damage theinjector, syringe and column.
www.agilent.com/chem 23
Syringe Advantage Limitations Recommended Use
5 µL, fitted • Most accurate • Thinnest plunger, • 1 µL injectionsplunger syringe for 1µL can bend • Clean samples
injection more easily • Routine analysis• No hardware • Not ideal for higher
modification needed viscosity samplesfor 0.5 µL injection • Plunger not
replaceable
10 µL, fitted • Most economical • Most accurate only • General purposeplunger • Most reliable fitted for 2 µL and larger syringe
plunger syringe injections • Clean samples• Less bending • Plunger not • Routine analysis• Better for high replaceable
viscosity samples
10 µL, • Replaceable plunger • More expensive • Dirty samplesgas-tight for reduced than fitted plunger • Gases and volatile
repair cost • Not available in samples• Less plunger binding 5 µL size • Reactive samples
than fitted plunger• Tight seal between
plunger and barrel
SAMPLE INTRODUCTION & INLETS
Syringe Characteristics and Recommended Uses
To insert a needle into a syringe barrel:
1. Unscrew the syringe barrel cap andremove the spring.
2. Make sure the needle has the Teflondisk. If the syringe barrel does not have the Teflon disk, use the instructionsin the syringe box to wrap the needleyourself.
3. Slide the spring and the cap down overthe needle.
4. Insert the needle into the syringe barrel.
5. Screw the cap back on the syringe barrel.
Replacing On-column Syringe Needles
The stainless steel needles used for 250-µm and 320-µm injections must be inserted into a glass syringe barrel.Select the correct size needle for thecolumn you plan to use.
To view a video on syringe installation, visitwww.agilent.com/chem/supplies, click on
“How-to Video” under the Reference Library.
Syringe Tips
� Make sure to input the proper syringesize when setting up the injection sectionof your data handling device.
� Rinse syringes and clean their plungersbefore use to maximize syringe lifetime.
� Rinse the syringe 5-8 times betweeninjections to minimize sample carryover.
� Pump sample in and out of the syringe atleast 5 times to remove any air bubbles,and for maximum reproducibility andaccuracy.
� A 26 gauge syringe can be used for on-column injections into a 0.53mm idcolumn. Always check that on-columnsyringe needles fit inside the capillarycolumn before installing the column andsyringe in the GC.
� For on-column injections, always use theproper septum nut and stainless steelinsert for the column dimension you areusing. Use a septum with a moldedthrough-hole with injections onto 0.32mmand 0.25mm columns.
� Remove a gas-tight plunger from thesyringe for long-term storage to keep theTeflon tip leak-free. If a gas-tight plungerdoes not fit properly, place it in hot waterfor about 10 minutes then press the tipuniformly on a clean, hard surface and letcool to room temperature. The plungershould reseal correctly to provide 10-25%more injections.
24 www.agilent.com/chem
SAMPLE INTRODUCTION & INLETS
� To maximize the lifetime of standardplungers, rinse the syringe and wipe theplunger with solvent (isopropanol oracetone) and a lint-free wipe, as specifiedin the syringe cleaning procedureincluded with each syringe.
Only a small sampling of vials and syringes are shown here. For a complete selection of vials and syringes, see the Agilent 2002-2003 Chromatography & Spectroscopy Supplies Reference Guide. www.agilent.com/chem 25
SAMPLE INTRODUCTION & INLETS
Description Unit Part No.
Miscellaneous Autosampler Supplies
4 mL wash vial with screw caps 144/pk 9301-0723
Diffusion caps for 4 mL vials 12/pk 07673-40180
Septa for 4 mL vial 144/pk 9301-1031
4 mL wash vial with fill marking, caps 25/pk 5182-0551
Screw for mounting syringe 07673-20570
Quadrant kit (4 tray sections) 18596-40015
7673 Basic Supply Kit contains: 10 mL syringes (6/ea), 23/26 gauge needles, 4 mL vials with diffusion caps (144/pk), 2 mL automatic sampler vials with screw caps (1,000/pk), GC septa (25/pk), Vial racks (5/pk) 07673-60840
Automatic Liquid Sampler Supplies
Description Gauge Quantity Part No.
Tapered Needle Syringes(use for split/splitless or on-column injections with 0.53 mm id columns)
10 µL Tapered Fixed Needle 23-26s/42 6/pk 5181-3360
5 µL Tapered Fixed Needle 23-26s/42 6/pk 5181-8810
Straight Needle Syringes(use with Merlin Microseal)
10 µL Straight Fixed Needle 23/42 6/pk 9301-0725
5 µL Straight Fixed Needle 23/42 6/pk 5182-0875
Syringes
LeaksSince packed-column inlets are usuallyflow-controlled, septum and column leakswill have a direct impact on retention timesand peak areas. Sample can be lost throughthe leak holes, and air can diffuse back intothe inlet to cause column degradation.Change the septum on a regular basis andcheck column connections at the first stageof problems. To prevent stationary phasedecomposition, make sure that the ovenand inlet are at room temperature when notin use and when changing the septum.
Packed-Column Inlets
Packed-column direct inlets are verypopular. Packed-column analysis isfrequently done when high efficiencyseparations are not needed or when gasesare analyzed by gas-solid chromatography.Packed column inlets are simple in bothdesign and use. Few parameters need to beset, and all carrier gas flow flushes throughthe inlet into the column in the standardconfiguration.
26 www.agilent.com/chem
Parameter Selection/Setting Rationale
Inlet temperature BP of solvent +50˚C Ensures flash vaporizationBP of major solute(s) Use for neat samples
Insert type 1/8-inch stainless steel Use for ss column only1/4-inch stainless steel Inserts permit connection of
columns up to 1/4-inch od.
Liner Glass Use to lower activity (replaceable)
Initial column temperature programming Sharpens peaks and temperature reduces run time
Column type 1/8-inch packed stainless Will not break1/4-inch packed glass Better for polar or labile
compounds
Carrier gas flow 20-40 mL/min Use with N2 carrier gas30-60 mL/min Use with He or
H2 carrier gas
SAMPLE INTRODUCTION & INLETS
Packed-Column Inlet Procedures/Practices
Troubleshooting
Most problems with packed-column inletsinvolve sample decomposition, flashback,or leaks.
DecompositionSince packed-column inlets are active,especially if glass liners are not used, polarsample components will often tail ordegrade in the inlet. Sample decompositioncaused by the inlet is easily diagnosed; thedecomposition products will have peaks atthe same retention times as standards forthe decomposition product.
When inlet-caused decomposition issuspected, try intracolumn direct injection,deactivated glass liners, or lower inlettemperatures, and remove any columnpacking in the inlet zone.
The inherent activity of packed-columninlets is somewhat mediated by the factthat they usually have low internal volume.When this is coupled with the relativelyfast flow rates used with packed columns,the residence time of sample in the inlet isshort and decomposition is reduced incomparison to the decomposition thatoccurs with some capillary inlets (forexample, splitless inlets).
FlashbackThe negative side of low inlet volume,however, means that excessively largesample injections will easily exceed thecapacity of the liner and will flash back intogas supply lines and onto the septum. Thiscan cause several maladies, includingghost peaks, sample losses, irreproduciblepeak areas, and decomposition.
NEED MORE HELP?
Tap Agilent’s GC knowledge over the phone, on-line, in theclassroom, even at your site. See pages 56-58 for moreinformation about our experttraining, service and support.
www.agilent.com/chem 27
Item Description Unit Part No.
1 Septum nut 18740-60835
2 Septa Bleed temperature, optimized, 11 mm** 50/pk 5183-4757
3 Top insert weldment 19243-80570
4 Viton O-rings 12/pk 5080-8898
5 Glass liner, disposable 25/pk 5080-8732
Glass liner, disposable/deactivated 5/pk 5181-3382
6 Vespel/graphite ferrules, 1/4 in. id 10/pk 5080-8774
7 Tubing nut, 1/4 in. brass 10/pk 5180-4105
Adapters with glass liners
8 0.53 mm column adapter 19244-80540
1/8 in. column adapter 19243-80530
1/4 in. column adapter 19243-80540
9 Upper insulation‡ 19243-00067
10 Nut warmer cup with insulation 19234-60720
11 Column nut for 0.53 mm column 2/pk 5181-8830
** For a complete parts breakdown, see the 6890 Series GC Instrument User and/or Service Manuals.*‡ For Model 6890/6850 only** For a complete selection of inlet supplies, refer to Agilent’s GC Inlet Resource Guide.
SAMPLE INTRODUCTION & INLETS
Inside ofOven
1
2
3
4
5
6
8
9
10
11
1/4 in. nut
1/4 in. Vespel/
1/8 in. or 1/4 in.stainless steel liner
Liner
7
graphite ferrule
6890/6850/5890 Series GC Packed Port Supplies*
5890 Packed Column Inlet Supplies
Description Unit Part No.
Nonpurging septum nut assembly for manual flow control only, not EPC 19243-60570
Adapters without glass liners
1/8 in. column adapter 19243-80510
1/4 in. column adapter 19243-80520
Universal Packed Column Inlet (non-purged)
Septum retainer nut forheadspace sampling, nonpurging 19243-60505
Brass nut, 1/4 in. 10/pk 5180-4105
Split/Splitless Inlets
The combined “split/splitless” inlet is themost popular inlet for capillary column gaschromatography. Because it can be used ineither split or splitless mode, it provides avery effective combination that can covermost analysis requirements.
Split Mode
Split injection is an effective way tointroduce small amounts of sample withoutoverloading the column. Split injection isrequired for samples that:
� cannot be diluted for analysis (forexample, solvents)
� are gases that cannot be focused, or that have long injection times (valveinjections)
� have important minor peaks elutingdirectly before the solvent peak (as insolvent analysis)
Split injection is also good for screeningsamples of which little is known or forthose that have widely differingconcentrations, since the split ratio can be adjusted easily. Split inlets are also a good choice for dirty samples.
