RoomTemperatureManual Headspace Injection
1. Inthistechnique,thesampleisequilibratedoffline. TransfersampleintoacleanVOAvialuntilthevialishalf
full. Let itsetat room temperaturefor30minutes toanhour toequilibrate.
2. Loadorcreatea temperatureprogram for thecolumnoven.
3. Perform
DetectorSteps
1-4, thenproceedwith the followingsteps.
4. Fillaplasticmedicalsyringewiththevialheadspace. InjectthesampleintotheGCinjectionport,bypassing
thePurge&Trapconcentrator.
5. Begin theanalysisbypressing theRUNbuttonon theGCor thecomputerkeyboardspacebar.
Note:both thesamplevialand thesyringemaybeheatedfor the injectionofwarmheadspacesamples.
POPULAR CONFIGURATION GCs
BTEX & Environmental
General Operating Procedures continued
Disposable, sterile1mLsyringesareavailable inpackages
of100 fromAldrichundercatalognumberZ23072-3. 27gauge
precisionglideneedles inpackagesof100areavailableunder
catalognumberZ19237-6.
1-800-558-9260
40mL VOA vials are available from Eagle
Picherunderpartnumber140-40C/EP/ES.
1-800-331-7425
1. With theblackplastic lamphood inplaceon thePID lamp, turnON thePID lampcurrentwith the flip
switchon theGC’s frontcontrolpanel. Set thePIDcurrent to70 (=0.70ma)byadjusting theappropriate
trimpotsetpointon the topedgeof theGC’sfrontcontrolpanel. (Eachdetectorzone is labeledon thefront
controlpanelunderDETECTORPARAMETERS,withthecorrespondingtrimpotsetpointdirectlyaboveit.)
The lampshouldemitaviolet-colored lightvisibledown thecenterof the tube. Set thePID temperature to
150
o
C. Set thePIDgain toLOW.
2. TurnontheaircompressorusingtheswitchontheGC’sfrontcontrolpanel. NOTE:sincemostambientair
willnotcause interferencewith theDELCD, thebuilt-inaircompressor isappropriate formostanalytical
situations. However,ifyouaredoinganalysesinalabenvironmentwithlowlevelsofhalogenatedcompounds
in theambientair, theycancause theDELCD to losesensitivity,andfluctuations in the leveloforganics in
ambientairmaycauseadditionalbaselinenoise. Toavoid this,useclean,dry tankair.
3. Set theFIDhydrogenflow to25mL/min,and theFIDairflow to250mL/min. Thepressurerequiredfor
eachflowisprintedontherighthandsideoftheGCchassis. IgnitetheFIDbyholdinguptheignitorswitchfor
acoupleofsecondsuntilyouhearasmallPOP. Ensure that theflame is litbyholding theshinysurfaceofa
chromedwrenchtothetipofthecollectorelectrode;whentheflameislit,youshouldbeabletoseecondensation
on thewrench. Set theFIDgain toHIGH. If thepeaksaremore than20secondswideat thebase,use the
HIGHFILTEREDgainsetting. Ifyouwish tokeep the ignitorON topreventflameout,set the ignitorvoltage
to-750byadjusting the trimpoton theFLAMEIGNITEzone.
4. If aDELCDdetector is installed, set theDELCD reactor temperature setpoint to260 (=1000
o
C) by
adjustingtheappropriatetrimpot. TheDELCDwillheattoaround254andstabilize;theprotrudingendofthe
ceramic tubewillglowbright red in theheat. Set theDELCDgain toLOW.
5. When thesystemhasreached temperatureandeachdetector isdisplayingastablesignal,begin theanalysis
bypressing theRUNbuttonon the frontof theGCor thespacebaron thecomputerkeyboard.
Detector Steps
