Hydrogen Purity for GC-MS

[Oatsandbeans]

We are looking to get a MS for our GC. We currently use hydrogen from a generator. It has a desicant drier in it. I have read that these are not good enough for GC-MS and I need one with a Palladium drier. Is this really true or a ploy by the equipment suppliers to sell more gear? The work that we will be doing will not be trace analysis so a bit of baseline noise is not the end of the world.

[Peter Apps]

Helium is the usual carrier gas for GC-MS. Have you looked into the issues of using hydrogen instead ?

Peter

[James_Ball]

You could use an inline moisture trap to remove any residual moisture if needed.

Hydrogen will work as a carrier for MS if you are not doing compliance work. It does tend to give some reactions in the source with certain compounds. We tried it for doing EPA volatiles work and the only thing keeping us from using it was that when we did a tune check with Bromofluorobenzene we could not get mass 96 within the 5-9% versus mass 95 which is required by the methods. I did manage to get it down to about 12-15%, but that just isn't good enough for the EPA. For non-compliance work you should be able to use it.