Chemical Characterization of Secondary Organic Aerosol from Oxidation of Isoprene Hydroxyhydroperoxides

• DOI: 10.1021/acs.est.6b02511
• Publication Date: 2016-07-28T19:39:18Z
• Authors: Matthieu Riva; Sri H. Budisulist...; Yuzhi Chen; Zhenfa Zhang; Emma L. D’Ambro; Xuan Zhang; Avram Gold; Barbara J. Turpin; Joel A. Thornton; Manjula R. Canaga...; Jason D. Surratt
• Keywords: Isoprene

Atmospheric oxidation of isoprene under low-NOx conditions leads to the formation hydroxyhydroperoxides (ISOPOOH). Subsequent ISOPOOH largely produces epoxydiols (IEPOX), which are known secondary organic aerosol (SOA) precursors. Although SOA from IEPOX has been previously examined, systematic studies characterization through a non-IEPOX route 1,2-ISOPOOH lacking. In present work, authentic was systematically examined with varying compositions and relative humidity. High yields highly oxidized compounds, including multifunctional organosulfates (OSs) hydroperoxides, were chemically characterized in both laboratory-generated fine samples collected southeastern U.S. IEPOX-derived constituents observed all experiments, but their concentrations only enhanced presence acidified sulfate aerosol, consistent prior work. High-resolution mass spectrometry (HR-AMS) reveals that 1,2-ISOPOOH-derived formed routes exhibits notable spectrum characteristic fragment ion at m/z 91. This is strongly correlated factor recently resolved by positive matrix factorization (PMF) spectrometer data areas dominated emissions, suggesting pathway could contribute ambient measured Southeastern United States.