Wijs solution is primarily used in analytical chemistry for the determination of the iodine value of fats and oils. The iodine value is a critical parameter that indicates the degree of unsaturation in fatty acids, which is essential for assessing the quality and stability of edible oils, fats, and related products. By reacting with the double bonds in unsaturated fatty acids, Wijs solution helps quantify the amount of iodine absorbed, providing insights into the oxidative stability and shelf life of the product. This application is particularly important in the food industry for quality control, as well as in research and development for formulating products with desired properties. Additionally, it is used in the production of biodiesel to evaluate the suitability of feedstocks based on their fatty acid composition.