Abstract
Diethylenetriamine pentaacetic acid (DTPA) has been tested with 8 other new chelators for neptunium decorporation after systemic contamination in the rat. The ligands were injected intravenously at a dosage of 30 mumol.kg-1 and the animals killed 24 h later. The results show that none of the chelators tested was efficient in removing significant amounts of the radionuclide from the body. In order to understand why these chelators were ineffective, in vitro approaches have since been developed in which high concentrations of DTPA were added to Np-bearing ligands in the blood, liver and skeleton. The main conclusions were that under our experimental conditions neptunium was not chelatable after its organ deposition.