Separation and determination of sulfide sulfur and sulfate sulfur in soda lime silicate glass

ABSTRACT The quantities of sulfide sulfur and sulfate sulfur and the average valence of sulfur in soda lime silicate glass are important because they affect the number of bubble defects and color of the glass. In this paper, we describe and demonstrate a new determination method of sulfide and sulfate in glass. This method consists of decomposition of a glass material and the separation and determination of sulfide and sulfate. Hydrochloric acid and hydrofluoric acid decompose the material in a vessel. The vessel is combined with a series of traps. Hydrogen peroxide and sodium hydroxide in the traps absorb hydrogen sulfide that volatilizes during decomposition. This method allows for the determination of sulfate remaining in the vessel and the trapped sulfide, respectively. The method is tested on two glass reference materials with commonly accepted testing equipment. The sums of sulfide and sulfate are within the range of each certified value. The average valences of sulfur, which are calculated from the quantities of sulfide and sulfate, are in good agreement with the average valences of sulfur obtained by wavelength-dispersive X-ray fluorescence spectrometric analysis.