Dear All, The Atmospheric Chemistry Group at the University of Wollongong uses FTIR spectroscopy for measurement of isotopic ratios of key atmospheric gases. Low resolution (1cm-1) FTIR spectroscopy has been used in field measurements of the vertical profile of del-13CO2 emitted from agricultural soils. High resolution (0.012cm-1) FTIR has been used to determine the intramolecular isotopic composition of N2O, that is del-15N14N16O and del-14N15N16O, and in the near future will be applied to the simultaneous measurement of del-CH3D and del-13CH4. We have published results highlighting the positionally dependent 15N fractionation during photolysis of N2O, for both photolysis in a laboratory and in-situ stratospheric measurements using a balloon borne FTIR spectrometer. Intramolecular isotopic analysis of N2O emitted from a fertilised crop under various soil moisture conditions is in progress. Some relevant publications are: Esler, M.B., D.W.T. Griffith, F. Turatti, S.R. Wilson, and T. Rahn, N2O concentration and flux measurements and complete isotope analysis using FTIR spectroscopy, Chemosphere: Global Change Science, 2, 445-454, 2000. Esler, M.B., D.W.T. Griffith, S.R. Wilson, and L.P. Steele, Precision trace gas analysis by FT-IR spectroscopy. 1. Simultaneous analysis of CO2, CH4, N2O, and CO in air, Analytical Chemistry, 72 (1), 206-215, 2000. Esler, M.B., D.W.T. Griffith, S.R. Wilson, and L.P. Steele, Precision trace gas analysis by FT-IR spectroscopy. 2. The C-13/C-12 isotope ratio of CO2, Analytical Chemistry, 72 (1), 216-221, 2000. Griffith, D.W.T., G.C. Toon, B. Sen, J.F. Blavier, and R.A. Toth, Vertical profiles of nitrous oxide isotopomer fractionation measured in the stratosphere, Geophysical Research Letters, 27 (16), 2485-2488, 2000. Turatti, F., D.W.T. Griffith, S.R. Wilson, M.B. Esler, T. Rahn, H. Zhang, and G.A. Blake, Positionally dependent 15N fractionation factors in the photolysis of N2O determined by high resolution FTIR spectroscopy, Geophysical Research Letters, 27 (16), 2489-2492, 2000. For a fuller description of our group's work, I encourage you to visit the Atmospheric Chemistry, University of Wollongong website on http://www.uow.edu.au/science/research/acrg/index.html. Regards, Fred Turatti ________________________ Federico (Fred) Turatti Department of Chemistry University of Wollongong NSW, 2522 Australia Ph +61 2 4221 4296 Fx +61 2 4221 4287