The use of a palladium film electrode (PdFE) as an alternative electrode for the determination of thallium (Tl+) and lead (Pb2+) in water samples by anodic stripping voltammetry is proposed. Preliminary studies of the influence of the substrate were performed on the electrochemical behavior of PdFE prepared ex situ. Using a silver solid amalgam electrode as substrate (AgSAE), the effect of several parameters such as potential and deposition time, composition and pH of supporting electrolyte on the analytical response of PdFE for Tl+ by differential pulse anodic stripping voltammetry (DPASV) was initially investigated. Under best experimental conditions of deposition potential of −1.2 V and deposition time of 300s the analytical curve was linear in the Tl+ concentration from 3.0 to 100.0 µg L−1 with a relative standard deviation (RSD) <2.0%. The limit of detection (LOD) and limit of quantification (LOQ) were 0.89 µg L−1 and 2.96 µg L−1, respectively. The PdFE was successfully applied for the determination of Tl+ in water samples. Moreover, this electrode showed promising as a sensor for the simultaneous determination of Tl+ and Pb2+ and as a suitable alternative to the mercury electrode.
Keywords:
palladium film electrode; silver solid amalgam electrode; Tl+ and Pb2+; differential pulse anodic stripping voltammetry (DPASV)
