Barbara, (and others interested)

Neil Loader and I felt it was ultimately best to "feed" Mass Spectrometers
what they were made for, CO2 rather than CO (thus avoiding all the problems
associated with using CO).

Measuring CO2 rather than CO came as a necessity to Neil and I initially
since the Prism and Sira at the GIQR (Cambridge) are utilized regularly for
CO2 applications (leaving us no chance to try CO applications).

Based on my work with nickel pyrolysis bombs I anticipated that there was a
possibility of equilibrating CO and CO2 on-line within the right temperature
range (which eventually turned out to be true).

There really isn't any detour involved in our technique. As in CO
techniques, our pyrolysis products also pass through the reduction oven,
however, ours is filled with nickel powder at a temperature set between 500
and 600 C.

I guess our technique would be of most interest to those who don't have the
luxury of dedicating a MS soely to CO applications. It seems like a hassle
(at least to me) to keep converting your MS back and forth between CO and
CO2.

The proof for our paper (in press: Rapid Communications in Mass
Spectrometry) has just been mailed in so it should be out sometime this
fall.

As an additional note: when running organic materials, hydrogen is separated
off from the main flow through a membrane. This  provides the possibility of
running hydrogen isotopes using this technique in the future.

cheers, Bill

----- Original Message -----
From: Barbara Kornexl <[log in to unmask]>
To: <[log in to unmask]>
Sent: Thursday, August 05, 1999 7:50 AM
Subject: Re: 16O-18O ratios of nitrate - production of CO2


> Bill,
> I just wonder why you go on this detour and produce CO2 as a measuring
> gas... I checked with Rapid Commun Mass Spectrom but couldn't find your
> paper yet. Maybe you can explain shortly.
> Thanks
>
> Barbara
>
> ****************************************************************
> Dr. Barbara E. Kornexl
> UFZ - Umweltforschungzentrum Leipzig-Halle GmbH
> Sektion Analytik
> Permoserstr. 15
> D-04318 Leipzig
>
> Tel.:   ++49/341/235-   2252
> Fax:                    2625
> E-Mail: [log in to unmask]
> *********************************************************************
>