A microfluidic check valve includes an inlet bore, an internal chamber, an outlet bore, and a disk freely movable in the chamber between an open position and a closed position. At the open position, the disk permits fluid to flow from the inlet bore, through the chamber, and to the outlet bore. At the closed position, the disk prevents fluid from flowing in the reverse direction from the chamber into the inlet bore. The check valve may be positioned in-line with a fluid conduit, and/or incorporated with various fluidic devices such as, for example, capillary tubes, fittings, and chromatography columns. The check valve is capable of withstanding high fluid pressures, while featuring a small swept volume, such as a nano-scale volume. The check valve may be utilized, for example, to prevent fluid back flow and isolate pressure pulses in fluid flow systems.

A liquid chromatograph (1) includes a liquid sending pump (14) for sending a mobile phase, a sample injector (4) that injects a sample into an analysis flow path (12) through which a mobile phase from the liquid sending pump (14) flows, a separation column (6) that is provided on the analysis flow path (12) and is to separate a sample that has been injected into the analysis flow path (12) by the sample injector (4) into components, a pressure sensor (16) for detecting a liquid sending pressure in the analysis flow path (12) located at a position farther upstream than the separation column (6), a damper capacity holder (22) that holds an internal capacity of a system through which a mobile phase from the liquid sending pump (14) flows as a damper capacity, a reference value determiner (24) configured to determine a reference value of a fluctuation range of the liquid sending pressure when a liquid sending failure of the liquid sending pump (14) occurs, using at least the damper capacity held by the damper capacity holder (22), and a liquid sending failure detector (26) that is configured to periodically acquire a liquid sending pressure detected by the pressure sensor (16), obtain a fluctuation range of the liquid sending pressure in a certain driving period of the liquid sending pump (14) and detect a liquid sending failure using the obtained fluctuation range and the reference value determined by the reference value determiner (24).

A degasser for at least partially degassing a gas-containing liquid, in particular for a sample separation device, includes a circulation path along which the liquid can be circulated between a liquid accommodation volume and one of an inlet to a consumer unit consuming degassed liquid or a conduit leading to the inlet, a drive unit configured for circulating the liquid in the circulation path, and a filter in the circulation path for filtering particles or debris out of the liquid, wherein the liquid is forced through the filter by the drive unit. The drive unit includes a movable body, in particular a movable piston or a movable membrane, configured for at least partially degassing the liquid by generating a negative pressure in the liquid.

Disclosed is a gradient proportioning valve for liquid chromatography that includes a plurality of inlet ports configured to receive a plurality of fluids, a manifold connected to each of the plurality of inlet ports configured to mix the plurality of fluids in a controlled manner to provide a fluid composition, the manifold including a plurality of fluid conduits internal to the manifold, each of the plurality of fluid conduits receiving fluid through a respective one of the plurality of inlet ports, each of the plurality of fluid conduits operatively communicable to a respective actuation mechanism configured to open and close each of the plurality of fluid conduits in a controlled manner, a common outlet port configured to receive the fluid composition, and a passive fluidic dampening system configured to dampen unwanted fluidic pressure pulses in the manifold where at least one of the plurality of fluid conduits is compliant.

Disclosed is a gradient proportioning valve for use in liquid chromatography that includes a plurality of inlet ports configured to receive a plurality of fluids, a manifold connected to each of the plurality of inlet ports configured to mix the plurality of fluids in a controlled manner to provide a fluid composition, the manifold including a plurality of conduits internal to the manifold, each of the plurality of conduits receiving fluid through a respective one of the plurality of inlet ports, each of the plurality of conduits operatively communicable to a respective actuation mechanism configured to open and close each of the plurality of conduits in a controlled manner, a common outlet port configured to receive the fluid composition, and an active fluidic dampening system configured to dampen unwanted fluidic pressure pulses in the manifold. Liquid chromatography systems and methods are further disclosed.

A liquid delivery device includes at least one liquid delivery pump that delivers liquid, at least one main channel communicating with an outlet of the liquid delivery pump, at least one branch channel branched from the main channel, and a switching valve that has, as a port for connecting channels, at least a port to which the main channel is connected, a port to which the branch channel is connected, at least one output port for outputting liquid delivered by the liquid delivery pump through the main channel, and at least one drain port leading to a drain, and is configured to be selectively switched to a first state, in which the main channel is connected to the output port while the branch channel is not connected to any channel, and a second state in which the branch channel is connected to the drain port while the main channel is not connected to any channel.

A liquid delivery device includes at least one liquid delivery pump that delivers liquid, at least one main channel communicating with an outlet of the liquid delivery pump, at least one branch channel branched from the main channel, and a switching valve that has, as a port for connecting channels, at least a port to which the main channel is connected, a port to which the branch channel is connected, at least one output port for outputting liquid delivered by the liquid delivery pump through the main channel, and at least one drain port leading to a drain, and is configured to be selectively switched to a first state, in which the main channel is connected to the output port while the branch channel is not connected to any channel, and a second state in which the branch channel is connected to the drain port while the main channel is not connected to any channel.

Disclosed is a gradient proportioning valve for liquid chromatography that includes a plurality of inlet ports configured to receive a plurality of fluids, a manifold connected to each of the plurality of inlet ports configured to mix the plurality of fluids in a controlled manner to provide a fluid composition, the manifold including a plurality of conduits internal to the manifold, each of the plurality of conduits receiving fluid through a respective one of the plurality of inlet ports, an actuation mechanism having a piston located within a bored structure surrounding the piston, the actuation mechanism configured to open and close at least one of the plurality of conduits in a controlled manner where the piston and the bored structure have a tight tolerance configured to create a fluid tight seal, and a common outlet port configured to receive the fluid composition.

Disclosed is a gradient proportioning valve for liquid chromatography that includes a plurality of inlet ports configured to receive a plurality of fluids, a manifold connected to each of the plurality of inlet ports configured to mix the plurality of fluids in a controlled manner to provide a fluid composition, the manifold including a plurality of fluid conduits internal to the manifold, each of the plurality of fluid conduits receiving fluid through a respective one of the plurality of inlet ports, each of the plurality of fluid conduits operatively communicable to a respective actuation mechanism configured to open and close each of the plurality of fluid conduits in a controlled manner, a common outlet port configured to receive the fluid composition, and a passive fluidic dampening system configured to dampen unwanted fluidic pressure pulses in the manifold where at least one of the plurality of fluid conduits is compliant.

Disclosed is a gradient proportioning valve for use in liquid chromatography that includes a plurality of inlet ports configured to receive a plurality of fluids, a manifold connected to each of the plurality of inlet ports configured to mix the plurality of fluids in a controlled manner to provide a fluid composition, the manifold including a plurality of conduits internal to the manifold, each of the plurality of conduits receiving fluid through a respective one of the plurality of inlet ports, each of the plurality of conduits operatively communicable to a respective actuation mechanism configured to open and close each of the plurality of conduits in a controlled manner, a common outlet port configured to receive the fluid composition, and an active fluidic dampening system configured to dampen unwanted fluidic pressure pulses in the manifold. Liquid chromatography systems and methods are further disclosed.