电位溶出法同时测定锌镉铅的研究

SIMULTANEOUS POTENTIAL STRIPPING VOLTAMMETRIC DETERMINATION OF ZINC CADMIUM AND LEAD

探讨了一种同时测定锌、镉、铅的溶出分析方法。在 0 .0 17mol·L- 1H2 SO4 HNO3混合酸介质中 ,用同位镀汞法在电位 - 1.5 0V条件下电解富集 60s ,锌、镉、铅分别在 - 1.0 7,- 0 .65及 - 0 .4 6V处有一良好的溶出峰 ,锌浓度在 0 .0 0 2 5～ 0 .0 2 5 μg·ml- 1,镉和铅在 0 .0 0 2 5～ 0 0 2 3μg·ml- 1范围内与峰高呈良好的线性关系 ,检出限锌为 0 .0 0 0 75 μg·ml- 1,镉和铅为 0 .0 0 0 70 μg·ml- 1。方法操作简便、快速、准确。用于环境水质标样、纯净水及自来水中锌、镉、铅的同时测定 。

A method of simultaneous determination of zinc, cadmium and lead in environmental water sample and drinking water by potential stripping voltammetry is described in this paper. The above mentioned cations are enriched for 60s at -1.50V ( vs .SCE) in a 0.017mol·L -1 H 2SO 4 HNO 3 mixed acid medium by the isochronous mercury plating method. Their stripping potential peak appear at -1.07V ( vs .SCE) for Zn, -0.65V ( vs .SCE) for Cd, and -0.46V ( vs .SCE) for Pb. The linear relationship between peak heights and concentrations of these three cations are found in the following ranges: for Zn: 0.0025～0.025μg·ml -1 ; for Cd:0.0025～0.023μg·ml -1 ; for Pb:0.0025～0.023μg·ml -1 . Their detection limits are found to be 0.00075μg·ml -1 for Zn and 0 00070μg·ml -1 for both Cd and Pb.