研究了用4-(2-吡啶偶氮)-间苯二酚(PAR)为沉淀剂, 以Fe(Ⅲ)为载体离子的共沉淀体系快速共沉淀分离富集水样和奶茶粉中的铅, 并用火焰原子吸收光谱(FAAS)方法测定。 共沉淀过程受体系酸度、 载体铁、 沉淀剂PAR的用量及陈化时间的影响。 结果显示, 在pH为6.0的条件下, 能够定量共沉淀试样中的铅。 方法检出限为18.7 μg·L-1, 用于水样及奶茶粉的加标回收率为94.2%～98.3%, 相对标准偏差为1.03%～2.24%, 排除了基体干扰, 结果较为满意。 本法与传统的共沉淀方法比较, 具有快速、 简便、 重现性好的优点。

A method was proposed for the determination of trace lead with flame atomic absorption spectrometry after preconcentration of lead by rapid coprecipitation technique with PAR-Fe(Ⅲ) at pH 6.0. The analytical parameters including pH, amount of iron(Ⅲ), amount of reagent, the standing time of the precipitate, etc., were examined. The detection limits (DL) were found to be 18.7 μg·L-1 for Pb(Ⅱ). In analysis of lake water and the milk tea powder samples, RSD’s and the standard addition recovery of this method were in the ranges of 1.03%～2.24% and 94.2%～98.3% respectively. The effect of matrix can be overcome by the method and the results are satisfyiog. The method shows good application prospect in the determination of trace lead owing to its rapidness and reproducibility.