Polarography of Uranyl-Diethylenetriaminepentaacetate Complexes and Adsorption Kinetics at the Dropping Mercury Electrode

The chelation of uranium(VI) with diethylenetriaminepentaacetate was investigated polarographically over the p H range 3.7–8.4 and ligand concentration range 0.005–0.1M. The predominant chelate species was found to be with the logarithmic formation constant of 2.96 at p H 6.4–7.5 and ionic strength 0.25. In the presence of Triton , a single irreversible and diffusion‐controlled wave was obtained. The kinetic parameters were determined ( is the order of ). When the concentration of Triton X‐100 is greater than 0.003%, the single wave splits into two irreversible waves, due to the adsorption of surface active substance.