Trace analysis of amikacin in human plasma by high-performance liquid chromatography

A simple and sensitive liquid chromatographic method is described for the determination of amikacin in human plasma. The amikacin is derivatized with 1-naphthyl isothiocyanate (NITC) at 70°C. After derivatization, a methylamine acetonitrile solution is added to the reaction mixture to eliminate excess derivatizing agent. The resulting derivative was analysed by HPLC on a LiChroCART RP-C18 column with water-acetonitrile (57:43,v/v) mobile phase and detection at 230 nm. Parameters affecting derivatization of amikacin, including reaction temperature, reaction time and amount of derivatizing agent, were investigated. The linear range for the determination of amikacin in spiked plasma was over 10–52 nmol mL−1; the detection limit (signal-to-noise ratio=3; injection volume, 10 μL) was ca. 1 nmol mL−1. The relative standard deviation was <2.37% for intra-day assay (n=6), 5.80% for inter-day assay (n=6) and relative recovery was >91%.