摘要
为了实现低真空环境下质谱仪的质量分析,提出了利用Langevin碰撞理论模拟低真空环境下离子运动轨迹的方法,该方法可以更准确地反映离子的运动状态。针对四极杆质量分析器,在COMSOL Multiphysics中搭建了适用于低真空环境的离子运动仿真平台。利用该平台仿真得到了低真空条件下,背景气体压强、离子质荷比、背景气体质量、离子初始能量、四极杆半径以及温度对四极杆质谱仪灵敏度的影响。仿真结果表明,随着压强升高,质谱仪灵敏度降低,通过改变离子操作模式,可以削弱由压强变化引起的灵敏度降低,这为低真空质谱仪的设计提供参考。
There are many chemical measurement scenarios that benefit from hand portable mass spectrometer.However,the vacuum system requirement has been the primary challenge in reducing the size and weight.If mass analysis is arranged at low vacuum condition,the bulky turbo pump can be eliminated which will minimize size,weight and power of portable MS.In order to acquire the ion operation mode suiting for low vacuum mass spectrometer,aiming at QMF,we set up a simulation platform in COMSOL Multiphysics based on Langevin collision model which was superior to the damping force model used before.By using this platform,six parameters were evaluated which may affect the sensitivity of the quadrupole MS.The parameters were consist of the pressure of the buffer gas,the mass to charge of ions,the mass of background gas,the initial velocity of the ions,the radius of the quadrupole and the temperature.The Langevin collision model simulation results showed that three states of ions in low vacuum quadrupole could be acquired which formed a sharp contract to the two states by applying the damping force model.This means that the results acquired by Langevin collision model accords better to the reality.At low vacuum condition,the increasing of collisions between ions and background gas molecule decreased the sensitivity of MS.Nevertheless,according to the simulation results,increasing the initial kinetic energy of ions,enlarging the radius of quadruple rods,raising the temperature and using the small mass background gas would contribute to a higher sensitivity at low vacuum condition.Besides,ions with greater mass were easier to get a higher sensitivity.It can be concluded that by using a proper ion operation mode,the decreasing sensitivity caused by pressure will regain.This provides a guidance for the design of low vacuum MS which can significantly reduce the pumping requirements required for miniature MS.The next work is to design an actual quadrupole MS instrument according to the results of the simulation and to evaluate the enhancement of sensitivity.
作者
姜佩贺
周志权
陈焕文
赵占锋
JIANG Peihe;ZHOU Zhiquan;CHEN Huanwen;ZHAO Zhanfeng(School of Electronics and Information Engineering, Harbin Institute of Technology,Harbin150001,China;School of Information and Electrical Engineering,Harbin Institute of Technology at Weihai,Weihai264209,China;Jiangxi Key Laboratory for Mass Spectrometry and Instrumentation Chemistry,East China University of Technology,Nanchang330013,China)
出处
《质谱学报》
EI
CAS
CSCD
北大核心
2018年第1期20-27,共8页
Journal of Chinese Mass Spectrometry Society
基金
国家自然科学基金青年基金(21505028)
山东省自然科学基金(ZR2015BQ004)资助
作者简介
姜佩贺(1988—),男,吉林通化人,博士研究生,信息与通信工程专业。E mail: jiangpeihe@163.com;通信作者:赵占锋(1980—),男,河北辛集人,副教授,从事质谱仪器研究。E mail: zhaozhanfeng@hitwh.edu.cn
