title: Separation of calcium-48 isotope by crown ether chromatography using ethanol/hydrochloric acid mixed solvent.
abstract: Benzo-18-crown-6 ether resin embedded in porous silica beads was synthesized and used as the packing material for chromatographic separation of (48)Ca isotope. The aim of the present work is to develop efficient isotope enrichment process for double β decay nuclide (48)Ca. To this end, ethanol/HCl mixed solvent was selected as the medium for the chromatographic separation. Adsorption of calcium on the resin was studied at different HCl concentrations and different ethanol mixing ratios in batch-wise experiments. A very interesting phenomenon was observed; Ca adsorption is controlled not by the overall HCl concentration of the mixed solvent, but by the initial concentration of added HCl solution. Calcium break-through chromatography experiments were conducted by using 75v/v% ethanol/25v/v% 8M HCl mixed solvent at different flow rates. The isotope separation coefficient between (48)Ca and (40)Ca was determined as 3.8×10(-3), which is larger than that of pure HCl solution system. Discussion is extended to the chromatographic HETP, height equivalent to a theoretical plate.
authors.affiliation: Tokyo Institute of Technology, Research Laboratory for Nuclear Reactors, O-okayama, Meguroku, Tokyo 152-8550, Japan.
authors.forename: Shin
authors.initials: S
authors.lastname: Okumura
authors.affiliation: Osaka University, Research Center for Nuclear Physics, Ibaraki, Osaka 567-0047, Japan.
authors.forename: Saori
authors.initials: S
authors.lastname: Umehara
authors.affiliation: Tokyo Institute of Technology, Research Laboratory for Nuclear Reactors, O-okayama, Meguroku, Tokyo 152-8550, Japan. Electronic address: yfujii@nr.titech.ac.jp.
authors.forename: Yasuhiko
authors.initials: Y
authors.lastname: Fujii
authors.affiliation: Tokyo Institute of Technology, Research Laboratory for Nuclear Reactors, O-okayama, Meguroku, Tokyo 152-8550, Japan.
authors.forename: Masao
authors.initials: M
authors.lastname: Nomura
authors.affiliation: Tokyo Institute of Technology, Research Laboratory for Nuclear Reactors, O-okayama, Meguroku, Tokyo 152-8550, Japan.
authors.forename: Toshitaka
authors.initials: T
authors.lastname: Kaneshiki
authors.affiliation: Tokyo Institute of Technology, Research Laboratory for Nuclear Reactors, O-okayama, Meguroku, Tokyo 152-8550, Japan.
authors.forename: Masaki
authors.initials: M
authors.lastname: Ozawa
authors.affiliation: Osaka University, Graduate School of Science, Toyonaka, Osaka 567-0043, Japan.
authors.forename: Tadafumi
authors.initials: T
authors.lastname: Kishimoto
mesh_terms: D000327:Adsorption; D002127:Calcium Isotopes / Q000302:isolation & purification*; D002853:Chromatography, Liquid; D043844:Crown Ethers / Q000737:chemistry*; D000431:Ethanol; D006851:Hydrochloric Acid; D012822:Silicon Dioxide / Q000737:chemistry*; D012997:Solvents
chemical_list: D002127:Calcium Isotopes; D043844:Crown Ethers; D012997:Solvents; D000431:Ethanol; D012822:Silicon Dioxide; D006851:Hydrochloric Acid
keywords: Benzo-18-crown-6 ether; Ca-48; Crown ether; Double beta decay; HETP; Isotope separation