中性红催化荧光法测定钒(Ⅴ)

Determination of Trace Vanadium Using Neutral Red by Catalytic Fluorimetry

基于在磷酸介质中 ,钒对溴酸钾氧化中性红具有催化作用 ,使其荧光猝灭 ,建立了催化荧光法测定痕量钒的新方法 .研究了体系的动力学反应条件 ,采用固定时间法测定荧光猝灭程度 .方法的线性范围为0 .10～ 1.5 0 μg/L ,检出限为 0 .0 4 9μg/L .用于食物、水样中痕量钒 (Ⅴ )的测定 ,结果满意 .

A new kinetic fluorimetric method has been proposed for the determination of trace vanadium. The method is based on the catalytic oxidation of neutral red with potassium bromate in a phosphoric acid medium. The optimal kinetic conditions of experimentation have been studied. The optimal reaction temperature is 100 ℃ in boiling water. The optimal reaction time is 5 minutes. Flowing cold-water is chosen to stop the reaction. The linear range of the vanadium is 0.10～1.50 μg/L. The detection limit for vanadium is 0.049 μg/L. The proposed method suffers no interference from more than 20 foreign ions. The method had high sensitivity and high selectivity. This method has been applied to determine trace vanadium in flour and mineral water samples with satisfactory results.