Abstract
Liquid and solid samples from two wastewater treatment plants (WWTPs) on Gran Canaria Island (Spain) have been tested for the presence of compounds with endocrine-disrupting properties. The selected degradation stages were sampled bimonthly from each WWTP over the 12-month period from July 2010 to July 2011. The analytical methods used for the determination of the endocrine-disrupting compounds (EDCs) were based on on-line solid phase extraction, microwave-assisted extraction (MAE), and ultrasonic-assisted extraction (UAE) coupled to UHPLC-MS/MS. All of the hyphenated methodologies employed in this work showed good recoveries (72-104%) and sensitivities, with LODs lower than 7.0 ng L(-1) and 6.3 ng g(-1) for the dissolved and solid fractions, respectively. We have also evaluated the estrogenicity of the samples in terms of their estradiol equivalent concentrations (EEQs). The chemical analysis of the selected EDCs revealed fairly low concentrations for both natural and synthetic oestrogens, alkylphenolic compounds, and bisphenol-A in each of the dissolved, particulate, and sludge samples (ng L(-1) or ng g(-1)). However, the estimated estrogenic activity indicated that the majority of samples could represent an important environmental risk, clearly surpassing the threshold to exert deleterious consequences on living beings.