Catalytic Kinetic Spectrophotometric Determination of trace Vanadium with naphthol green B as indicator

A new kinetic spectrophotometric method has been developed for the determination of trace vanadium.It is based on the catalytic effect of V(V)on the redox reaction between naphthol green B(NGB)and potassium bromate in phosphoric acid in the presence of ammouium sulfate.The linear range of determination is 02～22 μg/L.The method has been used for the determination of little vanadium in hair and water with satistactory result.