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1.
MC-ICP-MS高精度测定Li同位素分析方法   总被引：6，自引：0，他引：6       下载免费PDF全文
以不同浓度Li元素标准样品和K、Ca、Na、Mg、Fe单元素标准样品的混合溶液为研究对象,采用3根阳离子交换树脂（AG 50W X8,200~400目）填充的聚丙烯交换柱和石英交换柱对Li进行分离富集,淋洗液分别为28 mol/L HCl、015 mol/L HCl以及05 mol/L HCl 30%乙醇,淋洗液体积小,仅为38 mL。分离回收率高,均大于976%。国际标样AGV 2（相对于IRMM 016）、BHVO 2（相对于IRMM 016）和IRMM 016（相对于L SVEC）的δ7Li值分别为(513±094)‰(2σ,n=10)、(408±060)‰(2σ,n=4)和(0038±073)‰(2σ,n=10),与前人分析结果吻合,分析精度与国际同类实验室水平相当。并对比了马里兰大学同位素实验室和笔者实验室对同种岩石矿物样品的分析结果,在误差范围内具有很好的一致性。此外,对美国地质调查局提供的准标样NKT 1霞石岩（相对于IRMM 016）给出了定值,δ7Li值为(871±046)‰(2σ,n=4)。因此,本方法可用于测定天然样品的Li同位素组成。  相似文献   

2.
The accurate and precise determination of Li isotopic composition by MC‐ICP‐MS suffers from the poor performance of traditional column chromatography. Previously established chromatographic processes cannot completely remove Na in complex geological samples, which is currently interpreted to be a result of Na breakthrough. In this study, Na breakthrough during single‐column purification was found to differ between simply artificial Na‐containing sample solutions, where a little Na residue was found, and silicate rocks, where a large amount of breakthrough occurred. A revised two‐step column purification for Li using 0.5 and 0.3 mol l?1 HCl as eluents was designed to remove the Na. This modified method achieves high‐efficiency Li purification from Na and consequently avoiding high Na/Li ratio interference for subsequent MC‐ICP‐MS analyses. The proposed method was validated by the analysis of a series of reference materials, including Li2CO3 (IRMM‐016, ‐0.10‰), basalt (BCR‐2: 2.68‰; BHVO‐2: 4.39‰), andesite (AGV‐2: 6.46‰; RGM‐2: 2.59‰), granodiorite (GSP‐2: ?0.87‰) and seawater (CASS‐5, 30.88‰). This work reports early Na appearance prior to the elution curves in chromatography and emphasises its influence for subsequent Li isotope measurement. Based on the findings, the established two‐step method would be more secure than single‐column chemistry for Li purification.  相似文献   

3.
The demand for large and reliable data sets on isotopic composition has increased in geochemistry and environmental sciences over recent years. We present an automated ion chromatographic separation method using a robotic pipetting arm, termed ‘ChemCobOne’, to reduce sample separation time. Its performance was tested for lithium isotope separation in geological reference materials using a single‐step separation with HCl (0.2 mol l?1) and a 2 ml resin volume. This refined lithium purification method does not forfeit precision, accuracy or purity compared with manual sample processing. In addition, a δ7Li value for NASS‐6 of 30.99 ± 0.50‰ (2s) (95% CI = 0.14‰, n = 44) was determined and the first δ7Li values for the granite rock reference material GS‐N (?0.57 ± 0.25‰ (2s), 95% CI = 0.15‰, n = 15), and for the soil reference material NIST SRM 2709a (?0.37 ± 0.67‰ (2s), 95% CI = 0.15‰, n = 63) are proposed.  相似文献   

4.
A HF‐free sample preparation method was used to purify silicon in twelve geological RMs. Silicon isotope compositions were determined using a Neptune instrument multi‐collector‐ICP‐MS in high‐resolution mode, which allowed separation of the silicon isotope plateaus from their interferences. A 1 μg g‐1 Mg spike was added to each sample and standard solution for online mass bias drift correction. δ30Si and δ29Si values are expressed in per mil (‰), relative to the NIST SRM 8546 (NBS‐28) international isotopic RM. The total variation of δ30Si in the geological reference samples analysed in this study ranged from ‐0.13‰ to ‐0.29‰. Comparison with δ29Si values shows that these isotopic fractionations were mass dependent. IRMM‐17 yielded a δ30Si value of ‐1.41 ± 0.07‰ (2s, n = 12) in agreement with previous data. The long‐term reproducibility for natural samples obtained on BHVO‐2 yielded δ30Si = ‐0.27 ± 0.08‰ (2s, n = 42) on a 12 month time scale. An in‐house Si reference sample was produced to check for the long‐term reproducibility of a mono‐elemental sample solution; this yielded a comparable uncertainty of ± 0.07‰ (2s, n = 24) over 5 months.  相似文献   

