Described is a mixer for a liquid chromatography system. The mixer includes an inlet, an outlet, a first flow channel, and a second flow channel. The inlet receives a fluid flow to be mixed and the outlet provides the mixed fluid flow. Each of the two flow channels is coupled between the inlet and the outlet. The second flow channel includes an offset volume that delays fluid propagation through the second flow channel relative to the first flow channel. The offset volume includes a coiled channel which increases radial dispersion and decreases axial dispersion of a fluid flowing through the offset volume, thereby enabling a further reduction in periodic noise in a detector baseline signal as compared to known split flow mixers for liquid chromatography systems.

This disclosure provides liquid chromatography tandem mass spectrometer (LC-MS/MS) methods and systems for detecting low levels of pesticides and mycotoxins in a test sample. In the disclosed methods and systems, oxalic acid is added to a mobile phase composition of a reverse phase chromatographic separation column. This addition improves the signal for certain pesticides and mycotoxins by a factor of from 1.5 to 9, improving their detection limits in a variety of test samples.

Systems, indicator wipe product, and methods thereof used to detect the presence of cationic polymer residues on a surface are described. In various embodiments, the cationic polymer to be detected comprises a quaternary silane residual antimicrobial. The indicator wipe may comprise a woven, nonwoven, or double-knit fabric, cotton, functional cellulose, or open cell foam material substrate impregnated with an aqueous dye solution comprising a sulfonephthalein dye. The indicator wipe may be configured to differentiate between traditional monomer quaternary ammonium compounds and cationic polymers such as quaternary silane compounds used in residual antimicrobial coatings by color changes on the indicator wipe and by observing if cationic-dye complexes diffuse by chromatography on the indicator wipe.

The present invention discloses a method for product quality control and fingerprint detection of an epimedium brevicornu complex. The method uses high performance liquid chromatography, and can effectively realize the quality control of products containing traditional Chinese medicine components, and especially stable control of the quality of products containing a large quantity of non-traditional Chinese medicine components in formulas. Through step-by-step quality control, product quality fluctuation is reduced and stable quality is ensured. Meanwhile, the method is simple and convenient, does not need additional instruments and standards, saves the cost and is more conducive to actual production.

The present disclosure pertains to methods of separating nucleic acid component compounds from one another. In some embodiments, the methods comprise: (a) loading a sample fluid comprising a plurality of nucleic acid component compounds onto a chromatographic column comprising a zwitterionic stationary phase contained inside the column; (b) flowing a mobile phase through the chromatographic column over a time period thereby forming an eluent in which at least some of the plurality of the nucleic acid component compounds are separated from each other, the mobile phase comprising a polar aprotic solvent, a protic solvent, and a volatile buffer salt, wherein flowing the mobile phase comprises varying a ratio of the protic solvent to the polar aprotic solvent over at least a portion of the time period and varying an ionic strength of the volatile buffer salt over at least a portion of the time period.

A impurity detection method of latamoxef sodium is configured to detect the impurities in latamoxef sodium for injection by using high performance liquid chromatography. A chromatographic condition is as follows: taking Agilent ZORBAX SB-CN cyano bonded silica gel column as a stationary phase, taking 0.005˜0.015 mol/L ammonium acetate solution-methanol as a mobile phase A; taking 0.02˜0.03 mol/L ammonium acetate solution-acetonitrile as a mobile phase B; adjusting a pH value of the ammonium acetate solution to 5.8˜6.5; the present disclosure has advantages of a simple operation, high column efficiency, a moderate tailing factor and a retention time of a main peak, high detection accuracy of strong alkali damage, effective separation between the main peak and each impurity peak without interference, which is conducive to accurately controlling quality of lyophilized powder of latamoxef sodium for injection and ensuring quality of drugs.

Disclosed is a liquid chromatography system and mixer for use therein that includes a first split connected to an inlet, the first split branching the flow of fluid from the inlet into a first path and a second path; a second split connected to an outlet of the first path, the second split branching the first path into a third path and a fourth path; and a third split connected to an outlet of the second path, the third split branching the second path into a fifth path and a sixth path. The first path and the second path are offset by a first predetermined volume, the third path and the fourth path are offset by a second predetermined volume, and the fifth path and the sixth path are also offset by the second predetermined volume.

A process for transferring a method from a starting system to a target system in liquid chromatography, in particular in high performance liquid chromatography, is described. A first chromatogram of the method carried out on the starting system is available or determined. The method developed for the starting system is carried out on the target system without any change in its physical parameters, and a second chromatogram is thereby determined. The two chromatograms of the starting system and the target system are compared, and measures for adjusting the physical system parameters of the target system are derived from the deviations.

A process for transferring a method from a starting system to a target system in liquid chromatography, in particular in high performance liquid chromatography, is described. A first chromatogram of the method carried out on the starting system is available or determined. The method developed for the starting system is carried out on the target system without any change in its physical parameters, and a second chromatogram is thereby determined. The two chromatograms of the starting system and the target system are compared, and measures for adjusting the physical system parameters of the target system are derived from the deviations.

Provided herein are newly discovered methods of analyzing abaloparatide samples for abaloparatide isomers. Additionally, methods of storing and treating with abaloparatide in view of the newly discovered abaloparatide isomers are described.