RESEARCH PAPER Uptake calibration of polymer-based passive samplers for monitoring priority and emerging organic non-polar pollutants in WWTP effluents Oscar Posada-Ureta 1 & Maitane Olivares 1 & Leire Zatón 1 & Alejandra Delgado 1 & Ailette Prieto 1 & Asier Vallejo 1 & Albrecht Paschke 2 & Nestor Etxebarria 1 Received: 11 October 2015 /Revised: 27 January 2016 /Accepted: 1 February 2016 # Springer-Verlag Berlin Heidelberg 2016 Abstract The uptake calibration of more than 12 non-polar organic contaminants by 3 polymeric materials is shown: bare polydimetilsiloxane (PDMS, stir-bars), polyethersulfone tubes and membranes (PES) and polyoxymethylene mem- branes (POM), both in their free form and membrane- enclosed sorptive coating (MESCO). The calibration process was carried out exposing the samplers to a continuous flow of contaminated water at 100 ng mL -1 for up to 28 days, and, consequently, the sampling rates (Rs, mL day -1 ) of several organic microcontaminants were provided for the first time. In situ Rs values were also determined disposing the samplers in the effluent of a wastewater treatment plant. Finally, these passive samplers were applied to monitor the effluents of two wastewater treatment plants. This application lead to the con- firmation of the presence of galaxolide, tonalide and 4-tert- octylphenol at high ng mL -1 levels, as well as the identifica- tion of compounds like some phthalates and alkylphenols at levels below the detection limits for active sampling methods. Keywords Passive sampling calibration . Organic microcontaminants . Polymeric materials . Sampling rates . WWTP monitoring Introduction The production of thousands of chemicals and their use from industrial applications to food or drug production is one of the fates of modern world. Many of those chemicals have been released in the environment for decades but until recently they were mostly missed or simply ignored [1]. Thankfully, we are becoming aware of the importance of nature conservation to maintain and improve our quality of life, welfare and health. Therefore, models of sustainable development are reflected in new regulations working towards ecosystem protection [2]. In the European Union, the regulatory frame is usually bound to the Water Framework Directive (WFD, 2013/39/EU) and the Marine Strategy Directive (MSD, 2008/56/EC), and they de- termine the Environmental Quality Standards (EQS) to be met. The prioritisation of chemical pollutants is established to manage efficiently the monitoring requirements and to assess the chemical status of the aquatic media in terms of the com- pliance with the regulatory EQS or the variation patterns of the contamination [3]. As a consequence, it is important to high- light the key importance of reliable sampling plans and mea- suring techniques to fulfil the quality requirements [4]. Active sampling approaches are chosen in the way grab sampling or biomonitoring are typically used. As an alterna- tive, passive sampling approaches offer integrative concentra- tion values, i.e. time-weighted average concentrations (C TWA ) of the freely dissolved fraction, which is usually linked with the bioavailable fraction [5]. Moreover, passive samplers al- low to measure organic microcontaminants at very low con- centrations [6, 7]. Consequently, passive sampling devices not only provide cost-effective methods to support reliable sam- pling plans but also support exposure analysis more directly than the total concentrations typically given through active sampling approaches. In fact, as it has been deeply discussed Electronic supplementary material The online version of this article (doi:10.1007/s00216-016-9381-7) contains supplementary material, which is available to authorized users. * Nestor Etxebarria nestor.etxebarria@ehu.eus 1 Department of Analytical Chemistry, Faculty of Science and Technology, University of the Basque Country (UPV/EHU), PK. 644, 48080 Bilbao, Spain 2 Department of Ecological Chemistry, UFZ Centre for Environmental Research, Permoserstraße 15, 04318 Leipzig, Germany Anal Bioanal Chem DOI 10.1007/s00216-016-9381-7