Abstract: A method for providing in situ chemical transformation and ionization of a portion (e.g., inorganic oxidizer) of a sample via an analyte detection system is disclosed herein. The method includes introducing a gas into an ionization source of the analyte detection system via an inlet. The method further includes generating ions within the ionization source and directing the gas and generated ions through and out of the ionization source and to the sample. The sample is located proximal to the ionization source in an ambient environment. The ions chemically react with the sample and desorb and ionize an analyte from the sample, the analyte being generated from the inorganic oxidizer, the desorbed analyte having a lower melting point and/or better desorption kinetics than the inorganic oxidizer. The method further includes receiving the desorbed analyte via an analyzer of the analyte detection system.

Abstract: A trace analyte collection swab having a collection surface at least partially coated with a microscopically tacky substance to enhance pick-up efficiency is described. In embodiments, the trace analyte collection swab comprises a substrate including a surface having a trace analyte collection area and a coating disposed on the surface of the substrate in the trace analyte collection area. The coating is configured to be microscopically adhesive to collect particles of the trace analyte from a surface when the trace analyte collection area is placed against the surface. In one embodiment, the coating comprises Polyisobutylene.

Abstract: The present disclosure relates to an ion exchange process, as well as a process and system for detecting nitrates, which employ a class of dopants comprising at least two functional groups capable of simultaneous convergent hydrogen bonding with a nitrate ion.

Abstract: Systems and methods disclosed provide for methods of managing polarity switching in an ion mobility spectrometer, and provide for management of the repelling grid voltage, the gating grid voltage, and the fixed grid voltage during polarity switching. Systems and methods also provide for the management of the effect of dielectric relaxation in an insulator proximal to the collector, and provide for a preamplifier coupled to the collector including a switch, and a method of managing the collector output including the switch. Systems and methods consistent with the current disclosure further provide for a method of normalizing ion mobility data by determining fitting coefficients associated with a plurality of measurement data sets, and subtracting the curves determined by the fitting coefficients from the data acquired by the ion mobility spectrometer.

Abstract: Method and systems for managing clear-down are provided. The method can include generating a clear-down trigger associated with an ion mobility spectrometer and operating the ion mobility spectrometer in fast clear-down mode in response to the clear-down trigger. Methods and systems can further provide that where the ion mobility spectrometer operates in fast-switching mode, the ion mobility spectrometer alternating a plurality of times between operation according to a positive ion mode and operation according to a negative ion mode, and further operating according to the positive ion mode for less than about 1 second before switching to the operation according to the negative ion mode, and operating according to the negative ion mode for less than about 1 second before switching to the operation according to the positive ion mode.

Abstract: Method and systems for monitoring ion mobility spectrometers are provided. The method can include acquiring scan data, and generating a segment data set from the scan data. The method can further include deriving a subset of peak data from the segment data, where the subset of peak data has an associated set of peak metrics, and deriving a value from the subset of peak data associated with a criteria element of the associated set of peak metrics, where the criteria element has an associated range of values. The method can further include providing an indication in the event the value lies outside the associated range of values.

Abstract: An ion detection assembly is described that includes a drift chamber, an inlet assembly, and a collector assembly. The drift chamber is formed of substantially non-conductive material and/or semi-conductive material. A patterned resistive trace is deposited on one or more of an interior surface or an exterior surface of the drift chamber. The patterned resistive trace is configured to connect to a source of electrical energy. The inlet assembly and the collector assembly are in fluid communication with the drift chamber. The inlet assembly includes an inlet for receiving a sample, a reaction region for ionizing the sample, and a gate for controlling entrance of the ionized sample to the drift chamber. The collector assembly includes a collector plate for collecting the ionized sample after the ionized sample passes through the drift chamber.

