Abstract: Examples of gas liquid separators include a chamber, a fluid mixture inlet, a gas outlet and a liquid outlet. The fluid mixture inlet and the gas and liquid outlets are in fluid communication with the chamber. A fluid mixture received at the fluid mixture inlet diffuses inside the chamber and is separated into a liquid and a gas. The separated liquid is gravity-fed to the liquid outlet. The gas liquid separators have reduced dispersion and increased liquid recovery in comparison to conventional gas liquid separators used for chromatographic separations. The reduced dispersion yields an improvement in the shape of chromatographic peaks.

Abstract: Exemplary embodiments are directed to a gas liquid separator that includes a chamber for receiving a fluid mixture, a fluid mixture inlet, a solvent outlet, and a gas outlet. The gas liquid separator can include a sensor disposed around or within the chamber for sensing at least one of a solvent level or a gas level. The gas liquid separator can include a regulator connected to at least one of the solvent outlet or the gas outlet for regulating at least one of the solvent level or the gas level within the chamber. Exemplary methods of regulating at least one of the solvent level or the gas level within a gas liquid separator of a CO2-based chromatography flow system are also provided.

Abstract: Exemplary embodiments of the present disclosure are directed to manipulating pressure-related hysteresis in a pressurized flow system by setting the pressure of the system to a predetermined location in the hysteresis band to advantageously minimize an effect of the pressure related hysteresis on the pressure of the system or to advantageously benefit from the effects of the hysteresis on the pressure of the system.

Abstract: A method for controlling fluid flowing through a chromatographic system includes determining a fluidic parameter related to density at a first fluidic location in the chromatographic system; and in response to the determined fluidic parameter, modifying a volumetric flow rate or a pressure at a second fluidic location in the chromatographic system to produce a selected mass flow rate of the fluid.

Abstract: A heater assembly used in chromatography includes a thermally conductive base having a chamber extending fully through the base with an opening at a first side of the base and at a second side of the base, and a cavity with an opening at the second side of the base. A heater is disposed within the cavity in thermal communication with the base. A thermistor assembly, having a thermistor within a thermally conductive body is disposed within the chamber. The body has a head region with a planar surface. The planar surface of the head region is exposed at the opening of the chamber at the first side of the base for making thermally conductive contact therewith. The thermistor assembly is thermally isolated from the base.

Abstract: A fluidic block has a thermally conductive body with a first end and a second end opposite the first end. The body has a cutout portion formed therein between the first and second ends. The cutout portion partitions the body into a first region, a second region, and a thin region between the first and second regions. The cutout portion produces a thermal break between the first and second regions. The thermal break operates to guide a heat flow between the first and second regions through the thin region. A thermally conductive chromatography tube extends through the first, second, and thin regions from the first end to the second end of the body. The tube is in thermal communication with the body. A section of the tube may run in a transverse direction across the body in the thin region of the body.

Abstract: Exemplary embodiments are directed to devices, methods and systems capable of pressurization, generally involving a flow system that includes a pressurized reservoir, at least one pump including a pump control valve, an outlet port, a shut-off valve and a vent valve. The flow system is configured to be pressurized. The shut-off valve is disposed between the pressurized reservoir and the at least one pump. The vent valve is disposed between the at least one pump and the outlet port. The shut-off valve, the vent valve and the pump control valve of the at least one pump are configured to actuate in a coordinated manner to control a pressurization of the flow system. Exemplary embodiments are further directed to devices, methods and systems for column switching, generally including at least a first column, a second column and a column switching valve.

Abstract: Exemplary embodiments are directed to vent valves, systems and methods generally involving a valve body that includes a seat retainer, a needle and a seat. The seat includes a bore extending there through and the needle includes a needle stem and a needle head. The seat is disposed inside the seat retainer. The needle stem is disposed inside the bore. The needle is configured to be pulled through the seat to stop flow through the bore. Exemplary embodiments are further directed to a system including a stem return spring mechanism and a solenoid return spring mechanism. A processing device is configured to actuate the solenoid return spring mechanism to permit the stem return spring mechanism to pull the needle through the seat to stop flow through the bore.

Abstract: A supercritical fluid chromatography system is provided with an injection valve subsystem for introducing a sample into a flow of mobile phase fluid. The injection valve subsystem includes an auxiliary valve and an inject valve. The operations of the auxiliary and inject valves are coordinated in such a manner as to reduce sample carry-over and system pressure perturbations occurring during sample injection.

Abstract: Systems and methods for operating a stepper motor of a pump at a desired low velocity include memory for storing information corresponding to an intake velocity profile. The intake velocity profile represents an optimized acceleration curve for operating the stepper motor over a range of motor velocities during an intake cycle. A processor of a system controller dynamically accesses the memory during the intake cycle to acquire the information representing the intake velocity profile and issues a series of pulses to the stepper motor based on this information. In response to the pulses, the stepper motor accelerates in accordance with the optimized acceleration curve represented by the intake velocity profile. The optimized acceleration curve is based on the available torque of the stepper motor across a range of motor velocities and enables the motor to operate with greater torque utilization and less margin than traditional linear acceleration profiles.

Abstract: The invention provides compression fittings and methods of assembling compression fittings. In exemplary embodiments, compression fittings are provided that include a fitting body, a ferrule and a tube. For example, the fitting body can be removably coupled to the ferrule when the tube is disposed therethrough.

