Observation of cerium isotope fractionation in ion-exchange chromatography of Ce(III)-malate complex.
The cerium isotope fractionation between Ce(III)-malate complex in aqueous solution and cerium ions in a cation-exchange resin was conducted by displacement chromatography. The pH and the chemical composition of the eluent were optimized for maintaining the self-sharpening band boundaries and the 21 m chromatographic migration of the Ce band underwent. Graphite slurry was coated on the tantalum filament prior to sample loading for reducing the isobaric interferences in cerium isotopic ratio determination by mass spectrometry. From the experimental results, it was found that the heavier isotope was enriched in the front boundary part of the cerium adsorption band, which meant that the heavier isotope was preferentially fractionated into the Ce3+ malate complex rather than simply hydrated Ce3+ ions. The isotope separation coefficient for the 136Ce/140Ce and 142Ce/140Ce was 5.2 x 10(-5) and -1.9 x 10(-5), respectively, at 298 K.
Zhang
Yong-Hong
YH
Department of Chemistry, Sophia University, 7-1 Kioi-cho, Chiyoda-ku, Tokyo 102-8554, Japan. yo-zhang@sophia.ac.jp
Gunji
Shinichiro
S
Nomura
Masao
M
Fujii
Yasuhiko
Y
Oi
Takao
T
D002564:Cerium Isotopes / Q000737:chemistry*; D002852:Chromatography, Ion Exchange / Q000379:methods*; D006863:Hydrogen-Ion Concentration; D008293:Malates / Q000737:chemistry*; D013058:Mass Spectrometry
D002564:Cerium Isotopes; D008293:Malates; C030298:malic acid