毛细管进样-激光解吸电离气溶胶飞行时间质谱仪检测超细纳米颗粒物化学成分  

Capillary Interface Laser Desorption Ionization Aerosol Time-of-Flight Mass Spectrometer Utilized to Measure Chemical Composition of Ultrafine Nanoparticles

作　　者：王涛 唐小锋 郭晓天 温作赢 顾学军 张为俊[1,3] WANG Tao;TANG Xiao-feng;GUO Xiao-tian;WEN Zuo-ying;GU Xue-jun;ZHANG Wei-jun(Anhui Institute of Optics and Fine Mechanics,Chinese Academy of Sciences,Hefei 230031,China;Institute of Material Science and Information Technology,Anhui University,Hefei 230031,China;School of Environmental Science and Optoelectronics Technology,University of Science and Technology of China,Hefei 230026,China)

机构地区：[1]中国科学院安徽光学精密机械研究所,安徽合肥230031 [2]安徽大学物质科学与信息技术研究院,安徽合肥230031 [3]中国科学技术大学环境科学与光电技术学院,安徽合肥230026

出　　处：《质谱学报》2020年第6期577-587,I0003,共12页Journal of Chinese Mass Spectrometry Society

基　　金：国家重点研发计划项目(2016YFC0200300);国家自然科学基金项目(91644109,21773249)资助。

摘　　要：采用毛细管大气压进样接口,结合激光多光子解吸、电离等技术,自行研制了毛细管进样-激光解吸电离气溶胶飞行时间质谱仪,用于在线测量超细纳米颗粒物的化学成分。应用商品化的气溶胶发生器和自制的离子诱导成核反应器,在实验室内分别产生了KCl、NaCl、NaI/NaBr混合物和Air/H 2O/SO 2混合气体成核反应的粒径小于100 nm的超细纳米颗粒物,并通过质谱仪获得了它们的化学成分信息。结果表明,相对于具有较大粒径的颗粒物,超细纳米颗粒物在激光多光子电离过程中更容易完全原子化电离,但通过改善激光的聚焦条件可以获得超细纳米颗粒物成分的分子信息。实验测量了毛细管大气压进样接口传输超细纳米颗粒物的效率,为0.33%,与国际同行采用类似大气压进样接口传输气体分子的效率一致。Ultrafine nanoparticles and new particle formation are significant components of aerosol particles in the air,which can influence the climate change and the quality of life in many ways.To get their chemical compositions is very important and helpful to reveal their sources and then make appropriate decisions to control their emissions efficiently.However,ultrafine nanoparticles are extremely small within nanometer size range,it is a technical challenge to probe their chemical compositions.More concretely,the traditional aerodynamic lens popularly utilized in a great deal of aerosol mass spectrometers is not suitable to transmit and focus ultrafine nanoparticles from air into mass spectrometer with a high vacuum,due to the Brownian movement.So up to now the related analytical instruments and the data of their chemical compositions are still very scarce.In this article,a home-made capillary interface laser desorption ionization aerosol time-of-flight mass spectrometer was presented to analyze on-line probe chemical composition of ultrafine nanoparticles with diameters of less than 100 nm in laboratory was presented.A silicon capillary with an inner diameter of 0.7 mm and a length of 18 cm were adopted as atmospheric interface to focus and transfer nanoparticles into the aerosol mass spectrometer.A 266 nm Nd:YAG laser combined with a tight focusing circular lens and a softly focusing cylindrical lens were employed to desorb and ionize nanoparticles,and then ions were detected by a linear time-of-flight mass analyzer.At the downstream of the particle beam and below the laser focusing spot,a faraday cup was installed in the aerosol mass spectrometer to collect and measure the current of the charged ultrafine nanoparticles.A commercial scanning mobility particle sizers(SMPS)was used to measure the size distribution and the total concentration of ultrafine nanoparticles on-line.As representative examples,ultrafine nanoparticles were produced from ion-induced nucleation reaction of Air/SO 2/H 2O mixture gases or spray o

关 键 词：超细纳米颗粒物 化学组分 毛细管进样接口 激光解吸电离 气溶胶飞行时间质谱仪 

分 类 号：O657.63[理学—分析化学]