Rapid determination of zearalenone in edible oils by HPLC with fluorescence detection

A fast, cost-efficient, sensitive and accurate assay method for zearalenone in edible oils is described, as an alternative to gel permeation chromatography (GPC). Oil samples were extracted with an alkaline mixture of methanol and water (methanol +10 g/l aqueous ammonium carbaminate solution, pH 9; 9 + 1, v+v). The pH of the extract was neutralized with hydrochloric acid and then concentrated to dryness. The residue was dissolved with HPLC solvent, and zearalenone was determined by high-performance liquid chromatography with fluorometric detection (HPLC-FLD). The method was successfully validated for two matrices, maize oil and rapeseed oil. The recovery rate was 87%, and the coefficient of variation was 2.8% in a rapeseed oil sample contaminated with 27 µg zearalenone/kg. At a signal-to-noise ratio of 3:1, the method detection limit was 10 µg/kg, which was considered to be adequate in view of the present European Union maximum level of 400 µg/kg.