Kinetic determination of traces of Al(III) ion by its catalytic effect on oxidation of 4-hydroxycoumarin by potassium permanganate

Abstract

Oxidation of 4-hydroxycoumarin by potassium permanganate in acid media of acetate buffer is catalyzed by Al(III) ions, which is the basis of the proposed new homogenocaralytic

method for determinati on of Al(III) in solutions. Under the optimum conditions, Al(III) has been determined at 525 nm in solutions containing analyte at 50-1000 ng/ml with probable relative error of 15.6-5.1 % and detect ion limit of 20 ng/ml. Appropriate kinetic equations for both catalytic and noncatalytic processes have been derived and the mechanism of catalytic effect of Al(III) investigated. Interference studies show that most of the common cat ions and anions do not interfere.