2021 年 56 巻 1 号 p. 5-16
Since the specific activity of uranium is very low, it is not easy to analyze numerous liquid samples containing a small amount of uranium, and it is effective to improve the operational efficiency by pre-screening the uranium using a simple method. We expect that the proposed method, wherein uranium in a liquid sample is adsorbed on graphene oxide, collected by a membrane filter and analyzed by X-ray fluorescence, is suitable for screening such a liquid sample containing uranium. However, graphene oxide comprises small particles that clog the membrane filter during collection. When sodium perchlorate is added to the sample, the salinity concentration increases and graphene oxide aggregates, rendering the filtration process easier. In this study, it was confirmed that the addition of sodium perchlorate to the sample shortened the graphene oxide collection time and did not affect the fluorescent X-ray analysis results. The lower limit of uranium detection by this method is approximately 0.42 ng mL–1, which is equals to 0.042 mBq cm–3 when converted to the radioactivity concentration under conservative conditions. This is approximately 1/500 of the effluent standard value for uranium in drainage water.
