Rapid detection of iodine in iodised salt and iodised water essential in a program of iodine deficiency disorders control.

ABSTRACT

To determine and develop rapid on-site testing of iodine in salt and water samples and its use as field methods for monitoring and evaluation of the Iodine Deficiency Disorders (IDD) program. Methods: In order to monitor iodine in salt, the single bottle technique is recommended, utilizing SHMP (May & Baker), tapioca flour, KI and sodium azide. Secondly, to monitor iodine in water, the double bottle technique is employed and this utilizes 3N HCl as a substitute for SHMP to acidify flour, KI and sodium azide. Results: In salt, it is not positive until the colour starts to change from brown to black. In water, when it is positive reaching beyond an optimum level at 100-200 mg of iodine per litre, the colour starts to appear as faint blue and becomes darker blue as concentration of iodine increased. Discussion: Statistically, Spearman rank correlation co-efficient and the prediction method showed approximation of the two methods in estimation of iodine levels, indicating the interchangeability of the eyesight and it can be used in screening in place of the spectrophotometer. Conclusion: These techniques are cheap, simple and effective. This allows the monitoring kit to be beneficial and easy to use. These methods are ordinary and natural, and thus, in harmory with Thai culture and customs.