Targeted Analysis for Tandem Mass Spectrometry
First Claim
1. A method of tandem mass spectrometry, comprising the steps of:
- a) generating precursor ions in an ion source;
b) guiding the precursor ions into an ion injector;
c) ejecting the precursor ions from the ion injector towards an ion guide, via an ion gate, so that the precursor ions arrive at the said ion gate only once on their passage to the ion guide, the precursor ions arriving as a temporally separated plurality of ion packets each containing ions of a respective one of a plurality of different ion species;
d) controlling the ion gate so as to sequentially select from the plurality of ion packets arriving at the ion gate, a subset of a plurality of ion packets deriving from a subset of precursor ion species of interest;
e) mixing the selected subset of a plurality of ion packets in the ion guide; and
f) analyzing the resulting ion population derived from the mixed selected subset of ion packets in a high resolution mass analyzer.
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Accused Products
Abstract
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.
10 Citations
29 Claims
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1. A method of tandem mass spectrometry, comprising the steps of:
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a) generating precursor ions in an ion source; b) guiding the precursor ions into an ion injector; c) ejecting the precursor ions from the ion injector towards an ion guide, via an ion gate, so that the precursor ions arrive at the said ion gate only once on their passage to the ion guide, the precursor ions arriving as a temporally separated plurality of ion packets each containing ions of a respective one of a plurality of different ion species; d) controlling the ion gate so as to sequentially select from the plurality of ion packets arriving at the ion gate, a subset of a plurality of ion packets deriving from a subset of precursor ion species of interest; e) mixing the selected subset of a plurality of ion packets in the ion guide; and f) analyzing the resulting ion population derived from the mixed selected subset of ion packets in a high resolution mass analyzer. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20)
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21. A tandem mass spectrometer comprising:
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an ion source for generating precursor ions; an ion injector arranged downstream of the ion source, for ejecting precursor ions received from the ion source towards a downstream ion guide; a single pass ion gate, arranged in a path of precursor ions ejected from the ion injector towards the downstream ion guide, the precursor ions arriving at the ion gate as a plurality of temporally separated ion packets each containing ions of a respective one of a plurality of different ion species; an ion gate controller configured to control the single pass ion gate so as to permit passage of only a subset of ion packets containing a respective subset of a plurality of precursor ion species of interest; wherein the ion guide is configured to receive precursor ions that are permitted to pass through the single pass ion gate;
the tandem mass spectrometer further comprising;a high resolution mass analyzer arranged to analyze the ions or their fragments. - View Dependent Claims (22, 23, 24, 25, 26, 27, 28, 29)
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Specification