Means and method for guiding ions in a mass spectrometer

• US 20040149902A1
• Filed: 06/15/2001
• Published: 08/05/2004
• Est. Priority Date: 06/15/2001
• Status: Active Grant

• Current Assignee: Bruker Scientific LLC (Bruker Corporation)
• Original Assignee: Bruker Daltonics, Inc. (Bruker Corporation)
• Inventors: Park, Melvin A.
• Granted Patent: US 6,956,205 B2
• Time in Patent Office: Days
• US Class Current: 250/288
• CPC Class Codes: H01J 49/063 Multipole ion guides, e.g. quadrupoles, hexapoles
• CPC Class Codes: H01J 49/107 Arrangements for using several ion sources

Abstract

A multipole ion guide capable of incorporating a plurality of ion sources (i.e., MALDI, ESI, EI/CI, etc.) to provide and analyze ions in a mass analyzer (i.e., ICR, TOF, quadrupole, etc.) has been designed. Such multipole ion guides comprise an array of pairs of parallel conducting rods (i.e., 3 pair, 4 pair, 5 pair, etc.), each pair being equally spaced from one another, with the array being bound on its top and bottom as well as its ends by DC electrodes. The ion guide then utilizes RF/DC potentials to accept ions from any of a multitude of ion sources to facilitate their transmission through differentially pumped regions to a high pressure mass analysis region.

Claims

1. An apparatus for a mass spectrometer, wherein said apparatus comprises:

at least one pair of conducting rods;

at least one capping electrode;

means for applying voltages to said conducting rods; and

means for applying voltages to said capping electrodes;

wherein said conducting rods are aligned in parallel, wherein said at least one capping electrode bounds said conducting rods, and wherein said at least one capping electrode comprises at least one opening.

2. An apparatus according to claim 1, wherein said at least one capping electrode comprises a plurality of openings.

3. An apparatus according to claim 2, wherein at least one of said openings accepts sample ions.

4. An apparatus according to claim 2, wherein at least one of said openings provides access through said ion guide for a laser beam to ionize a sample material.

5. An apparatus according to claim 1, wherein said ion guide focuses sample ions.

6. An apparatus according to claim 1, wherein said apparatus traps sample ions therein for ion selection.

7. An apparatus according to claim 1, wherein said apparatus traps sample ions therein for ion fragmentation.

8. An apparatus according to claim 1, wherein each said conducting rod is positioned equidistant from a vertical axis.

9. An apparatus according to claim 1, wherein said apparatus transfers sample ions from an ionization region to a mass analysis region.

10. An apparatus according to claim 9, wherein said mass analysis region comprises a time-of-flight mass analyzer.

11. An apparatus according to claim 9, wherein said mass analysis region comprises a quadrupole mass analyzer.

12. An apparatus according to claim 9, wherein said mass analysis region comprises a quadrupole ion trap mass analyzer.

13. An apparatus according to claim 9, wherein said mass analysis region comprises a Fourier transform ion cyclotron resonance mass analyzer.

14. An apparatus according to claim 9, wherein said mass analysis region comprises an ion mobility mass analyzer.

15. An apparatus according to claim 9, wherein said ionization region comprises an ion production means.

16. An apparatus according to claim 15, wherein said ion production means is atmospheric pressure chemical ionization.

17. An apparatus according to claim 15, wherein said ion production means is electrospray ionization.

18. An apparatus according to claim 15, wherein said ion production means is matrix-assisted laser desorption/ionization.

19. An apparatus according to claim 15, wherein said ion production means is secondary ionization.

20. An apparatus according to claim 15, wherein said ion production means is fast atom bombardment ionization.

21. An apparatus for analyzing chemical species, wherein said apparatus comprises:

at least one ion production region;

an ion guide, said ion guide having a plurality of conducting electrodes and at least one capping electrode;

means for applying voltages to said ion guide;

a plurality of vacuum stages; and

an analysis region;

wherein said ion guide accepts sample ions from any said ion production region, and wherein said ion guide transfers said sample ions to said analysis region.

22. An apparatus according to claim 21, wherein at least one of said capping electrodes comprises at least one opening.

23. An apparatus according to claim 22, wherein at least one of said openings accepts said sample ions from at least one said ionization region.

24. An apparatus according to claim 22, wherein at least one of said openings provides access through said ion guide for a laser beam to ionize a sample material.

25. An apparatus according to claim 21, wherein said ion guide focuses sample ions.

26. An apparatus according to claim 21, wherein said ion guide traps sample ions therein for ion selection.

27. An apparatus according to claim 21, wherein said ion guide traps sample ions therein for ion fragmentation.

28. An apparatus according to claim 21, wherein each said conducting rod is positioned equidistant from a vertical axis.

29. An apparatus according to claim 21, wherein said analysis region comprises a time-of-flight mass analyzer.

30. An apparatus according to claim 21, wherein said analysis region comprises an ion mobility analyzer.

31. An apparatus according to claim 21, wherein said analysis region comprises a quadrupole mass analyzer.

32. An apparatus according to claim 21, wherein said analysis region comprises a quadrupole ion trap mass analyzer.

33. An apparatus according to claim 21, wherein said analysis region comprises a Fourier transform ion cyclotron resonance mass analyzer.

34. An apparatus according to claim 21, wherein said ion production region comprises an ion production means.

35. An apparatus according to claim 21, wherein said ion production means is electrospray ionization.

36. An apparatus according to claim 21, wherein said ion production means is atmospheric pressure chemical ionization.

37. An apparatus according to claim 21, wherein said ion production means is matrix-assisted laser desorption/ionization.

38. An apparatus according to claim 21, wherein said ion production means is glow discharge.

39. An apparatus according to claim 21, wherein said ion production means is secondary ionization.

40. An apparatus according to claim 21, wherein said ion production means is fast atom bombardment.

41. A method for analyzing chemical species in a mass spectrometer comprising an ion production means, at least one multipole ion guide, a vacuum system, and a mass analyzer, said method comprising the steps of:

(a) producing ions in an ion production region;

(b) introducing said ions into an ion guide, said ion guide comprising a plurality of conducting rods and at least one capping electrode;

(c) applying a first potential to said conducting rods such that said ions move to a central axis of said ion guide;

(d) transferring said ions from said ion guide into a mass analysis region; and

(e) conducting mass analysis of said ions.

42. A method according to claim 41, wherein said ions are produced from a plurality of said ion production means.

43. A method according to claim 41, wherein gas phase chemical reactions occur within the ion guide.

44. A method according to claim 41, wherein ion selection occurs within said ion guide.

45. A method according to claim 41, wherein ion fragmentation occurs within said ion guide.

46. A method according to claim 41, wherein said ions are transferred from said ion guide into a second ion guide before entering said mass analysis region.

47. A method according to claim 41, wherein said method further comprises the step of:

(d) applying a second potential to said capping electrode to create an electric field to trap said ions within said ion guide.