Kai Chung Kwong, M. M. Chim, E. H. Hoffmann
Jul 17, 2018
Citations
0
Influential Citations
17
Citations
Journal
ACS Earth and Space Chemistry
Abstract
Methanesulfonic acid (CH3SO3H, MSA) is one of the major organosulfur acids formed from the photochemical oxidation of dimethyl sulfide (DMS) produced by oceanic phytoplankton. MSA can react with metal halides (e.g., sodium chloride) in ambient aerosols to form methanesulfonate salts (e.g., sodium methanesulfonate, CH3SO3Na). While the formation processes of MSA and its salts are reasonably well understood, their subsequent chemical transformations in the atmosphere are not fully resolved. MSA and its salts accumulate near the aerosol surface due to their surface activities, which make them available to heterogeneous oxidation at the gas–aerosol interface by oxidants such as hydroxyl (OH) radicals. In this work, the compositional changes of aerosol comprised of MSA and its sodium salt (CH3SO3Na) are measured following heterogeneous OH oxidation. An aerosol flow tube reactor is coupled with a soft atmospheric pressure ionization source (Direct Analysis in Real Time, DART) and a high-resolution mass spectrom...