Document Type
Article
Publication Date
12-6-2024
Journal Title
ACS Earth and Space Chemistry
Volume Number
8
Issue Number
12
First Page
2574
Last Page
2586
DOI
https://doi.org/10.1021/acsearthspacechem.4c00237
Version
Publisher PDF: the final published version of the article, with professional formatting and typesetting
Creative Commons License
This work is licensed under a CC BY-NC-ND License.
Disciplines
Chemistry
Abstract
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 of HA with ammonium sulfate, methylamine, and glycine suggest that these reactions cannot compete with aqueous-phase hydroxyl radical oxidation. In cloud chamber photooxidation experiments with either gaseous or particulate HA in the presence of the same N-containing species, BrC formation was minor, with similar mass absorption coefficients at 365 nm (<0.05 m2 g–1). However, rapid changes observed in aerosol volume and gas-phase species concentrations suggest that the lack of BrC was not due to slow reactivity. Filter-based UHPLC/(+)ESI-HR-QTOFMS analysis revealed that the SOA became heavily oligomerized, with average molecular masses of ∼400 amu in all cases. Oligomers contained, on average, 3.9 HA, 1.5 ammonia, and 1.6 other small aldehydes, including, in descending order of abundance, acetaldehyde, glycolaldehyde, glyoxal, and methylglyoxal. PTR-ToF-MS confirmed the production of these aldehydes. We identify C17H26O5, C10H22O9, C15H27NO7, C17H23NO5, and C18H32N2O9 as potential tracer ions for HA oligomers. We hypothesize that efficient oligomerization without substantial BrC production is due to negligible N-heterocycle (e.g., imidazoles/pyrazines) formation. While HA photooxidation is unlikely a significant atmospheric BrC source, it may contribute significantly to aqueous SOA formation.
Digital USD Citation
De Haan, David O.; Hawkins, Leila Nahid; Pennington, Elyse A.; Walsh, Hannah G.; Rodriguez, Alyssa A.; Symons, Michael A.; Andretta, Alyssa D.; Rafla, Michael A.; Le, Chen; De Haan, Audrey C.; Cui, Tianqu; Surratt, Jason D.; Cazaunau, Mathieu; Pangui, Edouard; and Doussin, Jean-François, "Kinetics and Oligomer Products of the Multiphase Reactions of Hydroxyacetone with Atmospheric Amines, Ammonium Sulfate, and Cloud Processing" (2024). Chemistry and Biochemistry: Faculty Scholarship. 48.
https://digital.sandiego.edu/chemistry_facpub/48