5.
We present an open‐source algorithm in Mathematica application (Wolfram Research) with a transparent data reduction and Monte Carlo simulation of systematic and random uncertainties for U‐Th geochronometry by multi‐collector ICP‐MS. Uranium and thorium were quantitatively separated from matrix elements through a single U/TEVA extraction chromatography step. A rigorous calibrator‐sample bracketing routine was adopted using CRM‐112A and IRMM‐035 standard solutions, doped with an IRMM‐3636a 233U/236U ‘double‐spike’ to account for instrumental mass bias and deviations of measured isotope ratios from certified values. The mean of 234U/238U and 230Th/232Th in the standard solutions varied within 0.42 and 0.25‰ (permil) of certified ratios, respectively, and were consistent with literature values within uncertainties. Based on multiple dissolutions with lithium metaborate flux fusion, U and Th concentrations in USGS BCR‐2 CRM were updated to 1739 ± 2 and 5987 ± 50 ng g?1 (95% CI), respectively. The measurement reproducibility of our analytical technique was evaluated by analysing six aliquots of an in‐house reference material, prepared by homogenising a piece of speleothem (CC3A) from Cathedral Cave, Utah, which returned a mean age of 21483 ± 63 years (95% CI, 2.9‰). Replicate analysis of ten samples from CC3A was consistent with ages previously measured at the University of Minnesota by single‐collector ICP‐MS within uncertainties.  相似文献   

6.
The Madi rare metal granite is a complex massif, which contains a variety of rare metals, such as Nb, Ta, Li, and Be. In this paper, the geochemical characteristics of the granite were obtained by multi-collector inductively coupled mass spectrometry (MC-ICP-MS). The precise crystalline age of the granite was obtained from monazite U-Pb dating, and the source of the granite was determined using Li-Nd isotopes. The Madi rare metal granite is a high-K (calc-alkaline), peraluminous, S-type granite. The U-Pb monazite age indicates that the crystalline age of the granite is 175.6 Ma, which is Early Jurassic. The granite is characterized by a relatively wide range of δ7Li values (+2.99‰ to +5.83‰) and high lithium concentrations (181 ppm to 1022 ppm). The lithium isotopic composition of the granite does not significantly correlate with the degree of magmatic differentiation. An insignificant amount of lithium isotope fractionation occurred during the granitic differentiation. The lithium isotopic composition of the granite significantly differs from that of the wall rock, but it is very similar to that of a primitive mantle peridotite xenolith (mean δ7Li value +3.5‰). The plot of Li concentration versus δ7Li indicates that the Li isotopic composition of the granite is similar to that of island arc lavas. Based on the above-described evidence, the granite was mainly derived from the crust, but it was contaminated by a deep granitic magma.  相似文献   

