铜离子对苯水相二次有机气溶胶化学组分和光学特性的影响研究  

Effects of copper ion on the chemical components and optical properties of benzene aqueous secondary organic aerosol

作　　者：王伟超 黄明强 朱敏聪 胡惠敏 蔡顺有 赵卫雄 胡长进 顾学军 张为俊[2] WANG Weichao;HUANG Mingqiang;ZHU Mincong;HU Huimin;CAI Shunyou;ZHAO Weixiong;HUChangjin;GU Xuejun;ZHANG Weijun(Fujian Provincial Key Laboratory of Modern Analytical Science and Separation Technology,College of Chemistry&Chemical Engineering and Environment,Minnan Normal University,Zhangzhou 363000;Laboratory of Atmospheric Physico-Chemistry,Anhui Institute of Optics and Fine Mechanics,Chinese Academy of Sciences,Hefei 230031)

机构地区：[1]闽南师范大学化学化工与环境学院,福建省现代分离分析科学与技术重点实验室,漳州363000 [2]中国科学院安徽光学精密机械研究所大气物理化学实验室,合肥230031

出　　处：《环境科学学报》2022年第7期140-147,共8页Acta Scientiae Circumstantiae

基　　金：国家自然科学基金(No.41575118);福建省自然科学基金(No.2020J02044,2021J01987)。

摘　　要：苯系物水相光氧化产生的二次有机气溶胶(SOA)能够散射、吸收太阳光辐射,导致大气能见度降低.铜离子是常见的重金属离子,它能改变水相SOA的化学组成和光学特性.本文采用自制的水相SOA产生装置,研究铜离子对苯水相SOA的组分和200~600 nm范围内平均质量吸收系数<MAC>的影响.结果表明,铜离子存在时,苯水相SOA的紫外谱图中275 nm处的酚类化合物吸收峰强度增大,激光解吸附电离质谱含有苯酚、苯二酚和苯三酚的特征离子峰m/z=93(C_(6_H_(5)O^(+))、m/z=109(C_(6)H_(5)O_(2)^(+))和m/z=125(C_(6)H_(5)O_(3)^(+)),电喷雾电离质谱出现质荷比高达1116的多聚物离子峰.这表明铜离子能够催化过氧化氢产生更多OH自由基,苯水相光氧化产生的苯酚、苯二酚、苯三酚等酚类化合物和由酚类聚合形成的羟基苯基醚多聚物含量增多.苯水相SOA的粒径和表征吸光能力的平均质量吸收系数<MAC>随着铜离子浓度的增大而逐渐增大.这为研究重金属离子存在背景下水相SOA的光学特性提供了实验依据.Secondary organic aerosol(SOA)formed from the aqueous photooxidation of aromatic compounds can scatter and absorb solar radiation,resulting in reduced atmospheric visibility.Copper ion is a common heavy metal ion,which can change the chemical components and optical properties of the aqueous SOA.The home-made generator apparatus of aqueous SOA was used to study the effects of copper ion on the composition and averaged mass absorption coefficient over 200~600 nm(<MAC>)of benzene aqueous SOA in this study.Experimental results shown that when copper ions were present,the absorption peak intensity of phenolic compounds at 275 nm in the UV spectrum of the benzene aqueous SOA increased,the laser desorption/ionization mass spectra contained characteristic ion peaks of phenol(m/z=93(C6H5O+)),dihydroxybenzene(m/z=109(C_(6)H_(5)O_(2)^(+)))and trihydroxybenzene(m/z=125(C_(6)H_(5)O_(3)^(+))),and the electrospray ionization mass spectra showed a polymer ion peak with a mass-to-charge ratio as high as 1116.These results indicated that copper ion can catalyze hydrogen peroxide to produce more OH radicals,and the content of phenolic compounds,such as phenol,dihydroxybenzene,trihydroxybenzene and hydroxyphenyl ether polymer formed by polymerization of phenol in aqueous photooxidation of benzene was increased.The particle size of benzene aqueous SOA and the averaged mass absorption coefficient<MAC>,which characterized the light absorption capacity,gradually increased with the increasing concentration of copper ion.These provided the experimental basis for studying the optical properties of aqueous SOA in the presence of heavy metal ions.

关 键 词：苯 铜离子 水相反应 二次有机气溶胶(SOA) 光学特性 

分 类 号：X51[环境科学与工程—环境工程] X131.1