Simultaneous Spectrophotometric Analysis of Fe2+ and Fe3+ Ions

Page: 200

M. Holbová and P. Lubal

Department of Analytical Chemistry, Faculty of Science, Masaryk University, Brno


Two new procedures for simultaneous spectrophotometric analysis of ferrous and ferric ions utilizing their different reactivities to a selective reagent (gallic acid) and/or reagent mixture (5-sulfosalicylic acid and 1,10-phenanthroline) were developed. The measured experimental data are treated by Artificial Neural Network. The concentration ranges used were 0.5-4.0 mg.l-1 (Fe2+) and 1.0-4.0 mg.l-1 (Fe3+) for the determination with gallic acid and 5.0-30.0 mg.l-1 (both ions) for the determination with the reagent mixture. It was demonstrated for the latter method that transition metal cations (Co2+, Ni2+, Mn2+, Cu2+, Zn2+) do not interfere and the method can be used for iron speciation analysis of Czech mineral waters. The proposed methods give precise (RSD < 2 %) and accurate results.


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