Ion-Mobility Mass Spectrometry in Metabolomics and Lipidomics
Ion-mobility spectrometry (IMS) is an anlytical technique that provides for the separation of ions in the gas phase. The separation, occuring on a timescale of milliseconds, is based on the differing mobility of ions according to their charge, shape, and size. These characteristics make IMS suitable for coupling with mass spectrometry (MS), to serve in current MS-based workflows for metabolomics and lipidomics. IM-MS improves peak capacity and signal-to-noise ratios, and it provides more confidence during compound identification or confirmation than conventional analyses. Combining collision-induced dissociation with ion-mobility separation improves the specificity of MS/MS-based approaches. Significantly, ion-mobility-derived information provides an orthogonal, physicochemical parameter-the collision cross section (CCS)-which relates to a metabolite's shape. Novel hardware and software solutions enable analysts to process and exploit IMS-MS data for qualitative and quantitative metabolomics and lipidomics applications.