Chromatographic study of¹⁸⁶Re complexes with various ligands

Abstract

Thin-layer and paper chromatography have been used for the determination of radiochemical yields of¹⁸⁶Re complexation with three selected ligands methylenediphosphonic acid (MDP), ethylenediamminotetraacetic acid (EDTA), and citrate convenient for the radiopharmaceutical applications. The combination of selected two chromatographic systems has been chosen due to the satisfactory separation of free perrhenate, corresponding complex with¹⁸⁶Re and reduced hydrolyzed rhenium. Rhenium complexes with studied ligands were prepared by reduction of perrhenate at presence of suitable ligand. Stannous chloride together with ascorbic acid (antioxidant) was used for perrhenate reduction. The effect of pH of reaction mixture, reaction time and concentration of reducing agent on the radiochemical yield of complexation is described and the optimal conditions for synthesis of rhenium complexes with MDP, EDTA and citrate have been found. Under optimal condition the radiochemical yield of complexation¹⁸⁶Re-MDP,¹⁸⁶Re-EDTA and¹⁸⁶Re-citrate reached more than 90%, 80%, and 80%, respectively.