Optimal conditions for identifying 80Br and 128I in health food Angelica keiskei using rapid epithermal neutron activation analysis

This study presents an optimal rapid epithermal neutron activation analysis (ENAA) technique, using a 1 mm Cd filter in reactor neutron flux, to analyze 80Br and 128I in the roots, stems, and leaves of health food Angelica keiskei (AK). Various sample weights of lichen (IAEA-336) for each portion of AK, under various periods of irradiation and counting, were used to optimize the elemental analysis. Selecting the analytical conditions depends on the minimum detectable concentration (MDC), required sensitivities and the quantitative accuracy of Br and I elements. These findings imply that the MDCs of Br and I, measured under 10 min activation and 5 min counting followed by 10 min decaying, using 350 mg of lichen are ideal for elemental analysis. Moreover, each portions of AK were analyzed under optimal conditions. The elemental concentrations of Br, Cl, I, Mg, Mn and Na and their implications are discussed.