Research On Key Technologies Of Portable Gas Chromatography Mass Spectrometer

Gas chromatography-mass spectrometry(GC-MS)is one of the commonly used analytical methods in the laboratory,owing to its highly accurate qualitative and quantitative.GC-MS has been reported in a large area of applications,including environmental monitoring,petrochemical,food safety.However,the application of traditional gas chromatograph mass spectrometer is limited in laboratory analysis,because of its large volume,high energy consumption and strict operating environment.Portable gas chromatography mass spectrometer is becoming a favorable alternative,because it has the advantages of small volume,low power consumption,and fast analysis.The application of portable GC-MS has been well documented,for environmental monitoring,emergency response,fire accident investigation,chemical warfare agent,and rapid detection of toxic industrial chemicals.However,the development of the portable GS-MS technique in China is relatively weak and,thus,the imported instruments,such as HAPSITE,TRIDIO N,completely occupies the market.Therefore,to address the increasing market demand and improve the development level of mass spectrometer in China,it is important to develop a portable gas chromatograph mass spectrometer.In this study,a portable gas chromatograph mass spectrometer was developed for field analysis.It features small size and low power consumption,and has the further benefit of rapid analysis.Firstly,we modularized the chromatographic part of the portable gas chromatography mass spectrometer.The gasification chamber,the column and the mass spectrum vacuum chamber were integrated in the structure,and the coordinating interface and heating control device were designed.For the software,the temperature control system is integrated into the portable gas chromatography mass spectrometer software system to realize the precise temperature control of the gasification chamber and the column.In this sense,the temperature measurement curve is corrected.Moreover,the capability for analytes separation and the stability for analysis were evaluated.Then,we systematically investigated the factors that influence the performance of the mass spectrometer.The mass analyzer used in this work was a self-designed hybrid ion trap.It was designed according to the simulation results regarding the ion trap.The inter-electrode insulation was optimized and therefore avoiding the discharge between the electrodes.The RF signal power amplifier modules including RF power amplifier and RF booster were designed.A weak signal amplification and detection module is developed for the detection of the current.The vacuum chamber,vacuum gauge,and vacuum pump were integrated as a small vacuum system,and the performance of this system was investigated,which could reached the requirement of ion trap vacuum within 10 min.Finally,we integrated the gas chromatography and mass spectrometry,resulting in the formation of portable GC-MS.The assembly of each module was optimized using Solidworks software,which determined the relative position of the modules.The installation of the circuit system was investigated and the stacking structure was the optimization.After integration and installation of the portable GC-MS,the performance of this instrument was systematically investigated,and the preliminary results were satisfactory and provided valuable information for further filed analysis.