Development of a simple analytical method for the determination of nitrite in waters using redox reaction and smartphone.

In this study, it was aimed to perform the colorimetric determination of nitrite in waters using the redox reaction of iodide in acidic conditions with smartphone. The simple redox reaction of iodide and nitrite in an acidic medium was used instead of the conventional nitrite methods based on the formation of azo dye. The quantitative relationship between the yellow-colored iodine formed because of the reaction and nitrite was determined by the digital image-based colorimetric method (DIC). In the optimal experimental conditions, detection limit and R values were determined as 0.02 mg/L and 0.9925, respectively. New method (Redox-DIC method) was validated by the standard Griess Method for nitrite in lake waters. The perfect recovery results (94-112%) were calculated for lake, river, tap, and spring waters spiked at different concentrations, and very good (< 5.0%) percent relative standard deviation values were recorded. Unlike conventional nitrite methods, organic reagents and solvents were not used in this method. The method is fast, simple, and low cost.