Abstract: An ion mobility spectrometer includes a drift tube, a plurality of sensors arranged at one end of the drift tube that provide signals corresponding to ions impinging on the sensors, and a multi-channel data acquisition system, coupled to each of the sensors, that compensates for delays experienced by ions that are farther from a main axis of drift tube prior to combining the signals from the sensors. The sensors may be electrically biased so that a particular one of the sensors that attracts ions is adjacent to one or more of the sensors that do not attract ions. Signals from adjacent sensors may be subtracted to reduce signal values corresponding to mirror current. The plurality of sensors may be arranged as a honeycomb or as a plurality of concentric circles.

Abstract: A tandem instrument using a variable frequency pulsed ionization source and two separation techniques, low (IMS) and high (FAIMS) field mobility is provided. The analytical stage features a field driven FAIMS cell embedded on-axis within the IMS drift tube. The FAIMS cell includes two parallel grids of approximately the same diameter as the IMS rings and can be placed anywhere along the drift tube and biased according to their location in the voltage divider ladder to create the same IMS field. The spacing between the grids constitutes the analytical gap where ions are subject, in addition to the drift field, to the asymmetric dispersive field of the FAIMS. The oscillatory motion performed during the high and low voltages of the asymmetric waveform separates the ions according to the difference in their mobilities.

Abstract: For ion mobility spectrometry applications, a desired shape of a sensor structure may be created by forming a desired shape from a ceramic material, such as aluminum nitride. In various embodiments, the sensor structure may be formed using discrete individual ceramic sheets and/or from a preformed ceramic tube. Via holes are formed into the sensor structure to provide for efficient circuitry configurations of the IMS drift tube and/or providing electrical connections between the interior and exterior of the drift tube.

Abstract: Devices and techniques for ion analysis, including ion mobility separation and mass spectrometry, are provided using a dual polarity spark ion source and having the flexibility required to optimize the detection performance for a broad range of illicit substances with different physical and chemical properties. In various embodiments, the volatility and electro-chemical aspects may be addressed by the system described herein by performing real-time detection of compounds detectable in both positive and negative polarities and/or prioritizing spectra acquisition in a given polarity due to the high volatility and therefore short residence of certain target compounds.

Abstract: For ion mobility spectrometry applications, a desired shape of a sensor structure may be created by forming a desired shape from a ceramic material, such as aluminum nitride. In various embodiments, the sensor structure may be formed using discrete individual ceramic sheets and/or from a preformed ceramic tube. Via holes are formed into the sensor structure to provide for efficient circuitry configurations of the IMS drift tube and/or providing electrical connections between the interior and exterior of the drift tube.

Abstract: An air drying system includes a first air dryer that receives ambient air and provides as output exceptionally dry air having a moisture concentration of approximately 16 ppm or below, a second air dryer that receives ambient air and provides as output exceptionally dry air having a moisture concentration of approximately 16 ppm or below, and a valve coupled to and selectively switching between output from the air dryers to provide exceptionally dry air, where one of the first and second air dryers is automatically regenerated while the valve switches to provide exceptionally dry air from an other one of the first and second air dryers. The air dryers may remove moisture from ambient air by cooling the ambient air to approximately ?57° C. Each of the air dryers may include a heat sink section, a cooling section (possibly with cooling elements), and an air flow section.

Abstract: Using combined orthogonal techniques, such as low (IMS) and high (FAIMS) field mobility techniques, offers several advantages to ion detection and analysis techniques including low cost, no vacuum required, and the generation of 2-D spectra for enhanced detection and identification. Two analytical devices may be operated in different modes, which results in overall flexibility by adapting the hyphenated instrument to the application's requirements. With the IMS-FAIMS hardware level flexibility, the instruments may be configured and optimized to exploit different trade-offs suitable for a variety of detection scenarios of for different lists of target compounds.

Abstract: Selective ionization at atmospheric or near atmospheric pressure of a sample diluted in air is provided in multiple steps. Initially, components of air and/or other gas are ionized to generate reactive ions. The reactive ions are then filtered using a high frequency filter to yield selected reactive ions. Thereafter, the selected reactive ions are reacted with sample molecules of a sample being analyzed in a charge transfer process. Depending on the properties of the sample molecules, the filter may select some reactive ions to enter the sample zone and block others entirely thus controlling ion chemistry and charge transfer yields in the sample zone. The described system is directed to controlling ions at the ion source level, using a high frequency filter technique, in connection with subsequent analysis. The method generates the ions of choice for subsequent analysis in such platforms as ion mobility and differential mobility spectrometers.

