SO material formed by methylglyoxal in aqueous aerosol mimics -- Part 2

Atmospheric Chemistry and Physics Discussions This discussion paper is/has been under review for the journal Atmospheric Chemistry and Physics (ACP). Please refer to the corresponding final paper in ACP if available. Abstract We used chemical ionization mass spectrometry with a volatilization flow tube inlet (Aerosol-CIMS) to characterize secondary organic material formed by methylglyoxal with ammonium sulfate in aqueous aerosol mimics. Bulk reaction mixtures were diluted and atomized to form submicron aerosol particles. Organics were detected using 5 Aerosol-CIMS in positive and negative ion mode using I − and H 3 O + ·(H 2 O) n as reagent ions. The results are consistent with aldol condensation products, carbon-nitrogen species, sulfur-containing compounds, and oligomeric species up to 759 amu. These results support previous observations by us and others that ammonium sulfate plays a critical role in the SOA formation chemistry of dicarbonyl compounds.