EVALUATION OF SECONDARY CATHODES FOR GLOW-DISCHARGE MASS-SPECTROMETRYANALYSIS OF DIFFERENT NONCONDUCTING SAMPLE TYPES

The use of different secondary cathodes is evaluated for the analysis of solid, nonconducting samples by means of de glow discharge mass spe ctrometry. Optimum discharge conditions and analytical characteristics are reported for the analysis of a compacted iron ore sinter and a so lid glass sample, both with known composition. These conditions seem t o differ significantly for the two samples under consideration. This d ifference is assumed to be caused mainly by the electrical characteris tics of the sample. The electrical resistivity of the sample is indeed found to be an important factor, determining the capabilities of the technique, especially with respect to the detection power.