title: Characterization and quantification of isoprene-derived epoxydiols in ambient aerosol in the southeastern United States.
abstract: Isoprene-derived epoxydiols (IEPOX) are identified in ambient aerosol samples for the first time, together with other previously identified isoprene tracers (i.e., 2-methyltetrols, 2-methylglyceric acid, C(5)-alkenetriols, and organosulfate derivatives of 2-methyltetrols). Fine ambient aerosol collected in downtown Atlanta, GA and rural Yorkville, GA during the 2008 August Mini-Intensive Gas and Aerosol Study (AMIGAS) was analyzed using both gas chromatography/quadrupole mass spectrometry (GC/MS) and gas chromatography/time-of-flight mass spectrometry (GC/TOFMS) with prior trimethylsilylation. Mass concentrations of IEPOX ranged from approximately 1 to 24 ng m(-3) in the aerosol collected from the two sites. Detection of particle-phase IEPOX in the AMIGAS samples supports recent laboratory results that gas-phase IEPOX produced from the photooxidation of isoprene under low-NO(x) conditions is a key precursor of ambient isoprene secondary organic aerosol (SOA) formation. On average, the sum of the mass concentrations of IEPOX and the measured isoprene SOA tracers accounted for about 3% of the organic carbon, demonstrating the significance of isoprene oxidation to the formation of ambient aerosol in this region.
authors.affiliation: Division of Engineering and Applied Science, California Institute of Technology, Pasadena, California, USA.
authors.forename: Man Nin
authors.initials: MN
authors.lastname: Chan
authors.forename: Jason D
authors.initials: JD
authors.lastname: Surratt
authors.forename: Magda
authors.initials: M
authors.lastname: Claeys
authors.forename: Eric S
authors.initials: ES
authors.lastname: Edgerton
authors.forename: Roger L
authors.initials: RL
authors.lastname: Tanner
authors.forename: Stephanie L
authors.initials: SL
authors.lastname: Shaw
authors.forename: Mei
authors.initials: M
authors.lastname: Zheng
authors.forename: Eladio M
authors.initials: EM
authors.lastname: Knipping
authors.forename: Nathan C
authors.initials: NC
authors.lastname: Eddingsaas
authors.forename: Paul O
authors.initials: PO
authors.lastname: Wennberg
authors.forename: John H
authors.initials: JH
authors.lastname: Seinfeld
mesh_terms: D000336:Aerosols / Q000032:analysis* / Q000737:chemistry; D001272:Atmosphere / Q000737:chemistry; D002070:Butadienes / Q000032:analysis* / Q000737:chemistry; D004852:Epoxy Compounds / Q000032:analysis* / Q000737:chemistry; D008401:Gas Chromatography-Mass Spectrometry; D005740:Gases / Q000737:chemistry; D045782:Hemiterpenes / Q000032:analysis* / Q000737:chemistry; D052638:Particulate Matter / Q000032:analysis; D010420:Pentanes / Q000032:analysis* / Q000737:chemistry; D015144:Southeastern United States
chemical_list: D000336:Aerosols; D002070:Butadienes; D004852:Epoxy Compounds; D005740:Gases; D045782:Hemiterpenes; D052638:Particulate Matter; D010420:Pentanes; C005059:isoprene