Analysis of rare earth elements in standard samples of granitic rocks by inductively coupled plasma mass spectrometry after acid digestion and alkali fusion

Abstract

Acid digestion and alkali fusion were applied to sample preparation of granitic rocks for the rare earth elements (REE) analysis by inductively coupled plasma mass spectrometry (ICP-MS). Granitic rock samples were decomposed by conventional rock-dissolution techniques, and the residues were fused with the mixture of Na₂CO₃ and H₃BO₄. The fusion ensured complete dissolution of acid-resistant minerals. Appropriate amounts of major elements were added to the REE calibration standard solution for matrix matching. The conditions of the instrument were adjusted to minimize the formation of the oxide molecular ions. Fourteen REE in three standard samples of granitic rocks were determined successfully.