Jump to main content
Jump to site search


High-accuracy and high-sensitivity spectroscopic measurement of dinitrogen pentoxide (N2O5) in an atmospheric simulation chamber using a quantum cascade laser

Author affiliations

Abstract

A spectroscopic instrument based on a mid-infrared external cavity quantum cascade laser (EC-QCL) was developed for high-accuracy measurements of dinitrogen pentoxide (N2O5) at the ppbv-level. A specific concentration retrieval algorithm was developed to remove, from the broadband absorption spectrum of N2O5, both etalon fringes resulting from the EC-QCL intrinsic structure and spectral interference lines of H2O vapour absorption, which led to a significant improvement in measurement accuracy and detection sensitivity (by a factor of 10), compared to using a traditional algorithm for gas concentration retrieval. The developed EC-QCL-based N2O5 sensing platform was evaluated by real-time tracking N2O5 concentration in its most important nocturnal tropospheric chemical reaction of NO3 + NO2 ↔ N2O5 in an atmospheric simulation chamber. Based on an optical absorption path-length of Leff = 70 m, a minimum detection limit of 15 ppbv was achieved with a 25 s integration time and it was down to 3 ppbv in 400 s. The equilibrium rate constant Keq involved in the above chemical reaction was determined with direct concentration measurements using the developed EC-QCL sensing platform, which was in good agreement with the theoretical value deduced from a referenced empirical formula under well controlled experimental conditions. The present work demonstrates the potential and the unique advantage of the use of a modern external cavity quantum cascade laser for applications in direct quantitative measurement of broadband absorption of key molecular species involved in chemical kinetic and climate-change related tropospheric chemistry.

Graphical abstract: High-accuracy and high-sensitivity spectroscopic measurement of dinitrogen pentoxide (N2O5) in an atmospheric simulation chamber using a quantum cascade laser

Back to tab navigation

Publication details

The article was received on 12 Jul 2017, accepted on 24 Aug 2017 and first published on 15 Sep 2017


Article type: Paper
DOI: 10.1039/C7AN01167A
Citation: Analyst, 2017, Advance Article
  •   Request permissions

    High-accuracy and high-sensitivity spectroscopic measurement of dinitrogen pentoxide (N2O5) in an atmospheric simulation chamber using a quantum cascade laser

    H. Yi, T. Wu, A. Lauraguais, V. Semenov, C. Coeur, A. Cassez, E. Fertein, X. Gao and W. Chen, Analyst, 2017, Advance Article , DOI: 10.1039/C7AN01167A

Search articles by author

Spotlight

Advertisements