measure trace level H2S with GC MS

[lemma]

We need to measure trace level of H2S in exhaled breath condensate (basically water) and plasma with GCMS. After a search of literature, we found two approaches. One is to measure H2S in the headspace of acidified solutions and the other is to derivatise H2S with PFBBr and measure the PFBBr-S-PFBBr with EI.

With the headspace approach, what column is best to use with such a volatile compound?We do not have a headspace autosampler. Will the result be reliable by using a syringe?

With the second approach, we only find one ref. Don't know how reliable it is either.

Any suggestion is highly appreciated!

[AICMM]

lemma,

Consider a thick film Carbowax. Your main problem is going to be reactivity of the H2S (no matter how you do this.) Your problem is compounded by the fact that the use of MS will limit the column choices you have because of flow and pressure constraints.

Best regards,

AICMM