title: Controlled ion ejection from an external trap for extended m/z range in FT-ICR mass spectrometry.
abstract: An auxiliary rf waveform of the same amplitude and phase applied to all the rods of an ion accumulation multipole creates an m/z-dependent axial pseudo potential. Controlled decrease of the auxiliary rf amplitude releases ions from the accumulation multipole sequentially from high to low m/z. The slope of the auxiliary rf voltage ramp is adjusted so that ions of different m/z reach the center of the ICR cell at the same time point, which mitigates the typical time dispersion observed in external source FT-ICR and extends the observable mass range for a single data acquisition by 2- to 3-fold. For complex mixture analysis, twice the number of elemental compositions are assigned when the auxiliary rf ejection is applied compared with the standard gated trapping.
authors.affiliation: Ion Cyclotron Resonance Program National High Magnetic Field Laboratory, Florida State University, Tallahassee, FL, 32310-4005, USA, kaiser@magnet.fsu.edu.
authors.forename: Nathan K
authors.initials: NK
authors.lastname: Kaiser
authors.forename: Joshua J
authors.initials: JJ
authors.lastname: Savory
authors.forename: Christopher L
authors.initials: CL
authors.lastname: Hendrickson