The determination of the stability constants of uranyl and thorium with aminopolycarboxylic acids

The stability of uranyl and thorium ions with ligands N-(2′-carboxy phenyl) iminodiacetic acid (ADA), iminodiacetic acid (IDA) and (ethylenedioxy)diethylenedinitrilo]tetraacetic acid (EGRA) have been studied using the potentiometric technique in 0.1M, KNO₃ solution at 25°C. The complexes of thorium (IV) ions with IDA and ADA are shown to be more stable than those for uranyl ions, while EGTA forms more stable complexes with uranyl ion.