Interfaces for a photoionization mass spectrometer

• US 20030155500A1
• Filed: 12/31/2002
• Published: 08/21/2003
• Est. Priority Date: 02/09/1999
• Status: Active Grant

• Current Assignee: Rapiscan Systems Incorporated (OSI Systems Incorporated)
• Original Assignee: Syagen Technology, Inc. (Safran SA)
• Inventors: Hanold, Karl A., Syage, Jack A., Evans, Matthew D., Nies, Brian J.
• Granted Patent: US 7,119,342 B2
• Time in Patent Office: Days
• US Class Current: 250/281
• CPC Class Codes: H01J 49/04 Arrangements for introducing or extracting samples to be analysed, e.g. vacuum locks; Arrangements for external adjustment of electron- or ion-optical components
• CPC Class Codes: H01J 49/107 Arrangements for using several ion sources
• CPC Class Codes: H01J 49/162 Direct photo-ionisation, e.g. single photon or multi-photon ionisation

Abstract

A detector system that contains two inlet port coupled to a photoionization chamber. One inlet port allows for the introduction of a test sample. The test sample may contain contaminants, drugs, explosive, etc. that are to be detected. The other port allows for the simultaneous introduction of a standard sample. The standard sample can be used to calibrate and/or diagnose the detector system. Simultaneous introduction of the standard sample provides for real time calibration/diagnostics of the detector during detection of trace molecules in the test sample. The photoizonizer ionizes the samples which are then directed into a mass detector for detection of trace molecules. The detector system may also include inlet embodiments that allow for vaporization of liquid samples introduced to a low pressure photoionizer.

Claims

1. A detector system, comprising:

a photoionizer;

a first inlet port coupled to said photoionizer;

a second inlet port coupled to said photoionzer; and

,

a detector coupled to said photoionier.

2. The system of claim 1, wherein said first inlet port includes a syringe port.

3. The system of claim 1, wherein said second inlet port includes a capillary tube.

4. The system of claim 1, wherein said first inlet port includes a capillary tube.

5. The system of claim 1, wherein said first inlet port includes a nebulizer.

6. The system of claim 1, further comprising a pump coupled to said photoionizer.

7. The system of claim 1, wherein said first inlet port includes a heating element.

8. The system of claim 1, wherein said second inlet port includes a heating element.

9. The system of claim 1, further comprising a syringe that is coupled to said first inlet port, said syringe containing a volume of air upstream from a sample.

10. The system of claim 9, wherein said syringe includes a solvent slug located downstream from the sample.

11. A detector system, comprising:

a photoionizer;

first port means for introducing a test sample to said photoionizer;

second port means for introducing a standard sample to said photoionzer; and

,

a detector coupled to said photoionier.

12. The system of claim 11, wherein said first port means includes a syringe port.

13. The system of claim 11, wherein said second port means includes a capillary tube.

14. The system of claim 11, wherein said first port means includes a capillary tube.

15. The system of claim 11, wherein said first port means includes a nebulizer.

16. The system of claim 11, further comprising pump means for diverting a portion of the test and standard samples away from said detector.

17. The system of claim 11, wherein said first port means includes a heating element.

18. The system of claim 11, wherein said second port means includes a heating element.

19. The system of claim 11, wherein said first port means includes a syringe that contains a volume of air upstream from a sample.

20. The system of claim 19, wherein said syringe includes a solvent slug located downstream from the sample.

21. A method for detecting a trace molecule in a sample, comprising:

introducing a test sample to a photoionization chamber through a first inlet port;

continuously introducing a standard sample into the photoionization chamber through a second inlet port;

photoionizing the test and standard samples;

detecting the trace molecule.

22. The method of claim 21, wherein the test sample is nebulized.

23. The method of claim 21, wherein the test sample is heated.

24. The method of claim 21, wherein a portion of the test and standard samples are diverted away from a detector that detects the trace molecule.

25. A detector, comprising:

a first ionization chamber that operates at approximately atmospheric pressure;

an ionizier coupled to said first ionization chamber;

a second ionization chamber that is coupled to said first ionization chamber and operates at a pressure significantly less than atmospheric;

a photoionizer coupled said second ionization chamber; and

,

a detector coupled to said second ionization chamber.

26. The detector of claim 25, further comprising a first capillary tube that couples said first ionization chamber to said second ionization chamber.

27. The detector of claim 26, further comprising an electrostatic lens coupled to said first capillary tube.

28. The detector of claim 26, further comprising a second capillary tube coupled to an inlet of said first capillary tube.

29. A detector, comprising:

a first ionization chamber that operates at approximately atmospheric pressure and contains a sample with a trace molecule;

first ionizier means for ionizing the sample;

a second ionization chamber that is coupled to said first ionization chamber and operates at a pressure significantly less than atmospheric;

transfer means for transferring the sample from the first ionization chamber to said second ionization chamber;

second ionizer means for ionizing the sample within said second ionization chamber; and

,

detector means for detecting the trace molecule.

30. The detector of claim 29, wherein said transfer means includes a first capillary tube.

31. The detector of claim 30, further comprising an electrostatic lens coupled to said first capillary tube.

32. The detector of claim 30, further comprising a second capillary tube coupled to an inlet of said first capillary tube.

33. A method for detecting a trace molecule within a sample, comprising:

ionizing the trace sample within a first ionization chamber at approximately atmospheric pressure;

transferring the ionized trace sample to a second ionization chamber that has a pressure significantly lower than atmospheric pressure;

ionizing the trace sample within the second ionization chamber; and

,

detecting the trace molecule.

34. The method of claim 33, further comprising introducing a second sample to the second ionization chamber.

35. A detector, comprising:

an ionization chamber;

a nebulizer inlet port coupled to said ionization chamber, said nebulizer inlet port including;

a housing with an inner channel;

a gas co-flow port coupled to said inner channel;

an inlet coupled to said inner channel;

a restrictor located within said inner channel;

a detector coupled to said ionization chamber.

36. The detector of claim 35, wherein said inlet is adapted to receive a syringe.

37. The detector of claim 35, wherein said inlet is adapted to receive a capillary tube.

38. The detector of claim 35, wherein said housing includes a heating element.

39. The detector of claim 35, further comprising a vibrator coupled to said nebulizer inlet port.

40. A detector, comprising:

an ionization chamber;

a nebulizer inlet port coupled to said ionization chamber, said nebulizer inlet port including;

a housing with an inner channel;

gas co-flow means for introducing a flow of gas into said inner channel;

inlet means for introducing a liquid sample into said inner channel;

mixing means for inducing a mixing of the gas and liquid sample;

a detector coupled to said ionization chamber.

41. The detector of claim 40, wherein said inlet means is adapted to receive a syringe.

42. The detector of claim 40, wherein said inlet means is adapted to receive a capillary tube.

43. The detector of claim 40, wherein said housing includes a heating element.

44. The detector of claim 40, further comprising vibration means for vibrating said nebulizer inlet port.

45. A method for nebulizing a sample that is introduced into an ionization chamber of a detector, comprising:

introducing a sample into an inner channel;

introducing a flow of gas into the inner channel; and

,

restricting flow through the inner channel.

46. The method of claim 45, further comprising heating the sample and the gas.

47. A syringe used to introduced a sample into a detector, comprising:

a needle;

a tube connected to said needle, said tube containing a sample located between a volume of air and a solvent slug.

48. A method to introduce a sample into a detector, comprising:

inserting a syringe into an inlet of a detector, the syringe containing a sample located between a volume of air and a solvent slug;

depressing the syringe to inject the sample, the air and the solvent slug into the detector.