Fundamental Studies of the Mechanisms of Desolvated Ion Formation from Small Charged Droplets

该研究项目由分析和表面化学项目支持，研究高电荷微米级液滴的动力学和时间演化。加州理工学院的Beauchamp教授正在进行的这项工作的目标是确定脱溶离子的形成机制，这为质谱分析中使用的电喷雾离子源中的离子形成提供了基本的基础。电喷雾电离是非常有用的大型生物重要分子的质谱分析。利用离子迁移率光谱法结合染料标记液滴的荧光探针来探测其电离机理。为了确定电喷雾电离源质谱仪中溶剂损失和离子形成的机理，本课题对单液滴离子迁移率进行了研究。迁移率测量加上激光诱导的液滴荧光标记将提供离子脱溶过程的时间依赖信息。对离子形成机制的进一步了解将提高质谱法在大型生物重要化合物结构分析中的适用性。

This research project, supported in the Analytical and Surface Chemistry Program, addresses the dynamics and temporal evolution of highly charged micron sized droplets. The goal of the work being carried out by Professor Beauchamp at CalTech is to determine the mechanism of formation of desolvated ions, which provides the fundamental basis of ion formation in electrospray ion sources used in mass spectrometry. Electrospray ionization is very useful for the mass spectrometric analysis of large biologically significant molecules. The ionization mechanism is probed by the use of ion mobility spectrometry coupled with fluorescence probing of dye tagged droplets. %%% In order to determine the mechanism of solvent loss and ion formation in the electrospray ionization source mass spectrometer, this research project is investigating single droplet ion mobility. Mobility measurements coupled with laser induced fluorescence tagging of droplets will provide time dependent information on the ion desolvation process. An increased understanding of the ion formation mechanism will improve the applicability of mass spectrometry to the structural analysis of large, biologically significant compounds.