钼蓝分光光度法快速测定硅在硅铝钙钡合金中的应用

Fast Determination of Silicon in Silicon-aluminum-calcium-barium Alloy by Molybdenum-blueness Spectrophotometry

将经典的氟硅酸钾沉淀碱滴定法改为钼蓝分光光度法快速测定硅。试样熔融酸化浸取，定容后，在0．15—0．6mol／L的微酸性溶液中，钼酸铵与硅酸作用生成黄色硅钼络离子，以草酸配位铁使溶液透明并破坏磷、砷等元素与钼酸铵生成的杂多酸，消除其干扰。用硫酸亚铁铵还原剂将生成的黄色硅钼络离子还原为硅钼蓝，其蓝色的强度与硅含量成一定比例关系，借此可用分光光度法测定硅含量，方法选择性强，且缩短了分析周期。

The classical potassium fluosilicate precipitated alkali titration method was changed to molybdenum-blue-ness spectrophotometry to fast determine silicon. After the sample was molten and acid leached, constant volumed, in 0. 15 - 0. 6mol/L slight acidish solution , ammonium molybdate and silicic acid reacted to form yellow silicon-molybdenum complex ion , oxalic acid was used to＇coordinate iron to make the solution transparent and destroy heteropoly acid formed by elements like phosphor and arsenic and ammonium molybdate to eliminate its disturbance . Then the reducing agent ammonium ferrous sulphate was used to reduce the formed yellow siliconmolybdenum complex ion to silicon-molybdenum-blueness, the strength of blueness of which is proportional to the content of silicon, by which the spectrophotometry can be used to determine the content of silicon. The method is strong in selectivity and also shortens its analytical cycle.