1. Department Safety in the Food Chain, German Federal Institute for Risk Assessment, Max-Dohrn-Straße 8-10, 10589 Berlin, Germany
2. State Office for Nature, Environment and Consumer Protection (LANUV), North Rhine-Westphalia, 45659 Recklinghausen, Germany
3. Institute of Animal Science, University of Bonn, 53115 Bonn, Germany
4. Chemical and Veterinary Analytical Institute Münsterland-Emscher-Lippe (CVUA-MEL), 48147 Münster, Germany