Dynamical Parameters of Ion Ejection and Ion Formation in Matrix-Assisted Laser Desorption/Ionization
Dynamical Parameters of Ion Ejection and Ion Formation in Matrix-Assisted Laser Desorption/Ionization
复制标题
基质辅助激光解吸/电离中离子喷射和离子形成的动力学参数
DOI：
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发表时间：
1995
期刊：
影响因子：
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通讯作者：
R. Kaufmann
中科院分区：
文献类型：
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作者：
Volker Bökelmann;B. Spengler;R. Kaufmann
描述了基质辅助激光解吸电离（MALDI）质谱中的分子喷射和电离过程。角分辨的初始速度分布的基质和分析物离子，从MALDI样品制备正常和从肽掺杂的单晶二羟基苯甲酸，离子密度图。喷射分布已被发现是双峰，包括一个缓慢的，少向前峰部分和一个快速的部分，这是针对更多的表面法线。离子图显示在高肽离子密度区域中基质离子的显著淬灭。这种效应被解释为导致质子从基质离子转移到分析物分子的气相中的离子-分子反应的结果，并且由简单的动力学重叠模型描述。讨论了固相吸收、电子激发寿命和荧光产率的附加效应。
Molecular ejection and ionization processes in matrix-assisted laser desorption/ionization (MALDI) mass spectrometry are described. Angular resolved initial velocity distributions of matrix and analyte ions, obtained both from MALDI samples prepared normally and from peptide-doped single crystals of dihydroxybenzoic acid, are presented as ion density plots. The ejection distributions have been found to be bimodal, consisting of a slow, less forward peaked fraction and a fast fraction, which is directed more towards the surface normal. The ion plots show a significant quenching of matrix ions in areas of high peptide ion density. This effect is interpreted as the result of ion–molecule reactions in the gas phase leading to proton transfer from matrix ions to analyte molecules and is described by a simple kinetic overlap model. Additional effects of solid phase absorption, electronic excitation life times and fluorescence yield are discussed.