广州市夏季VOCs对臭氧及SOA生成潜势的研究

2016年7月在广州城区开展了27d的大气VOCs在线监测，共得到73种VOCs，总浓度均值为40.07×10^-9.其中烷烃占比55.17%，芳香烃占比15.42%，烯烃占比12.14%，氯代烃占比8.79%，乙炔占比3.97%，OVOC占比3.72%，乙腈占比0.79%.采用臭氧生成潜势（OFP）和OH自由基消耗速率估算了广州城区夏季VOC大气化学反应活性，结果表明芳香烃和烯烃是最主要的活性物种；VOCs的关键活性组分是甲苯、反-2-戊烯、间/对二甲苯、1，3-丁二烯、异戊二烯等.采用气溶胶生成系数法（FAC）估算了VOCs对二次有机气溶胶（SOA）的贡献，结果显示芳香烃、烷烃、烯烃分别占总SOA生成潜势量的95.54%、2.5%、1.95%，甲苯、间/对二甲苯、乙苯、邻二甲苯、1，2，4-三甲基苯是对SOA生成贡献最大的前5个物种.

Formation potential of ozone and secondary organic aerosol from VOCs oxidation in summer in Guangzhou,China

Online monitoring of atmospheric volatile organic compounds (VOCs) was performed at an urban site in Guangzhou for 27 days.A total of 73VOC species were detected with an average concentration of 40.07×10^-9 during the period,and the average proportions of alkane,aromatic,alkene,chlorinated hydrocarbon,acetylene,OVOC,acetonitrile were 55.17%,15.42%,12.14%,8.79%,3.97%,3.72%,0.79%,respectively.The ozone formation potential (OFP) and the OH radical loss rate were applied to assess chemical reactivity of VOCs.The results showed that aromatics and alkenes were the most active components in atmosphere,including toluene,trans-2-pentene,m/p-xylene,1,3-butadiene,isoprene,etc.Fractional aerosol coefficients (FAC) was used to estimate the potential formation of secondary organic aerosol (SOA).The results showed that aromatics,alkanes and alkenes,contributed 95.54%,2.5% and 1.95% to the total SOA formation potential,respectively.Toluene,m/p-xylene,ethylbenzene,o-xylene,1,2,4-trimethylbenzene were the top 5 largest contributors to SOA production.