This work describes the optimization, validation and application to real samples of an ultra-high-pressure liquid chromatography tandem mass spectrometry (UHPLC-MS/MS) method for the quantification and confirmation of 11 compounds (atrazine, simazine, terbuthylazine, terbumeton, terbutryn and their main transformation products) in surface and wastewater samples. Most of these analytes are included in the list of priority substances in the framework on European Water Policy. The application of this method to water samples reveals that the most relevant transformation products (TPs) should be incorporated into current analytical methods (which are focused mainly on the determination of unchanged compounds), to obtain a more realistic knowledge on water quality regarding pesticide contamination. TPs are generally more polar and mobile than the parents and they can be transported to the aquatic environment more rapidly than their precursors. Additionally, they can present some degree of toxicity and in fact TPs are also included within the legislation on drinking water as pesticide derivatives.To efficiently combine UHPLC with MS/MS, a fast-acquisition triple quadrupole mass analyzer was used.Working in selected reaction monitoring mode, up to three simultaneous transitions per compound were acquired allowing a reliable identification at ng/L levels. The method developed includes a pre-concentration step based on solid-phase extraction (OASIS HLB cartridges). Satisfactory recoveries (70-120%) and relative standard deviations (<20%) were obtained for all compounds in different water samples types spiked at two concentration levels (0.025 and 0.1 µg/L). The optimized method was found to have excellent sensitivity with instrumental detection limits as low as 50 fg.In addition, the influences of the matrix constituents on ionization efficiency and extraction recovery have been studied in different types of Italian and Spanish surface and urban wastewater. Signal suppressions were observed for all compounds, especially for influent wastewater. The use of isotope-labelled internal standards was found to be the best approach to assure an accurate quantification in all matrix samples.

Lura stream flows in the populated and industrialized\ud conurbation North of Milan, Italy. The area suffers a sprawling\ud urbanization which is leading to major alterations in water\ud quality, hydrology and morphology of streams. These water\ud bodies are known as effluent-dominated streams, because most\ud of the baseflow is given by Wastewater Treatment Plant\ud (WWTP) discharges. In this paper, a 5 year long assessment of\ud Lura stream is presented and the collected data is discussed to\ud understand overall ecological quality. Multivariate analysis\ud carried out on macroinvertebrate assemblages and\ud environmental variables suggests that invertebrate communities\ud suffer severe alteration both upstream and downstream WWTP\ud discharges. Results indicate that the high polluting loads coming\ud from WWTP discharges affect seriously the stream water\ud quality, but the most important cause of impairment are pulse\ud perturbations related to the modified hydrology, causing\ud droughts and flash floods, and to the spills of untreated sewage\ud from overflows during rain events

Structure and function of the Serio River (northern Italy) ecosystem have been evaluated analyzing macroinvertebrate community functional traits. Starting from traits such as Functional Feeding Groups (FFG), Functional Habit Groups (FHG), voltinism and drift behavior, we determined values that can integrate direct measurements of ecosystem attributes and can be used in restoration planning. We collected invertebrates and environmental data in eight sites representative of the longitudinal succession of Serio River environments. High values for most of the ecosystem attributes, indicating good functionality, were confined in three sites of the upstream alpine sector, while downstream the ecosystem was severely impaired and colonized by non-specialized, pioneer communities. The intrinsic information given by ecosystem attributes helped aid the understanding of the health of specific ecosystem functions, thus leading to evaluation of priorities in restoration efforts. This methodology can be a complementary tool in river quality assessment if macroinvertebrate quantitative data are available. Particularly, it can be used in accordance with the new quantitative sampling protocols being adopted in the European Union, and it can define new metrics in a multimetric evaluation system.