Increasing Analytical Separation and Duty Cycle with Nonlinear Analytical Mobility Scan Functions in TIMS-FT-ICR MS

Anal Chem. 2018 Feb 20;90(4):2446-2450. doi: 10.1021/acs.analchem.7b04053. Epub 2018 Feb 8.


In this work, nonlinear, stepping analytical mobility scan functions are implemented to increase the analytical separation and duty cycle during tandem Trapped Ion Mobility Spectrometry and FT-ICR MS operation. The differences between linear and stepping scan functions are described based on length of analysis, mobility scan rate, signal-to-noise, and mobility resolving power. Results showed that for the linear mobility scan function only a small fraction of the scan is sampled, resulting in the lowest duty cycle 0.5% and longest experiment times. Implementing nonlinear targeted scan functions for analysis of known mobilities resulted in increased duty cycle (0.85%) and resolving powers (R up to 300) with a 6-fold reduction in time from 30 to 5 min. For broad range characterization, a nonlinear mobility stepping scan function provided the best sensitivity, resolving power, duty cycle (4%), and points per peak. The applicability of nonlinear mobility scan functions for the analysis of complex mixtures is illustrated for the case of a direct infusion of a MCF-7 breast cancer cell digest, where isobaric peptides (e.g., DFTPAELR and TTILQSTGK) were separated in the mobility domain (RIMS: 110) and identified based on their CCS, accurate mass (RMS: 550k), and tandem MS using IRMPD in the ICR cell.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.