Introduction. The general objective of the ECHIBIOTEB research program (“Innovating tools for sampling, chemical and biological analyses for the diagnosis of wastewater advanced tertiary treatments and sludge treatments”, 2011-2014, financed by the French National Research Agency) is introduced in a previous presentation. Briefly it consists in developing new tools for the determination of the efficiency of advanced treatments, especially for the sampling. This presentation will describe the potential of Polar Organic Chemical Integrative Sampler (POCIS) for the monitoring of pharmaceuticals in water, compared to grab sampling. Analytical methodology. Until today, two campaigns were performed in order to follow the efficiency of ozone (O3) treatment, alone and coupled with Granular Activated Carbon (GAC) by exposing 20 POCIS before and after the wastewater treatment during 28 days. Each triplicate, associated to a field blank, is dedicated to a kind of analysis (pharmaceuticals, alkylphenols, and biological analysis, for example). In parallel, grab samplings were achieved after 0, 14 and 28 days of POCIS exposition in order to compare these two approaches. 104 molecules belonging to several therapeutic classes such as antibiotics, -blockers, antineoplastics, antivirals, phosphodiesterase type 5 inhibitor (PDE 5), analgesics, broncholidators, non-steroidal anti-inflammatory and psychiatric drugs, lipid regulators and stimulants, were analysed. Therefore, in order to determine the in-situ rate constants of exposed POCIS, 3 Reference Performance Compounds (PRC) were previously added in the adsorbant phase: salbutamol-d3, caffeine-13C and desisopropylatrazin-d5 (DIA d5) and laboratory calibration on pharmaceuticals were performed. Solid Phase Extractions (SPE) were carried out on the different samples depending on compound classes and, then, analyses were performed by liquid phase chromatography coupled with tandem mass spectrometry (LC-MS/MS). Results. Among targeted compounds, 39 molecules were not detected in any samples of wastewater, in the dissolved phase and 32 molecules in any POCIS samplers. As illustrated in Figure 1a, concentrations upstream from the treatments are higher than those downstream; whatever is the nature of wastewater process. Betablockers, macrolides, psychiatric drugs, fluoroquinolones and quinolones are the most abundant compounds upstream these processes and downstream, only two classes (Betablockers and stimulants) remain present as relatively high concentrations. Therefore, it seems that GAC and GAC+O3 treatments involve a drastic reduction of micropollutant concentrations in wastewaters. Regarding concentrations determined in the adsorbant phase of passive samplers (Figure 1b), the tendency between upstream and downstream coincides well with the one of wastewater samples, in terms of pharmaceutical abundances and between samples too. Figure 2 shows that the number of detected targeted compounds depends on the place of sampling (up or downstream) and on the way of sampling (POCIS vs. grab sampling). For the process using granular activated carbon, based on the measurements of 103 molecules, 13 extra compounds are detected in the adsorbant phase of POCIS compared to the dissolved phase, upstream and downstream the process. Until today, regarding the analysis of 93 molecules for ozone+GAC process, the trend is also observed with the detection of 23 and 17 extra compounds, upstream and downstream respectively. These results show the real interest of this sampling mode by the improvement of methodology sensitivity. Laboratory calibration of passive samplers allow to determine rate constants for more than 25 of target compounds and so, to compare directly the results between integrative and grab sampling in terms of concentrations. This methodology of sampling reveals its interest for the quantification of targeted compounds and has been also applied to the analysis of non-targeted compounds in order to complete the knowledge on the efficiency of such process. The presence of pharmaceuticals and non-targeted compounds could explain the potential toxicity of these samples (wastewater and POCIS extracts). Acknowledgements. The authors wish to thank the program ECOTECH-ECHIBIOTEB, the Aquitaine Region and the European Union (CPER A2E project) for financial support. Europe is moving in Aquitaine with the European Regional Development Fund.