Primary and secondary contributions to ambient PM in the midwestern United States.
Primary and secondary contributions to ambient PM in the midwestern United States.
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DOI：
10.1021/es0720412
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发表时间：
2008-03
影响因子：
11.4
通讯作者：
M. Lewandowski;M. Jaoui;J. Offenberg;T. Kleindienst;E. Edney;R. Sheesley;J. Schauer
中科院分区：
文献类型：
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作者：
M. Lewandowski;M. Jaoui;J. Offenberg;T. Kleindienst;E. Edney;R. Sheesley;J. Schauer
2004 年在美国中西部的五个城市收集了环境 PM2.5 样本：伊利诺伊州东圣路易斯；密歇根州底特律；俄亥俄州辛辛那提；伊利诺伊州邦德维尔；和伊利诺伊州诺斯布鲁克。使用化学衍生化结合 GC-MS 分析来分析每月的复合材料，以估计几个来源对环境总有机碳的贡献。使用化学质量平衡（CMB）方法来估计几个主要来源的贡献。另一种基于有机示踪剂的技术被用来估计次生贡献，包括源自异戊二烯、α-蒎烯、β-石竹烯和甲苯的次生有机碳。将这些贡献的总和与每个采样点测得的总有机碳进行比较，并在五个采样点中的四个采样点观察到合理的碳质量平衡。在邦德维尔、诺斯布鲁克、辛辛那提和底特律，在估计的初级和次级贡献之和与测量的有机碳之间观察到很强的相关性（R2 = 0.73）。据观察，估计的次生有机碳浓度随季节变化很大，其中最强的贡献来自夏季的异戊二烯和α-蒎烯。虽然还需要进一步研究，但有一些证据表明，α-蒎烯、β-石竹烯和甲苯 SOC 的贡献估计可能在某种程度上代表了更广泛类别的单萜、倍半萜和芳香烃的贡献。
Ambient PM2.5 samples were collected in five midwestern United States cities throughout 2004: East St. Louis, Illinois; Detroit Michigan; Cincinnati, Ohio; Bondville, Illinois; and Northbrook, Illinois. Monthly composites were analyzed using chemical derivatization coupled with GC-MS analysis to estimate the contributions of several sources to the total ambient organic carbon. A chemical mass balance (CMB) approach was used to estimate contributions from several primary sources. An additional, organic tracer-based technique was employed to estimate secondary contributions, including secondary organic carbon derived from isoprene, alpha-pinene, beta-caryophyllene, and toluene. The sum of these contributions was compared with the total organic carbon measured at each sampling site, and reasonable carbon mass balances were observed for four of the five sites. In Bondville, Northbrook, Cincinnati, and Detroit a strong correlation was observed between the sum of the estimated primary and secondary contributions and the measured organic carbon (R2 = 0.73). The estimated secondary organic carbon concentrations were observed to vary considerably with season, with the strongest contributions coming from isoprene and alpha-pinene during the summer. While further research is required, there is some evidence that the contribution estimates for alpha-pinene, beta-caryophyllene, and toluene SOC may to some degree represent the contributions from the broader classes of monoterpenes, sesquiterpenes, and aromatics.