Iminodiacetate complexes of technetium: an electrochemical study

Iminodiacetate complexes of technetium are used extensively in diagnostic medical imaging, but their chemical structure and properties are yet uncertain. We studied formation of technetium-99 complexes with diethylenetetraminepentaacetate (DPTA), ethylenediaminetetraacetate (EDTA), N-(2-acetamido)iminodiacetate (ADA), and N-(2,6-dimethylphenylcarbomoylmethyl)iminodiacetate (HIDA) by tast (sampled DC) polarography, reverse-pulse polarography, controlled-potential coulometry, and amperometric titration. The products, often mixtures, varied with reaction conditions and ligand; this can explain apparent contradictions in previous studies.