Development Of RF Quadrupole For GC/MS

Time-of-flight mass spectrometer(TOF-MS)is used in many fields such as food safety,environmental testing,disease control,and drug metabolism with high resolution,high sensitivity,and high accuracy of mass measurement.More and more important.The performance of TOF-MS has a huge relationship with ion guides.The ion guiding device of the foreign commercial TOF-MS instrument mainly adopts the structure of the electrostatic lens combined with the multi-pole collision chamber,and the instrument performance is excellent.Due to the limitation of the multi-pole technology,the electrostatic lens structure is usually only adopted in China,and the performance of the instrument is certain with foreign countries.difference.Therefore,researching a high-performance ion guide device similar to multipole technology is of great significance for improving the performance of domestic TOF-MS instruments.Based on the time-of-flight mass spectrometry platform developed by the team,this paper independently builds an ion guiding device based on RF quadrupole,which effectively improves the instrument performance and quality accuracy.The main contents are as follows:1.According to the hard ball collision model,Brownian motion model,RF field effective potential theory and quadrupole field space focusing theory,the mathematical model is established to realize the RF quadrupole design.2.Simulate the performance of the quadrupole by using the ion optical simulation program SIMION.Study the effects of different quadrupole voltages on the ion transmission efficiency of different masses,and guide the setting of the electrical parameters of the actual prototype.3.The designed quadrupole with a rod length of 7 cm,a rod diameter of 12 mm and a rod spacing of 10.46 mm was connected to the original TOF platform of the team to complete the prototype construction and perform performance tests.The test results show that the self-built instrument has good stability(RSD=1.3%),instrument resolution 7266(Full Width at Half Maximum,FWHM),mass range 27~966 amu,detection limit 1 pg octafluoronaphthalene(OFN),the dynamic range is up to four orders of magnitude,and the mass accuracy is less than 0.01 amu.Compared with the electrostatic transmission structure,the resolution of the instrument is increased from about 4,000 to more than 7,000,and the mass accuracy is improved from 0.05 amu to 0.01 amu.Long-term mass spectrometry experiments show that the self-built RF quadrupole ion guiding device can effectively improve the instrument performance of GC-TOF mass resolution and mass accuracy.The wide application of devices is of great significance for promoting the development of domestic mass spectrometry.