DETERMINATION OF VANADIUM BY ITS CATALYTIC EFFECT ON THE OXIDATION OF GALLOCYANINE WITH SPECTROPHOTOMETRIC FLOW INJECTION ANALYSIS

摘要

The use of a gallocyanine-bromate oxidation system for the direct determination of vanadium (0.020-100 ng/ml) with spectrophotometric detection is described. The decrease in absorbance results from the oxidation of gallocyanine by bromate in the presence of vanadium as a catalyst. The effects of important parameters, such as reagent concentration, reagent flow rates, sample volume, length of the reaction coil, and temperature, are reported. Vanadium can be determined al a rate of 40 +/- 5 samples/h. The limit of detection is 2 pg of V(V) for a 200 mu l of sample volume. The relative standard deviation for 10 replicated determinations of 1.00 ng/ml of V(V) is 1.1%. A new manifold is proposed for the elimination of potential interferences. The system was also applied for the determination of vanadium in serum, petroleum crude, and river water. (C) 1996 Academic Press, Inc. [References: 33]