Simultaneous Separation of Ciprofloxacin, Norfloxacin and Ofloxacin by Micellar Electrokinetic Chromatography

This work describes the development of a simple capillary electrophoresis (CE) method for simultaneous determination of the three most frequently used fluoroquinolone derivatives: ciprofloxacin, norfloxacin and ofloxacin. Due to very similar structural and physicochemical characteristics, ciprofloxacin and norfloxacin cannot be separated by the classic method of capillary zone electrophoresis (CZE). Their separations can be solved using micellar electrokinetic chromatography (MEKC), by adding an anionic surfactant to the buffer solution. The efficiency of the separation can be enhanced through the optimization of analytical parameters. A fast reliable method was developed, and the best results were obtained using a buffer solution containing 25 mmol L-1 sodium tetraborate, 100 mmol L-1 sodium dodecyl sulphate and 5% methanol as organic modifier.