Separation and purification of 131I from tellurium material using ion exchange for preparing tetra-butyl ammonium iodide (131I)

A comparison of the distribution coefficients (Kd) of tellurium and iodine-131 (131I) between hydrochloric acid of various concentrations (without and in presence of 0.1 M thiourea) and the cation exchange resin (Dowex50WX8) was studied. The Kd of tellurium and 131I at different concentrations of thiourea in 0.1 M HCl on the Dowex50WX8 was also studied. The results clarified that the maximum uptake of tellurium was 98% on the Dowex50WX8, while the uptakes of 131I and thiourea are 1.96% and 70%, respectively. To purify 131I from thiourea (30%), which is not retained on Dowex50WX8, the remaining solution was shaken with different types of anion exchangers (Dowex21 K, Dowex1X8, and Dowex1X2) within 60 min. The most suitable anion exchanger, which gave the maximum uptake of 131I (80%) was Dowex21 K. Finally, 131I was re-extracted from Dowex21 K into 5 mM TBAB with a separation yield of 98%. Quality control on the separated product of tetra-butyl ammonium iodide (131I) was carried out.