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Cu isotope fractionation was investigated in the human neuroblastoma SH-SY5Y cell line, in a proliferating/tumor phase (undifferentiated cells), and in a differentiated state (neuron-like cells), induced using retinoic acid (RA). The SH-SY5Y cell line displays genetic aberrations due to its cancerous origin, but differentiation drives the cell line towards phenotypes suitable for the research of neurological diseases (e.g., Alzheimer's disease or Parkinson's disease). Cellular Cu distribution was first explored by laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) imaging and, subsequently, Cu isotopic analysis was performed at cellular and sub-cellular levels via multi-collector inductively coupled plasma-mass spectrometry (MC-ICP-MS). The SH-SY5Y cells showed a re-distribution of intracellular Cu upon RA differentiation. Both undifferentiated and differentiated cells became systematically enriched in the light 63Cu isotope with increasing intracellular Cu content. Differentiated neuron-like SH-SY5Y cells showed a heavier Cu isotopic composition (+ 0.3‰) than did the undifferentiated proliferating cells when exposed to Cu for 24 h. However, after a longer exposure time (72 h), no difference was observed between both cellular phenotypes. Mitochondrial fractions were enriched in the light 63Cu isotope, compared to whole cells, for both undifferentiated and differentiated cells (no significant difference). The Cu isotopic composition of the remaining cell lysates was heavier than that of the whole cells and + 0.2‰ heavier in the differentiated cells than in the undifferentiated cells. These results indicate that neuronal differentiation affects the Cu isotope fractionation accompanying Cu uptake in the cells, but this effect does not seem to be associated with the mitochondrial Cu pathway. Cu isotope fractionation can be an interesting tool for studying Cu metabolism at a (sub)-cellular level in functional neurons. [ABSTRACT FROM AUTHOR]

This paper presents a new non-destructive sampling method for the lead isotope analysis of lead objects using acidified cotton swabs. The results are indistinguishable within error margin from conventional sampling methods. This method was applied to a series of Sasanian lead coins from the Royal Museums of Art and History as well as a private collection. Elemental analysis was performed using micro-X-ray fluorescence. Isotopic analysis was performed using multi collector-inductively coupled plasma-mass spectrometry. Lead isotope analysis showed that at least four distinct sources of lead were used over time by the Sasanians to produce coins. Elemental analysis revealed three compositional groups distinct from the isotope groups, showing that a change in composition did not necessarily follow a change in raw materials supply. The uniformity of isotope compositions within particular periods, and of chemical composition across different mints, may point to a central control of both raw material supply and composition of Sasanian lead coins. [ABSTRACT FROM AUTHOR]

A procedure for the measurement of high precision Ca isotope ratios for calcium carbonate samples by multiple collector inductively coupled plasma mass spectrometry (MC-ICP-MS) is reported. Under instrumental low mass resolution mode, 42Ca, 43Ca and 44Ca were measured directly without column chemistry and the measurement uncertainty was 0.08‰ (2sd, n = 32). The background interference on mass 42 u was investigated and minimized to an acceptable level by tuning the sweep gas and ICP torch position. In order to ensure the reliability of the method and quantify the tolerance of samples with incorporated Sr, the effect of Sr as an interference was evaluated for different concentrations, results showing no statistical difference with Sr/Ca <0.1, implying that most natural carbonate materials are accessible by this method. To validate the accuracy of this method, several stalagmite samples were analyzed in a comparative study in the Isotope Geochemistry Laboratory, Department of Earth Sciences, Oxford University. Results from both laboratories are in good statistical agreement which supports the use of this method as a simple, practical approach for Ca isotope measurement of calcium carbonate samples. Unlabelled Image • A simple and reliable method for Ca isotopic analysis of calcium carbonate samples by MC-ICP-MS is presented; • The interference from 40Ar1H 2 + and Sr2+ was effectively reduced/corrected by using some practical skills; • The stalagmite and coral samples could be measured successfully without chemical purification by our method. [ABSTRACT FROM AUTHOR]

Abstract The analysis of environmental swipe samples for ultra-trace uranium (U) and plutonium (Pu) determinations is essential in the nuclear safeguards community. While mass spectrometry techniques for U and Pu detection continually improve, established separation methods are seldom reevaluated. Currently, actinide separations within the forensics community predominantly employ either Eichrom TEVA® or UTEVA® resins. The direct optimization of U and Pu separations utilizing both resins has not been widely reported. Here, several methods were explored with goals of increasing analyte recovery, acquiring cleaner blanks, and improving the separation efficiency of ultra-trace levels of U and Pu from environmental swipe samples. The optimized separation methodology of U and Pu was examined using certified reference materials and archived environmental swipe samples. Graphical abstract fx1 Highlights • Greater than 98% recovery of U and Pu from TEVA and UTEVA cartridges. • Lower U and Pu process blank levels. • Improved separation of ultra-trace (fg-ng) U and Pu from environmental swipe samples. • Faster separation times with reduced reagent usa. [ABSTRACT FROM AUTHOR]

This study presents a high‐precision method to measure barium (Ba) isotope compositions of international carbonate reference materials and natural carbonates. Barium was purified using chromatographic columns filled with cation exchange resin (AG50W‐X12, 200–400 mesh). Barium isotopes were measured by MC‐ICP‐MS, using a 135Ba–136Ba double‐spike to correct mass‐dependent fractionation during purification and instrumental measurement. The precision and accuracy were monitored by measuring Ba isotope compositions of the reference material JCp‐1 (coral) and a synthetic solution obtained by mixing NIST SRM 3104a with other matrix elements. The mean δ137/134Ba values of JCp‐1 and the synthetic solution relative to NIST SRM 3104a were 0.21 ± 0.03‰ (2s, n = 16) and 0.02 ± 0.03‰ (2s, n = 6), respectively. Replicate measurements of NIST SRM 915b, COQ‐1, natural coral and stalagmite samples gave average δ137/134Ba values of 0.10 ± 0.04‰ (2s, n = 18), 0.08 ± 0.04‰ (2s, n = 20), 0.27 ± 0.04‰ (2s, n = 16) and 0.04 ± 0.03‰ (2s, n = 20), respectively. Barium mass fractions and Ba isotopes of subsamples drilled from one stalagmite profile were also measured. Although Ba mass fractions varied significantly along the profile, Ba isotope signatures were homogeneous, indicating that Ba isotope compositions of stalagmites could be a potential tool (in addition to Ba mass fractions) to constrain the source of Ba in carbonate rocks and minerals. [ABSTRACT FROM AUTHOR]

The lithium isotope system can be an important tracer for various geological processes, especially tracing continental weathering. The key to this application is the accurate and precise determination of lithium isotopic composition. However, some of the previously established column separation methods are not well behaved when applied to chemically diverse materials, due to the significant variations in matrix/lithium ratios in some materials. Here, we report a new dual‐column system for lithium purification to achieve accurate and precise analysis of lithium isotopic compositions using a multi‐collector inductively coupled plasma‐mass spectrometer (MC‐ICP‐MS). Compared with single‐column systems, our dual‐column system yielded a consistent elution range of the lithium‐bearing fraction (7–16 ml) for samples with a large range of lithium loads and matrix compositions, so that column re‐calibration is not required. In addition, this method achieved complete lithium recovery and low matrix interference (e.g., Na/Li ≤ 1) with a short elution time (~ 6 h, excluding evaporation), with the entire procedure completed in 1.5 days. We report high precision Li isotopic compositions in twelve chemically diverse materials including seawater, silicates, carbonates, manganese nodules and clays. New recommended Li isotopic values and associated uncertainties are presented as reference values for quality control and inter‐laboratory calibration for future research and were consistent with previously published data. However, significant lithium isotopic variances (~ 1‰) in BHVO‐2 from different batches suggest Li isotopic heterogeneity in this reference material and that Li isotopic studies using this reference material should be treated with caution. [ABSTRACT FROM AUTHOR]

Geographical traceability of marine bivalves is critical to guarantee their quality and safeguard the interest of both consumers and producers. The neodymium isotopic ratio (143Nd/144Nd) of the coastal water mainly reflects the geology of its neighboring watershed, displaying the distinct and systematic variability at high level of geographical detail and thereby shedding light on its potential as a geochemical tracer. For the first time, the present study investigated the utility and robustness of 143Nd/144Nd archived in mytilid mussel shells for geographical traceability purposes. The reproducibility of 143Nd/144Nd ratios maintained in mussels shells from the same cohort demonstrates that the Nd isotopic ratio meets the major requirement for an ideal geochemical tracer, i.e., the biologically induced variation should be rather minimal. The distribution and variability of mussel shell 143Nd/144Nd patterns were subsequently mapped along the Japanese and Chinese coastal waters. Neodymium isotopes of mussel shells record 143Nd/144Nd variations among local regions and between the two countries, which are rather compatible with the ages and lithology of the continental bedrocks. These findings highlight the great potential of 143Nd/144Nd for tracing the geographical origin of marine bivalves. • Consistency of 143Nd/144Nd ratios maintained in contemporaneous mussel shells. • 143Nd/144Nd ratios of mussel shells reflects the geology of coastal watershed. • Mussel shell 143Nd/144Nd patterns mapped in Japan and China. • 143Nd/144Nd ratio serves as a promising tracer for molluscan traceability. [ABSTRACT FROM AUTHOR]

