ADSORPTIVE STRIPPING VOLTAMMETRIC STUDY OF SCANDIUM–ALIZARIN COMPLEXAN COMPLEX AT A CARBON PASTE ELECTRODE

ABSTRACT

A highly selective, sensitive, rapid and economic adsorptive stripping voltammetric method has been developed for the determination of ultra trace amount of scandium at a carbon paste electrode (CPE) in the current paper. The Sc(III)−alizarin complexan (ALC) complex is adsorbed at the electrode in a mixed buffer solution (pH 5.4) containing 0.04 M acetate and 0.016 M biphthalate, yielding one peak corresponding to the reduction of ALC in the complex at −0.60 V (vs. SCE). The second-order derivative linear scan voltammograms of the complex are recorded by use of model JP−303 polarographic analyzer from −0.10 to −1.10 V. A linear relationship between the second order derivative peak current and Sc(III) concentration in the range of 1.0 × 10⁻⁹ to 6.0 × 10⁻⁷ M is observed. The detection limit for Sc(III) is 6.0 × 10⁻¹⁰ M. A relative standard deviation of 4.34% is given for ten determinations of 6.0 × 10⁻⁸ M Sc(III). The method has been applied to the determination of the trace Sc(III) in the mineral samples with satisfactory results.

Keywords:

• Scandium
• Alizarin complexan
• Adsorptive stripping voltammetry
• Carbon paste electrode

ACKNOWLEDGMENTS

This research work was supported by a grant from the Scientific Research Funds of Hunan Provincial Education Department of China (01C113) and State Key Laboratory of Electroanalytical Chemistry of Changchun Institute of Applied Chemistry, Chinese Academy of Sciences.