复合汞膜阳极溶出法检测树叶上的附着铅

Detection of Adhered Lead Content on Leaves by Anodic Stripping Voltammetry with Composite Mercury Film

[目的]快速、简便测定树叶上的附着铅含量。[方法]以新型铕离子掺杂普鲁士蓝复合汞膜电极为工作电极，采用差示脉冲阳极溶出法，测定兰州市3个地点的城区绿化白蜡树叶上附着铅含量，并分析树叶上附着铅的主要污染来源。[结果]在介质0．01mol／LHNO3富集电位-1．000V、富集时间60s条件下，Pb^2＋的溶出峰电流与其浓度在2．4～120．0μg/L范围内存在良好的线性关系，检出限为0．2μg/L，RSD为1．35％。树叶上附着铅含量与邻近交通要道的车流量之间有一定的正相关性，表明汽车尾气是兰州市绿化白蜡树叶上附着铅的重要来源。[结论]复合汞膜阳极溶出法检测树叶上附着铅含量具有较高的准确度和较好的精密度，而且操作简便、快速，测定干扰小。

[ Objective] The aim was to determine the adhered lead content on leaves rapidly and easily. [ Method] With new type europium ion and adulterated with composite mercury film electrode of prussian blue as working electrode, the lead content on leaves of Chinese ash for greening in urban area in 3 places of Lanzhou city was determined by using differential pulse anodic stripping voltammetry, and the major pollution source of adhered lead on leaves was analyzed. [ Result] Under the conditions of medium 0.01 mol/L HNO3, enrichment potential - 1.0 V and enrichment time 60 s, the stripping peak current of Pb^2＋ had good linear relation with its concn, within 2.4 - 120.0 μg/L, the detection limit was 0.2 μg/L and RSD was 1.35%. The leaves＇ adhered lead content had a certain positive correlation with the vehicle flow that near to vital traffic lines, which indicated that the automobile tail-gas was the important source for the adhered lead on leaves of Chinese ash for greening in Lanzhou. [ Conclusion] The anodic stripping voltammetry with composite mercury film had a higher and better accuracy and precision in detecting the adhered lead content on leaves, and the operation was simple, convenient and fast with little disturbance in determination.