Yet another H2 carrier gas question

[mtorrey]

Greetings

We are thinking of getting a new GC/MS, probably Agilent 7820/5977, and I'm thinking of setting it up for H2 carrier gas since the supply of He is getting unreliable. Question is can I use ultra-pure cylinder gas instead of hydrogen generator? We use cylinder gas for a 6890/FID but I don't know if it is pure enough for GCMS.

Yes I know H2 generator the better option for a number of reasons but we don't have the capital for one.

TIA
Mike

[James_Ball]

I would think you would be ok unless you are doing some type of ultra trace analysis. So far I have had higher background signals whether using a generator or from a cylinder. I would place one of the indicating oxygen traps in the line which takes the O2 down to less than 1ppm just to be certain and plumb it using new precleaned stainless steel lines.

I think part of the problem we have encountered here is trying to switch to hydrogen on 10+ year old instruments that have had just about everything imaginable run through them. The hydrogen pulls our contaminates from every little hiding place there is in the system.