Analysis of hormone antagonists in clinical and municipal wastewater by isotopic dilution liquid chromatography tandem mass spectrometry

A comprehensive method was developed for the simultaneous trace analysis of ten hormone antagonist pharmaceuticals (raloxifene, exemestane, letrozole, anastrozole, mifepristone, finastride, tamoxifen, N-desmethyltamoxifen, clomiphene, and toremifene) in municipal sewage and hospital wastewater samples. The target compounds were firstly extracted using an Oasis HLB cartridge, followed by purification by an aminopropyl cartridge, and were then analyzed by liquid chromatography electrospray ionization tandem mass spectrometry in positive ion mode. The recoveries for the analytes based on internal standard calibration in different test matrices ranged from 67.6 to 118.6% (with the exception of mifepristone in clinical wastewater samples), with relative standard deviations less than 20%. The method quantification limits of the ten pharmaceuticals were in the range 0.10-2.0 ng/L. Excluding exemestane and N-desmethyltamoxifen, eight drugs were detected at 0.20-195.0 ng/L in hospital wastewater and municipal wastewater samples from Beijing.