Nitric acid concentration strongly influences low level uranium determination on PEDOT-PSS coated glassy carbon electrodes

Abstract

Understanding the parametric optimization and addition of modifications in existing techniques are the keys to successful research in the analytical sciences. The present study reports an electroanalytical technique by modifying an electrode with PEDOT-PSS and adjusting the analyte solution to lower acidity (0.05 M) levels. The proposed methodology achieved a detection limit of 1.24 ppb of uranium, which is far below the available concentrations of uranium in seawater; the WHO permissible limit for uranium in drinking water; and the allowed disposal limit for uranium in radioactive waste solutions. Redox characteristics and speciation analysis supported by theoretical prediction helped to understand the basic mechanism which lay behind the achievement of such low detection limits. The technique was successfully employed for uranium determination in real water samples and the results were validated by another independent technique (ICP-MS).