Ion mobility spectrometry and the omics: Distinguishing isomers, molecular classes and contaminant ions in complex samples
Ion mobility spectrometry (IMS) is a widely used analytical technique providing rapid gas phase separations. IMS alone is useful, but its coupling with mass spectrometry (IMS-MS) and various front-end separation techniques has greatly increased the molecular information achievable from omic analyses, including the sensitivity and peak capacity extracted from complex biological and environmental sample analyses. Due to these characteristics, IMS-MS is rapidly gaining attention for improving metabolomic, lipidomic, glycomic, proteomic and exposomic analyses. Numerous studies including national security-related analyses, disease screenings and environmental evaluations are illustrating that IMS-MS is able to extract information not possible with MS alone. Furthermore, IMS-MS has shown great utility in salvaging molecular information for low abundance molecules of interest when high concentration contaminant ions are present in the sample. This review highlights how IMS-MS is currently being used in omic analyses to distinguish structurally similar molecules, isomers, molecular classes and contaminant ions.