Greetings
You don't specify which chemical species your interested in, although I
suspect it is water!

For the record, we have done work on 13C/12C in CO2 (M.B. Esler, D.W.T.
Griffith, S.R. Wilson, and L.P. Steele, "Precision trace gas analysis by
FTIR spectroscopy 2. The 13C/12C isotope ratio in CO2". Analytical Chemistry
72, 216-221 (2000).) This uses low resolution (1cm-1) FTIR and can be run in
the field.

We have also done some work on 15N isotopomers in N2O. This work is carried
out at much higher resolution (0.012cm-1), but gives the position of the 15N
within the molecule  (F. Turatti, 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 UV photolysis of N2O determined by high resolution FTIR
spectroscopy". Geophys. Res. Lett. 27, 2489-2492 (2000). M.B. Esler, D.W.T.
Griffith, F. Turatti, S.R. Wilson, T. Rahn, and H. Zhang, "N2O concentration
and flux measurements and complete isotope characterisation using FTIR
spectroscopy". Chemosphere 2, 445-454 (2000).
Cheers
Stephen Wilson
+---------------------------------------------
Dr. Stephen Wilson, Chemistry Dept.
University of Wollongong, NSW, 2522, Aus.
E-mail: [log in to unmask]
Web: http://www.uow.edu.au/~swilson
Ph: 61 (02) 42213505, Fax: 61 (02) 4221 4287
+---------------------------------------------


-----Original Message-----
From: Stable Isotope Geochemistry [mailto:[log in to unmask]]On
Behalf Of Tom Johnson
Sent: Tuesday, 20 February 2001 3:20
To: [log in to unmask]
Subject: [ISOGEOCHEM] IR based isotope analyses


Dear All,
Quite some time ago, there were reports that isotope ratio measurement via
IR absorption was being developed.  Does anyone know what the state of the
art is, or can you tell me who to contact to find out?
-Tom Johnson
***********************
Thomas M. Johnson
Assistant Professor
Dept. of Geology
University of Illinois at Urban-Champaign
245 Natural History Bldg. MC-102
1301 W. Green St.
Urbana, IL  61801
(217) 244-2002
FAX (217) 244-4996
[log in to unmask]

Visit the Hydrogeology Program's web site: www.geology.uiuc.edu/Hydrogeology
************************