Radio frequency glow discharge optical emission spectrometry (rf-GD-OES) analysis of solid glass samples

Abstract

The analytical characteristics of rf-GD-OES for the elemental analysis of bulk solid glass specimens are investigated. Studies are carried out to evaluate the role of the major operating parameters—discharge power and pressure, use of an external argon (bath) gas, sample thickness, and internal standard normalization. Plasma stabilization and signal response are optimized at 30 W rf power and 6 Torr as suggested by the relative standard deviation of the background (RSDB) and signal to background ratio (S/B) values respectively. Basic figures of merit are further improved with the introduction of the argon (bath) gas, decreasing by a minimum of 25% of the original %RSD values of the sample-to-sample S/B ratios. Variations in analyte signal intensities due to differences in sample thickness are quantitatively corrected using internal standard (normalization) based on the relative response of the Ar(I) optical emission. Limits of detection (LOD) are on the single µg g−1 level, which are comparable to some other OES methods. Linear calibration curves over the range of ∼1–500 ppm are obtained using the Ar(I) signal emission as the normalizing internal standard.