V(V)ASApA-KBrO_3催化动力学光度法研究及应用

Study on Catalytic Kinetic Spectrophotometric System of V(V)-ASApA-KBrO_3and Its Application

研究了pH值在1.0～1.5磷酸介质中,柠檬酸存在下,痕量钒对溴酸钾氧化对乙酰基偶氮胂的褪色反应及其动力学条件,建立了测定痕量钒的新方法。本法表观摩尔吸光系数ε_(max)=2.64×10~6 L·mol^(-1)·cm^(-1),线性范围为0～10ng·ml^(-1),检出限为1.41×10^(-11)g·L^(-1)。方法用于测定自来水、湖水、芹菜样中痕量钒(V),取得了令人满意的结果。

A new method was developed for the determination of trace vanadium in which vanadium (V) catalyzes the decoloring reaction of p-acetylarsenazo with potassium bromate in phosphoric acid medium in the presence of citric acid. The apparent molar absorptivity of the method is epsilon = 2.64 x 10(6) L(.)mol(-1 .) cm(-1) at 532 nm. The linear range of the determination of vanadium is 0similar to10 ng(.)ml(-1). The detection limit of the method for vanadium is 1.41 x 10(-11) g(.)L(-1). The method has been used in the determination of trace vanadium in tap water, lake water and celery samples with satisfactory results. The possible kinetic mechanism of the reaction was proposed.