Determination of Tetracyclines in Bovine and Human Urine using a Graphite-Polyurethane Composite Electrode

Abstract

The performance of a bare graphite-polyurethane composite electrode (60 percent graphite, m/m) for the determination of tetracycline in human urine and oxytetracycline in human and bovine urine was evaluated. Using optimized differential pulse voltammetry, limits of detection as low as 2.6 micromoles per liter (tetracycline) and 1.7 micromoles per liter (oxytetracycline) were found in phosphate buffer at pH 2.5. The sample preparation included acidification and centrifugation to remove solid proteins followed by direct analysis. Recoveries between 96 and 100 percent were obtained for the determination of tetracycline and oxytetracycline in fortified urine.