Adaptation of a 3-D quadrupole ion trap for dipolar DC collisional activation

J Am Soc Mass Spectrom. 2011 Sep;22(9):1486-92. doi: 10.1007/s13361-011-0183-z. Epub 2011 Jun 23.

Abstract

Means to allow for the application of a dipolar DC pulse to the end-cap electrodes of a three-dimensional (3-D) quadrupole ion trap for as short as a millisecond to as long as hundreds of milliseconds are described. The implementation of dipolar DC does not compromise the ability to apply AC waveforms to the end-cap electrodes at other times in the experiment. Dipolar DC provides a nonresonant means for ion acceleration by displacing ions from the center of the ion trap where they experience stronger rf electric fields, which increases the extent of micro-motion. The evolution of the product ion spectrum to higher generation products with time, as shown using protonated leucine enkephalin as a model protonated peptide, illustrates the broad-band nature of the activation. Dipolar DC activation is also shown to be effective as an ion heating approach in mimicking high amplitude short time excitation (HASTE)/pulsed Q dissociation (PQD) resonance excitation experiments that are intended to enhance the likelihood for observing low m/z products in ion trap tandem mass spectrometry.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • Amino Acid Sequence
  • Enkephalin, Leucine / chemistry
  • Models, Molecular
  • Molecular Sequence Data
  • Peptides / chemistry
  • Tandem Mass Spectrometry / instrumentation*
  • Tandem Mass Spectrometry / methods*

Substances

  • Peptides
  • Enkephalin, Leucine