Janet,

We measure methane in soils, which is for the most part no different 
than methane in air. Methane concentrations can vary a lot though, 
and when sub-ambient can create quite a challenge if you don't gather 
enough sample (pull gas from the soil through a tube). CO 
concentrations can also be high, which is trouble if the measurement 
doesn't account for it.

Paul Eby
University of Victoria


At 04:52 PM 13/03/2006, you 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