Abstract
Measurable spectral regions of the open light path spectrometer developed by CRIEPI contain absorption bands of volatile organic compounds (VOC) which deeply relate to the formation of SPM that influences human health. In the report, we concentrated on the retrieval of 7 species of VOC, ozone, and sulfur dioxide. In the retrieval procedures, gas concentrations were determined by correlated linear least-squares fit, and a correction for the oxygen absorption structure was added to ensure higher accuracy of the retrieval results. For the evaluation of the retrieved concentrations, comparisons were carried out with gas concentrations that were simultaneously measured from directly trapped atmosphere. The results of the comparisons showed good correlations for all species excepting one VOC that existed as an undetectable concentration between the measurement periods. Furthermore, time variations of the retrieved VOC concentrations corresponded with those of the nitrogen oxide concentration of mobile exhaust emission are most likely the largest contributor.
