We have used Linweld HP CO2 for the last 13 years. We are now using 3% CO2 in helium Linweld certified.

Hope this helps.


"Geldern, Robert" <[log in to unmask]>
Sent by: Stable Isotope Geochemistry <[log in to unmask]>

04/19/2005 05:23 AM
Please respond to Stable Isotope Geochemistry

        To:        [log in to unmask]
        Subject:        Re: Water equilibration with CO2

> I would like to know what grade of CO2 people use when
> equilibrating waters
> for subsequent delta 18O analysis on a mass spec.

Our system (Finnigan GasbenchII) is running with CO2 4.5 (99.995) as
standard gas and a mix of He(5.0) + 0.5%CO2(4.5) for equilibration.


Robert van Geldern
Leibniz Institute for Applied Geosciences (GGA)
S3: Geochronology and Isotopehydrology
Stilleweg 2, 30655 Hannover, Germany
phone: +49-(0)511-643-2313 (office), -2539 (lab)
fax: +49-(0)511-643-3665
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