Studying Ion Source Based On Electrospray Ionization Mass Spectrometry

Electrospray ion sources(ESI-MS)are considered to be one of the most potential ion sources for mass spectrometric analysis with the characteristics of multi charged ions and non fragmentation ions.In order to improve the electrospray ionization efficiency and ion transport efficiency,overcome by ion transport under atmospheric pressure electrospray mass spectrometry to produce in a high vacuum environment in the low transmission rate,vital developed stable and efficient ion source.Based on the principle of electrospray ionization mass spectrometry,a kind of ion focusing device,ion lens,is designed and produced in this dissertation.Under the guidance of the theory of flow field dynamics and electrodynamics,we can change the ion transmission efficiency by applying DC voltage and RF voltage on the ion lens.The main contents of this paper are as follows:Study on mechanism of producing gas phase ions by electrospray ion source.It is found that the ion transport efficiency of electrospray is the key factor limiting the performance of ion source.Therefore,a design scheme of ion lens is put forward to solve the problem of low transmission rate of electrospray ion source.The mathematical model of ion transmission under the ion lens and the analysis of the electric field in the ion lens are studied.The development of the ion lens and the construction of the electrospray experiment platform.The experimental platform was used to observe the droplet mode,droplet mode,cone jet mode and multiple jet mode produced by electrospray.By changing the voltage applied to the needle,the flow rate of the reserpine solution,the heating temperature of the capillary,the distance between the needle and the heating capillary,we study the performance of the ion lens.The ion lens is used in conjunction with the time of flight mass spectrometer,and the performance of the ion lens is detected by the mass spectrometric method.The test results show that the ion lens designed in this paper can increase the ion intensity by 4.9 times by mass spectrometry.