System and Method For Fusing Chemical Detectors

Patent metadata

Field	Value
Publication number	US-2016299102-A1
Application number	US-201615190338-A
Country	US
Kind code	A1
Filing date	Jun 23, 2016
Priority date	Aug 30, 2013
Publication date	Oct 13, 2016
Grant date	—

Abstract

Two complementary approaches to the science of IMS technology, IMS and differential IMS (DIMS), are combined into a single instrument to provide improvements in interference rejection without sacrificing detection sensitivity. The technology is applicable to, inter alia, the analysis of trace quantities of toxic or otherwise dangerous organic chemical materials. The approach improves both sensitivity and specificity (interference rejection) of field detection instrumentation.

First claim

We claim:

1 . A chemical agent detector comprising:
an ionization chamber including at least one ion source for generating positive and negative ions from a sample received therein from a first direction; a first ion mobility spectrometry cell integrated with the ionization chamber for receiving at least a first portion of the positive ions emanating therefrom in a second direction; a second ion mobility spectrometry cell integrated with the ionization chamber for receiving at least a first portion of the negative ions emanating therefrom in a third direction; a differential ion mobility spectrometry cell integrated with the ionization chamber for receiving at least a second portion of the positive ions and at least a second portion of the negative ions emanating therefrom in the first direction, wherein the sample and the differential ion mobility spectrometry cell are on opposite sides of the ionization chamber and separated thereby and the first and second ion mobility spectrometry cells are on opposite sides of the ionization chamber and separate thereby; and a processor for separately receiving first detection data from the first ion mobility spectrometry cell, second detection data from the second ion mobility spectrometry cell, and third detection data from the differential ion mobility spectrometry cell and processing the first, second and third detection data to determine presence of one or more chemical agents in the sample.

2 . The chemical agent detector according to claim 1 , wherein the ionization chamber further includes:
a front face; a back face opposite the front face; first and second side faces opposite one another and between, perpendicular to and connecting the front face and the back face; a top face perpendicular to and connecting the front face, back face and first and second side faces; wherein the front face includes at least one input port for receiving the sample into the ionization chamber, the top face includes at least one input port for receiving the ion source, the first side face includes an i/o port for passing the first portion of positive ions to the first ion mobility spectrometry cell and receiving drift gas into the ionization chamber from the first ion mobility spectrometry cell, the second side face includes an i/o port for passing the first portion of negative ions to the second ion mobility spectrometry cell and receiving drift gas into the ionization chamber from the second mobility spectrometry cell, and the back face includes and exit port for passing the second portion of positive ions, the second portion of negative ions and the drift gas to the differential ion mobility spectrometry cell;

3 . The chemical agent detector according to claim 2 , wherein the exit port to the differential ion mobility spectrometry cell further includes at least one side port for allowing a first portion of the drift gas to exit prior to entering the differential ion mobility spectrometry cell.

4 . The chemical agent detector according to claim 3 , further comprising first and second gas scrubbers for receiving a second portion of the drift gas after it has passed through the differential ion mobility spectrometry cell and the first portion of the drift gas from the at least one side port, removing contaminants therefrom and returning clean drift gas to the first and second ion mobility spectrometry cells, wherein the clean drift gas flows in an opposite direction to the first portion of positive ions and the first portion of negative ions flowing in the first and second ion mobility spectrometry cells.

5 . The chemical agent detector according to claim 1 , wherein the ion source is a corona discharge source.

6 . The chemical agent detector according to claim 1 , further comprising a mass spectrometer interfaced with an output of the differential ion mobility spectrometry cell.

7 . The chemical agent detector according to claim 1 , wherein the at least one ion source is a single ion source.

8 . The chemical agent detector according to claim 3 , wherein there are two side ports for allowing a first portion of the drift gas to exit prior to entering the differential ion mobility spectrometry cell.

9 . The chemical agent detector according to claim 1 , further comprising an indicator selected from the group consisting of audio, visual and tactile indicators for indicating when the sample contains one or more predetermined chemical agents.

10 . A hand-held chemical agent detector comprising:
an ionization chamber including at least one ion source for generating positive and negative ions from a sample, wherein the dimensions of the ionization chamber are less than 1 cm width, 2.5 cm length and 2.0 cm height; a first and second ion mobility spectrometry cells integrated with the ionization chamber on opposite sides thereof for receiving at least a first portion of the positive and negative ions therefrom, wherein the dimensions of the first and second ion mobility spectrometry cells are less than 2.5 cm width, 2.0 cm length and 2.5 cm height; and a differential ion mobility spectrometry cell integrated with the ionization chamber on a side thereof opposite the sample for receiving at least a second portion of the positive ions and at least a second portion of the negative ions therefrom, wherein the dimensions of the differential ion mobility spectrometry cell are less than 1 cm width, 1.0 cm length and 3.0 cm height.

11 . The hand-held chemical agent detector of claim 10 , the ionization chamber further including:
a front face; a back face opposite the front face; first and second side faces opposite one another and between, perpendicular to and connecting the front face and the back face; a top face perpendicular to and connecting the front face, back face and first and second side faces; wherein the front face includes at least one input port for receiving the sample into the ionization chamber, the top face includes at least one input port for receiving the ion source, the first side face includes an i/o port for passing the first portion of positive ions to the first ion mobility spectrometry cell and receiving drift gas into the ionization chamber from the first ion mobility spectrometry cell, the second side face includes an i/o port for passing the first portion of negative ions to the second ion mobility spectrometry cell and receiving drift gas into the ionization chamber from the second mobility spectrometry cell, and the back face includes and exit port for passing the second portion of positive ions, the second portion of negative ions and the drift gas to the differential ion mobility spectrometry cell.

12 . The hand-held chemical agent detector according to claim 11 , wherein the exit port to the differential ion mobility spectrometry cell further includes at least one side port for allowing a first portion of the drift gas to exit prior to entering the differential ion mobility spectrometry cell.

13 . The hand-held chemical agent detector according to claim 12 , further comprising first and second gas scrubbers for receiving a second portion of the drift gas after it has passed through the differential ion mobility spectrometry cell and the first portion of the drift gas from the at least one side port, removing contaminants therefrom and returning clean drift gas to the first and second ion mobility spectrometry cells, wherein the clean drift gas flows in an opposite direction to the first portion of positive ions and the first portion of negative ions flowing in the first and second ion mobility spectrometry cells.

14 . The hand-held_chemical agent detector ac

Assignees

• Leidos Inc

Inventors

• Harden Charles Stephen
• Schafer Robert James

Classifications

• G01N27/622 Primary

  Ion mobility spectrometry · CPC title

• G01N27/624

  Differential mobility spectrometry [DMS]; Field asymmetric-waveform ion mobility spectrometry [FAIMS] · CPC title

• H01J49/0095 Primary

  Particular arrangements for generating, introducing or analyzing both positive and negative analyte ions (ion/ion reactions H01J49/0072) · CPC title

• H01J49/004

  Combinations of spectrometers, tandem spectrometers, e.g. MS/MS, MSn · CPC title

• H01J49/0013

  Miniaturised spectrometers, e.g. having smaller than usual scale, integrated conventional components · CPC title