| Title: | Isoprene Epoxydiol-Derived Sulfated and Nonsulfated Oligomers Suppress Particulate Mass Loss during Oxidative Aging of Secondary Organic Aerosol |
| Author(s): | Armstrong NC; Chen Y; Cui T; Zhang Y; Christensen C; Zhang Z; Turpin BJ; Chan MN; Gold A; Ault AP; Surratt JD; |
| Address: | "Department of Environmental Sciences and Engineering, Gillings School of Global Public Health, The University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, United States. Department of Chemistry, College of Arts and Sciences, The University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, United States. Earth System Science Programme, Faculty of Science, The Chinese University of Hong Kong, Kowloon, Hong Kong 999077, China. Department of Chemistry, University of Michigan, Ann Arbor, Michigan 48109, United States" |
| ISSN/ISBN: | 1520-5851 (Electronic) 0013-936X (Linking) |
| Abstract: | "Acid-driven multiphase chemistry of isoprene epoxydiols (IEPOX) with inorganic sulfate aerosols contributes substantially to secondary organic aerosol (SOA) formation, which constitutes a large mass fraction of atmospheric fine particulate matter (PM(2.5)). However, the atmospheric chemical sinks of freshly generated IEPOX-SOA particles remain unclear. We examined the role of heterogeneous oxidation of freshly generated IEPOX-SOA particles by gas-phase hydroxyl radical ((*)OH) under dark conditions as one potential atmospheric sink. After 4 h of gas-phase (*)OH exposure ( approximately 3 x 10(8) molecules cm(-3)), chemical changes in smog chamber-generated IEPOX-SOA particles were assessed by hydrophilic interaction liquid chromatography coupled with electrospray ionization high-resolution quadrupole time-of-flight mass spectrometry (HILIC/ESI-HR-QTOFMS). A comparison of the molecular-level compositional changes in IEPOX-SOA particles during aging with or without (*)OH revealed that decomposition of oligomers by heterogeneous (*)OH oxidation acts as a sink for (*)OH and maintains a reservoir of low-volatility compounds, including monomeric sulfate esters and oligomer fragments. We propose tentative structures and formation mechanisms for previously uncharacterized SOA constituents in PM(2.5). Our results suggest that this (*)OH-driven renewal of low-volatility products may extend the atmospheric lifetimes of particle-phase IEPOX-SOA by slowing the production of low-molecular weight, high-volatility organic fragments and likely contributes to the large quantities of 2-methyltetrols and methyltetrol sulfates reported in PM(2.5)" |
| Keywords: | *Sulfates/chemistry Atmosphere/chemistry Hemiterpenes Butadienes Aerosols/chemistry Particulate Matter/analysis Dust/analysis Oxidation-Reduction Oxidative Stress *Air Pollutants/analysis atmospheric lifetime atmospheric multiphase chemistry fragmentation; |
| Notes: | "MedlineArmstrong, N Cazimir Chen, Yuzhi Cui, Tianqu Zhang, Yue Christensen, Cade Zhang, Zhenfa Turpin, Barbara J Chan, Man Nin Gold, Avram Ault, Andrew P Surratt, Jason D eng CC/CDC HHS/ Research Support, N.I.H., Extramural Research Support, Non-U.S. Gov't Research Support, U.S. Gov't, Non-P.H.S. Research Support, U.S. Gov't, P.H.S. 2022/11/16 Environ Sci Technol. 2022 Dec 6; 56(23):16611-16620. doi: 10.1021/acs.est.2c03200. Epub 2022 Nov 15" |
