Gated Trapped Ion Mobility Spectrometry Coupled to Fourier Transform Ion Cyclotron Resonance Mass Spectrometry

Analysis of molecules by ion mobility spectrometry coupled with mass spectrometry (IMS-MS) provides chemical information on the three dimensional structure and mass of the molecules. The coupling of ion mobility to trapping mass spectrometers has historically been challenging due to the large differences in analysis time between the two devices. In this paper we present a modification of the trapped ion mobility (TIMS) analysis scheme termed "Gated TIMS" that allows efficient coupling to a Fourier Transform Ion Cyclotron Resonance (FT-ICR) analyzer. Analyses of standard compounds and the influence of source conditions on the TIMS distributions produced by ion mobility spectra of labile ubiquitin protein ions are presented. Ion mobility resolving powers up to 100 are observed. Measured collisional cross sections of ubiquitin ions are in excellent qualitative and quantitative agreement to previous measurements. Gated TIMS FT-ICR produces results comparable to those acquired using TIMS/time-of-flight MS instrument platforms as well as numerous drift tube IMS-MS studies published in the literature.