KINETIC ENTHALPIMETRIC DETERMINATION OF VANADIUM(V) BY ITS CATALYTIC EFFECT ON THE OXIDATION RATE OF PYROGALLOL RED BY POTASSIUM BROMATE

The V(v)-catalysed oxidation of Pyrogallol Red by BrO3- was monitored enthalpimetrically. The rate of the reaction was determined graphically from the initial linear slope of the temperature-time curve recorded and was found to be proportional to the V(v) concentration over the range 10-150 ng ml-1. The relative standard deviation obtained for the determination of a 100 ng ml-1 concentration of the analyte was 6%. Foreign species did not interfere at concentrations as high as 20-mu-g ml-1. The method was applied to the determination of V(v) in steel with good results.