Study of Ascorbic Acid as Iron(III) Reducing Agent for Spectrophotometric Iron Speciation

Abstract

The study of ascorbic acid as a reducing agent for iron(III) has been investigated in order\rto obtain an alternative carcinogenic reducing agent, hydroxylamine, used in\rspectrophotometric standard method based on the formation of a red-orange complex of\rFe(II)-o-phenanthroline. The study was optimised with regards to ascorbic acid\rconcentration as well as pH solution. The results showed that ascorbic acid showed\rmaximum capacity as reducing agent of iron(III) under concentration of 4.46.10-4 M and\rpH solution of 1-4.Under these conditions, ascorbic acid reduced iron(III) proportionally\rand performed similarly to that of hydroxylamine. The method gave result to linear\rcalibration over the range of 0.2-2 mg/L withhigh accuracy of 97 % and relative standard\rdeviation of less than 2 %. This method was successfully applied to assay iron speciation\rin water samples.