Quantifying Isotopic Signatures of N2O Using Quantum Cascade Laser Absorption Spectroscopy

Authors

  • Kristýna Kantnerová Laboratory for Air Pollution / Environmental Technology, Empa – Swiss Federal Laboratories for Materials Science and Technology, Überlandstrasse 129, CH-8600 Dübendorf, Switzerland
  • Béla Tuzson Laboratory for Air Pollution / Environmental Technology, Empa – Swiss Federal Laboratories for Materials Science and Technology, Überlandstrasse 129, CH-8600 Dübendorf, Switzerland
  • Lukas Emmenegger Laboratory for Air Pollution / Environmental Technology, Empa – Swiss Federal Laboratories for Materials Science and Technology, Überlandstrasse 129, CH-8600 Dübendorf, Switzerland
  • Stefano M. Bernasconi Geological Institute, Department of Earth Sciences, ETH Zürich, Sonneggstrasse 5, CH-8092 Zürich, Switzerland
  • Joachim Mohn Laboratory for Air Pollution / Environmental Technology, Empa – Swiss Federal Laboratories for Materials Science and Technology, Überlandstrasse 129, CH-8600 Dübendorf, Switzerland joachim.mohn@empa.ch

DOI:

https://doi.org/10.2533/chimia.2019.232

Keywords:

Biogeochemical nitrogen cycle, Clumped isotopes, Greenhouse gas, Laser spectroscopy, Nitrous oxide

Abstract

Nitrous oxide, N2O, is the environmentally most relevant constituent of the biogeochemical nitrogen cycle. Human activities, e.g. the agricultural use of mineral fertilizers, accelerate nitrogen transformations, leading to higher emissions of this strong greenhouse gas. Investigating the stable isotopic composition of N2O provides a better understanding of formation mechanisms to disentangle its variable source and sink processes. Mid-infrared (mid-IR) laser spectroscopy is a highly attractive technique to analyze N2O isotopocules based on their specific ro-vibrational absorption characteristics. Specifically, quantum cascade laser absorption spectroscopy (QCLAS) in combination with preconcentration has shown to be powerful for simultaneous and high-precision analysis of the main N2O isotopocules. Recently, in the scope of my PhD project, we have been advancing this analytical technique for the analysis of the very rare doubly substituted N2O isotopic species 15N14N18O, 14N15N18O, and 15N15N16O, also known as clumped isotopes. Currently, we are investigating the potential of these novel isotopic tracers to track the complex N2O production and consumption pathways. Improved understanding of the nitrogen cycle will be a major step towards N2O emission reduction.

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Published

2019-04-24

How to Cite

[1]
K. Kantnerová, B. Tuzson, L. Emmenegger, S. M. Bernasconi, J. Mohn, Chimia 2019, 73, 232, DOI: 10.2533/chimia.2019.232.