基体辅助激光解吸飞行时间质谱法中多电荷单体和单电荷多聚体分子离子形成机理的研究

The Formation Mechanism of Multiply Charged Monomers and Singly Charged Oligomers in Matrix Assisted Laser Desorption/Ionization Mass Spectrometry

本文主要对基体辅助激光解吸质谱法中的多电荷单体和单电荷多聚体以及多电荷多聚体分子离子的形成机理进行研究。分析了样品的化学结构、样品浓度、基体的质子亲合性和基底的导电性等对多电荷和多聚体分子离子的形成的影响。实验中发现当蛋白质样品浓度增大，单电荷多聚体分子离子强度和聚合程度都随之增大；α－氰基－４－羟基－肉桂酸较３，５－二甲氧基－４－羟基肉桂酸易产生双电荷离子；当硝化纤维膜作基底时，多电荷单体的分子离子强度增加，但单电荷多聚体分子离子强度减少，同时还出现了多电荷多聚体分子离子峰，且高分子量分子较低分子量分子显著。对上述多电荷单体和单电荷多聚体以及多电荷多聚体分子离子的形成机理，进行了理论探讨。

The influences of the chemical structure of the sample,concentration of sample solution,the proton affinity of the matrix,and the electrical conductivity of the substrate on the formation of multiply charged monomers and singly charged oligomers are investigated.Results showed that the intensity and polymerazition degree of the singly charged oligomers increase with the increase of the concentration of the sample solution;more doubly charged monome ric molecular ions are easily formed with α cyano 4 hydroxycinnamic acid as matrix than with sinapinic acid as matrix;more multiply charged monomers appeared when nitrocellulose membrane is used as substrate ,especially in case of higher mass protiens.The formation mechanism of multiply charged monomers and singly charged oligomers are discussed in this paper.