28 www.agilent.com/chem
Parameter Selection/Setting Rationale
Inlet temperature BP last eluting compound Ensures flash vaporizationMinimizes inlet discrimination
Inlet liner Large volume, deactivated Minimizes flashbackMinimizes degradation
Inlet packing Silanized glass wool Retains non-volatilesStops flow of droplets
Glass beads or frit Less active than woolNone Least active
Injection volume 0.5-3 µL liquid Split easily adjusted0.10-10 mL gas Split adjusted accordingly
Injection technique Fast autoinjection Less needle discriminationHot-needle fast manual Reproducible discriminationinjection
Split ratio 50:1 to 500:1 Depends on sample and injection volume
Initial column Not critical Narrow initial peakstemperatures
Septum purge 2-3 mL/min Minimizes ghosting
SAMPLE INTRODUCTION & INLETS
Split Mode Procedures/Practices
results to the lower temperature analysis.Repeat if results are positive until nofurther improvement is seen.
A majority of the problems encounteredwith split inlets are related todiscrimination and decomposition. Bothanalytical accuracy and reproducibilitydecrease with the increases indiscrimination and decomposition. Split inlets suffer from both needlediscrimination and inlet discrimination.
Troubleshooting
Split inlets are spared from most band-broadening phenomena, since narrowpeaks are generated as part of the splitting process. Therefore, any peakbroadening or tailing observed with splitinjection is usually due to improper column installation, low split flow, or low inlet temperature. If you suspect thatthe inlet temperature may be too low,increase it by 50˚C and compare the
To view a video on liner and gold seal replacement,visit www.agilent.com/chem/supplies, click on “How-to Video” under the Reference Library.
NEED MORE HELP?
Tap Agilent’s GC knowledge over the phone, on-line, in theclassroom, even at your site. See pages 56-58 for moreinformation about our experttraining, service and support.
Splitless Mode
For splitless injection, a conventional splitinjector is operated in a nonsplitting modeby closing the split valve during injection.The sample is flash-vaporized in the liner,and sample vapors are carried into thecolumn by the carrier gas where they arerecondensed at temperatures below theboiling point of the solvent. After most ofthe sample has been transferred into thecolumn, vapors remaining in the liner arecleared by opening the split vent whichremains open for the duration of the run.
The most important benefit of splitlessinjection is that a majority of the injectedsample is introduced into the column. Thisresults in much higher sensitivity than thatachieved using split injection.
Solvent Effect
One requirement of splitless injections isthat the initial column temperature shouldbe kept at least 10˚C below the boilingpoint of the sample solvent. This allows thesample solvent to condense at the front ofthe column trapping the solvent moleculesinto a tight, narrow band.
www.agilent.com/chem 29
SAMPLE INTRODUCTION & INLETS
Parameter Selection/Setting Rationale
Inlet temperature Just above highest Ensures flash vaporizationboiling point of Reduce if degradation occurssolutes (+20˚C) Use higher for dirty samples
and higher-boiling solutes
Inlet liner Large volume >0.8mL Use with autoinjectorSmall volume <0.2mL Use only for slow manual
injections
Inlet packing None Use only with slow injectionDecreases degradation
Silanized glass wool Use for fast autoinjection & dirty samples
Injection volume 0.5-2 µL liquid Depends on solvent, liner, & conditions
Injection technique Fast autoinjection Most reproducibleLess needle discrimination
Hot-needle slow manual Inject 1-2µL.sec if narrow liner is used and >1µL injection
Hot-needle fast manual Use for <1µL injections
Purge flow 20-50 mL/min Not critical
Purge delay time 20-80 sec Adjust according to column flow rate/liner type & sample conditions
Oven temperature 10-25˚C below solvent BP Necessary for solvent focusing
Column flow >2mL/min when possible Clears inlet fastReduces backflash and decomposition
Septum purge 2-3mL/min Reduces ghosting
Quantification Internal standard Maximizes reproducibilityStandard addition Use only with constant
injection volume
Retention gap 1-3m, deactivated Reduces peak distortion(1-2m per µL injected) Promotes solvent and
stationary phase focusing
Splitless Mode Procedures/Practices
Splitless injection is routinely used in areas such as:
� environmental analysis
� pesticide monitoring of foods
� drug screening
In these applications, sample preparationrequirements are significant, and it is notalways possible or economically justifiableto clean up a sample extensively. Socolumn protection becomes as importantas sensitivity. Also, samples with tracequantities of important solutes that elute
volume), leading to irreproducibility andnonlinearity of peak areas. Match inlettemperature, liner volume, and injectionvolume carefully to avoid backflash.
Decomposition
Loss of peak area or generation of newpeaks, can sometimes be dramaticallyreduced by changing liner type or bydeactivating the liner and inlet withsilanizing reagents. Removing or reducingthe amount of liner packing can alsodecrease inlet activity.
on the solvent tail may be focused by thesolvent to yield more sensitive analyses.
Troubleshooting
Most problems encountered with splitlessinjection are related to incorrect purgetime, degradation, improper focusing, andflashback.
Appropriate initial column temperature iscritical. Sample vapors can be lost throughthe septum purge line if the insert isoverfilled with sample vapor (either toolarge injection volume or too small liner
30 www.agilent.com/chem
SAMPLE INTRODUCTION & INLETS
Item Description Unit Part No.
1 Septum retainer nut 18740-60835
2 Septa**
3 Insert Weldment**
4 Liner O-ring**
5 Liner**
6 Split vent trap assembly (6890/6850 only) G1544-80550
7 Retaining nut (6890/6850 only) G1544-20590Retaining nut (5890 only) 19251-20620
8 SS seal 18740-20880Gold-plated seal 18740-20885
9 Washer, 0.375 in. od 12/pk 5061-5869
10 Reducing nut 18740-20800
11 Insulation (requires 3) 19243-00067
12 Lower insulation cover 19243-00070
13 Ferrule**
14 Column nut (6890/5890 only) 2/pk 5181-8830
Column nut (6850 only) 2/pk 5183-4732
Angled wrench for split/splitless inlet 19251-00100
**For a complete parts breakdown, see the 6890/6850/5890 Series GC Instrument User and/or Service Manuals.
**For a complete selection of inlet supplies, refer to Agilent’s GC Inlet Resource Guide.
1
2
4
56
3
7
89
10
11
12
1314
6890/6850/5890 Split/Splitless Inlet Supplies*
HELPFUL HINT: A guard column orretention gap is often beneficial forsplitless injections (see page 41).
Cool On-Column Inlets
Cool on-column injection is superior inmany ways to other sample introductiontechniques.
Advantages:� elimination of sample discrimination
� elimination of sample alteration
� solvent focusing of early eluting solutes
� high analytical precision
If done properly, cool on-column injectionprovides the most accurate and preciseresults of the available inlets. Syringediscrimination is completely eliminated.Moreover, inlet-related discrimination doesnot occur, since the liquid is introduceddirectly into the column. Automated on-column injection provides even higheranalytical precision. Add to this theelimination of thermal decomposition andrearrangement reactions, and it becomes
www.agilent.com/chem 31
Parameter Selection/Setting Rationale
Initial inlet = or 3˚C above column Ensures sample focusing temperature oven temperature in solvent front
Initial inlet Same as oven (oven track) Simple and effectivetemperature ramp Faster than oven Narrows initial peak width
Injection volume 0.1-2.0 µL liquid Use smaller injections for small id columns;Depends on column capacity
Injection technique Fast autoinjection Projects droplets away fromsyringe tip
Fused silica needle Use for manual injection into small id columns
Oven temperature Inlet temperature or Prevents backflashslightly lower
Column flow 50-80cm/sec Use for H2 carrier gas30-50cm/sec Use for He carrier gas
Septum purge 12-15mL/min Use if installed to preventghosting
Quantification All methods Inherently reproducible techniqueLack of discrimination
Retention gap 1-3m, deactivated Corrects peak distortionrequirements Protects column from non-
volatile componentsPermits autoinjection with narrow-bore columns
SAMPLE INTRODUCTION & INLETS
Cool On-Column Inlet Procedures/Practices
HELPFUL HINT: Since the sample is directly deposited into the column, nonvolatile samplecomponents can accumulate at the head of the column and will degrade efficiency and/orinteract with subsequent injections.
apparent that cool on-column injectionshould be considered whenever highprecision and accurate results are required.
Limitations:� maximum sample volumes are smaller
compared with other inlets (0.5 µL to 2.0 µL)
� solute peaks eluting just before thesolvent cannot be focused and aredifficult to determine
� capillary columns (especially those with alarge phase ratio or small inner diameter)can be easily overloaded with sample
� parameters such as initial columntemperature, solvent nature, and injectionrate must often be optimized
Sample Considerations
Sample preparation is important for on-column injection because of:
� the potential for column overload, column contamination,
� the incompatibility of some solvents with the stationary phase,
� dependence of the initial columntemperature on the boiling point of the solvent.
Many of the problems associated with these variables can be resolved by using a retention gap ahead of theanalytical column.
To view a video on cool on-column installation and septum replacement, visit www.agilent.com/chem/supplies,
click on “How-to Video” under the Reference Library.
Troubleshooting
The major problems found with cool on-column injection are associated withcolumn overload, solvent/stationary phaseincompatibility, and column contamination.
If the flooded zone after injection is toolong (large injections, poor wettability),peaks will be broad or split. A retention gapusually will resolve this problem. Loss ofcolumn efficiency with on-column injectionusually is caused by contamination ordegradation of the stationary phase at thehead of the column. Only columns with animmobilized stationary phase should beused with cool on-column injection to
prevent displacement of the stationaryphase by solvents.
Immobilized stationary phases can bewashed to remove contaminants andrenew performance. If column performancedoes not improve after washing, cut 0.5moff the inlet side of the column. If that doesnot return column performance, the columnmust be replaced and a retention gapshould be used for all further injections ofdirty samples.
32 www.agilent.com/chem
SAMPLE INTRODUCTION & INLETS
NEED MORE HELP?
