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

Abstract

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 (R) HLB cartridges were used to preconcentrate 100 mL of water samples and the reconstituted extracts were analyzed with a Kinetex (TM) column under reversed mode, the linear ranges extended to 200 ng L-1 (R-2 > 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.