This contribution describes methods for measuring Eu isotopic ratios in geological materials using multi-collector inductively coupled plasma mass spectrometer. These methods require an initial external correction of mass discrimination effects (between the two Eu isotopes) using a Sm isotopic spike (150Sm/154Sm = 0.3244) added to samples. Eu was then estimated according to an exponential law. We measured Eu isotope ratios (151Eu/153Eu) for six high-purity commercial Eu reagents using the NIST 3117a standard as a reference (δ151/153Eu = 0.0‰). The Eu reagents showed minor fractionation effects ranging from 0.029 ± 0.007‰ (1σ, n = 22) to 0.061 ± 0.006‰ (1σ, n = 13). We then investigated Eu isotope fractionation during cation exchange chromatography, which efficiently separates the Eu fraction (>99.99% purity). A known amount of rare earth element (REE) standard solution was eluted from columns using 2-hydroxyisobutyric acid. Fourteen sequentially collected Eu fractions gave δ151/153Eu values ranging from −1.80‰ for early eluting fractions to 2.56‰ for late eluting fractions. A numerically integrated value for the 14 fractions resembled that measured for the total eluted solution. These results indicate that different reagents give different Eu isotopic values. Fractionation may occur during reagent production or it may be inherited from geological source materials. We also measured Eu isotopic variation among five different geochemical reference rocks (BCR2, BHVO2, BIR1a, GSP2, JG1a). The reference standards also gave slightly different 151/153Eu isotope ratios. These results suggest Eu isotopic fractionation during rock-forming processes. Unlabelled Image • Eu isotopic compositions were measured from pure commercial chemical reagents. • An experimental procedure for high purity Eu separation was proposed. • A method to measure and correct mass bias for the two Eu isotopes using MC-ICP-MS was proposed. • Evidence of Eu isotopic fractionation in natural systems was observed. [ABSTRACT FROM AUTHOR]

High-latitude cold-water coral reefs are particularly vulnerable to climate change due to enhanced CO 2 uptake in these regions. To evaluate their physiological functioning and potential application as pH archives, we retrieved both recent and fossil samples of Lophelia pertusa along the Norwegian margin from Oslofjord (59°N), over to Trondheimsfjord, Sula and Lopphavet (70.6°N). Boron isotope analyses (δ11B) were undertaken using solution-based and laser ablation multi-collector inductively coupled plasma mass spectrometry (MC-ICP-MS; LA-ICP-MS), and secondary ion mass spectrometry (SIMS). Epi-fluorescence microscopy was employed to provide a rapid pre-screening routine for structure-specific subsampling in the coral skeleton. This integrated approach enabled us to assess heterogeneities within single specimens, as well as to investigate the role of local environmental influences including recent and past variations. All three mass spectrometry methods show substantial differences in the δ11B of the theca wall (TW) and the centres of calcification (COC's). Micro-bulk subsamples milled from the theca wall of modern specimens originating from different habitats but with comparable seawater pH (8–8.16) gave consistent δ11B values averaging 26.7 (±0.2‰, 2σ, n = 4), while COC subsamples systematically deviated towards lower B/Ca (by ~40%) and depleted δ11B values (minimum 22.7 ± 0.3‰, 2σ), implying a difference of at least 4‰ between TW and COC. SIMS and LA-ICP-MS measurements identified much larger internal heterogeneities with maximum variation of ~10‰ between the distinct skeletal structures; minimal SIMS δ11B values of ~17.3 ± 1.2‰ (2σ) were associated with the pure COC material. Our findings may be interpreted in terms of the occurrence of two main, but likely different, biomineralisation mechanisms in L. pertusa , with the COC's generally exhibiting minimal pH up-regulation, potentially supporting the use of bicarbonate in the early stages of biomineralisation. Furthermore, we highlight the potential utility of L. pertusa for palaeo-proxy studies if targeting the compositionally homogenous TW zones devoid of COC admixtures, which appear to provide highly reproducible measurements. [ABSTRACT FROM AUTHOR]

Graphical abstract Highlights • MC-ICP-MS and INAA proved equivalent in measuring the 58Fe/54Fe ratio. • The uncertainties in INAA are substantially higher than those in MC-ICP-MS. • INAA offers a high specificity and selectivity for iron close to 100%. • The preparative steps before measurement are simpler in INAA than in MC-ICP-MS. • The costs of measuring iron isotopes with the two techniques are comparable. Abstract As a safer alternative for the use of radioactive tracers, the enriched stable 58Fe isotope has been introduced in studies of iron metabolism. In this study this isotope is measured with instrumental neutron activation analysis (INAA) in blood samples of patients with iron related disorders and controls after oral ingestion of a 58Fe containing pharmaceutical. Results were compared with those derived from MC-ICP-MS, applied on the same samples, and analytical and practical aspects of the two techniques were compared. Both techniques showed an increased absorption and incorporation in red blood cells of the 58Fe isotope in iron deficient patients in contrast to the controls. In all individuals results of INAA measurements were in good agreement with those of MC-ICP-MS (|zeta| < 2). Uncertainties in INAA are substantially higher than those achievable by MC-ICP-MS but the INAA technique offers a high specificity and selectivity for iron close to 100%. In contrast to INAA, sample preparation before measurement is very critical in MC-ICP-MS and interferences with 58Ni and 54Cr may hamper the measurement of 58Fe and 54Fe respectively. Since it takes at least five days after irradiation to reduce the activity of interfering radionuclides (mainly 24Na), INAA is a more time consuming procedure; the need of a nuclear reactor facility makes it also less accessible than MC-ICP-MS. Costs are comparable. Both INAA and MC-ICP-MS are able to adequately measure changes in iron isotope composition in blood when an enriched stable iron isotope is applied in clinical research. Although MC-ICP-MS is more sensitive, is faster and has easier access, in INAA preparative steps before measurement are simpler and there are hardly demands on the kind and size of the samples. This may be relevant working with biomaterials in a clinical setting. [ABSTRACT FROM AUTHOR]

Abstract Moderately volatile elements show variable depletion in terrestrial planets compared to the Sun. Isotopic ratios can be used as a signature of the processes at the origin of this depletion. Using a new method, the Sn stable isotope composition and elemental abundance in 36 primitive meteorites (chondrites) have been characterised to high precision. Significant mass-dependent Sn isotope variations are found within chondrites. The widest isotopic range is observed for the ordinary chondrites (−1.1 ‰ to +0.5 ‰ in δ122/118Sn, representing the difference in the 122Sn/118Sn ratio of the sample relative to our in-house standard, Sn_IPGP), with the ordinary chondrite groups extending to lighter isotopic compositions in the order H > L > LL, while carbonaceous and enstatite chondrites are heavier and occupy narrower compositional ranges. Tin and Zn isotope and concentration data are strongly correlated, particularly in ordinary chondrites, from which both sets of data were obtained on the same rock powders. Given the difference in geochemical behaviour (Zn lithophile/chalcophile and Sn chalcophile/siderophile) of these elements, this suggests that the primary control on the isotope and abundance variations is volatility. Chondrite groups show variability increasing with petrographic types, suggesting a secondary control from parent-body metamorphism. The isotopic composition of the bulk silicate Earth (BSE; δ 122/118Sn = 0.49 ± 0.11 ‰) overlaps with the carbonaceous chondrites (δ 122/118Sn = 0.43 ± 0.12 ‰ ; excl. CR and CK). Despite isotopic similarities for almost all isotopic systems, EH chondrites have Sn isotope compositions that are distinct from the bulk silicate Earth (δ 122/118Sn = 0.18 ± 0.21 ‰). Therefore, an enstatite chondrite-like bulk Earth requires that isotopically light Sn was lost from the silicate Earth, possibly into the metallic core or a sulphide matte, or by evaporative loss from Earth or its precursors. Highlights • First characterisation of Sn isotope variations in all groups of chondrites • Significant (>0.5 ‰ per amu) mass-dependent Sn isotope variations amongst chondrite meteorite samples • No correlation with metamorphic grade or degree of aqueous alteration • Strong correlations with other moderately volatile elements, suggesting isotope variations controlled by volatility • Constrains the origins of volatile element depletions in planetary materials and the nature of Earths building blocks [ABSTRACT FROM AUTHOR]

