Acid decomposition procedure for the spectrophotometric determination of silica in rocks and minerals at room temperature

Abstract

An acid decomposition procedure at room temperature for the spectrophotometric determination of silica in rocks and minerals is described. The sample solution is prepared by treatment with hydrofluoric acid and aqua regia at room temperature. Unreacted fluoride ions are complexed with boric acid and the silica is determined by the molybdenum blue method. Accurate values were obtained for a number of international reference standards. The entire procedure is carried out at room temperature. Only plastic ware is used for the decomposition of the samples. The method is thus ideal for large batch analyses. © 1992.