Ion Mobility Mass Spectrometry: Instrumentation and Applications

Abstract

The integration of ion mobility spectrometry with mass spectrometry (as an IM-MS hybrid instrument) provides additional analytical separation and identification capabilities that have greatly advanced various fields, including biomedical, pharmaceutical, and forensic sciences. In this chapter, a comprehensive exploration of various IMS instrumentation platforms is discussed, including Drift tube (DTIMS), Traveling wave (TWIMS), Trapped (TIMS), Field asymmetric waveform (FAIMS), and Differential mobility analyzer (DMA). Their respective advantages and limitations are evaluated in the context of distinct applications, including isomer separation, signal filtering to increase signal-to-noise ratio, and collision cross section (CCS) measurements in targeted and untargeted omics-based workflows. The scanning rate compatibility between various IMS devices and different mass analyzers resulted in various IM-MS hyphenation platforms. Higher sensitivity and selectivity are further achieved with the introduction of tandem IMS such as TIMS-TIMS-MS. IMS separations occur in the millisecond range and can therefore be easily incorporated into the liquid chromatography-mass spectrometry workflows and coupled with ambient ionization MS for metabolomics, lipidomic, proteomics, etc. The emergence of high-resolution IMS instruments such as Cyclic Ion Mobility Spectrometry (cIMS) and Structures for lossless ion manipulations (SLIM) is also discussed for the improvement of separation of isomers and increased predictive accuracy of CCS by machine learning models.