Determination of Trace Silicon in High Purity Aluminium by Molybdosilicic Acid Blue Spectrophotometry after Fluoride Separation

Abstract

The amount of impurity silicon in high-purity aluminium is far below the detection limit of the JIS analytical method. So, the possibility of the determination by molybdosilicic acid blue spectrophotometry after fluoride separation has been studied. Although the presence of matrix aluminium disturbs the quantitative formation of the silicon tetrafluoride to be analyzed, the optimization of analytical conditions such as concentration and amount of hydrofluoric acid enables the determination of sub-ppm level silicon with the detection limit of 0.17 ppm.