Kinetic-Catalytic Determination of Vanadium(IV) Using Methyl Orange-Bromate Redox Reaction

Abstract

Determination of V(IV) based on its catalytic effect on the reaction between Methyl Orange and bromate in the presence of citric acid was studied. The calibration curve obtained by fixed-time method was linear in the range of 2.5-300 ng ml^-1. By use of slope method, a calibration curve containing two linear portions were obtained. Using fixed-time and slope methods, we obtained detection limits of 0.8 and 1.5 ng ml^-1, respectively. Fe²⁺, As(III), V(V) and Hg²⁺ interfered. The method was successful for analysis of water samples.