Abstract Radiogenic and stable isotopic tracing of crude oils has not so far been undertaken, largely because of the difficulties of dealing with the low trace element contents of oil samples for high-precision isotopic measurements. Here, we present a novel analytical protocol that allows for precise and accurate determination of radiogenic Pb and stable Zn isotopic compositions on as little as 5 ml of crude oil from a variety of geographically, geologically, and environmentally diverse settings. The 41 Pb and Zn samples measured to validate the new protocol were separated from their respective crude oils by liquid-liquid extraction into an aqueous phase readily handled in a clean laboratory for subsequent purification of Pb and Zn by standard anion-exchange column chromatography. Lead and Zn isotopic compositions on the same 5 ml sample of crude oil were obtained by MC-ICP-MS on 95% of the total extracted Pb and Zn, while elemental concentrations were measured by Q-ICP-MS on 5% aliquots. To the best of our knowledge, the present technique is the first efficient procedure for Pb and Zn isotopic analysis of crude oil, which, owing to the elimination of the organic fraction at the liquid-liquid extraction stage, does not require any specialized equipment, neither for the wet chemistry nor for the mass spectrometry. The high extraction yields of the method and the low detection limits and high sensitivity of, respectively, Q-ICP-MS and MC-ICP-MS permit analysis of very small sample quantities (down to 2 ng and 100 ng, respectively, of Pb and Zn for isotopic analysis, and a few hundred pg for abundance measurements). Reproducibility is on a par with routine state-of-the-art Pb and Zn isotopic measurements of other types of geological materials, while total procedural blanks for both elements are negligible relative to the amounts of Pb and Zn typically separated from crude oil. [ABSTRACT FROM AUTHOR]

The determination of boron isotopes (δ11B) represents a powerful tool for a variety of applications such as the reconstruction of past ocean pH and atmospheric p CO 2 from the analysis of marine biogenic carbonates. In recent years, MC-ICP-MS has gained popularity over other techniques thanks to its superior sample throughput and high ionization efficiency. This study evaluates, for the first time, the performance of the Nu Instruments Plasma 3 MC-ICP-MS for measuring δ11B using different sample introduction systems and detector configurations. The main goal is to provide a detailed methodology for nanogram-scale boron isotope analysis through a straightforward approach that can be easily adopted. Boron (B) purification from the carbonate matrix was performed through micro-distillation, using a temperature of 95 °C and a minimum heating duration of 15 h, allowing the full recovery of B from up to 3 mg of carbonate mass. We attained blank values (on average 14 ± 6 pg, 1 SD, n = 27) comparable to the lowest micro-distillation blanks reported in the literature. Three sample introduction systems were tested, and the 30 μL min−1 nebuliser system outperformed the 50 and 170 μL min−1 systems in terms of signal intensity per mass of B. Two detector configurations were used based on the total boron signal intensity achieved: (1) FC11/FC12, with two Faraday cups fitted to 1011 Ω and 1012 Ω amplifier resistors to detect 11B and 10B ion beams, respectively, and (2) FC12/IC, with which we investigated, for the first time, the feasibility of combining an ion counter for detecting 10B, and a Faraday cup fitted to a 1012 Ω amplifier for 11B. The FC12/IC configuration provided accurate results compared to the use of two Faraday cups for total boron signals lower than 0.35 V (∼12 ng of B in the analysed solution). The proposed analytical procedure was validated through the analysis of several reference materials with varying boron amounts, including clam JCt-1, coral JCp-1, NIST RM 8301 Foram and Coral solutions, and boric acid ERM-AE121. Furthermore, the long-term reproducibility was assessed with two in-house standards (coral CLD-1 and foraminifera GINF-1), providing values of 25.68 ± 0.23 ‰ (2SD, n = 53; with 14–36 ng of B) and 14.90 ± 0.16 ‰ (2SD, n = 12; with 11–16 ng of B), respectively. [Display omitted] • First assessment of Nu Plasma 3 MC-ICP-MS performance for δ11B analysis. • A detailed and straightforward approach for nanogram-scale δ11B analysis is provided. • Combining Faraday cup and ion counter detectors enables feasible δ11B measurements. • Microsublimation at 95 °C for ≥15 h allows boron recovery of up to 3 mg of CaCO 3. • A systematic evaluation of factors determining δ11B uncertainty is presented. [ABSTRACT FROM AUTHOR]

[Display omitted] • Different signals of boron isotope are explored in natural soil profiles vertically. • The isotopic compositions of different boron speciation in soils are investigated. • The δ11B distributions of AB and TB are influenced by physicochemical processes. • Higher δ11B in topsoil show B isotope fractionation in soil–plant–soil processes. Available boron (AB) and total boron (TB) in soil have distinct isotopic values, which are mainly influenced by the pH, organic matter and clay minerals, and can be used to explore the chemical behaviors of boron (B) in adsorption, weathering and eluviation processes. The B isotopic compositions of AB and TB in brown soil (slightly acidic) and cinnamon soil (neutral to slightly alkaline) profiles were investigated by multicollector inductively coupled plasma mass spectrometry. Variations in pH value and organic matter in the two soils directly affected the adsorption of B isotopes (dissolved 11B(OH) 3 or 10B(OH) 4 -) in the aqueous solution, as shown by AB having an average negative δ11B value of −1‰ and a great range of −10.83‰ to +8.32‰ in the cinnamon soil. Furthermore, the long-term effects of adsorption and transportation processes were evidenced by the large range of δ11B TB values (-24.22‰ to +21.07‰) in the two soils. The topsoil layers with more organic matter and higher δ11B values indicated that B isotope fractionation occurred as a result of the input of rainfall, recycling of plant litter and the adsorption of organic matter and clay minerals. The lower δ11B values, the higher B contents and the element ratios in the underlying layers resulted from the weathering of different minerals and the adsorption of AB in the leaching process. This finding is supported by the relationship between AB and the clay/silt ratio, with more negative δ11B values being associated with finer clay particles via the adsorption of 10B(OH) 4 - in a weakly alkaline soil solution. The δ11B values in soils may be a useful tool for distinguishing geochemical cycling and processes and characterizing long-term processes that are difficult to assess. [ABSTRACT FROM AUTHOR]

A new chemical separation has been developed to isolate uranium (U) using two UTEVA columns to minimize iron and thorium interferences from high background area soil samples containing minerals like monazites and ilmenite. The separation method was successfully verified in some certified reference materials (CRMs), for example, JSd-2, JLk-1, JB-1 and JB-3. The same method was applied for purification of U in Fukushima soil samples affected by the Fukushima dai-ichi nuclear power station (FDNPS) accident. Precise and accurate measurement of 234U/238U and 235U/238U isotope ratios in chemically separated U were carried out using a multi-collector inductively coupled plasma mass spectrometer (MC-ICP-MS). In this mass spectrometric method, an array of two Faraday cups (1011 Ω, 1012 Ω resistor) and a Daly detector were simultaneously employed. The precision of U isotope ratios in an in-house standard was evaluated by replicate measurement. Relative standard deviation (RSD) of 234U/238U and 235U/238U were found to be 0.094% (2σ) and 0.590% (2σ), respectively. This method has been validated using a standard reference material SRM 4350B, sediment sample. The replicate measurements of 234U/238U in SRM shows 0.7% (RSD). This developed method is suitable for separation of U and its isotope ratio measurement in environmental samples.

Precise tellurium (Te) isotope ratio measurement using mass spectrometry is a challenging task for many decades. In this paper, Te isotope ratio measurements using multi-collector inductively coupled plasma mass spectrometry (MC–ICP–MS) in terrestrial Te standards have been reported. Newly developed Faraday cup with 1012 Ω resistor is used to measure low abundance 120Te, whereas the 1011 Ω resistor is used to measure other Te isotopes. The relative standard deviation obtained for Te isotope ratio measurement by Faraday cups of 120Te/128Te [0.002907(05)], 122Te/128Te [0.079646(10)], 123Te/128Te [0.027850(07)], 125Te/128Te [0.221988(09)], 126Te/128Te [0.592202(20)], and 130Te/128Te [1.076277(30)] were 0.140%, 0.014%, 0.026%, 0.005%, 0.004%, and 0.004%, respectively. The measured isotope ratio results are compared with previous results obtained by thermal ionization mass spectrometry (TIMS), negative thermal ionization mass spectrometry (N–TIMS), and MC–ICP–MS, showing an improvement in the precision about one order of magnitude for 120Te/128Te ratio. The present study shows better precision for Te isotope ratios compared to earlier studies.

On the anoxic Archean Earth, prior to the onset of oxidative weathering, electron acceptors were relatively scarce, perhaps limiting microbial productivity. An important metabolite may have been sulfate produced during the photolysis of volcanogenic SO 2 gas. Multiple sulfur isotope data can be used to track this sulfur source, and indeed this record indicates SO 2 photolysis dating back to at least 3.7 Ga, that is, as far back as proposed evidence of life on Earth. However, measurements of multiple sulfur isotopes in some key strata from that time can be challenging due to low sulfur concentrations. Some studies have overcome this challenge with NanoSIMS or optimized gas-source mass spectrometry techniques, but those instruments are not readily accessible. Here, we applied an aqua regia leaching protocol to extract small amounts of sulfur from whole rocks for analyses of multiple sulfur isotopes by multi-collector inductively coupled plasma mass spectrometry (MC-ICP-MS). Measurements of standards and replicates demonstrate good precision and accuracy. We applied this technique to meta-sedimentary rocks with putative biosignatures from the Eoarchean Isua Supracrustal Belt (ISB, >3.7 Ga) and found positive ∆ 33 S (1.40-1.80‰) in four meta-turbidites and negative ∆ 33 S (-0.80‰ and -0.66‰) in two meta-carbonates. Two meta-basalts do not display significant mass-independent fractionation (MIF, -0.01‰ and 0.16‰). In situ Re-Os dating on a molybdenite vein hosted in the meta-turbidites identifies an early ca. 3.7 Ga hydrothermal phase, and in situ Rb-Sr dating of micas in the meta-carbonates suggests metamorphism affected the rocks at ca. 2.2 and 1.7 Ga. We discuss alteration mechanisms and conclude that there is most likely a primary MIF-bearing phase in these meta-sediments. Our new method is therefore a useful addition to the geochemical toolbox, and it confirms that organisms at that time, if present, may indeed have been fed by volcanic nutrients., (© 2024 The Authors. Geobiology published by John Wiley & Sons Ltd.)

