Does anyone perform permanent gas analysis using GC-MS?

[Heikki]

We currently utilize TCD as the detector for analyzing H2, O2, N2, CH4, CO2 and C2H6. I'm interested if anyone has found the means to do the same thing using mass spec. as detector?

To aim is to acquire a very rapid method to do gas analysis.

[AICMM]

Heikki,

You mean RGA or GC/MS system? If GC/MS, have fun. I worked side by side with a customer who insisted on Plot column with MS and I used standard sieve with HID and I was running (much better than MS) in about 1/4 of the time. Problem is, MS is always trying to pull in outside air (vacuum system) so N2, O2 and argon are always an issue. Compound that with fact that many MS's don't like flows above a mL a minute and Plot columns do and you have a quandry. You might be able to split the column exhaust if your levels are high enough and give the plot good flows... Plus, CO and N2 have the same ions....

I am sure there are process MS people that can help you out if you choose to go this route. Perhaps Extrel, Onix, Siemens....

So, how fast is fast? What is the balance gas? What are the detection limits and what is the operating range?

Best regards.

[Ron]

I agree with AICMM, GCMS is not necessarily the way to go for gas analysis. You still need chromatographic separation, and even though most recent mass spectrometers can handle flow rates above 1 mL/min they can't handle megabore plot columns unless they are at least 60 m long and operated at a higher than ideal temperature. Mass spectrometers are great for some applications, but conventional GC detectors are still better for other applications.

[CE Instruments]

Using an MS will not give you a faster analysis time. For some really fast analysis look to a CompactGC with either TCD or PDD.
www.gas-site.com
We are suppliers in the UK

[AICMM]

Heikki,

While I don't want to withdraw any of my earlier comments about the challenge of fixed gases by MS, I would offer one other possibility. It might be possible to use a 0.32 Plot (as noted by Krickos in another post) and split the effluent right before the MS. Hydrogen will still be very difficult with low AMU but you might be able to do the others. You would be required to split the sample so your sensitivity would suffer but if you have high concentrations it still might work

Best regards.