Determination of selenium, arsenic, iodine and bromine in fish, plant and mammalian oils by cyclic instrumental neutron activation analysis

The concentrations of arsenic, selenium, iodine and bromine in a series of fish, plant and mammalian oils have been determined by cyclic instrumental neutron activation analysis (CINAA). Crude fish oils contain between 0.047 and 0.151 μg Se g −1 , 2.36–14.5 μg As g −1 , 2.36–9.63 μg Br g −1 and 0.97–4.76 μgI g −1 . Seal oil contains the same four elements, but at levels below the lower end of the fish oil ranges. Iodine, bromine and arsenic were not detected in rape‐seed or soybean oils and the concentration of selenium varied from < 0.010 to 0.042 μg g −1 . The levels of selenium, iodine and bromine are reduced markedly by hydrogenation of the menhaden oils. The CINAA method yielded results which were in agreement with pub‐lished values obtained by other methods. The technique was rapid, requiring minimal sample manipulation, and was essentially free from interferences.