Isco, Inc.

Instrumentation Specialties Company

Teledyne Isco, Inc.

Dionex Corporation

Other

Robert W Allington

Daniel G Jameson

Dale L Clay

Robin R Winter

Yoossef Tehrani

John N Jones

Henry L Walters

Dale A Davison

Scott L Blakley

Abolghassem Y Tehrani

Shaofeng Xie

Mingcheng Xu

Tao Jiang

Robert Joseph Macomber

Larry J Friling

Dale Messer

Philip Bernard Liescheski, Iii

Paul George Wright

John D Hull

Phillip B Liescheski

Curtis W Nicholls

Jon L Curran

Clifford L McDonald, Jr

Fritz Berthold

Jerold B Schmidt

John R Allington

Phillip Bearnard Liescheski, Iii

Dale Lee Clay

Wilhelm Lohr

Lawrence L Sedlak

Wylee D Brunken

Permeable polymeric monolithic materials are prepared in a column casing. In one embodiment, the permeable polymeric monolithic materials are polymerized while pressure is applied through a piston having a smooth piston head in contact with the polymerization mixture. The pressure eliminates wall effect and changes the structure in the column. Similarly, some columns that have a tendency to swell in the presence of aqueous solutions and pressurized while the solution is applied to prevent swelling and wall effect. This procedure also changes the structure in the column. The size of the separation effective openings can be controlled by the amount of the pressure and pores eliminated. Uniformity in the direction flow is improved by controlling polymerization with radiation rather than with conducted heat.

Separation system, components of a separation system and methods of making and using them

To form a smooth gradient and a preparatory liquid chromatographic system having a plurality of syringe type pumps, solvents are alternately drawn and inserted into each cylinder. The solvents are alternately drawn into and through a long narrow path formed of tubing to create axial mixing and spreading out of the interface and then are drawn into the cylinders during the refill stroke of the piston at a sufficiently high velocity to create turbulence. The drawing of the solvents into one side of the cylinder a radial distance from the center creates circular eddy currents.

Liquid chromatographic method and system

To economically perform preparatory chromatography, a plurality of pumps each having a corresponding one of a plurality of pistons and a corresponding one of a plurality of cylinders are driven by one motor to draw and pump solvent simultaneously into corresponding columns. To form a gradient, the pumps are connected to two-way valves that are connected alternately to a first solvent and a second solvent, whereby the time said valve is in a first position controls the amount of solvent drawn from the first reservoir into said pumps and the amount of time in said second position controls the amount of said second solvent drawn from the second reservoir into said pumps and the solvent is mixed in the pumping systems. The detectors are photodiodes mounted to light guides in the flow cells that generate signals related to light absorbance and communicate with a controller, whereby the controller receives signals indicating solute between the light guides and causes collection of solute. An over-pressure system compensates for pressure over a predetermined level.

Pumping requirements for chromatograph applications are for constant flow at high and variable pressures and for accurate programmable control of liquid composition. A two-cylinder pump, pumping system, and associated controls provide an accurate, fixed flow rate. A low pressure gradient former controls composition. During the initial portion of the pumping stroke of a first piston in which fluid is being compressed due to its finite bulk modulus of elasticity its check valve remains closed, a second piston provides all the flow required at a fixed rotational speed. Then, once the first piston has reached its bottom dead center, the control system switches to a constant-pressure control mode, thereby maintaining the flow rate at a fixed value. Constant-pressure control is again switched off either when the second piston's discharge check valve closes, or when the second piston's inlet check valve opens, and pump control returns to fixed rotational speed. Determining the angular displacement at which to effect these control-mode switches is carried out by monitoring the discharge pressure and storing the values of the angular displacement at which the first temporal derivative of pressure changes rapidly. The invention provides novel arrangement for synchronizing the gradient generator by equating recompression volume to recompression volume of the high pressure pump.

High pressure reciprocating pump and control of the same

Pumping for chromatograph applications calls for constant flow at high pressures and for accurate control of liquid composition. A two-cylinder pump, and associated controls provide an accurate, fixed flow rate. During the initial portion of the pumping stroke of a first piston, while its check valve remains closed, a second piston provides all the flow required at a fixed rotational speed. Once the pressure inside the first piston's cylinder has reached that of the discharge and its discharge check valve opens, the control system switches to a constant-pressure control mode, to maintain a fixed flow rate. Constant-pressure control is switched off when the second piston's discharge check valve closes, and pump control returns to fixed rotational speed. Determining the angular displacement at which to effect these control-mode switches is carried out by monitoring changes in the discharge pressure.