High concentrations of toxic cadmium (Cd) in soils are problematic as the element accumulates in food crops such as rice and cacao. A mitigation strategy to minimise Cd accumulation is to enhance the competitive uptake of plant-essential metals. Theobroma cacao seedlings were grown hydroponically with added Cd. Eight different treatments were used, which included/excluded hydroponic or foliar zinc (Zn) and/or iron (Fe) for the final growth period. Analyses of Cd concentrations and natural stable isotope compositions by multiple collector ICP-MS were conducted. Cadmium uptake and translocation decreased when Fe was removed from the hydroponic solutions, while the application of foliar Zn-EDTA may enhance Cd translocation. No significant differences in isotope fractionation during uptake were found between treatments. Data from all treatments fit a single Cd isotope fractionation model associated with sequestration (seq) of isotopically light Cd in roots and unidirectional mobilisation (mob) of isotopically heavier Cd to the leaves (ε 114 Cd seq-mob = -0.13‱). This result is in excellent agreement with data from an investigation of 19 genetically diverse cacao clones. The different Cd dynamics exhibited by the clones and seen in response to different Fe availability may be linked to similar physiological processes, such as the regulation of specific transporter proteins.

Combined determination of Cr and Ti isotopes of planetary materials offers a means with which to investigate their genetic relationship and the evolution of the protoplanetary disk. Here, we report the new sequential chemical separation procedure for combined Cr and Ti isotope ratio measurements. It comprises three steps: (a) Fe removal using AG1‐X8 anion exchange resin, (b) Ti separation using TODGA resin and (c) Cr separation using AG50W‐X8 cation exchange resin (with one additional step of Ti purification using AG1‐X8 anion exchange resin for samples having high Cr/Ti and Ca/Ti ratios). We applied the proposed procedure to terrestrial and meteorite samples with various compositions. Typical recovery rates of 90–100% were achieved with total procedural Cr and Ti blanks of 3–5 and 2–3 ng, respectively. We measured the Cr and Ti isotope compositions of the separated samples using thermal ionisation mass spectrometry and multiple collector‐inductively coupled plasma‐mass spectrometry, respectively. Our Cr and Ti isotope data were found to be consistent with those of previous studies of individual Cr and Ti isotopic compositions of the meteorites. These results demonstrate the capability of our separation method when applied to combined high‐precision Cr and Ti isotope analyses for single digests of planetary materials. Key Points: Sequential chemical separation for combined Cr and Ti isotope ratio measurements has been developed. Our new method enables isotope analyses of 3 μg of Cr and 1.5 μg of Ti. The combined isotope analyses of primitive meteorite components will facilitate understanding of the evolution of the proto‐planetary disk. [ABSTRACT FROM AUTHOR]

We present multitechnique U‐Pb geochronology and Hf isotopic data from zircon separated from rapakivi biotite granite within the Eocene Golden Horn batholith in Washington, USA. A weighted mean of twenty‐five Th‐corrected 206Pb/238U zircon dates produced at two independent laboratories using chemical abrasion‐isotope dilution‐thermal ionisation mass spectrometry (CA‐ID‐TIMS) is 48.106 ± 0.023 Ma (2s analytical including tracer uncertainties, MSWD = 1.53) and is our recommended date for GHR1 zircon. Microbeam 206Pb/238U dates from laser ablation‐inductively coupled plasma‐mass spectrometry (LA‐ICP‐MS) and secondary ion mass spectrometry (SIMS) laboratories are reproducible and in agreement with the CA‐ID‐TIMS date to within < 1.5%. Solution multi‐collector ICP‐MS (MC‐ICP‐MS) measurements of Hf isotopes from chemically purified aliquots of GHR1 yield a mean 176Hf/177Hf of 0.283050 ± 17 (2s, n = 10), corresponding to a εHf0 of +9.3. Hafnium isotopic measurements from two LA‐ICP‐MS laboratories are in agreement with the solution MC‐ICP‐MS value. The reproducibility of 206Pb/238U and 176Hf/177Hf ratios from GHR1 zircon across a variety of measurement techniques demonstrates their homogeneity in most grains. Additionally, the effectively limitless reserves of GHR1 material from an accessible exposure suggest that GHR1 can provide a useful reference material for U‐Pb geochronology of Cenozoic zircon and Hf isotopic measurements of zircon with radiogenic 176Hf/177Hf. Key Points: We suggest a new Eocene zircon reference material, GHR1.U‐Pb and Hf isotopic systematics in GHR1 zircon are homogeneous with a 206Pb/238U date of 48.106 +/‐ 0.023 Ma (2s) and a 176Hf/177Hf of 0.283050 +/‐ 17 (2s).GHR1 fulfills a need for abundant and easily available Cenozoic zircon reference materials. [ABSTRACT FROM AUTHOR]

Abstract We have optimized techniques to measure uranium and thorium isotopic compositions using secondary electron multiplier (SEM) and peak-jumping protocols on a multi-collector inductively coupled plasma mass spectrometer (MC-ICP-MS, Thermo Scientific Neptune Plus). This instrument is equipped with an advanced interface pump, X-skimmer cone, Jet sample cone, and desolvating nebulizer system (CETAC Aridus II) that enables overall ionization and transmission efficiency up to 3% for both U and Th. Approximately 50 fg 234U or 230Th can routinely yield a precision of 1–2‰ (2σ) for abundance and isotopic measurements. Non-linear behavior was not observed in the MasCom SEM with a retarding potential quadrupole in our MC-ICP-MS system when the beam intensity was limited to <∼1 × 106 cps. We performed a series of tests to examine the influence of tuning parameters, peak shift, and operating voltage of the SEM on isotopic measurements. Results for U/Th standards are consistent with published values and demonstrate the reliability of our protocols. Lastly, the precision and accuracy of 230Th ages based on U and Th isotope ratios is presented for a variety of carbonates, including both modern and secular-equilibrium samples. For corals as young as ∼10-yr old, we have significantly reduced the procedural chemistry blanks so that only 40 mg is required to yield an analytical precision of ±1.4 yr (2σ). All 230Th ages from modern and fossil corals and speleothems are in agreement with band counting ages. Highlights • An MC-ICP-MS SEM method was optimized to perform 230Th dating on carbonates. • Nonlinearity behavior was not observed on an SEM with energy filter activated. • With non-optimized tuning parameters, obtained U isotope ratios remained robust. • U and Th isotope determinations can tolerate a peak shift up to ±0.06 amu. • 230Th dates of coral and speleothem agree with their respective band counting ages. [ABSTRACT FROM AUTHOR]

Abstract Provenancing metal artifacts with scientific methods is an established tool in archeometry to identify the metal deposits, which were exploited for the production of ancient metal objects. It is thus an important method to reconstruct ancient exchange networks and the socio-economic organization of past societies. Previously introduced isotope-based approaches (Pb, Sr, Os) and chemical analyses of slag inclusions have severe limitations concerning their application or the amount of sample required. Fe isotopes were previously suggested in a quite early stage of investigation as a potential provenance tracer and it was postulated that they would not fractionate during the smelting procedure. However, previously published analytical data from iron ores indicate a wide overlap between deposits. Further, the earlier studies on Fe isotopes did not included bog iron ores, despite their high importance in ancient metallurgy. As geochemical reactions during ore formation are complex and fractionation cannot be generally excluded, the applicability of Fe isotopes as an alternative provenance tracer still asks for further investigation. This purely methodological study focuses on specimens from two sites of the formerly mined bog iron ore deposit Eyller Bruch (Germany), which are analyzed together with products of a smelting experiment based on these ores. The Fe isotopic composition of the bog iron ore from the investigated region suggests an intra-deposit zonation caused by environmental parameters and its overall variation is comparable with that of other deposits. The bog iron ore isotope signature largely overlaps with the isotope range of mineralizations in other regions. As a consequence of this and although the absence of Fe isotope fractionation during the smelting procedure is confirmed, the study demonstrates the lack of discriminatory power of Fe isotopes for provenance studies. Potential applications for archeometry can rather be found in the environmental parameters, especially organic matter, which seems to have a strong influence on Fe isotope compositions of bog iron ores. Zonations within deposits might be identified and could help to reconstruct the exploitation history of the deposit or to reconstruct past bog landscapes. Highlights • Iron isotopes for ancient iron metal tracing revisited. • Bog ores from one deposit substantially overlap with nearly all other ore types. • Iron isotopes lack for discriminatory power for provenance studies. • Bog ores in a single deposit might be differentiated according to their host soil. [ABSTRACT FROM AUTHOR]

