Research On Related Technologies Of Linear Ion Trap-Time Of Flight Mass Spectrometer

Atmospheric aerosols are widespread in the atmosphere and seriously affect the global climate and human health.As an important source of atmospheric aerosol,it is necessary to study the formation mechanism of New Particle Formation.The research on the formation mechanism is mainly carried out from the theoretical and experimental aspects.In terms of experiments,it is necessary to develop instruments for analyzing the composition and structural information of atmospheric clusters,and Infrared Photo-dissociation Spectrometer is one of them.It can be used to characterize the structural information of aerosol clusters,and then promote the research of formation mechanism of aerosols.However,the current Infrared Photo-dissociation Spectrometers have the problems of large volume and complicated structure due to their mass spectrometers,which are not conducive to the application of external field observation environment.In addition,the ionized products of atmospheric clusters are so complex that they are unconducive to the following spectral studies,and it is necessary to conduct a screening process before spectral analysis.Therefore,this thesis mainly focuses on mass spectrometer.Based on tandem mass spectrometry,a set of linear ion trap-time-of-flight mass spectrometer was designed and developed,which aims to ensure high storage efficiency and mass resolution,achieve the miniaturization of mass spectrometer,and implement the function of mass isolation.This mass spectrometer can be used as the core part of Infrared Photo-dissociation Spectrometer for the structural studies of atmospheric clusters.The main contributions are summarized as follows:1.In order to obtain the ion mass isolation function and strong ion storage capacity,some components of the linear ion trap mass spectrometer were designed and optimized,and the timing process and electrical parameters were optimized.Experiments were conducted on the main functions and performance indicators of the instrument.It is detected that the instrument has a mass resolution higher than 614 and an ion mass selective isolation function,and the isolation efficiency can reach 90%.2.In order to obtain higher mass resolution,the reflection time-of-flight mass spectrometer was optimized,and the DC high-voltage power supply and high-voltage pulse system were designed and produced to optimize the voltage parameters and timing signals of the time-of-flight mass spectrometer.Experiments were conducted on the mass resolution of the instrument,and the mass resolution of the instrument was higher than 2225.3.To achieve the design goal of miniaturization,a linear ion trap-time-of-flight mass spectrometry was formed based on tandem mass spectrometry technology,the timing of the tandem mass spectrometry was optimized,and performance testing and functional test experiments of the instrument were performed.Linear ion trap-time-of-flight tandem mass spectrometry can achieve mass analysis of the total ionized ion in the sample solution and mass isolation and analysis of the target ion,and the mass resolution of the target ion can reach 1940.The length of the instrument is 1.14 m,the width is 0.40 m,and the height is 1.28 m,which satisfies the design goal of miniaturization of the mass spectrometry part in the infrared light dissociation spectrometer.