Determination of Iodine in Edible Salt Added Potassium Iodate by Ultraviolet Spectrophotometry

According to the ultraviolet absorption spectra of iodine,iodide ion and triiodide ion, a method for determination of iodine in edible salt added potassium iodate was proposed. In the medium of HCl with pH 2.4, 0.01?mol/L KI, 1 mol potassium iodate may be quantitatively converted into 3?mol I 3-.By measuring the absorbance of I 3- at 288 or 350 nm, quantity of iodine in edible salt can be calculated. A recovery percent of this method was found to be 96.8?%～102.6?%. Two samples of edible salt purchased from market were analyzed. The results were satisfactory.