Abstract: An ion mobility spectrometer analytical instrument, including an ion mobility spectrometer, a swab interface, and a desorber assembly. The desorber assembly includes a heat transfer device configured to heat a desorber, as well as a supply configured to direct gas through the desorber. The instrument further includes a drift tube, high voltage device arrayed, at least in part, proximate to the drift tube, wherein the high voltage device is configured to change a polarity of a voltage applied to the drift tube and have an absolute voltage of about 500 to 1500 volts. The instrument further includes a reactant supply unit adapted to supply reactant during a sample substance analysis, and a control unit.

Abstract: An ion mobility spectrometer analytical instrument, including an ion mobility spectrometer, a swab interface, and a desorber assembly. The desorber assembly includes a heat transfer device configured to heat a desorber, as well as a supply configured to direct gas through the desorber. The instrument further includes a drift tube, high voltage device arrayed, at least in part, proximate to the drift tube, wherein the high voltage device is configured to change a polarity of a voltage applied to the drift tube and have an absolute voltage of about 500 to 1500 volts. The instrument further includes a reactant supply unit adapted to supply reactant during a sample substance analysis, and a control unit.

Abstract: A concentric APCI surface ionization probe, supersonic sampling tube, and method for use of the concentric APCI surface ionization probe and supersonic sampling tube are described. In an embodiment, the concentric APCI surface ionization probe includes an outer tube, an inner capillary, and a voltage source coupled to the outer tube and the inner capillary. The inner capillary is housed within and concentric with the outer tube such that ionized gas (e.g., air) travels out of the outer tube, reacts with a sample, and the resulting analyte ions are sucked into the inner capillary. A supersonic sampling tube can include a tube coupled to a mass spectrometer and/or concentric APCI surface ionization probe, where the tube includes at least one de Laval nozzle.

Abstract: A corona ionization source assembly and fabrication methods are described that include a fine wire including a wire core including a first material, and a wire coating including a second material, where the wire coating surrounds a portion of the wire core, and the diameter of the wire coating is greater than the diameter of the wire core. Additionally, the fine wire may be coupled to a mounting post. In an implementation, a process for fabricating the corona ionization source assembly that employs the techniques of the present disclosure includes forming a wire core, forming a wire coating that surrounds the wire core, forming a mask layer on at least a portion of the wire coating, etching the wire coating, and removing the mask layer from the wire coating.

Abstract: An ionization device includes a first electrode comprising a conductive member coated with a dielectric layer. The ionization device also includes a spine extending adjacent to and at least partially along the first electrode. The ionization device further includes a second electrode comprising conductive segments disposed adjacent the first electrode. Each one of the conductive segments contacts the spine at a respective contact location. The dielectric layer of the first electrode separates the conductive member of the first electrode from the spine and the second electrode. The ionization device is configured to create plasma generating locations corresponding to respective crossings of the first electrode and the second electrode.

Abstract: A concentric APCI surface ionization probe, supersonic sampling tube, and method for use of the concentric APCI surface ionization probe and supersonic sampling tube are described. In an embodiment, the concentric APCI surface ionization probe includes an outer tube, an inner capillary, and a voltage source coupled to the outer tube and the inner capillary. The inner capillary is housed within and concentric with the outer tube such that ionized gas (e.g., air) travels out of the outer tube, reacts with a sample, and the resulting analyte ions are sucked into the inner capillary. A supersonic sampling tube can include a tube coupled to a mass spectrometer and/or concentric APCI surface ionization probe, where the tube includes at least one de Laval nozzle.

Abstract: Systems and methods disclosed provide for methods of managing polarity switching in an ion mobility spectrometer, and provide for management of the repelling grid voltage, the gating grid voltage, and the fixed grid voltage during polarity switching. Systems and methods also provide for the management of the effect of dielectric relaxation in an insulator proximal to the collector, and provide for a preamplifier coupled to the collector including a switch, and a method of managing the collector output including the switch. Systems and methods consistent with the current disclosure further provide for a method of normalizing ion mobility data by determining fitting coefficients associated with a plurality of measurement data sets, and subtracting the curves determined by the fitting coefficients from the data acquired by the ion mobility spectrometer.

