title: Electron capture dissociation of polypeptides in a three-dimensional quadrupole ion trap: Implementation and first results.
abstract: The adverse influence of the radio frequency (RF) voltage on electrons has been the main obstacle for the implementation of electron capture dissociation (ECD) in three-dimensional quadrupole ion traps (3D QITs). Here we demonstrate that the use of axial magnetic field, together with the injection of low-energy (<5 eV) electrons, in the beginning of the positive RF semi-period achieves trapping of electrons for a period of time comparable with the semi-period duration. Importantly, the energy of the electrons remains low during most of the trapping period. With this technique, which we call "magnetized electrons, in-phase injection" (MEPhI), ECD and other ion-electron reactions have become possible in a 3D QIT. Initial ECD results, including single-scan data, were obtained with dications of Substance P. The observed secondary fragmentation of ECD fragments indicates that the trapped electrons are still somewhat hotter than desired.
authors.affiliation: Laboratory for Biological and Medical Mass Spectrometry, Uppsala University, Uppsala, Sweden.
authors.forename: Oleg A
authors.initials: OA
authors.lastname: Silivra
authors.forename: Frank
authors.initials: F
authors.lastname: Kjeldsen
authors.forename: Igor A
authors.initials: IA
authors.lastname: Ivonin
authors.forename: Roman A
authors.initials: RA
authors.lastname: Zubarev
mesh_terms: D004583:Electrons; D021621:Imaging, Three-Dimensional / Q000295:instrumentation / Q000379:methods*; D007477:Ions; D013058:Mass Spectrometry / Q000295:instrumentation / Q000379:methods*; D010455:Peptides / Q000737:chemistry*; D013373:Substance P / Q000032:analysis
chemical_list: D007477:Ions; D010455:Peptides; D013373:Substance P