Ion mobility as an important tool in Metabolomics

Maxim Itkin, LSCF, MPU, WIS, Rehovot, Israel (maximit@weizmann.ac.il)
Sergey Malitsky, LSCF, MPU, WIS, Rehovot, Israel

Ion mobility spectrometry (IMS) is a technique that differentiates ions based on their size, shape, charge, mass and defined by drift time value.

The determination of a collision cross section (CCS) of an ion can be extrapolated from the observed drift time, leading to unified CCS value. Under typical operating conditions, Collision Cross Section (CCS) is a robust and precise measurement related to an ion’s structure. The information provided by CCS is independent of sample matrix and chromatography method, meaning that analytes can be confidently identified even when sample type and chromatographic conditions change. When coupled with liquid chromatography-mass spectrometry (LC-MS), IMS provides an additional dimension of separation.

The introduction of ion mobility measurements as a routine procedure into mass spectrometry become a significant tool in metabolomics experiments, allowing to discriminate between isomeric metabolite species in complex samples and enable new discoveries not possible any other way.

Knowing an CCS value helps in metabolite identification and characterization. In our work  we present a comprehensive approach which use IMS technique in order to differentiate between isomeric substances of several classes, eliminating the need to develop special chromatographic methods for the separation of such elusive molecules.