Widespread use of bisphenols (BPs) in our daily life results in their elevated concentrations in waters and the need to study their environmental impact, which demands reliable and robust measurement techniques. Diffusive gradients in thin films (DGT) is an in situ passive sampling approach which provides time-integrated data. In this study we developed a new methodology, based on DGT with activated charcoal (AC) as a binding agent, for measuring three BPs (BPA, BPB, and BPF) which incorporated and tested its performance characteristics. Consistent elution efficiencies were obtained using methanol when concentrations of BPs were low and a methanol-NaOH mixture at high concentrations. The diffusion coefficients of BPA, BPB, and BPF in the diffusive gel, measured using an independent diffusion cell, were 5.03 × 10(-6), 5.64 × 10(-6), and 4.44 × 10(-6) cm(2) s(-1) at 25 °C, respectively. DGT with an AC binding gel had a high capacity for BPA, BPB, and BPF at 192, 140, and 194 μg/binding gel disk, respectively, and the binding performance did not deteriorate with time, up to 254 d after production. Time-integrated concentrations of BPs measured in natural waters using DGT devices with AC gels deployed in situ for 7 d were comparable to concentrations measured by an active sampling method. This study demonstrates that AC-based DGT is an effective tool for in situ monitoring of BPs in waters.

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Desorption/adsorption of bisphenols (BPs) in soils affects their mobility and availability. However, the kinetics of these processes have not been well studied, due to the lack of appropriate means of measurement. Diffusive gradients in thin-films (DGT) technique can assess kinetic processes in soils and have recently been developed for measuring three BPs (BPA, BPB and BPF). DGT was deployed for 2.5h to 20 d in five soils with different soil properties. Non-linear increase in mass accumulation by DGT with time indicated poor resupply of BPs from soil solid to solution phase. By fitting the data with DIFS (DGT-induced fluxes in soils) model, values for the labile partition coefficient (K), response time (t) and rates of exchange (k and k) of BPs between soil solid and solution phases were obtained. The derived values of K showed that most of the BPs in the soil could participate in labile exchange. Average response times of 1-2h implied that the supply of BPs to DGT was limited by their desorption rate. Soils with more binding sites (higher DOM, CEC and Fe oxides) could resupply BPs more quickly, highlighting the danger of just considering partition effects.