氢化物发生-原子荧光光谱法测定痕量铅的改进研究

Improvements of determination of trace lead by hydride generation atomic fluorescence spectroscopy

目的：对氢化物发生-原子荧光光谱法测定痕量铅的分析条件进行试验并予以优化。方法：用酸洗活性炭处理铁氰化钾,对铁氰化钾抑制常见几种共存元素干扰能力进行了测试,在不同盐酸介质浓度及硼氢化钾浓度条件下对样品进行测定。结果：酸洗活性炭处理铁氰化钾后能降低空白荧光值,并具有一定的抑制共存元素干扰作用;在选定最佳工作条件下,方法的线性范围为0～50μg/L,检出限为0.14μg/L,相对标准偏差（对10.0μg/L Pb,n=20）为1.5%。应用该法对大米和水样中铅含量进行了测定,加标回收率为93.0%～104.8%。结论：分析条件优化后,该方法适用于公卫样品痕量铅的测定。

Objective：To optimize the conditions for determination of trace lead by hydride generation atomic fluorescence spectroscopy.Methods：Potassium ferricyanide should be treated with acid-washed activated carbon and its efficiency on interference of coexisting ions was tested.The sample was determined at different concentrations of hydrochloric acid and potassium ferricyanide.Results：The fluorescence signal of blank solution was decreased evidently by treating potassium ferricyanide with acid-washed activated carbon.The interference of coexisting ions could be suppressed in some degrees in the presence of potassium ferricyanide.Under the optimum conditions,linear relationship was kept in the rage of 0 to 50 μg/L and the detection limit of this method was 0.14 μg/L.The relative standard deviation（RSD） of the procedure was 1.5%（10.0 μg/L Pb,n=20）.The present procedure was applied for determination of lead in rice and water,and the recoveries from samples varied from 93.0% to 104.8%.Conclusion：After optimizing conditions,this method can be applied to the determination of trace lead in hygienic samples.