A simple, fast, and sensitive method for the extraction through direct saponification, separation, quantification, and identification of 12 cholesterol oxidation products (COPs) and cholesterol in a single isocratic, normal-phase, high-performance liquid chromatography (HPLC) was developed. Three detectors were compared for determination of COPs and cholesterol in fish samples: refractive index...

Cost-effective isolation methods were developed on preparative HPLC, flash LC, and simulated moving bed (SMB) to prepare the process impurity, 3-(aminomethyl)-5-methylhex-4-enoic acid (4-ene impurity), of pregabalin. By a thorough experimental study on the different isolation techniques available, it was concluded that SMB was the most cost-effective. Hence, it was a continuous chromatography t...

Ultrafast reversed-phase high-performance liquid chromatographic (HPLC) separations are often needed for analyses related to combinatorial chemistry, studies in liquid chromatography-mass spectrometry, and other applications in which very rapid sample turnaround is paramount. Unfortunately, no consensus exists regarding the best column technology for optimally performing the desired rapid separ...

Detection of disease often relies on identifying abnormal molecules or imbalanced ratios of normal molecules in body fluids, these being reflections of abnormal metabolism. The study of these molecules and their interactions in both healthy and diseased states aids diagnosis and the monitoring of treatment. To carry out such investigations we need to identify, quantify, and ultimately purify th...

the efficacy of activation methods and coupling were studied in the context of performance in batch and fixed bed binding experiments utilizing cell culture fluids or blood plasma as feedstock. conclusions were drawn regarding selection of solid phase according to pore size, rigidity, ph stability, chemistry of derivation and activation, and gross concentration of immobilized ligand required fo...

background: a simple and sensitive high performance liquid chromatography-electrospray ionization mass spectrometry method has been evaluated for the assignment of clonidine hydrochloride in human plasma. methods: the mobile phase composed of acetonitrile-water 60:40 (v/v) and 0.2% formic acid 20 µl of sample was chromatographically analyzed using a repacked zorbax-xdb-ods c18 column (2.1 mmx30...

The influence of mobile phase composition on the retention of selected test analytes in different normal- and reversed-phase chromatographic systems is studied. A novel adsorption model for an accurate prediction of the analyte retention in the column chromatography with binary mobile phase is proposed. Performance of the model is compared with the retention model reported in the literature. Bo...