研究了Pb(Ⅱ)-双硫腙(H2D2)-PAR三元配合物的显色体系,该体系的最大优点是可在水相中直接用光度法测定样品中铅。Pb(Ⅱ)、双硫腙和PAR形成1:1:1橙红色配合物,最大吸收波长为530 nm,表观摩尔吸光系数ε=2.25×104L·mol-1·cm-1,Ph(Ⅱ)在0-3.0μg·ml-1范围内符合朗伯-比耳定律。以邻二氮菲、NH4SCN、酒石酸钾钠做联合掩蔽剂,可消除常见金属离子的干扰。此方法显色迅速、稳定、操作简便,避免了使用氰化钾剧毒试剂及萃取等繁琐操作。已用于测定自来水、雪水以及人发中铅的含量,结果满意。 The colorimetric system of Pb (Ⅱ) -dithihydrazone (H2D2) -PAR ternary complex has been studied. The biggest advantage of this system is that the direct determination of Pb in the sample can be carried out in the aqueous phase. The maximum absorption wavelength was 530 nm, the apparent molar absorptivity ε = 2.25 × 104 L · mol-1 · cm-1, and Ph (Ⅱ) ) Complies with Lambert-Beer’s law in the range of 0-3.0 μg · ml-1. To o-phenanthroline, NH4SCN, potassium sodium tartrate joint masking agent, to eliminate the interference of common metal ions. This method is rapid, stable and easy to operate. It avoids the cumbersome operation of using toxic chemicals such as potassium cyanide and extraction. Has been used to determine tap water, snow and human hair lead content, the results are satisfactory.