Abstract: Methods, systems and apparatus are provided for degassing a supersaturated solution. An example degasser is described having a continuous body of gas-permeable tubing to remove an amount of a gas from the supersaturated solution below the gas's saturation point in the supersaturated solution. The degasser can be connected to at least one of a fraction collector or a detector. The example degasser is sized and/or positioned to cause a change in pressure (?P) across the degasser to drive removal of a dissolved gas from a supersaturated solution passing through the degasser. As a result of the reduction of gas, efficiencies in system flow and fraction collection are achieved.

Abstract: Exemplary embodiments of the present disclosure are directed to limiting a rate or pressurization in a reconfigurable pressurized flow system for which different system configurations can have different system volumes. In exemplary embodiments, the system can determine a limit for the rate of pressurization by configuring the system for a closed system rate of pressurization, measuring the closed system rate of pressurization at a set flow rate, and determining a relationship between the closed system rate of pressurization and the flow rate. The system can use the relationship to dynamically set the limit for different flow rates in the system.

Abstract: The present disclosure relates to controlling the average enthalpy of a mobile phase in a column that is part of a carbon dioxide based chromatographic system. By controlling average enthalpy, separations can be optimized, and method development and transfer between different carbon dioxide based separation systems can be more efficient.

Abstract: A thermal system for use in a column manager of a liquid chromatography system comprises a plurality of spatially separated individually controlled thermoelectric chips. A column module houses a plurality of thermally conductive troughs. Each trough resides in a separate thermal zone to be thermally conditioned individually by one of the individually controlled thermoelectric chips. Each trough is adapted to hold one or more liquid chromatography columns therein. A plurality of spatially separated thermal bridges includes a first thermal bridge thermally coupling one of the thermoelectric chips to a first one of the plurality of troughs and a second thermal bridge of the plurality of thermal bridges thermally coupling another of the thermoelectric chips to a second one of the plurality of troughs.

Abstract: A column-conditioning enclosure includes a column chamber adapted to hold one or more chromatography separation columns. A duct system provides an airflow path around the column chamber such that the one or more chromatography separation columns held within the column chamber are isolated from the airflow path. An air mover disposed in the airflow path generates a flow of air within the duct system. A heat exchanger system disposed in the airflow path near the air to exchange heat with the air as the air flows past the heat exchanger system. The air circulates through the duct system around the column chamber, convectively exchanging heat with the column chamber to produce a thermally conditioned environment for the one or more chromatography separation columns held within the column chamber.

Abstract: A passive pre-heater assembly includes a thermally conductive heat-spreading block and a plurality of passive pre-heaters in thermally conductive communication with the heat-spreading block. The plurality of the pre-heaters exchanges heat with the thermally conductive heat-spreading block. Each pre-heater includes a thermally conductive base in thermal communication with the heat-spreading block, and a plurality of thermally conductive fins is in thermal communication with the thermally conductive base. The plurality of fins of each pre-heater exchanges heat convectively with ambient air and conductively with the thermally conductive base of that pre-heater. A given one of the passive pre-heaters further comprises a tube in thermally conductive contact with the thermally conductive base of the given passive pre-heater. The thermally conductive heat-spreading block exchanges heat with a fluid passing through the tube of the given passive pre-heater.

Abstract: Low-pressure and high-pressure reciprocating and rotary applications use seal assemblies to prevent leakage. One embodiment of a seal assembly includes a major annular body having opposing spaced-apart annular lips extending from a heel portion. The major annular body has a bore extending through the heel portion. A first spring is disposed between the lips, biasing the lips apart. A minor annular body extends from one of the lips of the major annular body. The minor annular body has opposing spaced-apart walls that extend from a base region and form a pocket. A second spring is disposed in the pocket between the spaced-apart walls, biasing the walls apart. During actuator operation, pressurized fluid urges one wall of the minor annular body against a pump head surface to produce a face seal and one of the lips of the major annular body against a rod surface to produce a radial seal.

Abstract: A thermal system for use in a column manager of a liquid chromatography system comprises a plurality of spatially separated individually controlled thermoelectric chips. A column module houses a plurality of thermally conductive troughs. Each trough resides in a separate thermal zone to be thermally conditioned individually by one of the individually controlled thermoelectric chips. Each trough is adapted to hold one or more liquid chromatography columns therein. A plurality of spatially separated thermal bridges includes a first thermal bridge thermally coupling one of the thermoelectric chips to a first one of the plurality of troughs and a second thermal bridge of the plurality of thermal bridges thermally coupling another of the thermoelectric chips to a second one of the plurality of troughs.

Abstract: Exemplary embodiments are directed to modular solenoid valve kits and associated methods, generally involving a valve body that includes a plurality of actuator section components and a plurality of head section components. The plurality of actuator section components includes a drive solenoid, a solenoid return spring, a stroke calibration collar and an actuator-to-head calibration collar. The plurality of head section components includes a needle, a stem return spring, a seal and a seat. The plurality of actuator section components and head section components are adapted to be interchanged to create a pull-through normally open valve, a pull-through normally closed valve, a push-in normally open valve and a push-in normally closed valve. That is, the kits and methods allow for modification of one valve type (e.g., a pull-through normally open valve, a pull-through normally closed valve, a push-in normally open valve and a push-in normally closed valve) into a different type.