Micro scale flow through sorbent plate collection device

Abstract

In the invention, a collection device includes a flow through micro scale plate arranged to collect analyte. The plate includes holes, and sorbent coating on contact surfaces of the plate. The holes pass analyte fluid flow, for example analyte vapor so that fluid flow for collection may be generally perpendicular to the sorbent plate. Preferred embodiment plates include an integrated heater trace. In preferred embodiments, a high substantially perpendicular flow is used for collection and concentration, and during desorption and delivery a low substantially parallel flow is used. The low flow is selected to meet constraints of a detector system.

1 . An analyte collection device, the device comprising: 
 a first micro scale plate having a narrowed end;    sorbent coating on at least a portion of said first micro scale plate;    a penetrating hole through said first micro scale plate, said hole being arranged to permit passage of an analyte fluid flow through said first micro scale plate; and    a heating element for heating said sorbent coating.    
     
     
         2 . The device of  claim 1 , wherein said heating element comprises a resistive trace formed on or within said first micro scale plate.  
     
     
         3 . The device of  claim 1 , wherein said penetrating hole comprises a plurality of penetrating holes through said first micro scale plate.  
     
     
         4 . The device of  claim 3 , wherein said narrowed end is sized to match an inlet of a detector system.  
     
     
         5 . The device of  claim 4 , comprising multiple sorbent coatings formed in multiple zones of said first micro scale plate, each sorbent coating being selected to sorb a predetermined analyte.  
     
     
         6 . The device of  claim 5 , comprising separate heating elements for each of said multiple zones.  
     
     
         7 . The device of  claim 6 , wherein said narrowed end is sized to match the inlet of one of a capillary gas chromatographic column, a narrow orifice inlet to a mass spectrometer, and a micro sensor pneumatic manifold opening.  
     
     
         8 . The device of  claim 1 , wherein: 
 said heating element comprises a plurality of resistive traces formed on or within said first micro scale plate;    said resistive traces divide said micro scale plate into a plurality of zones, one of said zones being a collection zone for collecting analyte from environment, and another being a smaller delivery zone for concentrating analyte from the collection zone in a smaller area and delivering analyte to a detector system.    
     
     
         9 . The device of  claim 8 , wherein said sorbent coating is formed thicker in said smaller delivery zone than in said collection zone.  
     
     
         10 . The device of  claim 1 , further comprising a second micro scale plate with a narrowed end, sorbent coating, a penetrating hole, and heating element, said second micro scale plate being arranged downstream of said first micro scale plate such that an analyte fluid flow substantially perpendicular to said first micro scale plate is directed through said first micro scale plate and subsequently through said second micro scale plate.  
     
     
         11 . The device of  claim 10 , wherein each of said first and second micro scale plates comprises a plurality of penetrating holes.  
     
     
         12 . The device of  claim 11 , wherein said penetrating holes through said first micro scale plate are at least partially aligned with solid portions of said second micro scale plate to induce a cascading flow of analyte fluid through said first and second micro scale plates.  
     
     
         13 . The device of  claim 12 , further comprising a support for said first and second micro scale plates.  
     
     
         14 . The device of claims  13 , wherein said support comprises a housing.  
     
     
         15 . The device of  claim 13 , wherein said support comprises a frame and suspension.  
     
     
         16 . A self contained micro analytical system, comprising 
 a collection device according to  claim 10;     a detector system;    a power source; and    a controller.    
     
     
         17 . The system of  claim 16 , further comprising: 
 a housing for the collection device device;    an inlet to said housing;    an outlet from said housing; and    means for inducing the analyte fluid flow.    
     
     
         18 . The system of  claim 17 , wherein said means for inducing comprise a low power fan.  
     
     
         19 . The device of  claim 1 , wherein said first micro scale plate is formed from a semiconductor material.  
     
     
         20 . The device of  claim 19 , wherein said first semiconductor material comprises silicon.  
     
     
         21 . The device of  claim 1 , wherein said first micro scale plate is formed from a dielectric material.  
     
     
         22 . The device of  claim 21 , wherein said dielectric material comprises one of polymers, ceramics, glass, crystalline quartz, fused silica, and resins.  
     
     
         23 . The device of  claim 22 , wherein said dielectric material comprises polyimide.  
     
     
         24 . The device of  claim 1 , wherein said penetrating hole comprises a plurality of penetrating holes taking up approximately 40-60% of the surface area of said first micro scale plate.  
     
     
         25 . An analyte collection device, the device comprising: 
 a micro scale plate;    a penetrating hole through said micro scale plate, said hole being arranged to permit passage of an analyte fluid flow through said micro scale plate; and    a first resistive trace forming a first heating element defining a first zone on said micro scale plate;    a second resistive trace forming a second heating element defining a second zone on said micro scale plate; and    sorbent coating formed on at least a portion of said first zone and a portion of said second zone.    
     
     
         26 . The device of  claim 25 , wherein said sorbent coating is formed thicker in said second zone.  
     
     
         27 . The device of  claim 26 , wherein said second zone is smaller than said first zone.  
     
     
         28 . A method for concentrating analyte from an analyte fluid flow and delivering the analyte, the method comprising steps of: 
 directing the analyte fluid flow substantially perpendicular to a micro scale sorbent coated plate and through holes in the micro scale sorbent coated plate to concentrate analyte in the sorbent;    heating the sorbent; and    delivering analyte desorbed due to said heating in a flow substantially parallel to said micro scale sorbent coated plate.    
     
     
         29 . The method of  claim 28 , wherein said step of directing uses a high analyte fluid flow and said step of delivering uses a low flow substantially parallel to said micro scale sorbent coated plate.