抄録
The purposes of these experiments are selection of internal standard element and suppressive effects of spectrochemical buffers for analysis of a low purity metallic silicon (99∼97%).
As to an internal standard spectral line, there are no suitable silicon spectral lines revealing optimum intensity in the measuring spectral region. So the authors selected strontium with consultation of the Ahrens’s and others.
The silicon oxide band spectrum and background emission make an analysis difficalt when metallic silicon powder is excited alone in the air. But an addition of graphite powder caused a repressing effect of background and a suppressive effect of selfabsorption of SrI2932Å spectral line. The suppressive action on graphite powder matrix was attributed to the formation of silicon carbide, strontium carbide and silicate strontium. This fact made clear by X-Ray diffractive analysis of residues after discharge. But the addition of potassium carbonate and sodium chloride interfered with the formation of carbide and silicate strontium. Germanium dioxide attributed to the enhancement of silicon spectral lines.
Consequentry, it was indicated that the impurity of the low purity metallic silicon could be analysed with good accuracy by addition of strontium carbonate 1/5 times and graphite powder 5 times the weight of sample.
