Aerosol formation and reaction pathways of atmospheric oxidation of dimethylsulfide

This paper concerns with three series of experiments about dimethylsulfide gas phase oxidation, carried out at increasing NOx level (< 20 ppb, 1 ppm, 10 ppm) to show the relation between the amounts of nitrogen oxides and the molar yields of sulfur containing products. DMSO, DMSO2, HCHO, HCOOH and S O2 were found as main reaction products. From these experiments and from pr eceding studies, a sensitive decrease in the quantity of total sulfur produ cts in aerosol phase is underlined. This result derives from the reaction o f NOx with CH3S(O)O-2 and CH3S(O)OO radicals, which leads to stable interme diates as methylsulphonylperoxynitrate, MSPN, with a characteristic PAN-lik e structure.