Chemical sensing device

Abstract

A chemical sensing system includes a substrate material, a detector capable of indicating a presence of a target compound, gas, or vapor, and a heater for rapidly releasing compounds, gases and vapors from the substrate material. The substrate material acts to concentrate the compounds, gases, and vapors from a sample area for improved detection by the detector.

What is claimed is: 
     
         1 . A preconcentrator comprising a cartridge and a substrate having a resistivity of about 10 5  ohm-meters (Ω·m) to about 10 −7  Ω·m enclosed within the cartridge. 
     
     
         2 . The preconcentrator of  claim 1 , wherein the substrate is selected from the group consisting of metal fiber, woven metal fibers, non-woven metal fibers, porous metal, sheet metal, metal coated glass, metal coated plastic, metal coated ceramic, carbonaceous material, graphite, charcoal, activated carbon, activated carbon cloth, and combinations thereof. 
     
     
         3 . The preconcentrator of  claim 1 , wherein the substrate has a magnetic permeability of greater than about 1×10 −4  H/m, relative permeability of greater than 100, or combinations thereof. 
     
     
         4 . The preconcentrator of  claim 1 , wherein the substrate has an electrical resistivity of greater than 10 3  Ω·m. 
     
     
         5 . The preconcentrator of  claim 1 , wherein the cartridge further comprises at least a first reversibly sealable opening on one side of the cartridge and at least a second reversibly sealable opening on the opposite side of the cartridge. 
     
     
         6 . A method for detecting a chemical comprising:
 collecting particles and gases in a preconcentrator comprising a cartridge and a substrate having a resistivity of about 10 5  ohm-meters (Ω·m) to about 10 −7  Ω·m enclosed within the cartridge;   heating the substrate to release the particles and gases; and   detecting the chemical.   
     
     
         7 . The method of  claim 6 , wherein the substrate has a magnetic permeability of greater than about 1×10 −4  H/m, relative permeability of greater than 100, or combinations thereof. 
     
     
         8 . The method of  claim 6 , wherein heating is carried out to about 200° C. to about 350° C. 
     
     
         9 . The method of  claim 6 , wherein the heating is inductive heating. 
     
     
         10 . The method of  claim 9 , wherein inductive heater is carried out at a frequency of about 100 kHz to about 10 MHz. 
     
     
         11 . A sample collector comprising:
 a sample collector housing having a preconcentrator holder sized to reversibly receive a preconcentrator; and   an air suction pump operably connected to the sample collector housing and configured to produce air flow through the preconcentrator.   
     
     
         12 . The sample collector of  claim 11 , further comprising a pulsed air nozzle connected to the sample collector housing. 
     
     
         13 . The sample collector of  claim 11 , further comprising an air compressor operably connected to the sample collector housing and is configured to expel air from the pulsed air nozzle and direct the expelled air toward a sample collection area. 
     
     
         14 . The sample collector of  claim 11 , wherein the air suction pump provides a flow of 1 m 3 /min to 10 m 3 /min. 
     
     
         15 . A system comprising:
 a sample collector comprising:   a sample collector housing having a preconcentrator holder sized to reversibly receive a preconcentrator;   a detector comprising:   a detector housing having an detector access port sized to reversibly receive the preconcentrator;   an induction heater contained within the detector housing, the induction heater configured to heat the preconcentrator; and   a sensing system connected to the access port and positioned to receive desorbed gases from the preconcentrator when the preconcentrator is received by the detector.   
     
     
         16 . The system of  claim 15 , further comprising an air suction pump operably connected to the sample collection housing and configured to produce air flow through the preconcentrator. 
     
     
         17 . The system of  claim 16 , wherein the air suction pump provides a flow of 1 m 3 /min to 10 m 3 /min. 
     
     
         18 . The system of  claim 15 , wherein the sample collector further comprises a pulsed air nozzle connected to the sample collector housing. 
     
     
         19 . The system of  claim 18 , further comprising an air compressor operably connected to the sample collector housing and configured to expel air from the pulsed air nozzle and direct the expelled air toward a sample collection area. 
     
     
         20 . The system of  claim 15 , wherein preconcentrator comprises a cartridge and a substrate having a resistivity of about 10 5  ohm-meters (Ω·m) to about 10 −7  Ω·m enclosed within the cartridge. 
     
     
         21 . The system of  claim 15 , wherein the detector comprises a temperature feedback that limits the temperature to about 200° C. to about 350° C. 
     
     
         22 . The system of  claim 15 , wherein the detector further comprises a compressor operably connected to the detector access port and configured to generate a differential pressure across the preconcentrator when the preconcentrator is received by the detector.