极谱分析法测定生活固体废弃物中痕量铅

Determination of Trace Lead in Integrated Solid Wastes by Polarography

采用浓硫酸炭化、硝酸-高氯酸消解废弃报纸、导购彩报和废弃尼龙麻袋样品,在6%溴化钾、1%酒石酸钾钠、0.7%的盐酸、5%磷酸、2%盐酸羟胺、3%(体积)三乙醇胺混合底液中,以单扫描极谱法测定样品中痕量铅的含量.结果表明,铅在滴汞电极上于-0.47V(相对饱和甘汞电极)处产生一灵敏催化极谱波,极谱峰电流与铅浓度在0.2～300ng/mL范围内有良好的分段线性关系,检出限为0.16ng/ml.该方法的RSD为5.6%～7.1%,加标回收率为89%～105%.本法快速简便,准确度高,用于实际样品测定的结果满意.

A new polarography method for the determination of trace lead in waste newspaper,advertisement paper,and nylon gunnysack sample is described.The treatment of the samples was done by carbonizing the samples using strong sulfuric acid at first and then digesting using nitric acid-perchloric acid solution.The supporting electrolyte solution used in this measurement is established as 6%KBr-1%KNaC_4H_4O_6·4H_2O-0.7%HCl-5%H_3PO_4-2%NH_2OH·HCl-3%N(CH_2CH_2OH)_3.The peak potential of lead is-0.47V(vs.SCE).The peak height is linear with lead concentration in the range of 0.2~300ng/ml.The detection limit is 0.16 ng/ml,the RSD is in the range of 5.6%~7.1%,and the recovery is 89%～105%.This method is rapid and simple,and has been used to determine trace lead in integrated solid wastes with satisfactory results.