Voltammetry of hexacyanoferrates using a chemically modified carbon-paste electrode

Abstract

A simple electroanalytical method for the quantitative determination of hexacyanoferrate(II) and -(III) has been developed using a carbon-paste electrode, chemically modified with a weakly basic anion exchanger. The complexes can be pre-concentrated at the electrode surface prior to voltammetric determination. For differential-pulse voltammetric measurements with suitable methodical parameters, a linear relationship between the current and concentration was found for 0.3 to 6000 µg l^–1 of Fe. The method is applicable to the quantitative determination of hexacyanoferrate(II) in wine down to 6 µg l^–1 of Fe. Factors influencing the signal response like pre-concentration time and ionic effects have also been investigated.