Analytical determination of oestrogenic endocrine disruptors: the method of choice for wastewater treatment plant effluents

Environmental context Endocrine disrupting compounds (EDCs) are among the most recently targeted micropollutants detected in wastewater treatment plant (WWTP) effluents and in aquatic environments. There is a need for the development of robust analytical methods for most relevant estrogenic EDCs. This study provides optimisation of analytical techniques and addresses several relevant aspects that are often overlooked in the literature. The method was finally successfully employed for the analysis of WWTP effluents. Abstract Two analytical approaches – liquid chromatography–tandem mass spectrometry (LC-MS/MS) and gas chromatography–tandem mass spectrometry (GC-MS/MS) methods – were compared for the simultaneous determination of the 19 most important oestrogenic endocrine disrupting chemicals (EDCs), such as 17β-oestradiol, oestrone, 17α-ethinyloestradiol, bisphenol A and triclosan in wastewater treatment plant effluents. To lower the instrument limits of detection (ILODs), a derivatisation step preceded detection in both methods. The stability, sensitivity and ease of use of dansylation (Dns) for LC-MS/MS and trimethylsilylation (TMS) for GC-MS/MS derivatives were evaluated before method validation. TMS derivatisation products were highly unstable over time. Parameters such as susceptibility to matrix effects and the stability of monodansylated and didansylated derivatisation products of phytohormones are discussed. Lower ILODs of highly potent EDCs (0.11 ng mL−1 for 17β-oestradiol, 0.01 ng mL−1 for 17α-ethinyloestradiol and 0.22 ng mL−1 for oestrone) and stability of derivatisation products within 7 days were achieved using LC–MS/MS; therefore, further validation of this method at environmentally relevant concentrations was conducted. The method limits of detection (MLODs) met the requirements of the European Union defined in Directive 2008/105/ES for 17α-ethinyloestradiol (0.035 ng L−1) and 17β-oestradiol (0.4 ng L−1). Twenty samples of wastewater treatment plant effluent from the Czech Republic were screened using LC-MS/MS. Fifteen of the EDCs were detected in at least one sample. The most abundant EDCs were bisphenol A, with a concentration up to 1107 ng L−1, and triclosan, with a concentration up to 76 ng L−1. No seasonal trend between late spring and autumn samples was observed in the frequency or quantity of analytes.