Comparative investigation of some Tc-99m radiopharmaceuticals in the gel chromatography analysis

摘要

The radiochemical purity of three bone seeking complexes labelled with ~(99m)Tc was determined by means of gel chromatography on Sephadex G 25 M. The components examined were ~(99m)Tc(Sn)-pyrophosphate(~(99m)Tc(Sn)-Pyp), ~(99m)Tc(Sn)-melhylene diphosphonate (~(99m)Tc(Sn)-MDP) and ~(99m)Tc(Sn)-2,3 dicarboxy propane diphosphonate (~(99m)Tc(Sn-DPD). The effect of the composition and pH of the eluent on the separation of the three radiochemical components in the obtained radiopharmaceuticals was determined. It was found that the results of the analyses directly depend only on the composition of the eluent. The yield of the c helate fraction was lower if pure saline solution (0.154 mol/dm~3 NaCl) was used as the eluent. The best results were obtained when both the ligand and the reductant were contained in the saline solution. The concentrations of the reagents should correspond to those applied in the preparation of the complex. Under this condition the dissociation of the complexes due to the dilution is avoided and Sephadex can be used in the gel chromatography of the examined radiopharmaceuticals.