钼蓝光度法测定电解金属锰中硅含量的优化试验

Optimization Test for Determination of Silicon Content in Electrolytic Manganese by Molybdenum Blue Photometry

试样用硫酸分解,硅酸与钼酸铵生成可溶性的黄色硅钼杂多酸,加入氢氟酸消除磷、砷等杂质的影响,用硫酸亚铁铵还原生成硅钼蓝,810 nm波长条件下进行紫外分光光度测定电解金属锰中硅的含量。对该方法的分析条件试样称取量进行优化试验。试验结果表明:该方法优化后,测定操作简单,缩短测定时长;重复测定高、中、低结果相对标准偏差为1.41%~4.12%;加标回收率在97.0%~105.0%之间;优化后方法精密度好、重复性好、回收率高、可行性高,适用于电解金属锰中硅含量的测定。

The sample was decomposed by sulfuric acid.The reaction of silicic acid and ammonium molybdate generated soluble yellow Si-Mo heteropoly acid,and hydrofluoric acid was added to eliminate the influence of phosphorus,arsenic and other impurities.Then,ammonium ferrous sulfate was reduced to Si-Mo blue.The silicon content in the electrolytic manganese metal was determined by ultraviolet spectrophotometry under the condition of 810 nm wavelength.The optimum test was carried out on the weighing of the analytical conditional sample.The experimental results shew that the optimized method was simple and can shorten the testing time.The RSD was 1.41%~4.12%for high,medium and low results.The recovery rate was between 97.0%and 105.0%.The optimized method has good precision,repeatability,recovery and feasibility,and is suitable for the determination of silicon content in electrolytic manganese metal.