大气挥发性有机物实时在线监测的双极性质子转移反应质谱仪研制  

Development of Dipolar Proton Transfer Reaction Mass Spectrometer for Real-time Monitoring of Volatile Organic Compounds in Ambient Air

作　　者：张强领 邹雪[1] 梁渠 张亚婷 易明建[4] 王鸿梅 黄超群[1] 沈成银[1] 储焰南[1] ZHANG Qiang-Ling;ZOU Xue;LIANG Qu;ZHANG Ya-Ting;YI Ming-Jian;WANG Hong-Mei;HUANG Chao-Qun;SHEN Cheng-Yin;CHU Yan-Nan(Anhui Province Key Laboratory of Medical Physics and Technology,Center of Medical Physics and Technology,Hefei Institutes of Physical Science,Chinese Academy of Sciences,Hefei 230031,China;University of Science and Technology of China,Hefei 230026,China;Anhui Institute of Optics and Fine Mechanics,Chinese Academy of Sciences,Hefei 230031,China;Institute of Atmospheric Environment,Research Academy of Environmental Sciences of Anhui Province,Hefei 230026,China)

机构地区：[1]中国科学院合肥物质科学研究院,医学物理与技术中心,医学物理与技术安徽省重点实验室,合肥230031 [2]中国科学技术大学,合肥230026 [3]中国科学院安徽光学精密机械研究所,合肥230031 [4]安徽省环境科学研究院大气环境研究所,合肥230026

出　　处：《分析化学》2018年第4期471-478,共8页Chinese Journal of Analytical Chemistry

基　　金：本文系国家重点研发计划项目(No.2016YFC0200200)、国家自然科学基金项目(Nos.21777163,21477132,21577145)和国家科技支撑计划项目(No.2014BAC22B06)资助。

摘　　要：大气中挥发性有机物(VOCs)能参与光化学反应,导致臭氧和气溶胶等二次污染物的产生,实时精准地监测VOCs对于大气污染成因研究具有重要意义。在质子转移反应质谱(PTR-MS)研究基础上,本工作研制一套用于大气VOCs实时在线监测的双极性质子转移反应质谱仪(Dipolar proton transfer reaction mass spectrometer,DP-PTR-MS)。相比单一反应离子H_3O^+的常规PTR-MS,DP-PTR-MS中有正负3种反应离子(H_3O^+、OH^-、(CH_3)_2COH^+),可根据实际检测需要选择切换,提高定性能力,并有效扩展检测范围。其中,H_3O^+反应离子用于检测质子亲和势大于H_2O的VOCs;OH^-反应离子可与H_3O^+反应离子配合识别VOCs,还可用于检测CO_2等无机物;(CH_3)_2COH^+反应离子可在排除干扰的情况下准确检测NH_3。利用6种标准气体测定DP-PTR-MS检出限和灵敏度,结果表明,DP-PTR-MS对甲苯的检出限为7×10^(-12)(V/V),对氨气的灵敏度为126.0 cps/10^(-9)(V/V)。利用DP-PTR-MS对合肥市区大气VOCs开展连续78h实时在线监测验证实验,结果表明,DP-PTR-MS可对大气中10^(-12)(V/V)量级VOCs进行长期实时在线监测,可作为大气污染成因研究和痕量VOCs排放监测的重要工具。Volatile organic compounds(VOCs)in ambient air can participate in photochemical reactions,which lead to the generation of secondary pollutants such as ozone and aerosol.So real-time and accurate monitoring of atmospheric VOCs plays an important role in the study of the causes of air pollution.On the basis of proton transfer reaction mass spectrometry(PTR-MS)research,a novel dipolar proton transfer reaction mass spectrometer(DP-PTR-MS)for real-time and on-line monitoring atmospheric VOCs was developed.Compared with the conventional PTR-MS with one kind of reagent ion H 3O+,DP-PTR-MS had three kinds of reagent ions H 3O+,OH-,(CH)2COH+,which could be switched according to the actual detection need.So DP-PTR-MS can improve the qualitative ability and expand the detection range effectively.The reagent ion H 3O+can be used for detecting VOCs whose proton affinities are greater than that of H 2O.The reagent ion OH-can be used to identify VOCs cooperating with the reagent ion H 3O+,and can also be used for detecting some inorganic substances such as CO 2.The reagent ion(CH 3)2COH+can be used for accurately detecting NH 3 under interference elimination circumstances.The limit of detection(LOD)and sensitivity of DP-PTR-MS were measured by using six kinds of standard gases.The results showed that the LOD for detecting toluene was 7×10-12(V/V)and the sensitivity for detecting ammonia has reached 126 cps/10-9(V/V).The ambient air in Hefei city was on-line and real-time monitored for continuous 78 hours with DP-PTR-MS.The results showed that the newly developed DP-PTR-MS could be used for long-term and real-time monitoring atmospheric VOCs with the concentration of 10-12(V/V)level.DP-PTR-MS is an important tool for the study of the causes of atmospheric pollution and the monitoring of trace VOCs emissions.

关 键 词：双极性质子转移反应质谱 挥发性有机物 实时 在线监测 

分 类 号：TH843[机械工程—仪器科学与技术]