A reversed-phase system is described for the simultaneous isocratic separation of coproporphyrin I, II, III and IV isomers. The retention behaviour of coproporphyrin I and III is studied in detail. The method is suitable for both analytical and semi-preparative separation.

Rapid, Fully Automated Measurement of Plasma Homocyst(e)ine with the Abbott IMx#{174} Analyzer. Mohammed T. Shipchandler, Edwin G. Moore 991 Candidate Reference Method for Determining Serum Creatimne by Isocratic HPLC: Validation with Isotope Dilution Gas Chromatography-Mass Spectrometry and Application for Accuracy Assessment of Routine Test Kits. Linda M. Thienpont, Katrien G. Van Landuyt, Di...

A simple fast and precise reverse phase high performance liquid chromatographic method has been developed for the determination of Primidone Tablets. A symmetry (5μ, 150 x 4 .6mm column) in isocratic mode with methanol: Water (50:50) as mobile phase. The Flow rate is1.0ml/min and effluent is

External flavone aglycones in the overground parts of Veronica chamaedrys L. (Scrophulariaceae) have been analysed by isocratic reversed-phase high performance liquid chromatography. Luteolin, apigenin, luteolin-3'-methyl ether and scuterallein-6,4'-dimethyl ether have been identified. The latter compound is a new flavonoid identified in Veronica genus.

We describe a liquid-chromatographic assay for cyclosporin A in blood and plasma. The method is sensitive enough to allow quantitation of the drug at concentrations observed clinically, is isocratic, required no derivatization, and takes only 10 min of analysis time.

2.2. THEORETICAL BACKGROUND OF HPLC ........................................................................................ 65 2.2.1. Direct measurement of lipophilicity by chromatographic methods ....................68 2.2.2. Measurements of lipophilicity using isocratic chromatographic retention ......70 2.2.3. Measurements of lipophilicity using gradient chromatographic retention ......73 2...

Method VFD0134J_E HPLC Column: Eurokat H, 10 μm, 300 x 8 mm Order No. 30GX340EKN Phase: Eurokat H, 10 μm Eluent: 0.01 N Sulfuric acid Gradient: Isocratic Flow rate: 0.6 ml/min Temperature: 60 °C Volume: 20 μL (Standard) Detection: UV, 210 nm Substances: Orotic acid, Lactic acid and Acetic acid

Determination of trace amounts of bisphenol A (BPA) may cause problems mainly related to the presence of BPA in solvents (even in LC-MS grade), laboratory vessels, and plastic equipment used for sample preparation. Variable and sometimes significant amounts of BPA present in the background cause problems in obtaining good repeatability of measurements at the ultra-trace levels. Such observation...