Extraction and Spectrophotometric Determination of Iron(III) with N1-Hydroxy-N1,N2-diphenylbenzamidine in Presence of Azide

Abstract

Abstract N 1-Hydroxy-N1,N2-diphenylbenzamidine (HDPBA) reacts with iron(III) in the presence of azide to give a violet-coloured complex insoluble in water. The mixed ligand complex having a composition of 1:2:2 (Fe:HDPBA:N3−) is quantitatively extracted into chloroform at pH 2–5. The violet-coloured complex has an absorption maximum at 530 nm with a molar absorptivity of 4900 l mol−1 cm−1. On the basis of this sensitive colour reaction, a highly selective method has been developed for the extraction and spectrophotometric determination of microgram quantities of iron(III). The effect of foreign ions and several experimental variables have been studied. The method is simple, rapid, precise, and free from the regid control of experimental parameters.