单电极介质阻挡放电离子源研究  

Study of Single Electrode Dielectric Barrier Discharge Ion Source

作　　者：宁录胜 徐明[1] 郭成安[2] 赵鹏[1] 闻路红[1] 张新荣[2] 

机构地区：[1]宁波大学高等技术研究院,宁波315211 [2]清华大学化学系,北京100084

出　　处：《分析化学》2016年第2期252-257,共6页Chinese Journal of Analytical Chemistry

基　　金：宁波大学学校人才工程项目(No.ZX2014000824);宁波大学王宽诚幸福基金资助项目;宁波市自然科学基金(No.2014A610158)

摘　　要：介质阻挡放电离子源是一种常压敞开式离子源,由于免试剂、适用范围广、易于小型化等特点而备受关注。该类离子源多采用表面双电极或针-环电极设计方式。表面双电极的接地电极会减弱氦气在强电场中电离形成的流注崩头能量,缩短等离子束喷射距离。针-环电极的电场主要集中在针电极尖端,流注崩头能量小,等离子束喷射距离比表面双电极还短。本研究对放电影响因素进行分析,通过改变电极形状和增加绝缘介质部件进行电场调整,使强电场区域集中于电极一侧,解决了单电极回流放电问题,从而获得稳定、高效的等离子束,其最大长度可达8 cm以上。基于电场调整技术,研制出单电极介质阻挡放电离子源,它主要由惰性载气、高压电极、绝缘介质管、气控以及温控部分组成。使用新型离子源对咖啡因液态样品和扑热息痛固体药片进行了质谱分析,前者的定量曲线R^2值为99.66%,100μg/L的信噪比为23;后者的主要成分对乙酰氨基酚可在质谱中快速检出,响应强度为1.26×(10)~6。上述结果表明,新型离子源可以实现样品的定量和快速原位分析。Dielectric barrier discharge ion source is an ambient ion source. Coupled with its advantages of solvent-free method, extensive application scope and easy miniaturization, it has attracted widespread attention. The conventional dielectric barrier discharge ion source uses surface double electrode or needle-ring electrode designs. The grounded electrode of the former can weaken ionization head energy formed in strong electric field of helium ionization, and shorten the distance of plasma beam. The electric field of the latter mainly concentrates on the peak of the needle electrode, which can weaken the energy of ionization head and make the length of the plasma beam shorter than the surface double electrode. In this work, the influencing factors of discharge were analyzed, and the electric field was adjusted by changing the shape of the electrode and increasing insulation medium components, thus forcing the strong electric field to focus on one side of the electrode, which could avoid the reflux discharge phenomenon and achieve stable and efficient plasma beam. The maximum length of plasma beam could reach more than 8 cm. On the basis, a single electrode dielectric barrier discharge ion source （DBDI）, mainly composed of inert carrier gas, high voltage electrode, insulation tube, gas control and temperature control parts, was developed. Using the new type of ion source, the liquid sample of caffeine and the solid tablets of acetaminophen were analyzed by DBDI-MS. The correlation coefficient of the caffeine quantitative curve was 99.66%, and the signal to noise ratio of 100 μg/L was 23. The main component of the acetaminophen was CsH9NO2 that could be rapidly detected in the mass spectrum, and the response intensity was 1.26×106. The results showed that the new type of ion source could realize the quantitative and rapid in situ analysis of the sample.

关 键 词：单电极 介质阻挡放电 离子源 

分 类 号：O657.63[理学—分析化学]