The present disclosure describes a differential refractometer for gradient chromatography. In an exemplary embodiment, the differential refractometer includes a solvent delay volume, an eluent flow meter coupled to an eluent inlet of a sample cell, a solvent flow regulator coupled to an outlet of the solvent delay volume and coupled to a solvent inlet of a reference cell, an instrument controller configured to receive the eluent flow rate from the eluent flow meter, configured to receive the solvent flow rate from the solvent flow regulator, configured to receive a flow rate ratio from a flow rate ratio data source, wherein the flow rate ratio indicates a ratio of the eluent flow rate to the solvent flow rate, and an optical bench configured to measure a difference between a refractive index of the eluent present in the sample cell and a refractive index of the solvent present in the reference cell.

The present disclosure describes a computer implemented method, a system, and a computer program product of determining intrinsic viscosity and Huggins constant of an unknown sample. In an embodiment, the method, system, and computer program product include receiving concentration detector signal values over time from a concentration detector corresponding to a series of aliquots of an unknown sample injected into an instrument chain, receiving specific viscosity values over time from a viscometer corresponding to the series of aliquots, calculating a total mass of each of the aliquots, calculating a first intermediate viscosity value of each of the aliquots, calculating a second intermediate viscosity value of each of the aliquots, and fitting the total mass, the first intermediate viscosity value, and the second intermediate viscosity value to a fitting, resulting in a calculated intrinsic viscosity of the unknown sample and a calculated Huggins constant of the unknown sample.

A method for detecting contamination of a fluid in a fluid container includes providing a reference data set related to a reference composition of the fluid, generating a measured data set related to an actual composition of the fluid in the fluid container, a processing unit comparing the reference data set with the measured data set, and determining whether the fluid is contaminated based on the comparison.

The present disclosure describes a computer implemented method, a system, and a computer program product of determining intrinsic viscosity and Huggins constant of an unknown sample. In an embodiment, the method, system, and computer program product include, receiving specific viscosity values over time from a viscometer corresponding to a series of aliquots of an unknown sample injected into an instrument chain where the instrument chain includes the viscometer, calculating a total mass of each of the aliquots, calculating a first intermediate viscosity value of each of the aliquots, calculating a second intermediate viscosity value of each of the aliquots, and fitting the total mass, the first intermediate viscosity value, and the second intermediate viscosity value to a fitting, resulting in a calculated intrinsic viscosity of the unknown sample and a calculated Huggins constant of the unknown sample.

A method of reducing noise in an output signal of a differential refractive index detection part (RI detection part) of a dual-flow type with an analysis device having the RI detection part includes sending a sample liquid to a sample cell with a sample pump, sending a reference liquid to a reference cell with a reference pump, and detecting a change in direction of travel of light sequentially transmitted through the two cells with a light detector. Before starting RI measurement, a phase difference between the sample pump and the reference pump is adjusted so that a noise that occurs in an output signal of the light detector by propagation of pulsation from the sample pump within the sample cell and a noise that occurs in the output signal of the light detector by propagation of pulsation from the reference pump within the reference cell cancel each other.

The present disclosure describes a differential refractometer for gradient chromatography. In an exemplary embodiment, the differential refractometer includes a solvent delay volume, an eluent flow meter coupled to an eluent inlet of a sample cell, a solvent flow regulator coupled to an outlet of the solvent delay volume and coupled to a solvent inlet of a reference cell, an instrument controller configured to receive the eluent flow rate from the eluent flow meter, configured to receive the solvent flow rate from the solvent flow regulator, configured to receive a flow rate ratio from a flow rate ratio data source, wherein the flow rate ratio indicates a ratio of the eluent flow rate to the solvent flow rate, and an optical bench configured to measure a difference between a refractive index of the eluent present in the sample cell and a refractive index of the solvent present in the reference cell.

The invention provides differential refractive index detectors and methods for the use of differential refractive index detectors. In an exemplary embodiment, a differential refractive index detector includes a flow cell body having a proximal end, a distal end, and a flow axis extending between the proximal and the distal end. The flow cell body includes a first chamber and a second chamber and the fluid conduits coupled to the flow cell body can be tapered to reduce dispersion.

The present disclosure describes a computer implemented method, a system, and a computer program product of determining intrinsic viscosity and Huggins constant of an unknown sample. In an embodiment, the method, system, and computer program product include receiving concentration detector signal values over time from a concentration detector corresponding to a series of aliquots of an unknown sample injected into an instrument chain, receiving specific viscosity values over time from a viscometer corresponding to the series of aliquots, calculating a total mass of each of the aliquots, calculating a first intermediate viscosity value of each of the aliquots, calculating a second intermediate viscosity value of each of the aliquots, and fitting the total mass, the first intermediate viscosity value, and the second intermediate viscosity value to a fitting, resulting in a calculated intrinsic viscosity of the unknown sample and a calculated Huggins constant of the unknown sample.

A plurality of light-receiving elements that are arranged in two rows are provided on a light-receiving surface of a detector. A slit image formed on this detector. One group of a plurality of the light-receiving elements are arranged consecutively in a displacement direction of the slit image to form a row (one light-receiving elements row), and another group of a plurality of the light-receiving elements are also arranged consecutively in the displacement direction of the slit image to form a row (another light-receiving elements row). The one light-receiving elements row and the other light-receiving elements row are in contact with each other.

A plurality of light-receiving elements that are arranged in two rows are provided on a light-receiving surface of a detector. A slit image formed on this detector. One group of a plurality of the light-receiving elements are arranged consecutively in a displacement direction of the slit image to form a row (one light-receiving elements row), and another group of a plurality of the light-receiving elements are also arranged consecutively in the displacement direction of the slit image to form a row (another light-receiving elements row). The one light-receiving elements row and the the other light-receiving elements row are in contact with each other.