A preliminary gradient separation in reversed-phase liquid chromatography of a mixture of 25 solutes (diuretics, probenecide, and atenolol) is carried out using several C18 columns and an aqueous phosphoric acid solution (pH 3.2)-acetonitrile mobile phase as a control. Using this separation, the chromatographic behavior of these solutes is studied using 11 water-soluble primary, secondary, and ...

A continuous flow liquid membrane extraction (CFLME)–C18 precolumn-liquid chromatography system was developed for preconcentration and determination of chlorinated phenols (CPs). After preconcentration by CFLME, which is based on the combination of continuous flow liquid–liquid extraction and supported liquid membrane, CPs were enriched in 960 l of 0.5 mol l−1 NaOH used as acceptor. This accept...

Capillary electrochromatographic (CEC) separations of plant sterols and related esters were evaluated under various conditions. Stationary phases included octadecylsilica (C18) and triacontylsilica (C30). Mobile phases comprised acetonitrile, tetrahydrofuran, and tris(hydroxymethyl) aminomethane buffers in aqueous or non-aqueous systems. Apart from notable differences in component resolution, b...

A simple, selective, accurate high performance liquid chromatographic method was developed and validated for an analysis of Halobetasol Propionate and p-Chlorocresol in pharmaceutical formulations. Chromatographic separation achieved by gradient programme on a C18 column (Waters Novapak C-18, 250 x 4.6mm, 4μm column) utilizing a mobile phases of A (pH 2.5 phosphate buffer) and B (mixture of buf...

A new ZORBAX stationary phase, Agilent ZORBAX Eclipse Plus Phenyl-Hexyl, separated five estrogen type steroids better than a C18 and better than three other phenyl columns under identical conditions, due to its unique selectivity for analytes containing phenyl groups. The comparisons support selectivity as the most important factor to optimize resolution, to separate peaks completely. Selectivi...

We describe a simple, reproducible liquid-chromatographic method for determination of esmolol (a short-acting beta blocker) and its major metabolite in human urine. Esmolol is extracted from urine at a pH of 8.4 into methylene chloride; the more polar metabolite remains in the aqueous phase. We then measure esmolol with a muBondapak C18 column and measure ultraviolet absorbance at 229 nm; the m...

The objective of the study was to develop a high performance liquid chromatography (HPLC) method using ultra violet (UV) detection for the determination of flavoxate HCl in bulk and solid dosage forms by using ibuprofen as the internal standard. Eclipse C18 column (150 mm × 4.6 mm, 5 μm) was used as the stationary phase with a mixture of acetonitrile : 0.1% formic acid in water (75: 25 v/v) as ...

In this study, analytical and preparative HPLC systems were utilized to obtain isoflavones from Korean soybean. The mobile phases were the ternary system of water/acetonitrile/acetic acid. The optimum operating conditions were experimentally determined with the analytical column (C18, 0.46x25 cm 5 micron and the preparative column packed with 15 micron. The experimental variables were the gradi...

Objective of the present study is to develop analytical methods for simultaneous determination of two major biflavones, amentoflavone and heveaflavone, in Biyanling Tablets, thereby providing methodological reference for quality control of anticancer drug Biyanling Tablets. Samples are chromatographed on Diamonsil C18 (4.6 mm × 250 mm, 5 μm) column with a mobile phase of acetonitrile (B)–0.5% a...

The objective of this work was to develop and validate a rapid high performance liquid chromatography (HPLC) method for the quantitative analysis of fluorouracil (5-FU) in polymeric nanoparticles. Chromatographic analyses were performed on an RP C18 column with a mobile phase consisting of acetonitrile and water (10:90, v/v) at a flow rate of 1 mL/min. The 5-FU was detected and quantitated usin...