Abstract: This disclosure provides liquid chromatography tandem mass spectrometer (LC-MS/MS) methods and systems for detecting low levels of pesticides in a test sample. In the disclosed methods and systems, an ammonium salt is added to a mobile phase added to a liquid chromatography column or to the eluant from a liquid chromatography column. This addition improves the signal for certain pesticides by a factor of from 2 to 20, improving their detection limits in a variety of test samples.

Abstract: This disclosure provides liquid chromatography tandem mass spectrometer (LC-MS/MS) methods and systems for detecting low levels of pesticides and mycotoxins in a test sample. In the disclosed methods and systems, oxalic acid is added to a mobile phase composition of a reverse phase chromatographic separation column. This addition improves the signal for certain pesticides and mycotoxins by a factor of from 1.5 to 9, improving their detection limits in a variety of test samples.

Abstract: This disclosure provides quantitative, rapid, and reliable LC-MS/MS methods for analyzing panels of pesticides and mycotoxins in various samples, including very hydrophobic and chlorinated compounds normally analyzed on a GC-MS/MS system. The methods can be carried out using a single instrument and can detect and quantify levels of the pesticides and mycotoxins that are well below action limits specified by U.S. states (e.g., California) and other countries (e.g., Canada) for these compounds in cannabis products.

Abstract: This disclosure provides quantitative, rapid, and reliable LC-MS/MS methods for analyzing panels of pesticides and mycotoxins in various samples, including very hydrophobic and chlorinated compounds normally analyzed on a GC-MS/MS system. The methods can be carried out using a single instrument and can detect and quantify levels of the pesticides and mycotoxins that are well below action limits specified by U.S. states (e.g., California) and other countries (e.g., Canada) for these compounds in cannabis products.

Abstract: This disclosure provides quantitative, rapid, and reliable LC-MS/MS methods for analyzing panels of pesticides and mycotoxins in various samples, including very hydrophobic and chlorinated compounds normally analyzed on a GC-MS/MS system. The methods can be carried out using a single instrument and can detect and quantify levels of the pesticides and mycotoxins that are well below action limits specified by U.S. states (e.g., California) and other countries (e.g., Canada) for these compounds in cannabis products.

Abstract: A gas chromatography system comprising a sample introduction device, an oven coupled to the sample introduction device and a detector coupled to the oven is disclosed. In certain examples, the oven may be configured to receive a chromatography column in a space in the oven. In some examples, the oven may be constructed and arranged to provide a substantially constant temperature to the space during an analysis stage of the gas chromatography system.

Abstract: Certain aspects and examples are directed to sorbent devices and methods of using them. In certain embodiments, a sorbent device comprising a body comprising a sampling inlet, a base and a longitudinal diffusion path between the inlet and the base is provided. In some embodiments, the sorbent device can include at least two sorbent materials fluidically coupled to the longitudinal diffusion path, in which the sorbent materials are arranged from a material with a weakest sorbent strength to a material with a strongest sorbent strength with the weakest sorbent strength material adjacent to the sampling inlet.

Abstract: A gas chromatography system comprising a sample introduction device, an oven coupled to the sample introduction device and a detector coupled to the oven is disclosed. In certain examples, the oven may be configured to receive a chromatography column in a space in the oven. In some examples, the oven may be constructed and arranged to provide a substantially constant temperature to the space during an analysis stage of the gas chromatography system.

Abstract: A gas chromatography system comprising a sample introduction device, an oven coupled to the sample introduction device and a detector coupled to the oven is disclosed. In certain examples, the oven may be configured to receive a chromatography column in a space in the oven. In some examples, the oven may be constructed and arranged to provide a substantially constant temperature to the space during an analysis stage of the gas chromatography system.

Abstract: The invention relates to an electrochemical sensor and method for providing the sensor having an insulator, an electrode deposited on the insulator, an electrolytic material in contact with the electrode for providing an electrical connection, and a cooling and heating element in contact with the insulator and spaced apart from the electrode for adjusting a temperature of the sensor.

Abstract: The present teachings relate to systems and methods for oxidizing a sensor having a substrate, an electrode in contact with the substrate, and an electrolytic material in contact with the electrode, where oxidizing includes applying an oxidizing potential (between approximately 350 mV and 700 mV) to the electrode. In some embodiments, the methods and systems include hydrating the sensor by applying a hydrating potential (between approximately 0 mV and ?500 mV) to the electrode. In some embodiments, the applied potential can vary cyclically between an oxidizing and hydrating potential.

