ANALYSIS OF ALUMINUM-OXIDE POWDER BY GLOW-DISCHARGE MASS-SPECTROMETRY WITH LOW-MASS RESOLUTION

A laboratory-developed glow discharge mass spectrometry system with low mass resolution has been applied to the analysis of electrically non-conducting aluminium oxide powder. In order to prepare a massive conducting sample, aluminium oxide powder was mixed and compacted with copper powder as host matrix in a mass ratio of 1:5. Argon and neon were used as alternative working gases of the discharge. Influences of operational parameters were studied for both gases. Single-ion monitoring profiles of the pre-burning phase indicate a transition from an initial high-current phase with intense contributions from molecules, to a final phase of approximation to equilibrium with higher intensities of analyte ions and lower contributions from molecules. Calibration was performed for several elements; detection limits in the region of a few mug g-1 were obtained for elements for which determination was not limited by interferences arising from the discharge or from impurities of the host matrix. In several stages of the work, influences of sample pre-treatment and sample structure to elemental sensitivities were observed.