PubMed · 4374015
The source did not provide an abstract. Follow the original record for more information.
Explore connections, maps & timelines
J R Mallard. 1972. The radionuclide imaging process.. https://pubmed.ncbi.nlm.nih.gov/4374015/
Cite the original work for its findings. Save a collection to share your selection of sources.
KEEP EXPLORING
Isotope effects of cerium were observed in malate and lactate complex formations during the long-distance displacement chromatographic processes at 313 K. Heavier isotopes were found fractionated in the frontal edges of the Ce adsorption bands in both the systems, registering a preference of the heavier isotopes for the Ce(III) complexes in the solution phase over the simply hydrated Ce(III) ions in the resin phase. The fractionation coefficients epsilon for the 136Ce/140Ce, 138Ce/140Ce and 142Ce/140Ce isotopic pairs were 7.1 x 10(-6), 5.2 x 10(-6) and -2.1 x 10(-6) for the malate system, and 4.8 x 10(-6), 4.5 x 10(-6) and-2.6 x 10(-6) for the lactate system, respectively. They all show the mass-dependent law if the deviation of epsilon for the 138Ce/140Ce pair was considered merely due to the isobaric interference in Ce isotopic ratio measurements, suggesting the molecular vibration, rather than the nuclear field shift, mainly contributes to the Ce isotope effects in the complex formation systems. The absolute values of epsilon between the two systems are comparable, suggesting no instinct difference in structural properties between Ce malate and lactate complexes involved.
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.
Explore the source record for details and available documents.