'Bismuth extraction by aqueous two-phase system applied in the development of an alternative bismuth film electrode'

The bismuth extracted by an aqueous two-phase system in fusible plugs (BiSn alloy) used as safety valves in gas cylinders, was used in the development of a new bismuth film electrode (BiATPSFE). The aqueous two-phase system (ATPS) is an environment-friendly strategy for liquid-liquid extraction, in which polymers and salts dispersed in water are adopted. In order to evaluate the electrochemical response generated by BiATPSFE, square-wave anodic stripping voltammetry (SWASV) was applied to monitor the anodic peak current (Ipa) of cadmium (Cd2+) and lead (Pb2+). The voltammetric behavior of bismuth extracted by ATPS (Bi-ATPS) compared to the standard bismuth solution (Bi-STD), showed a similar voltammetric profile between Bi-ATPS and Bi-STD. A greater electrochemical response of the analytes was observed for BiATPSFE compared to bare electrode (glassy carbon electrode; GCE). The analytical method, adopting BiATPSFE, was validated and applied to lake water samples for the simultaneous determination of Cd2+ and Pb2+. The analytical method SWASV BiATPSFE can be adopted as a screening tool for Cd2+ and Pb2+ values that exceed the concentrations recommended by environmental legislation. This work demonstrates the ability of using an electrochemical sensor in an unconventional aqueous medium and the use of secondary sources for the modification of electrodes.