US 6,672,133 B1Granted

Biological classification system

AssigneeThe United States of America as represented by the Secretary of the Army

InventorsWaleed M. Maswadeh, Dhirajlal G. Parekh, A. Peter Snyder, Ashish Tripathi

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Abstract

A hand-held chemical vapor detector for detecting biological substances in an indoor and outdoor setting is claimed. More specifically, the present invention relates to a plasma chromatograph (PC) vapor detector that is interfaced to a biological sample processing and transfer introduction system. The biological sample processing was accomplished by quartz tube thermal decomposition (TD), and the resultant vapor was transferred by gas chromatography (GC) to the PC detector. This system is comprised of a thermal decomposition module, gas chromatography module and a plasma chromatograph detector. These components are connected in a series fashion. The device is referred to as a Biological Classifier System (BCS). The BCS can be described as a hyphenated device where two analytical dimensions (the GC and PC), in series, allow the separation and isolation of individual components from the thermal decomposition of biological analytes.

Claims33

Dependent claims

A biological classification system, comprising:

a thermal decomposition tube for processing a biological sample and producing a resultant vapor;
wherein said thermal decomposition tube comprises:
an elongated tube having a first side with an entrance and a second side with an exit;
an interface housing supporting said second side of said elongated tube;
a microfiber filter positioned within said tube across the diameter of said tube to separate said first side from said second side, and wherein a quartz frit is permanently fixed juxtapose to the microfiber filter in the second side of said tube;
an elongated vapor sampling tube positioned inside said thermal decomposition tube, said vapor sampling tube having an entrance end and an exit end, said vapor sampling tube held in place at the exit end by said interface housing, wherein said exit end extends to an outside of said interface housing, said entrance end positioned a distance D from said quartz frit;
a heating element wrapped around an outer circumference of said elongated tube for causing a heated region;
a cooling fan assembly for cooling the heated region;
and
a tube vent in said interface housing;
a gas chromatography module interfaced with said thermal decomposition tube by a three-way injection valve, said gas chromatography module for receiving said resultant vapor from said thermal decomposition tube;
and a plasma chromatograph vapor detector interfaced via a GC/PC interface with said gas chromatography module for receiving resultant vapor from said gas chromatography module;
wherein said thermal decomposition tube, said gas chromatography module and said plasma chromatograph vapor detector are connected in series for separation, isolation and classification of individual components from the thermal decomposition of biological analytes introduced into the thermal decomposition tube.

10 more elements

A biological classification system, comprising:

a thermal decomposition tube for processing a biological sample and producing a resultant vapor;
a gas chromatography module interfaced with said thermal decomposition tube by a three-way injection valve, said gas chromatography module for receiving said resultant vapor from said thermal decomposition tube;
wherein the gas chromatography module comprises:
a GC column ring structure comprising a continuous capillary column repeatedly wound in a direction transverse to the direction of the ring structure in a toroidal manner;
said capillary column having an entrance end and an exit end;
a temperature sensing thermocouple wire connected to an electronic circuit for converting a temperature-induced electrical current to a digital output, said thermocouple wire residing inside the capillary column windings, forming a single wire ring inside of said ring structure;
a heating wire jacket around said ring structure for providing heat to the GC column;
and
a GC cooling fan;
and a plasma chromatograph vapor detector interfaced via a GC/PC interface with said gas chromatography module for receiving resultant vapor from said gas chromatography module;
wherein said thermal decomposition tube, said gas chromatography module and said plasma chromatograph vapor detector are connected in series for separation, isolation and classification of individual components from the thermal decomposition of biological analytes introduced into the thermal decomposition tube.

8 more elements

A biological classification system, comprising:

(A) a thermal decomposition tube for processing a biological sample and producing a resultant vapor, wherein said thermal decomposition tube comprises
(a) an elongated tube having a first side with an entrance and a second side with an exit;
(b) an interface housing supporting said second side of said elongated tube;
(c) a microfiber filter positioned within said tube across the diameter of said tube to separate said first side from said second side, and wherein a quartz frit is permanently fixed juxtapose to the microfiber filter in the second side of said tube;
(d) an elongated vapor sampling tube positioned inside said thermal decomposition tube, said vapor sampling tube having an entrance end and an exit end, said vapor sampling tube held in place at the exit end by said interface housing, wherein said exit end extends to on outside of said interface housing, said entrance end positioned a distance D from said quartz frit;
(e) a plurality of heating wires wrapped around an outer circumference of said elongated tube;
and
(f) a tube vent in said interface housing;
(B) a gas chromatography module interfaced with said thermal decomposition tube by a three-way injection valve, said gas chromatography module for receiving said resultant vapor from said thermal decomposition tube,
(aa) wherein said three-way injection valve provides vapor sample injection into the gas chromatography module and comprises:
(bb) an inlet interface region for receiving said exit end of said vapor sampling tube of said thermal decomposition tube, said inlet interface region further having a airflow entrance;
(cc) an outlet interface region for interfacing with said gas chromatography module at an entrance of said gas chromatography module, said outlet interface region further having an airflow exit;
and
(dd) a valve region having an injector orifice valve between said inlet interface region and said outlet interface region of said three-way valve, said valve region further having an injector airflow inlet, and
wherein the gas chromatography module comprises:
(ee) a GC column ring structure comprising a continuous capillary column repeatedly wound in a direction transverse to the direction of the ring structure in a toroidal manner;
said capillary column having an entrance end and an exit end;
(ff) a temperature sensing thermocouple wire connected to an electronic circuit for converting a temperature-induced electrical current to a digital output, said thermocouple wire residing inside the capillary column windings, forming a single wire ring inside of said ring structure;
(gg) a heating wire jacket around said ring structure for providing heat to the GC column;
and
(hh) a GC cooling fan;
and
(C) plasma chromatograph vapor detector interfaced via a GC/PC interface with said gas chromatography module for receiving resultant vapor from said gas chromatography module, wherein said GC/PC interface comprises
(aaa) an interface flange for providing an electrical and thermal isolation between the gas chromatography exit and a front end of said plasma chromatograph;
(bbb) a plasma chromatograph ionization region in proximity to the gas chromatography exit at a region A;
(ccc) a plasma chromatograph internal airflow for directing a vapor sample that elutes out of the gas chromatograph column exit into the ionization region;
(ddd) an outlet branch airflow exit tube for providing a sweep airflow through said region A and directing the vapor sample through region A into the ionization region;
(eee) and a cell pressure port with a vacuum pump associated therewith to provide a reduced pressure in the plasma chromatograph, wherein said gas chromatography column ring is heated to the gas chromatography exit and said vapor sample is eluted into said room temperature region A without condensation of the vapor sample or cold spots in the gas chromatograph column;
and
wherein said thermal decomposition tube, said gas chromatography module and said plasma chromatograph vapor detector are connected in series for separation, isolation and classification of individual components from the thermal decomposition of biological analytes introduced into the thermal decomposition tube.

27 more elements

Dependencies are inferred from the claim text.