Communication. Optimization of the high-performance liquid chromatography assay for virginiamycin determination in mineral premixes

Abstract

An optimized reversed phase high-performance liquid chromatography method for the determination of virginiamycin in mineral premixes is presented. It consists of an extraction of the active components with a mixture of acetone and citric acid (0.5 mol l^–1), supplemented with 2% thioacetamide, followed by centrifugation or filtration and dilution in acetonitrile–water (1 + 1). The validation shows that the method is reproducible, precise, repeatable and linear between 5 and 50 µg ml^–1 of virginiamycin activity.