Ion-mobility mass spectrometry for lipidomics applications

Among lipidomics’ major challenges, there is the molecular complexity of the lipidome. State-of-the-art technology, such as ion mobility (IM) spectrometry, is a promising new tool for supporting lipidomics research. IM is a gas-phase electrophoretic technique that enables the separation of ions in the gas phase according to their charge, shape, and size. IM separation, which occurs on a time scale of milliseconds, is compatible with modern mass spectrometers with microsecond scan speeds. Thus, IM-mass spectrometry (MS) can be integrated into conventional lipidomics MS workflows to improve separation and enhance peak capacity, spectral clarity, and fragmentation specificity. Furthermore, IM allows for the determination of the collision cross section (CCS), an orthogonal physicochemical measure that can be used, together with accurate mass and fragmentation information, to increase the confidence of lipid identification. In recent years, the expanding sophistication of hardware and software products has enabled IM-MS to perform an increasingly important role in traditional lipidomic approaches. In this chapter, we present IM-MS procedures for lipidomics research.