Mass dependence of calcium isotope fractionations in crown-ether resin chromatography
Mass dependence of calcium isotope fractionations in crown-ether resin chromatography
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DOI：
10.1080/10256016.2010.488801
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发表时间：
2010-01-01
影响因子：
1.3
通讯作者：
Kishimoto, Tadahumi
中科院分区：
文献类型：
--
作者：
Fujii, Yasuhiko;Nomura, Masao;Kishimoto, Tadahumi
采用苯酚缩聚法合成了粒径约60μm的多孔硅珠，采用苯酚缩聚法合成了苯并18-冠-6-醚树脂。将合成的树脂装填于玻璃柱中进行钙吸附色谱分析。对流出物进行分级采样，并通过热电离质谱仪测量 (42)Ca、(43)Ca、(44)Ca 和 (48)Ca 与 (40)Ca 的同位素丰度比。在钙吸附色谱图的前边界处观察到较重的钙同位素的富集。采用三同位素图法分析了钙同位素相互分离的质量依赖性。三同位素图的斜率表示相关同位素对的相互分离系数的相对值。结果显示出正常的质量依赖性；同位素分馏与减少的质量差 (M - M')/MM' 成正比，其中 M 和 M' 分别是重同位素和轻同位素的质量。质量依赖性阐明同位素分馏源自分子振动。对于 (40)Ca 和 (48)Ca 对，观察到的分离系数 e 为 3.1 x 10(-3)。讨论了冠醚树脂富集(48)Ca的产率与分离系数和理论塔板高度的函数关系。
Benzo 18-crown-6-ether resin was synthesised by the phenol condensation polymerisation process in porous silica beads, of which particle diameter was ca 60 mu Calcium adsorption chromatography was performed with the synthesised resin packed in a glass column. The effluent was sampled in fractions, and the isotopic abundance ratios of (42)Ca, (43)Ca, (44)Ca, and (48)Ca against (40)Ca were measured by a thermo-ionisation mass spectrometer. The enrichment of heavier calcium isotopes was observed at the front boundary of calcium adsorption chromatogram. The mass dependence of mutual separation of calcium isotopes was analysed by using the three-isotope-plots method. The slopes of three-isotope-plots indicate the relative values of mutual separation coefficients for concerned isotopic pairs. The results have shown the normal mass dependence; isotope fractionation is proportional to the reduced mass difference, (M - M')/MM', where M and M' are masses of heavy and light isotope, respectively. The mass dependence clarifies that the isotope fractionations are originated from molecular vibration. The observed separation coefficient e is 3.1 x 10(-3) for the pair of (40)Ca and (48)Ca. Productivity of enriched (48)Ca by crown-ether-resin was discussed as the function of the separation coefficient and the height equivalent to the theoretical plate.