Abstract: The invention relates to an electrochemical gas sensor having both a reference sensor and an active sensor, whereby each reference and active sensor includes a substrate, a counter electrode deposited on a surface of the substrate, a sensing electrode also deposited on the surface, and a solid electrolytic material in electrical contact with both electrodes for carrying a flow of ions between them, which measures a concentration of a gas and compensates for relative humidity differences between sample gas and surrounding atmosphere. The sensor also includes a layer of solid electrolytic material on the sensing electrode of the reference sensor and a film of solid electrolytic material on the sensing electrode of the active sensor, whereby the layer is thicker than the film. The invention may further include a reference electrode in both the reference and active sensors for improving sensor accuracy and/or repeatability.

Abstract: Certain aspects and examples are directed to sorbent devices and methods of using them. In certain embodiments, a sorbent device comprising a body comprising a sampling inlet, a base and a longitudinal diffusion path between the inlet and the base is provided. In some embodiments, the sorbent device can include at least two sorbent materials fluidically coupled to the longitudinal diffusion path, in which the sorbent materials are arranged from a material with a weakest sorbent strength to a material with a strongest sorbent strength with the weakest sorbent strength material adjacent to the sampling inlet.

Abstract: The invention relates to an electrochemical gas sensor having a substrate, substrate surface for depositing electrodes thereon, counter and sensing electrodes for measuring current flow, an electrolyte for providing an electrical connection between the electrodes, and an electrode surface having minimal porosity, pore size, and thickness for deterring flooding.

Abstract: The invention relates to a method and apparatus for providing a reactor having a heater, a passage for transporting a reactant, and a chamber containing a gas sample and being coupled to the passage for receiving the reactant and mixing the reactant with the gas sample. The reactor further includes a connector leading from the chamber to the heater for transporting a mixture of the reactant and gas sample, and wherein the heater heats the mixture of the reactant and gas sample.

Abstract: The invention relates to an electrochemical gas generator including a substrate for providing a surface for electrode deposition, a first electrode deposited on the surface for providing an electrical connection with a conducting medium, a second electrode deposited on the substrate for generating a gas, and a plurality of members extending from at least one side of the first electrode placed alternately with a plurality of extensions protruding from at least one side of the second electrode for improving generator efficiency.

Abstract: The invention relates to a method and apparatus for determining a concentration of a component in an unknown mixture. The method includes the steps of preparing a reactant having a specified pH level and a specified temperature and combining the unknown mixture with the reactant. The method further includes varying the pH level and temperature of the combination of the reactant and the unknown mixture to facilitate converting at least one selected component. Upon varying the pH level and temperature, the method will release volatiles from the selected component(s). Based on these released volatiles, which indicate the concentration of the selected component(s), the method detects the indication. The apparatus for determining a concentration of a component in an unknown mixture includes a container having a specified volume, a reactant chamber, and a sample chamber. The receptacle contains a reactant, placed within the reactant chamber, having a predetermined pH level and a predetermined volume.

Abstract: The invention relates to an electrochemical gas sensor having improved response time and sensitivity. The electrochemical gas sensor includes a substrate for providing a surface upon which a film of conductive material may be deposited, a pair of electrodes deposited on the substrate for permitting a measurement of current, and an electrolytic material for providing an electrical connection between the electrodes. The electrochemical gas sensor further includes a passage in the surface for holding or transporting gas received from a gas source, whereby sensing occurs at a three way interface where the gas, electrolytic material, and electrodes come in direct contact with one another.

Abstract: A miniaturized gas sensor comprised of film type electrodes, on a non-conductive supportive substrate, and in contact with a dry ionomer electrolyte, for detection of toxic gases, i.e., carbon monoxide, and other oxidizable or reducible gases and vapors and method of making same is described. The all-solid planar sensor cell has two or more film type electrodes arranged on a non-conductive planar surface of a supportive substrate. Manufacturing the electrochemical sensor with dry ionomer prevents electrode flooding and allows for improved response time upon assembly. The sensor cell contains no liquid electrolyte and is operated in a constant-voltage, potentiostatic or potentiodynamic mode. A high sensitivity to a select gas or vapor is achieved by a three-phase contact area design for a sensing electrode, which provides contact with the solid ionomer electrolyte, as well as the gas sample via diffusion openings or holes that penetrate through the supportive substrate.

Abstract: The invention relates to a method and apparatus for providing a reactor having a heater, a passage for transporting a reactant, and a chamber containing a gas sample and being coupled to the passage for receiving the reactant and mixing the reactant with the gas sample. The reactor further includes a connector leading from the chamber to the heater for transporting a mixture of the reactant and gas sample, and wherein the heater heats the mixture of the reactant and gas sample.