分光光度法测定高纯氧化铝中痕量硅方法改进

Improvement of spectrophotometric method for the determination of trace silicon in high purity alumina

采用硅钼蓝法测定氧化铝中硅的含量,用硫酸(1+5.5)作为溶剂溶解氧化铝粉末,显色剂采用钼酸铵与硅络合,再用L-抗坏血酸还原,并加入2.0 ml柠檬酸,在波长815 nm处用3 cm比色皿测定硅的含量。在50 ml体系中,Si含量在低于20μg时与吸光度呈良好的线性关系,r^2=0.99696,用该法成功检测了氧化铝中痕量硅元素的含量,检测范围为0.64~15μg/g,标准偏差小于8%,标准回收率在93%~105%之间。该方法用于检测高纯三氧化二铝粉末,成本低廉,精密度高,其推广使用对蓝宝石生产具有重要意义。

Silicon content in alumina was determined by molybdenum blue method.Alumina powder was dissolved with sulfuric acid(1+5.5)as solvent.Ammonium molybdate was complexed with silicon as colorant,and then reduced by L-ascorbic acid,and added with 2.0 ml citric acid.The siliconcontent was measured in a 3 cm cupel at the wavelength of 815 nm.In 50 ml system,the linear relationship between silicon content and absorbance is good when the content is less than 20μg,and the correlation coefficient of r2 is 0.99696.The content of Trace Silicon in alumina is successfully determined by this method.The detection range is 0.64-15μg/g,the standard deviation is less than 8%,and the standard recoveryrate is from 93%to 105%.This method is used to detect high purity aluminium trioxide powder with low cost and high precision.Its popularization is of great significance to sapphire production.