Japan Geoscience Union Meeting 2018

Presentation information

[JJ] Poster

S (Solid Earth Sciences) » S-CG Complex & General

[S-CG61] Ocean Floor Geoscience

Wed. May 23, 2018 10:45 AM - 12:15 PM Poster Hall (International Exhibition Hall7, Makuhari Messe)

convener:Kyoko Okino(Atmosphere and Ocean Research Institute, The University of Tokyo)

[SCG61-P16] A simple determination of major- and trace-element composition for peridotite by ICP-MS: an application of acid-digested fused-glass bead

*Norikatsu Akizawa1, Akira Ishikawa2, Tetsu Kogiso3 (1.Atmosphere and Ocean Research Institute, The University of Tokyo, 2.Graduate School of Arts and Sciences, The University of Tokyo, 3.Graduate School of Human and Environmental Studies, Kyoto University)

Keywords:whole-rock composition, ICP-MS, XRF, lithium tetraborate glass

A simple analytical procedure for determination of whole-rock major- and trace-element composition by inductively coupled plasma-mass spectrometer (ICP-MS) using fused-glass bead (sample + lithium tetraborate) is presented. In the case of peridotite, chromite is one of the minerals resistant to acids and interferes with accurate and reproducible determination of whole-rock composition. Such resistant minerals were not observed in the fused-glass beads prepared here, suggesting complete digestion of the samples including chromites. The fused-glass beads were properly dissolved into a nitric acid solution to analyze with sector magnetic field ICP-MS (ICP-SFMS) and Q-pole mass filter ICP-MS (ICP-QMS). The analytical procedure was optimized and evaluated with five geological reference materials, BIR-1, JB-3, JGb-1, JP-1, and W-2. The results demonstrate that the whole-rock compositions were reasonably quantified with the analyses of ICP-MSs.

Since only fused-glass beads are required as an analytical target to determine whole-rock major- and trace-element composition, the sample amount consumed through the series of analytical procedure can be constrained to a minute amount (e.g. <0.4 g). The analytical procedures with ICP-MSs are considered appropriate for tiny and/or precious samples, such as xenoliths and samples collected by dredging, diving, and drilling from the world’s ocean basins.