Application of a Novel Solid Silver Microelectrode Array for Anodic Stripping Voltammetric Determination of Thallium(I)

The article reports for the first time the application of a solid silver microelectrode array for the anodic stripping voltammetric determination of thallium(I) ions (Tl(I)). The microelectrode properties of the presented sensor were tested. The proposed solid metal microelectrode array is characterized by its eco-friendly nature due to the use of non-toxic electrode material. The advantage of this procedure is that no surface modification of the microelectrode was required. The optimization of the procedure for determining Tl(I) was performed. The experimental parameters (e.g., pH of supporting electrolyte, conditions of activation step, potential and time of deposition, effects of possible interferences) were investigated. The dependence of the thallium peak current on its concentration was linear in the range from 5 × 10^-10 to 1 × 10^-7 mol·L^-1 (deposition time of 120 s). The estimated detection limit was 1.35 × 10^-10 mol·L^-1. The repeatability of the procedure expressed as RSD% for a Tl(I) concentration of 2 × 10^-8 mol·L^-1 was 3.6% (n = 5). The proposed procedure was applied for determining Tl(I) in certified reference materials and for studying recovery in the environmental water sample. The obtained results indicated the possibility of an analytical application of the elaborated procedure in practice.