With regard to the following :

I have used old carbon spectrograph rods soaked in platinum chloride for
the O2 - CO2 conversion on a BrF5 line.  I found that even with the
platinum catalyst that lower temperatures produced a more complete
conversion.  Some workers prefer to time the reaction, supposedly for
reproducibility, but I found it better to stop as soon as the pressure
starts to rise again.  This is because even tiny amounts of a non-reactive
gas, such as nitrogen, slow the process enormously.  As the impurities are
variable, the time is variable.  On that subject, you must have relatively
pure O2.  Otherwise it appears that the inert gas is swept to the freezing
surface in the LN2 and largely blocks freezing down of the CO2.  This
ultimately leads to substantial CO production.

Hliary S_W

At 12:54 24/01/01 +1300, you wrote:
>Dear Sergey and Kinga,
>
>you could surely use much higher temperature but with a catalyst (Pt wire, Pt
>solution), gaining much time. See the literature on O-isotopes in
silicates or
>anyone who knows that procedure.
>
>Peter B.
>
>c/ IGNS, Lower Hutt, New Zealand
>
Hilary Le Q. Stuart-Williams Ph.D.
(Climate, behaviour study and ecology using stable isotopes)
Research Officer - Stable Isotope Laboratory
School of Environmental Sciences, University of East Anglia
Norwich NR4 7TJ, England
Telephone 01603 593837 (Work), 01603 507719 (Fax)
 01603 503430 (Home)

More data at : www.uea.ac.uk/~sil/