Croatica Chemica Acta, Vol. 78 No. 1, 2005.
Original scientific paper
Determination of Stability Constants of Metal-methylcysteine and Metal-methylcysteine-cysteine Complexes by Paper Ionophoretic Technique
Brij B. Tewari
Abstract
A method, involving the use of an advanced paper ionophoretic technique is described for the study of equilibria in mixed complex systems in solution. The method is based on the migration of a spot of metal ion, with the complexants added in the background electrolyte. The concentration of one of the complexants, methylcysteine, is kept constant while that of the second ligand, cysteine, is varied. A graph of log [cysteine] against mobility is used to obtain information on the mixed-ligand complexes and to calculate their stability constants. Stability constants of metal-methylcysteine-cysteine complexes were found to be 3.05 ± 0.13 and 4.31 ± 0.11 (logarithm of stability constant values) for aluminium(III) and thorium(IV) respectively, at ionic strength of 0.1 mol dm–3 and a temperature of 35 °C
Keywords
paper ionophoretic technique; aluminium(III) complexes; thorium(IV) complexes; mixed ligand metal complexes; methylcysteine; cysteine; overall mobility; stability constants
Hrčak ID:
2665
URI
Publication date:
24.3.2005.
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