电子轰击电离源-离子阱质谱的质量范围优化程序研究  

Optimization Procedure of Mass Range for Electron Impact Ion Source Ion Trap Mass Spectrometry

作　　者：王伟民 靳留雨 钱炳君 徐福兴 丁传凡 WANG Wei-Min;JIN Liu-Yu;QIAN Bing-Jun;XU Fu-Xing;DING Chuan-Fan(Key Laboratory of Advanced Mass Spectrometry and Molecular Analysis of Zhejiang Province,Institute of Mass Spectrometry,School of Materials Science&Chemical Engineering,Ningbo University,Ningbo 315211,China)

机构地区：[1]宁波大学材料科学与化学工程学院,浙江省先进质谱技术与分子检测重点实验室,质谱技术与应用研究院,宁波315211

出　　处：《分析化学》2022年第2期198-205,共8页Chinese Journal of Analytical Chemistry

基　　金：国家自然科学基金项目(Nos.21803013,21927805);中国科学院大连化学物理研究所基金项目(No.DICP ZZBS201701,DICP I201951)资助。

摘　　要：电子轰击电离源(Electron impact ion source,EI)是一种真空中使用的高效电离源,其电离效率可达到0.1%,几乎可以电离所有的物质。近年来,电子轰击电离源-离子阱质谱(EI-ion trap mass spectrometry,EI-ITMS)的发展使得便携式气相色谱-质谱联用仪广泛应用于有毒有害物质的快速现场定性和定量检测。然而,EI-ITMS仪器的性能调试十分繁琐。首先,EI的离子传输效率需要设置合适的透镜电压提取系统,其次,EI电离会产生大量的碎片离子,为了保证最佳的质量范围,需要对离子阱质量分析器的相关电压参数不断进行微调。鉴于此,本研究基于自主研制的电子轰击离子源-离子阱质谱仪,建立了EI-ITMS的质量范围优化调试程序。所研制的EI电离源和离子阱质量分析器在轴向上串联,气体样品通过内径75μm的石英毛细管进入EI源后,产生的离子在提取电极系统的作用下加速、聚焦,再流向离子阱质量分析器,离子阱的前端盖电压作为门控,控制离子进入。对电子轰击源的各项参数进行了优化,并利用Simion软件模拟研究了实验条件下离子的运动轨迹和传输效率。所建立的EI-ITMS质量范围优化程序有助于缓解离子阱质量分析器的质量歧视效应,实现EI电离产生的小质量碎片分析。实验结果表明,利用所建立的程序可以实现丙酮的碎片离子m/z 43和全氟三丁胺的碎片离子m/z 414的检测。Electron impact ion source(EI)is a kind of highly efficient ionization source that can be used in vacuum.The ionization efficiency of EI can reach 0.1%,and EI can ionize almost all substances.In recent years,the development of electron impact ion source-ion trap mass spectrometry(EI-ITMS)has made great progress,which makes portable gas chromatograph-mass spectrometer(GC-MS)widely used in the rapid qualitative and quantitative detection of toxic and harmful substances.However,the performance debugging of EI-ITMS instrument is still very complicated.Firstly,the ion transmission efficiency of EI needs to set up a suitable lens voltage.Secondly,EI ionization will produce a large number of fragmented ions.To ensure the best mass range,it is necessary to continuously fine tune the relevant voltage parameters of the ion trap mass analyzer.In this work,a set of mass range optimization debugging program was established on the basis of homemade EI-ITMS devices.The developed EI-ITMS were connected in the axial direction.The gas sample entered the EI source through a 75-μm quartz capillary tube,and then the generated ions were accelerated and focused under the action of the extraction electrode system and flowed to the ion trap.The frontcap voltage of the ion trap was used as the gate to control the entry of ions.The parameters of the EI were optimized,and the motion trajectory and transmission efficiency of the ions under the experimental conditions were simulated using simion software.The established mass range optimization program was helpful to alleviate the mass discrimination effect of ion trap mass analyzer and realized the analysis of small mass fragments produced by EI ionization.Experiments showed that the established program could successfully optimize the detection of acetone fragment ion m/z 43 and perfluorotributylamine fragment ion m/z 414.This work laid a foundation for the introduction of chromatographic analysis.

关 键 词：电子轰击电离源 Simion软件 离子捕获效率 离子阱质量截止 

分 类 号：O657.63[理学—分析化学]