7.
Two large pegmatitic crystals of sodic pyroxene (aegirine) and sodic amphibole (arfvedsonite) from the agpaitic igneous Ilímaussaq Complex, south Greenland were found to be suitable as reference materials for in situ Li isotope determinations. Lithium concentrations determined by SIMS and micro‐drilled material analysed by MC‐ICP‐MS generally agreed within analytical uncertainty. The arfvedsonite crystal was homogeneous with [Li] = 639 ± 51 μg g?1 (2s, n = 69, MC‐ICP‐MS and SIMS results). The aegirine crystal shows strongly developed sector zoning, which is a common feature of aegirines. Using qualitative element mapping techniques (EPMA), the homogeneous core of the crystal was easily distinguished from the outermost sectors of the crystals. The core had a mean [Li] of 47.6 ± 3.6 μg g?1 (2s, n = 33) as determined by SIMS. The seven micro‐drilled regions measured by solution MC‐ICP‐MS returned slightly lower concentrations (41–46 μg g?1), but still overlap with the SIMS data within uncertainty. Based on MC‐ICP‐MS and SIMS analyses, the variation in δ7Li was about 1‰ in each of the two crystals, which is smaller than that in widely used glass reference materials, making these two samples suitable to serve as reference materials. There was, however, a significant offset between the results of MC‐ICP‐MS and SIMS. The latter deviated from the MC‐ICP‐MS results by ?6.0 ± 1.9‰ (2s) for the amphibole and by ?3.9 ± 1.9‰ (2s) for the aegirine. This indicates the presence of a significant matrix effect in SIMS determinations of Li isotopes for amphibole and pyroxene relative to the basalt glasses used for calibration. Based on the MC‐ICP‐MS results, mean δ7Li values of +0.7 ± 1.2‰ (2s, n = 10) for the arfvedsonite crystal and of ?3.7 ± 1.2‰ (2s, n = 7) for the core of the aegirine crystal were calculated. Adopting these values, SIMS users can correct for the specific IMF (instrumental mass fractionation) of the ion probe used. We propose that these two crystals serve as reference materials for in situ Li isotope determinations by SIMS and pieces of these two crystals are available from the first author upon request.  相似文献   

8.
An organic solvent‐free two‐step column procedure is presented that provided robust, high yield and super clean separation of Li from silicate rock sample matrices. The measured δ7Li value for BHVO‐2 of +4.29 ± 0.23‰ (1s) is comparable with the reported values. The δ7Li values for GSJ JP‐1 (+3.14 ± 0.41‰, 1s) and USGS DTS‐2 (+4.91 ± 0.34‰, 1s) presented here provide new reference values for ultramafic rock reference materials.  相似文献   

9.
In this study, the accuracy and the precision corresponding to Li isotopic measurements of low level samples such as marine and coastal carbonates are estimated. To this end, a total of fifty‐four analyses of a Li‐pure reference material (Li7‐N) at concentrations ranging from 1 to 6 ng ml?1 were first performed. The average δ7Li values obtained for solutions with and without chemical purification were 30.3 ± 0.4‰ (2s, n = 19) and 30.2 ± 0.4‰ (2s, n = 36), respectively. These results show that the chosen Li chemical extraction and purification procedure did not induce any significant isotope bias. Two available carbonate reference materials (JCt‐1 and JCp‐1) were analysed, yielding mean δ7Li values of 18.0 ± 0.27‰ (2s, n = 6) and 18.8 ± 1.8‰ (2s, n = 9), respectively. Small powder aliquots (< 15 mg) of JCp‐1 displayed significant isotope heterogeneity and we therefore advise favouring JCt‐1 for interlaboratory comparisons. The second part of this study concerns the determination of δ7Li value for biogenic carbonate samples. We performed a total of twenty‐nine analyses of seven different tropical coral species grown under controlled and similar conditions (24.0 ± 0.1 °C). Our sample treatment prior to Li extraction involved removal of organic matter before complete dissolution in diluted HCl. Our results show (a) a constant δ7Li within each skeleton and between the different species (δ7Li = 17.3 ± 0.7‰), and (b) a Li isotope fractionation of ?2‰ compared with inorganic aragonite grown under similar conditions. Comparison with literature data suggests a significant difference between samples living in aquaria and those grown in natural conditions. Finally, we investigate ancient (fossil) carbonate material and foraminifera extracted from marine sedimentary records. Different leaching procedures were tested using various HCl molarities. Results indicate that carbonate preferential dissolution must be carried out at an acid molarity < 0.18 mol l?1. Possible contamination from silicate minerals can be verified using the Al/Ca ratio, but the threshold value strongly depends on the carbonate δ7Li value. When the silicate/carbonate ratio is high in the sediment sample (typically > 2), contamination from silicates cannot be avoided, even at low HCl molarity (? 0.1 mol l?1). Finally, bulk carbonate and foraminifera extracted from the same core sample exhibited significant discrepancies: δ7Li values of foraminifera were more reproducible but were significantly lower. They were also associated with lower Sr/Ca and higher Mn/Ca ratios, suggesting a higher sensitivity to diagenesis, although specific vital effects cannot be fully ruled out.  相似文献   

