Paul,

My understanding of running SO2 on an IRMS is that it would have a
detrimental effect on the ion source over time (i.e. because it is a
"sticky" gas you would be spending much more time cleaning the ion source
and related hardware); however, I do not know to what extent.  I do know
that when analysing SO2 you would want to convert as much stainless steel
plumbing to teflon which adds an error to any d15N measurements because of
the increased N2 background.  I would think that anyone trying to analyze
the other light element isotope compounds you mentioned (N,C,O,H)on 1
dedicated IRMS system would want to try to analyze d34S from sulfur
hexafluoride (which is a much "cleaner" gas to work with).  Has anyone
compared SO2 versus SF6 measurements on the same system (i.e. a Delta 253
or similar IRMS)?

Art

> Dear colleagues,
>
> I was just asked by someone who is setting up a lab how feasible it is to
> run mostly SO2 analysis on an isotope ratio mass spec, but also some O and
> D in water and N and C in organic material from a EA.  I don't do S
> analysis, but in the past my understand was that it was desirable to have
> a
> separate mass spectrometer for SO2 analysis if possible.  My understanding
> was that SO2 would gradually affect the source and the results for O in
> particular but possibly other more stable compounds would deteriorate
> compared to a system that does not run SO2.  However, with modern
> continuous flow systems perhaps this is not as great an issue.
>
> Any advice on this would be appreciated.
>
> Paul Brooks.
>


-- 
Art Kasson
Cornell Isotope Laboratory
Dept Ecology and Evolutionary Biology
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