Abstract: Methods and devices for the management of fluid flow within nanoscale analytical systems, comprising a freeze thaw valve having differing geomentries to constrict a frozen plug within the freeze thaw segment. The freeze thaw valve is directed to use in high-pressure analytical systems. The geometry of an inner diameter of a channel or tube within a freeze thaw segment is configured to cause constriction of a freeze plug when axial force is applied. The constriction is used in the flow-path of a freeze thaw valve to prevent movement of the frozen plug at high pressures to avoid valve leakage.

Abstract: Methods and devices for the management of fluid flow within nanoscale analytical systems, comprising a freeze thaw valve having differing geomentries to constrict a frozen plug within the freeze thaw segment. The freeze thaw valve is directed to use in high-pressure analytical systems. The geometry of an inner diameter of a channel or tube within a freeze thaw segment is configured to cause constriction of a freeze plug when axial force is applied. The constriction is used in the flow-path of a freeze thaw valve to prevent movement of the frozen plug at high pressures to avoid valve leakage.

Abstract: A modular flow cell having a high optical throughput, a long optical path length and a small cross-section. The modular flow cell configuration includes remote ports or connections for liquid and light input, and liquid and light output. The flow cell includes a flow cell body having two ends, each with a respective end interface secured thereto. The flow cell is configured to formn a part of a modular flow cell assembly. The flow cell body includes a channel having a through-aperture with an inner surface. A light guiding material, e.g. a transparent fluoropolymer material having a refractive index less than the refractive index of common chromatography solvents, is disposed proximate to the channel to form a light guiding through-aperture in the flow cell body.

Abstract: A method and apparatus in which the limitation upon analysis caused by variation of the magnetic susceptibility of the solvent conveying a sample to an NMR spectrometer can be addressed. The solvent composition which is used to bring about elution of analyte from devices such as chromatography columns can be varied without causing a corresponding variation of the solvent composition used to transport the analyte to the NMR spectrometer. The decoupling is achieved by the summing into the chromatographic stream, post column, a solvent composition which is complementary to the instantaneous composition emerging from the column, such that the magnetic susceptibility of the summed streams remains constant.

Abstract: One embodiment of the present coupler comprises two or more conduits for transporting fluid. Each of the two or more conduits has at least one end defining an opening in said conduit, and each of the conduits has an axis running parallel to the flow of fluid through said conduit. The coupler further comprises a housing body having a first housing planar surface. The housing body holds the two or more conduits in alignment wherein the axis of each conduit is substantially parallel, and at least one end of each conduit is aligned about said first housing planar surface. And, the coupler has a cap element having a cap planar surface. The cap planar surface is fixed to the first housing planar surface in sealed engagement. At least one of the first housing planar surface and the cap planar surface has a channel in fluid communication with the opening in the conduits. The channel allows two or more fluid streams, each fluid stream defined by one of said conduits, to be placed in communication.

Abstract: High pressure capillary liquid chromatography solvent delivery is effected at substantially low volume and atmospheric pressure. The low volume solvent composition is subsequently pressurized and expelled at high pressure into a receiving device such as a column. The solvent composition is expelled from a fluid metering system configured to deliver liquids at low pressures to a storage matrix via an isolation valve. The solvent composition is delivered to the storage matrix in reverse order such that the first volume of liquid delivered into the storage matrix is the last volume of liquid expelled out. Liquid pre-existing within the storage matrix is transferred into a fluid accumulator in fluid communication with the storage matrix. The fluid accumulator is enveloped in a pressure caisson which can be pressurized or depressurized in response to sensor signals obtained from a fluid volume displacement transducer and a pressure sensor, in accordance with solvent composition cycle formation.

Abstract: High pressure capillary liquid chromatography solvent delivery is effected at substantially low volume and atmospheric pressure. The low volume solvent composition is subsequently pressurized and expelled at high pressure into a receiving device such as a column. The solvent composition is expelled from a fluid metering system configured to deliver liquids at low pressures to a storage matrix via an isolation valve. The solvent composition is delivered to the storage matrix in reverse order such that the first volume of liquid delivered into the storage matrix is the last volume of liquid expelled out. Liquid pre-existing within the storage matrix is transferred into a fluid accumulator in fluid communication with the storage matrix. The fluid accumulator is enveloped in a pressure caisson which can be pressurized or depressurized in response to sensor signals obtained from a fluid volume displacement transducer and a pressure sensor, in accordance with solvent composition cycle formation.

