Estrogens are routinely used either as contraceptive medicines or in hormone replacement therapy and can enter aquatic environments via the discharge of final effluent waters. Estrogens are believed to have a negative effect on aquatic environments by disrupting the hormonal systems of fish. In EU directive 2013/39/EU fifteen additional priority substances were added to the Water Framework Directive (2000/60/EC) and 17α-ethinylestradiol and 17β-estradiol added to a watch list in order to gather further data on the presence of these compounds in aquatic environments. In this presentation we highlight a method for the analysis of synthetic estrogens in surface and final effluent waters at low ppq levels using LC-MS/MS.
Spiked surface water and final effluent samples were extracted and concentrated using solid phase extraction (SPE). After evaporation and reconstitution in water, the samples were then analyzed by LC-MS/MS using a large volume injection (100µl). The method’s performance was evaluated by assessing linearity, repeatability, sensitivity and recovery. Satisfactory quantitative performance was achieved for all compounds in both surface water and final effluent over appropriate concentration ranges (linear, R² > 0.997, residuals < 15%). Recoveries from surface water were ≥70% and precision good (RSDs <6%). The method showed high sensitivity, achieving the required European (2015/495/EU) LLOQ (PtP s/n=10) levels for each compound in matrix. Low level concentrations of 17α-ethinylestradiol were detected in the final effluent matrix and a standard addition method was used to calculate the concentrations.