10.
In this article, we document a detailed analytical characterisation of zircon M127, a homogeneous 12.7 carat gemstone from Ratnapura, Sri Lanka. Zircon M127 has TIMS‐determined mean U–Pb radiogenic isotopic ratios of 0.084743 ± 0.000027 for 206Pb/238U and 0.67676 ± 0.00023 for 207Pb/235U (weighted means, 2s uncertainties). Its 206Pb/238U age of 524.36 ± 0.16 Ma (95% confidence uncertainty) is concordant within the uncertainties of decay constants. The δ18O value (determined by laser fluorination) is 8.26 ± 0.06‰ VSMOW (2s), and the mean 176Hf/177Hf ratio (determined by solution ICP‐MS) is 0.282396 ± 0.000004 (2s). The SIMS‐determined δ7Li value is ?0.6 ± 0.9‰ (2s), with a mean mass fraction of 1.0 ± 0.1 μg g?1 Li (2s). Zircon M127 contains ~ 923 μg g?1 U. The moderate degree of radiation damage corresponds well with the time‐integrated self‐irradiation dose of 1.82 × 1018 alpha events per gram. This observation, and the (U–Th)/He age of 426 ± 7 Ma (2s), which is typical of unheated Sri Lankan zircon, enable us to exclude any thermal treatment. Zircon M127 is proposed as a reference material for the determination of zircon U–Pb ages by means of SIMS in combination with hafnium and stable isotope (oxygen and potentially also lithium) determination.  相似文献   

11.
Three tourmaline reference materials sourced from the Harvard Mineralogical and Geological Museum (schorl 112566, dravite 108796 and elbaite 98144), which are already widely used for the calibration of in situ boron isotope measurements, are characterised here for their oxygen and lithium isotope compositions. Homogeneity tests by secondary ion mass spectrometry (SIMS) showed that at sub‐nanogram test portion masses, their 18O/16O and 7Li/6Li isotope ratios are constant within ± 0.27‰ and ± 2.2‰ (1s), respectively. The lithium mass fractions of the three materials vary over three orders of magnitude. SIMS homogeneity tests showed variations in 7Li/28Si between 8% and 14% (1s), which provides a measure of the heterogeneity of the Li contents in these three materials. Here, we provide recommended values for δ18O, Δ’17O and δ7Li for the three Harvard tourmaline reference materials based on results from bulk mineral analyses from multiple, independent laboratories using laser‐ and stepwise fluorination gas mass spectrometry (for O), and solution multi‐collector inductively coupled plasma‐mass spectroscopy (for Li). These bulk data also allow us to assess the degree of inter‐laboratory bias that might be present in such data sets. This work also re‐evaluates the major element chemical composition of the materials by electron probe microanalysis and investigates these presence of a chemical matrix effect on SIMS instrumental mass fractionation with regard to δ18O determinations, which was found to be < 1.6‰ between these three materials. The final table presented here provides a summary of the isotope ratio values that we have determined for these three materials. Depending on their starting mass, either 128 or 512 splits have been produced of each material, assuring their availability for many years into the future.  相似文献   

12.
Isotope ratios of heavy elements vary on the 1/10000 level in high temperature materials, providing a fingerprint of the processes behind their origin. Ensuring that the measured isotope ratio is precise and accurate depends on employing an efficient chemical purification technique and optimised analytical protocols. Exploiting the disparate speciation of Cu, Fe and Zn in HCl and HNO3, an anion exchange chromatography procedure using AG1‐×8 (200–400 mesh) and 0.4 × 7 cm Teflon columns was developed to separate them from each other and matrix elements in felsic rocks, basalts, peridotites and meteorites. It required only one pass through the resin to produce a quantitative and pure isolate, minimising preparation time, reagent consumption and total analytical blanks. A ThermoFinnigan Neptune Plus MC‐ICP‐MS with calibrator‐sample bracketing and an external element spike was used to correct for mass bias. Nickel was the external element in Cu and Fe measurements, while Cu corrected Zn isotopes. These corrections were made assuming that the mass bias for the spike and analyte element was identical, and it is shown that this did not introduce any artificial bias. Measurement reproducibilities were ± 0.03‰, ± 0.04‰ and ± 0.06‰ (2s) for δ57Fe, δ65Cu and δ66Zn, respectively.  相似文献   

