Determination of iodine in Libyan food samples using epithermal instrumental neutron activation analysis.

Epithermal instrumental neutron activation analysis (EINAA) has been used to determine the iodine content of many individual food materials that constitute the typical Libyan diet. The selected samples include different varieties of local and imported foods such as wheat and barley products, rice, bread, legumes such as chick peas and lentil, table salt, and commonly used spices, including thyme and fenugreek. Both conventional and anticoincidence gamma-ray spectrometry techniques have been employed. Epithermal INAA in conjunction with anticoincidence counting has been found to provide the most reliable results. For quality control purposes, a number of NIST biological reference materials were analyzed. The range of daily dietary intake has been calculated as 100-180 microg of iodine per day, which is within the recommended range. Bread was identified as a significant source of iodine in the Libyan diet, as it contributed 99 microg/d.