誘導結合プラズマ質量分析法による高純度石英中微量元素の定量

抄録

Determination of Li, B, Mg, Cr, Mn, Ni, Co, Cu and Zr in high-purity quartz by inductively coupled plasma mass spectrometry (ICP-MS) was studied. Effect of mannitol, dulcitol or solbitol on suppression of boron volatillization from hydrofluoric acid solutions was examined. Boron volatillization was found to be completely suppressed by addition of 500-fold molar excess of dulcitol to boron or 1 000-fold molar excess of mannitol. Even 1 000-fold molar excess of solbitol was not sufficient for complete suppression. These organic compounds introduced to ICP-MS caused mass interference due to ⁴⁰Ar¹²C with ⁵²Cr and reduction of intensity by carbon deposition on the sampling cone orifice. Therefore the following analytical conditions were employed.
(1) 2 mg of dulcitol was added.
(2) Measurements were performed by deviding into 2 groups ; one group with dulcitol for Li, B and Mg determination, and the another without dulcitol for Cr, Mn, Ni, Co, Cu and Zr determination.
(3) Be and V were added as the internal standards.
The limits of detection (3σ) with present method were 0.0005 0.01 ppm. The proposed method was applied to the detemination of Li, B, Mg, Cr, Mn, Ni, Co, Cu and Zr in the practical quartz with satisfactory results.