Determination of radiochemical yield of 186Re-labeled complexes using thin-layer chromatography

The reaction conditions for synthesis of three rhenium complexes Re-186-methylendiphosphonate (MDP), Re-186-hydroxyethylidendiphosphonate (HEDP) and Re-186-citrate were investigated. Radiochemical yield of complexation was determined by thin-layer chromatography and paper chromatography. The rhenium complexation with corresponding ligand was dependent on pH values of reaction mixture, concentration of the ligand studied (MDP, HEDP and sodium citrate) and concentration of the reducing agent. Stannous chloride with ascorbic acid las antioxidant) was used for reduction of perrhenate. The labeling yield was about 90% for Re-186-MDP, more than 80% for Re-186-HEDP and more than 75% for Re-186-citrate under optimum conditions. The possibility of application of porphyrines as organic ligands for complexation with rhenium isotopes was also examined.