화학공학소재연구정보센터
Separation Science and Technology, Vol.34, No.6-7, 1133-1144, 1999
Fractionation of lithium isotopes in ion exchange chromatography with titanium phosphate exchanger
Ion exchange chromatography of lithium was carried out to study the lithium isotope effect in an aqueous ion-exchange system, using titanium phosphate exchangers granulated with polyvinyl chloride or an inorganic binder. The sample granulated with PVC showed significant isotope fractionations when a 0.05 M (NH4)(2)CO3 solution was used as an eluent. The lighter isotope Li-6 was preferentially fractionated into the exchanger phase. The isotope separation factor was roughly evaluated as 1.007, which is smaller than that (1.017) obtained by batch experiment in a preceding paper. The smaller separation factor could be explained by the fact that the number of sites effective for Li+ exchange is less than the number evaluated from the ion exchange capacity. The exchanger granulated with an inorganic binder did not show lithium isotope fractionation in spite of its large capacity for retention of lithium.