Abstract: A system and method for producing a continuous or pulsed source of high energy electrons at or near atmospheric pressure is disclosed. High energy electrons are used to ionize analyte molecules in ambient air through collisions with reactant ions. The device includes an electron emitter, electron optics, and a thin membrane in an evacuated tube. The electron emitter may include a photocathode surface mounted on an optically transparent window and an external source of UV photons. The transparent window may include a UV transparent window mounted on an evacuated tube and/or the evacuated tube may be a transparent tube on which a photocathode surface film is deposited. The electron optics may include successive electrodes biased at increasing voltages. The membrane may include a material transparent or semi-transparent to energetic electrons. Upon impacting the membrane, continuous or pulsed electron packets are partially transmitted through to a high pressure ionization region.

Abstract: Devices and techniques for ion analysis, including ion mobility separation and mass spectrometry, are provided using a dual polarity spark ion source and having the flexibility required to optimize the detection performance for a broad range of illicit substances with different physical and chemical properties. In various embodiments, the volatility and electro-chemical aspects may be addressed by the system described herein by performing real-time detection of compounds detectable in both positive and negative polarities and/or prioritizing spectra acquisition in a given polarity due to the high volatility and therefore short residence of certain target compounds.

Abstract: For ion mobility spectrometry applications, a desired shape of a sensor structure may be created by forming a desired shape from a ceramic material, such as aluminum nitride. In various embodiments, the sensor structure may be formed using discrete individual ceramic sheets and/or from a preformed ceramic tube. Via holes are formed into the sensor structure to provide for efficient circuitry configurations of the IMS drift tube and/or providing electrical connections between the interior and exterior of the drift tube.

Abstract: A system and method for producing a continuous or pulsed source of high energy electrons at or near atmospheric pressure is disclosed. High energy electrons are used to ionize analyte molecules in ambient air through collisions with reactant ions. The device includes an electron emitter, electron optics, and a thin membrane in an evacuated tube. The electron emitter may include a photocathode surface mounted on an optically transparent window and an external source of UV photons. The transparent window may include a UV transparent window mounted on an evacuated tube and/or the evacuated tube may be a transparent tube on which a photocathode surface film is deposited. The electron optics may include successive electrodes biased at increasing voltages. The membrane may include a material transparent or semi-transparent to energetic electrons. Upon impacting the membrane, continuous or pulsed electron packets are partially transmitted through to a high pressure ionization region.

Abstract: Selective ionization at atmospheric or near atmospheric pressure of a sample diluted in air is provided in multiple steps. Initially, components of air and/or other gas are ionized to generate reactive ions. The reactive ions are then filtered using a high frequency filter to yield selected reactive ions. Thereafter, the selected reactive ions are reacted with sample molecules of a sample being analyzed in a charge transfer process. Depending on the properties of the sample molecules, the filter may select some reactive ions to enter the sample zone and block others entirely thus controlling ion chemistry and charge transfer yields in the sample zone. The described system is directed to controlling ions at the ion source level, using a high frequency filter technique, in connection with subsequent analysis. The method generates the ions of choice for subsequent analysis in such platforms as ion mobility and differential mobility spectrometers.

Abstract: A tandem instrument using a variable frequency pulsed ionization source and two separation techniques, low (IMS) and high (FAIMS) field mobility is provided. The analytical stage features a field driven FAIMS cell embedded on-axis within the IMS drift tube. The FAIMS cell includes two parallel grids of approximately the same diameter as the IMS rings and can be placed anywhere along the drift tube and biased according to their location in the voltage divider ladder to create the same IMS field. The spacing between the grids constitutes the analytical gap where ions are subject, in addition to the drift field, to the asymmetric dispersive field of the FAIMS. The oscillatory motion performed during the high and low voltages of the asymmetric waveform separates the ions according to the difference in their mobilities.

Abstract: Using combined orthogonal techniques, such as low (IMS) and high (FAIMS) field mobility techniques, offers several advantages to ion detection and analysis techniques including low cost, no vacuum required, and the generation of 2-D spectra for enhanced detection and identification. Two analytical devices may be operated in different modes, which results in overall flexibility by adapting the hyphenated instrument to the application's requirements. With the IMS-FAIMS hardware level flexibility, the instruments may be configured and optimized to exploit different trade-offs suitable for a variety of detection scenarios of for different lists of target compounds.