Space charge effects on relative peak heights in fourier transform-ion cyclotron resonance spectra

  • Uechi G
  • Dunbar R
  • 5


    Mendeley users who have this article in their library.
  • 38


    Citations of this article.


Ion trajectory calculations have confirmed that space charge interactions can be a source for mass discrimination seen in Fourier transform-ion cyclotron resonance (FT-ICR) spectra. As compared with the previously recognized mechanism of z-axis excitation, ion-ion repulsion is a mechanism which specifically affects relative peak heights of ions close in mass, and is most severe for low excitation radiofrequency (rf) amplitudes. In this mechanism, Coulomb repulsion significantly perturbs the motion of the ion clouds during excitation and alters the final cyclotron orbital radii. Under these conditions peak heights do not accurately reflect the true ion abundances in the FT-ICR spectrometer. Mass discrimination can be minimized by using low numbers of ions, low ion densities, and a short, high amplitude rf excitation waveform. Experimental observation of the relative peak heights of the m/z 91, 92, and 134 ions in n-butylbenzene gives quantitative confirmation of the results of the trajectory calculations. Chirp, SWIFT, and impulse excitation were modeled: impulse excitation was found to be most effective in minimizing the effects of space charge interactions. © 1992 American Society for Mass Spectrometry.

Get free article suggestions today

Mendeley saves you time finding and organizing research

Sign up here
Already have an account ?Sign in

Find this document


  • Guy T. Uechi

  • Robert C. Dunbar

Cite this document

Choose a citation style from the tabs below

Save time finding and organizing research with Mendeley

Sign up for free