Hi Janet,

I would echo Paul Eby's comments. Depending on your set-up, you will 
want to make sure that the CO and CO2 are removed from your samples 
prior to analysis. Also, I would suggest analyzing the soil gas on a 
GC/FID or GC/ECD to see if there are any other low molecular weight 
hydrocarbons in the soil gas. Under anaerobic/anoxic conditions, it is 
possible that the microbial community is generating other organic 
compounds in addition to CH4.

Yit

On Mar 13, 2006, at 4:52 PM, Janet Gabites wrote:

> We have been asked about running methane in soils for 13C. Does anyone 
> have techniques/information/warnings that they are willing to share? 
> We have a DeltaPLus with EA, DeltaPlusXL with gas bench, TC/EA, and 
> GC-GCC available.
>
> Thanks,
> Janet
>
> Janet Gabites,
> Stable Isotope Facility,
> Pacific Centre for Isotope and Geochemical Research,
> Department of Earth and Ocean Sciences,
> The University of British Columbia,
> Vancouver, B.C. V6T 1Z4
> ph 604-822-6654
> fax 604-822-6088
> http://www.eos.ubc.ca/research/pcigr/PCIGR.htm
>
"...I do not believe totality can be contained in language; my problem 
is what remains outside, the unwritten, the unwritable. " - Italo 
Calvino, If On a Winter's Night a Traveller

Yit Arn Teh, Ph.D.
Postdoctoral Scholar
Rhew Laboratory
Department of Geography
507 McCone Hall
University of California
Berkeley, CA 94720-4740

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