Sensitivity traps for electronic trace detection having explosives or narcotics embedded in a plasticized polymer matrix
Inventors
Verkerk, Udo H. • Romanov, Vladimir • Schmidt, Hartwig • Lukow, Stefan • Macrae, Robert • Andersen, Zachary
Assignees
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Publication Number
US-12411122-B2
Publication Date
2025-09-09
Expiration Date
Abstract
Embodiments of the present specification provide methods and systems for sensitivity traps that contain a polymer matrix made from an inert polymer material for encapsulation of trace amounts of explosives and narcotics and a suitable plasticizer material, the types and ratios of which may be selected based on type of analyte that is to be used with the sensitivity trap. The plasticizer material functions by breaking up intra and inter-molecular polymer chain interactions resulting in a larger diffusion coefficient of the analyte within the polymer matrix. Therefore, in embodiments, sufficient amounts of plasticizers are added to the sensitivity trap, which also reduces a glass transition temperature of the polymer matrix and the trap.
Core Innovation
The invention relates to sensitivity traps for electronic trace detectors in which at least one analyte is embedded within a polymer matrix. The sensitivity trap is defined by a target glass transition temperature and is configured to provide a desorption profile during ion mobility spectrometer (IMS) operation. A plasticizer is used to set the polymer glass transition temperature and to influence the analyte diffusion coefficient so that the analyte is released from the mixture with sufficient desorption intensity.
The amount and type of plasticizer are selected based on a type of the at least one analyte and on at least one of the target glass transition temperature or a diffusion coefficient of the at least one analyte. When inserted into an ion mobility spectrometer (IMS) and exposed to a heating rate of approximately 33° C. per second, the analyte is released with sufficient desorption intensity to reach at least 2000 a.u. as measured by the IMS within 4 seconds of the onset of heating. Documented embodiments describe plasticized versus non-plasticized materials yielding a sharper, more defined onset and release behavior.
The invention also includes a method of manufacturing the sensitivity trap by selecting and incorporating the plasticizer, dissolving a polymer and the selected plasticizer in a solvent to form a mixture, adding the at least one analyte, removing the solvent, and depositing the mixture onto a carrier to form the sensitivity trap. Carrier materials are described as inert carrier material classes, and the composite is characterized as a solvent-cast membrane or deposited sensitivity trap structure. Documented embodiments describe low analyte mass in the polymer matrix and improved shelf life and humidity/temperature resistance.
Claims Coverage
The document includes two independent claims, each defining a sensitivity trap/measurement performance standard in an ion mobility spectrometer (IMS) and tying that performance to selecting a plasticizer based on target glass transition temperature and analyte diffusion behavior. Each independent claim defines the core structural or manufacturing elements needed to achieve a desorption intensity of at least 2000 a.u. within 4 seconds under a heating rate of approximately 33° C. per second.
Plasticizer selection to meet IMS desorption intensity timing
Selecting an amount and a type of the plasticizer based upon a type of the at least one analyte and at least one of the target glass transition temperature or a diffusion coefficient of the at least one analyte, wherein the amount of plasticizer increases a diffusion coefficient of the at least one analyte such that, when inserted into an ion mobility spectrometer (IMS) and exposed to a heating rate of approximately 33° C. per second, the at least one analyte is released with sufficient desorption intensity to reach at least 2000 a.u. as measured by the IMS within 4 seconds of initiating/onset of heating.
Manufacturing a sensitivity trap by solvent mixture deposition onto a carrier
Dissolving a polymer and the selected amount and type of plasticizer in a solvent to form a mixture; adding the at least one analyte to the mixture; removing the solvent from the mixture; and depositing the mixture onto a carrier to form the sensitivity trap.
Polymer matrix with embedded analyte and plasticizer on a carrier
A sensitivity trap defined by a target glass transition temperature comprising a polymer matrix made of a polymer material; at least one analyte embedded within the polymer matrix; a plasticizer with an amount and type based upon the target glass transition temperature and a type of the at least one analyte, sufficient to increase a diffusion coefficient such that, in an IMS at approximately 33° C. per second, the at least one analyte is released with sufficient desorption intensity to reach at least 2000 a.u. within 4 seconds of the onset of heating; and a carrier material upon which the polymer matrix, at least one analyte, and plasticizer are deposited.
Across the two independent claims, the core inventive concept is configuring a polymer matrix sensitivity trap using a selected plasticizer amount and type, based on target glass transition temperature and analyte diffusion behavior, so that IMS heating at approximately 33° C. per second releases an embedded analyte with sufficient desorption intensity to reach at least 2000 a.u. within 4 seconds, with one claim further requiring a solvent-based manufacturing and deposition sequence.
Stated Advantages
Improved shelf life at least six months (stored up to 45° C.).
Improved humidity/temperature resistance.
Reduced analyte mass in comparison to non-plasticized configurations.
A sharp, adjustable thermal desorption profile during ETD operation with reduced analyte mass.
Improved desorption performance, including more rapid, defined onset and release behavior.
Documented Applications
Use of the sensitivity trap in electronic trace detectors, including operation in an ion mobility spectrometer (IMS) and IMS-type detectors.
Use of the sensitivity trap in electronic trace detector (ETD) operation, including thermal desorption profile generation during IMS operation.
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