I have not used syringes for isotope ratio gas collection, but we do use
nylon ones lubricated with vacuum grease, for gas concentration collection.
 The problem is that most plastic syringes diffuse gas very rapidly, and
even the nylon ones are only reliable for a most a few days.  I assume
glass syringes sealed with vacuum grease might work.

Paul Brooks.


At 08:41 AM 12/10/98 -0800, you wrote:
>QUESTION FOR ALL:
>
>We are thinking of using gas tight syringes configured with two way
>valves for the collection and storage of soil gas samples for
>isotopic abundance analysis of carbon, nitrogen and oxygen.  Anyone
>out there have any experience or recommendations as to this approach?
> Any advice would be much appreciated.
>
>Bill
>
>*******************************************************
>William L. Griffis
>Chemist
>Integrated Stable Isotope Research Facility (ISIRF)
>Terrestrial Plant Ecology Branch
>Western Ecology Division
>National Health and Environmental Effects
>Research Laboratory
>US Environmental Protection Agency
>200 SW 35th Street
>Corvallis, Oregon 97333
>Telephone:  541-754-4761   FAX:  541-754-4799
>E-mail:  [log in to unmask]
>*************************************************
>
>