Chemical sampler and method

• US 20050079626A1
• Filed: 05/22/2003
• Published: 04/14/2005
• Est. Priority Date: 05/30/2002
• Status: Active Grant

• Current Assignee: Massachusetts Institute of Technology
• Original Assignee: Massachusetts Institute of Technology
• Inventors: Kunz, Roderick R.
• Granted Patent: US 7,687,276 B2
• Time in Patent Office: Days
• US Class Current: 436/164
• CPC Class Codes: G01N 1/2208 with impactors
• CPC Class Codes: G01N 1/2273 Atmospheric sampling
• CPC Class Codes: G01N 1/24 Suction devices G01N1/22 - G01N1/2294 take precedence
• CPC Class Codes: G01N 1/44 Sample treatment involving radiation, e.g. heat
• CPC Class Codes: G01N 2001/022 sampling for security purposes, e.g. contraband, warfare agents
• CPC Class Codes: G01N 2001/2276 Personal monitors
• CPC Class Codes: G01N 2015/019 Biological contaminants; Fouling
• CPC Class Codes: G01N 2015/0261 using impactors
• CPC Class Codes: G01N 2030/0085 the desorption energy being adapted to sample, e.g. laser tuned to molecular bonds
• CPC Class Codes: G01N 2030/128 Thermal desorption analysis

Abstract

A method for collecting and concentrating trace chemicals for subsequent analysis by virtually any type of chemical detector includes providing directed radiation to a sample, or a portion of a sample. An apparatus can include a sampling body for providing radiation.

Claims

1. A method of analyzing a sample comprising:

applying radiation to a sample in contact with a vaporization space; and

detecting an analyte in the vaporization space.

2. The method of claim 1, wherein the radiation is UV or VUV radiation.

3. The method of claim 1, wherein the vaporization space is at ambient pressure.

4. The method of claim 1, wherein the vaporization space is at a temperature less than 100°

C.

5. The method of claim 1, wherein applying radiation includes irradiating the sample with a non-laser radiation source.

6. The method of claim 1, wherein applying radiation includes irradiating the sample with a laser radiation source.

7. The method of claim 1, further comprising vaporizing the analyte from the sample to form an analyte vapor.

8. The method of claim 7, further comprising concentrating the analyte vapor before detecting the analyte.

9. The method of claim 7, wherein a charge of a molecule of the analyte vapor is the same as a charge of a molecule of the analyte.

10. The method of claim 7, further comprising transporting the analyte vapor to a detector with a carrier gas.

11. The method of claim 7, wherein the carrier gas is air.

12. The method of claim 10, wherein the carrier gas is an inert gas.

13. The method of claim 1, wherein the sample is an article of commerce.

14. The method of claim 1, wherein the sample includes a non-volatile material.

15. The method of claim 1, wherein the radiation is applied from a radiation source in a sampling unit, the sampling unit including the vaporization space.

16. The method of claim 15, wherein the sampling unit is portable.

17. The method of claim 1, wherein the detector includes an ion mobility spectrometer, a surface acoustic wave device, an artificial nose, a gas chromatograph, a chemiluminescence detector, a fluorescence detector, a fluorescence-quenching detector, a flame ionization detector, a flame photometric detector, or an infrared spectrometer.

18. The method of claim 1, wherein the sample includes paper, wood, plastic, metal, or fabric.

19. The method of claim 1, wherein the sample is an article of clothing.

20. The method of claim 1, wherein the analyte is a drug.

21. The method of claim 1, wherein the analyte is an explosive or a residue of an explosive.

22. The method of claim 1, wherein the analyte is a poison or a pollutant.

23. The method of claim 1, wherein the sample includes an aerosol particle.

24. The method of claim 1, further comprising collecting an aerosol particle on a surface to form a sample.

25. A method of analyzing a sample comprising:

applying UV or VUV radiation to a sample in contact with a vaporization space to vaporize an analyte from the sample and form an analyte vapor;

concentrating the analyte; and

detecting the analyte with a detector.

26. The method of claim 25, wherein the vaporization space is at ambient pressure.

27. The method of claim 25, wherein the vaporization space is at a temperature less than 100°

C.

28. The method of claim 25, wherein the sample includes a non-volatile material.

29. The method of claim 25, wherein applying radiation includes irradiating the sample with a non-laser radiation source.

30. The method of claim 25, wherein applying radiation includes irradiating the sample with a laser radiation source.

31. The method of claim 25, further comprising transporting the analyte vapor to the detector with a carrier gas.

32. The method of claim 31, wherein the carrier gas is air.

33. The method of claim 31, wherein the carrier gas is an inert gas.

34. The method of claim 25, wherein the sample is an article of commerce.

35. The method of claim 25, wherein a charge of a molecule of the analyte vapor is the same as a charge of a molecule of the analyte.

36. The method of claim 25, wherein the sample includes wood, paper, metal, plastic, or fabric.

37. The method of claim 25, wherein the sample is an article of clothing.

38. The method of claim 25, wherein the analyte is a drug.

39. The method of claim 25, wherein the analyte is an explosive or a residue of an explosive.

40. The method of claim 25, wherein the analyte is a poison or a pollutant.

41. The method of claim 25, wherein the sample includes an aerosol particle.

42. The method of claim 25, further comprising collecting an aerosol particle on a surface to form a sample.

43. An apparatus comprising:

a sampling unit including a radiation source and a vaporization space including a sample; and

a detector in vapor communication with the vaporization space.

44. The apparatus of claim 43, wherein the radiation source includes a source of UV or VUV radiation.

45. The apparatus of claim 44, wherein the radiation source includes a lamp.

46. The apparatus of claim 44, wherein the radiation source includes a laser.

47. The apparatus of claim 43, wherein the vaporization space is at ambient pressure.

48. The apparatus of claim 43, wherein the vaporization space is at a temperature less than 100°

C.

49. The apparatus of claim 43, wherein the sampling unit is portable.

50. The apparatus of claim 49, wherein the detector is portable.

51. The apparatus of claim 50, further comprising a carrier gas source.

52. The apparatus of claim 51, wherein the carrier gas source includes a source of air.

53. The apparatus of claim 51, wherein the carrier gas source includes a source of inert gas.

54. The apparatus of claim 43, wherein the vaporization space is configured to be positioned over the sample.

55. The apparatus of claim 43, wherein the sampling unit includes an aerosol particle impactor.

56. The apparatus of claim 43, further comprising a preconcentrator in vapor communication with the vaporization space and the detector.

57. The apparatus of claim 43, wherein the detector is separated from the sampling body by a vapor conduit configured to communicate vapor between the vaporization space and the detector.

58. The apparatus of claim 43, wherein the detector includes an ion mobility spectrometer, a surface acoustic wave device, an artificial nose, a gas chromatograph, a chemiluminescence detector, a fluorescence detector, a fluorescence-quenching detector, a flame ionization detector, a flame photometric detector, or an infrared spectrometer.