title: Mass dependence of calcium isotope fractionations in crown-ether resin chromatography.
abstract: Benzo 18-crown-6-ether resin was synthesised by the phenol condensation polymerisation process in porous silica beads, of which particle diameter was ca 60micro 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 epsilon is 3.1x10(-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.
authors.affiliation: Atox Co. Ltd, Kashiwa, Japan. fujiiya@mopera.net
authors.forename: Yasuhiko
authors.initials: Y
authors.lastname: Fujii
authors.forename: Masao
authors.initials: M
authors.lastname: Nomura
authors.forename: Tositaka
authors.initials: T
authors.lastname: Kaneshiki
authors.forename: Yoichi
authors.initials: Y
authors.lastname: Sakuma
authors.forename: Tatsuya
authors.initials: T
authors.lastname: Suzuki
authors.forename: Saori
authors.initials: S
authors.lastname: Umehara
authors.forename: Tadahumi
authors.initials: T
authors.lastname: Kishimoto
mesh_terms: D000327:Adsorption; D002127:Calcium Isotopes / Q000737:chemistry / Q000302:isolation & purification*; D005591:Chemical Fractionation; D002853:Chromatography, Liquid; D043844:Crown Ethers / Q000737:chemistry*; D013058:Mass Spectrometry; D008970:Molecular Weight; D012117:Resins, Synthetic / Q000737:chemistry*
chemical_list: D002127:Calcium Isotopes; D043844:Crown Ethers; D012117:Resins, Synthetic