Electrophoretic studies on the mixed nitrilotriacetate-penicillamine complexes of Pb2+ and UO 2 2+

A technique involving the use of paper electrophoresis is described for the study of binary and mixed-complex systems in solution. This technique is based on the movement of a spot of metal ion in an electric field with the complexants added in the background electrolyte at pH 8.5. The concentration of primary ligand (nitrilotriacetate) was kept constant, while that secondary ligand (penicillamine) was varied. A graph of logpenicillamine] versus mobility was used to obtain information on the mixed complexes and to calculate stability constants. The stability constants of mixed-ligand complexes lead(II)-nitrilotriacetate-penicillamine and uranyl(II)-nitrilotriacetate-penicillamine have been found to be 5.68 ± 0.09 and 6.56 ± 0.05 (logarithm stability constant values), respectively, at ionic strength 0.1 M and a temperature of 35°C. The text was submitted by the author in English.