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gas injection
Posted: Fri May 15, 2009 11:01 pm
by che313
regularly 2uL of sample inject in GC - but when we want to inject gas directly how much we have to inject 1ml? 2ml? 5ml?
Posted: Fri May 15, 2009 11:05 pm
by chromatographer1
Most liquids will expand 200 to 2000 times the liquid volume to a gas volume, depending upon the temperatures and pressures involved.
Experiment and see.
Rodney George
consultant
Posted: Sat May 16, 2009 12:21 pm
by Consumer Products Guy
I agree: experiment. Oftentimes we inject 1 ml gas samples.
Posted: Tue May 19, 2009 1:18 pm
by larkl
I'd be very cautious if you're going to apply a liquid external standard calibration to a gas sample. It may not be impossible, but I wouldn't trust the results. Maybe this isn't what you're trying to do.
Posted: Fri May 22, 2009 1:13 pm
by Peter Apps
Ultimately how much you have to inject depends on the concentration (mass:volume) of the sample and the minimum detectable (with acceptable repeatability) quantity (mass) of the detector.
Peter