Synthesis And Evaluation Of New Types Of Matrix Mateirals Used In Matrix Assisted Laser Desorption Ionizationmass Spectrometry

Matrix assisted laser desorption/ionization mass spectrometry (MALDI MS) ischaracterized as simple, rapid, high-throughput and high sensitive technique, and hasbeen widely used in proteomics, tissue imaging and so on. However, during theMALDI MS analysis some defects influence its application, which includes theinterferences from matrix peaks in low m/z region and poor reproducibility. Inaddition, the ionization mechanism of MALDI mass spectrometry is not clear. In thisthesis, we intend to develop new matrix materials to overcome the defects oftraditional matrixes. By doing this, we synthesized a series of compounds andevaluate their potential capability as matrixes applied in MALDI MS analysis. Inaddition, the effect of various functional groups on the effectiveness of matrixes wasalso investigated.This paper contains four chapters. The contents are listed below:In chapter one an introduction on ionization principle and hypothesis of thematrix assisted laser desorption ionization technique was given. Common matrixmaterials and sample preparation methods for MALDI mass analysis are introduced.Based on problems existing in using MALDI mass matrix experimental protocol andgoal of this thesis are proposed.In chapter two a series of esterified compounds from a common matrix ofα-cyano-4-hydroxy cinnamic acid (CHCA) were synthesized. These compounds asMALDI matrixes were used for sample analysis and matrix performance evaluation.We found that the compound α-cyano-4-hydroxyl propyl cinnamate （CHCA-C3）displayed better matrix effect for the analysis of polypeptide and proteins in terms ofreproducibility and sensitivity compared with traditional matrixes. This is attributed tobetter co-crystallization between sample and matrixes.In chapter three new matrixes were considered by incorporating the commonmatrix into polymer materials. Two different synthesis methods were used tosynthesize matrix-polymers. Unfortunately, the synthesized polymers have not features of MALDI matrix. The effect of functional groups on the synthesis andfunction of matrix are also discussed in this chapter.In chapter four a series of Schiff base compounds were synthesized. Thesecompounds were used as MALDI matrix that showed little interference in lower m/zregion than the traditional matrix. Among the compounds, the two benzene aminebenzaldehyde Schiff base (S3) showed better performance. In addition, the influenceof functional groups to the properties of Schiff base matrix is also discussed in thischapter.