Disclosed is a system for measuring mass transfer in a membrane and solutions. The system includes: a membrane module 10 including a feed solution reservoir 11 accommodating a feed solution f, a draw solution reservoir 13 accommodating a draw solution d whose osmotic concentration is higher than that of the feed solution f, and a holder 15 supporting a semipermeable membrane m arranged between the feed solution reservoir 11 and the draw solution reservoir 13 and whose performance is to be measured; a feed solution storage tank 20 storing the feed solution f; and a feed solution supply pump 30 supplying the feed solution f from the feed solution storage tank 20 to the feed solution reservoir 11 at a fixed flow rate corresponding to a water flux WF across the membrane m such that the water flux WF is maintained constant.

A control device of a piston pump unit comprising at least two piston-cylinder units that operate in a phase-shifted manner for the purpose of liquid chromatography and to a piston pump unit is described. The control device corrects fluctuations of the system pressure while switching from one piston cylinder unit to the respective other piston cylinder unit. The fluctuations can occur as a result of the cooling of the liquid medium that is heated in an adiabatic manner during a pre-compression phase in the working piston. The control unit controls the piston speed of at least one piston-cylinder unit during the transition phase depending on at least one characteristic, which is ascertained from chronologically previously detected pressure values, such that variations of the system pressure as a result of the cooling of the adiabatically heated medium are at least partially compensated for.

A control device of a piston pump unit comprising at least two piston-cylinder units that operate in a phase-shifted manner for the purpose of liquid chromatography and to a piston pump unit is described. The control device corrects fluctuations of the system pressure while switching from one piston cylinder unit to the respective other piston cylinder unit. The fluctuations can occur as a result of the cooling of the liquid medium that is heated in an adiabatic manner during a pre-compression phase in the working piston. The control unit controls the piston speed of at least one piston-cylinder unit during the transition phase depending on at least one characteristic, which is ascertained from chronologically previously detected pressure values, such that variations of the system pressure as a result of the cooling of the adiabatically heated medium are at least partially compensated for.

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.

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.

Injector (40) for injecting a fluidic sample into a mobile phase in a sample separation apparatus (10), the injector (40) comprising a main flow path (100) between a fluid drive (20) and a sample separation device (30), wherein the fluid drive (20) is adapted to drive the mobile phase and the sample separation device (30) is adapted to separate the fluidic sample that is injected into the mobile phase, a discharge device (104) for discharging an, in particular predetermined, amount of the mobile phase from the main flow path (100), and a supply device (102) for supplying an, in particular predetermined, amount of the fluidic sample and/or of a solvent into the main flow path (100), wherein the discharged amount and the supplied amount compensate each other at least partially.

Injector (40) for injecting a fluidic sample into a mobile phase in a sample separation apparatus (10), the injector (40) comprising a main flow path (100) between a fluid drive (20) and a sample separation device (30), wherein the fluid drive (20) is adapted to drive the mobile phase and the sample separation device (30) is adapted to separate the fluidic sample that is injected into the mobile phase, a discharge device (104) for discharging an, in particular predetermined, amount of the mobile phase from the main flow path (100), and a supply device (102) for supplying an, in particular predetermined, amount of the fluidic sample and/or of a solvent into the main flow path (100), wherein the discharged amount and the supplied amount compensate each other at least partially.

A method of introducing a sample into a separation column includes introducing the sample into a trap column, isolating the trap column from ambient atmosphere and pressurizing the trap column to a first pressure while the trap column is isolated from ambient atmosphere, providing a fluid connection between the trap column and the separation column after pressurizing the trap column to the first pressure, supplying the sample from the trap column to the separation column.

A method of introducing a sample into a separation column includes introducing the sample into a trap column, isolating the trap column from ambient atmosphere and pressurizing the trap column to a first pressure while the trap column is isolated from ambient atmosphere, providing a fluid connection between the trap column and the separation column after pressurizing the trap column to the first pressure, supplying the sample from the trap column to the separation column.

The present invention provides a novel method that is capable of detecting a trifluridine-related substance from a sample containing trifluridine or a salt thereof by high-performance liquid chromatography comprising two steps that are performed under gradient conditions. More specifically, the method is for detecting a trifluridine-related substance, the method comprising the step of subjecting a sample containing trifluridine or a salt thereof to high-performance liquid chromatography using a mobile phase composed of an organic phase and an aqueous phase, wherein the step of high-performance liquid chromatography comprises steps 1 and 2 that satisfy the following requirements: Step 1: the percentage of the organic phase in the entire mobile phase is 1 to 14% by volume; and Step 2: after step 1, elution is performed by applying a gradient of increasing the percentage of the organic phase in the entire mobile phase.