1. Section of Environmental Chemistry, Department of Analytical Chemistry, Pharmaceutical University of Denmark, Universitetsparken 2, DK‐2100 Copenhagen Ø, Denmark
2. National Environmental Research Institute, Section of Terrestrial Ecotoxicology, Vejlesøvej 25, DK‐8600 Silkeborg, Denmark
3. Danish Veterinary Institute, Bülowsvej 27, DK‐1790 Copenhagen V, Denmark