Characterization and Quantification of Isoprene-Derived Epoxydiols in Ambient Aerosol in the Southeastern United States
Characterization and Quantification of Isoprene-Derived Epoxydiols in Ambient Aerosol in the Southeastern United States
复制标题
DOI：
10.1021/es100596b
复制
发表时间：
2010-06-15
影响因子：
11.4
通讯作者：
Seinfeld, John H.
中科院分区：
文献类型：
--
作者：
Chan, Man Nin;Surratt, Jason D.;Seinfeld, John H.
首次在环境气溶胶样品中鉴定出异戊二烯衍生的环氧二醇（IEPOX），以及其他先前鉴定的异戊二烯示踪剂（即，2-甲基四醇、2-甲基甘油酸、C-5-烯三醇和2-甲基四醇的有机硫酸酯衍生物）。在2008年8月小型密集气体和气溶胶研究（AMIGAS）期间，在佐治亚州亚特兰大市中心和佐治亚州约克维尔农村收集的精细环境气溶胶使用气相色谱/四极杆质谱（GC/MS）和气相色谱/飞行时间质谱（GC/TOFMS）进行了分析。从这两个地点收集的气溶胶中IEPOX的质量浓度范围从1到24 ng m（-3）。AMIGAS样品中颗粒相IEPOX的检测支持了最近的实验室结果，即在低NO条件下异戊二烯光氧化产生的气相IEPOX是环境异戊二烯二次有机气溶胶（SOA）形成的关键前体。平均而言，IEPOX和测得的异戊二烯SOA示踪剂的质量浓度之和约占有机碳的3%，表明异戊二烯氧化的环境气溶胶在该地区的形成的意义。
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 similar to 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, 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.