Patent ID: 8563921

Claim:
A mass spectrometer comprising: an Electron Transfer Dissociation or Proton Transfer Reaction device comprising an ion guide comprising a plurality of electrodes; a first device arranged and adapted to apply one or more first transient DC voltages or potentials or one or more first transient DC voltage or potential waveforms to at least some of said plurality of electrodes in order to drive or urge at least some first ions along or through at least a portion of an axial length of said ion guide in a first direction; and a control system arranged and adapted to estimate, determine or measure a degree to which at least some first ions are fragmented or reduced in charge due to Electron Transfer Dissociation or Proton Transfer Reaction as said first ions are transmitted through said ion guide and in response thereto to vary, alter, increase or decrease one or more parameters which affect transmission or degree of fragmentation or degree of charge reduction of said first ions as said first ions pass through said ion guide; wherein said control system is arranged and adapted to vary, alter, increase or decrease said one or more parameters so as to vary, alter, increase or decrease a speed or velocity at which said first ions are transmitted, in use, through said ion guide; and wherein said control system is arranged and adapted to vary, alter, increase or decrease: (i) a speed or velocity at which said one or more first transient DC voltages or potentials or said one or more first transient DC voltage or potential waveforms are applied to at least some of said plurality of electrodes or are translated along the axial length of said ion guide; or (ii) an amplitude of said one or more first transient DC voltages or potentials or said one or more first transient DC voltage or potential waveforms.