Mass Spectrometer

An Electron Transfer Dissociation or Proton Transfer Reaction device as claimed in 1, wherein:

• (a) said first device is arranged and adapted to progressively increase, progressively decrease, progressively vary, linearly increase, linearly decrease, increase in a stepped, progressive or other manner or decrease in a stepped, progressive or other manner the amplitude, height or depth of said one or more first transient DC voltages or potentials or said one or more first transient DC voltage or potential waveforms applied to said plurality of electrodes as a function of position or displacement along the length of said ion guide;
• or
• (b) said first device is arranged and adapted to reduce the amplitude, height or depth of said one or more first transient DC voltages or potentials or said one or more first transient DC voltage or potential waveforms applied to said plurality of electrodes along the length of said ion guide from a first end of said ion guide to a central or other region of said ion guide;
• or
• (c) the amplitude, height or depth of said one or more first transient DC voltages or potentials or said one or more first transient DC voltage or potential waveforms applied to said plurality of electrodes at a first position along the length of said ion guide is X, and wherein the amplitude, height or depth of said one or more first transient DC voltages or potentials or said one or more first transient DC voltage or potential waveforms applied to said plurality of electrodes at a second different position along the length of said ion guide is 0-0.05 X, 0.05-0.10 X, 0.10-0.15 X, 0.15-0.20 X, 0.20-0.25 X, 0.25-0.30 X, 0.30-0.35 X, 0.35-0.40 X, 0.40-0.45 X, 0.45-0.50 X, 0.50-0.55 X, 0.55-0.60 X, 0.60-0.65 X, 0.65-0.70 X, 0.70-0.75 X, 0.75-0.80 X, 0.80-0.85 X, 0.85-0.90 X, 0.90-0.95 X or 0.95-1.00 X;
• or
• (d) the amplitude, height or depth of said one or more first transient DC voltages or potentials or said one or more first transient DC voltage or potential waveforms applied to said plurality of electrodes reduces to zero or near zero along at least 1%, 5%, 10%, 20%, 30%, 40%, 50%, 60%, 70%, 80%, 90% or 95% of the axial length of said ion guide so that said first ions are no longer confined axially by one or more DC potential barriers;
• and
• (e) said second device is arranged and adapted to progressively increase, progressively decrease, progressively vary, linearly increase, linearly decrease, increase in a stepped, progressive or other manner or decrease in a stepped, progressive or other manner the amplitude, height or depth of said one or more second transient DC voltages or potentials or said one or more second transient DC voltage or potential waveforms applied to said plurality of electrodes as a function of position or displacement along the length of said ion guide;
• or
• (f) said second device is arranged and adapted to reduce the amplitude, height or depth of said one or more second transient DC voltages or potentials or said one or more second transient DC voltage or potential waveforms applied to said plurality of electrodes along the length of said ion guide from a second end of said ion guide to a central or other region of said ion guide;
• or
• (g) the amplitude, height or depth of said one or more second transient DC voltages or potentials or said one or more second transient DC voltage or potential waveforms applied to said plurality of electrodes at a second position along the length of said ion guide is X, and wherein the amplitude, height or depth of said one or more second transient DC voltages or potentials or said one or more second transient DC voltage or potential waveforms applied to said plurality of electrodes at a second different position along the length of said ion guide is 0-0.05 X, 0.05-0.10 X, 0.10-0.15 X, 0.15-0.20 X, 0.20-0.25 X, 0.25-0.30 X, 0.30-0.35 X, 0.35-0.40 X, 0.40-0.45 X, 0.45-0.50 X, 0.50-0.55 X, 0.55-0.60 X, 0.60-0.65 X, 0.65-0.70 X, 0.70-0.75 X, 0.75-0.80 X, 0.80-0.85 X, 0.85-0.90 X, 0.90-0.95 X or 0.95-1.00 X;
• or
• (h) the amplitude, height or depth of said one or more second transient DC voltages or potentials or said one or more second transient DC voltage or potential waveforms applied to said plurality of electrodes reduces to zero or near zero along at least 1%, 5%, 10%, 20%, 30%, 40%, 50%, 60%, 70%, 80%, 90% or 95% of the axial length of said ion guide so that said second ions are no longer contained axially by one or more potential barriers.

A mass spectrometer as claimed in 32, wherein said mass spectrometer comprises:

• a C-trap;
• and
• an orbitrap mass analyser;
• wherein in a first mode of operation ions are transmitted to said C-trap and are then injected into said orbitrap mass analyser;
• and
• wherein in a second mode of operation ions are transmitted to said C-trap and then to a collision cell or said Electron Transfer Dissociation or Proton Transfer Reaction device wherein at least some ions are fragmented into fragment ions, and wherein said fragment ions are then transmitted to said C-trap before being injected into said orbitrap mass analyser.

A method of performing Electron Transfer Dissociation or Proton Transfer Reaction reactions comprising:

• providing an Electron Transfer Dissociation or Proton Transfer Reaction device comprising an ion guide comprising a plurality of electrodes having at least one aperture, wherein ions are transmitted through the apertures;
• and
• applying 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 the axial length of said ion guide in a first direction;
• and
• applying one or more second transient DC voltages or potentials or one or more second transient DC voltage or potential waveforms to at least some of said plurality of electrodes in order to drive or urge at least some second ions along or through at least a portion of the axial length of said ion guide in a second different direction.