Trace Amounts Determination of Vanadium (V) Using a New Kinetic-Catalytic Reaction System

This study describes a new simple, sensitive and selective catalytic kinetic spectrophotometric method for the determination of vanadium (V). The method is based upon the catalytic effect of vanadium (V) on the oxidation of Carminic acid by bromate in sulfuric acid media. The reaction was followed spectrophotometrically by measuring the decrease in absorbance at 490 nm and the dependence of sensitivity on the effective reaction variables was studied. Under optimum experimental conditions, the fixed time procedure was used to obtain a calibration curve over the range of 0.05–10.8 μg mL-1of vanadium (V). The calculated detection limit was 0.015 μg mL-1 for twelve replicate measurement of blank signal. The relative standard deviations (n = 6) were 1.12, 0.98% for 2.0, 8.0 μg mL-1 of vanadium (V), respectively. The effect of various species commonly associated with vanadium (V) in real samples was also investigated. The proposed method was successfully applied for the determination of vanadium (V) in water and standard alloy samples.