Delayed extraction experiments using a repulsive potential before ion extraction: Evidence of clusters as ion precursors in UV-MALDI. Part I: Dynamical effects with the matrix 2,5-dihydroxybenzoic acid
Delayed extraction experiments using a repulsive potential before ion extraction: Evidence of clusters as ion precursors in UV-MALDI. Part I: Dynamical effects with the matrix 2,5-dihydroxybenzoic acid
复制标题
DOI：
10.1016/s1387-3806(01)00540-1
复制
发表时间：
2002-02-01
影响因子：
1.8
通讯作者：
Bolbach, G
中科院分区：
文献类型：
--
作者：
Fournier, I;Brunot, A;Bolbach, G
延迟萃取实验进行精确的动力学效应参与的离子形成的紫外基质辅助激光解吸/电离（UV-MALDI）。在离子提取之前，用排斥势仔细检查离子飞行时间随提取延迟时间的变化。根据离子的质量（基质2，5-二羟基苯甲酸和肽）和排斥电位，观察到离子飞行时间和延迟时间之间的线性关系的一些偏差。离子飞行时间的模拟清楚地表明，离子不是直接在靶表面上产生的，而是源于更高质量前体的气相分解。由基质分子包围的分析物组成的前体的大小随着分析物的大小而增加。团簇前体的完全去溶剂化可能由脉冲提取期间的高电场瞬态引起。团簇作为MALDI中离子产生的前体的存在突出了一个新的全局框架来解释UV-MALDI中的分析物质子化。(Int J Mass Spectrom 213（2002）203-215）（C）2002 Elsevier Science B.V.
Delayed extraction experiments were undertaken to precise the dynamical effects involved in the ion formation in ultraviolet matrix-assisted laser desorption/ionization (UV-MALDI). Careful examination of the ion time-of-flight variation with the extraction delay time were performed with a repulsive potential before ion extraction. Depending on the mass of the ion (matrix 2,5-dihydroxybenzoic acid and peptides') and on the repulsing potential, some deviations from the linear relationship between the ion time-of-flight and the delay time were observed. Simulations of the ion time-of-flight clearly show that ions are not directly produced on the target surface but originate from the gas-phase decomposition of higher mass precursors. The size of the precursor, composed of the analyte surrounded by matrix molecules, increases with that of the analyte. Complete desolvation of the cluster-precursor could be likely induced by the high electric field transient during the pulse extraction. The existence of clusters as precursor of the ion production in MALDI highlights a new global frame to explain the analyte protonation in UV-MALDI. (Int J Mass Spectrom 213 (2002) 203-215) (C) 2002 Elsevier Science B.V.