Carbon thick sheet potentiometric sensor for selective determination of silver ions in X-ray photographic film

Abstract

Innovative screen-printed electrode (SPE) based on Alizarin Red S (ARS) for Ag (I) ion determination was developed. The ionophore content was varied and optimized which indicated that the ink incorporating 30 mg of Alizarin Red S reflects the best experimental performance exhibiting monovalent Nernstian slope value of 59.95 mV decade−1 over a considerable spacious concentration range from 5.0 × 10−7 to 1.0 × 10−2 mol L − 1 with a lower detection limit value of 5.0 × 10−7 mol L − 1. Additionally, the developed sensor stable for more than 112 days without any significant drift in potential exhibited a fast response time (7 s). The interaction between Ag (I) ions and ARS ionophore at the electrode surface was investigated and elucidated using scanning electron microscopy (SEM), energy dispersive X-ray analysis (EDX) and FTIR spectra measurement. The proposed sensor achieved constant potentiometric response in pH range of 4–8 and thermally stable to 50 ͦ C. The developed sensor indicates discriminating capability toward Ag (I) ions with regard to most common transition metal ions. The new developed sensor used for determination of Ag (I) ion in x-ray photographic film and can be applied as indicator electrode in precipitation titrations. Furthermore, the method was validated according to IUPAC recommendation parameters.