Title: | General Mechanism for Sulfate Radical Addition to Olefinic Volatile Organic Compounds in Secondary Organic Aerosol |
Author(s): | Ren H; Sedlak JA; Elrod MJ; |
Address: | "Department of Chemistry and Biochemistry, Oberlin College, Oberlin, Ohio 44074 United States" |
ISSN/ISBN: | 1520-5851 (Electronic) 0013-936X (Linking) |
Abstract: | "Previous laboratory studies have suggested that sulfate radical addition to olefinic biogenic volatile organic compounds (BVOCs) is a potential formation mechanism for some organosulfates detected in ambient secondary organic aerosol (SOA). However, these studies propose conflicting reaction products, possibly because laboratory dissolved oxygen levels did not accurately reflect atmospheric conditions. Additionally, these studies used analytical methods that could not definitively identify and quantify the structurally specific products. Here, we describe a method that allows for the study of the reaction of sulfate radicals and several olefinic precursors, including allyl alcohol (AA), methyl vinyl ketone (MVK), 2-methyl-3-buten-2-ol (MBO), and methacrolein (MA), with careful control of dissolved oxygen levels and using the isomer-specific nuclear magnetic resonance (NMR) method to definitively identify and quantify the reaction products. Specific mechanisms for each olefinic precursor were developed, as well as a generalized mechanism that can be used to predict the sulfate radical reaction pathways for any olefin. The product yield results indicate that this mechanism is dominated by carbon backbone fragmentation pathways: 61, 83, 79, and 100% for AA, MVK, MBO, and MA, respectively. Several of the observed organosulfate products have also been detected in field observations of SOA, which indicates the potential relevance of this mechanism in the atmosphere" |
Keywords: | Aerosols Alkenes Sulfates *Volatile Organic Compounds nuclear magnetic resonance secondary organic aerosol sulfate radicals; |
Notes: | "MedlineRen, He Sedlak, Jane A Elrod, Matthew J eng Research Support, Non-U.S. Gov't 2021/01/22 Environ Sci Technol. 2021 Feb 2; 55(3):1456-1465. doi: 10.1021/acs.est.0c05256. Epub 2021 Jan 21" |