Electron transfer dissociation device
AssigneeMicromass UK Limited
InventorsJeffery Mark Brown, Martin Raymond Green
Life of this patent
Estimating the term…
Abstract
A mass spectrometer is disclosed comprising an Electron Transfer Dissociation device comprising an ion guide. A control system determines the degree of fragmentation and charge reduction of precursor ions within the ion guide and varies the speed at which ions are transmitted through the ion guide in order to optimise the fragmentation and charge reduction process.
Claims15
A mass spectrometer comprising:
- an Electron Transfer Dissociation or Proton Transfer Reaction device comprising an ion guide comprising a plurality of electrodes;
- and
- a control system arranged and adapted:
- (i) to determine the intensity or abundance I1 of one or more parent or precursor ions having a first charge state which emerge from said ion guide;
- (ii) to determine the intensity or abundance I2 of one or more ions which emerge from said ion guide and which correspond with parent or precursor ions which have been charge reduced and which have a second charge state, wherein said second charge state is lower than said first charge state;
- and
- (iii) to vary the velocity or amplitude of one or more transient DC voltages which are applied to said electrodes in order to maintain the ratio I1/I2 or I2/I1 at a substantially constant value R with time.
A method of mass spectrometry comprising:
- providing an Electron Transfer Dissociation or Proton Transfer Reaction device comprising an ion guide comprising a plurality of electrodes;
- determining the intensity or abundance I1 of one or more parent or precursor ions having a first charge state which emerge from said ion guide;
- determining the intensity or abundance I2 of one or more ions which emerge from said ion guide and which correspond with parent or precursor ions which have been charge reduced and which have a second charge state, wherein said second charge state is lower than said first charge state;
- and
- varying the velocity or amplitude of one or more transient DC voltages which are applied to said electrodes in order to maintain the ratio I1/I2 or I2/I1 at a substantially constant value R with time.
A mass spectrometer comprising:
- an Electron Transfer Dissociation or Proton Transfer Reaction device comprising an ion guide comprising a plurality of electrodes;
- and
- a control system arranged and adapted:
- (i) to determine the intensity or abundance I1 of one or more parent or precursor ions having a first charge state which emerge from said ion guide;
- (ii) to determine the intensity or abundance I2 of one or more ions which emerge from said ion guide and which correspond with parent or precursor ions which have been fragmented;
- and
- (iii) to vary the velocity or amplitude of one or more transient DC voltages which are applied to said electrodes in order to maintain the ratio I1/I2 or I2/I1 at a substantially constant value R with time.
A method of mass spectrometry comprising:
- providing an Electron Transfer Dissociation or Proton Transfer Reaction device comprising an ion guide comprising a plurality of electrodes;
- determining the intensity or abundance I1 of one or more parent or precursor ions having a first charge state which emerge from said ion guide;
- determining the intensity or abundance I2 of one or more ions which emerge from said ion guide and which correspond with parent or precursor ions which have been fragmented;
- and
- varying the velocity or amplitude of one or more transient DC voltages which are applied to said electrodes in order to maintain the ratio I1/I2 or I2/I1 at a substantially constant value R with time.
A computer readable medium comprising computer executable instructions stored on said computer readable medium, said instructions being arranged to be executable by a control system of a mass spectrometer comprising an Electron Transfer Dissociation or Proton Transfer Reaction device comprising an ion guide comprising a plurality of electrodes, said computer program being arranged to cause said control system to:
- determine the intensity or abundance I1 of one or more parent or precursor ions having a first charge state which emerge from said ion guide;
- determine the intensity or abundance I2 of one or more ions which emerge from said ion guide and which correspond with parent or precursor ions which have been charge reduced and which have a second charge state, wherein said second charge state is lower than said first charge state;
- and
- vary the velocity or amplitude of one or more transient DC voltages which are applied to said electrodes in order to maintain the ratio I1/I2 or I2/I1 at a substantially constant value R with time.
A computer readable medium comprising computer executable instructions stored on said computer readable medium, said instructions being arranged to be executable by a control system of a mass spectrometer comprising an Electron Transfer Dissociation or Proton Transfer Reaction device comprising an ion guide comprising a plurality of electrodes, said computer program being arranged to cause said control system to:
- determine the intensity or abundance I1 of one or more parent or precursor ions having a first charge state which emerge from said ion guide;
- determine the intensity or abundance I2 of one or more ions which emerge from said ion guide and which correspond with parent or precursor ions which have been fragmented;
- and
- vary the velocity or amplitude of one or more transient DC voltages which are applied to said electrodes in order to maintain the ratio I1/I2 or I2/I1 at a substantially constant value R with time.
Dependencies are inferred from the claim text.