Determination of vanadium in groundwater samples with an improved kinetic spectrophotometric method.
A kinetic catalytic method has been developed for the determination of vanadium based on its catalytic effect on the redox reaction of azorubin S and bromate in the presence of a sulphuric and nitric acid mixture. The reaction is monitored spectrophotometrically by measuring the decrease in absorbance of the reaction mixture at 515 nm. The fixed-time method was used for 0.5-5 min. Optimization of the reaction conditions regarding concentrations of acids, dye, oxidant, masking agent, etc. was investigated. The rate of decrease in absorbance of azorubin S was proportional to the concentration of vanadium in the range of 2.0-1.05 x 10(3) ng mL(-1). 3Sb/m was 0.0129 ng mL(-1) and 10 Sb/m was 0.0432 ng mL(-1). The catalytic method based on the oxidation reaction of azorubin S and bromate shows a good selectivity for vanadium over a wide variety of interference cations and anions. The proposed method was successfully applied to the determination of vanadium in groundwater samples and spiked-water samples.
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Bağda
D001959:Bromates / Q000737:chemistry; D004492:Edetic Acid / Q000737:chemistry; D060587:Groundwater / Q000032:analysis*; D009282:Naphthalenesulfonates / Q000737:chemistry; D017942:Nitric Acid / Q000737:chemistry; D013053:Spectrophotometry / Q000379:methods*; D013464:Sulfuric Acids / Q000737:chemistry; D014639:Vanadium / Q000032:analysis* / Q000737:chemistry
D001959:Bromates; D009282:Naphthalenesulfonates; D013464:Sulfuric Acids; D014639:Vanadium; D017942:Nitric Acid; D004492:Edetic Acid; C006671:azo rubin S; C033158:sulfuric acid