Multi-pressure stage mass spectrometer and methods

Patent metadata

Field	Value
Publication number	US-9343280-B2
Application number	US-67677808-A
Country	US
Kind code	B2
Filing date	Sep 8, 2008
Priority date	Sep 7, 2007
Publication date	May 17, 2016
Grant date	May 17, 2016

Abstract

A mass spectrometer includes a plurality of guide stages for guiding ions between an ion source and an ion detector along a guide axis. Each of the guide stages is contained within one of a plurality of adjacent chambers. Pressure in each of the plurality of chambers is reduced downstream along the guide axis to guide ions along the axis. Each guide stage may further include a plurality of guide rods for producing a containment filed for containing ions about the guide axis, as they are guided to the detector.

First claim

What is claimed is:

1. A mass spectrometer, comprising:
a plurality of guide stages for guiding ions between an ion source and an ion detector along a guide axis;
an ion interface for guiding a transport gas and ions entrained therein, said ion interface comprising a casing having a sampling inlet in flow communication with an ion source that ionizes particles of interest and an outlet in communication with a first one of said plurality of guide stages and that slows said transport gas to a generally laminar flow in a laminar flow region;
each of said guide stages contained within one of a plurality of adjacent chambers;
said ion interface and said guide stages defining a continuous flow path from said ion source to said ion detector, for guiding said transport gas and ions entrained therein from said ion source by way of said sampling inlet to said ion detector and wherein said transport gas is provided from said laminar flow region to said guide stages;
at least one pump in flow communication with said plurality of chambers to establish a pressure regime in said plurality of chambers, and along said guide axis
in which pressure in each of said plurality of chambers is reduced downstream along said guide axis, and the pressure between said ion interface and a first one of said plurality of chambers differs at a location in said first one of said plurality of chambers by about an order of magnitude, and the pressure at a location in said first one of said plurality of chambers differs from the pressure at a location in a second one of said plurality of chambers by about an order of magnitude, and wherein said pressure regime provides a non-abrupt pressure gradient along said guide axis, to smoothly guide ions entrained in said transport gas along said guide axis from stage to stage of said plurality of guide stages.

2. The mass spectrometer of claim 1 , wherein the pressure of the first one of said plurality of chambers differs from the pressure of the second one of said plurality of chambers by less than about 20 fold.

3. The mass spectrometer of claim 1 , wherein the pressure of the first one of said plurality of chambers differs from the pressure of the second one of said plurality of chambers by less than about 10 fold.

4. The mass spectrometer of claim 1 , wherein the pressure at the outlet of said ion interface and the pressure of the first one of said plurality of chambers differs by less than about 20 fold.

5. The mass spectrometer of claim 1 , wherein said at least one pump is in direct flow communication with said first one of said guide stages, and wherein said ion interface comprises a gas inlet and wherein said outlet and said at least one pump are sized to establish a desired pressure in both said first one of said guide stages and in said ion interface.

6. The mass spectrometer of claim 1 , wherein two adjacent ones of said plurality of guide stages are interconnected by an opening, and wherein said at least one pump is in direct flow communication with the downstream one of said two adjacent guide stages, and not the upstream one of said two adjacent guide stages, and wherein said opening and said at least one pump are sized to establish a desired pressure in both said two adjacent ones of said guide stages.

7. The mass spectrometer of claim 1 , further comprising a sampling cone in at least one of said guide stages.

8. The mass spectrometer of claim 1 , comprising four of said chambers, wherein pressure within said four chambers is maintained, respectively, at about at least one Torr; at least several hundred milliTorr; at least one milliTorr; and at least one micro-Torr.

9. The mass spectrometer of claim 1 , comprising four of said chambers, wherein pressure within said four chambers is maintained, respectively, at about 10 Torr; 1 Torr; and 200 milliTorr.

10. The mass spectrometer of claim 1 , comprising four of said chambers, wherein pressure within said four chambers is maintained, respectively, at about 2 Torr; 200 milliTorr; several milliTorr; and several micro-Torr.

11. The mass spectrometer of claim 1 , comprising three of said chambers, wherein pressure within said ion interface, and said three chambers is maintained, respectively, at about at least one Torr; at least several hundred milliTorr; at least one milliTorr; and at least one micro-Torr.

12. The mass spectrometer of claim 1 , comprising three of said chambers, wherein pressure within said ion interface, and said three chambers is maintained, respectively, at about 10 Torn 1 Torr; and 200 milliTorr.

13. The mass spectrometer of claim 1 , comprising three of said chambers, wherein pressure within said ion interface, and said three chambers is maintained, respectively, at about 2 Torn 200 milliTorr; several milliTorr; and several micro-Torr.

14. The mass spectrometer of claim 1 , wherein said at least one pump comprises at least one multi-stage pump.

15. The mass spectrometer of claim 14 , wherein said at least one multi-stage pump comprises a turbomolecular pump.

16. The mass spectrometer of claim 1 , wherein at least some of said guide stages each comprise a plurality of guide rods arranged about said guide axis to establish a containment field about said guide axis.

17. The mass spectrometer of claim 1 , wherein at least some one of said guide stages comprise four guide rods arranged in quadrupole.

18. The mass spectrometer of claim 1 , wherein one set of guide rods extend through multiple ones of said guide stages.

19. The mass spectrometer of claim 1 , wherein said ion interface comprises a split flow interface, having an ion inlet, said outlet in flow communication with a first one of said guide stages, and an exit in flow communication with a roughing pump.

20. The mass spectrometer of claim 1 , wherein said ion interface is a thru-flow interface, and comprises a gas inlet and wherein all gas through said gas inlet passes through said outlet of said ion interface.

21. The mass spectrometer of claim 1 , wherein at least one of said plurality of chambers contains at least two sets of guide rods.

22. The mass spectrometer of claim 1 , wherein said at least one pump provides a single vacuum and is in flow communication with conductance limiting orifices to multiple of said plurality of chambers, to provide a desired pressure in said plurality of chambers.

23. The mass spectrometer of claim 1 , wherein at least some of said chambers comprises at least one conductance limiting orifice in flow communication with said at least one pump, and wherein said at least one conductance limiting orifice is sized to provide a desired pressure within each of said chambers.

24. The mass spectrometer of claim 1 , wherein openings connecting adjacent chambers are sized to provide a desired pressure within each of said chambers.

25. The mass spectrometer of claim 1 , wherein one of said guide stages comprises one of a collision cell, a mass filter, and a mass resolver.

26. The mass spectrometer of claim 1 , wherein the number of said guide stages exceeds the number of said at least one pump.

27. The mass spectrometer of claim 23 , wherein the number of said guide stages exceeds the number of said at least one pump.

28. A method guiding ions between an ion source and an ion detector along a guide axis in a mass spectrometer, said method comprising:
providing a plurality of guide stages, each contained

Assignees

• Cousins Lisa
• Javahery Gholamreza
• Jolliffe Charles
• Savtchenko Serguei
• Perkinelmer Health Sciences Canada Inc

Inventors

• Cousins Lisa
• Javahery Gholamreza
• Jolliffe Charles
• Savtchenko Serguei

Classifications

• H01J49/24

  Vacuum systems, e.g. maintaining desired pressures · CPC title

• H01J49/004 Primary

  Combinations of spectrometers, tandem spectrometers, e.g. MS/MS, MSn · CPC title