Abstract: A modular flow cell having a high optical throughput, a long optical path length and a small cross-section. The modular flow cell configuration includes remote ports or connections for liquid and light input, and liquid and light output. The flow cell includes a flow cell body having two ends, each with a respective end interface secured thereto. The flow cell is configured to form a part of a modular flow cell assembly. The flow cell body includes a channel having a through-aperture with an inner surface. A light guiding material, e.g. a transparent fluoropolymer material having a refractive index less than the refractive index of common chromatography solvents, is disposed proximate to the channel to form a light guiding through-aperture in the flow cell body.

Abstract: A modular flow cell having a high optical throughput, a long optical path length and a small cross-section. The modular flow cell configuration includes remote ports or connections for liquid and light input, and liquid and light output. The flow cell includes a flow cell body having two ends, each with a respective end interface secured thereto. The flow cell is configured to form a part of a modular flow cell assembly. The flow cell body includes a channel having a through-aperture with an inner surface. A light guiding material, e.g. a transparent fluoropolymer material having a refractive index less than the refractive index of common chromatography solvents, is disposed proximate to the channel to form a light guiding through-aperture in the flow cell body.

Abstract: A fluid delivery method and apparatus implementing active phasing to actively restore the substantially exact mechanical positions of driven components in a delivery system in order to precisely reproduce the mechanical signature and hydraulic characteristics of the system from run to run without perturbing output flow. The delivery system is configured to intelligently drive pump pistons to a known position and to delivery fluid(s) at a known pressure, and includes a plurality of pump modules each including motor driven syringes having respective pistons configured to reciprocate under control of a control mechanism. Pump phasing is accomplished through a mechanism of compensation delivery of the syringes. An independent, motor-driven syringe of any given pump in a plurality of pumps in a system has the ability to act as a delivering syringe to maintain a prescribed output flow while one other syringe of each of the plurality of pumps is repositioned under load.

Abstract: A fluid delivery method and apparatus implementing active phasing to actively restore the substantially exact mechanical positions of driven components in a delivery system in order to precisely reproduce the mechanical signature and hydraulic characteristics of the system from run to run without perturbing output flow. The delivery system is configured to intelligently drive pump pistons to a known position and to deliver fluid(s) at a known pressure, and includes a plurality of pump modules each including motor driven syringes having respective pistons configured to reciprocate under control of a control mechanism. Pump phasing is accomplished through a mechanism of compensation delivery of the syringes. An independent, motor-driven syringe of any given pump in a plurality of pumps in a system has the ability to act as a delivering syringe to maintain a prescribed output flow while one other syringe of each of the plurality of pumps is repositioned under load.

Abstract: A pumping system for continuously delivering fluid at a selected flow rate to a receiving system. The system includes at least a first and a second pumping unit, each of the individual units comprises a syringe and a valve. The syringe comprises a piston and a piston actuator, cylinder, and pressure sensor. The valve comprises a positively-actuated zero switching volume valve and valve actuator. The first and second pumping units are in fluid communication with one another and are capable of independent actuation. The individual valves are arranged to isolate either the first syringe or the second syringe, respectively, from the receiving system while at least one of the syringes remains in fluid communication with the receiving system whereby system pressure can be continuously monitored and the selected system flow rate maintained.

Abstract: An inner short-term pressure sensitive feedback loop is combined with an outer long-term volumetric delivery feedback loop to supply a substantially constant volumetric flow of mixed fluids to a load. The invention has particular utility in the controlled delivery of solvents for liquid chromatography.

Abstract: A passive fluid mixing system having one or more mixers each comprising a mixing chamber (12), a fluid entrance passageway (18) and a fluid exit passageway (20), the passageways being located at opposite ends of the chamber and displaced substantially 180.degree. from each other and lying at least in part in common plane including the axis (13) of the chamber.