The importance of nitrous acid

OH and HO2 (HOX) radicals are important oxidants in the tropospheric atmosphere, directly inducing atmospheric photochemical processes and playing an important role in the formation of atmospheric pollution. Accurately understanding the source sink processes of free radicals in the atmospheric troposphere can help clarify the formation mechanism of atmospheric compound pollution. Research has shown that the contribution of nitrous acid to OH radicals is relatively large compared to other OH radical precursors, up to 60%. In addition, the generation and consumption of nitrous acid are also components of the atmospheric nitrogen cycle.

Accurately identifying and quantifying the characteristics and sources of nitrous acid is particularly important for studying the formation mechanism of atmospheric pollution and improving the simulation performance of models. More and more measurements of nitrous acid need to be invested in field observations to better understand the transformation process of nitrous acid in atmospheric chemistry and the impact of atmospheric chemical products it brings.

Principles of Instrument Measurement

This instrument applies wet chemical sampling and optical detection methods for in-situ online measurement of nitrous acid content in gases. The measured nitrous acid is converted into azide through chemical methods, and the concentration of nitrous acid is determined by measuring the light absorption along a long path.