2024 年 23 巻 p. 1-6
Prior to quantifying 90Sr using inductively coupled plasma-mass spectrometry (ICP-MS), its stable isobar, 90Zr, should be removed from analytical samples. To resolve this issue, a facile method was developed to selectively adsorb and extrude Zr from samples containing both Sr and Zr using a relatively inexpensive γ-cyclodextrin polymers. The saturated adsorption capacities of γ-cyclodextrin for Sr and Zr, calculated using the Langmuir adsorption isotherm model, are 0.0818±0.0025 and 7.41±0.13 mg/g, respectively, which indicates the feasibility of the selective removal of Zr from Sr/Zr mixtures. The observed difference in the adsorption capacity can be attributed to the diameter of γ-cyclodextrin being larger than that of the hydrated Zr ion but smaller than that of the hydrated Sr ion. As γ-cyclodextrin polymers are insoluble granules, they can be easily separated from the solid-liquid phase and then immersed in ethanol for extruding Zr from γ-cyclodextrin. Ethanol can then be evaporated, leaving less volume of the Zr residue. This strategy could reduce the preprocessing time for Sr quantification by ICP-MS and thus the radiation exposure of workers during the decommissioning work of a nuclear reactor.
