流动注射分析光泽精-H_2O_2-Pb(Ⅱ)化学发光体系测定痕量铅的研究

Studies on the Determination of Trace Amount of Lead with Lucigenin-H_2O_2-Pb(Ⅱ) Chemiluminescence System by Flow Injection Analysis (FIA)

检测铅离子常用的方法有AAS法和双硫腙比色法,前者直接测定工业废水中的铅,灵敏度不高;后者操作步骤繁琐,须使用剧毒试剂氰化钾,污染环境,用流动注射化学发光法测定铅,仪器简单、操作简便、试样消耗量少、精密度高、分析快速准确、自动化程度高,因此,把流动注射分析和化学发光结合起来可以发挥两者的优点,利用光泽精(Lucigenin)-H_2O_2体系化学发光法测定铅,国内外报道甚少,我们发现,铅(Ⅱ)可催化H_2O_2氧化Lucigenin,通过条件实验,建立了流动注射化学发光测定痕量铅的方法,由于化学发光反应在强碱性介质中进行,大多数金属离子形成氢氧化物,采用巯基棉预先分离,本法灵敏度高,而且选择性好,应用于工业废水中痕量铅的测定,获得满意效果。

A new method is reported for the determination of trace amount of Pb(Ⅱ) with Lucigenin-H2O2-Pb(Ⅱ) chemiluminescence system by F1A. The detection limit of the method is 0. 5 μg/mL for Pb(Ⅱ). If the range of Pb(Ⅱ) concentration for the working curves was 0-100 μg/mL, the peak height was found to be linearly dependent on the concentration of Pb(Ⅱ). The relative standard deviation is less than 1.9%. The method was applied to determination of Pb(Ⅱ) in waste water with satisfactory results.