Investigations into the use of areverse scan in a quadrupole ion trap mass spectrometer
- 30 July 2003
- journal article
- research article
- Published by Wiley in Rapid Communications in Mass Spectrometry
- Vol. 17 (14), 1657-1664
- https://doi.org/10.1002/rcm.1101
Abstract
The forward scan (i.e. an increasing RF voltage ramp for the mass-selective instability scan) is commonly used as an analytical scan for ion detection with quadrupole ion trap instruments. A number of phenomena have been observed while using this scan technique. These include space charge effects resulting in the delayed ejection of ions from the ion trap, and the fragmentation of fragile ions producing very broad peaks. Here the use of a reverse scan (i.e. a decreasing RF voltage ramp) is examined to determine the effect of the above phenomena in this acquisition method. With regard to space charge effects, the apparent reduction of the carbon isotope spacing below one Thomson (for singly charged ions) that is observed with the forward scan is now replaced by an apparent increase in this spacing. The reverse scan, which optimizes at lower axial modulation ejection voltages than the forward scan, allows for the intact ejection of fragile ions under its typical operating conditions whereas the forward scan results in fragmentation. Reducing the axial modulation voltage for the ejection of ions in the forward scan results in less dissociation of the fragile ions during ion ejection, but with the observation of ghost peaks due to incomplete ejection of all of the ions at the resonance ejection condition. While performing the reverse scan experiment, the formation of product ions from dissociation of the MH(+) ion has also been observed.Keywords
This publication has 19 references indexed in Scilit:
- Origin of mass shifts in the quadrupole ion trap: dissociation of fragile ions observed with a hybrid ion trap/mass filter instrumentRapid Communications in Mass Spectrometry, 2000
- Chemical Mass Shifts in Ion Trap Mass Spectrometry: Experiments and SimulationsAnalytical Chemistry, 1999
- Improvements in LC/Electrospray Ion Trap Mass Spectrometry Performance Using an Off-Axis NebulizerAnalytical Chemistry, 1999
- Systematic factors affecting high mass-resolution and accurate mass assignment in a quadrupole ion trapInternational Journal of Mass Spectrometry and Ion Processes, 1995
- Mass shifts and local space charge effects observed in the quadrupole ion trap at higher resolutionInternational Journal of Mass Spectrometry and Ion Processes, 1995
- Investigation of ‘ghost’ peaks caused by non-linear fields in the ion trap mass spectrometerRapid Communications in Mass Spectrometry, 1995
- Evaluation of the dipole moments of organic ions in the gas phaseJournal of Mass Spectrometry, 1994
- Mass displacements in quadrupolar field analysersJournal of Mass Spectrometry, 1993
- Some alternative scanning methods for the ion trap mass spectrometerInternational Journal of Mass Spectrometry and Ion Processes, 1991
- Recent improvements in and analytical applications of advanced ion trap technologyInternational Journal of Mass Spectrometry and Ion Processes, 1984