High-Resolution Differential Ion Mobility Separations Using Helium-Rich Gases

摘要

Analyses of complex mixtures and characterization of ionsnincreasingly involve gas-phase separations by ion mobilitynspectrometry (IMS) and particularly differential or fieldnasymmetric waveform IMS (FAIMS) based on the differencenof ion mobility in strong and weak electric fields. Thenkey advantage of FAIMS is substantial orthogonality tonmass spectrometry (MS), which makes FAIMS/MS hybridna powerful analytical platform of broad utility. However,nthe potential of FAIMS has been constrained by limitednresolution. Here, we report that the use of gas mixturesncomprising up to 75% He dramatically increases thenFAIMS separation capability, with the resolving power fornpeptides and peak capacity for protein digests reachingnand exceeding 100. The resolution gains extend to smallnmolecules, where previously unresolved isomers can nownbe separated. These performance levels open major newnapplications of FAIMS in proteomic and other biomolecularnanalyses.