مشخصات پژوهش

In this study, a fast and simple method has been developed for the determination of nitrite in different aqueous samples. The method, which can be applied for on-site as well as off-site analyses, is based on the reaction of nitrite with potassium iodide in an acid medium to liberate triiodide ions. These liberated triiodide ions react with starch adhesive to form a dark blue complex, which is quantified by digital imaging using an ordinary smartphone and a freely available mobile application. Image analysis was done in the RGB color space, and the B-channel values were used to obtain the analytical signal. Under the optimum conditions, the method showed a linear range of 0.05–1 mg/L and a detection limit of 0.013 mg/L. The relative standard deviation for the determination of 0.5 mg/L nitrite was found to be 2.2% (n = 6). The results obtained using the proposed method were evaluated by comparing them to those obtained by a commercial UV-Vis spectrophotometer and also by analyzing spiked samples to calculate recovery percentages.