II. Physikalisches Institut, Justus-Liebig-Universität Gießen, 35392, Gießen, Germany.
GSI Helmholtzzentrum für Schwerionenforschung GmbH, 64291, Darmstadt, Germany.
J Am Soc Mass Spectrom. 2017 Jun;28(6):1079-1090. doi: 10.1007/s13361-017-1617-z. Epub 2017 Mar 15.
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.
一种用于飞行时间质谱仪中超高分辨率空间质量分离的新方法。离子从射频（rf）阱中注入飞行时间分析仪，根据其质荷比在飞行时间中分散，然后在同一 rf 阱中动态重新捕获。这种再捕获技术具有很高的质量选择性，并且在足够长的飞行时间后甚至可以提供等压分离。本文提出了该方法的理论处理方法，并推导出了该方法最佳性能的条件。该方法已在多次反射飞行时间质谱仪中实现，质子化咖啡因分子离子的质量分离功率（半峰全宽）超过 70,000，再捕获效率高达 35%。仅在 0.2 ms 的飞行时间后，就可以分离等排体谷氨酰胺和赖氨酸（相对质量差异为 1/4000）。使用更长的飞行时间可以获得更高的质量分离功率。该方法将具有重要的应用，包括核物理中的等排分离和多级串联质谱中的（超）高分辨率前体离子选择。
