Determination of natural and synthetic oestrogens in surface water using gas chromatography-mass spectrometry

A simple and sensitive gas chromatography method was developed to determine a group of oestrogens in surface water. In the first stage of analysis, enzymatic hydrolysis of oestrogen metabolites with glucuronidase AS-HP was performed. Free compounds were extracted from 200 mL of water sample on C18 SPE column (6 mL, 1000 mg). The evaporated extract was subjected to derivatisation with a mixture of MSTFA/NH4I/DTT (1000:2:5, v/w/w). The separation of the analytes on HP-5ms capillary column was conducted. The method was validated according to the Commission Decision 2002/657/EC. Recovery in spiked samples ranged from 90% to 120 % with standard deviation lower than 30% for all examined compounds. The decision limit and detection capability of five oestrogens were in the range of 0.3-0.6 ng L^-1 and 0.5-0.9 ng L^-1, respectively. Nineteen water samples collected from different sites of several Polish rivers and lakes were tested for the presence of oestrogens. Some target compounds such as 17α-oestradiol, 17β-oestradiol, oestrone, oestriol, and 17α-ethynyloestradiol were found in trace amounts in the analysed samples. The highest concentration observed for oestradiol reached 23 ng L^-1.