title: Isobar Separation in a Multiple-Reflection Time-of-Flight Mass Spectrometer by Mass-Selective Re-Trapping.
abstract: A novel method for (ultra-)high-resolution spatial mass separation in time-of-flight mass spectrometers is presented. Ions are injected into a time-of-flight analyzer from a radio frequency (rf) trap, dispersed in time-of-flight according to their mass-to-charge ratios and then re-trapped dynamically in the same rf trap. This re-trapping technique is highly mass-selective and after sufficiently long flight times can provide even isobaric separation. A theoretical treatment of the method is presented and the conditions for optimum performance of the method are derived. The method has been implemented in a multiple-reflection time-of-flight mass spectrometer and mass separation powers (FWHM) in excess of 70,000, and re-trapping efficiencies of up to 35% have been obtained for the protonated molecular ion of caffeine. The isobars glutamine and lysine (relative mass difference of 1/4000) have been separated after a flight time of 0.2 ms only. Higher mass separation powers can be achieved using longer flight times. The method will have important applications, including isobar separation in nuclear physics and (ultra-)high-resolution precursor ion selection in multiple-stage tandem mass spectrometry. Graphical Abstract ᅟ.
authors.affiliation: II. Physikalisches Institut, Justus-Liebig-Universität Gießen, 35392, Gießen, Germany.|GSI Helmholtzzentrum für Schwerionenforschung GmbH, 64291, Darmstadt, Germany.
authors.forename: Timo
authors.initials: T
authors.lastname: Dickel
authors.affiliation: II. Physikalisches Institut, Justus-Liebig-Universität Gießen, 35392, Gießen, Germany. wolfgang.r.plass@exp2.physik.uni-giessen.de.|GSI Helmholtzzentrum für Schwerionenforschung GmbH, 64291, Darmstadt, Germany. wolfgang.r.plass@exp2.physik.uni-giessen.de.
authors.forename: Wolfgang R
authors.initials: WR
authors.lastname: Plaß
authors.affiliation: II. Physikalisches Institut, Justus-Liebig-Universität Gießen, 35392, Gießen, Germany.
authors.forename: Wayne
authors.initials: W
authors.lastname: Lippert
authors.affiliation: II. Physikalisches Institut, Justus-Liebig-Universität Gießen, 35392, Gießen, Germany.
authors.forename: Johannes
authors.initials: J
authors.lastname: Lang
authors.affiliation: Institute for Analytical Instrumentation, Russian Academy of Sciences, 190103, St. Petersburg, Russia.
authors.forename: Mikhail I
authors.initials: MI
authors.lastname: Yavor
authors.affiliation: II. Physikalisches Institut, Justus-Liebig-Universität Gießen, 35392, Gießen, Germany.|GSI Helmholtzzentrum für Schwerionenforschung GmbH, 64291, Darmstadt, Germany.
authors.forename: Hans
authors.initials: H
authors.lastname: Geissel
authors.affiliation: II. Physikalisches Institut, Justus-Liebig-Universität Gießen, 35392, Gießen, Germany.|GSI Helmholtzzentrum für Schwerionenforschung GmbH, 64291, Darmstadt, Germany.
authors.forename: Christoph
authors.initials: C
authors.lastname: Scheidenberger
keywords: High-resolution precursor ion selection; Isobar separator; Multiple-reflection time-of-flight mass spectrometer; Tandem mass spectrometry; Tandem-in-time