New Mixed Bromine/Chlorine Transformation Products of Tetrabromobisphenol A: Synthesis and Identification in Dust Samples from an E-Waste Dismantling Site

Abstract

The large-scale production and usage of tetrabromobisphenol A (TBBPA) and its analogues have caused widespread contamination, raising concern about their potential endocrine disruption effects on both humans and ecosystems. In the present study, debromination and unknown mixed bromine/chlorine transformation products of TBBPA (X-BBPA) were screened in dust samples from an e-waste dismantling site. Five monochloro products (2-chloro-2′,6,6′-TriBBPA, 2-chloro-2′,6-DiBBPA, 2-chloro-2′,6′-DiBBPA, 2-chloro-2′-MoBBPA, and 2-chloro-6-MoBBPA) and two dichloro products (2,2′-dichloro-6,6′-DiBBPA and 2,2′-dichloro-6-MoBBPA) were successfully synthesized and structurally identified. TBBPA and its transformation products were detected by comparison of their mass spectra and retention times with those of synthetic standards. The mean concentration of X-BBPA was 1.63 × 104 ng/g in e-waste dismantling workshop dust samples based on dry weight, which was at a similar level to TBBPA. However, it was 1 order of magnitude lower than the concentrations of the debromination congeners. Thus, both debromination and chlorine–bromine exchange may be important reactions during the thermal processing of e-waste. The results on mixed chlorinated/brominated TBBPA transformation products provided new insights into TBBPA transformation. The elevated levels of the transformation products of TBBPA suggested that these products should be targeted to avoid underestimation of possible health risks.