Tap Agilent’s GC knowledge over the phone, on-line, in theclassroom, even at your site. See pages 56-58 for moreinformation about our experttraining, service and support.
Item Description Unit Part No.
Column nut 2/pk 5181-8830
250 µm graphite/Vespel ferrule 10/pk 5181-3323
320 µm 0.5 mm graphite/Vespel ferrule 10/pk 5062-3514
250 µm retention gap (one 5 m piece) 160-2255-5
320 µm retention gap (one 5 m piece) 160-2325-5
530 µm retention gap (one 5 m piece) 160-2535-5
Quartz deactivated column connector fits 0.18-0.53 mm 5/pk 5181-3396
Column/Retention Gap Installation Consumables
HELPFUL HINT: Sample degradation canoccur with cool on-column injection ifcolumn or retention gap activity is high.Use only well-deactivated retention gapsand high quality capillary columns fromAgilent.
Only a small sampling of inlet supplies are shown here. For a complete selection of inlet supplies, see the Agilent 2002-2003 Chromatography & Spectroscopy Supplies Reference Guide. www.agilent.com/chem 33
SAMPLE INTRODUCTION & INLETS
Item Description Unit Part No.
Manual injection
1c Cooling tower assembly 19320-80625
1d Duckbill septum 10/pk 19245-40050
Fused silica syringe needles 6/pk 19091-63000
Syringe barrel for use with fused-silica needles,10 µL 9301-0658
Common Supplies
3 Spring 19245-60760
4 Inserts for capillary columns
For 200 µm columns (one ring) 19245-20510
For 250 µm columns (six rings) 19245-20515
For 320 µm columns (five rings) 19245-20525
For 530 µm columns (no rings) 19245-20580
For 530 µm Al clad columns (four rings) 19245-20780
5 Ferrule 5080-8853
6 Column nut 2/pk 5181-8830
6890 Series GC Cool On-Column Inlet Supplies
Automatic Injection
1a Septum nut base for 320 mm assembly 19245-80521
1b Septum nut base for 530 mm assembly G1545-80520
2 Advanced green 5 mm through hole septa 50/pk 5183-4760BTO 5 mm through hole septa 50/pk 5183-4758
5890 Series Cool On-Column Inlet Supplies
Automatic Injection
1a Septum nut (5890 Series II GC) 19245-80520
1b Needle guide (for 7673A only) 19245-20670
*For a complete parts breakdown, see the 6890/5890 Series GC Instrument User and/or Service Manuals.
6890/5890 Series Cool On-Column Inlet Supplies
1b
2
5
6
1c1a
34
1d
To view a video on PTV column installation, liner installation and silver seal replacement,
visit www.agilent.com/chem/supplies, click on “How-to Video” under the Reference Library.
PTV inlets combine the benefits of split,splitless and on-column inlets. The sample isusually injected into a cool liner, so syringeneedle discrimination does not occur. Thenthe inlet temperature is increased to vaporizethe sample. The user programs vent timesand temperature to achieve the equivalent ofsplit or splitless transfer of sample vapors tothe column. PTV injection is considered themost universal sample introduction systembecause of its flexibility.
Advantages� no syringe-needle discrimination� minimal inlet discrimination� no special syringe needed� use of large injection volumes� removal of solvent and low boiling
components� trapping of nonvolatile components in liner� split or splitless operation� retention time and area reproducibility
approaching cool on-column injection
PTV inlets are actively cooled before andduring injection by Peltier devices or byforced gases (air, liquid N2, or liquid CO2).Cryogenic cooling of the inlet can reduceinlet temperature enough to thermallyfocus gas injections from other samplingdevices in the liner. This is a distinctadvantage of using PTV inlets incomparison to conventional inlets forcoupling auxiliary sampling devices tocapillary columns.
Post-injection, PTV inlets are heated using electrical heaters or preheatedcompressed air. Depending on design, inlet temperature ramps are either ballistic (i.e., ramped to the maximumtemperature at an uncontrolled maximumrate) or programmable.
34 www.agilent.com/chem
Parameter Selection/Setting Rationale
Injection mode Cold split For general use and sample screening
Cold splitless For trace analysis
Inlet temperature Adjustable (i.e., 2˚C/sec Use slower ramp rates for ramp rate to 12˚C/sec) labile, complex, or large
volume samples Use faster ramp rates for most samples Use faster ramps rates to shorten splitless purge delay time
Ballistic Simpler, less expensive instrumentation
Inlet liner Straight with silanized wool For general useBaffled For labile samplesPacked with an adsorbent For focusing gaseous
injections from auxiliary sampling devices
Injection volume 0.1-1.5µL Use lower volumes for volatile solvents and fast ramp ratesUse volumes larger than 1.5µL only in solvent- elimination mode
Sample Injection Autosampler or manual, Not critical for cold split technique fast or slow & splitless modes
Oven temperature 10-25˚C below solvent BP For proper solvent effect insplitless mode
Sample dependent For split mode
Column flow 30-50 cm/sec Clears inlet fasterLess backflash
Septum purge 1-5mL/min Minimizes ghosting
Quantification Any method Inherently reproducibleLow discrimination in coldinjection modes
Retention gap 1-3m, deactivated Compensates for extended flooded zone and solvent-column incompatibility
SAMPLE INTRODUCTION & INLETS
Programmed Temperature Vaporizer (PTV) Inlets
PTV Inlet Procedures/Practices (cold split/splitless modes)
HELPFUL HINT: There are few choices in liner design for PTV inlets.However, liner volume and activity are stillkey issues to be considered when selectingamong the few available PTV liners. PTVliners require packing or a modified surface to hold the liquid sample in placebefore and during the vaporizing process.
www.agilent.com/chem 35
Item Description Column ID Unit Part No.
1 Septumless head G2617-60507
2 Septum head G2618-80500
3 Septum nut 18740-60835
4 PTV inlet assy G2617-60506
5 PTV LCO2 cooling jacket G2617-60508
6 PTV LN2 cooling jacket G2619-60501
7 Silver seal 5/pk 5182-9763
8 Graphpak inlet adapter 0.20 mm 5182-9754
0.25-0.33 mm 5182-9761
0.53 mm 5182-9762
9 Ferrules for 0.20 mm 10/pk 5182-9756
Graphpak inlet 0.25 mm 10/pk 5182-9768
0.32 mm 10/pk 5182-9769
0.53 mm 10/pk 5182-9770
10 Split nut for inlet adapters 5062-3525
11 PTV insulation block G2617-20510
PTV cryo insulator (not shown) G2617-60510
Teflon ferrule (needle seal) 5182-9748
Kalrez seal 5182-9759
Valve body 5182-9757
Pressure spring 5182-9758
Viton seal 5182-9775
Sealing element 5182-9760
CO2 Cryo inline filter 3150-0602
Service kit for septumless head 5182-9747contains Kalrez seal, valve body, and pressure springGraphpak 3D ferrules 5/pk 5182-9749
Installation tool for 3D ferrules G2617-80540
SAMPLE INTRODUCTION & INLETS
1
2
3
4
5, 6
78910
11
6890 PTV Inlet
PTV Liners
Description Part No.
PTV Liner Single Baffle, 2 mm id 180 µL volume, deactivated, glasswool 5183-2038
PTV Liner Single Baffle, 2 mm id 200 µL volume, deactivated 5183-2036
PTV Liner Multi Baffle, 1.5 mm id 150 µL volume, deactivated 5183-2037
PTV Liner Fritted Glass, 1.5 mm id 150 µL volume, deactivated 5183-2041
Liners
Liners are the centerpiece of the inletsystem in which the sample is vaporizedand brought into the gas phase.
The liner should be changed on a regularbasis, and the correct liner must be used to avoid peak shape degradation, solutediscrimination, poor reproducibility, sampledecomposition, and ghost peaks. Changeliners on a regular basis, as determined by:
� previous use pattern
� sample cleanliness
� chromatographic abnormalities such aspeak shape changes, peak discrimination,poor reproducibility, sample pyrolysis
Ferrules
Ferrules seal the connection of the columnor liner to the system. The ideal ferruleprovides a leak-free seal, accommodatesvarious column outer diameters, seals withminimum torque, will not stick to thecolumn or fittings, and will toleratetemperature cycling.
Signals that a ferrule is damaged include:
� background noise from oxygen diffusinginto the system
� column bleed catalyzed by oxygen
� sample degradation
� loss of sample
� increase in detector signal/noise
� poor retention time reproducibility
Septa
The septum isolates the sample flow pathfrom the outside world. It must provide abarrier that is readily penetrated by theinjector needle while maintaining internalpressure without contaminating theanalysis. Septa are generally made ofspecial high temperature, low-bleedsilicone rubber formulations. Septa shouldbe replaced regularly to avoid leaks,decomposition, sample loss, reducedcolumn or split vent flow, ghost peaks, and column degradation.
To minimize problems:
� use septa with the recommendedtemperature range
� change septa regularly� install the retainer nut “hand tight”� use septum purge when available� use autoinjectors� use Agilent dual-taper, conical point
syringe needles
36 www.agilent.com/chem
SAMPLE INTRODUCTION & INLETS
For a complete selection of inletsupplies, refer to Agilent’s
GC Inlet Resource Guide.(publication # 5988-3466)
Installation
Be sure to install ferrules correctly to avoidproblems:
� don’t overtighten – finger-tighten columnnut, then use wrench to tighten 1/4 turn
� maintain cleanliness
� bake out ferrules prior to use
� avoid contamination (i.e., fingerprints,oils)
� inspect used ferrules with magnifier forcracks, chips, or other damage beforereusing them
� change ferrules when new columns orinjector/detector parts are installed
Columns
Choosing the right GC column andfollowing Agilent’s simple column carerecommendations will maximize GCcolumn performance and lifetime. In thissection our experts offer practical adviceon how to select, install and store your GC column, plus give helpful hints aboutavoiding thermal and oxygen degradation.Because GC column contamination is the primary cause of shortened columnlifetime, we’ve also included a detaileddiscussion about the prevention of non-volatile and semi-volatile contamination, as well as appropriate recovery measures.
