Secondary Organic Aerosol Formation by Self-Reactions of Methylglyoxal and Glyoxal in Evaporating Droplets
- 7 October 2009
- journal article
- research article
- Published by American Chemical Society (ACS) in Environmental Science & Technology
- Vol. 43 (21), 8184-8190
- https://doi.org/10.1021/es902152t
Abstract
Glyoxal and methylglyoxal are scavenged by clouds, where a fraction of these compounds are oxidized during the lifetime of the droplet. As a cloud droplet evaporates, the remaining glyoxal and methylglyoxal must either form low-volatility compounds such as oligomers and remain in the aerosol phase, or transfer back to the gas phase. A series of experiments on evaporating aqueous aerosol droplets indicates that over the atmospherically relevant concentration range for clouds and fog (4−1000 μM), 33 ± 11% of glyoxal and 19 ± 13% of methylglyoxal remains in the aerosol phase while the remainder evaporates. Measurements of aerosol density and time-dependent AMS signal changes are consistent with the formation of oligomers by each compound during the drying process. Unlike glyoxal, which forms acetal oligomers, exact mass AMS data indicates that the majority of methylglyoxal oligomers are formed by aldol condensation reactions, likely catalyzed by pyruvic acid, formed from methylglyoxal disproportionation. Our measurements of evaporation fractions can be used to estimate the global aerosol formation potential of glyoxal and methylglyoxal via self-reactions at 1 and 1.6 Tg C yr−1, respectively. This is a factor of 4 less than the SOA formed by these compounds if their uptake is assumed to be irreversible. However, these estimates are likely lower limits for their total aerosol formation potential because oxidants and amines will also react with glyoxal and methylglyoxal to form additional low-volatility products.Keywords
This publication has 44 references indexed in Scilit:
- Atmospheric condensed‐phase reactions of glyoxal with methylamineGeophysical Research Letters, 2009
- Products and Kinetics of the Liquid-Phase Reaction of Glyoxal Catalyzed by Ammonium Ions (NH4+)The Journal of Physical Chemistry A, 2008
- A missing sink for gas‐phase glyoxal in Mexico City: Formation of secondary organic aerosolGeophysical Research Letters, 2007
- The contribution of sulfuric acid and non‐volatile compounds on the growth of freshly formed atmospheric aerosolsGeophysical Research Letters, 2005
- New particle formation from photooxidation of diiodomethane (CH2I2)Journal of Geophysical Research: Atmospheres, 2003
- Oxidation of glyoxal initiated by OH in oxygenated aqueous solutionJournal of the Chemical Society, Faraday Transactions, 1997
- Retro-Aldol and Redox Reactions of Amadori Compounds: Mechanistic Studies with Variously Labeled d-[13C]GlucoseJournal of Agricultural and Food Chemistry, 1996
- Formaldehyde, glyoxal, and methylglyoxal in air and cloudwater at a rural mountain site in central VirginiaJournal of Geophysical Research: Atmospheres, 1995
- Intensive studies of Sierra Nevada cloudwater chemistry and its relationship to precursor aerosol and gas concentrationsAtmospheric Environment. Part A. General Topics, 1990
- Analysis of aldehydes in cloud- and fogwater samples by HPLC with a postcolumn reaction detectorEnvironmental Science & Technology, 1989