Determination of the total iron by chitosan-modified glassy carbon electrode

A new preconcentration and voltammetric method was developed for the determination of total Fe by a chitosan modified glassy carbon electrode (CMGCE). The measurements were carried out by cathodic stripping voltammetry. Using the instability of Fe(C2O4)(3)(3-) to light and the reductive effect of C2O42-, the method can be used to determinate total iron. The effects of several experimental parameters, such as pH, the concentration of the modifier, deposition potential, deposition time, scan rate and UV absorption curves were studied for analytical applications. A linear response was obtained in the concentration range 2 x 10(-8)-3 x 10(-7) g/ml Fe with a detection limit of 1 x 10(-8) g/ml for a 2-min deposition time. A relative standard deviation (R.S.D.) of 3.67% was obtained for six determinations of 2x10(-7) g/ml Fe3+. The method can be used to determine the total iron in tap water and mineral water directly. (C) 2001 Elsevier Science B.V. All rights reserved.