Analysis of Iodide Ions Using Silver Cinnamate-Based Nanocomposites

The paper describes the preparation of silver-containing nanocomposites by thermolysis of silver cinnamate and their application for 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, the gravimetric analysis method, scanning electron microscopy, transmission electron microscopy, and energy-dispersive X-ray spectroscopy. Optimal conditions for modifying a cellulose carrier with nanocomposites in laboratory conditions were selected, ensuring high sensitivity of RIP to iodine and uniform and reproducible distribution of the reagent. A new gas extraction colorimetric technique for determining iodide ions in the range of 0.03–1.6 mg L−1 (limit of detection 0.01 mg L−1) was developed, allowing iodides to be determined in multicomponent objects such as food products, pharmaceuticals, and various water bodies with minimized sample preparation. The use of iron(III) as an oxidizing agent and the use of dynamic gas extraction ensure high selectivity and good analytical performance.