示波极谱法测定谷物中的痕量铅、镉

Continous determination of Pb,Cd in cereals with polargraphy catalytic method

本文报道了应用国产示波极谱仪测定多种谷物样品中痕量铅、镉的方法。铅、镉离子在碘化钾的无机酸介质中,于—0.66V,—0.78V(VsSCE)处有灵敏的导数波。线性范围分别为:Pb0.00—0.20μg/mI;Cd0.00—0.40μg/ml,检出限分别为:Pb0.3ng/ml;Cd0.1ng/ml。并应用多种标准参考物质对本法的准确性、重现性进行了评价,所得结果均在标准值范围内。回收率、重现性良好,可用于谷物样品中痕量铅、镉的测定。

Continous Determination of Pb,Cd in Cereal with Polargraphio Catalytic method. The contents of Pb,Cd in Cereal foods were determined with polargrap hic catalystic method using of the solut ions of HCI,H_3PO_4,KI as medium. The peak potentials of Pb,Cd were-0.64V and-0.78V(Vs SCE)and peak heights were linearly proportional to the concentration over arange of 0-0.2 μg/ml and0-0.4μg/ml repectively.The lower limit for determination of all the two elements were 0.2ng/ml.The recovery rate were 102% and 101% and coefficient of variation were 1.2—11.2%.This method was accurate and suitable for operation.