Abstract: A cartridge assembly includes a body portion (14), that is thermally and electrically non-conductive, defining an opening (28), a bus bar (18) coupled to the body portion, the bus bar being thermally and electrically conductive, and a clamping bar (20), including a scalloped surface configured to oppose the bus bar, the clamping bar being thermally and electrically conductive. At least one of the bus bar and the clamping bar is biased toward the other of the bus bar and the clamping bar.

Abstract: Systems and methods disclosed provide for methods of managing polarity switching in an ion mobility spectrometer, and provide for management of the repelling grid voltage, the gating grid voltage, and the fixed grid voltage during polarity switching. Systems and methods also provide for the management of the effect of dielectric relaxation in an insulator proximal to the collector, and provide for a preamplifier coupled to the collector including a switch, and a method of managing the collector output including the switch. Systems and methods consistent with the current disclosure further provide for a method of normalizing ion mobility data by determining fitting coefficients associated with a plurality of measurement data sets, and subtracting the curves determined by the fitting coefficients from the data acquired by the ion mobility spectrometer.

Abstract: A surface ionization source comprises a tube having a first end, a second end, and an interior bore extending through the tube from the first end to the second end. The first end of the tube is configured to receive a flow of gas and the second end of the tube is configured to direct the flow of gas onto a surface configured to hold an analyte. A radioactive source is at least substantially disposed in the interior bore of the tube. The radioactive source is configured to form ions in the flow of gas as the flow of gas passes through the interior bore. The flow of gas containing the ions is directed onto the analyte to at least partially ionize the analyte.

Abstract: A sample introduction system configured for introducing analytes of a solid phase micro extraction (SPME) sample into an analytical instrument system (e.g., mass spectrometer) is described. The sample introduction system includes a pressure vessel configured with an inlet port via which a probe portion (e.g., SPME fiber) of a SPME assembly is received into a sealed volume of the pressure vessel. The probe portion of the SPME assembly is coated with an extracting phase material, the analytes being absorbed into and/or adsorbed onto the extracting phase material. The pressure vessel is configured for providing an environment in which desorption of the analytes from the extracting phase material occurs at a gaseous pressure which is substantially less than atmospheric pressure (e.g., less than 100 mTorr). The desorbed analytes are then directed to the vacuum chamber of the analytical instrument system via an outlet port of the pressure vessel.

Abstract: A mass spectrometry system for screening a sample for one or more analytes includes a pre-mass spectrometry screening apparatus configured to pre-screen an ionized sample to generate output correlated to the composition of the sample, and a mass spectrometer. A sample gate is opened to allow flow of at least a portion of the ionized sample to the mass spectrometer and closed to prevent flow of the ionized sample to the mass spectrometer. A processing system compares results of the pre-mass spectrometry screening to an analyte database, wherein correlation of the results to an analyte within the analyte database comprises a preliminary positive identification. When the processing system determines that a preliminary positive identification is made, it causes the gate to open for a period of time. However, when the processing system determines that a preliminary positive identification is not made, it causes the gate to remain closed.

Abstract: Looped ionization sources for ion mobility spectrometers are described. The ionization sources can be used to ionize molecules from a sample of interest in order to identify the molecules based on the ions. In an implementation, an electrical ionization source includes a wire that is looped between electrical contacts. The wire is used to form a corona responsive to application of voltage between the wire and the walls of an ionization chamber. The corona can form when a sufficient voltage is applied between the wire and the walls. A difference in electrical potential between the wire and a wall forming an ionization chamber, in which wire is contained, can be used to draw the ions away from the wire. In embodiments, the wire can be heated to reduce the voltage used to strike the corona. The ions, subsequently, may ionize the molecules from the sample of interest. The looped corona source can also be used in mass spectrometers (MS).