Determination of bisphenol S, simultaneously to bisphenol A in different water matrices or solely in electrolyzed solutions, using a cathodically pretreated boron-doped diamond electrode.

A simple, accurate, and environmentally friendly method for the simultaneous determination of the analog endocrine disruptors bisphenol S (BPS) and bisphenol A (BPA) was developed and validated. The determination was performed by square-wave voltammetry using a cathodically pretreated boron-doped diamond (BDD) as the working electrode, with 0.1 mol L HSO as the supporting electrolyte. Under optimized conditions, a wide linear working range (R = 0.999) from 0.20 to 80.0 mg L with a limit of detection (S/N = 3) of 0.060 mg L was attained for BPS. For BPA, a linear correlation (R = 0.992) was attained from 0.10 to 50.0 mg L, with a limit of detection of 0.030 mg L. As far as we could ascertain, these are the lowest limits of detection and the widest linear ranges in the literature for this determination. The method was applied to the simultaneous determination of BPS and BPA in real water samples, with minimum sample preparation processes (dilution and acidification only). Excellent recovery values were achieved, ranging from 95 to 99%. Additionally, the method was successfully applied to the monitoring of the electrochemical degradation (anodic oxidation) of BPS using a recirculating flow system fitted with a BDD anode. The decay of [BPS] with time was also checked by an HPLC method, with results statistically similar to those obtained by the proposed electroanalytical method. Hence, the proposed method is a reliable, greener, and low-cost alternative to monitor simultaneously BPS and BPA in aquatic matrices or only BPS in wastewater treatment processes.