AN IMPROVED MICROMETHOD FOR VANCOMYCIN DETERMINATION BY HIGH-PERFORMANCE LIQUID-CHROMATOGRAPHY

A micromethod using reversed-phase high-performance liquid chromatography for the analysis of vancomycin in human serum or plasma was developed. Ristocetin was used as the internal standard. Chromatographic conditions included an amino propyl column, a mobile phase with 62% acetonitrile and 38% sodium phosphate buffer (pH 7.0), a total run time of 10 min, and ultraviolet absorbance detection at 225 nm. Multilevel calibration was found to be linear between 1.0 and 100 mu g/ml with correlation coefficients of the calibration line slope consistently > 0.999. Recovery of vancomycin from serum was nearly complete, and no interference from commonly used drugs was observed. This procedure is simple, sensitive, rapid, precise, selective, and requires only 50 mu l of serum or plasma for complection.