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.

A method for anomaly detection and diagnosis in a chromatography system including a sample handling unit, a chromatographic separation unit, and a detection unit is disclosed. The method can include performing, with the chromatography system, a chromatography analysis of a sample to obtain a chromatogram of the sample, the sample including a known quantity of a reference standard. The method can also include determining peak information corresponding to the reference standard in the chromatogram and determining whether the peak information conforms with an expected response of the chromatography system associated with the reference standard. If the peak information does not conform with the expected response, the method can include determining that there is an anomaly in the operation of the chromatography system and diagnosing a cause of the anomaly as relating to the operation of at least one the sample handling unit, the chromatographic separation unit, and the detection unit.

A method for anomaly detection and diagnosis in a chromatography system including a sample handling unit, a chromatographic separation unit, and a detection unit is disclosed. The method can include performing, with the chromatography system, a chromatography analysis of a sample to obtain a chromatogram of the sample, the sample including a known quantity of a reference standard. The method can also include determining peak information corresponding to the reference standard in the chromatogram and determining whether the peak information conforms with an expected response of the chromatography system associated with the reference standard. If the peak information does not conform with the expected response, the method can include determining that there is an anomaly in the operation of the chromatography system and diagnosing a cause of the anomaly as relating to the operation of at least one the sample handling unit, the chromatographic separation unit, and the detection unit.

Methods, devices, and systems for improving the quality of electrospray ionization mass spectrometer (ESI-MS) data are described, as are methods, devices, and systems for achieving improved correlation between chemical separation data and mass spectrometry data.

Methods, devices, and systems for improving the quality of electrospray ionization mass spectrometer (ESI-MS) data are described, as are methods, devices, and systems for achieving improved correlation between chemical separation data and mass spectrometry data.

Provided herein are peptide formulations comprising polymers as stabilizing agents. The peptide formulations can be more stable for prolonged periods of time at temperatures higher than room temperature when formulated with the polymers. The polymers used in the present invention can decrease the degradation of the constituent peptides of the peptide formulations.

Provided herein are peptide formulations comprising polymers as stabilizing agents. The peptide formulations can be more stable for prolonged periods of time at temperatures higher than room temperature when formulated with the polymers. The polymers used in the present invention can decrease the degradation of the constituent peptides of the peptide formulations.

In an LC system using an ODS column (15) and UV detector (17), a cannabis-derived sample is analyzed by gradient elution using a phosphoric acid aqueous solution and phosphoric-acid-containing methanol. A control unit (3) regulates the openings of solenoid valves in a mixer (12) so that the increase rate of the mixture ratio of the phosphoric-acid-containing methanol in a second part of the analysis period is higher than in a first part. By this operation, ten active ingredients (including Total THC, Total CBD and CBN) contained in cannabis can be satisfactorily separated within an analysis time which is equal to or even shorter than approximately 30 minutes. Each ingredient separated by the column (15) is detected by the UV detector (17). An active ingredient identification processor (22) identifies the ten active ingredients based on the retention times of the peaks on a chromatogram created from the detection signals.

In an LC system using an ODS column (15) and UV detector (17), a cannabis-derived sample is analyzed by gradient elution using a phosphoric acid aqueous solution and phosphoric-acid-containing methanol. A control unit (3) regulates the openings of solenoid valves in a mixer (12) so that the increase rate of the mixture ratio of the phosphoric-acid-containing methanol in a second part of the analysis period is higher than in a first part. By this operation, ten active ingredients (including Total THC, Total CBD and CBN) contained in cannabis can be satisfactorily separated within an analysis time which is equal to or even shorter than approximately 30 minutes. Each ingredient separated by the column (15) is detected by the UV detector (17). An active ingredient identification processor (22) identifies the ten active ingredients based on the retention times of the peaks on a chromatogram created from the detection signals.

Disclosed is an organic carbon detector that can be used with a liquid chromatography equipment such as a size exclusion chromatography. The organic carbon detector contains a carbon oxidization subsystem and a stripping and CO.sub.2 detection subsystem arranged and detachably connected with each other in said order. The carbon oxidization subsystem contains a microfluidic agent injection module (1), an inorganic carbon removal module (2), a microfluidic ultraviolet oxidation module (3) and a vacuum pumping system (4), configured to remove inorganic carbons and oxidize organic carbons. The stripping and CO.sub.2 detection subsystem contains a stripping module (7) and a CO.sub.2 detector (12), using a carrier gas to transfer the organic carbon converted gas to the CO.sub.2 detector (12). Also disclosed is a method of using the organic carbon detector in water quality monitoring.