Potassium iodate in table salt can be spectrophotometrically determined at two well defined UV absorption maxima (288 and 352 nm), after being converted to I3- by reaction with iodide in the presence of phosphoric acid Calibration curves with slopes of 7.320 x 10(4) and 1.103 x 10(5) L mol-1 cm-1 were obtained at 352 and 288 nm, respectively, at 22 °C. Typical results of 37.39 (±0.15) and 63.67 (±0.16) mg KIO3 per kg of salt were obtained with samples of 0.15-0.21 g, comparable with results from a standard but less precise iodometric titration of large samples (20-50 g). The method has been found adequate for checking homogeneity of iodine distribution in table salt, as small weighed samples are normally required.
iodized salt; spectrophotometry; salt; iodate
