Abstract: A method of analyzing samples includes loading a sufficient quantity of the sample onto a trap column to overload the trap column; heating an analytical column and the trap column to a greater temperature than the analytical column; and pumping a solvent, to the trap column, having a solvent composition profile that, in cooperation with a temperature differential, causes at least some of the components to elute sequentially from the trap column to the analytical column and focus on the analytical column prior to eluting from the analytical column; or optionally: loading a small-molecule sample onto a cooled portion of an analytical column; heating the analytical column; and pumping a solvent, to the heated analytical column, to elute the components from the analytical column. Chromatographic separation includes: a trap column; a separation column; a trap-column heater; a separation-column heater; a solvent pump unit; and a control unit can be used.

Abstract: An injection device (10) includes a carrier inlet (40), a sample inlet (46), waste outlet (44) and a chamber outlet (64) attached to separation column (66). Valves (52, 54, 56) are used to control flow such that sample flows into chamber (22) and is carried into the chamber outlet (42).

Abstract: Described are techniques for fabricating one or more parts of a valve used in a liquid chromatography system. At least one of a rotor and a stator are provided. The rotor is included in the valve and has a first surface facing a stator. The stator is included in the valve and has a second surface facing the rotor. A pattern is formed in at least one of the first surface and the second surface. Forming the pattern includes compressing the at least one surface by applying pressure thereto causing displacement of material to form at least one groove.

Abstract: Described are techniques for use in connection with analyzing a droplet. One or more droplets of a sample are formed on a surface of a digital microfluidic device. The droplets are manipulated to perform processing using said one or more droplets generating one or more resulting droplets. The one or more resulting droplets may be transferred from the microfluidic device to another device for analysis. The one or more droplets may also be provided to the digital microfluidic device from yet another device or analysis instrument.

Abstract: The present invention is a capillary interconnection fitting and method of clamping a capillary in the fitting that separates a forward ferrule that holds the capillary from a secondary clamping device. The fitting comprises a sealing ferrule, a compression screw and a clamping device. The ferrule is fitted in a compression screw that mates to a fluidic component. The clamping device is decoupled from the ferrule and coupled to the compression screw.

Abstract: Methods and devices for the management of cryogenic agents within analytical systems using freeze thaw valving having an expansion chamber that limits the flow of the cryogenic agent. The expansion chamber is fitted with an expansion nozzle through which a cryogen flows and a porous frit that allows the cryogen to be exhausted. The porous frit initially allows a rapid flow of cryogen into the expansion chamber. This rapid flow lowers the temperature of the expansion chamber causing fluid contents within a freeze thaw segment to freeze. As the cryogen expands into the expansion chamber and turns into a solid, the porous frit is occluded causing the rapid flow to be restricted. The restriction of the cryogen flow by the occlusion of the porous frit allows the freeze thaw valve to use significantly less cryogen. Sublimation of the cryogen trapped within the porous frit provides sufficient cooling to maintain the valve in its closed position.

Abstract: A check valve includes a valve seat and a compliant member that moves to seal the check valve by contacting the valve seat. A method for priming a chromatography solvent pump includes providing the check valve in fluid communication with an outlet of the pump, drawing fluid into the pump from a fluid source, and expelling the fluid from the pump through the valve, thus wetting the check valve. Another method for priming a chromatography solvent pump includes providing the check valve in fluid communication with an inlet of the pump, drawing fluid through the valve into the pump, and expelling the fluid from the pump.

Abstract: A method and apparatus for monitoring and controlling nano-scale flow rate of fluid in the operating flow path of a HPLC system provide fluid flow without relying on complex calibration routines to compensate for solvent composition gradients typically used in HPLC. The apparatus and method are used to correct the flow output of a typical, analytical-scale (0.1-5 mL/min) HPLC pump to enable accurate and precise flow delivery at capillary (<0.1 mL/min) and nano-scale (<1 ?L/min) HPLC flow rates.

Abstract: A method and apparatus for monitoring and controlling nano-scale flow rate of fluid in the operating flow path of a HPLC system provide fluid flow without relying on complex calibration routines to compensate for solvent compositions gradients typically used in HPLC. The apparatus and method are used to correct the flow output of a typical, analytical-scale (0.1-5 mL/min) HPLC pump to enable accurate anti precise flow delivery at capillary (<0.1 mL/min) and nano-scale (<?L/min) HPLC flow rates.

Abstract: Embodiments of the present invention feature a device (11) for performing separations, methods of making and using such device (11). The device (11) includes a tubular member (13) having an exterior surface (17) and an interior surface (19). The interior surface (19) defines a chamber (25) having an outlet end (23) and an inlet end (21) for containing a separation media (15). The chamber (25) has a length dimension extending between the inlet end (21) and the outlet end (23), and at least one width dimension. A separation media (15) is constructed and arranged in a packing of particles in the chamber wherein the particles of the separation media (15) proximal to at least one of the inlet end (21) or outlet end (23) are fused to retain the separation media (15).

Abstract: A high-performance liquid-chromatography apparatus includes a substrate that defines a separation column in fluidic communication with an inlet port of the processing unit. The processing unit is formed of sintered inorganic particles. The apparatus also includes a pump that delivers a solvent to the inlet port at a pressure sufficient for high-performance liquid-chromatography.

