Solid sampling system for direct analysis of glass fibres by direct current plasma atomic emission spectrometry

Abstract

A solid sampling technique has been developed and tested for elemental analysis of solid glass materials by direct current plasma atomic emission spectrometry. The samples were drawn into thin fibres and fed by a specially designed sample introduction device into the direct current plasma jet. The preliminary experiments showed that for analysis of low melting-point (<700 °C) glass materials (e.g., soda lime glass) an oscillating or pulsating sample insertion technique had to be used in order to avoid bending and sagging of the fibres. For glasses with higher melting-points (e.g., borosilicate glass) a continuous feeding of the fibre worked satisfactorily. Glass fibres that have a high silica content, such as optical fibres, with high melting-points (>1500 °C) can thus be analysed with good accuracy using the continuous sample introduction mode. The main advantage of continuous feed is that the integration mode of the instrument can be used, which improves considerably the precision and accuracy of the measurements.