Relative contributions of selected multigeneration products to chamber SOA formed from photooxidation of a range (C 10 -C 17 ) of n -alkanes under high NO x conditions

• Published in: Atmospheric environment (1994) 2021-01, Vol.244 (1)
• Main Authors: Docherty, Kenneth S, Yaga, Robert, Preston, William, Jaoui, Mohammed, Reidel, Theran P, Offenberg, John H, Kleindienst, Tadeusz E, Lewandowski, Michael
• Format: Article
• Language: English
• ISSN: 1352-2310
• DOI: 10.1016/j.atmosenv.2020.117976

A series of chamber experiments was conducted to investigate the composition of secondary organic aerosol (SOA) following oxidation of a range of parent -alkanes (C -C ) in the presence of NO . The relative contribution of selected species representing first, second, and higher generation products to SOA mass was measured using a high-resolution aerosol mass spectrometer. Gas chromatography was also used for a limited set of amenable species. Relative contributions varied substantially across the range of investigated alkanes reflecting slight changes in SOA composition. The contribution of first-generation cyclic hemiacetal is minimal toward the small end of the investigated range and gradually increase with -alkane size. The relative contribution of second generation and higher nitrate-containing species, in contrast, decrease with an increased alkane size. A similar trend is observed for relative contribution of organonitrates to SOA. Finally, SOA yield and composition are sensitive to water vapor concentrations. This sensitivity is limited to a narrow range (dry to ~15% RH) with little, if any, impact above 15% suggesting that this impact may be negligible under ambient conditions. The impact of water vapor also appears to decrease with increasing alkane carbon number.