Abstract

SPECTROPHOTOMETRIC DETERMINATION OF FE (II) AND FE (III) IN PRESENCE OF MICELLAR MEDIUM USING ORTHOHYDROXY BENZAMIDE IN PHARMACEUTICAL SAMPLES

Dr.D.Gopala Krishna* and .Ch.Kethani Devi

ABSTRACT

Two simple, sensitive, rapid and selective spectrophotometric methods have been developed for the determination of Fe (II) and Fe (III) by using newly synthesized reagent Ortho-Hydroxy Benzamide (SA) in presence of acidic surfactant C-TAB (5%). Fe (II) and Iron Fe (III) forms blue coluored water-soluble complex with SA at pH 5.0 and 5.5 and the complexes shows the maximum absorbance at max 400 and 420 nm for Fe (II) and Fe (III) respectively. At these wavelengths (max), the complex shows maximum absorbance while the reagent blanks shows negligible absorbance. Beer's law was obeyed in the range 0.139-1.396 μg/ml and the optimum concentration range from ringbom plot was 0.279-1.256 g/ml for Fe (II) and Fe (III) respectively. The molar absorptivity and Sandell's sensitivity for the coloured solution were found to be 3.88x104 L mol-1cm-1 and 0.0018-μg.cm-2 for Fe (II) and 4.81x104 L mol-1 cm-1 and 0.00116-μg.cm-2 for Fe (III) respectively. The interference effects of various diverse ions have been studied. Fe (II) and Fe (III) forms 1:1 complex with SA stoichiometry with stability constant 3.4x105 for Fe (II) and 3.5x105 for Fe (III). The standard deviation in the determination of 0.558-μg ml-1 of Fe (II) and Fe (III) was found to be 0.0013 and 0.01 respectively. First and second order derivative Spectrophotometric methods was developed at max 420, 440 nm for Fe (II) and at 440, 470 nm for Fe (III) which is more sensitive than the zero order method. The developed method has been employed for the determination of Fe (II) and Fe (III) in Synthetic Alloy samples. The results are in good agreement with the certified values.

Keywords: Fe (II) & (III), Spectrophotometry, Synthetic Alloy samples, Micellar medium, CTAB (5%), SA.