99mTc-1,7-bis (2-pyridyl)-2,6-diazaheptane (DPTN) complexes: Production yield and stability in slightly basic media

Abstract

The reduction of99mTc by SnCl2 in the presence of 1,7-bis (2-pyridyl)-2,6-diazaheptane (DPTN) has been investigated in borate buffer solutions with pHs ranging from 6.7 to 9.5. The resulting cationic, neutral and anionic complexes, in addition to TcO2 and TcO 4 − impurities, were separated by high voltage paper electrophoresis. The cationic complex turned into neutral and then into an anionic form via hydrolysis. These three species were also separated by gel filtration on a Bio-Gel P-2 column; their formation yields, stability, and the rate of their hydrolysis are presented as a function of the pH, and the results are discussed.