The Study On The Mechanism And Quantity Of Fast Atom Bombardment Mass Spectrometry

We study on the mechanism and quantity of fast atom bombardment mass spectrometry in this paper. We prove that the mechanism of FABMS, by the mass chromatography of salts and polarity molecule, are explained as a result of desorption of ions already present on the surface or as a result of ion-molecule reactions occurring during the desorption . We determined of K+ and hyantoin quantitatively by fast atom bombardment mass spectrometry. We study all kinds of the factors'effect. We determine the ion-molecule of tryptophan under different additives and matrices and find out the optimal conditions. This paper consists of four chapters. Chapter one: The reviews of fast atom bombardment mass spectrometry Fast atom bombardment, a new soft ionization technique for mass spectrometry, is briefly reviews. We introduce the process of produce and development of FAB, the ionization mechanism of it, the effect of the matrix and the additive used in FAB and its application on the quantitative analysis. Chapter two: Determine the hyantoin using the fast atom bombardment mass spectrometry We determine the quasi-ion molecule mass chromatography of different substitution hyantoin at C5,5. We found the rule of exponential decrease of the quasi-ion molecule by the non-liner curve fitting of them. The ratio of intensity of 5,5-dimethyl-hyantoin and 5-methyl-5-ethyl-hyantoin is linear with the concentration of the 5,5-dimethyl-hyantoin. We determine the 5,5-dimethyl-hyantoin quantitatively using the 5-methyl-5-ethyl-hyantoin as the internal standard. The standard equation is y=-0.0204+0.154x(R=0.99206), the range is 1-25g/L, RSD is 2.99%. The results are same as the FAAS. Chapter three: Determination of potassium ion in mantichorula grandis semenow by fast atom bombardment mass spectrometry In this study we determined of K+ in Mantichorula grandis Semenow by fast atom bombardment mass spectrometry. We use Li+ as the internal standard and the concentration of K+ was calculated from the obtained IK+/ILi+ in the mass spectrometry. We studied the effects on the result of with or without matrix, the energy of FAB and investigated the interference from the co-existent metal ions. The results are satisfied with the determination limits and RSD.