A liquid chromatograph includes: an analysis column; a sample loop that temporarily contains a mixed liquid of a sample and a mixture solvent; and a passage switch valve capable of switching a passage between a load position where the mixed liquid is temporarily held in the sample loop and an injection position where the mixed liquid held in the sample loop is sent to the analysis column. In the liquid chromatograph, a specific passage is formed in each of the load position and the injection position.

A chromatography system comprising at least two pumps, a first pump which is connectable or connected with a liquid reservoir for a first fluid, and a second pump which is connectable or connected with a liquid reservoir for a second fluid, wherein the pump outlet lines from the first pump and the second pump are connected with a connection piece and, viewed in the direction of flow, a chromatography column is provided downstream of this connection piece, wherein, viewed in the direction of flow, an addition unit is provided upstream of the connection piece and a mixer switching valve and a mixer switchable by way of the mixer switching valve are provided between the connection piece and chromatography column, wherein the mixer switching valve has at least two switching positions, wherein the mixer is connectable in a first position and the mixer is bypassable in a second position.

A chromatography method in which the system is used and a conversion kit for converting a high-performance liquid chromatography system into a chromatography system for supercritical fluid chromatography are also disclosed.

A method for determining a state of a fluidic system can include measuring back pressures in the fluidic system at different times and determining a state of the fluidic system. The determination is based on at least the measured back pressures and on additional status information indicative of at least one status of the fluidic system at at least one of the different times.

Method for adapting the concentration of a sample gas in a gas mixture to be analysed by a gas chromatograph assembly (10), the gas chromatograph assembly (10) comprising a sample gas inlet (20) for introducing a sample gas to be analysed, a secondary gas inlet (40), a gas chromatograph infrared sensor (12), a gas chromatograph column (26), and a gas chromatograph bypass (28) parallel to the column (26), characterized by a) introducing an amount of sample gas through the sample gas inlet (20), b) introducing an amount of secondary gas through the secondary gas inlet (40), c) mixing the sample gas and the secondary gas to a gas mixture and conducting the gas mixture via the gas chromatograph bypass (28), d) circulating the gas mixture in a gas conducting loop (52) comprising the gas chromatograph bypass (28), the gas chromatograph infrared sensor (12) and not comprising the gas chromatograph column (26), e) analysing the gas mixture thus obtained by means of gas chromatography employing the gas chromatograph column (26) and the gas chromatograph infrared sensor (12).

A gas sampler (30) is provided with a connection portion (C1) connectable to a sample tank (20), a sample loop (PL) for holding a sample gas introduced from the sample tank (20) to the connection portion (C1), pneumatic switching valves (V1 to V6) for switching a flow path connected to the sample loop (PL), a control piping (81) for transmitting a driving pressure to the switching valves (V1 to V6), a pump (31) for suctioning an inside of the sample loop (PL), and a pressure accumulation tank (80) for accumulating the pressure generated by the operation of the pump (31) as a source pressure.

A gas component detection device includes a column, a sensor, a flow path, and a flow path switch. The column separates a component of gas to be detected. The sensor is, for example, a semiconductor sensor, is connected to the downstream side of the column, and detects a component of gas to be detected. The flow path connects the column and the sensor. The flow path switch is arranged between a flow path and a flow path. The flow path switch switches between and executes a measurement mode in which gas to be detected discharged from the column flows into the sensor, and a discharge mode in which gas to be detected discharged from the column is discharged to the outside.

A method for collecting a sample for sample analysis includes drawing a first portion of the sample into a sample storage portion of a chromatography system while the chromatography system is in a first configuration. The method further comprising switching the chromatography system to a second configuration; sealing an end of a sample pick-up needle and draining a portion of a liquid from the second tubing; switching the chromatography system to a third configuration; drawing a second portion of the sample into the sample storage portion of the chromatography system; switching the chromatography system to an injection configuration; and fluidly connecting the sample storage portion to the chromatography column and supplying the first portion of the sample and the second portion of the sample from the sample storage portion to the chromatography column.

A flowpath switch valve is configured for extended service life by spreading the region, of the sliding surfaces of a stator and a rotor, that is subject to wear over the entirety of the sliding surfaces. The stator has fixed stator flowpaths, and the rotor has rotor flowpaths. A flowpath switch valve, depending on the rotor rotation state, realizes connection patterns that include: a first connection pattern wherein a rotor flowpath 241 connects a fixed stator flowpath 31 and a fixed stator flowpath 32; a second connection pattern wherein the rotor flowpath 241 connects the fixed stator flowpath 31 and a fixed stator flowpath 36; a third connection pattern wherein a rotor flowpath 242 connects the fixed stator flowpath 31 and the fixed stator flowpath 32; and a fourth connection pattern wherein the rotor flowpath 242 connects the fixed stator flowpath 31 and the fixed stator flowpath 36.

A sample dispatcher for a fluid separation apparatus includes a sampling path including a sampling volume, a sampling unit, and a retaining unit. The sampling unit receives a fluidic sample, and the sampling volume temporarily stores an amount of the received sample. The retaining unit receives and retains from the sampling volume at least a portion of the stored sample, and has different retention characteristics for different components of the sample. A switching unit is coupled to the sampling path, a sampling fluid drive, a mobile phase drive, and a separating device. In a feed injection configuration of the switching unit, the mobile phase drive, the separating device, and the sampling path are coupled together in a coupling point for combining a flow from the sampling fluid drive containing the fluidic sample retained by the retaining unit with a flow of the mobile phase from the mobile phase drive.

A liquid chromatograph includes a sample supplier that supplies a sample into a mobile phase, a chip column having a flow path that functions as a separation column on a substrate, a packed column, a switcher configured to be switchable between a first state in which a mobile phase and a sample are guided from the sample supplier to the chip column and a second state in which a mobile phase and a sample are guided from the sample supplier to the packed column, and a detector that detects a sample that has passed through the chip column and a sample that has passed through the packed column.