Ion mobility spectrometer, spectrometer analyte detection and identification verification system, and method

• US 6,495,824 B1
• Filed: 03/13/2000
• Issued: 12/17/2002
• Est. Priority Date: 03/13/2000
• Status: Expired due to Fees

• Current Assignee: Battelle Energy Alliance LLC (Battelle Memorial Institute)
• Original Assignee: Bechtel BWXT Idaho, LLC
• Inventors: Atkinson, David A.
• Primary Examiner(s): Lee, John R.
• Assistant Examiner(s): Vanore, David A.
• Application Number:
  US09/524,323
• Time in Patent Office: 1,009 Days
• Field of Search: 250/281, 250/282, 250/287
• US Class Current: 250/287
• CPC Class Codes: G01N 27/622 Ion mobility spectrometry

Abstract

Methods and apparatus for ion mobility spectrometry and analyte detection and identification verification system are disclosed. The apparatus is configured to be used in an ion mobility spectrometer and includes a plurality of reactant reservoirs configured to contain a plurality of reactants which can be reacted with the sample to form adducts having varying ion mobilities. A carrier fluid, such as air or nitrogen, is used to carry the sample into the spectrometer. The plurality of reactants are configured to be selectively added to the carrier stream by use inlet and outlet manifolds in communication with the reagent reservoirs, the reservoirs being selectively isolatable by valves. The invention further includes a spectrometer having the reagent system described. In the method, a first reactant is used with the sample. Following a positive result, a second reactant is used to determine whether a predicted response occurs. The occurrence of the second predicted response tends to verify the existence of a component of interest within the sample. A third reactant can also be used to provide further verification of the existence of a component of interest. A library can be established of known responses of compounds of interest with various reactants and the results of a specific multi-reactant survey of a sample can be compared against the library to determine whether a component detected in the sample is likely to be a specific component of interest.

Claims

1. An ion mobility spectrometer comprising:

a sample inlet system configured to receive a sample for introduction into a carrier fluid stream for transport of the sample within the spectrometer as a sample stream;

a sample vaporization and ionization system in fluid communication with the sample stream, configured to vaporize and ionize at least a part of the sample to produce analyte in an analyte stream;

a spectrometry analyzer positioned downstream of the sample vaporization and ionization system and in fluid communication with the analyte stream, the spectrometry analyzer producing signals in response to the chemical composition of the analyte;

a signal processor configured to process the signals produced by the spectrometry analyzer to produce an output signal indicative of the presence of identified substances;

a reagent system configured to introduce a plurality of reagents into the carrier fluid, the reagent system comprising;

a first reagent reservoir;

a second reagent reservoir;

a carrier fluid inlet manifold having a carrier fluid inlet connectable to a source of carrier fluid, and first and second carrier fluid outlets in respective fluid communication with the first and second reagent reservoirs, the carrier fluid inlet of the carrier fluid inlet manifold being in selective fluid communication with the first and second reagent reservoirs; and

an outlet manifold having first and second reagent outlets in respective fluid communication with the first and second reagent reservoirs, and a sample stream outlet configured to entrain a sample from the sample inlet system into the sample stream, the sample stream outlet being in selective fluid communication with the first and second reagent reservoirs;

wherein the selective fluid communication of the carrier fluid inlet, and the selective fluid communication of the first and second reagent reservoirs with the sample stream outlet, is achieved using valves; and

an identification verification system, comprising;

a selective signal detection circuit configured to identify a first signal from the signal processor having a potential to be a signal of interest, the first signal being generated when a first reagent from the reagent system is mixed with the sample stream, the selective signal detection circuit being further configured to identify a second signal from the signal processor, the second signal being generated when a second reagent from the reagent system is mixed with the sample stream; and

a reagent switching circuit configured to isolate the carrier fluid stream from the first reagent in the reagent system and connect the sample stream to a second reagent in the reagent system.

2. The ion mobility spectrometer of claim 1 wherein the valves comprise automatically operable solenoid valves.

3. The ion mobility spectrometer of claim 2 wherein in the reagent switching circuit is configured to isolate the sample stream from the first reagent in the reagent system and connect the sample stream to a second reagent in the reagent system in response to identification of the first signal by the signal detection circuit.

4. The ion mobility spectrometer of claim 3 further comprising a verification circuit configured to verify the probable presence of a specific component within the analyte based on the existence of the first and second signals.

5. The ion mobility spectrometer of claim 2 wherein the reagent switching circuit is configured to alternately isolate the sample stream from the first reagent in the reagent system and connect the sample stream to a second reagent in the reagent system, and isolate the sample stream from the second reagent in the reagent system and connect the sample stream to the first reagent in the reagent system.

6. The ion mobility spectrometer of claim 4 wherein:

the reagent system further comprises a third reagent reservoir in selective fluid communication with the sample stream outlet via a third reagent outlet;

the signal detection circuit is configured to identify a first anticipated response from the signal processor, the first anticipated response being generated when a third reagent from the reagent system is included in the sample stream; and

the verification circuit is configured to verify the presence of the specific component within the analyte based on the existence of the first and second signals in combination with one of the existence or absence of the first anticipated response.

7. The ion mobility spectrometer of claim 6 wherein the verification circuit further comprises a library of anticipated first and second signals and first responses which are correlated to at least one component which may be present in the analyte, and wherein the circuit is further configured to compare actual first and second signals and first responses against the library to identify the possible presence of the component in the analyte.

8. The ion mobility spectrometer of claim 6 wherein:

the reagent system further comprises a fourth reagent reservoir in selective fluid communication with the sample stream outlet via a third reagent outlet;

the signal detection circuit is configured to identify a second anticipated response from the signal processor, the second anticipated response being generated when a fourth reagent from the reagent system is included in the sample stream; and

the verification circuit is configured to verify the presence of the specific component within the analyte based on the existence of the first and second signals in combination with a predetermined combination of the existence or absence of the first anticipated response and the existence or absence of the second anticipated response.

9. The ion mobility spectrometer of claim 8 wherein:

the reagent system further comprises a fifth reagent reservoir in selective fluid communication with the sample stream outlet via a third reagent outlet;

the signal detection circuit is configured to identify a third anticipated response from the signal processor, the third anticipated response being generated when a fifth reagent from the reagent system is included in the sample stream; and

the verification circuit is configured to verify the presence of the specific component within the analyte based on the existence of the first and second signals in combination with a predetermined combination of the existence or absence of the first anticipated response, the existence or absence of the second anticipated response, and the existence or absence of the second anticipated response.

10. A spectrometer comprising:

a sample inlet system configured to introduce a sample into a carrier fluid stream for transport of the sample within the spectrometer as a sample stream;

a spectrometry analyzer positioned downstream of the inlet system and in fluid communication with the sample stream, the spectrometry analyzer producing signals in response to the chemical composition of components in the sample stream;

wherein a sample flow path is formed between the sample inlet system and the spectrometry analyzer, the spectrometer further comprising;

a signal processor configured to process the signals produced by the spectrometry analyzer to produce an output signal indicative of the presence of identified substances;

a reagent system configured to selectively introduce at least two reagents into the sample flow path, the reagent system comprising a first reagent reservoir and a second reagent reservoir in selective fluid communication with the sample flow path; and

a reagent switching circuit configured to control the selective fluid communication of the first reagent reservoir and the second reagent reservoir with the sample flow path in response to the output signal.