Determination of low content silicon dioxide in fluorite by inductively coupled plasma atomic emission spectrometry

An inductively coupled plasma atomic emission spectrometry (ICP-AES) for the determination of low content silicon dioxide in fluorite was studied. The sample was liquated with a mixed flux of unhydrous sodium carbonat and bonic acid, soaked out with hydrochloric acid (1 + 5), and then the sample solution was measured by inductively coupled plasma atomic emission in system of nebulizer and torch resistant to hydrofluoric acid. Conditions of sample processing, instrument measurement, interferences of coexisting elements and matrix were tested. The optimum analytical wavelength of 212.412 nm was selected for silicon dioxide in accordance with comparative result of the sensitivities, interferences and correlation coefficients of all analytical wavelengths. The method has been applied to the determination of silicon dioxide (0.70%-5.00%) in fluorite reference materials with relative standard deviations of 0.51%-1.46%. The determination results are consistent with the certified values or those of national standard method.