Abstract Laboratory batch experiments were conducted to study Mo isotope fractionation during the precipitation of powellite (CaMoO 4) and wulfenite (PbMoO 4). These minerals act as important sinks of dissolved Mo, especially in alkaline-pH mine drainage. Their precipitation might be traceable through Mo isotope analyses, provided that it induces Mo isotope fractionation. Experiments involved the presence/absence of dissolved sulfate and inorganic carbon (DIC) to better mimic the aqueous chemistry of mine drainage, as these constituents are characteristic of mine waters. Molybdate minerals preferentially incorporated light Mo isotopes from aqueous solution with fractionation patterns that are linked to the saturation state. The Rayleigh fractionation model was most suitable to describe powellite precipitation under supersaturated conditions. The average Rayleigh isotope separation factor for powellite precipitation was −0.82 ± 0.12‰, with no significant effect from the presence/absence of sulfate and DIC. Upon approaching chemical equilibrium, bidirectional exchange of molybdate between dissolved Mo and powellite led to a pronounced release of isotopically light Mo to solution, which overrode the Rayleigh fractionation pattern formed at early time. Molybdenum isotope data during wulfenite precipitation could reasonably be fitted using the Rayleigh and equilibrium fractionation models, which yielded isotope separation factors of −0.25 ± 0.10‰ and −0.75 ± 0.07‰, respectively. These results contribute to a growing knowledge of Mo isotope fractionation during processes of dissolved Mo removal (e.g., adsorption and precipitation), thus far all of which show that an enrichment in heavy Mo isotopes in solution is indicative of Mo attenuation. [ABSTRACT FROM AUTHOR]

Tin isotope ratios may be a useful tool for tracing back the tin in archaeological metal artefacts (tin metal, bronze) to the geological source and could provide information on ancient smelting processes. This study presents the results of laboratory experiments, which reduced (smelted) synthetic stannic oxide, natural cassiterite and corroded archaeological tin and bronze objects. The overall aim of the study is to find a reliable method for the decomposition of tin ores and corrosion products in order to determine their tin isotopic composition, and to explore possible effects on the tin isotope ratios during pyrometallurgy. We focused on five methods of reduction at high temperatures (900-1100 °C): reduction with CO (plain smelting), reduction with KCN/CO (cyanide reduction), reduction with Na2CO3/CO, reduction with Cu/CO ('cementation technique') and reduction with CuO/CO ('co-smelting'). The smelting products are analysed by means of optical and scanning electron microscopy as well as X-ray diffraction, while their isotope composition is determined with a high-resolution multi-collector mass spectrometer with inductively coupled plasma ionisation. The results show that all five methods decompose synthetic stannic oxide, cassiterite and corrosion products. Ultimately, reduction with KCN is the best solution for analysing tin ores and tin corrosion because the chemical processing is straightforward and it provides the most reproducible results. Reduction with Na2CO3 and copper is an alternative, especially for bronze corrosion, but it requires laborious chemical purification of the sample solutions. In contrast, evaporation of tin and incomplete alloying during plain smelting and co-smelting can cause considerable fractionation among smelting products (Δ124Sn = 0.10 ‰ (0.03 ‰ u−1)). A less precise and even inaccurate determination of the tin isotopic compositions of the tin ores would be the consequence. However, the results of this study help to evaluate the possible influence of the pyrometallurgical processes on the tin isotope composition of tin and bronze artefacts. [ABSTRACT FROM AUTHOR]

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We report high‐precision cadmium isotope ratios for a series of standard solutions and geological reference materials for interlaboratory comparison. Complete separation of Cd from a matrix in geological samples was achieved using AG MP‐1M anion exchange resin with > 97.8% recovery. Cadmium isotope ratios were measured by both Neptune plus multi‐collector‐inductively coupled plasma‐mass spectrometry (MC‐ICP‐MS) and Nu Plasma II MC‐ICP‐MS at low‐resolution mode. Both sample calibrator bracketing (SSB) and double‐spike techniques (DS) were utilised for mass bias correction. Cadmium isotope ratio data of standard solutions (BAM I012 Cd, SPEX Cd, Alfa Aesar Cd, GSB Cd) and geological reference materials (GSS‐1, GXR‐1, GXR‐2, GSD‐12, NIST SRM 2711a) are reported relative to Cd solution (NIST SRM 3108). The intermediate precision over a three‐year period was better than ± 0.09‰ (2s) for δ114Cd/110Cd and ± 0.06‰ (2s) for δ112Cd/110Cd ratios. SPEX Cd was used as a secondary reference material for Cd isotopic measurement with a δ114/110CdNISTSRM3108 value of −2.13 ± 0.09‰ (2s). The soil reference material NIST SRM 2711a has a significantly heavier isotopic composition than other soil materials, GXR‐1, GXR‐2 and GSS‐1. New recommended values are presented for future interlaboratory calibration. Key Points: High‐precision cadmium isotope ratios were reported relative to NIST SRM 3108. The intermediate precision over a three‐year period was better than ±0.09‰ (2s) for δ114/110CdNIST SRM 3108. New recommended values are presented for future interlaboratory calibration. [ABSTRACT FROM AUTHOR]

Twenty‐two objects of glass from the Decapolis city of Gerasa, N. Jordan, with characteristic vessel forms ranging from Hellenistic to Early Islamic (2nd century BCE to 8th century CE) were analyzed for major and trace elements, and 16 samples for Sr‐isotopes. The majority were produced in the vicinity of Apollonia on the Palestine coast in the 6th–7th centuries CE, and strong inter‐element correlations for Fe, Ti, Mn, Mg, Nb reflect local variations in the accessory minerals in the Apollonia glassmaking sand. The ubiquity of recycling is reflected in elevated concentrations and high coefficients of variation of colorant‐related elements as well as a strong positive correlation between K and P. The high level of K contamination is attributed to the use of pomace (olive processing residue) as fuel, and a negative correlation with Cl, due to volatilization as the glass was reheated. This points to an efficient system for the collection of glass for recycling in Jerash during the latter part of the first millennium CE. Differences in elemental behavior at different sites in the Levant may reflect the context of the recycling system, for example, glass from secular contexts may contain less colorants derived from mosaics than glass associated with churches. [ABSTRACT FROM AUTHOR]

The capabilities of Cu isotope ratio measurements are often restricted by the small volumes of sample available and/or their low Cu concentration. In this work, an analytical approach was developed for performing Cu isotopic analysis via multi-collector ICP-mass spectrometry (MC-ICP-MS) at ultra-trace level using Ga as an internal standard for mass bias correction. The minimum concentration of Cu required for accurate and precise isotope ratio measurements was established to be 20 μg L −1 with wet plasma conditions and 5 μg L −1 with dry plasma conditions. The use of Ga as an internal standard for mass bias correction provided several advantages compared to Ni, i.e. improved internal precision on δ 65 Cu values and lower blank levels. Ga can also be used at a 4-fold lower concentration level than Ni. However, in wet plasma conditions, the signals of 36 Ar 16 O 2 1 H + and 40 Ar 15 N 16 O + interfered with the signals of 69 Ga + and 71 Ga + , respectively, while in dry plasma conditions, realized by the use of a desolvation unit, 69 Ga + suffered from spectral interference from 40 Ar 14 N 2 1 H + . These interferences were resolved by using medium mass resolution. For validation purposes, the approach was applied to commercially available blood and serum samples. The δ 65 Cu values for the samples measured at a concentration level of 5 μg L −1 Cu and 5 μg L −1 Ga using dry plasma conditions were in good agreement with those obtained for isotope ratio measurements at the “standard” concentration level of 200 μg L −1 Cu and 200 μg L −1 Ni using wet plasma conditions. In addition, the δ 65 Cu values obtained for micro-samples of serum/blood (volume of 100 µL) were in good agreement with the corresponding ones obtained using the “standard” volume for isotopic analysis (500 μL). [ABSTRACT FROM AUTHOR]

Copper isotope ratios differ between hypogene sulfidic, supergene sulfidic and oxidized ore sources. Traditional lead isotope signatures of ancient metals are specific to deposits, while Cu isotope signatures are specific to the types of ore minerals used for metal production in ancient times. Two methodological case studies are presented: First, the mining district of Faynan (Jordan) was investigated. Here, mainly oxidized copper ores occur in the deposits. The production of copper from Fayan’s ore sources is confirmed by the measurement of the Cu isotope signature of ingots from the Early Bronze Age metal workshop from Khirbat Hamra Ifdan. Based on our results illustrating differences in the Cu isotope composition between the ore mineralizations from Timna (Israel) and Faynan, it is now possible to determine these prehistoric mining districts from which copper artifacts originated by combining trace elements and Pb isotopes with Cu isotopes. The second case study presents data on Late Bronze Age copper production in Cyprus. Oxhide ingots from the shipwreck of Uluburun (Turkey) were tested for their lead isotope signatures and assigned to Cypriot deposits in the recent decades. The oxhide ingots from Uluburun show a Cu isotope signature which we also found for oxidized copper ores from Cyprus, while younger oxhide ingots as well as metallurgical slag from the Cypriot settlements Kition and Enkomi show a different signature which might be due to the use of sulfidic ore sources from a greater depth of deposits. We assert that there could be a chronological shift from oxidized to sulfidic ore sources for the copper production in Cyprus, requiring different technologies. Therefore, Cu isotopes can be used as a proxy to reconstruct mining and induced smelting activities in ancient times. [ABSTRACT FROM AUTHOR]

