60
Conclusion
Analyses of volatile organic compounds –VOCs – generally require concentration of the
sample using dynamic headspace (purge and trap), which reducesmatrix effects and
increases sensitivity, relative to other extraction techniques. The concentrated sample is
transferred to the capillaryGC column. BecauseGC detectors operatewell with higher
flows (10mL/min.), wide-bore columns, 0.45mm ID to 0.53mm ID, are appropriate. GC/MS
instruments have the greatest sensitivity, but flow into theMS source cannot exceed
1mL/min. Thismakes narrow-bore columns, usually 0.18mm ID to 0.25mm ID, but up to
0.32mm ID, the preferred choice for GC/MS analysis. The column is plumbed through the
injection port to allow high desorb flows (>10mL/min.) and sample splitting at the injection
port (>10:1). Determining the type of stationary phase in the capillary column is amatter of
preference and requires an examination of conditions specific to the analysis to be per-
formed.
Information in this guide explainsmany of the factors to be considered in analyses ofVOCs,
but cannot anticipate every situation. If you have any questions regarding this guide, or your
particular application, please contact our Technical ServiceTeam via email at
or via phone at 800-356-1688 or 814-353-1300, ext. 4.
Recommended Products
Columns
Rtx
®
-502.2Columns...............................................................................................................61
Rtx
®
-Volatiles Columns..........................................................................................................61
Rtx
®
-624Columns..................................................................................................................61
Rtx
®
-VMSColumns...............................................................................................................61
Rtx
®
-VGCColumns...............................................................................................................62
Rtx
®
-VRXColumns...............................................................................................................62
Rtx
®
-1Columns......................................................................................................................62
GuardColumns&Transfer Lines ...................................................................................62, 63
Accessories
Connectors .......................................................................................................................20, 64
Direct InjectionLiner,Vu-Tight
®
...........................................................................................18
ELCDReactionTubes ...........................................................................................................29
ELCDTransfer Lines.............................................................................................................27
FIDJets ..................................................................................................................................25
Gas LeakDetector ...........................................................................................................36, 65
Gas PressureRegulator..........................................................................................................28
Inlet Liners forVolatilesAnalysis..........................................................................................65
Low-Volume Injectors......................................................................................................19, 63
MoistureControl Bypass Line...............................................................................................14
MSDSourceNut....................................................................................................................35
PIDLamps .............................................................................................................................24
SampleVials...........................................................................................................................65
Spargers, Purge andTrap.........................................................................................................9
Syringes for Purge andTrap ..................................................................................................64
Analytical ReferenceMaterials
502.2Mixes&Kits................................................................................................................68
601& 602Mixes&Kits .......................................................................................................68
624Mixes&Kits.............................................................................................................67, 68
8260Mixes&Kits...........................................................................................................66, 67
CLPVOCMixes&Kits...................................................................................................68-70
PVOC/GRO/BTEXMixes .....................................................................................................67
Note:
Many additional referencematerials, including custommixes, are available from
Restek. Please call us at 800-356-1688, or contact your Restek distributor; we’ll help you
findwhat you’re looking for.
