Preliminary results of the certification study for the determination of zearalenone in maize.

Twenty-six laboratories from the EU participated in the final interlaboratory comparison study of the Standard Measurement and Testing (SMT) project of the European Commission for the preparation and certification of reference materials for the determination of the Fusarium mycotoxin zearalenone (ZON) in maize.Two different maize materials were distributed to the participants, naturally contaminated maize and 'blank' maize material. Additionally, a common ZON calibrant was provided for the quantification.The participating laboratories employed mainly immuno-affinity column techniques for the clean-up and high performance liquid chromatography (HPLC) followed by fluorescence detection for the final separation and quantification.A good mean recovery of 95.5% and trueness was obtained for the maize samples spiked at 99.5 μg/kg ZON. The relative between-laboratory standard deviations (RSDR) ranged from 6 to 12% for naturally ZON contaminated and spiked maize.