“With our expertise in GC columns andapplications we can quickly assist youwith choosing the right column for yourapplication, and save you time and moneyby helping you protect your GC columnfrom permanent damage and commonsources of contamination.”
Eberhardt Kuhn, Ph.D.Technical Support Engineer
www.agilent.com/chem 37
NEED MORE HELP?
Tap Agilent’s GC knowledge over the phone, on-line, in theclassroom, even at your site. See pages 56-58 for moreinformation about our experttraining, service and support.
38 www.agilent.com/chem
COLUMNS
While GC column maintenance is simple, the frequency and type of column maintenance that is required varies due to many system and samplefactors. Instead of simply following a
Description Part No.
DB-1ms, 0.25mm i.d., 30m, 0.25µm 122-0132
HP-5ms, 0.25mm i.d., 30m, 0.25µm 19091S-433
DB-XLB, 0.25mm i.d., 30m, 0.25µm 122-1232
DB-35ms, 0.25mm i.d., 30m, 0.25µm 122-3832
HP-INNOWax, 0.25mm i.d., 30m, 0.25µm 19091N-133
Column Installation & Setup
Column Selection
Choose the Column that offers the bestlongevity:
� Use low-bleed columns wheneverpossible.
� Choose the least polar column thatprovides the best resolution for the mostdifficult separation.
� Use more polar phases when difficultisomer separations are required. (Choosea more polar phase when you must, buttry to make it the least polar column thatwill do the job.)
� Use most favorable dimensions to enablerequired separation while optimizingtemperature ranges.
The first step in obtaining optimal column performance and lifetime is proper installation:
� Choose the appropriate size and material ferrule for the column, injector and detector type.
� Avoid re-using ferrules.
� Use an appropriate column cutting tool such as a ceramic wafer or diamond tipped scribe.
Column Maintenance
predefined timetable of maintenance items,the main focus should be how to obtain the highest performance and lifetime from a capillary column. This depends onchoosing the right column, correct
installation/system setup, and avoiding the primary factors that cause columnperformance degradation (breakage,thermal damage, oxygen damage, chemicaldamage and contamination).
� Make sure column ends are cleanly cut and free of particulate matter before installing into the injector and detector.
� Install the column the appropriatedistance into the injector and detector as specified by the GC manufacturer.
� The column should be placed on a column hanger and no portion of the capillary tubing should touch the oven walls.
� Verify that all fittings are leak-free and the carrier gas is oxygen-free beforeheating the oven.
Bad
Good
Example of column cuts
www.agilent.com/chem 39
COLUMNS
� Check the installation and set the linear velocity by injecting a non-retainedcompound.
� Condition the column as specified in theliterature provided with each column.
Description Part No.
Ceramic wafer (4/pk) 5181-8836
20x Magnifier 430-1020
General Purpose Graphite ferrule (0.5mm ID, for column IDs ≤ 0.32mm) 10/pk 5080-8853
General Purpose Graphite ferrule (1.0mm ID, for 0.45-0.53mm ID columns) 10/pk 5080-8773
Gas leak detector 115V 5182-9646 Gas leak detector 220V (US only) 5182-9648
Column Breakage
Fused silica columns can break whereverthere are small scratches or abrasions inthe protective polyimide coating.Continuous heating and cooling of theoven, vibrations caused by the oven fan as well as being wound on a circularcage all place stress on the tubing. While under these stresses, flaws will propagate until breakage occurs.
NOTE: Larger diameter columns (0.45- 0.53mm id) are more prone to breakage.
Description Part No.
Fused Silica Union, Universal 2-way (5/pk) 705-0905
Quartz deactivated column connector (5/pk) 5181-3396
Polyimide Sealing resin (5 grams) 500-1200
Causes of Performance Degradation
This is a small sampling of the many GC columns and parts. For a complete selection, see the Agilent 2002-2003 Chromatography & Spectroscopy Supplies Reference Guide.
Column Installation & Setup continued
Prevention� Avoid scratches and abrasions by not
exposing the column to sharp edges suchas column hangers and tags, metal edgesin the GC oven, column cutters and othermiscellaneous items on the lab bench.
� Avoid winding or bending the column too tightly.
Recovery � If a broken column has been heated,
damage to the stationary phase is verylikely. Discard the back of the column (the column half without carrier gas). Trim 6 inches off of the end of the column and reinstall.
� If the broken column has not beenheated, connect the two pieces with a low volume union. No more than 2-3 unions should be installed for one column.
40 www.agilent.com/chem
Description Part No.
FlowTracker 2000 Flowmeter and Leak Detector 5183-4780
Big Oxygen Trap (750 cc, 1/8” fitting) BOT-2
Big Moisture Trap (750 cc, 1/8” fitting) BMT-2
Big Universal Trap (Combination Trap) (750cc, 1/8” fitting, He) RMSH-2
Advanced Green Septa (11mm, 50/pk) 5183-4759
COLUMNS
HELPFUL HINT: Install a moisture trapupstream of the oxygen trap to increase the oxygen trap lifetime.
Thermal Damage
Exceeding a column’s upper temperaturelimit results in accelerated degradation ofthe stationary phase and tubing surface.This results in the premature onset ofexcessive column bleed, peak tailing foractive compounds and/or loss of efficiency(resolution).
Prevention � Do not exceed the columns specified
upper temperature limits:
– Isothermal limit: temperature that the column can be held at for anindefinite time
– Programmed limit: maximum columntemperature; column should only beheld there for about 5-10 minutes
� Set the GC maximum oven temperaturefunction at or a few degrees above thetemperature limit of the column. With twocolumns in the oven be sure to set themaximum temperature to the temperaturelimit of the column with the lowest value.
Recovery � Disconnect column from detector
� Heat the column 8-16 hours at theisothermal limit
� Remove 10-15 cm from the column end
� Reinstall into the detector and conditionas usual
NOTE: Thermal damage cannot be reversed.The column usually does not return to itsoriginal performance; however, it is oftenstill functional. The life of the column willbe reduced after thermal damage.
Oxygen Damage
Oxygen is an enemy to all capillary GCcolumns. Constant exposure to oxygendoes not damage the column at or nearambient temperatures; however, severedamage occurs as the column temperatureincreases. A leak in the carrier gas flowpath (e.g., gas lines, fittings, injector, septa)is the most common source of oxygenexposure. As the column is heated, veryrapid degradation of the stationary phaseoccurs. This results in the premature onsetof excessive column bleed, peak tailing foractive compounds and/or loss of efficiency(resolution).
NOTE: Momentary exposure to oxygen such as an injection of air or removing the septum nut for a short period of time is not a problem.
Prevention� Maintain an oxygen and leak free
system by:
– performing periodic leak checks
– changing septa regularly
– using high quality carrier gases
– installing and maintaining oxygen traps
– changing gas cylinders before they arecompletely empty
Recovery
Perform column “bakeout” as describedunder thermal damage recovery.
NOTE: Oxygen damage occurs very rapidly.In less severe cases, the column may stillbe functional but at a reduced performancelevel. In more severe cases, the column isirreversibly damaged.
GUARD COLUMN
A guard column is a piece of fused silica tubing attached with a union tothe front of the analytical column with the following characteristics:
� Material should be deactivated fused silica tubing to minimize soluteinteractions.
� Length should be from 1-10 meters. Typical lengths of 5-10 meters allowsubstantial trimming before the entire guard column has to replaced.
� Internal diameter should be the same as the column. Guard columns with larger ids can be used.
� A low volume union should be used to attach the tubing to the column.Glass pressfit unions are inexpensive and easy to install. DuraGuardcolumns offer the guard column built into the analytical column as asingle piece of fused silica, eliminating the need for unions.
Guard columns are used to minimize the effect of non-volatile residues on the analysis. The non-volatile residues deposit in the guard column andnot in the analytical column. This greatly reduces the interaction betweenthe residues and the sample. Periodic cutting or trimming of the guardcolumn is usually required upon a build-up of residues. The onset of peakshape problems is the usual indicator that the guard column needstrimming or changing.
INJECTOR DETECTOR
Guard Column
Union
Column
Guard column installation instructions are available at www.agilent.com/chem. Click
on “Consumer Products.”
Guard Column
Chemical Damage
Inorganic or mineral acids and bases arethe primary sources of chemical damage to stationary phases. Most of these acidsand bases have low volatility andaccumulate at the front of the column. Ifallowed to remain, the acids or basesdamage the stationary phase. The onlyorganic compounds that have beenreported to chemically damage stationaryphases are perfluoroacids and these needto be present at high levels (e.g., 1% orhigher). This results in the premature onsetof excessive column bleed, peak tailing foractive compounds and/or loss of efficiency(resolution).
NOTE: Hydrochloric acid and ammoniumhydroxide are the least harmful of the groupas both tend to follow any water that ispresent in the sample. Thus, if HCl or NH4OHare present in a sample, minimizing waterretention will render these compoundsrelatively harmless to the column.
Prevention� Perform sample preparation to remove
inorganic acids and bases from thesample
� Install guard column and trim frequently� If acids or bases must be used choose an
organic alternative or HCl or NH4OH
Recovery� Remove 0.5 to 1 meter from the front
of the column� Severe cases may require the removal
of 5 or more meters
Column Contamination
Column contamination is the most commonproblem encountered in capillary GC.Unfortunately, it mimics most otherchromatographic problems and is oftenmisdiagnosed. A contaminated column isusually not damaged, but it may berendered unusable. There are two basictypes of contaminants: nonvolatile andsemivolatile.
COLUMNS
www.agilent.com/chem 41This is a small sampling of the many GC columns and parts. For a complete selection,
see the Agilent 2002-2003 Chromatography & Spectroscopy Supplies Reference Guide.
