Development and application of a SPE-LC-QTOF method for the quantification of micropollutants of emerging concern in drinking waters from the Brazilian capital

The Brazilian Federal District is located under a savannah climate characterized by an intense dry season, resulting in severe problems related to water availability. This situation motivates the search for alternate water sources, leading to the indirect water reuse in the Paranoá Lake, an artificial reservoir located in the heart of the Brazilian capital. This work aimed the assessment of 35 micropollutants of emerging concern by ultra-performance liquid chromatography coupled to high-resolution mass spectrometry. Solid-phase extraction conditions (Oasis HLB) were optimized by a factorial design. Analytes were then assessed in 0.45 μm filtered samples (1 L) under three different pH by matrix-matched calibration with standard additions and high-resolution multiple reaction monitoring acquisition. Caffeine, bisphenol A and the insect repellant DEET were detected in all investigated samples (n = 14), followed by atrazine (86% of the samples), carbamazepine (71%), paraxanthine (71%), mefenamic acid (64%), nicotine (57%), atenolol (43%) and sulfamethoxazole (43%). Although not frequently detected, the reproductive hormones, estrone, 17β-estradiol and estriol, as well as the ovulation inhibitor 17α-ethinylestradiol were detected in a sample from the Paranoá Lake WTP in concentrations ranging from 3.71 ± 0.08 and 5.6 ± 0.1 ng L−1. Under these levels, risk quotients indicate the potential for adverse effects to both human health and the environment.