The δ^60/58Ni Values of Twenty‐Six Selected Geological Reference Materials

Abstract

The high‐precision δ60/58Ni values of twenty‐six geological reference materials, including igneous rocks, sedimentary rocks, stream sediments, soils and plants are reported. The δ60/58Ni values of all samples were determined by double‐spike MC‐ICP‐MS (Nu Plasma III). Isotope standard solution (NIST SRM 986) and geological reference materials (BHVO‐2, BCR‐2, JP‐1, PCC‐1, etc.) were used to evaluate the measurement bias and intermediate precision over a period of six months. Our results show that the intermediate precision of Ni isotope determination was 0.05‰ (2s, n = 69) for spiked NIST SRM 986 and typically 0.06‰ for actual samples, and the δ60/58Ni NIST SRM 986 values were in excellent agreement with previous studies. Eighteen high‐precision Ni isotope ratios of geological reference materials are first reported here, and their δ60/58Ni values varied from −0.27‰ to 0.52‰, with a mean of 0.13 ± 0.34‰ (2s, n = 18). Additionally, SGR‐1b (0.56 ± 0.04‰, 2s), GSS‐1 (−0.27 ± 0.06‰, 2s), GSS‐7 (−0.11 ± 0.01‰, 2s), GSD‐10 (0.46 ± 0.06‰, 2s) and GSB‐12 (0.52 ± 0.06‰, 2s) could potentially serve as candidate reference materials for Ni isotope fractionation and comparison of Ni isotopic compositions among different laboratories.

Innovative two-step isolation of Ni prior to stable isotope ratio measurements by MC-ICP-MS: application to igneous geological reference materials

“…Consequently, a conservative overall uncertainty (2SD, the expanded combined uncertainty with a coverage factor of 2) of AE0.032& or AE0.016& per amu (eqn (VI)) is adopted for all d 60/58 Ni measurements presented in this study unless stated otherwise. Notably, the level of precision associated with the method presented here is similar to those achieved in previous studies (AE0.018& to AE0.089&, 2SD 6,16,27,39,40,[43][44][45][64][65][66][67][68] ).…”

“…As part of this work, a set of 14 igneous geological reference materials were subject to Ni isotopic analysis in order (1) to 6,16,34,35,39,40,[43][44][45][64][65][66][67]69 ). Our value of À0.021 AE 0.032& for BHVO-2 overlaps with 6 out of the 10 published d 60/58 Ni values within uncertainty, but is slightly lower than the average d 60/ 58 Ni from previous studies (+0.028 AE 0.070&, Fig.…”

“…a New recommended values are calculated as error-weighted average of previously published6,16,27,34,39,40,[43][44][45][64][65][66][67] and newly acquired d60/58 Ni data (using IsoplotR 58 ). For consistency, all uncertainties from other studies were re-calculated as discussed in Section 3.3 encompassing the intermediate precision obtained from both pure Ni solution and real samples.…”

Atomic spectrometry update – a review of advances in environmental analysis

“…Rapid (30 s) desorption of U species from swab samples into a stream of 2% (v/v) HNO 3 was possible. The measured 235 U/ 238 U ratios (0.053-1.806) were accurate to within <10%.…”

“…The puried CO 2 was then cryogenically collected in glass ampoules under N 2 and sealed for future offline 14 C measurement. The system was capable of preparing very small samples of 10-50 mg C. The rapid 235 U/ 238 U analyses of material deposited on cotton swabs was possible 30 using an Advion® plate express reader on an Orbitrap® MS instrument equipped with a liquid-sampling GD microplasma ionisation source. Rapid (30 s) desorption of U species from swab samples into a stream of 2% (v/v) HNO 3 was possible.…”