Abstract: A thermally controlled variable restrictor device provides variable restriction of fluid flow by temperature-induced viscosity changes. The thermally controlled variable restrictor device allows fast variable fluid control by employing a thermo-electric heater-cooler in intimate contact with a fluid channel containing a fluid thereby effecting rapid viscosity changes in the flowing fluid. The permeability and flow rate of fluids through the variable restrictor device can be manipulated by changing the temperature of a restriction element.

Abstract: A fluid controller apparatus controls fluid flow, such as a solvent gradient flow, in a chromatography system. An apparatus includes a fluid-gradient controller having a fluid reservoir for containing a pump fluid and a pumping device connected to the fluid reservoir for receiving the pump fluid. The pumping device is in fluid communication with parallel-configured first and second solvent lines. The first and second solvent lines each contain a restrictor element and a solvent reservoir. During operation, the pumping device causes the pump fluid to flow through the first and second solvent lines in relation to their respective restriction devices. The pump fluid displaces solvent within the solvent reservoirs. The displaced solvent is mixed to form a solvent gradient.

Abstract: A method and apparatus for monitoring and controlling nano-scale flow rate of fluid in the operating flow path of a HPLC system provide fluid flow without relying on complex calibration routines to compensate for solvent compositions gradients typically used in HPLC. The apparatus and method are used to correct the flow output of a typical, analytical-scale (0.1-5 mL/min) HPLC pump to enable accurate anti precise flow delivery at capillary (<0.1 mL/min) and nano-scale (<?L/min) HPLC flow rates.

Abstract: A method and apparatus for monitoring and controlling the nano-scale flow rate of fluid in the operating flow path of a HPLC system without relying on a nano-scale sensor in the operating flow path. A main flow sensor is disposed in the main flow path between the pump and a flow-divider. A waste flow sensor is disposed in the waste flow path downstream of the splitter. The output signal of the waste flow sensor is subtracted from the output signal of the main flow sensor in a difference circuit. The difference signal is divided by the output signal from the main flow sensor in a divider circuit. The output of the divider circuit represents an empirical split ratio of the flow-divider and is independent of media composition.

Abstract: A method and apparatus for monitoring and controlling the nano-scale flow rate of fluid in the operating flow path of a HPLC system without relying on a nano-scale sensor in the operating flow path. A main flow sensor is disposed in the main flow path between the pump and a flow-divider. A waste flow sensor is disposed in the waste flow path downstream of the splitter. The output signal of the waste flow sensor is subtracted from the output signal of the main flow sensor in a difference circuit. The difference signal is divided by the output signal from the main flow sensor in a divider circuit. The output of the divider circuit represents an empirical split ratio of the flow-divider and is independent of media composition.

Abstract: A method for supplying solvent to an ultra-high pressure liquid chromatography system using a hydraulic amplifier. The hydraulic amplifier system includes a hydraulic cylinder comprising a primary piston chamber in which a primary piston is disposed and a secondary piston chamber in which a secondary piston is disposed. The cross-sectional area of the primary piston is larger than the cross-sectional area of the secondary piston. The difference in the cross-sectional areas of the pistons creates an amplification of the pressure in the primary piston chamber and a reduction in flow rate.

Abstract: A freeze-thaw valve and a method of micro-machining the freeze-thaw valve is provided and includes a valve housing, wherein the valve housing defines a housing cavity and includes a housing inlet, a housing vent, a capillary tubing inlet and a capillary tubing outlet. A valve body is provided, at least a portion of which is lithographically constructed, wherein the valve body includes a refrigerant inlet, a refrigerant outlet and an expansion chamber. The expansion chamber is disposed to communicate the refrigerant inlet with the refrigerant outlet and includes a restriction region having a flow restriction. Additionally, the valve body is disposed within the housing cavity to form an insulating channel between the valve housing and the valve body.

Abstract: A method and apparatus for monitoring and controlling the nano-scale flow rate of fluid in the operating flow path of a HPLC system. A first flow sensor is disposed in a first flow path between a first flow-divider and a fluidic tee. A second flow sensor is disposed in a second flow path between a second flow-divider and the fluidic tee. A first recycle flow restrictor is disposed in the first recycle flow path in fluid communication with the first flow-divider. A second recycle flow restrictor is disposed in the second The permeability of each recycle flow restrictor can be selected to produce a desired flow rate with each respective flow path. The output signals of the first and second flow sensors to control output of a pump within each flow path.

Abstract: A method and system for measuring the flow rate of a liquid or gas within a flow channel utilizing a centrally located excitation source and a plurality of sensors. The excitation source is comprised of a heating element coupled with an alternating current generator. Of the plurality of sensors, at least one of the sensors is located in a position upstream of the excitation source location, and additionally a second of the plurality of sensors is located in a position downstream of the excitation source. Instantaneous fluid flow rate is calculated utilizing a high gain differential amplifier electrically coupled to the sensors, wherein the convectively induced inductive gradient of the flowing fluid is compared to the symmetrical zero flow induction gradient. Following such a comparison, a voltage signal proportional to the flow of fluid within the channel is derived.