同步辐射真空紫外光电离气溶胶质谱在线检测苯乙烯二次有机气溶胶  

On-line Measurement of Styrene Secondary Organic Aerosol Using Synchrotron Radiation Vacuum Ultraviolet Photoionization Aerosol Mass Spectrometer

作　　者：黄明强 单晓斌[2] 盛六四[2] 王振亚[3] 胡长进[3] 顾学军 张为俊 HUANG Ming-Qiang;SHAN Xiao-Bin;SHENG Liu-Si;WANG Zhen-Ya;HU Chang-Jin;GU Xue-Jun;ZHANG Wei-Jun(Fujian Province Key Laboratory of Modern Analytical Science and Separation Technology,College of Chemistry&Chemical Engineering and Environment,Minnan Normal University,Zhangzhou 363000,China;National Synchrotron Radiation Laboratory,University of Science and Technology of China,Hefei 230029,China;Laboratory of Atmospheric Physico-Chemistry,Anhui Institute of Optics and Fine Mechanics,Chinese Academy of Sciences,Hefei 230031,China)

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]中国科学技术大学,国家同步辐射实验室,合肥230029 [3]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：《分析化学》2024年第8期1200-1210,共11页Chinese Journal of Analytical Chemistry

基　　金：国家自然科学基金项目(Nos.42275136,41575118);福建省自然科学基金项目(Nos.2021J01987,2020J02044)资助。

摘　　要：苯乙烯等芳香烃光氧化产生的二次有机气溶胶(SOA)是城市大气细粒子的主要组成部分。前期研究采用离线方法测量SOA的组分和含量,但离线检测程序复杂,检测时间长,并可能带来二次污染。本研究利用同步辐射真空紫外光电离气溶胶质谱(VUV-PIAMS)在线测量烟雾箱模拟产生的苯乙烯SOA的化学组分和含量。利用10.5 eV同步辐射光子测量SOA粒子的光电离质谱,基于各离子峰的峰面积定量分析主要组分的占比;在7.5~11.5 eV同步辐射光子范围内获得各离子峰的光电离效率曲线,进而得到电离势定性分析组分结构。结果显示,苯乙烯SOA的光电离质谱图主要含有m/z 106、108、120和122离子峰,各质谱峰的电离势分别为(9.41±0.03)eV、(8.93±0.03)eV、(9.24±0.03)eV和(9.25±0.03)eV。结合量子化学计算、红外吸收光谱和电喷雾电离质谱离线测量验证,测得苯甲醛、苯甲醇、4-乙烯基苯酚和苯甲酸是苯乙烯SOA的主要组分,分别占测量组分的32.5%、17.5%、25%和15%,生成的量比为13∶7∶10∶6。本研究结果表明,VUV-PIAMS能够克服离线检测存在的不足,可用于SOA组分和含量的在线检测,是测量SOA粒子化学成分和揭示其形成过程的有力工具。Secondary organic aerosol(SOA)produced by photooxidation of styrene and other aromatic compounds is a major part of fine particles in urban atmosphere.In this study,the measurement of component and content of SOA formed from photooxidation of styrene in smog chamber using synchronous radiation vacuum-ultraviolet photoionization aerosol mass spectrometer(VUV-PIAMS)was conducted.Photoionization mass spectra of styrene SOA was detected by synchrotron radiation photon with 10.5 eV,and the proportion of main components was quantified based on the peak area of each ion peak.The photoionization efficiency curve of ion peak was obtained under synchrotron radiation photons in the range from 7.5 to 11.5 eV,and then the ionization potential was acquired for qualitative analysis of the component structure.The results showed that the photoionization mass spectra of styrene SOA mainly contained ion peaks at m/z 106,108,120 and 122,and the ionization potentials of each peak were(9.41±0.03)eV,(8.93±0.03)eV,(9.24±0.03)eV and(9.25±0.03)eV,respectively.Combined with quantum chemistry calculation and off-line measurement verification of infrared absorption spectra and electrospray ionization mass spectra,it was determined that benzaldehyde,benzyl alcohol,4-vinylphenol and benzoic acid were main components of styrene SOA,accounting for 32.5%,17.5%,25%and 15%of the measured components,respectively,and the generated quantity ratio was 13∶7∶10∶6.VUV-PIAMS could overcome the disadvantages of off-line method,and could on-line detect component and content of SOA,proving a useful tool to measure the chemical components and reveal the formation process of SOA particles.

关 键 词：同步辐射 光电离气溶胶质谱 苯乙烯 二次有机气溶胶 反应机理 

分 类 号：O657.63[理学—分析化学] X831[理学—化学]