目前国内对糕点中的微量铅的测定常用原子吸收分光光度法和双硫腙比色法。但仪器昂贵或操作费时。用催化极谱法测定糕点中微量铅,其波高与浓度在0.05～1.00μg·ml~(-1)范围内线性关系良好,检出下限为0.05μg·ml~(-1),具有操作简便、快速、准确、灵敏度高。 1 分析步骤 1.1 样品消化取糕点捣碎混匀,称取1.00g于三角烧瓶内,加水5.0ml。硝酸3.0ml,高氯酸2.0ml,盐酸2.0ml。电热板上消化为白色残渣,同时作试剂空白试验。 1.2 样品测定于样品和试剂空白三角烧瓶内加入底液(用去离子水配成含5%盐酸,1.5%酒石酸,0.5%碘化钾, At present, the domestic determination of trace lead in cakes commonly used atomic absorption spectrophotometry and dithizone colorimetry. However, the instruments are expensive or time-consuming to operate. The determination of trace lead in cakes by catalytic polarography showed a good linear relationship between wave height and concentration in the range of 0.05-1.00 μg · ml -1 with a detection limit of 0.05 μg · ml -1. Fast, accurate, high sensitivity. 1 Analysis step 1.1 sample digestion Take mashed cake mix, weighed 1.00g in conical flask, add water 5.0ml. 3.0 ml of nitric acid, 2.0 ml of perchloric acid and 2.0 ml of hydrochloric acid. Digestion on the hot plate for the white residue, at the same time as a reagent blank test. 1.2 Determination of samples In the sample and reagent blank conical flask was added to the bottom solution (with deionized water to make up with 5% hydrochloric acid, 1.5% tartaric acid, 0.5% potassium iodide,