Nonvolatile Contaminants Nonvolatile contaminants or residues donot elute and accumulate in the column(most often confined to the first fewmeters). The column becomes coated withthese residues which interfere with theproper partitioning of solutes in and out of the stationary phase. Also, the residuesmay interact with active solutes resulting in peak adsorption problems (evident aspeak tailing or loss of peak size). Activesolutes are those containing a hydroxyl (-OH) or amine (-NH) group, and somethiols (-SH) and aldehydes.
Prevention � Perform sample cleanup to remove
nonvolatile materials from the sample
� Use injection port liners packed withglass wool (may not be feasible whenanalyzing active compounds)
� Install a guard column and trim regularly
Recovery � Do not bakeout the column
� Front End Maintenance:
– Clean or change the injection port liner
– Clean out the injector
– Cut off typically 0.5 to 1 meter of thefront of the column
� Turn the column around (install detectorend into injector)
� Solvent rinse the column
� Cut the column in half and use the backhalf (detector side).
Semivolatile ContaminantsSemivolatile contaminants or residuesaccumulate in the column, but eventuallyelute. Hours to days may elapse before theycompletely leave the column. Likenonvolatile residues, they may cause peakshape and size problems and, in addition,
are usually responsible for many baselineproblems (instability, wander, drift, ghostpeaks, etc.).
Prevention� Perform sample cleanup to remove
semi-volatile materials from the sample
� Increase the final temperature of the GC run (not to exceed the temperaturelimit of the column)
� Change septa regularly
Recovery � Bakeout the column: limit 1-2 hours
(excess baking may polymerize somecontamination and reduce columnlifetime)
� Solvent rinse the column
42 www.agilent.com/chem
COLUMNS
Description Part No.
SPE product guide Pub#5988-2685EN
Split/Splitless Inlet liner: glass wool,taper, deactivated (5/pk) 5183-4712
Splitless Inlet liner: single-taper, no glass wool, deactivated (5/pk) 5183-4695
Quartz deactivated column connector (5/pk) 5181-3396
Polyimide sealing resin (5 grams) 500-1200
Deactivated Fused silica, 10m, 0.53mm i.d. 160-2535-10
Deactivated Fused silica, 10m, 0.25mm i.d. 160-2255-10
Capillary column rinse kit 430-3000
Column Storage
Capillary columns should be stored in theiroriginal box when removed from the GC.Place GC septa over the ends to preventdebris from entering the tubing. Uponreinstallation of the column, the columnends need to be trimmed by 2-4 cm toensure that a small piece of septa is notlodged in the column.
If a column is left in a heated GC, thereshould always be carrier gas flow throughthe column. The carrier gas flow can beturned off only if the oven, injector, detectorand transfer lines are turned off (i.e., notheated). Without carrier gas flow, damageto the heated portion of the column occurs.
Only a small sampling of FID supplies are shown here. For a complete selection of FID supplies, see the Agilent 2002-2003 Chromatography & Spectroscopy Supplies Reference Guide.
“GC detectors are highly sensitivesystems that are often compromised
by various types of contamination. Byimplementing some recommended
detector maintenance routines, youcan minimize instrument downtime
and keep your GC system working atpeak efficiency.”
Bernhard RothweilerApplications Chemist
Detectors
Most detectors require simple but periodiccleaning to maintain peak performance.This is especially true for highly sensitiveGC detectors. Without routine detectormaintenance, GC system performance willdeteriorate and can cause detector failure.Detailed procedures on how to clean,maintain and replace common detectors,including FID, TCD, NPD, ECD, and FPD aresummarized in this section. Also includedare special handling techniques andspecific recommendations to maximizespecific detector operations. For example,learn how to resolve flame ignitionproblems associated with your flamephotometric detector and test electroncapture detectors for radioactivity leaks.
www.agilent.com/chem 43
Description Unit Part No.
6890/6850/5890 Common TCD Supplies
TCD replacement cell (6890/6850 only) G1532-60675
TCD cap column adapter seal 10/pk 18740-20950
TCD cap column adapter 18740-20960
Graphite ferrules, 1.0 mm id 10/pk 5080-8773
Graphite ferrules, 0.5 mm id 10/pk 5080-8853
Capillary column nut, for 6890 2/pk 5181-8830
Capillary column nut, for 6850 2/pk 5183-4732
TCD packed column adapter (6890/6850 only) G1532-20710
TCD chemical sample kit, 3 ampoules, 0.5 mL, 5 solution of 0.3% C14, C15, and C16, normalalkanes in hexane 18711-60060
5890 TCD Supplies
Makeup gas adapter, TCD 19232-80550
TCD column adapter, 1/8 to 1/4 in. glass 19302-80020
TCD replacement cartridge 19232-60676
The TCD compares the thermalconductivities of two gas flows — purecarrier gas (also called the reference gas)and carrier gas plus sample components(also called column effluent).
Filament Maintenance
The primary maintenance for a TCDinvolves the filament. Most proceduresinvolve improving filament life or keep thefilament from becoming damaged orcontaminated.
A constant presence of oxygen canpermanently damage filaments throughoxidative processes. The most commonsource of oxygen is elevated levels in thecarrier or makeup gas or a leak near thedetector. Oxygen traps are recommendedfor the carrier and makeup gases to reduceoxygen levels. Proper column installationtechniques and regular leak checks(especially after column installation) helpto keep leak problems to a minimum.
The damage caused by oxygen is moresevere at high filament currents.Chemically active sample components such as acids and halogenated compoundsmay attack and damage the filaments.Avoiding these compounds when possibleincreases filament life. Turning off orsubstantially reducing the filament currentwhen the TCD is not in use also prolongsfilament life.
Increasing Filament Lifetime
Increased filament lifetime will result if thefollowing startup process is used:
1. Purge the detector with carrier andmakeup gas for 10-15 minutes beforeturning on the filaments. This preventsoxidation of the filaments due to thepresence of oxygen that has diffused intothe cell under no flow conditions.
2. Turn on the filaments at the lowestpossible current setting, then increasethe filament current in severalincrements to the desired value. Thisreduces the power surge upon current
introduction and prolongs filamentlifetime.
Cell Contamination
Cell contamination is a problem when alower detector temperature is used toimprove sensitivity. Also, low filamentcurrents promote contamination since the filament is maintained at a lowertemperature at lower currents. If the cellbecomes contaminated, a solvent flush of the detector may help to remove thecondensed material.
44 www.agilent.com/chem
DETECTORS
Thermal Conductivity Detector (TCD)
Thermal Conductivity Detector (TCD) Supplies
Solvent Flush Procedure
1. Cool the cell to room temperature andremove the column.
2. Place a septum in a nut or fittingassembly that fits onto the detectorentrance.
3. Place the nut or assembly on thedetector fitting and tighten. Verify the presence of makeup gas flow.
4. Inject 20-100 µL volumes of toluene orbenzene into the detector through theseptum. Inject a total volume of at least 1mL of solvent. Do not injecthalogenated solvents such as methylenechloride and chloroform into the detector.
5. After the final injection, allow makeupgas to flow for 10 minutes or more.Slowly raise the temperature of the cellto 20-30˚C above the normal operatingtemperature.
6. After 30 minutes, decrease thetemperature to the normal value andinstall the column as usual.
Thermal Cleaning
The TCD can become contaminated withdeposits from such things as column bleedor dirty samples. A wandering baseline,increased noise level, or changes inresponse on a checkout chromatogram allindicate contamination. Thermal cleaning,or bakeout (heating the detector block toevaporate the contaminant), should beperformed only after you have confirmed
that the carrier gas and the flow systemcomponents are leak-free and contaminant-free.
Watch out for decreased sensitivity causedby samples that react with the filament,originating from oxygen-contaminatedcarrier gas, leaks in plumbing, or columnbleeding. Samples with active components,such as acids and halogenated compoundscan chemically attack the filament as well. Also, sample condensation willcontaminate the detector cell if thetemperature is too low.
Some types of contaminants can beremoved by temperature bakeout. Also, in non-modulated designs, wanderingbaselines due to temperature variation canbe corrected by making sure the detectortemperature remains constant.
www.agilent.com/chem 45
DETECTORS
Bead Maintenance
NPDs are temperamental and requirefrequent maintenance. Small changes in any of a number of parameters cansignificantly change the performancecharacteristics of an NPD. The beadrequires the most maintenance. It needs to be changed frequently, thus a spare is a necessity.
The beads have to be kept dry which limitstheir storage life to about six months.When a new bead is installed, slowly raisethe detector temperature and bead current.Rapid heating can crack or break the beadespecially if it has been stored under humidconditions. It has been observed that
higher hydrogen flows and bead currentsdecrease bead life. If the NPD is not in use,the hydrogen flow and bead current shouldbe reduced or turned off to increase beadlife. Make sure there is some type of gasflow in a heated detector or when there iscurrent to the bead.
Bead Life
To extend the life of the bead:
� Use the lowest practical adjust offset orbead voltage.
� Run clean samples and keep theinlet/liner clean to minimizecontamination.
� Turn off the bead when not in use.
� Keep the detector temperature high (320 – 335˚C).
� Turn off the hydrogen flow during solventpeaks and between runs.
� If the NPD is off for an extended period of time in a high humidity environment,water may accumulate in the detector. To evaporate this water, set the detectortemperature to 100˚C and maintain it for 30 minutes. Then set the detectortemperature to 150˚C and maintain it for another 30 minutes.
Nitrogen-Phosphorus Detector (NPD)
Gas Flow
The hydrogen, air and makeup gas flowsshould be measured frequently. They candrift over time or be changed unintentionallywithout knowledge of it occurring. Each gasflow should be measured independently toobtain the most accurate values. NPDs arevery sensitive to changes in the gas flowsand consistent flows are necessary tomaintain performance levels.
Gas Purity
Because of its high sensitivity, the NPDrequires very pure gases (99.999% orbetter). We strongly recommend thatmoisture and hydrocarbon traps be used on the carrier gas and all detector gases,including the detector hydrogen, air, andmakeup gases. Dirty gases will not onlygive poor chromatographic performance,but will shorten the bead life as well.