Permeable polymeric monolithic materials are prepared in a column casing. In one embodiment, the permeable polymeric monolithic materials are polymerized while pressure is applied through a piston having a smooth piston head in contact with the polymerization mixture. The pressure eliminates wall effect and changes the structure in the column. Similarly, some columns that have a tendency to swell in the presence of aqueous solutions and pressurized while the solution is applied to prevent swelling and wall effect. This procedure also changes the structure in the column. The size of the separation effective openings can be controlled by the amount of the pressure and pores eliminated.

To provide performance particularly in handling supercritical extraction systems, a specially designed pump includes a cam-driven, single-plunger with a cam having a profile that enables the pumping system to avoid destructive reverse torque on the cam, gear train and drive motor after the cam passes top dead center. The plunger includes a seal having one side in contact with the supercritical fluid and a mechanism for supporting and aligning the piston on the other side of the seal to maintain the piston in alignment. The piston drive has Hertzian contact with the piston. The fluid volume leaving the pump is determined by measuring only pressure or other parameters related to flow and movement of the plunger. Measurement of the fluid volume leaving the pump is useful for recording or indicating the flow rate while the pump is operating.

Apparatus and method for super critical fluid extraction

A multiple chamber sample holding cartridge is used with a supercritical fluid extractor that causes membranes dividing the cartridge into chambers to rupture upon the pressurization of the sample cartridge, thereby allowing the intermixing of materials contained in the chambers. The neutral oil and loss determination of soybean and other oilseed oils by supercritical fluid extraction is efficient with this two-chambered sample cartridge.

Multi-chambered supercritical fluid extraction cartridge and processes using it

A variable-orifice fluid restrictor for use with a supercritical extractor or chromatograph includes an inlet line for fluid at a pressure above its critical pressure, an extended tubular probe having an inner and an outer surface and a proximal and a distal end. The proximal end of the probe is disposed toward the inlet line. The distal end of the probe includes an adjustable orifice means adapted for metering the fluid and having first and second orifice members and an adjusting stem having first and second ends. The adjustable orifice means is adjacent to the outer surface of the probe and the orifice means is adjustable with the adjusting stem. The end of the adjusting stem is located at the distal end of the probe and is adapted for moving the first orifice member with respect to the second orifice member to control the adjustable orifice for varying the restriction of fluid passing through the adjustable orifice. The distal end of the probe is inside the collector and the adjusting stem extends outside of the collector.

Apparatus and method for supercritical fluid extraction or supercritical fluid chromatography

An apparatus for supercritical extraction is disclosed herein. The apparatus includes a plurality of containers adapted to hold a different one of a corresponding plurality of samples, a first transport means for carrying the plurality of sample containers, and a second transport means for transporting a selected container from the first transport means to a supercritical extractor. The supercritical extractor includes a heating means having a recess for receiving the selected container, means for passing fluid at a supercritical condition through the selected container, and a receiving means for receiving extractant from the selected container. A programming means is provided to control the first and second transport means.

Apparatus for supercritical fluid extraction

To collect analyte from a supercritical fluid extractor, the collector lifts vials into place by a biasing means that guides the file up to the restrictor where it is sealed. The vial can be moved back down from the collecting mechanism even if frost forms on the vial while the restrictor means remains stationary. This vial is held in place by a guide that contains the seal for sealing the vial when it is raised in place.

Apparatus and method for supercritical fluid extraction

A variable-orifice fluid restrictor for use with a supercritical extractor or chromatograph includes an inlet line for fluid at a pressure above its critical pressure, an extended tubular probe having an inner and an outer surface and a proximal and a distal end. The proximal end of the probe is disposed toward the inlet line. The distal end of the probe includes an adjustable orifice means adapted for metering the fluid and having first and second orifice members and an adjusting stem having first and second ends. The adjustable orifice means is adjacent to the outer surface of the probe and the orifice means is adjustable with the adjusting stem. The end of the adjusting stem is located at the distal end of the probe and is adapted for moving the first orifice member with respect to the second orifice member to control the adjustable orifice for varying the restriction of fluid passing through the adjustable orifice.

Growing community of inventors

Lincoln, NE, United States of America

Robert W Allington