Determination of endocrine disrupting compounds in drinking waters by fast liquid chromatography-tandem mass spectrometry

Growing attention has been recently paid to safety of food and drinking water, making necessary the adoption of policies for water sources protection and the development of sensitive and rapid analytical methods to identify micropollutants. Endocrine-disrupting compounds (EDCs) have emerged as amajor issue as they alter the functioning of the endocrine system. Since ingestion of EDCs via food is considered themajor exposure route, there is a growing interest in understanding EDC fate during drinking water treatment and inmonitoring potential contamination of surface waters and groundwaters. In this work, a fast liquid chromatography–electrospray ionization–tandemmass spectrometrymethodwas developed for the determination of 4-n-nonylphenol (NP), bisphenol A (BPA), estrone (E1), 17β-estradiol (E2) and 17α-ethinylestradiol (EE2) in drinking waters. In the literature analytical articles seldom provide details regarding fragmentation pathways. In this paper spectra of the five EDCs in negative ESI were interpreted with the support of accurate mass spectra acquired by a quadrupole time-of-flight instrument; fragmentation pathways were also proposed. The chromatographic separation of EDCswas optimized on a Pinnacle DB Biphenylic column with awater–acetonitrile gradient.Quantitative analysiswas performed inmultiple reaction monitoring (MRM) mode using bisphenol A-d16 (BPA-d16) as internal standard; calibration curves showed good correlation coefficients (0.9989–0.9997). All figures of merit of the method were satisfactory; limits of detection were in the range 0.2–0.4 ng/ml. The method was applied to the determination of the analytes in waters sampled by polar organic chemical integrative samplers in a drinking water treatment plant. Rather low concentration of BPA, NP and E1 were measured in the inlet, while none of theconsidered EDCs was detected in the outlet.