Patent ID: 8624179

Claim:
A mass spectrometer comprising: a first device arranged and adapted to react first ions with one or more neutral, Non-ionic or uncharged superbase reagent gases or vapours in order to reduce the charge state of said first ions, wherein said first device comprises a Proton Transfer Reaction Device; characterized in that: said first device comprises a first ion guide comprising a plurality of electrodes, having at least one aperture wherein ions are transmitted, in use, through said apertures and wherein said one or more neutral, non-ionic or uncharged superbase reagent gases or vapours are selected from the group consisting of: (i) 1,1,3,3-Tetramethylguanidine (“TMG”); (ii) 2,3,4,6,7,8,9,10-Octahydropyrimidol[1,2-a]azepine {Synonym: 1,8-Diazabicyclo[5.4.01]undec-7-ene (“DBU”)}; and (iii) 7-Methyl-1,5,7-triazabicyclo[4.4.01]dec-5-ene (“MTBD”){Synonym: 1,3,4,6,7,8-Hexahydro-1-methyl-2H-pyrimido[1,2-a]pyrimidine}; and in that said mass spectrometer further comprises: an Electron Transfer Dissociation device arranged upstream of said first device, wherein said Electron Transfer Dissociation device comprises a second ion guide comprising a plurality of electrodes, wherein said second ion guide comprises a plurality of electrodes, having at least one aperture wherein ions are transmitted, in use, through said apertures; and a DC voltage device arranged and adapted to apply one or more first transient DC voltages or one or more first transient DC voltage waveforms to at least some of said plurality of electrodes comprising said first ion guide or said second ion guide in order to drive or urge at least some ions along and through at least a portion of the axial length of said first ion guide or said second ion guide.