Characteristics and sources of formic；acetic and oxalic acids in PM2.5 and PM10 aerosols in Beijing；China
Characteristics and sources of formic；acetic and oxalic acids in PM2.5 and PM10 aerosols in Beijing；China
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DOI：
10.1016/j.atmosres.2006.07.001
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发表时间：
2007-04
影响因子：
5.5
通讯作者：
Ying Wang;G. Zhuang;Shuang Chen;Z. An;A. Zheng
中科院分区：
文献类型：
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作者：
Ying Wang;G. Zhuang;Shuang Chen;Z. An;A. Zheng
从2002年3月至2003年10月，在北京市区和郊区的4个地点进行了甲酸、醋酸和草酸的化学研究。调查基于虚拟采样器采集的PM2.5和PM10气溶胶。这些羧酸在PM2.5和PM10中的总浓度分别为541ngm−3和615ngm−3，分别占气溶胶总质量的0.4%和0.3%。草酸是气溶胶中含量最丰富的羧酸。甲酸和醋酸表现出不同的季节变化(甲酸：春季；夏季；秋季；冬季；醋酸：春季和冬季；夏季和冬季；秋季和冬季)，城市不同地点的变化趋势是一致的。甲酸和草酸有昼夜变化。甲酸和醋酸在精细模式和粗模式中都有质量，而草酸在精细模式中占主导地位。这些酸的粗模组分在夏季升高。交通/灰尘/土壤/植被排放、煤炭/废物/生物质燃烧、烹饪和人为或天然气相前体的二次形成可能是这些酸的主要来源。用乙酸甲酸比(A/F)来区分原生源和次生源，结果表明农村原生源的贡献率高于城市。发展了一种新的方法来研究生物质燃烧对这些酸的贡献，估计气溶胶中的甲酸和草酸的贡献率为30-60%。
Chemistry of formic, acetic and oxalic acids was studied at four sites representing the urban and rural conditions in Beijing from March 2002 to October 2003. The investigation was based on the PM2.5and PM10aerosols collected with virtual samplers. The total concentrations of these carboxylic acids averaged at 541 ng m−3in PM2.5and 615 ng m−3in PM10, contributing 0.4% and 0.3% to the total mass of the aerosol, respectively. Oxalic acid was the most abundant carboxylic acids in aerosols. Formic and acetic acids displayed different seasonal variations (formic: spring<summer<autumn<winter; acetic: spring>summer>autumn>winter), and the variations of these acids were consistent among different sites in urban area. Formic and oxalic acids had a diurnal variation of nighttime<daytime. Formic and acetic acids had mass both in the fine and in the coarse modes, while oxalic acid predominated in the fine mode. The coarse mode fraction of these acids was elevated in summer. The traffic/dust/soil/vegetation emissions, coal/waste/biomass burnings, cooking and secondary formation from anthropogenic or natural gas-phase precursors could be the major sources of these acids. Acetic-to-formic acid ratio (A/F) was used to distinguish the primary sources and the secondary sources, and it indicated that the contribution of the primary sources was higher at rural site than at urban sites. A new method was developed to study the contribution of the biomass burning to these acids, which was estimated to be 30–60% for formic and oxalic acids in aerosols.