Baseline resolution of isomers by traveling wave ion mobility mass spectrometry: investigating the effects of polarizable drift gases and ionic charge distribution
Baseline resolution of isomers by traveling wave ion mobility mass spectrometry: investigating the effects of polarizable drift gases and ionic charge distribution
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DOI：
10.1002/jms.3245
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发表时间：
2013-09-01
影响因子：
2.3
通讯作者：
Campuzano, Iain D. G.
中科院分区：
文献类型：
--
作者：
Lalli, Priscila M.;Corilo, Yuri E.;Campuzano, Iain D. G.
我们用行波离子迁移质谱（TWIM-MS）研究了异构体和类似物的行为，使用不同质量和极化率的漂移气体。尽管电池的长度减少了（18厘米），一对结构异构体，N-丁基苯胺和对丁基苯胺，在氦（He）中的理论碰撞截面值相差仅1.2埃（2）（1.5%），但具有相反的电荷分布，显示出其质子化分子的基线峰间分辨率（Rp-p），使用二氧化碳（CO2），一氧化二氮（N2 O）和乙烯（C2 H4）作为TWIM漂移气体。一组质子化卤代苯胺（对氯苯胺、对溴苯胺和对碘苯胺）在CO2中也获得了接近基线的Rp-p，它们显示出相反的质量和理论值（He），相差多达15.7埃（2）（19.5%），但电荷分布相似。反式油酸和顺式油酸的去质子化异构体对具有几乎相同的理论（He）和（N2）以及相似的电荷分布，仍然没有得到解决。有趣的是，当比较He、N-2和N2 O时，观察到1，3-二烷基咪唑离子的漂移时间反转。利用密度泛函理论研究离子的电子结构，采用He和N-2轨道方法，讨论了长程电荷诱导的偶极吸引力和短程货车范德华力对不同极化率漂移气体TWIM分离的影响.因此，我们建议，检查所调查的离子的电子结构可能会潜在地表明是否使用更极化的漂移气体可以提高分离和TWIM-MS分析的整体成功。版权所有（c）2013约翰威利父子有限公司
We have studied the behavior of isomers and analogues by traveling wave ion mobility mass spectrometry (TWIM-MS) using drift-gases with varying masses and polarizabilities. Despite the reduced length of the cell (18cm), a pair of constitutional isomers, N-butylaniline and para-butylaniline, with theoretical collision cross-section values in helium ((He)) differing by as little as 1.2 angstrom(2) (1.5%) but possessing contrasting charge distribution, showed baseline peak-to-peak resolution (Rp-p) for their protonated molecules, using carbon dioxide (CO2), nitrous oxide (N2O) and ethene (C2H4) as the TWIM drift-gas. Near baseline Rp-p was also obtained in CO2 for a group of protonated haloanilines (para-chloroaniline, para-bromoaniline and para-iodoaniline) which display contrasting masses and theoretical (He), which differ by as much as 15.7 angstrom(2) (19.5%) but similar charge distributions. The deprotonated isomeric pair of trans-oleic acid and cis-oleic acid possessing nearly identical theoretical (He) and (N2) as well as similar charge distributions, remained unresolved. Interestingly, an inversion of drift-times were observed for the 1,3-dialkylimidazolium ions when comparing He, N-2 and N2O. Using density functional theory as a means of examining the ions electronic structure, and He and N-2-based trajectory method algorithm, we discuss the effect of the long-range charge induced dipole attractive and short-range Van der Waals forces involved in the TWIM separation in drift-gases of differing polarizabilities. We therefore propose that examining the electronic structure of the ions under investigation may potentially indicate whether the use of more polarizable drift-gases could improve separation and the overall success of TWIM-MS analysis. Copyright (c) 2013 John Wiley & Sons, Ltd.