LA-ICP-MSによる石英中の微量元素分析(都市基盤デザイン工学科,工学部創設40周年記念号)

Abstract

LA-ICP-MS was applied to analyze minor elements in quartz from volcanic rocks at the Unzen and the Kuju districts in Kyushu. Since the intensity of its signals varies extremely with time, an internal standard which is included with a constant amount stoichiometrically in the mineral under analysis is absolutely necessary (for example, Si in quartz). An idea of "equi-isotope concentration coefficient" was adopted. The results show that the minor elements range from several up to a few thousand ppm, and that the tetrahedral Al which substitutes Si keeps electric balances with alkaline ions of Li+Na+K.