Development of Extractive Spectrophotometric Methods for the Determination of Iron(III) with Dimercaptophenole and Heterocyclic Diamines

Abstract

Dimercaptophenole (DM) is proposed as a new sensitive reagent for the sensitive extractive spectrophotometric determination of Fe(II). DM in the presence hydrophobic amins reacts with Fe(II) in the pH range 5.3 -7.2 to form a coloured complex. Chloroform, dichloroethane, and carbon tetrachloride appeared to be the best extractants. The absorption spectrum of Fe (II)-DM-Am complexes in chloroform shows maximum absorbance at 552-583 nm. It was observed that the color development was instantaneous and stable. Linear calibration graphs were obtained for 0.03-4.2 μg mL −1 of Fe.The molar absorptivity calculated was found to be (3.08-4.33) and#215; 104 dm3 mol−1 cm−1 and the sensitivity of the method as defined by sandaland#39;s was 1.29-1.82 ng cm-2. The stoichiometry of the complex is established as 1:1:2 (M : L : Am) by equilibrium shift method, and confirmed the methods of relative yield, Asmus straight line and the intersection curves. It may be satisfactorily applied for the determination of Fe(III) with present method. The results of the prescribed procedure applied for the determination of the micro amounts of iron in pharmaceutical, biological, water, food and in plant samples are presented.