Application of radiofrequency glow discharge-optical emission spectrometry for direct analysis of main components of glass samples

Abstract

An internal standard calibration methodology for radiofrequency glow discharge optical emission spectrometry (rf-GD-OES) has been evaluated for the quantitative analysis of glass samples. Glasses of very different composition and thickness (from 2.8 to 5.8 mm thick) were used for calibration. The absence of spectral interferences from sputtered oxygen was first investigated. For calibration, Si was selected as the internal standard and, when plotting intensity ratios (I_x/I_Si) versus concentration ratios (C_x/C_Si), linear graphs over the entire range of tested concentrations were obtained. In all cases, concentrations of the oxides of different elements have been used instead of elemental concentrations as is habitually done for the analysis of conductors. Thus, the proposed methodology allows us to quantify the oxygen indirectly without measuring its emission intensity. In addition, the internal standard calibration procedure was applied for the determination of the glass major components (SiO₂, Na₂O, CaO, MgO, Al₂O₃ and K₂O) by rf-GD-OES in two glass samples and results showed good agreement with the certified values.