Iodine Content of Branded Iodized Nigerian Table Salt: Ten Years After USI Certification

The present study estimated iodine content of five common branded iodized salts in Nigerian markets to ascertain compliance with Universal Salt Iodization (USI) at retail level after ten years. The study also derived iodine formula for estimating iodine content in salt for easy nutrition applications. Qualitative detection of iodide ions in salts were by tetraoxosulphate (VI) acid, oxidation, and silver nitrate tests. Iodate ions in 20% iodized salt solution was by iodometric titration. An iodine formula for iodine content was derived from the average titer volume and titrimetric equations for iodate ions. According to the results, only oxidation method was able to detect iodide ions in all salt samples. The derived Iodine formula was 𝐼 2𝑆𝐴𝐿𝑇 = 𝑉 𝑁𝑎2𝑆2𝑂3 𝑋 𝑀 𝐼 , (where, I 2SALT is amount of iodine in ppm, V Na2S2O3 is volume of thiosulphate and M I is iodine factor = 10.58333  𝑝𝑝𝑚 / 𝑚𝑙 ). Based on the derived iodine formula, the amount of iodine in the assessed branded salts ranged from 38.45 to 49.57 ppm with an average of 43.71 ppm. The present study revealed continuous compliance of 30 ppm iodine in Nigerian retail common salts. The derived iodine formula is simple, self-explanatory and useful for iodine estimates using iodometric titration in laboratories. Keywords : Branded iodized salts, iodine, iodine formula, iodometric titration,