Granted Patent B2

US 8,680,464 · App. 13/085,761 · Granted Mar 25, 2014

Abstract

Claims (26)

1. A mass spectrometer comprising:

a mass spectrometry part for conducting mass spectrometry on a sample gas;

a sample gas introducing piping part for introducing a sample gas into said mass spectrometry part;

an opening/closing mechanism disposed between said sample gas introducing piping part and said mass spectrometry part to open/close thereby to control passage of said sample gas;

an opening/closing control part for controlling said opening/closing mechanism;

a first pump for evacuating for a side region of said opening/closing mechanism opposite to said mass spectrometry part;

an evacuation pipe for connecting said first pump and said sample gas introducing piping part together; and

an ion source disposed on a side region of said opening/closing mechanism which is the same as said mass spectrometry part and which converts said sample gas into ions.

2. The mass spectrometer according to claim 1 , wherein said opening/closing control part controls the opening/closing mechanism to open said sample gas introducing piping part for a sample gas accumulation period of said mass spectrometry part and close said sample gas introducing piping part for other periods.

3. The mass spectrometer according to claim 1 , wherein said first evacuation pump evacuates the side region of said opening/closing mechanism for said sample gas introducing piping part opposite to said mass spectrometry part to have a pressure of 1,000 Pa or greater.

4. The mass spectrometer according to claim 1 , wherein said sample gas introducing piping part comprises any one of a capillary, an orifice, and a vacuum chamber, or a plurality of any of them.

5. The mass spectrometer according to claim 1 , wherein said evacuation pipe is provided between a sample gas introduction inlet of said sample gas introducing piping part and said opening/closing mechanism.

6. The mass spectrometer according to claim 1 , wherein:

said opening/closing mechanism comprises a movable member and a movable space for said movable member; and

said movable space comprises an opening part to said sample gas introducing piping part and an opening part to said mass spectrometry part.

7. The mass spectrometer according to claim 6 , wherein:

said movable space comprises an opening part to said evacuation pipe;

said opening/closing control part controls said movable member, when passing said sample gas, to close a passage between said opening part to said sample gas introducing piping part and said opening part to said evacuation pipe and open a passage between said opening part to said sample gas introducing piping part and said opening part to said mass spectrometry part, and

said opening/closing control part controls said movable member, when not passing said sample gas, to close a passage between said opening part to said sample gas introducing piping part and said opening part to said mass spectrometry part and open a passage between said opening part to said sample gas introducing piping part and said opening part to said evacuation pipe.

8. The mass spectrometer according to claim 6 , wherein a direction from said movable space to said opening part to said sample gas introducing piping part and a direction from said movable space to said opening part to said mass spectrometry part form an angle which is greater than 90° and which is 180° or less.

9. The mass spectrometer according to claim 1 , wherein said opening/closing mechanism is an opening/closing gate provided between said sample gas introducing piping part and said mass spectrometry part.

10. The mass spectrometer according to claim 1 , wherein

said mass spectrometry part comprises a second evacuation pump for evacuation, and

said second evacuation pump is coupled to said evacuation pipe and a backpressure side of said second evacuation pump is evacuated by said first evacuation pump.

11. The mass spectrometer according to claim 10 , wherein said first evacuation pump evacuates the side region of said opening/closing mechanism for said sample gas introducing piping part opposite to said mass spectrometry part to have a pressure of 100 Pa or greater and 2,500 Pa or less.

12. The mass spectrometer according to claim 1 , further comprising a pre-trap part for trapping said sample gas introduced into said mass spectrometry part.

Assignments (83)