Thanks for all kind suggestion and discussion.I have
learned a lot from your feedback. It seems that the
idea doesn't work on general mass spectrometer
configiration. If I had to do it by peak jumping, what
is the highest possible resolution I can get if I did
it for many times? For two gases in source, is there
any interference between N2 and Ar?(cause just as Dr.
Michalski said, O2 might have very obvious
interference with both N2 and Ar).whether such
interference can be calibrated by using standard?

Appreciate for all your help!

Best regards

Tao

--- Greg Michalski <[log in to unmask]> wrote:

> Tao,
>    In addition to the previous issues, if these are
> air samples and your 
> interested in the 1515 (30) your going to have
> significant interference 
> (relative to the 15 abundance) from 16O14N made in
> the source
> 
> greg
> 
> Quoting Tao Fang <[log in to unmask]>:
> 
> > Dear All:
> > 
> > I have a question on N2:Ar ratio measurement. Is
> it
> > possible to measure enriched N2 isotope (mass 29
> and
> > 30) by comparing with Ar peak? Whether all dual
> inlet
> > mass spectrometer can measure mass ratio of 29/40
> and
> > 30/40, just like 28/29 and 28/30? or any special
> > modification is necessary?
> > 
> > Any suggestion is welcomed!
> > 
> > Best regards
> > 
> > Tao
> > 
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