Boron determinations of silicate reference rocks by the isotope dilution method in a high-background environment

Abstract

of rock samples (Yonezawa et al., 1999; Sano et al., 1998, 1999, 2001; Miyoshi et al., 2010; Shinjoe et al., 2013). Sano et al. (1998, 1999) reported that relative standard deviations (% RSD) of replicate analyses of standard rocks were better than 5% for the wide range of boron concentrations of 8–160 ppm. After the nuclear power plant accident in 2011, neutron radiation experiments were halted in Japan. Boron determination was attempted in a high background environment in this study. An ICP-MS used for boron determinations was installed in a laboratory where laser ablation ICP mass spectrometry analyses on glass bead samples fused with LiBO4 was conducted with another ICP-MS. The author investigated effective methods to reduce the influence of a high background on boron peaks. Three analytical methods were compared to improve the accuracy of boron determination. When the concentration of an element is measured using a sensitivity method that compares a signal intensity of an element in a sample solution with that in a standard solution, an internal standard element is often doped to the sample solution to correct the influence of the sample-derived matrix. The internal standard element is selected from elements that are not included in the sample solution and which have a similar mass number to that of the element to be analyzed. Finding a suitable internal standard element is difficult when light elements such as Li, Be, and B in silicate rock samples are determined. Gotan et al. Boron determinations of silicate reference rocks by the isotope dilution method in a high-background environment