| 摘要 |
<p>A tandem mass spectrometer and method are described. Precursor ions are generated in an ion source (10) and an ion injector (21, 23) injects ions towards a downstream ion guide (50, 60) via a single or multi reflection TOF device (30) that separates ions into packets in accordance with their m/z. A single pass ion gate (40) in the path of the precursor ions between the ion injector (21, 23) and the ion guide (50, 60) is controlled so that only a subset of precursor ion packets, containing precursor ions of interest, is allowed onward transmission to the ion guide (50, 60). A high resolution mass spectrometer (70) is provided for analysis of those ions, or their fragments, which have been allowed passage through the ion gate (40). The technique permits multiple m/z ranges to be selected from a wise mass range of precursors, with optional fragmentation of one or more of the chosen ion species.</p> |
