Dear Sergey,
If you can obtain a copy of  Wilson Orr and Curt M. White, Eds
"GEOCHEMISTRY OF SULFUR IN FOSSIL FUELS"
American Chemical Society Symposium Series No 429, you will find two papers
which should help.  One  by Erdem Idiz et al and looks at isotope
fractionation during pyrolysis of Monteray kerogens. The other paper by
Kiyosu et al shows large kinetic isotope effects for carbon during high
temperature oxidation of light hydrocarbon gases in flow systems and in
closed tube experiments
Roy Krouse

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> From: S.S.Assonov (Sergey Assonov) <[log in to unmask]>
> To: [log in to unmask]
> Subject: Vacuum oxidation of organic material
> Date: Thursday, September 11, 1997 5:43 AM
>
> Dear isotopists,
>
> Prof. C.T.PillingerUs lab have studied a methane isotopic composition in
lunar
> fines and interstellar diamond. This samples are fine powders and have a
large
> surface area. I found a huge terrestrial organic contamination which
produce
> methane during pyrolysis of samples with maximum release at 450-600 C. To
> remove or reduce this contamination I have tried to heat samples in
presence
> of O2 (without any metal parts). I found that temperatures of methane
release
> is significantly reduced, but the amount of methane is similar. Could
anyone
> give me references about uncompleted vacuum oxidation of organic
material,
> carbon fractionation during that and destroying of organic molecules in
> presence of oxygen.
>
> Thank you for your help!
> Sergey Assonov
>
>
> -------------------------------------------
> Dr S.S. Assonov
> Planetary Sciences Research Institute
> The Open University
> Walton Hall, Milton Keynes,
> MK7 6AA England
> Fax:  44 (01908) 655 910
> Tel:  44 (01908) 653 558
> -------------------------------------------