DETECTION OF IRRADIATION TREATMENT OF DATES USING THERMOLUMINESCENCE OF MINERAL CONTAMINANTS

Four types of dates have been studied for the detection of irradiation treatment using thermoluminescence (TL) from the mineral contaminants adhering to the dates. The results were normalized using a re-irradia tion step to improve identification method. These date samples were ei ther irradiated using Co-60 gamma rays to 1.0 kGy or electron accelera tor to 0.75, 2.2 and 3.9 kGy. The difference in the intensity of TL gl ow curve for minerals separated from the irradiated samples as compare d to unirradiated samples makes it possible to distinguish irradiated dates from unirradiated dates. After normalization step, the ratio of first glow curve to the second glow curve is more than 1.0 for all irr adiated samples and much less than 0.1 for un-irradiated samples makin g detection of irradiated dates more reliable.