Chlorination of bisphenol A: Non-targeted screening for the identification of transformation products and assessment of estrogenicity in generated water

• Bisphenol A (BPA) was completely removed in 10 min by chlorination in our conditions.
• A non-targeted approach was developed to reveal 21 transformation products.
• Brominated intermediates were reported for the first time for BPA chlorination.
• We evidenced a decrease of estrogenic activity after chlorination by ER-CALUX.

Besides the performance of water treatments on the removal of micropollutants, concern about the generation of potential biologically active transformation products has been growing. Thus, the detection and structural elucidation of micropollutants transformation products have turned out to be major issues to evaluate comprehensively the efficiency of the processes implemented for drinking water treatment. However, most of existing water treatment studies are carried out at the bench scale with high concentrations and simplified conditions and thus do not reflect realistic conditions. Conversely, this study describes a non-targeted profiling approach borrowed from metabolomic science, using liquid chromatography coupled to high-resolution mass spectrometry, in order to reveal potential chlorination products of bisphenol A (BPA) in real water samples spiked at 50 μg L−1. Targeted measurements first evidenced a fast removal of BPA (>99%) by chlorination with sodium hypochlorite (0.8 mg L−1) within 10 min. Then, the developed differential global profiling approach enabled to reveal 21 chlorination products of BPA. Among them, 17 were brominated compounds, described for the first time, demonstrating the potential interest of this innovative methodology applied to environmental sciences. In parallel to the significant removal of BPA, the estrogenic activity of water samples, evaluated by ER-CALUX assay, was found to significantly decrease after 10 min of chlorination. These results confirm that chlorination is effective at removing BPA in drinking water and they may indicate that the generated compounds have significantly lower estrogenic activity.