AAAR 37th Annual Conference October 14 - October 18, 2019 Oregon Convention Center Portland, Oregon, USA
Abstract View
Autoxidation of Peroxy Radicals Formed from OH Radical-initiated Reactions of Trimethylbenzenes
Yuwei Wang, Archit Mehra, Jordan Krechmer, Andrew Lambe, Francesca Majluf, Douglas Worsnop, Manjula Canagaratna, Hugh Coe, LIN WANG, Fudan University
Abstract Number: 229 Working Group: Aerosol Chemistry
Abstract Secondary organic aerosols (SOAs) are formed in the atmosphere by oxidation of volatile gas-phase organic compounds, and have significant influence on human health and ecosystems. Highly oxygenated organic molecules (HOMs) are characterized with extremely-low volatility and thus are thought to be important precursors for SOA. However, traditional oxidation mechanisms initiated by OH radicals show a slow overall oxidation process, which don’t support the observed rapid formation of HOMs. In this study, we performed lab experiments to investigate the autoxidation of peroxy radicals produced from trimethylbenzenes, which are common anthropogenic aromatic emissions in urban environments. An OH-radical initiated, highly oxidizing environment that simulates atmospheric oxidation processes on timescales of days was achieved with a potential aerosol mass (PAM) oxidation flow reactor. A FIGAERO-Iodide-L-ToF-CIMS and a Vocus® PTR-MS were applied to measure the particulate products and gas-phase products, respectively. Strong evidence in favor of the extensive existence of autoxidation of aromatics were obtained.