Analysis of Environmental Protection Agency priority endocrine disruptor hormones and bisphenol A in tap, surface and wastewater by online concentration liquid chromatography tandem mass spectrometry.
The list of endocrine disrupting compounds (EDCs) defined under U.S. EPA Method 539 was recently expanded to include additional hormones and bisphenol A (BPA). Here, we validated a fast and robust alternative method compliant with Method 539.1 requirements in diverse water matrixes (i.e., ultra-pure water, tap water, surface water, and wastewater influent and effluent). Automated large volume injection solid phase extraction (SPE) coupled on-line to ultra-high-performance liquid chromatography tandem mass spectrometry (UHPLC-MS/MS) was investigated for this purpose. The surveyed molecules included 13 EPA-priority hormones (testosterone, progesterone, medroxyprogesterone, levonorgestrel, norethindrone, androstenedione, estrone, β-estradiol, α-estradiol, equilin, equilenin, ethinylestradiol, estriol) and BPA. Combinations of ionization source and mobile phases were optimized for improved sensitivity. Suitable chromatographic performances were obtained and the implementation of an on-line SPE washing step consecutive to sample loading was investigated. On-line SPE extraction efficiencies in acceptable ranges (64-79%) and detection limits in the order of nanogram per liter or sub-nanogram per liter were obtained. The linearity range extended over 2-3 orders of magnitude, with determination coefficients (R2) typically > 0.9980. Robust precision and trueness complying with acceptance criteria (70-130%) were obtained for the scope of analytes/matrix combinations. Limited internal standard variations were also observed across samples (±18%), well within the ±50% acceptance criterion. The method was successfully applied to field-collected samples in Canada and summed EDC concentrations were reported in the range of 0.80-2.8 ng L-1, 6.8-19 ng L-1, 260-790 ng L-1, and 37-360 ng L-1 in tap water, surface water, effluent and influent wastewater samples, respectively.