Abstracto

Spectrophotometric determination of benzidine present in pure sample and in industrial effluents

M.A.Sathish, M.S.Yogendra Kumar,Mansour S.Abdul Galil, Mahadevaiah, B.Shyla, C.Vijaya Bhaskar, G.Nagendrappa

Two simple, rapid, economical and highly sensitive spectrophotometric methods have been developed for the determination of benzidine(BZ) present in its pure samples and in industrial effluents. The methods are based on oxidation of benzidine either with cerium(IV)sulfate in sulfuric acid medium(method A) or with electrolytically generated manganese (III)(methodB).The colored ion-pairs formed aremeasured at 430 and 410nm for methodsAand B respectively. Beer’s law is obeyed in the concentration range of 0.10-0.71(methodA) and 0-4gml-1(method B).The respectivemolar absorptivities are 6.27104 and 3.52104lmol-1cm-1with the corresponding Sandell sensitivities values 0.0029 and 0.005g/cm2.The stability constants values of the complexes as determined bymodified Job’s method are 2.11105 and 4.23 104 l mol-1 respectively for methodsAand B. The new methods have been applied successfully for the analysis of benzidine in pure form or in industrial effluents with good accuracy and precision. The results from the developed methods are in good agreement with the reported method. The mechanism of benzidine oxidation either with cerium(IV)sulfate or manganese(III) is also proposed. The stoichiometry between benzidine and cerium(IV)sulfate or manganese(III) is 1:2 for both the methods.