Analysis of sex hormones in groundwater using electron impact ionization

A wide range of estrogenic contaminants has been detected in the aquatic environment, both in natural and synthetic forms. Steroid hormones are endocrine-disrupting compounds, which affect the endocrine system at very low concentrations. This work presents the development of an analytical procedure for the determination of five sexual steroid hormones, 17β-estradiol, estrone, progesterone, and the synthetics contraceptives, 17α-ethynylestradiol and norgestrel in groundwater from Sao Paulo University campus, specifically at Institute of Energy and Nuclear Research (IPEN). The analytical procedure starting with the sample pre-treatment, where the samples were first filtered and then extracted through solid-phase extraction, using Strata-X cartridges, and ending with detection. The separation method used was gas chromatography (GC), and the detection method was mass spectrometry (MS). The ion source used was electron impact ionization which produced an electron beam generated by an incandescent tungsten/thorium filament, which collide with molecules of gas sample. This interaction between the electrons and molecules, produce ions of the sample. The detection limits 0.06μg.L-1 for estrone, 0.13 μg. L-1 for 17β-estradiol, 0.13 μg.L-1 for 17α-ethynylestradiol, 0.49 μg.L-1 for norgestrel and 0.02 μg.L-1 for progesterone were detected in assays matrix. Validating tests were also used in this work. (author)