Efficient injection of low-mass ions into high magnetic field Fourier transform ion cyclotron resonance mass spectrometers
Article first published online: 15 DEC 2013
Copyright © 2013 John Wiley & Sons, Ltd.
Rapid Communications in Mass Spectrometry
Volume 28, Issue 2, pages 230–238, 30 January 2014
How to Cite
Zekavat, B., Szulejko, J. E., LaBrecque, D., Olaitan, A. D. and Solouki, T. (2014), Efficient injection of low-mass ions into high magnetic field Fourier transform ion cyclotron resonance mass spectrometers. Rapid Commun. Mass Spectrom., 28: 230–238. doi: 10.1002/rcm.6768
- Issue published online: 5 DEC 2013
- Article first published online: 15 DEC 2013
- Manuscript Accepted: 15 OCT 2013
- Manuscript Revised: 14 OCT 2013
- Manuscript Received: 10 JUL 2013
- Civilian Research Development Foundation (CRDF), Department of Defense (DOD). Grant Number: CDMRP-OC060322
Low-mass cut-off restrictions for injecting ions from external ion sources into high magnetic fields impose limitations for wide mass range analyses with Fourier transform ion cyclotron resonance (FTICR) instruments. Radio-frequency (RF)-only quadrupole ion guides (QIGs) with higher frequencies can be used to overcome low-mass cut-off in FTICR instruments.
RF signals (1.0 MHz to 10.0 MHz) were applied to QIGs to transfer externally generated ions from either electron ionization (EI) or electrospray ionization (ESI) sources into ICR cells of 9.4 T FTICR mass spectrometers. Efficiencies of QIGs were evaluated using externally generated ions from: EI of acetone, air, and perfluorotributylamine mixture, EI of gas chromatography (GC)-separated components of a standard sample mixture, and ESI of complex mixtures such as petroleum and fulvic acid samples.
We were able to transfer ions with m/z as low as 26 from an external EI source into the ICR cell of a 9.4 T FTICR mass spectrometer and extend the operational low-mass range for ESI-FTICR analyses. High mass resolving power and mass measurement accuracy of GC/FTICR mass spectrometry were utilized to discriminate between oxygenated and non-oxygenated compounds in a 'Grob' sample. Ion losses based on SIMION ion trajectory predictions were consistent with experimental findings.
We demonstrated that the use of high-frequency QIGs can extend the operational lower m/z range for both external EI- and ESI-FTICR mass spectrometers. By considering both ICR and Mathieu equations of motions to describe ion trajectories, theoretical ion ejection thresholds (consistent with our experimental findings) could be predicted. Copyright © 2013 John Wiley & Sons, Ltd.