用于自由基化学反应研究的真空紫外光电离飞行时间质谱仪  

A Vacuum Ultraviolet Photoionization Time-of-Flight Mass Spectrometer for Investigation of Free Radical Reaction

作　　者：王涛 唐小锋 温作赢 张翠红 张为俊[2,3] WANG Tao;TANG Xiao-Feng;WEN Zuo-Ying;ZHANG Cui-Hong;ZHANG Wei-Jun(Institutes of Physical Science and Information Technology,Anhui University,Hefei 230601,China;Anhui Institute of Optics and Fine Mechanics,Chinese Academy of Sciences,Hefei 230026,China;School of Environmental Science and Optoelectronics Technology,University of Science and Technology of China,Hefei 230026,China)

机构地区：[1]安徽大学物质科学与信息技术研究院,合肥230601 [2]中国科学院安徽光学精密机械研究所,合肥230026 [3]中国科学技术大学环境科学与光电技术学院,合肥230026

出　　处：《分析化学》2020年第1期28-33,共6页Chinese Journal of Analytical Chemistry

基　　金：国家自然科学基金项目(Nos.21773249,91644109,91544228);中国科学院项目(No.116134KYSB20170048)资助~~

摘　　要：研制了真空紫外光电离飞行时间质谱仪,用于研究大气自由基化学反应。采用光子能量为10.6 eV的真空紫外放电灯作为电离源,利用新型笼式离子引出装置,实现了离子的高效率传输和聚焦。结果表明,仪器的检测灵敏度可达到0.03μg/L。结合微波放电流动管反应器模拟大气化学中的气相自由基反应,并通过自由基自反应动力学实现了CH 3浓度的定量分析。另外,利用真空紫外光电离飞行时间质谱仪,对CH 3+NO自由基反应的动力学进行了研究,检测了反应中的产物信息,测得其在室温和300 Pa压力下的反应速率常数为k(CH 3+NO)=1.2×100x0E䥺Symbolm@@0x0F12 cm 3/(molecule·s)。A home-made vacuum ultraviolet(VUV)photoionization time-of-flight mass spectrometer(VUVPI-TOFMS)was assembled to study atmospheric radical reactions.In the work,a commercial VUV discharge lamp with photon energy at 10.6 eV was installed as light source and a cage-shaped photoionization source was employed to efficiently extract and focus ions.With this spectrometer,a limit of detection(LOD)of 0.03μg/L(S/N=3)for benzene detection was obtained.Then a microwave discharge flow tube was employed as reactor to produce free radicals and model their atmospheric reactions.The concentration of the methyl radical was measured with its self-reaction kinetics within the flow tube.As a representative example,the reaction of CH 3 and NO was investigated by VUVPI-TOFMS.Both the stable species and radicals involved in the reaction were probed and the reaction rate constant at room temperature and 300 Pa pressure was measured to be k(CH 3+NO)=1.2×100x0E䥺Symbolm@@0x0F12 cm 3/(molecule·s).

关 键 词：飞行时间质谱仪 真空紫外光电离 流动管 自由基 

分 类 号：O65[理学—分析化学]