This new comprehensive mineral-chemical characterisation of the Happy Jack uraninite has discovered additional information regarding matrix effects and trace element homogeneity, relevant to proposals that it could serve as a reference material (RM). On the LA-ICP-MS instrumentation used, there was an absence of discernible matrix effects relative to the silicate glass NIST SRM 610. Lanthanides and Y are found to be very homogeneously distributed in Happy Jack uraninite, Zr, Nb and Ti mass fractions reproducible but only within individual fragments, and other elements still generally heterogeneous. This means that the Happy Jack uraninite can serve as a secondary RM for quality control in studies of natural uraninites. In terms of absolute accuracy and intermediate measurement precision, the Happy Jack uraninite can be used for the homogeneous elements. For elements that are homogeneous within individual fragments only, intermediate measurement precision can still be evaluated, while information values will be obtained for the generally heterogeneous elements. Two distinct groups (high vs. low Zr) were distinguished to exist among different Happy Jack fragments in association with minor variation of REE mass fractions, which possibly explains the observed (heavy) REE discrepancy between laser ablation and bulk solution ICP-MS analyses.

To examine the applicability of different leaching methods used to extract secondary oxides from silicate solids for lithium isotope (δLi) measurement, this study has conducted leaching experiments on five different types of silicate solids, including a fresh basalt, two weathered basalts, a Yellow River sediment (loess-dominated) and a shale. Four factors were assessed in the experiments: the concentration of the leaching reagent hydroxylamine hydrochloride (HH), the leaching temperature (20 °C 95 °C), the leaching time and the reagent/solid ratio. Based on elemental concentrations and Li isotopes, 0.04 mol l hydroxylamine hydrochloride (HH) in 25% acetic acid at room temperature for 1 h with 40 ml g reagent/solid ratio is recommended. At high temperatures, low δLi and high magnesium/iron ratios indicate that minerals other than secondary oxides are dissolved. With increased leaching time, there is no evidence for Li isotopic fractionation at room temperature. However, longer leaching time or increased reagent/solid ratios may increase the risk of leaching from non-oxide phases. Meanwhile, results suggest that low concentrations of HH are not sufficient to target the secondary oxides evenly, while high concentrations of HH can leach out more non-oxides. We also examined the optimal oxide leaching method within a full sequential leaching procedure (i.e., exchangeable, carbonate, oxide, clay and residual phases). Elemental concentrations show that no elements exist exclusively in oxides, so it is essential to analyse multi-elemental concentrations to verify that the leaching has accessed this phase in a given sample. Comparing secondary oxides with their corresponding solutions, we estimate the isotopic fractionation (ΔLi) is -16.8‰ to -27.7‰.

Beryllium-10 ( = 1.4 Ma) is a short-lived radionuclide present in the early Solar System. It is produced solely by irradiation reactions and can provide constraints on the astrophysical environment of the Sun's formation. Calcium- and aluminium-rich inclusions (CAIs), the first solids formed in the Solar System, show clear evidence for live Be at their time of formation, but it is unclear whether they record the same initial Be/Be ratio. In this study, we examine the secondary ion mass spectrometry methods used to determine the initial Be/Be ratio in meteoritic inclusions. Based on analyses of synthesised matrix-matched glass reference materials, we show that the effects of differing major element bulk compositions on the secondary ion yields of Be and B are minor for relevant phases. We demonstrate the importance of using the mean square weighted deviation (MSWD) to interpret the significance of the initial Be/Be value. For thirty-two CAIs, we re-calculated the regressions using literature data, finding that several have unacceptably high MSWD. We calculate the effects of possible sources of isotopic disturbance. Finally, we outline best practices for reporting Be-B data, to enable a more refined determination of the initial Be/Be ratio in the early Solar System.

