Photolysis Kinetics, Mechanisms, and Pathways of Tetrabromobisphenol A in Water under Simulated Solar Light Irradiation

Abstract

The photolysis of tetrabromobisphenol A (TBBPA) in aqueous solution under simulated solar light irradiation was studied under different conditions to find out mechanisms and pathways that control the transformation of TBBPA during photoreaction. Particular attention was paid to the identification of intermediates and elucidation of the photolysis mechanism of TBBPA by UPLC, LC/MS, FT-ICR-MS, NMR, ESR, and stable isotope techniques ( 13 C and 18 O). The results showed that the photolysis of TBBPA could occur under simulated solar light irradiation in both aerated and deaerated conditions. A magnetic isotope effect (MIE)-hydrolysis transformation was proposed as the predominant pathway for TBBPA photolysis in both cases. 2,6-Dibromophenol and two isopropylphenol derivatives were identified as photooxidation products of TBBPA by singlet oxygen. Reductive debromination products tribromobisphenol A and dibromobisphenol A were also observed. This is the first report of a photolysis pathway involving the formation of hydroxyl-tribromobisphenol A.

Recent advances in the analysis of TBBPA/TBBPS, TBBPA/TBBPS derivatives and their transformation products

“…For the cleanup of nonwater samples, the most widely used methods were gel permeation chromatography (GPC), activated silica gel column, and Florisil [6,31]. Commercially available SPE tubes also have good applicability for the cleanup of residues extracted from soil, sediment, [14][15][16][17][18][19][20][21][22][23][24] and biota samples [32]. However, severalcommercial cartridges showed poor recoveries because target analytes were strongly absorbed by the sorbents of the cartridges and could not be adequately eluted [10].…”

“…4A). For instance, solar light could induce the photolysis of TBBPA as the result of magnetic isotope effect hydrolysis, singlet oxygen oxidation, and reductive debromination [16]. Under these conditions, hydroxyl tribromo-BPA (HtriBBPA) emerges as a direct photolysis product of TBBPA and various products are formed sequentially [18].…”

“…H2O was applied as an exposure matrix under simulated solar light irradiation. The isotopic proportion of the peak or fragment ion was monitored based on MS and metabolites, including tribromo-BPA, dibromo-BPA, and monobromo-BPA, were identified [16]. By using a GC-ion trap mass spectrometer, Bastos et al used KMnO4 as an oxidative agent to investigate the rates of TBBPA degradation in water systems (Fig.…”

“…Cumulative evidence suggests that abiotic degradation, including photolysis, oxidation, reduction, and radical reactions, are involved in TBBPA degradation [14][15][16]. As compared with abiotic reactions, biotic reactions are considered to be the main transformation pathways of TBBPA and can result in the presence of unknown brominated substances in environmental compartments [8,17,18].…”

“…As compared with abiotic reactions, biotic reactions are considered to be the main transformation pathways of TBBPA and can result in the presence of unknown brominated substances in environmental compartments [8,17,18]. With the development of analytical methods based on MS, various transformation products of TBBPA have been observed [8,9,[15][16][17][18][19][20][21]. However, there has been little or no documented investigation concerning the degradation of TBBPA derivatives.…”