利用全微机化示波极谱法测定复杂地质样品中锡

Determination of Sn in the Complex Geological Sample by Microcomputer Oscillographic Polarography

过氧化钠熔融分解样品,热水提取,用EDTA消除钙、镁等的影响,溶液酸化后用氯化钡沉淀铅,动物胶凝聚硅而消除干扰。分取澄清溶液,加入氯化钠及少量抗坏血酸作为底液,进行示波极谱测定,峰电位约为-0.52V(对饱和甘汞电极)。锡含量在2.5—40.0μg/mL之间时,峰高与浓度呈线性关系。测定范围0.010%—8.00%。方法用于国家一级标准物质中Sn的测定,测定结果与推荐值相符,对Sn分析的RSD(n=6)<5%。

The sample was decomposed by sodium peroxide, and distilled by hot water. The interference of calcium and magnesium was eliminated by EDTA, lead was precipitated by barium chloride, and the interference of silicon was eliminated by animal glue agglomeration. Tin was determined in sodium chloride with ascorbic acid as electrolyte solution by oscillographic polarography. The peak potential is about -0. 52V （vs SCE）. The linear range is 2. 5-40μg/ml. （0. 010- 8.00%） with RSD of〈5%（n=6）.