Muller Hugo B, Scholl Georges, Far Johann, De Pauw Edwin, Eppe Gauthier
Mass Spectrometry Laboratory, University of Liège, Liège 4000, Belgium.
Anal Chem. 2023 Dec 5;95(48):17586-17594. doi: 10.1021/acs.analchem.3c03039. Epub 2023 Nov 17.
Over the past decade, the separation efficiency achieved by linear IMS instruments has increased substantially, with state-of-the-art IM technologies, such as the trapped ion mobility (TIMS), the cyclic traveling wave ion mobility (cTWIMS), and the structure for lossless ion manipulation (SLIM) platforms commonly demonstrating resolving powers in excess of 200. However, for complex sample analysis that require front end separation, the achievement of such high resolving power in TIMS is significantly hampered, since the ion mobility range must be broad enough to analyze all the classes of compounds of interest, whereas the IM analysis time must be short enough to cope with the time scale of the preseparation technique employed. In this paper, we introduce the concept of sliding windows in ion mobility (SWIM) for chromatography hyphenated TIMS applications that bypasses the need to use a wide and fixed IM range by using instead narrow and mobile ion mobility windows that adapt to the analytes' ion mobility during chromatographic separation. GC-TIMS-MS analysis of a mixture of 174 standards from several halogenated persistent organic pollutant (POP) classes, including chlorinated and brominated dioxins, biphenyls, and PBDEs, demonstrated that the average IM resolving power could be increased up to 40% when the SWIM mode was used, thereby greatly increasing the method selectivity for the analysis of complex samples.
在过去十年中，线性离子迁移谱（IMS）仪器所实现的分离效率大幅提高，采用诸如捕获离子迁移率（TIMS）、循环行波离子迁移率（cTWIMS）以及无损离子操控结构（SLIM）平台等先进的离子迁移谱技术，通常可实现超过200的分辨率。然而，对于需要前端分离的复杂样品分析而言，TIMS中要实现如此高的分辨率会受到显著阻碍，因为离子迁移率范围必须足够宽以分析所有感兴趣的化合物类别，而离子迁移谱分析时间又必须足够短以应对所采用的预分离技术的时间尺度。在本文中，我们引入了用于联用色谱 - TIMS应用的离子迁移率滑动窗口（SWIM）概念，该方法通过使用窄且可移动的离子迁移率窗口来替代宽且固定的离子迁移率范围，这些窗口在色谱分离过程中能适应分析物的离子迁移率。对包含氯代和溴代二恶英、联苯以及多溴二苯醚等几类卤代持久性有机污染物（POP）的174种标准品混合物进行的气相色谱 - TIMS - 质谱分析表明，当使用SWIM模式时，平均离子迁移率分辨率可提高多达40%，从而极大地提高了复杂样品分析方法的选择性。
