OH-initiated oxidation of DMS/DMSO: reaction products at high NOx levels.
Environ Pollut
; 127(3): 403-10, 2004.
Article
em En
| MEDLINE
| ID: mdl-14638301
ABSTRACT
Dimethylsulphide (DMS) gas phase oxidation with OH radicals was investigated by long path FT-IR spectroscopy and by ion chromatography (IC) and HPLC-MS2 to quantify the reaction products and evaluate heterogeneous processes. The experiments were performed considering two different NOx (NO2+NO) levels. The initial concentration of NO2 was varied from 24 ppbV (NOx=1 ppmV) to 953 ppbV (NOx=10 ppmV). Photolysis of H2O2 was used as the OH-radical source. SO2, dimethylsulphoxide (DMSO), dimethylsulphone (DMSO2), methanesulphonic acid (MSA), methanesulphinic acid (MSIA) and methane sulphonyl peroxynitrate (MSPN) were identified as the main sulphur-containing products. The results indicate that higher NOx levels play a significant role in the chemistry of CH3S(O)x radical, influencing both the SO2/MSPN ratio and the amount of the sulphur species in the condensed phase, and that the NO2/NO ratio could influence the trends in the molar yields of the different products. For this reason the NOx content results a limiting parameter when on measure DMS in atmospheric environment.
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Base de dados:
MEDLINE
Assunto principal:
Sulfetos
/
Monitoramento Ambiental
/
Radical Hidroxila
/
Poluentes Atmosféricos
Idioma:
En
Ano de publicação:
2004
Tipo de documento:
Article