Liquid chromatographic determination of tetracycline antibiotics at an electrochemically pre-treated glassy carbon electrode

Abstract

The electro-oxidation of tetracycline antibiotics has been studied by cyclic voltammetry and differential-pulse voltammetry and a liquid chromatographic method with electrochemical detection for the determination of four tetracyclines is described. The sensitivity of the electrochemically pre-treated electrode was twice that of the untreated electrode with spectrophotometric detection. With the pre-treated electrode, the limits of detection were 0.2 ng for oxytetracycline and tetracycline, 1.2 ng for chlortetracycline and 4 ng for doxycycline. The application of the method to the determination of tetracyclines in drugs is discussed.