Environmental friendly method for urban wastewater monitoring of micropollutants defined in the Directive 2013/39/EU and Decision 2015/495/EU

The fate and removal of organic micropollutants in the environment is a demanding issue evidenced by the recent European policy. This work presents an analytical method for the trace quantification of 37 micropollutants including Priority Substances (Directive 2013/39/EU), substances of the recent watch list (Decision 2015/495/EU) and contaminants of emerging concern: pesticides, multi-class pharmaceuticals and a metabolite, estrogens and one industrial compound. The analytical method was based on solid phase extraction (SPE) followed by ultra-high performance liquid chromatography with tandem mass spectrometry (UHPLC-MS/MS), using eco-friendly solvents (ethanol and ultrapure water) both in the SPE and UHPLC, according to green analytical chemistry principles. Briefly, Oasis® HLB cartridges were used to preconcentrate 100 mL of water samples and the reconstituted extracts were analyzed with a Kinetex™ column under reversed mode, the linear ranges extended to 200 ng L−1 (R2 > 0.99) for all the analytes. The method detection limits were between 0.04 and 2.26 ng L−1 and the method quantification limits were between 0.13 and 6.85 ng L−1. The identity of the compounds was confirmed using two MS/MS transitions and its ion ratios, according to Decision 2002/657/EC. The validated method was applied to wastewater treatment plant samples, assessing the concentration of micropollutants after secondary biological and tertiary UV treatments. Lab-scale photolysis and ozonation experiments were also performed with the secondary effluents, with ozonation showing the best performance for the removal of most of the determined micropollutants.