Application of quantitative salt iodine analysis compared with the standard method

Laboratory investigation of 50 iodated salt samples (from producers, households, markets etc) were studied at the Research Nuclear Medicine Building, Siriraj Hospital. Two methods for the determination of iodine in salt are herein described. The standard method as recommended by The Programme Against Micronutrient Malnutrition (PAMM) / The Micronutrient Initiative (MI)/ The International Council for Control of Iodine Deficiency Disorders (ICCIDD) was the iodometric titration method. The starch-KI salt iodine quantitative method was developed in our laboratory for validation purposes. This method is high in precision, accuracy, sensitivity as well as specificity. The coefficient of variation (%CV) for intra and inter assay was below 10. Iodine contents as low as 10 ppm, could be detected. The proposed starch-KI method offered some advantages: e.g. not complicated, easier to learn and easier to perform competently, could be applied for spot qualitative test and readily performed outside the laboratory. The results obtained by the starch-KI method correlated well with the standard method (y = 0.98x - 3.22, r = 0.99).