Trace analysis of amikacin in commercial preparation by derivatization and HPLC

A simple and sensitive liquid chromatographic method has been developed for the determination of amikacin by derivatization. The method is based on the derivatization of amikacin with derivatizing agent, 1-naphthoyl chloride, in pyridine at 30 degreesC for 1 h. After derivatization reaction, a dimethylamine acetonitrile solution was added to the reaction mixture to eliminate the excess derivatizing agent. The derivative was analysed by HPLC on a Deita-Pak C-4 column with water-acetonitrile (15:85, v/v) as the mobile phase and detection at 295 nm. The parameters affecting the derivatization of amikacin, including reaction temperature, reaction time, and the amount of derivatizing agent, were investigated. The linear range of the method for the determination of amikacin was over 17-170 nmol/mL; the detection limit (signal to noise ratio = 5; injection volume, 20 muL) was 5 nmol/ml. Application of the method to the analysis of amikacin in commercial injections has proved satisfactory.