The absorptiometric determination of silicon in water. Part VII. Improved method for determining the total silicon content of high-purity water

Abstract

A method is described for determining the total silicon content of high-purity waters; this method allows more precise results to be obtained than the method given in Part III of this series. Silicon in the water is initially concentrated on a mixture of finely ground cation and anion-exchange resins, which are then ignited and fused with sodium carbonate. The resulting melt is dissolved in water and silicate is determined absorptiometrically as the reduced β-molybdosilicic acid. The standard deviation of analytical results for 1-litre samples containing between 0 and 100 µg of silica was about 3 µg of silica. Ten analyses and the necessary blank determinations can be carried out in 8 hours.