Method of detecting analyte vaporized from sample with low-power UV radiation

• US 7,687,276 B2
• Filed: 05/22/2003
• Issued: 03/30/2010
• Est. Priority Date: 05/30/2002
• Status: Expired due to Fees

• Current Assignee: Massachusetts Institute of Technology
• Original Assignee: Massachusetts Institute of Technology
• Inventors: Kunz, Roderick R.
• Primary Examiner(s): Gakh; Yelena G
• Application Number:
  US10/443,141
• Publication Number:
  US 20050079626A1
• Time in Patent Office: 2,504 Days
• Field of Search: None
• 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 comprising:

providing a sample;

irradiating the sample using electromagnetic radiation with a wavelength in a range from 150 nm to 270 nm and at an irradiance of 0.1-1000 mW/cm2, wherein the radiation increases an evaporation rate of an analyte within the sample, thereby causing vaporization of the analyte from the sample;

capturing the vaporized analyte in a vaporization space; and

detecting the vaporized analyte with a detector.

2. The method of claim 1, wherein the wavelength of the radiation is in a range from 170 nm to 230 nm or in a range from 150 nm to 220 nm.

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 irradiating the sample comprises irradiating the sample using a non-laser radiation source.

6. The method of claim 1, wherein irradiating the sample comprises irradiating the sample using a laser radiation source.

7. The method of claim 1, further comprising concentrating the vaporized analyte before detecting the analyte.

8. The method of claim 7, wherein the analyte is concentrated using a chilled surface, a sorptive polymer, or a permeable membrane.

9. The method of claim 1, 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 1, wherein detecting the vaporized analyte comprises transporting the analyte vapor to a detector with a carrier gas.

11. The method of claim 10, 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 comprises 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 comprising the vaporization space, wherein gas in the vaporization space can be collected in such a fashion that little if any is allowed to escape into the surrounding environment.

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

17. The method of claim 15, wherein the sampling unit is positioned over a surface of the sample so that an opening on the sampling unit is located over an area of the sample to be analyzed.

18. The method of claim 1, wherein the analyte is detected using 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.

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

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

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

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

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

24. The method of claim 1, wherein the sample comprises an aerosol particle.

25. The method of claim 24, wherein providing the sample comprises collecting the aerosol particle on a surface to form the sample.

26. The method of claim 1, wherein the radiation is vacuum ultraviolet (VUV) radiation.

27. The method of claim 1, wherein the sample is irradiated for 1-100 seconds.

28. The method of claim 1, wherein an area of the surface irradiated with the electromagnetic radiation is 0.1-100 cm².

29. The method of claim 1, wherein vaporization is non-thermal.

30. The method of claim 1, wherein capturing the analyte comprises capturing the analyte on an intermediate surface.

31. The method of claim 1, wherein the vaporization space can include additional products not present in the sample.

32. The method of claim 1, wherein the sample comprises more than one analyte.