Abstract
Selenium (Se) contents of Japanese foodstuffs were measured by neutron activation analyses with the TRIGA-II reactor in Atomic Energy Research Laboratory, Musashi Institute of Technology. Freeze-dried samples (200-500mg) were irradiated in the pneumatic tube (thermal neutron flux, 1×1012n·cm-2·sec-1) for 10sec, and 77mSe produced was counted for 30sec in a γ-ray spectrometer system equipped with a Ge (Li) detector. Samples containing less than 0.05ppm Se and the processed foods of high salt contents were analyzed with radioactivities of 75Se after irradiation in the central symble (thermal neutron flux, 4×1012n cm-2 sec-1) for 5 hours, digestion in the HNO3-HClO4 mixture, and then purification by a precipitation process. Foodstuffs of animal origins contained more Se than those of plant origins. Se contents were as follows in the descending order: fish, meats, cereals, vegetables, and fruit. Daily per capital intaked of Se was in the range of 100-200μg, as calculated for and as found by analysis of composite diets representing ordinary Japanese meals.