Mass fractions of Sn and In were determined in sixteen geological reference materials including basaltic/mafic (BCR‐2, BE‐N, BHVO‐1, BHVO‐2, BIR‐1, OKUM, W‐2, WS‐E), ultramafic (DTS‐2b, MUH‐1, PCC‐1, UB‐N) and felsic/sedimentary reference materials (AGV‐2, JA‐1, SdAR‐M2, SdAR‐H1). Extensive digestion and ion exchange separation tests were carried out in order to provide high yields (> 90% for Sn, > 85% for In), low total procedural blanks (~ 1 ng for Sn, < 3 pg for In) and low analytical uncertainties for the elements of interest in a variety of silicate sample matrices. Replicate analyses (n = 2–13) of Sn–In mass fractions gave combined measurement uncertainties (2u) that were generally < 3% and in agreement with literature data, where available. We present the first high‐precision In data for reference materials OKUM (32.1 ± 1.5 ng g−1), DTS‐2b (2.03 ± 0.25 ng g−1), MUH‐1 (6.44 ± 0.30 ng g−1) and PCC‐1 (3.55 ± 0.35 ng g−1) as well as the first Sn data for MUH‐1 (0.057 ± 0.010 μg g−1) and DTS‐2b (0.623 ± 0.018 μg g−1). [ABSTRACT FROM AUTHOR]

The multiple collector inductively coupled plasma mass spectrometer (MC-ICP-MS) is booming to be a high-precision, fast, and accurate instrument in measuring lithium (Li) isotopes. Modified highly sensitive Jet sample and X skimmer cones have largely upgraded analytical sensitivity and reduced sample consumption with distinct instrumental mass bias behaviors. Herein, four available combinations of the sample and skimmer cones [Jet sample cone + X skimmer cone (Jet + X), Standard sample cone + X skimmer cone (Standard + X), Standard sample cone + H skimmer cone (Standard + H), and Jet sample cone + H skimmer cone (Jet + H)] were tested for their effects on peak shape, sensitivity, mass bias behavior, and accuracy and precision of Li isotopic measurements in solution mode. The results showed that all four combinations were able to attain an ideal peak shape by adjusting the associated parameters, with a positively linear relation between 7 Li (and 6 Li) signals and Li concentrations. For a given Li concentration, the sensitivities were enhanced 3–7 times using the Standard + X, the Jet + H, and the Jet +X combinations compared to that of using the Standard + H. The enhanced sensitivity is attributable to more plasma ions introduced into the mass spectrometer through the Jet and X cones. Mass bias is distinct for different cone combinations, with a slight difference with various Li concentrations, indicating the neccesity of concentration match during measurement. Among the four cone combinations, the best reproducibility can be obtained by using the Standard + X cones to determine precise and accurate Li isotopes for samples. Furthermore, a pretreatment by 5% HNO 3 and 0.1% HF, and then 2% HNO 3 prior to analyses can minimize the memory effect of Li. [ABSTRACT FROM AUTHOR]

Mercury ( Hg) concentrations and stable isotopes along with other trace metals were examined in environmental samples from Ecuador and Peru's shared Puyango-Tumbes River in order to determine the extent to which artisanal- and small-scale gold mining (ASGM) in Portovelo-Zaruma, Ecuador contributes to Hg pollution in the downstream aquatic ecosystem. Prior studies investigated the relationship between ASGM activities and downstream Hg pollution relying primarily on Hg concentration data. In this study, Hg isotopes revealed an isotopically heavy Hg signature with negligible mass independent fractionation (MIF) in downstream sediments, which was consistent with the signature observed in the ASGM source endmember. This signature was traced as far as ∼120 km downstream of Portovelo-Zaruma, demonstrating that Hg stable isotopes can be used as a tool to fingerprint and trace sources of Hg over vast distances in freshwater environments. The success of Hg isotopes as a source tracer in fresh waters is largely due to the particle-reactive nature of Hg. Furthermore, the magnitude and extent of downstream Hg, lead, copper and zinc contamination coupled with the Hg isotopes suggest that it is unlikely that the smaller artisanal-scale activities, which do not use cyanidation, are responsible for the pollution. More likely it is the scale of ores processed and the cyanide leaching, which can release other metals and enhance Hg transport, used during small-scale gold mining that is responsible. Thus, although artisanal- and small-scale gold mining occur in tandem in Portovelo-Zaruma, a distinction should be made between these two activities. [ABSTRACT FROM AUTHOR]

We report stable cerium (Ce) isotopic compositions of terrestrial rocks and investigate Ce isotopic fractionation during column chemistry in this study. Cerium was separated from matrix elements by a single-stage extraction technique using Eichrom DGA resin. Ce isotope ratios were measured using a Thermo Scientific Neptune Plus MC-ICP-MS employing a sample–standard combined with a Sm-doping method. The data accuracy and precision of Ce isotope analyses were rigorously examined by two different laboratories. The δ142Ce values of mono-elemental Ce standards (JMC304 and CDUT-Ce) relative to NIST SRM 3110 solution were − 0.005 ± 0.042‰ (2SD, N = 9) and 0.118 ± 0.033‰ (2SD, N = 6), respectively. The δ142Ce of the manganese nodule (NOD-P-1) measured in two laboratories were 0.177 ± 0.035‰ (2SD, N = 7) and 0.172 ± 0.034‰ (2SD, N = 8), respectively; NOD-A-1 were 0.116 ± 0.028‰ (2SD, N = 8) and 0.104 ± 0.028‰ (2SD, N = 9), respectively. The offset between these two manganese nodules could be possibly related with their unique diagenetic environments. The δ142Ce of two USGS standards diabase W-2a was −0.036 ± 0.046‰ (2SD, N = 3), basalt BHVO-2 was −0.019 ± 0.036‰ (2SD, N = 4). Ce isotopic compositions of three Chinese reference standards granite gneiss GBW07121, diabase GBW07123, and stream sediment GBW07301a were 0.039 ± 0.033‰ (2SD, N = 5), 0.068 ± 0.027‰ (2SD, N = 5) and 0.046 ± 0.015‰ (2SD, N = 3), respectively. The reported data will be helpful for quality assurance and inter-laboratory comparison for high-precision Ce isotopic studies. Full recovery is important to achieve high precision and high accuracy data for metal isotopes. To understand Ce isotope behavior during column separation, an experiment with different Ce cuts was conducted. The δ142Ce of JMC304 and NIST SRM 3110 in five different Ce subcuts varied from 0.047 ± 0.020‰ (2SD, N = 3; 0–25% cut) to −0.029 ± 0.047‰ (2SD, N = 5; 45–100% cut), and 0.058 ± 0.047‰ (2SD, N = 4; 0–11% cut) to −0.022 ± 0.033‰ (2SD, N = 4; 32–100% cut), respectively. δ142Ce of these subcuts showed small ranges, but isotopic fractionation of Ce did occur during column chemistry and light isotopes are preferentially retained in the DGA resin. • High-precision Ce isotopic compositions of various standards were reported. • Detectable Ce isotope fractionation occurs during the low-temperature process. • Ce isotopic fractionation occurs during column chemistry. [ABSTRACT FROM AUTHOR]

In this study we utilize an all-faraday cup detector configuration on the Neoma MC-ICP-MS to perform uranium isotope ratio determinations from certified reference materials and a nuclear fuel precursor material via solution and laser ablation based sampling methodologies. The goal in performing these measurements is primarily to demonstrate that the all-faraday cup method can produce highly precise and accurate isotope ratios even at relatively low signal intensity levels while also developing a preliminary understanding of how the complex interplay between different amplifier resistor levels (e.g. 1011 vs 1013 Ω) and integration times impacts the precision and accuracy of different types of measurements. Our results show that the faraday cups with 1013 Ω resistors in their amplifier feedback loops can be used to produce accurate and relatively precise isotope ratios for ion beams down to ∼5 K cps. However, at the lower end of the signal intensities observed in this study, longer integration times are necessary to mitigate the impact of ion beam instability that can occur during laser ablation based sampling. Despite this potential limitation, the all-faraday cup method is highly versatile as exemplified by the analysis of a collection of uranium reference materials with highly variable uranium isotopic compositions. [Display omitted] • Uranium isotope ratio measurement are made via solution and laser ablation on a Neoma MC-ICP-MS • An all faraday detector collector configuration is utilized • Faraday detectors with 1013 Ω resistors allow for minor uranium isotopes to be accurately detected and quantified • Different integration times and instrumental parameters are explored [ABSTRACT FROM AUTHOR]

