Radiochemical neutron activation analysis of Cs and Rb in geological samples using zeolite (clinoptilolite) chromatography and sodium tetraphenylborate precipitation

Three procedures for separating of Cs and Rb from geological samples were investigated. The fractional recovery was determined by radioactive tracers and by RNAA. In the first procedure 0.2 g of irrdiated sample is fused with Na₂O₂, acidified and passed through a clinoptilolite zeolite column. Cs and Rb were eluted with 7.5M HNO₃; chemical yields are in the range 93–98%. The second procedure is a supplement to the SUNDBERG and BOYNTON (1976) procedure; a previously discarded anion-exchanger effluent, containing Cs, Rb, Co, Na, etc., is passed through a clinoptilolite column. Cs and Rb are eluted with 7.5M HNO₃; yields are in the range of 82–94%. A third separation involves precipitation of Cs and Rb from the effluent and washings with sodium tetraphenylborate (NaBPh₄); yields are 64–83%.