KINETIC THERMOMETRIC DETERMINATION OF VANADIUM IN ATMOSPHERIC AEROSOLS BASED ON ITS CATALYTIC EFFECT ON THE OXIDATION OF TANNIC-ACID BY BROMATE ION

The catalytic effect of vanadium(V) on the oxidation of tannic acid by bromate ion was studied in order to develop a simple method for determination of vanadium(V). By using the initial rate method and monitoring the reaction thermometrically, vanadium can be determined at the typical levels found in atmospheric aerosols (5-50 ppb) with a relative standard deviation of 6.3%. The sensitivity of the determination is enhanced by the presence of citric or tartaric acid. The proposed method is subject to interference only by iron in concentrations over 75 times that of vanadium, which is rarely the case with atmospheric aerosols. The results obtained are compared with those provided by the two most frequently used techniques for vanadium determination in atmospheric aerosols, viz. ICP-AES and graphite furnace AAS.