Research On Collision-induced Dissociation Technology Within Quadrupole-Linear Ion Trap Mass Spectrometry

Ion dissociation technology plays an important role in ion structure analysis and tandem mass spectrometry analysis.In the fields of proteomics and biochemistry involving the analysis of material structure,fragment ion information is obtained by in-trap ion dissociation technology,and the structure of precursor ion is deduced.With the new demand for mass spectrometry in biochemical analysis,researchers have developed a series of in-trap ion dissociation techniques,but there are still some problems to be solved urgently.Such as:(1)Low mass cut-off(LMCO);(2)the species of fragments are not rich enough;(3)the dissociation efficiency needs to be improved.To solve the above problems,a quadrupole-linear ion trap mass spectrometer is developed.Based on the principle of mass analyzer,the whole machine is designed.The simulation and mechanical design of pre-quadrupole-quadrupole mass analyzer are emphasized.After building a complete instrument platform,the performance indicators of the whole machine are tested:the mass scanning range of the instrument is 0-2000 amu,the resolution reaches unit resolution,and the correlation coefficient R~2=0.9995 in the linear regression equation.In order to improve the dissociation efficiency,a new type of ion dissociation technology is simulated by means of the combination of quadrupole and ion trap.The feasibility of the dissociation technology is verified by the simulation of mother ion trajectory before and during dissociation.Finally,a new collision-induced dissociation technology experiment is designed for quadrupole-linear ion trap platform.Through the influence of mass spectrometry parameters such as radio frequency voltage and gas pressure in the cavity on the dissociation efficiency of different samples,the rules and characteristics of the new collision-induced dissociation technology are summarized,and compared with the conventional collision-induced dissociation efficiency,better results are obtained.Finally,the new collision-induced dissociation technology is combined with conventional collision-induced dissociation technology to expand the instrument function and apply to clinical sample detection.