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: 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 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.