Systems for use with liquid chromatography for provision of continuous flow or gradient flow in connection with two pumps providing mobile phase to a valve.

Systems for use with liquid chromatography for provision of continuous flow or gradient flow in connection with two pumps providing mobile phase to a valve.

Disclosed herein are an amino acid analysis method and a liquid chromatographic apparatus for improving separation performance of threonine, serine, glycine, and alanine. The method of analyzing amino acids using the liquid chromatographic apparatus equipped with a cation exchange column includes a process for distributing a sample containing threonine, serine, glycine, and alanine as the amino acids, together with an eluent, to the cation exchange column to separate threonine, serine, glycine, and alanine, wherein a column temperature when separating threonine and serine is higher than a column temperature when separating glycine and alanine.

A liquid delivery pump includes a primary plunger pump, a secondary plunger pump fluidly connected in series downstream of the primary plunger pump, and a pressure sensor that detects a system pressure. The liquid delivery pump further includes a liquid delivery control part configured to execute first constant pressure control in a first constant pressure control term and to execute second constant pressure control in a second constant pressure control term. The first constant pressure control term is a term, which is in a liquid delivery cycle consisting of the primary discharge process and the secondary discharge process, in which the primary discharge process is executed, the second constant pressure control term is a part of a term in which the secondary discharge process is executed, and the second constant pressure control term is including a term that is continuous after the first constant pressure control term.

A system includes a phase behavior analysis unit having a housing, a heating system connected to the housing and arranged to heat an interior of the housing, a pressure cell positioned in the interior of the housing, and a three-way valve with one inlet fluidly connected to a chamber in the pressure cell and two outlets. The system also includes a gas chromatograph that is fluidly coupled to the chamber in the pressure cell via the three-way valve.

A dynamic axial compression column is disclosed herein. This dynamic axial column utilized external compression to prevent the creation of end plate space in the column. The dynamic axial column can include a tube defining a first opening, a second opening, and a lumen extending there between. The dynamic axial column can include a first end plate assembly sealing the first opening and movably extending at least partially into the lumen via the first opening, a second end plate assembly sealing the second opening, a plurality of rods extending along the outside of the tube and connecting the first end plate assembly and the second end plate assembly, and a first plurality of compression devices external to the tube and engaging one of the plurality of rods to bias the first end plate assembly towards the second end plate assembly.

A dynamic axial compression column is disclosed herein. This dynamic axial column utilized external compression to prevent the creation of end plate space in the column. The dynamic axial column can include a tube defining a first opening, a second opening, and a lumen extending there between. The dynamic axial column can include a first end plate assembly sealing the first opening and movably extending at least partially into the lumen via the first opening, a second end plate assembly sealing the second opening, a plurality of rods extending along the outside of the tube and connecting the first end plate assembly and the second end plate assembly, and a first plurality of compression devices external to the tube and engaging one of the plurality of rods to bias the first end plate assembly towards the second end plate assembly.

The invention features compact systems and methods for vacuum liquid purification and extraction of a liquid sample.

Systems for use with liquid chromatography for provision of continuous flow or gradient flow in connection with two pumps providing mobile phase to a valve.

The invention features compact systems and methods for vacuum liquid purification and extraction of a liquid sample.