Gas chromatographic “in column” spectroscopic analysis

Patent metadata

Field	Value
Publication number	US-9599567-B2
Application number	US-201414208088-A
Country	US
Kind code	B2
Filing date	Mar 13, 2014
Priority date	Mar 15, 2013
Publication date	Mar 21, 2017
Grant date	Mar 21, 2017

Abstract

A chemical detector for rapid, simultaneous detection of multiple chemicals including chemical warfare agents, toxic industrial chemicals, and explosives having one or more gas chromatography columns each with a chemosorbent or a chemo-reactive stationary phase and an infrared-transparent base, a bright infrared light source, a mechanism to direct the light source to any point along any of the columns, and an infrared sensor. Another disclosed detector has one or more gas chromatography columns each on the surface of a substrate having at least one infrared-transparent waveguide pattern, a bright infrared light source, and at least one ring resonator for each column, where each ring resonator is coated with a chemosorbent or a chemo-reactive stationary phase, and where each ring resonator spectroscopically probes the stationary phase. Also disclosed are the related methods for chemical detection.

First claim

What is claimed as new and desired to be protected by Letters Patent of the United States is:

1. A chemical detector for simultaneous detection of multiple chemicals including chemical warfare agents, toxic industrial chemicals, and explosives, comprising:
one or more gas chromatography columns, wherein each column comprises one or more chemosorbent or chemo-reactive stationary phases, and wherein each column comprises an infrared evanescent waveguide configured to detect along the length of the column;
an infrared light source;
a moveable mirror to direct the light source to the more than one gas chromatography columns, wherein the light source can be directed to any point along any of the columns or to a preconcentrator or collector device, wherein in-column chemical detection can occur at all points along every column; and
an infrared sensor.

2. The chemical detector of claim 1 , wherein when there is more than one column, each column is operated in parallel.

3. The chemical detector of claim 1 , wherein at least one stationary phase comprises a carbosilane material with hydrogen bond acidic functionalization.

4. The chemical detector of claim 1 , wherein the infrared evanescent waveguide comprises an attenuated total reflection (ATR) crystal.

5. The chemical detector of claim 1 , wherein the infrared light source comprises one or more optionally tunable infrared lasers, and more preferably the bright infrared light source comprises one or more quantum cascade lasers (QCLs).

6. The chemical detector of claim 1 , additionally comprising an analyte preconcentrator comprising sorbent coated structures positioned before or at the inlet end of at least one of the columns.

7. The chemical detector of claim 1 , additionally comprising one or more independently controlled heating elements along one or more columns.

8. A method for simultaneous detection of multiple chemicals including chemical warfare agents, toxic industrial chemicals, and explosives, comprising:
injecting a vapor-phase analyte sample into one or more gas chromatography columns, wherein each column comprises one or more chemosorbent or chemo-reactive stationary phases, and wherein each column comprises an infrared evanescent waveguide configured to detect along the length of the column;
directing an infrared light source to a point at one of the columns, wherein the light source can be directed to any point along any of the columns or to a preconcentrator or collector device, wherein in-column chemical detection can occur at all points along every column; and
using an infrared sensor to detect for the presence of chemicals.

9. The method of claim 8 , wherein when there is more than one column, each column is operated in parallel.

10. The method of claim 8 , wherein at least one stationary phase comprises a carbosilane material with hydrogen bond acidic functionalization.

11. The method of claim 8 , wherein the infrared evanescent waveguide comprises an attenuated total reflection (ATR) crystal.

12. The method of claim 8 , wherein the infrared light source comprises one or more optionally tunable infrared lasers, and more preferably the bright infrared light source comprises one or more quantum cascade lasers (QCL).

13. A chemical detector for simultaneous detection of multiple chemicals including chemical warfare agents, toxic industrial chemicals, and explosives, comprising:
one or more gas chromatography columns, wherein each column is on a surface of a substrate, wherein the substrate has one or more waveguides patterned on the surface to guide light to detect one or more chemical species at a specific location at one of the gas chromatography columns, and wherein each waveguide pattern is transparent to infrared light;
an infrared light source; and
at least one ring resonator for each column, wherein each ring resonator is coated with one or more chemosorbent or chemo-reactive stationary phases, and wherein each ring resonator spectroscopically probes the stationary phase.

14. The chemical detector of claim 13 , wherein when there is more than one column, each column is operated in parallel.

15. The chemical detector of claim 13 , wherein at least one stationary phase comprises a carbosilane material with hydrogen bond acidic functionalization.

16. The chemical detector of claim 13 , wherein the infrared light comprises one or more optionally tunable infrared lasers, and more preferably the bright infrared light source comprises one or more quantum cascade lasers (QCL).

17. The chemical detector of claim 13 , additionally comprising a preconcentrator before or at the head of at least one of the columns.

18. The chemical detector of claim 13 , additionally comprising one or more independently controlled heating elements along one or more columns.

19. The chemical detector of claim 13 , wherein the detector is a hand held device.

20. A method for simultaneous detection of multiple chemicals including chemical warfare agents, toxic industrial chemicals, and explosives, comprising:
injecting a vapor-phase analyte sample into one or more gas chromatography columns, wherein each column is on a surface of a substrate, wherein the substrate has one or more waveguides patterned on the surface to guide light to detect one or more chemical species at a specific location at one of the gas chromatography columns, and wherein each waveguide pattern is transparent to infrared light;
directing an infrared light into each waveguide; and
using a ring resonator to spectroscopically probe the stationary phase of a column, wherein there is at least one ring resonator for each column, and wherein each ring resonator is coated with one or more chemosorbent or chemo-reactive stationary phases.

21. The method of claim 20 , wherein when there is more than one column, each column is operated in parallel.

22. The method of claim 20 , wherein at least one stationary phase comprises a carbosilane material with hydrogen bond acidic functionalization.

23. The method of claim 20 , wherein the infrared light source comprises one or more optionally tunable infrared lasers, and more preferably the bright infrared light source comprises one or more quantum cascade lasers (QCL).

Assignees

• Mcgill R Andrew
• Furstenberg Robert
• Nguyen Viet K
• Kendziora Chris
• Papantonakis Michael
• Stievater Todd H
• Us Navy

Inventors

• Mcgill R Andrew
• Furstenberg Robert
• Nguyen Viet K
• Kendziora Chris
• Papantonakis Michael
• Stievater Todd H

Classifications

• G01N30/74 Primary

  Optical detectors {(measurement of intensity, velocity, spectral content, polarisation, or phase of infrared, visible or ultraviolet light G01J)} · CPC title

• B01J20/285

  based on polymers · CPC title

• G01N30/02

  Column chromatography · CPC title

• G01N30/6082

  transparent to radiation · CPC title

• G01N21/7746 Primary

  the waveguide coupled to a cavity resonator · CPC title