Simultaneous determination of arsenic and uranium by the diffusive gradients in thin films technique using Lewatit FO 36: Optimization of elution protocol

Diffusive Gradients in Thin-films technique for uranium monitoring along a salinity gradient: A comparative study on the performance of Chelex-100, Dow-PIWBA, Diphonix, and Lewatit FO 36 resin gels in the Scheldt estuary

“…The 1 ml of 1 M HEDPA at laboratory temperature and 1 ml of concentrated HNO3 at 70 °C were used for elution of Diphonix and Dow-PIWBA resin gels, respectively, as recommended by Drozdzak et al [17,45]. The 5 ml of 1M NaOH at 70 °C was used for elution of Lewatit FO 36 resin gels according to Smolíková et al [47]. The elution factors (fe) of 0.83 ± 0.02, 0.79 ± 0.04, 0.88 ± 0.01, and 0.85 ± 0.03 were used for calculation of the uranium mass accumulated on Chelex-100, Diphonix, Dow-PIWBA, and…”

“…This is especially apparent when DGTs are deployed in complex matrices such as seawater or when deployed for longer periods [41,42]. Therefore, Chelex-100 has been replaced by other binding phases (i.e., Diphonix [17,43], Dowex 2×8-6 400 [44], MnO2 [41], Metsorb [42], Dow-PIWBA [45], Spheron-Oxin [46], or Lewatit FO 36 [47]) more suitable for the selective determination of uranium. Their binding mechanisms are either based on chelation (Diphonix and Spheron-Oxin), sorption (Metsorb and MnO2), anion exchange (Dowex 2×8-400), or both sorption and anion exchange (Dow-PIWBA and Lewatit FO 36).…”

“…Lewatit FO 36,respectively) or their performance across the pH range typical for natural waters (pH = 4-8) [17,45,47,53]. In the present study, the DGTs utilizing these tested resins were deployed along the Scheldt estuary within four campaigns over the period 2014-2021 in order to find the most reliable DGT binding phase for uranium monitoring in the freshwater and marine environment.…”