Lars:

        I received your email re:  Precision of CO2 analysis and I will forward to
this email to the Isotope search committee.

Carmen
Administrative Assistant
for Human Resources
--------------
At 09:31 AM 6/16/99 +0200, you wrote:
>Dear all.
>I do breath analysis and find at present very poor precision at low (<0.5%)
>CO2 content.
>Routine performance for normal breath (3-5%) is still a S.D. of around
>0.2per mil delta.
>
>This figure get 10 times worse with 0.5% CO2 or less. Out VG Optima ugas is
>from 1992.
>Maybe it is simply getting old? (have not yet done the annual service...)
>
>I have a 50 ul sample loop, injected into a gas stream of around 25 ml/min
>onto the packed column.
>Did anyone try to inject more samples with a larger loop to improve results
>of low CO2 samples?
>Any comments appreciated
>               Lars Löfgren
>
>phone +46(0)31 7762381
>fax +46(0)31 7763711
>e-mail  [log in to unmask]
>phone home +46(0)304 675720
>
>Address:
>Astra Hässle
>Bioanalytical Chemistry AB2
>431 83 Mölndal
>SWEDEN
>
>