抑制荧光光谱法测定模拟废水中痕量汞

基于在pH 8.00磷酸氢二钠-柠檬酸缓冲介质中,血红蛋白对过氧化氢氧化对甲酚反应具有强的催化作用,汞(Ⅱ)对上述指示反应具有灵敏的抑制作用,从而提出了抑制荧光光谱法测定模拟废水中汞含量的方法。优化的试验条件如下:①血红蛋白的浓度为2.00×10-7 mol·L-1;②对甲酚的浓度为1.60×10-3 mol·L-1;③过氧化氢的浓度为1.11×10-3 mol·L-1;④反应时间为80min。在激发波长318nm、发射波长405nm处,反应体系的ΔF(即F0与F值之差)与汞(Ⅱ)的浓度在2.00×10-8～1.00×10-5 mol·L-1范围内呈线性关系。方法用于模拟废水的分析,测得加标回收率在94.0%～105%之间,相对标准偏差(n=8)在2.5%～3.3%之间。

Inhibitory Fluorophotometric Determination of Trace Amount of Mercury in Simulated Wastewater

It was found that in Na2HPO4-citric acid buffer medium of pH 8.00,the oxidation of p-cresol by hydrogen peroxide was strongly catalyzed by haemoglobin(Hb),leading to an enhancement of fluorescence.The indicator reaction was inhibited by the presence of Hg(Ⅱ).Based on these facts,the determination of trace amount of Hg(Ⅱ) in simulated wastewater by inhibitory spectrofluorimetry was proposed.The optimized conditions found were as follows: ① concentration of Hb: 2.00×10-7mol·L-1;② concentration of p-cresol: 1.60×10-3mol·L-1;③ concentration of H2O2: 1.11×10-3mol·L-1;④ time of reaction: 80 min.Linear relationship was found between values of ΔF(F0-F) determined at wavelengths of 318 nm(λex) and 405 nm(λem) and concentration of Hg(Ⅱ) in the range of 2.00×10-8-1.00×10-5mol·L-1.The proposed method was used in the analysis of simulated wastewater,giving values of recovery and RSD′s(n=8) in the ranges of 94.0%-105% and 2.5%-3.3%.