Brown Carbon Production by Aqueous-Phase Interactions of Glyoxal and SO2

Author(s)

David O. De Haan, University of San DiegoFollow
Kevin Jansen, University of Colorado, Boulder
Alec D. Rynaski, University of San Diego
W. Ryan P. Sueme, University of San Diego
Ashley K. Torkelson, University of San Diego
Eric T. Czer, University of San Diego
Alexander K. Kim, University of San Diego
Michael A. Rafla, University of San Diego
Audrey C. De Haan, University of San Diego
Margaret A. Tolbert, University of Colorado, Boulder

Document Type

Article

Publication Date

3-31-2020

Journal Title

Environmental Science and Technology

First Page

1

Last Page

19

DOI

https://pubs.acs.org/doi/10.1021/acs.est.9b07852

Version

Pre-print: the initial article submitted to the journal for consideration (prior to peer review)

Disciplines

Chemistry | Environmental Chemistry

Abstract

Oxalic acid and sulfate salts are major components of aerosol particles. Here, we explore the potential for their respective precursor species, glyoxal and SO₂, to form atmospheric brown carbon via aqueous-phase reactions in a series of bulk aqueous and flow chamber aerosol experiments. In bulk aqueous solutions, UV- and visible-light-absorbing products are observed at pH 3–4 and 5–6, respectively, with small but detectable yields of hydroxyquinone and polyketone products formed, especially at pH 6. Hydroxymethanesulfonate (HMS), C₂, and C₃ sulfonates are major products detected by electrospray ionization mass spectrometry (ESI-MS) at pH 5. Past studies have assumed that the reaction of formaldehyde and sulfite was the only atmospheric source of HMS. In flow chamber experiments involving sulfite aerosol and gas-phase glyoxal with only 1 min residence times, significant aerosol growth is observed. Rapid brown carbon formation is seen with aqueous aerosol particles at >80% relative humidity (RH). Brown carbon formation slows at 50–60% RH and when the aerosol particles are acidified with sulfuric acid but stops entirely only under dry conditions. This chemistry may therefore contribute to brown carbon production in cloud-processed pollution plumes as oxidizing volatile organic compounds (VOCs) interact with SO₂ and water.

Notes

© 2020 American Chemical Society

Published in final form at:

De Haan, D. O.; Jansen, K.; Rynaski, A. D.; Sueme, W. R. P.; Torkelson, A. K.; Czer, E. T.; Kim, A. K.; Rafla, M. A.; De Haan, A. C.; Tolbert, M. A., Brown Carbon Production by Aqueous-Phase Interactions of Glyoxal and SO₂. Environ. Sci. Technol. 2020. doi: 10.1021/acs.est.9b07852

Digital USD Citation

De Haan, David O.; Jansen, Kevin; Rynaski, Alec D.; Sueme, W. Ryan P.; Torkelson, Ashley K.; Czer, Eric T.; Kim, Alexander K.; Rafla, Michael A.; De Haan, Audrey C.; and Tolbert, Margaret A., "Brown Carbon Production by Aqueous-Phase Interactions of Glyoxal and SO2" (2020). Chemistry and Biochemistry: Faculty Scholarship. 36.
https://digital.sandiego.edu/chemistry_facpub/36