Adsorption of ⁹⁰Sr on SuperLig®620 Solid Phase Extraction Beads

For setting a procedure of separating ⁹⁰Sr in aqueous using SuperLig®620, the performance of SuperLig®620 solid phase extraction beads for the adsorption of strontium in aqueous solution was studied. The influences of contact time, nitric acid concentration, strontium carrier and ammonium citrate concentration on distribution coefficient K_d were studied. The K_d is more than 1 000 mL/g when contact time is longer than 30 min in 0.1 mol/L HNO₃. The resin can not adsorb any other radionuclides except ¹³³Ba when c(H⁺)＞1 mmol/L. ⁹⁰Sr and ¹³³Ba can be eluted respectively using different concentrations of ammonium citrate. Based on the results, a separation procedure of ⁹⁰Sr in environmental water samples using SuperLig®620 solid phase extraction beads was presented. The optimal separation was found using a 0.1 mol/L HNO₃ load solution with a 10V_c 0.1 mol/L HNO₃ to wash potential interferences. Then ⁹⁰Sr was eluted using 9V_c 0.1 mol/L ammonium citrate. The yield of strontium is more than 99%, and the decontamination factor is more than 3×10³.