CATALYTIC SPECTROPHOTOMETRIC DETERMINATION OF VANADIUM (IV) BASED ON THE OXIDATION OF ALKALI BLUE BY POTASSIUM BROMATE

Document Type: Regular Paper

Authors

Department of Chemistry, College of Science, Shiraz University, Shiraz 71454, I. R. of Iran

Abstract

A simple, rapid and sensitive spectrophotometric method has been proposed for the determination
of Vanadium (IV). The method is based on the catalytic effect of V (IV) on the oxidation of Alkali Blue by
potassium bromate at pH 4. The rate of decrease in the absorbance of Alkali Blue (at 572 nm) was
proportional to the concentration of V (IV) in the range of 100-6000 ng ml-1. The detection limit was 40 ng
ml-1. The proposed method shows a good selectivity for V (IV) over a wide variety of interference species. It
is also valuable in that the presence of a 400 fold excess of V (V) can be tolerable, contrary to many methods
for the determination of V (IV) which suffer from severe interference of V (V). This method was successfully
applied to the determination of V (IV) in river water, alloy samples and several synthetic samples.

Keywords