Efficient phase transfer of pertechnetate with bicyclic guanidinium compounds

Extraction of pertechnetate with bicyclic guanidinium compounds has been studied in the system KTcO₄-buffer-H₂O/ligand-trichloromethane. Extraction data of guanidinium ligands have been compared with trialkylmethylammonium (Aliquat 336), tetraphenylphosphonium and tetraphenylarsonium chloride. The lipophilicity of extractants investigated was determined by RP-HPLC. The efficiency of pertechnetate extraction correlates with the lipophilicity of the guanidinium compounds. 1:1 complex formation in the organic phase was observed. The influence of hydroxide, chloride and bicarbonate on the pertechnetate extraction has been investigated. Pertechnetate is extracted with great preference over OH^-, Cl^- and HCO₃ ^-.