Optimization of capillary electrophoretic separation of quinolone antibacterials using the overlapping resolution mapping scheme

The capillary electrophoretic separation of fourteen quinolone antibacterials, viz., cinoxacin, ciprofloxacin, enoxacin, flumequine, lomefloxacin, nalidixic acid, norfloxacin, ofloxacin, oxolinic acid, pefloxacin, pipemidic acid, piromidic acid, rosoxacin and sparfloxacin, was optimized by using the overlapping resolution mapping scheme. Three relevant parameters to run buffer compositions, i.e., the concentrations of sodium cholate and sodium heptanesulfonate, and the volume percentage of acetonitrile, were chosen for optimization. Seven experiments were carried out to obtain the overlapped resolution diagram for locating the area of optimum separations. Following the predicted optimum condition, a baseline separation of the fourteen quinolones was achieved within 8 min.