(19)
(11) EP 1 365 438 A3

(12) EUROPEAN PATENT APPLICATION

(88) Date of publication A3:
12.04.2006 Bulletin 2006/15

(43) Date of publication A2:
26.11.2003 Bulletin 2003/48

(21) Application number: 02257117.8

(22) Date of filing: 14.10.2002
(51) International Patent Classification (IPC): 
H01J 49/40(2006.01)
(84) Designated Contracting States:
AT BE BG CH CY CZ DE DK EE ES FI FR GB GR IE IT LI LU MC NL PT SE SK TR
Designated Extension States:
AL LT LV MK RO SI

(30) Priority: 17.05.2002 GB 0211373
31.05.2002 GB 0212641
23.09.2002 GB 0222055

(71) Applicant: Micromass UK Limited
Manchester M22 5PP (GB)

(72) Inventor:
  • Hoyes, John Brian
    Stockport, Cheshire SK4 4JU (GB)

(74) Representative: Jeffrey, Philip Michael 
Frank B. Dehn & Co. 179 Queen Victoria Street
London EC4V 4EL
London EC4V 4EL (GB)

   


(54) Mass Spectrometer


(57) A mass spectrometer is disclosed wherein ions having a particular desired charge state are selected by operating an ion mobility spectrometer 4 in combination with a quadrupole mass filter 5. Precursor ions are fragmented or reacted to form product ions in a collision cell ion trap 6 and sent back upstream to an upstream ion trap 2. The fragment or product ions are then passed through the ion mobility spectrometer 4 wherein they become temporally separated according to their ion mobility. Fragment or product ions are then re-trapped in the collision cell ion trap 6 before being released therefrom in packets. A pusher electrode 8 of a time of flight mass analyser is energised a predetermined period of time after a packet of ions is released from the collision cell ion trap 6. Accordingly, it is possible to select multiply charged precursor ions from a background of singly charged ions, fragment them, and mass analyse the fragment ions with a near 100% duty cycle across the whole mass range.







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