Mediator solution influence on the sorption potential of sulfo-conjugated estrogenic steroid hormone and its metabolite in New Zealand dairy farm soils

摘要

Estrogenic steroid hormones have been shown to potentially contribute to damage to wildlife and ecosystem health. Understanding their fate and behaviour is important to assess their risk in the environment. We investigated the sorption potential of three dairy farm soils for an estrogenic conjugated steroid hormone and its metabolite employing a complex solvent extraction scheme using CaCl_2 and artificial urine as mediator solution. The sorption potential of El-3 S was about one order of magnitude lower than for the free counterpart, and the K_f values significantly changed between the two mediator solutions. The calculation of concentration-dependent effective distribution coefficients (K_d~(eff)) revealed that for a range of realistic exposure concentrations in grazed dairying environment, the common approach of employing CaCl_2 may deliver incorrect inferences for a proper risk assessment.