Internal energy distributions in desorption electrospray ionization (DESI)
Internal energy distributions in desorption electrospray ionization (DESI)
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DOI：
10.1016/j.jasms.2007.11.019
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发表时间：
2008-03-01
影响因子：
3.2
通讯作者：
Cooks, R. Graham
中科院分区：
文献类型：
--
作者：
Nefliu, Marcela;Smith, Jonell N.;Cooks, R. Graham
采用“存活率”方法测量解吸电喷雾电离（DEST）产生的典型离子的内能分布，并与电喷雾电离（EST）和电声喷雾电离（ESSI）的相应数据进行比较。结果表明，三种电离方法产生的离子群具有相似形状和平均值（1.7-1.9 eV）的内部能量分布，这表明至少在从溶剂化液滴到气相离子的过程的后期阶段存在相似的现象。这些能量学数据与以下观点一致：DEST 涉及“液滴拾取”（液-液萃取），然后是类似 ESI 的去溶剂化和气相离子形成。比较了DEST和ESSI中各种实验参数对对甲氧基苄基吡啶鎓离子裂解程度的影响。结果显示，存活率随雾化气压、溶剂流速以及喷雾器尖端到 MS 入口距离的变化趋势相似。这些观察结果与上述机制一致，并且它们还使用户能够通过操纵外部和内部离子源参数来控制 DEST 电离过程的能量。
The internal energy distributions of typical ions generated by desorption electrospray ionization (DEST) were measured using the "survival yield" method, and compared with corresponding data for electrospray ionization (EST) and electrosonic spray ionization (ESSI). The results show that the three ionization methods produce populations of ions having internal energy distributions of similar shapes and mean values (1.7-1.9 eV) suggesting similar phenomena, at least in the later stages of the process leading from solvated droplets to gas-phase ions. These data on energetics are consistent with the view that DEST involves "droplet pick-up" (liquid-liquid extraction) followed by ESI-like desolvation and gas-phase ion formation. The effects of various experimental parameters on the degree of fragmentation of p-methoxy-benzylpyridinium ions were compared between DEST and ESSI. The results show similar trends in the survival yields as a function of the nebulizing gas pressure, solvent flow rate, and distance from the sprayer tip to the MS inlet. These observations are consistent with the mechanism noted above and they also enable the user to exercise control over the energetics of the DEST ionization process, through manipulation of external and internal ion source parameters.