Claudia,

>I'm looking for literature on preparation and isotope analysis of C- and/or
>N-isotopes in soil gas samples (e.g. CH4, CO2, N2, N2O, H2S, BTX).

There is a book that has recently been published that should be useful for
anyone who is interested in soils and stable isotopes, entitled:

Mass Spectrometry of Soils (1996), editted by Boutton, T.W. and Yamasaki,
S.-I. Macrcel Dekker, Inc., New York.   The Chapter by Barrie A. and
Prosser S.J., Automated analysis of light-element stable isotopes by
isotope ratio mass spectrometry (p1-46), has a lot of info on sampling and
measuring soil gases.

Good luck.
Kevin


**********************************************************
Dr Kevin Faure
Department of Geochemistry
Geological Survey of Japan
1-1-3 Higashi
Tsukuba
Ibaraki 305
Japan

Tel. and Fax: +81-298-54-3726