Bioprofiling of Surface/Wastewater and Bioquantitation of Discovered Endocrine-Active Compounds by Streamlined Direct Bioautography

A direct bioautography has been used for the simultaneous determination of four estrogens [estrone (E1), 17β-estradiol (E2), estriol (E3), and 17α-ethinylestradiol (EE2)] and two xenoestrogens [bisphenol A (BPA) and 4-n-nonyl-phenol (NP)] in surface water and wastewater samples from a sewage treatment plant. After either direct application or a liquid–liquid extraction of the water samples, the qualitative and quantitative detection of estrogen-effective compounds was performed with a planar yeast estrogen screen. The limits of detection were different for each compound, due to the specific receptor binding of individual (xeno)­estrogens (1 ng/L to 15 μg/L). The mean recovery rate for all six substances at this ultratrace level was 88% [mean percent relative standard deviation (%RSD) of 17%, n = 3]. Over the whole procedure, precisions of three estrogens discovered in a wastewater sample were below 17%, n = 3. The identification of the detected bioactive compounds was performed by high-performance thin-layer chromatography–electrospray ionization mass spectrometry (HPTLC–ESI-MS) via the elution-head-based TLC–MS Interface. Whereas the estrogens E1 and E2 could always be detected in the influent of the treatment plant, E3 was detected occasionally. The concentrations of E1 and E2 ranged from 3 to 50 ng/L, and for E3 from 98 to 210 ng/L. EE2, BPA, and NP could not be detected at the given LOD. In every second surface water sample, E1 and E2 were detected, but not E3, EE2, BPA, and NP.