An absolute calibration of the site preference of 15N isotopic fractionation in N2O using FTIR spectroscopy
Abstract
The bulk isotopic fractionation of 15N in nitrous oxide (N2O) provides a valuable diagnostic for the pathways by which N2O is formed and processed in the natural environment. As the two N atoms in N2O are chemically inequivalent and do not exchange, 15N fractionation can be different at the two different sites. The preference for 15N fractionation between the two sites provides a further valuable diagnostic for N2O processing, but its exploitation has been limited in part due to a lack of agreement in defining an absolute calibration of the site preference. Here we present an independent method for an absolute calibration of the 15N site preference based on high resolution FTIR spectroscopy of N2O. IR spectroscopy naturally distinguishes the two isotopomers as separate species, provides absolute calibrations for both isotopomers independently, and is completely independent of mass spectrometric measurements.
- Publication:
-
AGU Fall Meeting Abstracts
- Pub Date:
- December 2007
- Bibcode:
- 2007AGUFM.B43A0888G
- Keywords:
-
- 0452 Instruments and techniques;
- 0454 Isotopic composition and chemistry (1041;
- 4870);
- 0469 Nitrogen cycling;
- 0490 Trace gases