spectrophotometric determination of iodate based on ultrasound-assisted emulsification microextraction using deep eutectic solvent

Iodine is an essential element of the human body and is a fundamental part of the thyroid hormones that are essential to the development and differentiation of all cells. iodine deficiency is an important public health issue for populations throughout the world, which can lead to developmental delays and other health problems (i.e., hypothyroidism, brain damage, and cretinism). the common method to prevent these iodine deficiency disorders is salt iodization due to its extensive consumption . iodate is added to iodized salt as a source of iodine to prevent iodine deficiency disorders in many countries. thus, iodate quantification in iodized edible salt is of great importance [1]. in 2021, caleb et al. used smartphone digital image colorimetry combined with the solidification of floating organic drop-dispersive liquid-liquid microextraction for the determination of iodate in table salt. the method had a limit of detection of 0.2 µg g−1. in 2022, gupta et al. used dispersive liquid-liquid microextraction and diffuse reflectance-fourier transform infrared spectroscopy for iodate determination in salt and food samples. the method had a limit of detection of 4.4 µg kg−1 [3]. in this study, an ultrasound-assisted deep eutectic solvent-based liquid-phase microextraction method combined with spectrophotometry has been developed for the determination of iodate. the method is based on the oxidation of iodide to iodine by iodate in the acidic media. the produced iodine reacts with the excess iodide to form triiodide ions. triiodide is extracted into the des phase (tetrabutylammonium chloride: decanoic acid, 1:3 molar ratio) in the presence of ctab and was determined by a uv-vis spectrophotometry at 355 nm. under the optimized conditions, the method provided a detection limit of 17 µg l-1 and an enrichment factor of 250. the relative standard deviation at 140 µg l-1 concentration of iodate (n = 6) was found to be 2.4%. the method was applied for the determination of iodate in iodized salts.