Sub-part-per-million mass accuracy using a single internal calibrant on an orbitrap mass spectrometer for large-scale protein analysis

摘要

Our method of mass recalibration on an ETD-enabled linear ion trap-orbitrap hybrid mass spectrometer yields virtual complete elimination of drift, minimizing the need for manual external mass calibrations, and provides sub-part-per-million mass accuracy for both precursors and fragments. Fluoranthene cations are a convenient and reliable ion source for internal mass calibration. The scan event is implemented such that the impact on scan time (approx4 ms) and spectral quality is minimal, and can be easily incorporated into high-resolution MS~(1) as well as MS~(2) spectra, regardless of activation type. Post-acquisition mass recalibration via software is fast and straightforward.