title: Chemical Characterization of Secondary Organic Aerosol from Oxidation of Isoprene Hydroxyhydroperoxides.
abstract: Atmospheric oxidation of isoprene under low-NOx conditions leads to the formation of isoprene hydroxyhydroperoxides (ISOPOOH). Subsequent oxidation of ISOPOOH largely produces isoprene epoxydiols (IEPOX), which are known secondary organic aerosol (SOA) precursors. Although SOA from IEPOX has been previously examined, systematic studies of SOA characterization through a non-IEPOX route from 1,2-ISOPOOH oxidation are lacking. In the present work, SOA formation from the oxidation of authentic 1,2-ISOPOOH under low-NOx conditions was systematically examined with varying aerosol compositions and relative humidity. High yields of highly oxidized compounds, including multifunctional organosulfates (OSs) and hydroperoxides, were chemically characterized in both laboratory-generated SOA and fine aerosol samples collected from the southeastern U.S. IEPOX-derived SOA constituents were observed in all experiments, but their concentrations were only enhanced in the presence of acidified sulfate aerosol, consistent with prior work. High-resolution aerosol mass spectrometry (HR-AMS) reveals that 1,2-ISOPOOH-derived SOA formed through non-IEPOX routes exhibits a notable mass spectrum with a characteristic fragment ion at m/z 91. This laboratory-generated mass spectrum is strongly correlated with a factor recently resolved by positive matrix factorization (PMF) of aerosol mass spectrometer data collected in areas dominated by isoprene emissions, suggesting that the non-IEPOX pathway could contribute to ambient SOA measured in the Southeastern United States.
authors.affiliation: 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.
authors.forename: Matthieu
authors.initials: M
authors.lastname: Riva
authors.affiliation: 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.
authors.forename: Sri H
authors.initials: SH
authors.lastname: Budisulistiorini
authors.affiliation: 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.
authors.forename: Yuzhi
authors.initials: Y
authors.lastname: Chen
authors.affiliation: 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.
authors.forename: Zhenfa
authors.initials: Z
authors.lastname: Zhang
authors.affiliation: Department of Atmospheric Sciences, University of Washington , Seattle, Washington 98195 United States.
authors.forename: Emma L
authors.initials: EL
authors.lastname: D'Ambro
authors.affiliation: Center for Aerosol and Cloud Chemistry, Aerodyne Research , Billerica, Massachusetts 01821 United States.
authors.forename: Xuan
authors.initials: X
authors.lastname: Zhang
authors.affiliation: 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.
authors.forename: Avram
authors.initials: A
authors.lastname: Gold
authors.affiliation: 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.
authors.forename: Barbara J
authors.initials: BJ
authors.lastname: Turpin
authors.affiliation: Department of Atmospheric Sciences, University of Washington , Seattle, Washington 98195 United States.
authors.forename: Joel A
authors.initials: JA
authors.lastname: Thornton
authors.affiliation: Center for Aerosol and Cloud Chemistry, Aerodyne Research , Billerica, Massachusetts 01821 United States.
authors.forename: Manjula R
authors.initials: MR
authors.lastname: Canagaratna
authors.affiliation: 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.
authors.forename: Jason D
authors.initials: JD
authors.lastname: Surratt
mesh_terms: D000336:Aerosols; D001272:Atmosphere / Q000737:chemistry*; D013058:Mass Spectrometry; D010084:Oxidation-Reduction; D013431:Sulfates / Q000737:chemistry
chemical_list: D000336:Aerosols; D013431:Sulfates