Cleaning & Replacement
The NPD requires periodic cleaning. Inmost cases, this only involves the collectorand the jet. Agilent provides brushes andwires that simplify the cleaning of alldetector parts (see FID Supplies on page53). The brushes are used to dislodgeparticulates clinging to the metal surfaces.A fine wire is used to clean the jet openingof particulates. Do not force too large awire or probe into the jet opening or theopening will become distorted. A loss ofsensitivity or poor peak shape may result ifthe opening is deformed. The various partscan be ultrasonicated after cleaning with a brush. Eventually the jet needs to bereplaced, so it is strongly recommended to have spare jets on hand.
Over time, residue from the bead or samplecan build up in the collector and causebaseline problems. You should clean thecollector after you have changed the beadtwo or three times.
The metal C-rings wear slightly with eachassembly and disassembly. After severalassemblies and disassemblies (five ormore), the rings may not seal effectively,causing an erratic baseline. A ceramicinsulator and seal kit is available. Alwayscool the detector to near-ambient whenchanging seals and insulators.
Because there is no flame in the NPD, thejet does not collect silica and soot as does
the FID jet. Although you can clean the jet,it is usually more practical to simply replacedirty jets with new ones. If you do clean thejet, use the cleaning wire, taking care notto damage the inside of the jet. You canalso use a sonicator bath to clean the jet.
Contaminants
Some chemical problems can also arisewhen using the NPD. Because it is a tracedetector, be careful not to contaminate theanalytical system.
Glassware
Glassware must be very clean. Phosphatedetergents should be avoided, so acidwashing of glassware followed by distilledwater and solvent rinsing is recommended.
Solvents
Solvents should be checked for purity.Chlorinated solvents and silanizingreagents can decrease the useful lifetimeof the alkali source; excess reagent shouldbe removed prior to injection, if possible.
Other Contamination Sources
Phosphate-containing leak detectors,phosphoric acid-treated columns or glasswool, polyimide-coated columns, ornitrogen-containing liquid phases can addnoise to the system and should be avoided.
46 www.agilent.com/chem
DETECTORS
Description Length (mm) Part No.
Capillary jet (0.011 in./0.29 mm id tip)(6890 only, dedicated) 48 G1531-80560
6890/5890 Adaptable
Capillary 0.53 mm jet (0.011 in. id tip) 61.5 19244-80560
Packed (0.018 in. id tip) 63.5 18710-20119
NPD Jets
For a complete selection of NPD supplies, see the Agilent 2002-2003 Chromatography & Spectroscopy Supplies Reference Guide. www.agilent.com/chem 47
DETECTORS
14
18
17
1
3
45
6
8
13
15
7
2
9
1011
12
16
Item Description Part No.
6890 NPD Supplies
1 Screws, M3 x 0.5 x 8 mm (Pozidriv) 0515-0655
2 NPD white ceramic bead assembly* G1534-60570
NPD black ceramic bead assembly** 5183-2007
3 Lid weldment G1534-80510
4 Metal C-ring, top 0905-2580
5 Alumina insulator, upper G1534-40020
6 Collector funnel G1534-20530
7 Alumina insulator, lower G1534-40030
8 Metal C-ring bottom and top 0905-1284
9 Screw, M4 x 10 mm 0515-2495
10 J-Clamp 1400-0015
11 Screw, M4 x 10 mm 0515-2495
12 NPD interconnect assembly G1534-60610
13 Mounting pallet G1531-40020
14 Jets (see page 54)
15 Base weldment, Capillary NPD G1534-80500
Base Weldment, Packed NPD G1534-80540
16 Lid stop G1534-20590
NPD Ceramic Insulator Kit includes items 4, 5, 7, and 8 5182-9722
17 Column adapters for packed NPD
18 Nut warmer cup with insulation 19234-60720
5890 NPD Supplies
NPD collector (NPD bead) 19234-60540
Recoating kit, sufficient for 10 collectors 5080-8872
Detector Trap Replacement Kit 19231-60790
*This bead is more sensitive but exhibits some tailing for phosphorous compounds. Quantity discounts available.
**The black bead is potentially a little less sensitive but does not exhibit peak tailing and typically has longer lifetime.
Nitrogen-Phosphorous Detector (NPD) Supplies
Agilent provides two types of electroncapture detectors. The regular detector(ECD) has a larger internal volume(approximately 10 times) than the micro-cell detector (µ-ECD). These two types canbe distinguished by the top cover of thedetector — the ECD has a solid cover andthe µ-ECD has a perforated cover.
Thermal Cleaning
If your baseline is noisy or the output value is abnormally high and you havedetermined that these problems are notbeing caused by leaks in the GC system,you may have contamination in thedetector from column bleed. To removecontamination, you should perform athermal cleaning (bakeout) of the detector.
Warning: Detector disassembly and/orcleaning procedures other than thermalshould be performed only by personneltrained and licensed appropriately tohandle radioactive materials. Traceamounts of radioactive 63Ni may beremoved during other procedures, causing possible hazardous exposure to ß and x-radiation.
Radioactivity Leak Test
Electron capture detectors must be testedfor radioactive leakage at least every sixmonths. Records of tests and results mustbe maintained for possible inspection bythe Nuclear Regulatory Commission and/orthe responsible local agency. More frequenttests may be conducted when necessary.
The procedure used is a “wipe test.” Awipe test kit is supplied with each newdetector. Refer to the information cardsupplied in the Wipe Test Kit forinstructions on performing the test.
Gas Purity
For successful EC detection, it’s importantthat the carrier and purge gases are veryclean and dry (99.9995%). Moisture, oxygen,or other contaminants can be responsiblefor improved sensitivity, but at a cost oflinear range. Always precondition thecolumn before connection to the detector.
48 www.agilent.com/chem
DETECTORS
Electron-Capture Detector (ECD)
ECD Warnings
Although beta particles at this energy level have little penetrating power — the
surface layer of the skin or a few sheets of paper will stop most of them — they
may be hazardous if the isotope is ingested or inhaled. For this reason the cell
must be handled with care. Radioactive leak tests must be performed at the
required intervals, the inlet and outlet fittings must be capped when the detector
is not in use, corrosive chemicals must not be introduced into the detector, and
the effluent from the detector must be vented outside the laboratory environment.
NEED MORE HELP?
Tap Agilent’s GC knowledge over the phone, on-line, in theclassroom, even at your site. See pages 56-58 for moreinformation about our experttraining, service and support.
www.agilent.com/chem 49
Item Description Unit Part No.
6890 ECD Supplies
ECD makeup gas adapter* G1533-80565
Nut warmer cup with insulation 19234-60720
5890 ECD Supplies
1 Vespel graphite ferrule, 1/4 in. id 10/pk 5080-8774
Vespel/graphite 85%/15% ferrule, 1/4 in. id 10/pk 0100-1331
2 Tubing nut, 1/4 in. brass 10/pk 5180-4105
3 ECD column adapter, 1/4 to 1/8 in. metal 19301-80530
4 Makeup gas adapter for micro ECD adapter G2397-80520
5 Makeup gas adapter, ECD, new style 19233-80565
6890/5890 Common ECD Supplies
6 ECD fused silica liner (new style) 19233-20625
ECD adapter fused silica liner micro ECD G2397-20540
7 Stainless steel cap for ECD makeup gas adapter 19233-20755(new style and micro ECD)
ECD Performance evaluation sample lindane and aldrin (0.033 ppm) in Isooctane 3 ampoules, 0.5 mL 18713-60040
ECD wipe test kit 18713-60050
*Includes one each of P/N 19233-20625 and P/N 19233-20755.
DETECTORS
3
2
1
ECD Packed for 1/4 in. Glass Columns
5, 4
6
7
ECD Make up Gas Adapter
Electron-Capture Detector (ECD) Supplies
Maintenance
Flame Photometric Detectors requireminimal maintenance to keep themperforming at satisfactory levels. Thehydrogen, air and makeup gas flows shouldbe measured occasionally. They can driftover time or be changed unintentionallywithout knowledge of it occurring. Each gasflow should be measured independently toobtain the most accurate values.
Cleaning & Parts Replacement
The FPD requires periodic cleaning. In most cases, this only involves the jet, andless frequently, the filter. Agilent providesbrushes and wires that simplify thecleaning of all detector parts (see FIDSupplies on page 53). The brushes are usedto dislodge particulates clinging to themetal surfaces. A fine wire is used to cleanthe jet opening of particulates. Do not forcetoo large a wire or probe into the jetopening or the opening may becomedistorted. A loss of sensitivity, poor peakshape, and/or lighting difficulties mayresult if the opening is deformed. The filteror any of the window parts should behandled gently. Scratches or other surfacedeformities reduce the amount of lightpassing through the filter, thus reducingresponse. The filter and related partsshould be clean and free from fingerprints.
The Photo Multiplier Tube needs periodicreplacement. The PMT is defective andneeds to be rebuilt or replaced if:
� high voltage is on and the flame is lit
� low or no signal and/or noise notattributed to any other source such asbad cables are observed
� light leaks occur
� high temperatures are used
� defective signal boards are present
High detector temperatures reduce thePMT life. When not in use, turn off the PMTto maximize its usable lifetime. Some PMTsmay have a shelf life and should not bestored for prolonged periods before use.
Column bleed and/or effluent cancontaminate the first quartz window (heatshield) nearest the detector module. Dust,fingerprints, and atmospheric contaminantscan dirty both quartz windows, the filter,and/or the photomultiplier tube window.Contamination anywhere along the lightpath between flame and PMT can reducedetector sensitivity.
If a response problem is encountered(sensitivity, noise, selectivity) the FPD jetshould be inspected for deposits and, ifnecessary, cleaned or replaced. To properlyservice the jet, the detector module shouldbe removed from the instrument, andfollowed by appropriate service (see jetcleaning procedure on page 53).
Occasionally, the transfer line fused silicaliner between the column and FPD modulemust be inspected, cleaned and/or replaced.
