Ketoprofen analysis in serum by capillary electrophoresis

A method for the quantification of ketoprofen, a new non-prescription non-steroidal anti-inflammatory drug, in serum, by capillary zone electrophoresis for therapeutic monitoring and emergency toxicology is described. Serum is deproteinized with acetonitrile in the presence of an internal standard to remove serum proteins and to induce sample stacking. The migration time was about 10 min. The assay was linear between 1-10 mg/l without any interferences. The method compared well to an HPLC assay. The HPLC afforded a better detection limit, but the CE was less expensive to operate. This method demonstrates that capillary electrophoresis is a simple and effective method for determination of ketoprofen as well as other drugs in human serum at levers close to 1 mg/l.