紧凑型高灵敏真空紫外单光子电离飞行时间质谱仪的研制及其在污染场地异味分析中的应用  

Development of a compact and highly sensitive vacuum ultraviolet single-photon-ionization time-of-flight mass spectrometer and its application in odorous analysis of a contaminated site

作　　者：郭烨东 于彰淇 姜葵 王海杰 杨波 束继年 李震 GUO Yedong;YU Zhangqi;JIANG Kui;WANG Haijie;YANG Bo;SHU Jinian;LI Zhen(National Engineering Laboratory for VOCs Pollution Control Material&Technology,University of Chinese Academy of Sciences,Beijing 101408,China)

机构地区：[1]中国科学院大学,挥发性有机物污染控制材料与技术国家工程实验室,北京101408

出　　处：《环境工程学报》2022年第9期3070-3080,F0002,共12页Chinese Journal of Environmental Engineering

基　　金：国家重点研发计划(2019YFC1806105);国家自然科学基金资助项目(22076184和21777170);中国科学院科研仪器装备研制项目(YJKYYQ20180072);中国科学院大学优秀教师科研能力提升项目(Y954021)。

摘　　要：真空紫外单光子电离质谱仪(SPI-MS)在挥发性有机物(VOCs)在线监测方面具有独特优势,然而目前常用的SPI-MS灵敏度普遍较低,限制了SPI-MS在环境监测领域的广泛应用。为了有效提高SPI-MS的检测灵敏度,达到实时在线监测环境中痕量VOCs的目的,采用自制的高通量真空紫外灯,结合低气压光电离技术和飞行时间质谱技术,研制了1台紧凑型高灵敏真空紫外单光子电离飞行时间质谱仪(SPI-TOFMS),并使用SPITOFMS和吹扫捕集气相色谱质谱(P&T GC-MS)标准方法对农药污染场地释放的异味气体进行了检测分析。结果表明:在10 s的检测时间内,该仪器对气态苯具有极高的检测灵敏度,检测限(以体积分数计)低至0.09×10^(−12),检测准确度为95%~109%,精确度的标准偏差小于8%;在农药场地异味气体分析中,SPI-TOFMS不仅在极短的检测时间内(10 s)检测到甲硫醇、二甲基硫和二甲基二硫等典型异味物质,还检测到更多未被P&T GC-MS标准方法检测到的异味物质,如吡咯烷、吡啶、乙基丙胺、苯胺、邻苯二胺和硝基苯等;SPI-TOFMS与P&T GCMS 2种方法对异味样品主要成分(二甲基二硫)的定量分析结果具有良好的一致性。本研究研制的紧凑型SPITOFMS与同类型仪器相比,检测灵敏度有了大幅提高,可为实验室模拟研究及外场环境中痕量VOCs的实时在线监测提供一种高效的技术方法。Vacuum ultraviolet single photon ionization mass spectrometer(SPI-MS)has unique advantages in on-line monitoring of volatile organic compounds(VOCs).However,the low sensitivity of the commonly used SPI-MS limits its wide application in environmental monitoring.In order to effectively improve the detection sensitivity of SPI-MS and realize the goal of real-time online monitoring of trace VOCs in the environment,a compact and highly sensitive vacuum ultraviolet single-photon-ionization time-of-flight mass spectrometer(SPITOFMS)was developed using a high-flux vacuum ultraviolet lamp combining with low-pressure photoionization technology and compact time-of-flight mass spectrometry.Then the SPI-TOFMS and purgeand-trap gas chromatography-mass spectrometry(P&T GC-MS)standard methods were used to analyze the gas phase samples of odorous substances released from the same pesticide site.The results show that the instrument exhibited an extremely high detection sensitivity toward gaseous benzene,the detection limit(in terms of volume ratio)was as low as 0.09×10^(−12) in 10 s acquisition time,the detection accuracy was 95%~109%with standard deviations less than 8%.In the analysis of odorous gas released from a pesticide site,the SPI-TOFMS could not only detect methanethiol,dimethyl sulfur,and dimethyl disulfide in a very short detection time(10 s),but also detect more odorous that cannot be detected by P&T GC-MS standard method,such as pyrrolidine,pyridine,ethyl propyl amine,aniline,o-phenylenediamine,and nitrobenzene.The SPI-TOFMS and P&T GCMS had a good agreement on the quantitative analysis results of the main component of the odor substances(dimethyl disulfide)in the odor samples.The compact SPI-TOFMS developed in this study has a much higher detection sensitivity compared with other analogue instruments,which can provide an efficient technical method for laboratory simulation and real-time online monitoring of trace VOCs in the field environment monitoring.

关 键 词：紫外单光子电离 挥发性有机物 在线监测 质谱 农药污染场地 异味 

分 类 号：X851[环境科学与工程—环境工程]