单扫描示波极谱法测定生脉注射液及其中药材中的铅和镉

摘要

A method of successive determination of Pb（ Ⅱ ） and Cd（ Ⅱ ） in the traditional Chinese medicine sam-ple by Single Scan Oscillographic Polarography was presented in this paper. In the solution of HC1-KI-NaC4HsO6-C6HgO10, sensitive and sharp reduction wave peaks were observed at-0.502 V（vs.SCE for Pb^2＋ ） and at-0.632 V（vs.SCE for Cd^2＋ ）.The peak current was proportional to the concentration of Pb（ Ⅱ ） and Cd（ Ⅱ1 ） in range of 0.01 μg·ml^-1~l.5 μg·ml^-1＇ for Pb^2＋ and 0.01 μg·ml^-1l.6 μg·ml^-1 for Cd^2＋respectively. The linear regression equation was Iy=882.3Cx＋29.36, the related coefficient was 0.9998（Pb^2＋） and Iy=617.1Cx ＋28.25, the related coef-ficient was 0.9995（Cd^2＋）.The lowest detection limit was 0.001 μg·ml^-1 for Pb^2＋ and 0.001 μg·ml^-1 for Cd^2＋.The method was applied to determination of Pb^2＋ and Cd^2＋ in the sample. The RSD obtained was 1.123%-1.653% and the recovery was 96.3%-102.1%. The methods do not need to be deoxidized and have the advantages of simplici-ty, quickness, high accuracy and satisfactory results.%采用三电极系统研究了铅（Ⅱ）离子、镉（Ⅱ）离子的极谱行为，在盐酸-酒石酸钠-碘化钾-抗坏血酸混合底液中采用单扫描示波极谱法可测得Pb^2＋、Cd^2＋的灵敏极谱峰，波峰电位分别为-502mV和-632mV（vs．SEE），铅离子的线性范围为0．01—1．5μg·ml^-1，最低检出限为0．001μg·ml^-1，线性回归方程为Iy=882．3Cx＋29．36，相关系数r=0．9998，镉离子的线性范围为0．01—1．6μg·ml^-1，最低检出限为0．001μg·ml^-1，线性回归方程为Iy=617．1Cx＋28．25，相关系数r=0．9995．采用本法测定生脉注射液及其中药材中的铅和镉含量，样品回收率在96．3％-102．1％之间，相对标准偏差RSD在1．12％～1．65％之间．此方法无须除氧，简单、快捷、准确度高，结果满意。