DETERMINATION OF IODINE IN DIVERSE BOTANICAL AND DIETARY MATRICES BY PREIRRADATION COMBUSTION FOLLOWED BY NEUTRON-ACTIVATION ANALYSIS

The method chosen for determination of iodine in this investigation is an extension of an existing analytical technique to food samples whic h was developed for environmental samples. The method is based on pre- irradiation combustion of the sample to liberate iodine, trapping the iodine on charcoal, and quantitating the element by neutron activation analysis (NAA). Existing botanical and dietary reference materials we re used to check the validity of the method. Several mixed diet sample s with high fat content from the U.S. Total Diet Study and composites of cereals with both low and high iodine content were analyzed. This m ethod of pre-irradiation combustion followed by NAA has been shown to be a viable technique for the determination of iodine in dietary sampl es. However, with a detection limit of about 50 ng of iodine, large am ounts of sample (> 1 g) are typically required for each determination.