Abstract

Spectrophotometric determination of iron as iron(III) in water samples of certain lakes situated around Tumkur through oxidative nucleophilic coupling reaction between catechol and nitroaniline

Author(s): C.Vijaya Bhaskar, Mansour S.Abdul Galil, M.A.Satish, B.Shyla, Mahadevaiah, G.Nagendrappa

A simple, rapid and a sensitive spectrophotometric method is developed here for the determination of iron(III) through iron(III) mediated nucleophilic coupling reaction between catechol and p-nitroaniline, system 1 or catechol and m-nitroaniline, system 2. The method is based on catechol oxidation by iron(III) followed by its nucleophilic coupling with m-nitro aniline or p-nitro aniline in 0.1Mhydrochloric acid medium forming a dye with max540 nmobeyingBeerÂ’s law in the range, 0.8-20 gml-1 for both the systems. Themolar absorptivity values for system1and system2 were found to be 9.379X102 lmol-1cm-1and 8.8032X102 lmol-1cm-1 respectivelywith the corresponding SandellÂ’s sensitivity values, 0.0595µg cm-2 and 0.0634 µg cm-2. The composition of the dye product was determined and found to be 1:2 for both systems The systems were used for the determination of iron in water samples of certain lakes situated around Tumkur. The results obtained by both the systems were reproducible and comparable with the results of iron determined separately by phenanthroline method.