【作者】 陈君； 吕强； 许莉； 肖红展；

【Author】 Jun Chen;Qiang Lyu;Li Xu;Hongzhan Xiao;Beijing Institute of Microchemistry;

【机构】 北京微量化学研究所；

【摘要】 介孔二氧化硅MCM-41是一种具有蜂巢状规则正六边形孔径的多孔硅材料。均匀孔径结构以及存在于表面的大量硅羟基,使得它对于极性化合物有较强的吸附能力。在激光能量较低时,MCM-41能够显著降低芳香有机酸基质的质谱信号。本研究合成的MCM-41的孔径约为2.6nm。对于2-4个氨基酸残基的小肽,MCM-41主要是表面硅羟基的作用,体现为抑制了基质分子生成气态离子,从而使得能量更多的被小肽吸收,降低了分析所需的激光能量。当氨基酸残基大于4个,则显现出了孔径的作用。当短肽分子增加氨基酸残基,极性随之增强,因此,与MCM-41表面硅羟基的吸附力变大,造成了难以在质谱图中得到分析物的相关离子信号。而如果给予较高的激光能量,则会使分析物产生裂解,难以得到MALDI中常见的分子离子峰,而是较多的碎片离子峰。更多还原

【Abstract】 Mesoporous silica nanoparticles(MCM-41) with Homogeneous 3 nm pore size has been used as matrix additive for the peptides analysis by means of MALDI-MS.Due to the surface Si-OH and porous structure,MCM-41 exhibits some unique benefits,such as reduce the matrix peaks and laser energy when analyzing peptides with no more than3 amino acid residues.However,peptide signal can not be detected if it is composed of more than 4 amino acid residues.Fragments but not molecular ion peaks are detected with much higher laser energy.The reason probably is that the peptide’s polarity and molecular size are increasing with the amount of amino acid residue.Thus,the interaction of Si-OH on the MCM-41 surface and peptide will be stronger along with the increasing of amino acid residue.In addition,the bigger the analyte,the harder it gets through the porous structure.更多还原