analyse humidity

[andrea]

Is it possibile to analyse humidity of the sample with a micro-GC?
The carrier gas is argon and the columns are:
1. CP-Sil (8 meters) (40°C, 90 kPa)
2. Moulsive (20 meters) (120 °C, 180 kPa)
3. ParaPlot Q (5 meters) (60°C, 110 kPa)

I'm interested in the ret-time of humidity and the specific (tempeture and pressure) of the column.
Thanks

[AICMM]

Andrea,

Has to be a thick film column (have done it with a CP-Sil8, at ppm levels) but the other question is what else is present. Water elutes relatively early on thick film -8 so if lots of air or other intereferant present, this might overwhelm the chromatogram. Also, TCD will not be all that sensitive so how much water are we talking about? Micro-TCD's are very sensitive but generally micro-GC's only shoot a little bit because the detectors are so sensitive so the ultimate detection limit is still generally very high...

Best regards,

AICMM

[andrea]

Ok, we are talking about 50-60% humidity at 1 atm and 60°C. The sample to analyze is not air, but syngas (dry composition: 70% H2, 20% CO2, 2% N2, 5% CH4, 3% CO) or natural gas and so air might not overwhelm the chromatogram of humidity.
Is it correct?

Best regards

Andrea