溴酸钾二甲酚橙体系-顺序注射-催化光度法测定痕量钒

在酸性介质条件下,钒(Ⅳ)能显著催化溴酸钾对二甲酚橙的氧化褪色反应。据此建立了测定痕量钒(Ⅳ)的顺序注射催化光度法。方法的线性范围为0.5⁵0ng/mL、检出限为0.4ng/mL。对10ng/mL的钒(Ⅳ)连续11次测定的相对标准偏差为1.1%。用于环境水样中痕量钒(Ⅳ)的测定,加标回收率为91%50ng/mL、检出限为0.4ng/mL。对10ng/mL的钒(Ⅳ)连续11次测定的相对标准偏差为1.1%。用于环境水样中痕量钒(Ⅳ)的测定,加标回收率为91%¹08%。

Determination of Trace Vanadium in Environmental Water Samples by Xylenol Orange-Potassium Bromate System -Sequential Injection-Catalytic Spectrophotometry

In acidic medium, potassium bromate could oxidize and decolorize the xylenol orange under the catalysis of micro V(IV). A new catalytic spectrophotometric method combined with sequential injection has been used for the determination of trace V(IV) based on this oxidation reaction. Under the optimized experimental conditions, the linear ranges were 0.5~50 ng/mL with the detection limit of 0.4 ng/mL. The relative standard deviation for eleven replicate determinations of the certified reference materials containing 10 ng/mL V(IV) was 1.1%. The method has been used in the determination of trace vanadium in environmental water samples with recovery over 91%~108%.