1. Institute of Food Safety and Toxicology, Danish Veterinary and Food Administration, Mørkhøj Bygade 19, DK-2860 Søborg, Denmark, Division of Nutrition, P.O. Box 27 (Viikki, Latokartanonkaari 9), FIN-00014, University of Helsinki, Finland, and Institute of Pharmaceutical and Analytical Chemistry, Royal Danish School of Pharmacy, Universitetsparken 2, DK-2100 Copenhagen, Denmark