PRECONCENTRATION OF NI-63 IN SEA-WATER FOR LIQUID SCINTILLATION-COUNTING

A preconcentration procedure for enriching Ni-63 from sea water for me asurement by liquid scintillation counting (LSC) was established. Ni-6 3 was first enriched by adsorption on hydrous magnesium oxide. The pre cipitate was collected and dissolved in concentrated HCl. Ni-63 was se parated from the HCl solution by extraction with diethyldithiocarbamat e in chloroform followed by back-extraction into AU3+ solution. Finall y, Ni-63 in the Au3+ solution was extracted with dimethyl glyoxime in xylene and the organic phase containing Ni-63 was withdrawn for LSC. T he optimum conditions of the above preconcentration procedure were inv estigated by means of an r-emitter, 65Ni, instead of Ni-63, which is a weak beta-emitter, as a radioactive tracer- The preconcentration proc edure was applied in conjunction with LSC to the an lysis of a Ni-63-c ontaining simulated sea-water sample and was found to be feasible and practical.