Abstrakt
The present invention provides a method for isolation of Ac from a mixture comprising radium, actinium and thorium comprising the following steps: a) a mixture of Ra/Ac/Th is loaded onto a separation column containing an anion exchanger based on a styrene cross-linked with divinylbenzene, wherein the content of the cross-linking agent is in the range of 5 to 50 %, preferably 8 to 16 %, in nitrate cycle, and eluted with a solution containing a mixture of 0.6 - 0.8M aqueous solution of nitric acid and methanol in volume ratio of nitric acid solution : methanol = 30 : 70 to 10 : 90, b) the eluate from the separation column is lead through the purification column containing an anion exchanger based on styrene cross-linked with divinylbenzene, wherein the content of the cross-linking agent is in the range of 5 to 50 %, preferably 8 to 16 %, in nitrate cycle, and eluted with a solution containing a mixture of 0.6 - 0.8M aqueous solution of nitric acid and methanol in volume ratio of nitric acid solution : methanol = 30 : 70 to 10 : 90, c) the eluate from step b), containing 226Ra, is isolated, preferably for recycling for repeated irradiation, d) Ac and/or Th is washed out from the separation and the purification column by elution solution containing 5 to 10M mineral acid and optionally at least one complexing agent, preferably the mineral acid is HNO3 and/or HCl.