Calcium Carbonate and Phosphate Reference Materials for Monitoring Bulk and Microanalytical Determination of Sr Isotopes

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Homogeneity, mass fractions of about forty trace elements and Sr isotope composition of Ca carbonate reference materials (RMs) between original and nano‐powdered pellets are compared. Our results using nanosecond and femtosecond LA‐(MC)‐ICP‐MS show that the nano‐pellets of the RMs MACS‐3NP, JCp‐1NP and JCt‐1NP are about a factor of 2–3 more homogeneous than the original samples MACS‐3, JCp‐1 and JCt‐1, and are therefore much more suitable for microanalytical purposes. With the exception of Si, the mass fractions of the synthetic RM MACS‐3 agree with its fine‐grained analogue MACS‐3NP. Very small, but significant, differences between original and nano‐pellets are observed in the RMs JCp‐1 and JCt‐1 for some trace elements with very low contents, indicating the need for re‐certification. Strontium mass fractions in the analysed RMs are high (1500–7000 mg kg−1), and their isotope compositions determined by LA‐MC‐ICP‐MS in the original and the nano‐pellets agree within uncertainty limits.

Section: Resultssupporting

confidence: 89%

“…In addition, in situ Sr isotope ratio measurements were performed using LA‐MC‐ICP‐MS, following the protocol of Weber et al (, ). A Nu Plasma (first generation) MC‐ICP‐MS was coupled to a New Wave UP213 Nd:YAG laser ablation system at MPIC.…”

Section: Analytical Set‐upmentioning

confidence: 99%

Nano‐Powdered Calcium Carbonate Reference Materials: Significant Progress for Microanalysis?

Jochum

Garbe‐Schönberg

Veter

et al. 2019

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“…This results in a maximum Rb/Sr ratio of 0.0002, much lower than the suggested Rb/Sr threshold of 0.02 for successful LA‐(MC‐)ICP‐MS measurements of Sr isotopes (Irrgeher et al ). Further potential interfering elements yielded very low mass fractions (Dy = 0.16 ± 0.04 µg g −1 ; Er = 0.02 ± 0.04 µg g −1 ; Yb = 0.05 ± 0.04 µg g −1 , all uncertainties (2 s ) are for n = 6) and are thus considered to be negligible for in situ Sr isotope measurements, as has been shown for reference materials with a higher mass fraction of these elements (Weber et al ).…”

Section: Resultsmentioning

confidence: 75%

“…Typical carbonate RMs with well‐specified 87 Sr/ 86 Sr ratios, such as JCt‐1, JCp‐1 (both Geological Survey of Japan), FEBS‐1 (National Research Council of Canada, NRCC) and MACS‐3 (U.S. Geological Survey, USGS), have a high‐Sr mass fraction > 1000 µg g −1 (Ohno and Hirata , Yang et al , Jochum et al , Weber et al ) and are therefore mainly suited for in situ analyses of carbonate samples with similar mass fractions (e.g., corals, molluscs and otoliths). USGS MACS‐1 is a low‐Sr carbonate RM with known Sr isotope signature, but the high mass fraction of REEs (especially Dy, Er and Yb) limits its use as an in situ RM due to isobaric interferences of the doubly charged REEs (Weber et al ). Furthermore, not all available RMs show microanalytical homogeneity and potentially need further processing, that is, by milling protocols (Garbe‐Schönberg and Müller ).…”

mentioning

confidence: 99%

NanoSr – A New Carbonate Microanalytical Reference Material for In Situ Strontium Isotope Analysis

Weber

Lugli

Hattendorf

et al. 2019

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The in situ measurement of Sr isotopes in carbonates by MC‐ICP‐MS is limited by the availability of suitable microanalytical reference materials (RMs), which match the samples of interest. Whereas several well‐characterised carbonate reference materials for Sr mass fractions > 1000 µg g−1 are available, there is a lack of well‐characterised carbonate microanalytical RMs with lower Sr mass fractions. Here, we present a new synthetic carbonate nanopowder RM with a Sr mass fraction of ca. 500 µg g−1 suitable for microanalytical Sr isotope research (‘NanoSr’). NanoSr was analysed by both solution‐based and in situ techniques. Element mass fractions were determined using EPMA (Ca mass fraction), as well as laser ablation and solution ICP‐MS in different laboratories. The 87Sr/86Sr ratio was determined by well‐established bulk methods for Sr isotope measurements and is 0.70756 ± 0.00003 (2s). The Sr isotope microhomogeneity of the material was determined by LA‐MC‐ICP‐MS, which resulted in 87Sr/86Sr ratios of 0.70753 ± 0.00007 (2s) and 0.70757 ± 0.00006 (2s), respectively, in agreement with the solution data within uncertainties. Thus, this new reference material is well suited to monitor and correct microanalytical Sr isotope measurements of low‐Sr, low‐REE carbonate samples. NanoSr is available from the corresponding author.

“…Therefore, it is very appropriate that Weber et al . () have determined 87 Sr/ 86 Sr ratios in several existing RMs, particularly focusing on potential use in microanalysis. Samples were analysed by LA‐MC‐ICP‐MS and high‐precision solution MC‐ICP‐MS, and LA‐MC‐ICP‐MS yielded identical 87 Sr/ 86 Sr ratios within uncertainty to the solution analysis.…”

Section: Reference Materialsmentioning

confidence: 99%

GGR Biennial Critical Review: Analytical Developments Since 2014

Linge

Bèdard

Bugoi

et al. 2017

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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 analyses 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