Determination of iodide ions using reactive indicator paper modified with silver cinnamate-based nanocomposites

Abstract

Solving a wide range of chemical analysis problems often requires the use of sorption and extraction processes as methods for separating, concentrating, identifying, and quantifying analytes. This circumstance leads to an ongoing search for new, easy-to-use sorbents with improved properties. A wide variety of substances can be used as such sorbents, including metal-polymer nanocomposites, which have recently attracted increasing interest from researchers due to their combination of the exceptional physicochemical properties of metal nanoparticles with the mechanical, film-forming, and other beneficial properties of polymers. Among the wide variety of metal-polymer nanocomposites, materials based on silver nanoparticles stand out. This paper describes the preparation of silver-containing nanocomposites by thermolysis of previously synthesized silver cinnamate, as well as their use in the manufacture of reactive indicator paper (RIP) sensitive to iodine. The composition, structure, and properties of the obtained materials were studied using IR spectroscopy, X-ray diffraction, scanning electron microscopy, transmission electron microscopy, and energy-dispersive X-ray spectroscopy. Optimal conditions for modifying the cellulose carrier with nanocomposites in laboratory conditions were selected, ensuring high sensitivity of the RIP to iodine, as well as uniform and reproducible reagent distribution. A new gas extraction colorimetric method for determining iodide ions in the range of 0.03–1.6 mg/L (detection limit 0.01 mg/L) was developed. This method enables the determination of iodides in multicomponent samples such as food products, pharmaceuticals, and various water bodies with minimal sample preparation. The use of iron (III) as an oxidizing agent and dynamic gas extraction ensures high selectivity and good analytical characteristics of the proposed method. Furthermore, this method enables the determination of trace amounts of iodides in the presence of high chloride and bromide levels, in colored and turbid solutions, which is particularly important when analyzing halides. Certainly, the advantage of this method over others lies in its cost-effectiveness and rapidity.