Antimony (Sb) is a metalloid element with potential toxicity and carcinogenicity, and is ubiquitous in our living environment. Sb pollution has become a serious global problem, which has been induced by combustion of fossil fuel and Sb-containing waste as well as mining activities. However, Sb geochemical cycle in environment systems and its inherent hazards to human and ecosystem health are poorly known. Sb isotope technology provides a novel method to counter this challenge. Sb isotopic ratio could not be measured precisely until the introduction of the multiple-collector inductively coupled plasma mass spectrometry (MC-ICP-MS) at the beginning of the 20th century. This paper systematically reviewed the analytical methods of Sb isotopes, including pre-concentration and separation methods of thiol cotton fiber (TCF) and ion-exchange chromatography, measurement techniques of MC-ICP-MS with hydride generation (HG) and metal doping. Additionally, the Sb isotope fractionation mechanism was summarized in biological, reduction, adsorption, evaporation, precipitation and mixing processes. The Sb isotope application research status is also reviewed, such as illustrating Sb sources and its characteristics of migration and transformation in hydrologic system. Finally, future prospects for Sb isotopes in environmental systems have been proposed, which will promote the advances in the study of Sb pollution and its prevention significantly. [ABSTRACT FROM AUTHOR]

Abstract: The redox‐sensitive, chalcophile, and volatile Se stable isotope system offers new perspectives to investigate the origin and evolution of terrestrial volatiles and the roles of magmatic and recycling processes in the development of the redox contrast between Earth's reservoirs. Selenium isotope systematics become more robust in a well‐constrained petrogenetic context as can be inferred from Se‐Te elemental signatures of sulfides and igneous rocks. In this study, we present a high‐yield chemical sample processing method that allows the determination of Se‐Te concentrations and Se isotope composition from the same sample digest of silicate rocks by hydride generation isotope dilution (ID) quadrupole inductively coupled plasma mass spectrometry (ICP‐MS) and double spike (DS) multicollector (MC)‐ICP‐MS, respectively. Our procedure yields ∼80% Se‐Te recoveries with quantitative separation of relevant interfering elements such as Ge and HG‐buffering metals. Replicate analyses of selected international reference materials yield uncertainties better than 0.11‰ (2 s.d.) on δ82/76Se and 3% (r.s.d.) on Se concentration for DS MC‐ICP‐MS determinations for as low as ∼10 ng sample Se. The precision of Se‐Te concentration measurements by ID ICP‐MS is better than 3% and 5% (r.s.d.) for total amounts of ∼0.5–1 ng Se and ∼0.2–0.5 ng Te, respectively. The basaltic reference materials have variable Se‐Te contents, but their δ82/76Se values are rather uniform (on average 0.23 ± 0.14‰; 2 s.d.) and different from the chondritic value. This altogether provides the methodology and potential to extend the limited data set of coupled Se isotope and Se‐Te elemental systematics of samples relevant to study the terrestrial igneous inventory. [ABSTRACT FROM AUTHOR]

This GGR biennial critical review covers developments and innovations in key analytical methods published since January 2014, relevant to the chemical, isotopic and crystallographic characterisation of geological and environmental materials. In nine selected analytical fields, publications considered to be of wide significance are summarised, background information is provided and their importance evaluated. In addition to instrumental technologies, this review also presents a summary of new developments in the preparation and characterisation of rock, microanalytical and isotopic reference materials, including a précis of recent changes and revisions to ISO guidelines for reference material characterisation and reporting. Selected reports are provided of isotope ratio determinations by both solution nebulisation MC-ICP-MS and laser ablation-ICP-MS, as well as of radioactive isotope geochronology by LA-ICP-MS. Most of the analytical techniques elaborated continue to provide new applications for geochemical analysis; however, it is noted that instrumental neutron activation analysis has become less popular in recent years, mostly due to the reduced availability of nuclear reactors to act as a neutron source. Many of the newer applications reported here provide analysis at increasingly finer resolution. Examples include atom probe tomography, a very sensitive method providing atomic scale information, nanoscale SIMS, for isotopic imaging of geological and biological samples, and micro-XRF, which has a spatial resolution many orders of magnitude smaller than conventional XRF. [ABSTRACT FROM AUTHOR]

Measurements of molybdenum (Mo) stable isotopes (δ 98 Mo) were applied along with conventional geochemical analyses of water and rock samples at a Mo mine in the USA to assess controls on Mo mobility in two unsaturated waste-rock storage facilities (WRSFs) that are differentiated by acidic and alkaline drainages. Unweathered waste rock, Mo ore, and mine tailings from the site were also analyzed to constrain the isotopic composition of the source of Mo entering mine drainage via weathering processes. The surfaces of weathered waste-rock samples were sequentially leached using a two-step chemical extraction to determine the distribution and isotopic composition of Mo among primary and secondary mineral assemblages. The observed variation in δ 98 Mo among all samples exceeded 5‰. The δ 98 Mo of Mo-rich (>340 μg/L) mine process water and pit wall runoff ranged from 0.6 to 0.7‰, which was equal within error to the average δ 98 Mo of waste rock, tailings, and ore samples and indicated negligible isotopic fractionation during molybdenite oxidative dissolution. In contrast, drainage from the base of both waste-rock storage facilities was isotopically heavier, ranging from 1.6 to 1.9‰. Coupled δ 98 Mo and Mo/SO 4 2- ratios in mine drainage and sequential chemical extractions of weathered waste-rock surfaces indicated that Mo adsorption onto mineral surfaces was most likely driving the increase in δ 98 Mo in drainage from both WRSFs. Molybdenum stable isotope data provided a powerful tracer of processes controlling Mo mobility when used in conjunction with conventional geochemical analyses. [ABSTRACT FROM AUTHOR]

The isotopic compositions of Se in natural materials can be measured by multiple collector inductively coupled plasma mass spectrometry (MC-ICP-MS) in combination with hydride generation and desolvation device. Although oceans are important targets for research, precise isotopic analysis of Se in seawater is generally difficult owing to its low concentrations and the much higher concentrations of other elements. We developed a robust, accurate method for the precise determination of Se isotopic composition in seawater. A hydride generator combined with a desolvation device with methane addition was coupled to MC-ICP-MS to measure Se isotopes precisely. Two new thiol resins were used to preconcentrate and separate Se from the seawater matrix efficiently, and Se was quickly eluted by small amounts of concentrated HNO 3 . No detectable Se isotope fractionation was observed during the preconcentration and separation procedure. The carbon-containing plasma increased Se sensitivity, suppressed the spectral interference signal, and improved precision by > 3 times. The precisions (2sd, n = 24) of Merck Se standard solutions for δ 82/78 Se, δ 82/77 Se, and δ 82/76 Se were 0.07‰, 0.10‰, and 0.16‰, respectively. The δ 82/76 Se values of standard solutions agreed well with results obtained by other research groups. The method was used to obtain a depth profile for dissolved inorganic Se (DISe) isotopes in seawater from the Northwestern Pacific Ocean. The range of δ 82/76 DISe was 0.41‰ to 1.59‰, indicating that Se isotopes fractionate sufficiently to clarify the biogeochemical cycling of this element in the ocean. [ABSTRACT FROM AUTHOR]

We propose an improved method for precise sulfur isotopic measurements by multi-collector inductively coupled plasma mass spectrometry (MC-ICP-MS) in conjunction with a membrane desolvation nebulization system. The problems of sulfur loss through the membrane desolvation apparatus are carefully quantified and resolved. The method overcomes low intrinsic sulfur transmission through the instrument, which was initially 1% when operating at a desolvation temperature of 160 °C. Sulfur loss through the membrane desolvation apparatus was resolved by doping with sodium. A Na/S ratio of 2 mol mol −1 produced sulfur transmissions with 98% recovery. Samples of 3 nmol (100 ng) sulfur achieved an external precision of ±0.18‰ (2 SD) for δ 34 S and ±0.10‰ (2 SD) for Δ 33 S (uppercase delta expresses the extent of mass-independent isotopic fractionation). Measurements made on certified reference materials and in-house standards demonstrate analytical accuracy and reproducibility. We applied the method to examine microbial-induced sulfur transformation in marine sediment pore waters from the sulfate-methane transition zone. The technique is quite versatile, and can be applied to a range of materials, including natural waters and minerals. [ABSTRACT FROM AUTHOR]

Herein, we describe the use of a Nu Plasma 1700 multi-collector inductively coupled plasma mass spectrometer (MC-ICP-MS) in true high-resolution mode to determine Fe isotopic ratios at the center of Fe peaks instead of their shoulders. A standard-sample bracketing (SSB) technique and a Ni doping method were used for instrumental mass bias calibration. The effects of Fe/Ni ratio and plasma mode were investigated in order to establish a high-precision Fe isotope analysis method. The results showed that the Ni-doping method provided more precision isotopic ratios than that of the SSB technique. Moreover, this work also presents Fe isotopic compositions of some geological reference materials (BCR-2, BHVO-2, AGV-2, GSR-1, GSR-2, GSR-3, GSP-2, and DSN-1), which were highly accurate with respect to the international Fe isotope standard IRMM-014. The iron isotopic compositions of most geological reference materials measured in this study agreed with the previously published data within quoted analytical uncertainties. Long-term reproducibility analyses of all samples indicate that the obtained isotopic ratios are highly reproducible, with precisions of better than ±0.03‰ for δ 56 Fe (2 sd) and ±0.06‰ (2 sd) for δ 57 Fe. Our results demonstrated the usefulness of internal element doping for improving the stability and precision of isotope analysis by MC-ICP-MS. [ABSTRACT FROM AUTHOR]

