Abstract: An apparatus for use in liquid chromatography involves a column filled with media bounded axially by first and second porous plates. The column has an inlet end with an inflow region between the inlet end and the first porous plate. The column also has an outlet end with an outflow region between the outlet end and the second porous plate. The inflow region may be substantially longer than the outflow region. The porous plates may be moveable under pressure so as to compress the media.

Abstract: Apparatus for chromatography, featuring a composite chromatography column including a tubular member having an inlet end and an outlet end, where the tubular member includes an innermost first layer comprised of a first material and a second layer comprised of a second material. The chromatography apparatus can also include a first intermediate layer formed from a third material, where at least a portion of the first intermediate layer is disposed between the innermost first layer and the second layer. A second intermediate layer formed from a fourth material, can further be included in the chromatography apparatus, where at least a portion of the second intermediate layer is disposed between the innermost first layer and the second layer. A portion of the second intermediate layer can be disposed between the second layer and the first intermediate layer.

Abstract: A chromatography system including a chromatography column connected to receive a sample and separate different compounds in the sample, a flow-through detector that outputs a signal indicating the presence of compounds in the sample leaving the column, a fraction collector that directs fractions of the sample from the column to separate fraction wells, and an electronic controller that receives inputs from the detector and controls the fraction collector. The electronic controller monitors the signal from the detector over time and initiates a cut from one well to another at the fraction collector when the signal over time experiences a shoulder where the slope of the signal over time does not change in sign but does change by more than a predetermined amount.

Abstract: A chromatography system including a chromatography column connected to receive a sample and separate different compounds in the sample, a flow-through detector that outputs a signal indicating the presence of compounds in the sample leaving the column, a fraction collector that directs fractions of the sample from the column to separate fraction wells, and an electronic controller that receives inputs from the detector and controls the fraction collector. The electronic controller monitors the signal from the detector over time and initiates a cut from one well to another at the fraction collector when the signal over time experiences a shoulder where the slope of the signal over time does not change in sign but does change by more than a predetermined amount.

Abstract: A method of processing a sample comprising introducing a sample into a flow-through device containing a porous solid media therein, and thereafter subjecting the device to microwave energy. Also disclosed is a flow through device including solid porous media therein and attached active components.

Abstract: An apparatus for use in liquid chromatography involves a column filled with media bounded axially by first and second porous plates. The column has an inlet end with an inflow region between the inlet end and the first porous plate. The column also has an outlet end with an outflow region between the outlet end and the second porous plate. The inflow region may be substantially longer than the outflow region. The porous plates may be moveable under pressure so as to compress the media.

Abstract: An apparatus for use in liquid chromatography involves a column filled with media bounded axially by at least one porous member. The column has an inlet end with an inflow region between the inlet and a porous member. The inflow region may be sufficiently long so that a chromatography sample module may be disposed therein. The column may be sufficiently long so that a chromatography sample module may be disposed therein. The column may also have an outlet end with an outflow region between the outlet end and a second porous member. The inflow region may be substantially longer than the outflow region. The porous members may be moveable relative to the column.

Abstract: A liquid chromatography column protection system having a system pump, a bubble trap, and a column includes detectors for monitoring certain system conditions such as the presence of air or overpressurization and valves and controlling means for shutting down system operation when the conditions are detected.

Abstract: A critical angle refractive index detector for production liquid chromatography systems with flow rates as low as 100 ml/min to 25 l/min or higher as the system requires and pressures up to 4000 psi. The detector includes a flow cell with a sensing chamber volume selected to provide maximum detector sensitivity and minimum pressure drop at the maximum flow rate of the system for accurate discernment of critical refractive index peaks of each constituent in the sample. Explosion protected controls for zero and span settings are located to the exterior of a purged safe enclosure containing the system.

Abstract: A method of separating organic materials is disclosed utilizing a chromatographic packing material. This packing material includes a coated support material which is a chromatographically suitable substrate. An immobilized butadiene acrylonitrile polymer coating is provided on the substrate. The copolymer can be crosslinked by gamma radiation, or by means of a crosslinking agent such as dicumyl peroxide. The support material can be silica, alumina, diatomaceous earth, zeolite, porous glass or carbon, but preferably a spherical lamellar shaped crystals of aluminum hydroxide. the aluminum hydroxide crystals are bonded together at a central core and extend radially outward from a central core with a particle density ranging from 0.3 to 2.5 g/cm.sup.3 and a diameter of 2 to 150 microns.

Abstract: A method of separating organic materials is disclosed utilizing a chromatographic packing material. This packing material includes a coated support material which is a chromatographically suitable substrate. An immobilized butadiene acrylonitrile polymer coating is provided on the substrate. The copolymer can be crosslinked by gamma radiation, or by means of a crosslinking agent such as dicumyl peroxide. The support material can be silica, alumina, diatomaceous earth, zeolite, porous glass or carbon, but preferably is spherical lamellar shaped crystals of aluminum hydroxide. The aluminum hydroxide crystals are bonded together at a central core and extend radially outward from a central core with a particle density ranging from 0.3 to 2.5 g/cm.sup.3 and a diameter of 2 to 150 microns.

Abstract: A critical angle refractive index detector for production liquid chromatography systems with flow rates as low as 100 ml/min to 25 l/min or higher as the system requires and pressures up to 4000 psi. The detector includes a flow cell with a sensing chamber volume selected to provide maximum detector sensitivity and minimum pressure drop at the maximum flow rate of the system for accurate discernment of critical refractive index peaks of each constituent in the sample. Explosion protected controls for zero and span settings are located to the exterior of a purged safe enclosure containing the system.

Abstract: An automated bubble trap for a liquid chromatography system includes a bubble trap or reservoir with level sensing devices at spaced elevations so that the liquid chromatography system can be operated unattended on a day to day basis so long as the liquid level is maintained between the liquid sensing elevations. The automated bubble trap will correct a low level condition restoring the liquid level to proper limits. However if a dry line condition is inferred, then the automated bubble trap will shut down the system until the problem is resolved.

Abstract: Precise gradient control is accomplished using a high flow three-way valve, appropriate mixing, and precise metering control. Gradient elution profiles are generated for flow rates above 100 ml/min. Control involves precise selection of two solvents, and correction factors for valve lag times and pump/valve synchronizations. The gradient is controlled simultaneously with other non-timed operations through a single microprocessor controller.

Abstract: A process is disclosed for the control of the particle form of aluminum hydroxide crystals precipitated from an alkali metal aluminate solution which comprises either the use of certain monohydric and polyhydric alcohols or controlling the caustic concentration of the sodium aluminate solution or a combination whereby particles shapes may be produced principally comprising acicular form or principally comprising lamellar form, depending upon the caustic concentration of the alkali metal hydroxide and the vol. % of the alcohol.