open access

https://hdl.handle.net/2115/62042

Quantitative analyses of Rb, Sr, Sm and Nd for GSJ rock reference samples (JB-1a, JGb-1 and JG-1a) by isotope dilution method using thermal ionization mass spectrometer

日本語

JG-1a

2004-09-30

Division of Earth and Planetary Sciences (Earth and Planetary Materials Science) Graduate School of Science Hokkaido University

HUEPS Technical Report

3

1-12

Rb, Sr, Sm and Nd concentrations of geological samples have been determined by isotope dilution method using thermal ionization mass spectrometer (Finnigan MAT 262) at Division of Earth and Planetary Sciences, Hokkaido University. In order to evaluate reproducibility and accuracy of the analyses, we conducted replicate experiments for three GSJ rock reference samples (JB-1a, JGb-1 and JG-1a). The results of five to six separate analyses are as follows (concentrations in ppm with standard deviation, 1S.D.): Rb = 39.39 ± 0.19, Sr = 460.6 ± 3.4, Sm = 5.30 ± 0.03, and Nd = 27.20 ± 0.15 for JB-1a; Rb = 5.93 ± 0.22, Sr = 341.1 ± 1.5, Sm = 1.49 ± 0.01 and Nd = 5.44 ± 0.04 for JGb-1; Rb = 182.2 ± 0.5, Sr = 186.7 ± 0.5, Sm = 4.58 ± 0.22 and Nd = 20.12 ± 1.29 for JG-1a. The results show good reproducibility. The comparatively poor reproducibility of Sm and Nd in JG-1a may be attributed to heterogeneity in amount of REE-bearing accessory minerals in the sample prepared by GSJ. Overall, the results are in well agreement with the “recommended values” of Imai et al. (1995), suggesting that our analyses have good accuracy. Of course, accuracy of analyses directly depends on accuracy in concentrations of analyzed elements of spike solutions. Therefore, reexamination of spike compositions might be necessary for stricter evaluation. During this study, analytical results of 87Sr/86Sr and 143Nd/144Nd analyses were as follows: 87Sr/86Sr = 0.704082 ± 0.000019 (1S.D., n = 9) and 143Nd/144Nd = 0.512780 ± 0.000014 (1S.D., n = 9) for JB-1a, 87Sr/86Sr = 0.705258 ± 0.000034 (1S.D., n = 3) and 143Nd/144Nd = 0.512655 ± 0.000009 (1S.D., n = 3) for JGb-1 and 87Sr/86Sr = 0.710964 ± 0.000081 (1S.D., n = 3) and 143Nd/144Nd = 0.512368 ± 0.000003 (1S.D., n = 3) for JGb-1. 87Sr/86Sr of SRM987 was 0.710202 ± 0.000023 (1S.D., n = 11) and 143Nd/144Nd of JNdi-1 was 0.512105 ± 0.000010 (1S.D., n = 9).

報告書

Not Applicable (or Unknown)

1343-0912