Fractional Determination of Nanogram Amounts of Vanadium(IV) and Vanadium(V) in Natural Water by a Catalytic Method Combined with Solvent Extraction

Abstract

A simple and sensitive method has been developed for the fractional determination of nanogram amounts of vanadium(IV) and vanadium(V) in natural waters. It is based on the solvent extraction of these ions with N- cinnamoyl-N-(2, 3-xylyl)hydroxylamine into toluene at different pH values, followed by back-extraction into a sodium hydroxide solution and on the determination of vanadium by a catalytic method using the oxidative coupling reaction of 4-aminoantipyrine with N, N-dimethylaniline. Vanadium(IV) and vanadium(V) at the 0.1-1.0ng ml^-1 level can be determined. The proposed method suffers few interferences and can be successfully applied to the fractional determination of vanadium in natural water.