Multiply pulsed collision gas for ion axialization in fourier‐transform ion cyclotron resonance mass spectrometry

Abstract
We present a new multiply pulsed collision‐gas technique forion axialization for Fourier‐transform ion cyclotron resonace (FTICR) high‐resolution mass analysis. Ions are axialized in the source trap of a dural‐trap FTICR spectrometer y aimuthal quadrupolar irradiation for several tens of seconds at a steady‐state pressure maintained y repeated pulses of coolision gas (argon), folowed by removal of the collision gas and detection at a much lower pressure after transfer to the analyzer trap. Magnitufe‐mode FTICR mass resolving power, m/Δm≈︁1770000, for [M + K]+ ions from laser‐desorbed/ionized leucne enkephalin at m/z 594 is demonstrated. This resolving power is the highest yet reported for a peptide with any type of laser desorption/ionization mass analyzer.