13.
A new natural zircon reference material SA01 is introduced for U‐Pb geochronology as well as O and Hf isotope geochemistry by microbeam techniques. The zircon megacryst is homogeneous with respect to U‐Pb, O and Hf isotopes based on a large number of measurements by laser ablation‐inductively coupled plasma‐mass spectrometry (LA‐ICP‐MS) and secondary ion mass spectrometry (SIMS). Chemical abrasion isotope dilution thermal ionisation mass spectrometry (CA‐ID‐TIMS) U‐Pb isotopic analyses produced a mean 206Pb/238U age of 535.08 ± 0.32 Ma (2s, n = 10). Results of SIMS and LA‐ICP‐MS analyses on individual shards are consistent with the TIMS ages within uncertainty. The δ18O value determined by laser fluorination is 6.16 ± 0.26‰ (2s, n = 14), and the mean 176Hf/177Hf ratio determined by solution MC‐ICP‐MS is 0.282293 ± 0.000007 (2s, n = 30), which are in good agreement with the statistical mean of microbeam analyses. The megacryst is characterised by significant localised variations in Th/U ratio (0.328–4.269) and Li isotopic ratio (?5.5 to +7.9‰); the latter makes it unsuitable as a lithium isotope reference material.  相似文献   

14.
The commonly used, but no longer available, reference materials NIST SRM 976 (Cu) and ‘JMC Lyon’ (Zn) were calibrated against the new reference materials ERM®‐AE633, ERM®‐AE647 (Cu) and IRMM‐3702 (Zn), certified for isotope amount ratios. This cross‐calibration of new with old reference materials provides a continuous and reliable comparability of already published with future Cu and Zn isotope data. The Cu isotope amount ratio of NIST SRM 976 yielded δ65/63Cu values of ?0.01 ± 0.05‰ and ?0.21 ± 0.05‰ relative to ERM®‐AE633 and ERM®‐AE647, respectively, and a δ66/64ZnIRMM‐3702 value of ?0.29 ± 0.05‰ was determined for ‘JMC Lyon’. Furthermore, we separated Cu and Zn from five geological reference materials (BCR‐2, BHVO‐2, BIR‐1, AGV‐1 and G‐2) using a two‐step ion‐exchange chromatographic procedure. Possible isotope fractionation of Cu during chromatographic purification and introduction of resin‐ and/or matrix‐induced interferences were assessed by enriched 65Cu isotope addition. Instrumental mass bias correction for the isotope ratio determinations by MC‐ICP‐MS was performed using calibrator‐sample bracketing with internal Ni doping for Cu and a double spike approach for Zn. Our results for the five geological reference materials were in very good agreement with literature data, confirming the accuracy and applicability of our analytical protocol.  相似文献   

15.
Six tourmaline samples were investigated as potential reference materials (RMs) for boron isotope measurement by secondary ion mass spectrometry (SIMS). The tourmaline samples are chemically homogeneous and cover a compositional range of tourmaline supergroup minerals (primarily Fe, Mg and Li end‐members). Additionally, they have homogeneous boron delta values with intermediate precision values during SIMS analyses of less than 0.6‰ (2s). These samples were compared with four established tourmaline RMs, that is, schorl IAEA‐B‐4 and three Harvard tourmalines (schorl HS#112566, dravite HS#108796 and elbaite HS#98144). They were re‐evaluated for their major element and boron delta values using the same measurement procedure as the new tourmaline samples investigated. A discrepancy of about 1.5‰ in δ11B was found between the previously published reference values for established RMs and the values determined in this study. Significant instrumental mass fractionation (IMF) of up to 8‰ in δ11B was observed for schorl–dravite–elbaite solid solutions during SIMS analysis. Using the new reference values determined in this study, the IMF of the ten tourmaline samples can be modelled by a linear combination of the chemical parameters FeO + MnO, SiO2 and F. The new tourmaline RMs, together with the four established RMs, extend the boron isotope analysis of tourmaline towards the Mg‐ and Al‐rich compositional range. Consequently, the in situ boron isotope ratio of many natural tourmalines can now be determined with an uncertainty of less than 0.8‰ (2s).  相似文献   

