Determination Of Serum Cephalexin By High Performance Liquid Chromatography

Abstract A simple and specific method for the assay of cephalexin in human serum by high performance liquid chromatography is described. Cephalexin was extracted from serum with 5 fold volume of methanol and chromatographed on a reversed-phase column using 30 % aqueous acetonitrile solution containing 0.005 M sodium 2-propanesulfonate (pH 3.0) as the mobile phase. Cephalexin was detected by the absorbance at 254 nm. Only 20 μl of serum was required and all of the operations for analysis were completed within 10 min. This method was proved to be effective in the rapid monitoring of serum cephalexin concentration in humans who received its ordinal and long-acting preparations.