Theory of Operation continued
POPULAR CONFIGURATION GCs
BTEX & Environmental
RoomTemperatureManual Headspace Injection
WhenmakingheadspaceinjectionswiththeBTEXorEnvironmentalGCsystems,thesampleisequilibrated
offlineat room temperature. It is then injectedbysyringe into theon-column injector. This technique is
basically thedirect injectionofsmallgassamples.
GasSampleConcentration
In thisTO-14 type technique, a largevolumeofgas ispushedbysyringeorpulledbyvacuumpump
through thedual traps. The trappedanalytesare thendesorbedandswept into thecolumn. If theGChas the
optionalvacuumpump interface, thepump isplugged into itandmaybecontrolledby thePeakSimpledata
systemusinganevent table.
Direct Injection
DirectinjectionwiththeBTEXorEnvironmentalGCsystemsissimpleandstraightforward. Thismethod
uses theon-column injector to inject thesampledirectly into thecolumn,bypassing theentirepurgeand trap
injectionsystem. Samplesizefor this technique is1mLor lessforgas,and5µLor lessfor liquid. Noevent
table isnecessary, justa temperatureprogramfor thecolumnoven.
VOAvialand1mLsyringewith27gauge
needle formanualheadspace injections
