An on-line solid phase extraction method coupled with UHPLC-MS/MS for the determination of steroid hormone compounds in treated water samples from waste water treatment plants
An on-line solid phase extraction coupled with ultra-high performance liquid chromatography in tandem with mass spectrometry (SPE-UHPLC-MS/MS) method for the determination of fourteen hormones (four oestrogens, three androgens, four progestogens and three corticosteroids) in waste water samples has been developed. All of the parameters involved in the on-line extraction process have been optimized: type of cartridge, sample volume, loading solvent, solvent of the wash step and the pH of the sample. Moreover, the chromatographic separation and all of the parameters involved in the detection by mass spectrometry have been studied too. The developed method allows for complete analysis (extraction and identification of the analytes) in 14.5 minutes. The method is selective, with satisfactory relative standard deviations (lower than 15% in most cases) and limits of detection and quantification that ranged from 0.5 to 13.2 ng L−1 and from 1.66 to 44 ng L−1, respectively. The recoveries were acceptable for most compounds for effluent samples from different waste water treatment plants (between 50 and 90%). The proposed method has been applied to study effluent samples from three waste water treatment plants from Gran Canaria (Spain). Four steroid hormones of different families have been detected at concentrations ranging from 3.1 to 52.8 ng L−1.