Selection of a Single Isotope of Multiply Charged Xenon (^AXe^z+, A=128–136, z=1–6) by Using a Bradbury–Nielsen Ion Gate

Abstract

The inclusion of an ion gate in a tandem mass spectrometer allows a specific precursor ion to be selected, and the fragment ions are then used for structure analysis and to investigate chemical reactions. However, the performance of an ion gate has been judged simply by whether or not the target ion was selected. In this study, we designed, manufactured, constructed, and characterized a Bradbury-Nielsen ion gate (BNG). The actual ion selection ability, i.e. the gate function, of the BNG was measured for isotopes of Xe (z=1-6). The gate function of the BNG was 36.5±0.5 ns in width and 3-13 ns in rise and fall times. The BNG provides a simple way to select multiply charged molecular cations of small organic molecules as well as large molecules such as proteins and peptides.

Charge-Dependent Metastable Dissociations of Multiply Charged Decafluorobiphenyl Formed by Femtosecond Laser Pulses

“…For product ion analysis, a specific precursor ion was selected by the BNG followed by the TOF analysis. 17) The laser beam was focused into the ionization chamber with a plano-convex quartz lens with a 200-mm focal length. For the cases of 1.4 μm laser pulses, the beam size was expanded by a Galilean-type beam expander before focusing to increase the focused laser intensity.…”

“…Figure 3 shows the magnified TOF spectra measured with or without using the BNG. The actual ion selection ability, i.e., the gate function, of BNG was 36.5±0.5 ns (fwhm) in width, 17) which was sufficient to select a monoisotopic DFB + and DFB 2+ . The width of the gate and the timing with respect to a laser pulse were optimized to maximize the signal intensity of precursor ions.…”

Charge Transfer and Metastable Ion Dissociation of Multiply Charged Molecular Cations Observed by Using Reflectron Time‐of‐Flight Mass Spectrometry

“…The experimental details have been described elsewhere. [28] Briefly, the multiple ionization of hexafluorobenzene and xenon was carried out with a linearly polarized 40-fs pulse centered at 0.8 μm (Thales laser, Alpha 100/1000/XS hybrid), and the ions were detected by a Wiley-Mclaren time-of-flight mass spectrometer (Toyama, KNTOF-1800) equipped with a Bradbury-Nielsen ion gate, [30] an offset curved field reflectron, [16][17][18] and MCP detectors (Hamamatsu Photonics, F4655-11X). Hexafluorobenzene (Aldrich, 99 %) was degassed by repeated freeze-and-thaw cycles before use.…”

Charge Transfer and Metastable Ion Dissociation of Multiply Charged Molecular Cations Observed by Using Reflectron Time‐of‐Flight Mass Spectrometry

“…The experimental details have been described elsewhere. [28] Briefly, the multiple ionization of hexafluorobenzene and xenon was carried out with a linearly polarized 40-fs pulse centered at 0.8 μm (Thales laser, Alpha 100/1000/XS hybrid), and the ions were detected by a Wiley−Mclaren time-of-flight mass spectrometer (Toyama, KNTOF-1800) equipped with a Bradbury−Nielsen ion gate, [30] an offset curved field reflectron, [16−18] and MCP detectors (Hamamatsu Photonics, F4655-11X). Hexafluorobenzene (Aldrich, 99%) was degassed by repeated freeze-and-thaw cycles before use.…”