Micellar catalysis in kinetic multicomponent analysis: simultaneous determination of binary mixtures of cyanide, sulfide, and sulfite ions

Abstract

A simultaneous kinetic resolution of binary mixtures of cyanide, sulfide, and sulfite by reaction with 5,5'-dithiobis(2-nitrobenzoic acid) (DTNB) in aqueous cetyltrimethylammonium bromide (CTAB) micelles was developed. The use of micelles increased the rate constants of the three reactions involved to a different extent and this differential behavior permitted the simultaneous kinetic analysis of mixtures of the anions by using appropriate surfactant concentrations. The determination of binary mixtures of cyanide, sulfide, and sulfite over the concentration ranges (0.6-1.5) ×10 -4 , (0.2-1)×10 -4 , and (0.2-1.5)×10 -4 M, respectively, was accomplished with relative errors less than 5%