Liquid chromatography techniques are disclosed. Specifically, the liquid chromatography technique includes providing a liquid chromatography system having a coated metallic fluid-contacting element, and transporting a fluid to contact the coated metallic fluid-contacting element. Conditions for the transporting of the fluid are selected from the group consisting of the temperature of the fluid being greater than 150 C., pressure urging the fluid being greater than 60 MPa, the fluid having a protein-containing analyte incompatible with one or both of titanium and polyether ether ketone, the fluid having a chelating agent incompatible with the one or both of the titanium or the polyether ether ketone, and combinations thereof.

Thermally modulated variable restrictors used in chromatography systems enable independent control of system pressure and linear velocity of a compressible mobile phase passing through a chromatography column. A method for configuring a chromatography system with independent control of system pressure and mass flow rate of a compressible mobile phase includes determining a type of chromatography separation column to be used in the chromatography system, matching a thermally modulated variable restrictor to the type of chromatography separation column for use together during operation of the chromatography system, and bundling the chromatography column with its matching thermally modulated variable restrictor for distribution as a single package.

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.

Provided is a supercritical fluid chromatography method, system, and components comprising such a system wherein a non-polar solvent may replace a portion or all of a polar solvent for the purpose of separating or extracting desired sample molecules from a combined sample/solvent stream. The method and system are designed to eliminate or reduce the amount of polar solvent necessary for chromatographic separation and/or extraction of desired samples to less than or equal to twenty percent polar solvent within the total volume concentration of the total solvents used, and the technique may include one or more of a supercritical fluid chiller, a supercritical fluid pressure-equalizing vessel, and a supercritical fluid cyclonic separator. The supercritical fluid chiller and the use of the chiller allow efficient and consistent pumping of liquid-phase gases employing off-the-shelf HPLC pumps in the supercritical chromatography system using liquid-phase gas mobile phase. The pressure equalizing vessel allows the use of off the shelf HPLC column cartridges in the supercritical chromatography system. The cyclonic separator efficiently and effectively allows for separation of sample molecules from a liquid phase or gas phase stream of a supercritical fluid. The technique may further incorporate the use of one or more disposable cartridges containing silica gel or other suitable medium for use as a chromatographic separation column. The technique may also utilize an open loop cooling circuit using fluids with a positive Joule-Thompson coefficient.

Exemplary embodiments are directed to a gas liquid separator that includes a chamber, a fluid mixture inlet, a solvent outlet and a gas outlet. The gas liquid separator can include a phase-change inducing mechanism disposed in or proximate to the fluid mixture inlet. Exemplary methods of improving separation of a fluid mixture in a gas liquid separator and CO.sub.2-based chromatography flow systems including a gas liquid separator are also provided.

Methods for focusing analyte peaks in liquid chromatography using a spatial temperature gradient are provided. Also provided are methods for focusing analyte peaks and improving resolution using a trap column upstream of a separation column. Further, methods are provided in which the trap column placed upstream of the separation column is packed with a temperature-sensitive polymer/copolymer, and a spatial temperature gradient is applied along the trap column for obtaining improved retentivity by trap column stationary phase, and overall improved resolution of analyte peaks.

Provided is a supercritical fluid apparatus including: an analysis flow path through which a mobile phase flows; a back-pressure control valve provided at a downstream end of the analysis flow path to adjust pressure in the analysis flow path to a predetermined pressure; a small-diameter pipe connected to the outlet of the back-pressure control valve, having an inner diameter allowing internal pressure to be maintained at a pressure higher than the atmospheric pressure; a large-diameter pipe connected to a downstream end of the small-diameter pipe, having a larger inner diameter than the small-diameter pipe; and a large-diameter pipe heating part for heating the large-diameter pipe.

An apparatus for performing liquid chromatography includes a chromatography column, and an insulating member surrounding the chromatography column wherein the insulating member is formed from a vacuum chamber surrounding the chromatography column. Another apparatus for performing liquid chromatography includes a chromatography column, and an insulating member surrounding the chromatography column, wherein the insulating member includes aerogel. Also described is a method of insulating a chromatography column comprising forming a jacket surrounding the chromatography column, and creating a vacuum chamber in an area between the jacket and the chromatography column.

Techniques are described for accelerating thermal equilibrium in a chromatographic column. An apparatus comprises a chromatography column, and a plurality of temperature control units in thermal contact with the chromatography column. A method of performing liquid chromatography comprises setting an inlet of a chromatography column to a first temperature using a first temperature control unit in thermal contact with said inlet, setting an outlet of the chromatography column to a second temperature using a second temperature control unit in thermal contact with the outlet, wherein the first temperature is less than the second temperature; and injecting a sample into a liquid stream that flows through the chromatography column after the inlet is set at the first temperature and the outlet is at the second temperature.

A chemical liquid manufacturing apparatus is provided. The manufacturing apparatus includes at least one filtration medium selected from an ion exchange medium and an ion medium, and a temperature control unit configured to control the temperature of a material to be processed by the at least one filtration medium. A method of manufacturing a chemical liquid using the apparatus is also provided.