Intercomparison of Boron Isotope and Concentration Measurements. Part II: Evaluation of Results

Abstract

The Istituto di Geoscienze e Georisorse (IGG), on behalf and with the support of the International Atomic Energy Agency (IAEA), prepared eight geological materials (three natural waters and five rocks and minerals), intended for a blind interlaboratory comparison of measurements of boron isotopic composition and concentration. The materials were distributed to twenty seven laboratories ‐ virtually all those performing geochemical boron isotope analyses in the world ‐which agreed to participate in the intercomparison exercise. Only fifteen laboratories, however, ultimately submitted the isotopic and/or concentration results they obtained on the intercomparison materials. The results demonstrate that interlaboratory reproducibility is not well reflected by the precision values reported by the individual laboratories and this observation holds true for both boron concentration and isotopic composition. The reasons for the discrepancies include fractionations due to the chemical matrix of materials, relative shift of the zero position on the δ11B scale and a lack of well characterized materials for calibrating absolute boron content measurements. The intercomparison materials are now available at the IAEA (solid materials) and IGG (waters) for future distribution.

Matrix effects during laser ablation MC ICP-MS analysis of boron isotopes in tourmaline

“…Several analytical technique and inter-laboratory comparisons have been carried out to identify the potential source of analytical uncertainties. Tonarini et al and Gonantini et al 8,17 showed a signicant spread in results and poor agreement between different laboratories. The source of the observed variations in their study was likely related to the specic techniques used for boron extraction and purication or to differences in analytical procedures.…”

“…The sample B4 was used for an inter-laboratory comparison study. 8,17 These four tourmalines represent some of the very best characterised materials for in situ analysis of boron isotopes that are presently available to the geoanalytical community. Four additional samples (EZ-272, JS-82N-1, JS-82A-1A, and EB-67-90) are from the boron isotopic study by Palmer and Slack.…”

Boron isotope ratio (δ11B) measurements in Water Framework Directive monitoring programs: comparison between double focusing sector field ICP and thermal ionization mass spectrometry

“…Seawater (IAEA-B1) is purified regularly in the same way in order to check for a possible chemical fractionation due to an uncompleted recovery of boron, and to evaluate the accuracy and reproducibility of the overall procedure. [39][40][41] Reproducibility was obtained by repeated measurements of the NBS951, accuracy and reproducibility are controlled with the analysis of the IAEA-B1 seawater standard.…”

Fluid/rock interaction and mass transfer in continental subduction zones: constraints from trace elements and isotopes (Li, B, O, Sr, Nd, Pb) in UHP rocks from the Chinese Continental Scientific Drilling Program, Sulu, East China

“…Data given in Table 4 have been corrected to NBS 951 that passed the entire chemical separation procedure having a d 11 B value of -0.05 ± 0.23 % (1sd) that reproduces the untreated standard value. The precision and accuracy were estimated based on the analysis of eight independent dissolutions for IAEA standard B5 (basalt) that gave a d 11 B value of -4.39 ± 0.53% (1sd), which is well in the range of published data (Gonfiantini et al 2003).…”