Talanta 85 (2011) 1825–1834 Contents lists available at ScienceDirect Talanta j ourna l ho me page: www.elsevier.com/locate/talanta Determination of various estradiol mimicking-compounds in sewage sludge by the combination of microwave-assisted extraction and LC–MS/MS T. Vega-Morales, Z. Sosa-Ferrera, J.J. Santana-Rodríguez ∗ Departamento de Química, Universidad de Las Palmas de Gran Canaria, 35017 Las Palmas de Gran Canaria, Spain a r t i c l e i n f o Article history: Received 23 February 2011 Received in revised form 16 June 2011 Accepted 7 July 2011 Available online 20 July 2011 Keywords: Alkylphenol Sex hormones Bisphenol-A Microwave-assisted extraction Liquid chromatography Mass spectrometry a b s t r a c t In this work, we present the development and application of a microwave assisted extraction followed by liquid chromatography–tandem mass spectrometry methodology (MAE-LC–MS/MS) for the determina- tion of various estradiol-mimicking compounds in sewage sludge samples. For the purification of the MAE extracts, we have employed a solid phase extraction (SPE) clean-up procedure, previously optimised. The entire method provides recoveries between 71.7% and 103.1%, with relative standard deviation lower than 11.1% and limits of detection ranging from 0.6 to 3.5 ng g -1 . The developed method was applied to samples from three wastewater treatment plants (WWTPs) located in Las Palmas of Gran Canaria (Spain), two of which had a conventional activated sludge treatment (AST), whereas the third treatment plant had an advanced membrane bioreactor treatment (MBR). All of the analytes in the study, including (nonylphenol (NP), octylphenol (OP), and some of their ethoxylated chains AP n EOs (n ≤ 7), 17-estradiol (E2), estriol (E3), 17-ethynylestradiol (EE) and bisphenol-A (BPA)), were found in almost all samples in concentrations ranging from 0.9 to 710.2 ng g -1 . © 2011 Elsevier B.V. All rights reserved. 1. Introduction Endocrine systems involve complex mechanisms that regulate and coordinate bodily functions and maintenance of homeostasis. Secretory glands release hormones, which act as chemical messen- gers that interact with receptors in target cells to trigger specific responses, such as the induction of hormone responsive genes [1]. Therefore, there are various target organ sites in which an environ- mental agent could disrupt endocrine function, especially in the early stages of life [2]. All humans and animals can excrete oestrogens from their bod- ies, which are introduced into the environment through sewage discharge and animal waste disposal. These compounds may inter- fere with the normal functioning of endocrine systems, thus affecting reproduction and development in wildlife and humans [3]. In this sense, the steroids of environmental interest due to their endocrine disruption potential are mainly natural oestrogens (17-estradiol (E2), oestrone (E1) and estriol (E3)) and synthetic oestrogens included in the contraceptive compositions (such as ethynylestradiol (EE) or mestranol (MeEE)). In addition to steroid hormones, non-steroidal substances of widely diverse chemical structures mimic the oestrogen action. This diversity makes it difficult to predict the estrogenicity of ∗ Corresponding author. Tel.: +34 928 454 425; fax: +34 928 452 922. E-mail address: jsantana@dqui.ulpgc.es (J.J. Santana-Rodríguez). xenobiotics based solely on structural analysis [4]. This is the case of the so-called emerging contaminants, previously unrecognised pollutants that are employed in everyday life [5], such as surfac- tants (e.g., alkylphenols ethoxylated (AP n EOs)), plasticisers (e.g., bisphenol-A (BPA)), pharmaceuticals, personal care products, and gasoline additives. Due to the highly lipophilic behaviour of many endocrine disrupting compounds (EDCs), including the more oestrogenic compounds (Table 1), it is expected that these chemicals tend to associate strongly to particulate matter, and therefore to the sedi- ments [6–8]. Thus, the study of these contaminants in wastewater sludge has gained importance in revealing the real fate of EDCs in the environment (it has been reported that over 60% of more estrogenic EDCs are associated to particulate matter and sediments [9–11]); nevertheless, the number of studies involving these con- taminants in the solid phase fraction remain much lower than that of the dissolved phase fraction. The determination of these substances in sewage sludge has importance because wastewater treatment plants (WWTPs) are a sink for organic compounds, and therefore can be viewed as a potential emissary of these substances to the environment if their removal is not complete. In addition, during the past decade, the use of sewage sludge from wastewater treatment plants as an organic amendment has become common practice in Europe to mitigate the low productivity or profitability of several agriculture soils [12], which facilitates the “arrival” of these pollutants to humans through the food chain [13]. 0039-9140/$ – see front matter © 2011 Elsevier B.V. All rights reserved. doi:10.1016/j.talanta.2011.07.051