Lead (Pb) isotopes have been extensively employed in tracing sources of Pb and its transport pathways through the environment. However, Pb isotopic ratios in related geochemical reference materials are scarce. Here, we report high-precision Pb isotopic ratios measured by Nu Plasma II MC-ICP-MS using calibrated Tl/Tl = 2.38865 (NIST SRM 997) for mass discrimination correction. The long-term external precision (2SD) for NIST SRM 981 of Pb, BCR-2, and BHVO-2 are 0.31‰ (n = 105), 0.42‰ (n = 11), and 0.25‰ (n = 5) for Pb/Pb and 0.16‰, 0.53‰, and 0.07‰ for Pb/Pb, both respectively, and their Pb isotopic ratios are in excellent agreement with the recommended values. Using this method, we report for the first time Pb isotopic compositions in shale SGR-1b (USGS); coal CLB-1 (USGS); stream sediments GSD-17, -21, and -23 (IGGE); soils GSS-12, -13, -14, -15, and -16 (IGGE); plants GSV-1, -2, and -3 (IGGE); and human hair GSH-1(IGGE). [ABSTRACT FROM AUTHOR]

This study uses MC-ICP-MS for the precise analysis of the stable tin isotopic composition in ore minerals of tin (cassiterite, stannite), tin metal and tin bronze. The ultimate goal is to determine the provenance of tin in ancient metal objects. We document the isotope compositions of reference materials and compare the precision of different isotope ratios and the accuracy of different procedures of mass fractionation correction. These data represent a base with which isotopic data of future studies can be directly compared. The isotopic composition of cassiterite and stannite can be determined after reduction to tin metal and bronze, respectively. Both metals readily dissolve in HCl, but while the solutions of tin metal can be directly measured, the bronze solutions must be purified with an anion exchanger. The correction of the mass bias is best performed with an internal Sb standard and an empirical regression method. A series of Sn isotope determinations on commercially available mono-element Sn solutions as well as reference bronze materials and tin minerals show fractionations ranging from about −0.09‰ to 0.05‰/amu. The combined analytical uncertainty (2 s) was determined by replicate dissolutions of reference materials of bronze (BAM 211, IARM-91D) and averages at about 0.005‰/amu. [ABSTRACT FROM AUTHOR]

Silicon isotope determination of sulfur-rich samples by MC- ICP- MS can be challenging because cation-exchange chromatography used for Si purification does not efficiently remove anionic sulfur species. Results for pure Si standard solutions with addition of sulfate showed shifts of up to +1.04 ± 0.10‰ (2 s) in δ30Si. Doping of both standard solutions and samples with S to a fixed S/Si ratio can eliminate the relative change in instrumental mass fractionation due to variable S/Si in samples and also boosts the relative sensitivity of Si by up to 66%. Moreover, Fe hydroxide precipitation during sample processing adsorbs Si resulting in isotopic fractionations. Tests using Fe-rich samples showed that this could be a major factor for observed shifts in δ30Si. Acidification of the sample and standard solutions to a pH < 1 aggressively dissolved any Fe hydroxide precipitates, even in relatively Fe-rich samples such as chondrite meteorites. The pH values of the sample solutions were subsequently adjusted to a range of 2-3 by adding ultra-pure Na OH solutions. The combination of sulfur doping and the pH adjustment protocol ensured a full recovery of Si and proved to be an efficient and reliable method for Si isotope determination of S- and Fe-rich materials. [ABSTRACT FROM AUTHOR]

A lead isotopic standard solution with natural abundance has been developed by applying a mixture of a solution of enriched 208 Pb and a solution of enriched 204 Pb ( 208 Pb- 204 Pb double spike solution) as bracketing method. The amount-of-substance ratio of 208 Pb: 204 Pb in this solution is accurately measured by applying EDTA titrimetry, which is one of the primary measurement methods, to each enriched Pb isotope solution. Also metal impurities affecting EDTA titration and minor lead isotopes contained in each enriched Pb isotope solution are quantified by ICP-SF-MS. The amount-of-substance ratio of 208 Pb: 204 Pb in the 208 Pb- 204 Pb double spike solution is 0.961959 ± 0.000056 (combined standard uncertainty; k = 1). Both the measurement of lead isotope ratios in a candidate isotopic standard solution and the correction of mass discrimination in MC-ICP-MS are carried out by coupling of a bracketing method with the 208 Pb- 204 Pb double spike solution and a thallium internal addition method, where thallium solution is added to the standard and the sample. The measured lead isotope ratios and their expanded uncertainties ( k = 2) in the candidate isotopic standard solution are 18.0900 ± 0.0046 for 206 Pb: 204 Pb, 15.6278 ± 0.0036 for 207 Pb: 204 Pb, 38.0626 ± 0.0089 for 208 Pb: 204 Pb, 2.104406 ± 0.00013 for 208 Pb: 206 Pb, and 0.863888 ± 0.000036 for 207 Pb: 206 Pb. The expanded uncertainties are about one half of the stated uncertainty for NIST SRM 981, for 208 Pb: 204 Pb, 207 Pb: 204 Pb and 206 Pb: 204 Pb, or one eighth, for 208 Pb: 206 Pb and 207 Pb: 206 Pb, The combined uncertainty consists of the uncertainties due to lead isotope ratio measurements and the remaining time-drift effect of mass discrimination in MC-ICP-MS, which is not removed by the coupled correction method. In the measurement of 208 Pb: 204 Pb, 207 Pb: 204 Pb and 206 Pb: 204 Pb, the latter contribution is two or three times larger than the former. When the coupling of a bracketing method with the 208 Pb- 204 Pb double spike solution and a thallium internal addition method is applied to the analysis of NIST SRM 981, the measured lead isotope ratios are in good agreement with its certified values. This proves that the developed method is not only consistent with the conventional one by NIST SRM 981 but also enables measurement of the lead isotope ratios with higher precision. [ABSTRACT FROM AUTHOR]

Tin is a volatile as well as chalcophile and siderophile element, and this geochemical behaviour gives rise to a broad range of potential applications for Sn as a stable isotope tracer in geological processes. We present the first high-precision method to analyse the stable isotopic composition of Sn in geological materials using ion-exchange chromatography and double-spike multi-collector inductively-coupled-plasma mass-spectrometry (MC-ICPMS). We apply these methods to analyse the Sn stable isotopic composition of four geological reference materials, including a number of replicate digestions of BHVO-2 and BCR-2 to assess the reproducibility of the technique. Tin was purified prior to analysis using TRU resin to remove matrix and interfering elements. Isotopic ratios were measured using a Thermo-Fischer Neptune Plus MC-ICPMS combined with a 117 Sn– 122 Sn double-spike to correct for any mass dependent fractionation resulting from instrumental mass bias or incomplete yields from chemical purification. Results are expressed in delta notation as δ 122/118 Sn, representing the per mil (‰) difference in the 122/118 Sn ratio of the sample relative to our in-house standard Sn_IPGP. Based on replicate analyses of the USGS reference materials BHVO-2 and BCR-2, we estimate the external reproducibility to be ca. ± 0.065‰ (2 sd) on the δ 122/118 Sn ratio, or ca. ± 0.016‰ per amu. Analyses of these plus two additional USGS reference materials, AGV-2 and GSP-2, show a large range (>0.2‰ on δ 122/118 Sn) of Sn stable isotopic compositions that are correlated with igneous differentiation indicators (e.g. SiO 2 content), indicating that Sn isotopes are fractionated during igneous processes. These results indicate significant potential for Sn stable isotopes as a tracer of magmatic differentiation and the redox state of the mantle. In addition, Sn stable isotopes may prove useful in tracing diverse geological processes such as volatilisation/condensation and metal–silicate/metal–sulphide differentiation. [ABSTRACT FROM AUTHOR]

In comparison to isotope analysis of dissolved samples femtosecond laser ablation multicollector inductively coupled plasma mass spectrometry (fs-LA-MC-ICP-MS) enables precise isotope ratio analyses consuming much less sample material and with a minimum effort in sample preparation. This is especially important for the investigation of valuable historical objects for which visual traces of sampling are unwanted. The present study provides a basis for tin isotope ratio measurements using LA-MC-ICP-MS technique. For this, in house isotope standards had to be defined. Investigations on interferences and matrix effects illustrate that beside Sb only high Te contents (with values above those to be expected in cassiterite) result in a significant shift of the measured tin isotope ratios. This effect can partly be corrected for using natural isotope abundances. However, a natural isotope fractionation of Te cannot be excluded. Tin beads reduced from cassiterite were analysed by laser ablation and after dissolution. It was shown that tin isotope ratios can be determined accurately by using fs-LA-MC-ICP-MS. Furthermore the homogeneity of tin isotope ratios in cassiterite was proven. [ABSTRACT FROM AUTHOR]