Analysis of thyroid hormones in raw and treated waste water

An analytical method for the quantification of thyroid hormones (3,5,3′,5′-tetraiodo-l-thyronine, 3,3′,5-triiodo-l-thyronine, 3,3′,5′-triiodothyronine, 3,5-diiodothyronine, 3,3′-diiodothyronine) in different water matrices has been developed. The method, consisting of solid phase extraction (SPE) and liquid chromatography–tandem mass spectrometry (LC–MS/MS), was validated for tap and surface water as well as raw and treated waste water. The limits of quantifications (LOQs) were lowest in tap water, where they ranged from 1.1 to 13.3 ng L−1, and highest in raw wastewater (10.5–84.9 ng L−1). Of the target analytes 3,5,3′,5′-tetraiodo-l-thyronine (T4) could be quantified in the influent and effluent of a waste water treatment plant (WWTP) in Finland. The study showed that despite a relatively high removal rate during treatment (66%), part of the incoming T4 will reach the aquatic environment and, due to the high endocrine activity of this compound, further studies are needed in order to assess its environmental fate and impact on natural ecosystems.