Kinetics and Oligomer Products of the Multiphase Reactions of Hydroxyacetone with Atmospheric Amines, Ammonium Sulfate, and Cloud Processing DOI Creative Commons
David O. De Haan, Lelia N. Hawkins, Elyse A. Pennington

et al.

ACS Earth and Space Chemistry, Journal Year: 2024, Volume and Issue: 8(12), P. 2574 - 2586

Published: Dec. 6, 2024

Hydroxyacetone (HA) is an atmospheric oxidation product of isoprene and other organic precursors that can form brown carbon (BrC). Measured bulk aqueous-phase reaction rates HA with ammonium sulfate, methylamine, glycine suggest these reactions cannot compete hydroxyl radical oxidation. In cloud chamber photooxidation experiments either gaseous or particulate in the presence same N-containing species, BrC formation was minor, similar mass absorption coefficients at 365 nm (<0.05 m2 g-1). However, rapid changes observed aerosol volume gas-phase species concentrations lack not due to slow reactivity. Filter-based UHPLC/(+)ESI-HR-QTOFMS analysis revealed SOA became heavily oligomerized, average molecular masses ∼400 amu all cases. Oligomers contained, on average, 3.9 HA, 1.5 ammonia, 1.6 small aldehydes, including, descending order abundance, acetaldehyde, glycolaldehyde, glyoxal, methylglyoxal. PTR-ToF-MS confirmed production aldehydes. We identify C17H26O5, C10H22O9, C15H27NO7, C17H23NO5, C18H32N2O9 as potential tracer ions for oligomers. hypothesize efficient oligomerization without substantial negligible N-heterocycle (e.g., imidazoles/pyrazines) formation. While unlikely a significant source, it may contribute significantly aqueous

Language: Английский

Kinetics and Oligomer Products of the Multiphase Reactions of Hydroxyacetone with Atmospheric Amines, Ammonium Sulfate, and Cloud Processing DOI Creative Commons
David O. De Haan, Lelia N. Hawkins, Elyse A. Pennington

et al.

ACS Earth and Space Chemistry, Journal Year: 2024, Volume and Issue: 8(12), P. 2574 - 2586

Published: Dec. 6, 2024

Hydroxyacetone (HA) is an atmospheric oxidation product of isoprene and other organic precursors that can form brown carbon (BrC). Measured bulk aqueous-phase reaction rates HA with ammonium sulfate, methylamine, glycine suggest these reactions cannot compete hydroxyl radical oxidation. In cloud chamber photooxidation experiments either gaseous or particulate in the presence same N-containing species, BrC formation was minor, similar mass absorption coefficients at 365 nm (<0.05 m2 g-1). However, rapid changes observed aerosol volume gas-phase species concentrations lack not due to slow reactivity. Filter-based UHPLC/(+)ESI-HR-QTOFMS analysis revealed SOA became heavily oligomerized, average molecular masses ∼400 amu all cases. Oligomers contained, on average, 3.9 HA, 1.5 ammonia, 1.6 small aldehydes, including, descending order abundance, acetaldehyde, glycolaldehyde, glyoxal, methylglyoxal. PTR-ToF-MS confirmed production aldehydes. We identify C17H26O5, C10H22O9, C15H27NO7, C17H23NO5, C18H32N2O9 as potential tracer ions for oligomers. hypothesize efficient oligomerization without substantial negligible N-heterocycle (e.g., imidazoles/pyrazines) formation. While unlikely a significant source, it may contribute significantly aqueous

Language: Английский

Citations

0