密闭消解磷钼蓝光度法测定多晶硅中磷

采用密闭消解多晶硅样品，然后利用磷钼蓝光度法测定多晶硅中磷含量。探讨了酸度、显色剂用量、还原剂用量等因素对测定的影响，并优化了实验参数。在最大吸收波长829 nm处，磷的线性范围为0~4.0 μg/mL，相关系数为0.999 8，检出限为0.04 μg/mL。用本文确定的方法测定多晶硅样品中磷时，大量硅在溶样时加入氢氟酸挥发而除去，过量的氢氟酸用硼酸络合，对磷的测定没有影响。该方法操作简便，具有较高的灵敏度，样品中磷分析结果的相对标准偏差为2.5%～3.5%，加标回收率在93.3%～99.8%之间。

Determination of phosphorus in polycrystalline silicon by phosphorus molybdenum blue spectrophotometry with closed digestion

The polycrystalline silicon sample was digested in a closed system. Then, the content of phosphorus in polycrystalline silicon was determined by phosphorus molybdenum blue spectrophotometry. The effect of several factors including acidity, dosage of colouring agent and reducing agent on determination was discussed to optimize the experimental parameters. At maximum absorption wavelength of 829 nm, the linear range of phosphorus was 0-4.0 μg/mL with correlation coefficient of 0.999 8. The detection limit was 0.04 μg/mL. In the determination of phosphorus in polycrystalline silicon sample by this method, large amounts of silicon were removed during sample dissolution by adding hydrofluoric acid, and excessive hydrofluoric acid was complexed with boric acid, so that the determination of phosphorus was not affected. The proposed method was simple in the operation,and had relatively high sensitivity. The relative standard deviations （RSD） of analytical results of phosphorus in sample were 2.5 %-3.5 %, and the recoveries of standard addition were 93.3 %-99.8 %.