Determination by Isotope Ratio Mass Spectrometry of the Absolute Isotope Amount Fractions of Oxygen and Nitrogen in Nitrous Oxide

The significant interest related to atmospheric Nitrous oxide as a greenhouse gas and as a tool to regulate the Ozone concentration is well-known and requires to define a precise budget in the atmosphere for this gas. Therefore, the isotopic measurements are proposed to become the necessary additional instrument to better quantify this budget. The lack of a real comparability tool for the disparate Nitrous oxide isotopic measurement done required to start the work related to the development of a Reference material for Nitrogen and Oxygen in this gas. A measurement procedure for the complete isotope characterization of atmospheric Nitrous oxide sample has been developed and applied to establish a first Reference material for this gas. The whole work has been based on the peculiar instrumental capabilities of "Avogadro" MAT 271IRMS. Additional hardware and software improvement has been done for this mass spectrometer to apply the proposed method.