16.
Lithium (Li) is a fluid-mobile element and δ7Li in secondary deposits represents an excellent proxy for silicate weathering and authigenic mineral formation. The soil samples from 1205 to 1295 cm in the Weinan profile, one of the best developed loess-paleosol sequences covering the last glacial–interglacial climatic cycle, were collected and chemically separated into detritus and carbonate fractions for subsequent analyses of Li, δ7Li, major and trace elements. Other desert specimens (i.e., Qaidam Desert, Tengger Desert, Badain Juran Desert and Taklimakan Desert) near the Chinese Loess Plateau (CLP) and various standard clays were analyzed for assisting provenance determination. The Li and δ7Li distributions in the detritus are rather homogeneous, 1.4–2.0 μg/g and +2.5‰ to +4.7‰, respectively, compared with the carbonate fraction. The detrital δ7Li varies systematically with magnetic susceptibility and grain size changes, reflecting significant Li isotopic variation associated with sources and mineralogy of detrital material. On the other hand, Li and δ7Li in carbonates show large changes, 781–963 ng/g and −4.1‰ to +10.2‰, respectively. These carbonate δ7Li correlated well with the estimated index of chemical weathering, as a result of Li mobilization and soil formation during chemical weathering.  相似文献   

17.
In this study, a technique for high precision in situ Fe and Mg isotope determinations by femtosecond‐laser ablation‐multi collector‐ICP‐MS (fs‐LA‐MC‐ICP‐MS) was developed. This technique was employed to determine reference values for a series of common reference glasses that may be used for external standardisation of in situ Fe and Mg isotope determinations in silicates. The analysed glasses are part of the MPI‐DING and United States Geological Survey (USGS) reference glass series, consisting of basaltic (BIR‐1G, BCR‐2G, BHVO‐2G, KL2‐G, ML3B‐G) and komatiitic (GOR128‐G and GOR132‐G) compositions. Their Fe and Mg isotope compositions were determined by in situ fs‐LA‐MC‐ICP‐MS and by conventional solution nebulisation multi‐collector ICP‐MS. We determined δ56Fe values for these glasses ranging between ‐0.04‰ and 0.10‰ (relative to IRMM‐014) and δ26Mg values ranging between ‐0.40‰ and ‐0.15‰ (relative to DSM‐3). Our fs‐LA‐MC‐ICP‐MS results for both Fe and Mg isotope compositions agreed with solution nebulisation analyses within analytical uncertainties. Furthermore, the results of three USGS reference glasses (BIR‐1G, BHVO‐2G and BCR‐2G) agreed with previous results for powdered and dissolved aliquots of the same reference materials. Measurement reproducibilities of the in situ determinations of δ56Fe and δ26Mg values were usually better than 0.12‰ and 0.13‰ (2s), respectively. We further demonstrate that our technique is a suitable tool to resolve isotopic zoning in chemically‐zoned olivine crystals. It may be used for a variety of different applications on isotopically‐zoned minerals, e.g., in magmatic or metamorphic rocks or meteorites, to unravel their formation or cooling rates.  相似文献   

18.
We report here a newly developed method for measurement of Li isotopes by use of multi-collector ICP-MS (Neptune) allowing rapid and high precision determination of Li isotope ratios at low levels of lithium (15–20 ng). The lithium reference sample solution IRMM-016 was analysed over a period of ten months with an external reproducibility of 0.24% (2s, n = 52). Chemical separation of Li from matrix was performed on the seawater sample IRMM BCR-403, for which a mean δ7Li value of + 31.0 ± 0.1 % (2s/√n, n = 31) was obtained. This mean value is in good agreement with those previously published for other seawater samples. BCR-403 seawater being readily available, we propose that this seawater sample be used as a reference sample for Li isotope measurements.  相似文献   

19.
锂同位素及其地质应用研究进展   总被引：7，自引：0，他引：7  
锂同位素示踪是近几年发展起来的一门新兴的稳定同位素地球化学方法,锂有两个稳定同位素：^6Li和^7Li。自在界锂同位素的组成变化很大,其δ^6Li值变化幅度超过60‰,现代大洋水的δ^6Li值为－31．0‰,洋中脊玄武岩（BORB）的δ^6Li值为－4．7‰--3.7‰,由于锂同位素存在大的分馏和不同地质体中在截然不同的δ^6Li值,因此锂同位素地质应用前景十分广泛。目前,锂同位素在研究星云形成过程和宇宙事件,洋壳蚀变和海底热液活动,壳－幔物质循环和板块俯冲作用过程,判断卤水起源和演化等方面的研究中成效显著。  相似文献   

20.
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.  相似文献   

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