The separation of daughter nuclides from90Sr−90Y and140La−140Ba systems by thin-layer chromatographic methods

The separation of daughter nuclides in the carrier-free state from⁹⁰Sr?⁹⁰Y and¹⁴⁰Ba?¹⁴⁰La aqueous solution systems was performed by thin-layer chromatographic methods. (1) When a silica gel adsorbent and a developer of 1N NaCl, KCl, NH₄Cl, CaCl₂, SrCl₂ or BaCl₂ solutions was employed,⁹⁰Y and¹⁴⁰La were retained at the origin, while⁹⁰Sr and¹⁴⁰Ba advanced with the developer front. Addition of gypsum as binder to the silica gel prevented the separation of the¹⁴⁰Ba?¹⁴⁰La system, retaining both components at the origin. (2) When the¹⁴⁰Ba?¹⁴⁰La system was developed with water on a silica gel adsorbent containing 5% of gypsum, which was treated with various concentrations of nitric acid, the Rf value of¹⁴⁰La increased with the concentration of nitric acid used, reaching a maximum of 0.98 at 0.1 N. The Rf value then decreased on the further increase of the concentration of nitric acid. When the same process was applied to the⁹⁰Sr?⁹⁰Y system, there was no separation. The radiochemical purities of⁹⁰Y and¹⁴⁰La obtained in the above two ways were more than 99%.