Separation and determination of synthetic impurities of norfloxacin by reversed-phase high performance liquid chromatography

A simple and rapid high performance liquid chromatographic method for the separation and determination of synthetic impurities of norfloxacin was developed. The separation was achieved on a reversed-phase C₁₈ column using 0.01 M potassium dihydrogen orthophosphate and acetonitrile (60:40, v/v, pH 3.0) as mobile solvent at a flow rate of 1.0 ml/min at 40 °C and a UV detection at 260 nm. The method was used not only for quality assurance but also for monitoring the chemical reactions during the process development work in the laboratory. It was found to be specific, precise and reliable for determination of unreacted levels of raw materials, intermediates and the finished products of norfloxacin.