Flame Ignition Problems
If the FPD flame won’t light or stay lit:
� Be sure there is a problem. Ignition is bestconfirmed by holding a mirror or shinysurface near the aluminum exhaust tube,with the rubber drip tube removed, andobserve condensation if the flame is lit.
� Check Lit Offset. If it is zero, autoignitionis turned off. If it is too large, the GC willnot know that the flame is lit and willshut down the detector.
� Increase the air supply pressure to thepneumatics module. This makes theflame easier to light but does not affectthe air flow rate setpoint.
� If the flame doesn’t light at all, check theglow plug circuit. Observe the visualdisplay, which will momentarily go togreater than 65500 counts when theflame lights. If the display doesn’tchange, check the pin connections at theprinted circuit board, the lead connectionon the glow plug and the appropriate 5Afuse on the GC main circuit board.
� The flame is easier to light at higherdetector temperatures.
� Under some operating conditions, theflame may be more easily lit with therubber drip tube removed. After lightingthe flame, reinstall the drip tube.
� If the flame still won’t light, there couldbe a large leak in the system. This resultsin measured flow rates being differentfrom actual flow rates, causing non-idealignition conditions. Thoroughly leakcheck the whole system.
Flame Conditions & Gas Flows
The flame conditions are critical tosuccessful operation. Since the detectionzone is above the flame, the gas flows andjet diameter must be optimized so thatcomponents burned (activated) in the flamewill emit in the detection zone.
Gas flows are also critical for optimizedselectivity and sensitivity. The most criticalparameters are the hydrogen/air orhydrogen/oxygen ratio, and the total gasflow, which effects flame temperature.
50 www.agilent.com/chem
DETECTORS
Flame Photometric Detector (FPD)
HELPFUL HINT: Install the correct opticalfilter, depending on the choice of Sulfur orPhosphorus mode. For Sulfur Mode, usethe 393 nanometer filter. For PhosphorusMode, use the 525 nanometer filter.
www.agilent.com/chem 51
Item Description Unit Part No.
1 Exit tube assembly 19256-60700
2 Nut, brass, 1/4 in. 10/pk 5180-4105
4 Weldment, block 19256-80560
5 O-ring, ignitor, Kalrez 0905-1102
6 Spacer, ignitor 19256-20590
7 Glow plug 0854-0141
8 Ignitor cable assembly (6890 only) G1535-60600
9 Gasket, heat shield 19256-80040
10 Window, first heat shield 19256-80030
11 Disk, heat shield 19256-20580
12 Coupling, SS 19256-20550
14 Screw, M3 x 12 (4 required) 0515-0911
15 Clamp 19256-00090
16 O-ring, inner window 12/pk 5061-5886
17 Window, second heat shield 19256-80060
18 O-ring, outer window 12/pk 5061-5891
19 Flange adapter 19256-20510
20 Flange ring 19256-00200
21 O-ring, Viton, 1.239 in. id 12/pk 5061-5890
Adapter weldment, 1/8 in. columns 19256-80590
Adapter weldment, capillary 19256-80570
Start-up kit (5890 only) 19256-60500
FPD O-ring (5890 only) 12/pk 5061-5867
Liner/ferrule kit 19256-60590
Sulfur filter 19256-80000
Phosphorus filter 19256-80010
Kalrez O-ring, size 2-002 0905-1101
Kalrez O-ring, size 2-011 0905-1103
Fluorocarbon Elastomer O-ring, brown, 0.926 in. id 12/pk 5061-5889
FPD Performance Evaluation Sample: Solution of 20 ng/mL (20 ppm) dodecanethiol and tributylphosphate in isooctane, 3 ampoules 19305-60580
DETECTORS
1
2
3
4
56
7
8
16
910
11
12
1314
15
1718
19
20
21
6890/5890 FPD Supplies
Hardware Problems
If the flame goes out or will not light:
� Check the column flow rate. It may be toohigh. Decrease the flow rate or pressure.Switch to a more restrictive column(longer or with a smaller id). If you mustuse a large id column, turn off the carrierflow long enough to allow the FID to light.Check for partially or completely plugged jet.
� Check that the right type of jet is installedfor the column you are using.
� Injecting large volumes of aromaticsolvent can cause the flame to go out.Switch to a nonaromatic solvent.
� The lit offset value may be too low or toohigh. Adjust the value.
Cleaning & Replacement
Even with normal use, deposits develop inthe jet and detector (usually white silicafrom column bleed or black carbonaceoussoot). These deposits reduce sensitivityand cause chromatographic noise andspikes. Although you can clean the jet, it isusually more practical to replace dirty jetswith new ones. If you do clean the jet, becareful not to scratch the jet internally;scratches will ruin the jet.
Flame Ionization Detectors require littlemaintenance to keep them performing atsatisfactory levels. The primary task is tooccasionally measure hydrogen, air andmakeup gas flows. They can drift over timeor be changed unintentionally withoutknowledge of it occurring. Each gas flowshould be independently measured toobtain the most accurate values.
Condensation
Since the FID combustion process results in water formation, the detectortemperature must be kept above 100˚C toprevent condensation. Such condensation,especially when combined with chlorinatedsolvents or samples, causes corrosion andsensitivity loss.
52 www.agilent.com/chem
DETECTORS
Flame Ionization Detector (FID)
FID Cleaning Kit
Igniter Glow Plug Assembly
Collector Assembly
Collector Body
FID Jets
FID Ferrules
Plugged FID jet
Description Unit Part No.
6890/6850 Supplies
Collector insulator G1531-20700
Collector body G1531-20690
FID collector assembly* G1531-60690
Detector insulation assembly G1531-20700
FID ignitor cable G1531-60680
Collector Housing G1531-20740
5890 Supplies
Collector assembly* 19231-60690
Upper collector insulator 19231-20970
Collector body 19231-20960
Hastelloy collector 19231-21080
Lower collector insulator 19231-20950
6890/6850/5890 Common Supplies
PTFE chimney (optional) 19231-21050
Collector nut 19231-20940
Spring washer 10/pk 5181-3311
Ignitor castle 19231-20910
Hastelloy Ignitor Castle 19231-21060
Ignitor glow plug assembly 19231-60680
FID collector cleaning brush 2/pk 8710-1346
FID retainer nut wrench (5880, 5890, 6890) 19301-00150
1/4 in. Nut Driver for FID jet-drilled shaft 8710-1561
FID flow measuring insert 19301-60660
O-rings for flow measuring insert 12/pk 5080-4978
FID Performance evaluation sample kit, 0.03% C14, C15, and C16 normalalkanes in hexane 18710-60170
Jet cleaning wire for 0.03 in. id jet 5/pk 5180-4150
Jet cleaning wire for Series 530 mm and 0.018 in. id jet 5/pk 5180-4152
FID cleaning kit 9301-0985
*Assembly Contains: Gasket, Ignitor Castle, Ignitor Glow Plug Assembly, Spring Washer-WavyCollector, Housing, Mount, Nut, Body, Spanner Nut, Insulator (upper and lower)
Flame Ionization Detector (FID) Supplies
www.agilent.com/chem 53
DETECTORS
Only a small sampling of FID supplies are shown here. For a complete selection, see the Agilent 2002-2003 Chromatography & Spectroscopy Supplies Reference Guide.
Jet Cleaning Procedure (using Agilent’s FID Cleaning Kit #9301-0985)
1. Run a cleaning wire through the top ofthe jet. Run it back and forth a few timesuntil it moves smoothly. Be careful not toscratch the jet. (Do not force too large awire or probe into the jet opening or theopening will become distorted. A loss ofsensitivity, poor peak shape and/orlighting difficulties may result if theopening is deformed.)
2. Fill an ultrasonic cleaning bath withaqueous detergent, and place the jet inthe bath. Sonicate for five minutes.
3. Use a jet reamer to clean the inside ofthe jet.
4. Sonicate again for five minutes.
NOTE: From this point on, handle the partsonly with forceps!
5. Remove the jet from the bath and rinse itthoroughly, first with hot tap water andthen with a small amount of GC-grademethanol.
6. Blow the jet dry with a burst of thecompressed air or nitrogen, and thenplace the jet on a paper towel and allowit to air dry.
54 www.agilent.com/chem
DETECTORS
Description Length (mm) Part No.
Jets for capillary dedicated FID (6890 only)
Capillary jet (0.011 in./0.29 mm id tip) 48 G1531-80560
High-temperature jet (SimDIS 0.018 in. id tip) 48 G1531-80620
Adaptable FID (6890/6850/5890)
Capillary 0.53 mm jet (0.011 in. id tip) 61.5 19244-80560
Packed (0.018 in. id tip) 63.5 18710-20119
Packed (0.030 in. id tip) 63.5 18789-80070
0.53 mm high temp (0.018 in. id tip) for SimDIS 61.5 19244-80620
FID Jets
To view a video on FID column installation, jet replacement,collector maintenance, or ignitor replacement,
visit www.agilent.com/chem/supplies, click on “How-to Video” under the Reference Library.
Agilent FID Jets (from top to bottom): Dedicatedcapillary, Adaptable capillary, Adaptable packed
HELPFUL HINT: Different size jets are available to optimize flame shape for capillarycolumns, or reduce contamination build-up for high molecular weight eluates. Usually,small bore jets produce the greatest signal, but can plug up or contaminate more easilyrelative to large jets, so compromise may be necessary.
“Of course we have all the rightconsumables and supplies you need
to keep your Agilent GC systemrunning at peak performance. But it
doesn’t stop there. We want toextend our knowledge. Our expertise.
And our technical support.”
Hwee-Sian TanApplication Manager
Service & Support
Every Agilent GC system is backed by awealth of knowledge, all at your fingertips.Tap our 35 years of instrument expertiseand applications knowledge by phone, inperson, in print, or on-line. Contact us for a variety of service and repair options fromtelephone support, on-site repair, evenproduct exchange. Take advantage of our industry leading training courses to help increase the overall knowledge inyour lab.
