Analysis of methane and carbon dioxide with GC/MS and FID

[thalita.c]

Hi everyone,

I'm new here and also to the field of chromatography, so please bear with me. I have a question that I couldn't clarify by searching online. I need to quantify the composition of a biogas, containing mainly CH4 and CO2. I have a gas chromatograph with a mass spectrometer and a FID detector. I've read that a TCD detector would be ideal, but I don't have one in the lab. Can I perform the analysis I need with the equipment I have? The equipment is a Shimadzu GCMS-QP2010 Ultra Gas Chromatograph-Mass Spectrometer and a Shimadzu FID-2010 Plus (with APC) - 220/230/240V Flame Ionization Detector.

Thank you!

[rb6banjo]

It would seem that if you have a MS detector, you should be able to do all of it with that - provided you have a column that will give you good chromatography/separation for those gases. Methane is m/z=16 and CO2 is m/z=44.

I do methane in biogas for my company with static headspace and an FID. They typically don't ask me for the CO2. If you don't have a mass spec., you pretty much need a TCD for CO2.

Agilent makes a GC system for this application. It's called a MicroGC 490 (I think). It has 2 columns in it for the various components in biogas and 2 TCD's.