title: Adaptation of a 3-D quadrupole ion trap for dipolar DC collisional activation.
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.
authors.affiliation: Department of Chemistry, Purdue University, West Lafayette, IN 47907-2084, USA.
authors.forename: Boone M
authors.initials: BM
authors.lastname: Prentice
authors.forename: Robert E
authors.initials: RE
authors.lastname: Santini
authors.forename: Scott A
authors.initials: SA
authors.lastname: McLuckey
mesh_terms: D000595:Amino Acid Sequence; D004743:Enkephalin, Leucine / Q000737:chemistry; D008958:Models, Molecular; D008969:Molecular Sequence Data; D010455:Peptides / Q000737:chemistry; D053719:Tandem Mass Spectrometry / Q000295:instrumentation* / Q000379:methods*
chemical_list: D010455:Peptides; D004743:Enkephalin, Leucine