Suchergebnisse

A simple, fast, highly-sensitive and selective method for the determination of 13 HAAs and dalapon in water has been optimized and validated. The method is based on large volume injection (200 μL) and analyte determination with liquid chromatography coupled to negative electrospray ionization-high resolution mass spectrometry (LVI-LC-ESI(−)-HRMS). High throughput is possible due to minimum sample manipulation and short analysis time (16 min in total). This is the first analytical LC-MS-based method that covers the whole suite of HAAs for which analytical standards are available and dalapon, and thus, represents a less costly option than ion-chromatography-based technologies developed for the same purpose. The method provided satisfactory trueness (91–120%) and precision (<17%) values for all analytes, except for CAA. Matrix effects, always in the form of ionization suppression effects, were not relevant (<25%), except in the case of CAA, and they were all well compensated with the use of internal standard calibration. This methodology allows quantifying HAAs in tap waters at concentrations below 1 μg L−1, except in the case of DBCAA and TCAA (3 μg L−1) and CAA and DCBAA (6 μg L−1). Thus, the presented analytical approach is satisfactory for the routine monitoring of HAA5 in drinking waters and obtaining additional knowledge on the formation and occurrence of other HAAs and dalapon that may be of relevance to ensure the provision of safe drinking water in the future. The concentrations of some of the brominated HAAs in chlorine-quenched disinfected water stored in the dark at −20 °C for seven days decreased between 26 and 46%, and thus, water samples should be analysed within 24 hours of their collection. As part of the validation method, the optimized approach was applied to evaluate two strategies to control HAA concentrations in water, i.e., lowering the water pH during the coagulation-flocculation step to improve process efficiency and using a household water pitcher filtration unit to remove HAAs in tap water. ; CP acknowledges support from Fundación General del Consejo Superior de Investigaciones Científicas (FGCSIC) through the 2nd edition of the ComFuturo Programme. This work was supported by the Government of Catalonia (Consolidated Research Groups 2017 SGR 01404) and the Spanish Ministry of Science and Innovation (Project CEX2018-000794-S). Phenomenex is acknowledged for the gift of the HPLC column and AB Sciex for LC-MS instrumentation loan. Nicola Montemurro and Roser Chaler, from IDAEA-CSIC, are acknowledged for assisstance in the use of the analytical instrumentation. We acknowledge support of the publication fee by the CSIC Open Access Publication Support Initiative through its Unit of Information Resources for Research (URICI). ; Peer reviewed

Reducing the formation of disinfection by-products (DBPs) during the process of water potabilization and proper risk assessment of drinking water requires exploring the potential of the source water and the applied treatment to generate these chemicals. This is actually more challenging in large drinking water networks that use different source waters to satisfy potable water demand. In this regard, this works investigated the formation of DBPs in water matrices that are commonly supplied to the city of Barcelona and its metropolitan area. The regulated trihalomethanes and haloacetic acids were the most abundant DBP classes in these waters, followed by haloacetamides and haloacetonitriles or trihalogenated acetaldehydes (THALs). On the contrary, the formation potential of iodo-DBPs was minor. Mixing of drinking water treatment plant (DWTP) finished waters with desalinated water decreased the overall DBP formation potential of the water but resulted in the increased formation of brominated DBPs after long chlorine contact time. The formation of most DBPs was enhanced at high water temperatures (except for Br-THALs) and increasing residence times. Potential cytotoxicity and genotoxicity of the DBP mixtures were mainly attributed to the presence of nitrogen-containing DBPs and HAAs. ; C.P. acknowledges support from the Secretary for Universities and Research of the Ministry of Economy and Knowledge of the Government of Catalonia and the COFUND Programme of the Marie Curie Actions of the EU's FP7 (2014 BP_B00064). This work was financially supported by the Government of Catalonia (Consolidated Research Groups 2017 SGR 1404-Water and Soil Quality Unit). ; Peer reviewed