>Dear Isotopists:
>
>Does anyone know of a  reference regarding the ionization efficiency of
>O-32, O-33 and O-34 molecules during the isotopic ratio measurements of
>oxygen in a mass spectrometer?
>
>Thanks in advance,
>
>Supriyo
>
>
Hi,

From measuring isotope ratios on pure oxygen, I know that the ionization
efficiencies of the different isotopomeres of O2 are almost equal. That is,
the absolute ratios our IRMS gives are quite similar to the values expected
based on the "known" isotope abundancies.
If, however, you are interested in an accurate determination of the (small)
differences between these efficiencies, you will run into the BIG problems
of absolute isotopic abundance determination.

Hope this helps.

Regards,

Harro Meijer

dr. Harro A.J Meijer
Centrum voor IsotopenOnderzoek (CIO)
Nijenborgh 4
9747 AG  Groningen
Netherlands
tel +31-50-3634760
fax +31-50-3634738
e-mail [log in to unmask] or [log in to unmask]