Any way you want, you get the full supportof Agilent expertise and service with everyGC system.
www.agilent.com/chem 55
Technical Support Consultation
Have a technical GC column, method, ortroubleshooting question? Agilent’s Technical GC Column experts are available to answer your questions by phone, fax or e-mail for free.With years of experience in running samples,developing methods and troubleshooting GCsystems, our chemists are promptly able to helpyou consistently achieve excellent performanceand high productivity in your lab.
On-line: www.agilent.com/chem, choose Technical Support, then select “Ask our Technical Support Specialist.”
Expert Training from the GC Experts
Well trained lab professionals keepproductivity high, minimize the number of errors and reruns, and expandchromatography capabilities. With experttraining that gives you on-site expertise for troubleshooting and maintenance, your lab will run at peak performance.
GC Training
Agilent’s training courses for gaschromatography helps new andexperienced lab professionals learn proper and efficient ways to use analytical instruments and software. These ISO-registered courses also targetthose who want to broaden or sharpentheir troubleshooting and maintenance, and system operation skills. ContactAgilent today for more information aboutour training and other Support Services. Or visit www.agilent.com/chem and select “Education.”
GC System Operation Training
Course #H5308A introduces thefundamental concepts of gaschromatography and the operation of the Agilent 6890 GC using the AgilentChemStation for GC and capillary columns.This five-day hands-on course is designedfor the new GC operator who is responsiblefor routine sample analysis. It coverseverything from inlets, columns, anddetectors to data analysis and reporting.For more information on all Agilent Trainingofferings, visit www.agilent.com/chem andselect “Education.”
GC Troubleshooting/Maintenance Training
Agilent offers a four-day hands-on courseproviding practical information fortroubleshooting and maintenance for thecomplete Agilent Gas ChromatographySystem. It’s designed for the professionalwith a fundamental GC knowledge and who is responsible for troubleshooting and maintenance. Learn how preventivemaintenance can ensure the long-termreliability and proper operation of yourAgilent GC system. For more information on all Agilent Training offerings, visitwww.agilent.com/chem and select“Education.”
� Course #H5308A (for Series 6890)
� Course #H4001A (for Series 5890)
56 www.agilent.com/chem
SERVICE & SUPPORT
Expert Training, Service & Support
Your Choice for Instrument
Maintenance & Repair
Contact the Agilent experts for GCmaintenance and repair. We can bring ourtechnical experts to your facility, or you canship your instrument to us. We’ll even sendan exchange instrument* to keep you upand running.
* for select instruments only
Preventive Maintenance & Repair At Your Site
With an Agilent Support Service Contract,an Agilent service professional will come to your site for repair. You even get a choice of response times to keep repairscost-efficient. We’ll even come to your site to conduct a thorough preventivemaintenance, to keep your instrumentsrunning at peak performance. Contact Agilent today, or visitwww.agilent.com/chem, for moreinformation about these and other Support Services.
Expert Instrument Repair
You can keep your repair costs low andmaintain productivity with a choice of off-site repair options. Just ship yourinstrument to an Agilent AnalyticalCustomer Service Center. We’ll diagnosethe problem, repair the unit and return it to you (usually within five days). Or ifmaximum uptime is critical, ask about ourInstrument Exchange program. Agilent willship you a replacement instrument to keepuntil your unit is repaired and returned.
Service Contracts Offer Big Rewards
Sign up for Agilent’s Chemical AnalysisService Contract** today and you’ll enjoyindustry-leading product support andservice. You’ll also get regular specialoffers, including:
� exclusive introductory offers on newproducts and services
� incentives for PerfectFit supplies to keepyour lab running at peak performance
� notification and advice on replacementstrategies for older instrumentation
� discounts on selected Agilent trainingcourses
Sign up today and get access to exclusiveareas of the Agilent web site providingvaluable instrument and applicationinformation, instructional videos forinstrument maintenance, and easy on-lineordering. We’ll also e-mail regularreminders about product development, andupcoming exclusive rewards. Sign up todayat www.agilent.com/chem/rewards.
** Contract covers travel, parts, labor for Agilentservice professional plus expert telephone assistanceto isolate and resolve hardware problems.
Bundled Service to Save You Money
Agilent offers industry-specific ServiceBundles for the Petrochemical andPharmaceutical industries. Service Bundlescontain essential services to keep yourchemical analysis instruments in topcondition for dependable operation. You’llget telephone support, on-site and off-siteinstrument repair including exchangeinstruments, as well as on-site preventivemaintenance services, all for less than thecost of purchasing each service separately.Contact Agilent today for more informationabout these and other Support Services.
www.agilent.com/chem 57
SERVICE & SUPPORT
Create Your Own Service Bundle
Contact Agilent today to configure apackage of support services to meet yourlab’s needs — hardware maintenance,troubleshooting, repair, support, andpreventive maintenance. Just let us knowwhat you need and we’ll configure apackage for you. Contact Agilent today for more information about our SupportServices and Contracts.
Operational Re-Qualification After Repair
For instruments that require qualification,Agilent’s Re-qualification After Repairservice verifies that a system is stillperforming to Agilent’s operationalspecifications after a repair, includingdocumentation that meets auditrequirements. Contact Agilent today formore information about this and otherservice contracts.
�
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Tap Agilent’s extensive GC knowledge any time. Just give us a call to discusshardware, software, applications concernsor just basic GC operation techniques. Andbe sure to subscribe to our information-packed magazine.
Software Support
Only Agilent can provide expert assistanceto isolate and resolve software problems.We’ll provide telephone assistance fromhighly trained experts. We’ll provide allenhancements to the original chemicalanalysis software purchased. We’ll evensend you Software Bulletins to let youknow about ongoing issues andrecommended workarounds. ContactAgilent today for more information aboutthese and other Support Services.
Hardware Support
Agilent’s highly trained technical staff isjust a phone call away to offer you basichardware troubleshooting, operationassistance, instrument and systemconfiguration, and remote diagnostics. Callus toll-free today, or submit your questionon-line at www.agilent.com/chem.
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For a wealth of GC knowledge any time,visit www.agilent.com/chem. You’ll find:
� Ask our Technical Support Specialists(send an on-line question to a technicalSupport Chemist)
� Frequently Asked Questions (answers to the most commonly asked technicalquestions about Agilent instruments and supplies)
� Technical Support Assistance (a logical,step-by-step approach to help you solvecommon problems)
� Technical Document Library (a searchablecollection of service and supportdocuments)
� Chromatogram Library (a searchablecollection of GC, LC, and CEchromatograms – nearly a thousandchemical compounds)
� Product Support Literature (includingOperating Manuals and InstallationGuides)
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� Software Status Bulletins (updates onrecommended software workarounds)
Plus, a host of information and features tomake ordering easier and faster.
58 www.agilent.com/chem
SERVICE & SUPPORT
Open inside cover for:
GC SystemRecommendedMaintenanceSchedule
GC System Recommended Maintenance
Gas ManagementITEM TYPICAL SCHEDULE ACTIONS/COMMENTS
Gas purifiers Every 6-12 months Replacement schedule is based on capacity and grade of gases. (carrier gas & In general, replace non-indicating traps every 6-12 months or when detector gas) indicating traps start to change color. Replace indicating traps when
indicating material is spent.
Split vent trap Every 6 months* Replace.
Flowmeter Every 1-2 years Re-calibrate electronic flowmeters – follow recommended schedule forcalibration the unit (shown on calibration certificate).
Sample Introduction and InletsITEM TYPICAL SCHEDULE ACTIONS/COMMENTS
Syringes Every 3 months* Replace syringe if dirt is noticeable in the syringe, if it cannot beand/or syringe cleaned, if the plunger doesn’t slide easily, or if clogged. Replace needles needle if septa wear is abnormal or the needle becomes clogged.
Inlet liner Weekly* Check often. Replace when dirt is visible in the liner or if chromatography is degraded.
Liner O-rings Monthly* Replace with liner or with signs of wear.
Inlet septum Daily* Check often. Replace when signs of deterioration are visible (gaping holes, fragments in inlet liner, poor chromatography, low column pressure, etc.).
Inlet Hardware Every 6 months Check for leaks and clean.
Every year Check parts and replace when parts are worn, scratched, or broken.
Remember, the downtime for scheduled
maintenance is always less disruptive
than the downtime for unscheduled
maintenance/troubleshooting!
www.agilent.com/chem
Schedule
ColumnsITEM TYPICAL SCHEDULE ACTIONS/COMMENTS
Front-end Weekly – monthly* Remove 1 ⁄2-1 meter from the front of the column when experiencing Maintenance chromatographic problems (peak tailing, decreased sensitivity, retention
time changes, etc.). Replace inlet liner, septum and clean inlet as necessary. Guard column may be useful for increasing column lifetime.
Solvent rinse As needed When chromatography degradation is due to column contamination. Only for bonded and cross-linked phases.
Replacement As needed When trimming and/or solvent rinsing no longer return chromatographicperformance.
Ferrules Replace ferrules when changing columns and inlet/detector parts.
DetectorsITEM TYPICAL SCHEDULE ACTIONS/COMMENTS
FID/NPD Jets As needed Clean when deposits are present. Replace when they become scratched, & Collector bent or damaged, or when having difficulty lighting FID or keeping flame lit.
NPD Bead As needed Replace when signal drifts or there is a dramatic change in sensitivity.
FID Every 6 months Measure hydrogen, air, and makeup gas flows.
TCD As needed Thermally clean by “baking-out” when a wandering baseline, increased noise, or a change in response is present. Replace when thermal cleaning does not resolve the problem.
ECD Every 6 months Wipe test.As needed Thermally clean by “baking-out” when baseline is noisy, or the
output value is abnormally high. Replace when thermal cleaning does not resolve the problem.
FPD Every 6 months Measure hydrogen, air, and makeup gas flows.As needed Clean/replace FPD windows, and seals when detector sensitivity
is reduced.
*Schedule is an approximation of average usage requirements. Frequency may vary widely based upon application and sample type.