Electron probe microanalyzer measurements of trace elements with high accuracy are challenging. Accurate Al measurements in olivine are required to calibrate SIMS implant reference materials for measurement of Al in the solar wind. We adopt a combined EPMA/SIMS approach that is useful for producing SIMS reference materials as well as for EPMA at the ~100 μg g level. Even for mounts not polished with alumina photoelectron spectroscopy shows high levels of Al surface contamination. In order to minimize electron beam current density, a rastered 50 × 100 μm electron beam was adequate and minimized sensitivity to small Al-rich contaminants. Reproducible analyses of eleven SIMS-cleaned spots on San Carlos olivine agreed at 69.3 ± 1.0 μg g• The known Al mass fraction was used to calibrate an Al implant into San Carlos. Accurate measurements of Al were made for olivines in the pallasites: lmilac, Eagle Station and Springwater. Our focus was on Al in olivine, but our technique could be refined to give accurate electron probe measurements for other contamination-sensitive trace elements. For solar wind, it is projected that the Al/Mg abundance ratio can be determined to 6%, a factor of 2 more precise than the solar spectroscopic ratio.

Here, we document a detailed characterisation of two zircon gemstones, GZ7 and GZ8. Both stones had the same mass at 19.2 carats (3.84 g) each; both came from placer deposits in the Ratnapura district, Sri Lanka. The U-Pb data are in both cases concordant within the uncertainties of decay constants and yield weighted mean Pb/U ages (95% confidence uncertainty) of 530.26 Ma ± 0.05 Ma (GZ7) and 543.92 Ma ± 0.06 Ma (GZ8). Neither GZ7 nor GZ8 have been subjected to any gem enhancement by heating. Structure-related parameters correspond well with the calculated alpha doses of 1.48 × 10 g (GZ7) and 2.53 × 10 g (GZ8), respectively, and the (U-Th)/He ages of 438 Ma ± 3 Ma (2) for GZ7 and 426 Ma ± 9 Ma (2) for GZ8 are typical of unheated zircon from Sri Lanka. The mean U mass fractions are 680 μg g (GZ7) and 1305 μg g (GZ8). The two zircon samples are proposed as reference materials for SIMS (secondary ion mass spectrometry) U-Pb geochronology. In addition, GZ7 (Ti mass fractions 25.08 μg g ± 0.18 μg g; 95% confidence uncertainty) may prove useful as reference material for Ti-in-zircon temperature estimates.

This study presents a new measurement procedure for the isolation of Pt from iron meteorite samples. The method also allows for the separation of Pd from the same sample aliquot. The separation entails a two-stage anion-exchange procedure. In the first stage, Pt and Pd are separated from each other and from major matrix constituents including Fe and Ni. In the second stage, Ir is reduced with ascorbic acid and eluted from the column before Pt collection. Platinum yields for the total procedure were typically 50-70%. After purification, high-precision Pt isotope determinations were performed by multi-collector ICP-MS. The precision of the new method was assessed using the IIAB iron meteorite North Chile. Replicate analyses of multiple digestions of this material yielded an intermediate precision for the measurement results of 0.73 for εPt, 0.15 for εPt and 0.09 for εPt (2 standard deviations). The NIST SRM 3140 Pt solution reference material was passed through the measurement procedure and yielded an isotopic composition that is identical to the unprocessed Pt reference material. This indicates that the new technique is unbiased within the limit of the estimated uncertainties. Data for three iron meteorites support that Pt isotope variations in these samples are due to exposure to galactic cosmic rays in space.

Excellent agreement was noted in the concentration of major and trace elements in five NIST soil reference materials (NIST SRM 2586, 2587, 2709a, 2710a and 2711a) between measurement results from wavelength dispersive-XRF and ICP-MS from two independent laboratories, and NIST certificate of analysis and literature data. We describe the variability in concentrations of up to forty-nine elements (plus loss on ignition) and provide values for up to twenty-one elements previously uncharacterised by NIST in these soil RMs. The additional characterisation provided in this investigation can be utilised to reduce the measurement bias of custom calibration routines and improve the quality of control checks developed using these NIST RMs.