DETERMINATION OF MIXED STABILITY CONSTANTS OF LEAD(II)/URANYL(II)-NTA-CYSTEINE COMPLEXES BY PAPER ELECTROPHORESIS

Abstract

A method involving the use of paper ionophoresis is described for the study of equilibria in mixed – ligand complex systems in solution. The technique is based on the movement of a spot of metal ion under an electric field with the complexants added to the background electrolyte at pH 8.5. The stability constants of the complexes Pb(II) – nitrilotriacetate – cysteine and UO₂(II) – nitrilotriacetate – cysteine are found to be 5.35 ± 0.02 and 6.27 ± 0.07 (logarithm of stability constant values) at ionic strength 0.1 M and a temperature of 35 0C.



KEY WORDS: Paper ionophoresis, Lead(II) complexes, Uranyl(II) complexes, Nitrilotriacetic acid, Cysteine, Stability constants.


Bull. Chem. Soc. Ethiop. 2005, 19(2), 257-265.