Study on ion formation in electrospray droplet impact secondary ion mass spectrometry
Study on ion formation in electrospray droplet impact secondary ion mass spectrometry
复制标题
DOI：
10.1002/rcm.3004
复制
发表时间：
2007-01-01
影响因子：
2
通讯作者：
Hiraoka, Kenzo
中科院分区：
文献类型：
--
作者：
Asakawa, Daiki;Fujimaki, Susumu;Hiraoka, Kenzo
本文介绍了一种新型的团簇二次离子质谱（西姆斯）--电喷雾液滴碰撞（EDI）。与传统的西姆斯相比，EDI可以产生相当强的负离子和正离子。在这项工作中，在EDI离子形成的各个方面进行了研究。分析物样品中混合的布朗斯台德碱（质子受体）和酸（质子供体）分别增强了分析物的去质子化分子（负离子）和质子化分子（正离子）的信号强度。这表明水滴与沉积在金属基底上的固体样品之间的碰撞界面的冲击波加热边缘发生了非均相质子转移反应（即M + M '->[M+H]（+）+ [M '-H]（-））。EDI-SIMS显示出对样品中存在的大量过量盐的显著耐受性。EDI中的解吸/电离机制比MALDI和西姆斯中的解吸/电离机制简单得多，因为只有非常薄的样品层参与冲击波加热的织边，并且复杂的高阶反应在很大程度上被抑制。版权所有（C）2007约翰威利父子有限公司
A new type of cluster secondary ion mass spectrometry (SIMS), named electrospray droplet impact (EDI), has been developed in our laboratory. In general, rather strong negative ions as well as positive ions can be generated by EDI compared with conventional SIMS. In this work, various aspects of ion formation in EDI are investigated. The Bronsted bases (proton acceptor) and acids (proton donor) mixed in the analyte samples enhanced the signal intensities of deprotonated molecules (negative ions) and protonated molecules (positive ions), respectively, for analytes. This suggests the occurrence of heterogeneous proton transfer reactions (i.e. M + M '->[M+H](+) + [M '-H](-)) in the shockwave-heated selvedge of the colliding interface between the water droplet and the solid sample deposited on the metal substrate. EDI-SIMS shows a remarkable tolerance to the large excess of salts present in samples. The mechanism for desorption/ionization in EDI is much simpler than those for MALDI and SIMS because only very thin sample layers take part in the shockwave-heated selvedge and complicated higher-order reactions are largely suppressed. Copyright (C) 2007 John Wiley & Sons, Ltd.