Abstract
241Am is present in the environment as a consequence of nuclear power plant accidents, authorized discharges from reprocessing plants, or atmospheric weapons tests. Compared with the intensive studies of plutonium in the environment, few investigations of 241Am have been performed. From a radiological health point of view, it is important to study the distribution of 241Am and its behavior in the environment because this radionuclide will be a major contributor to the dose to the public, considering the fact that the concentration of 241Am will continuously increase in the environment and to reach its maximum activity in the middle of 21st century. On the other hand, 241Am is useful tracer in understanding biogeochemical processes in the marine environment because of its high particle affinity.
We report a rapid and simple SF-ICP-MS analytical method for 241Am in sediment samples. A selective CaF2 co-precipitation procedure followed by an extraction chromatography separation and purification using Eichrom TRU resin was employed to remove the major matrix and pre-concentrate 241Am. Because of the short-life of 241Am, effort was made to improve the sensitivity of SF-ICP-MS using a high efficiency sample introduction system. The achieved detection limit of 0.3 fg/g (0.04 mBq/g) is extremely low, which allowed the determination of 241Am for low-level environmental samples. The developed method was validated by the analysis of ocean sediment reference material (IAEA-368) with satisfactory result, and will be applied to the study of 241Am distribution in marine environment.
