Characterization and quantification of isoprene-derived epoxydiols in ambient aerosol in the southeastern United States.
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.
Chan
Man Nin
MN
Division of Engineering and Applied Science, California Institute of Technology, Pasadena, California, USA.
Surratt
Jason D
JD
Claeys
Magda
M
Edgerton
Eric S
ES
Tanner
Roger L
RL
Shaw
Stephanie L
SL
Zheng
Mei
M
Knipping
Eladio M
EM
Eddingsaas
Nathan C
NC
Wennberg
Paul O
PO
Seinfeld
John H
JH
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
D000336:Aerosols; D002070:Butadienes; D004852:Epoxy Compounds; D005740:Gases; D045782:Hemiterpenes; D052638:Particulate Matter; D010420:Pentanes; C005059:isoprene