16
views
0
recommends
+1 Recommend
0 collections
    0
    shares
      • Record: found
      • Abstract: found
      • Article: not found

      Ultra-high-precision Nd-isotope measurements of geological materials by MC-ICPMS

      Read this article at

      ScienceOpenPublisherPMC
      Bookmark
          There is no author summary for this article yet. Authors can add summaries to their articles on ScienceOpen to make them more accessible to a non-specialist audience.

          Abstract

          We report novel techniques allowing the measurement of Nd-isotope ratios with unprecedented accuracy and precision by multi-collector inductively coupled plasma mass spectrometry.

          Abstract

          We report novel techniques allowing the measurement of Nd-isotope ratios with unprecedented accuracy and precision by multi-collector inductively coupled plasma mass spectrometry. Using the new protocol, we have measured the Nd-isotopic composition of rock and synthetic Nd standards as well as that of the Allende carbonaceous chondrite. Analyses of BCR-2, BHVO-2 and GSP-2 rock standards yield mass-independent compositions identical to the JNdi-1 Nd-reference standard, with an external reproducibility of 2.4, 1.6, 1.6 and 3.5 ppm respectively, on μ 142Nd, μ 145Nd, μ 146Nd and μ 150Nd (μ representing the ppm-deviation of the ratios from JNdi-1) using 148Nd/ 144Nd for internal normalization. This represents an improvement in precision by a factor of 2, 7 and 9 respectively for μ 142Nd, μ 145Nd and μ 150Nd. Near-quantitative recovery from purification chemistry and sample-standard bracketing allow for the determination of mass-dependent Nd-isotopic composition of samples. Synthetic standards, namely La Jolla and AMES, record mass-dependent variability of up to 1.2 ε per atomic mass unit and mass-independent compositions resolvable by up to 3 ppm for μ 142Nd and 8 ppm for μ 150Nd, relative to JNdi-1. The mass-independent compositions are consistent with equilibrium mass fractionation during purification. The terrestrial rock standards define a uniform stable ε 145Nd of −0.24 ± 0.19 (2SD) relative to JNdi-1, indistinguishable from the mean Allende ε 145Nd of −0.19 ± 0.09. We consider this value to represent the mass-dependent Nd-isotope composition of Bulk Silicate Earth (BSE). The modest mass-dependent fractionation of JNdi-1 relative to BSE results in potential effects on mass-independent composition that cannot be resolved within the reproducibility of our analyses when correcting for natural and instrumental mass fractionation by kinetic law, making it a suitable reference standard for analysis of unknowns. Analysis of Allende (CV3) carbonaceous chondrite returns an average μ 142Nd deficit of −30.1 ± 3.7 ppm in agreement with previous studies. The apparent deficit is, however, lowered to −23.8 ± 4.0 ppm while normalizing to 148Nd/ 144Nd instead of 146Nd/ 144Nd. We interpret this as the effect of a possible nucleosynthetic anomaly of –6.3 ± 0.5 ppm in μ 146Nd. As 142Nd and 146Nd are both s-process-dominated nuclides, this hints at the possibility that terrestrial μ 142Nd excess may not reflect 146Sm decay as widely accepted.

          Related collections

          Most cited references60

          • Record: found
          • Abstract: not found
          • Article: not found

          Precise determination of SmNd ratios, Sm and Nd isotopic abundances in standard solutions

            Bookmark
            • Record: found
            • Abstract: found
            • Article: not found

            142Nd evidence for early (>4.53 Ga) global differentiation of the silicate Earth.

            New high-precision samarium-neodymium isotopic data for chondritic meteorites show that their 142Nd/144Nd ratio is 20 parts per million lower than that of most terrestrial rocks. This difference indicates that most (70 to 95%) of Earth's mantle is compositionally similar to the incompatible element-depleted source of mid-ocean ridge basalts, possibly as a result of a global differentiation 4.53 billion years ago (Ga), within 30 million years of Earth's formation. The complementary enriched reservoir has never been sampled and is probably located at the base of the mantle. These data influence models of Earth's compositional structure and require revision of the timing of global differentiation on Earth's Moon and Mars.
              Bookmark
              • Record: found
              • Abstract: not found
              • Article: not found

              A consistent set of nuclear rms charge radii: properties of the radius surface R(N,Z)

                Bookmark

                Author and article information

                Journal
                JASPE2
                Journal of Analytical Atomic Spectrometry
                J. Anal. At. Spectrom.
                Royal Society of Chemistry (RSC)
                0267-9477
                1364-5544
                2016
                2016
                : 31
                : 7
                : 1490-1504
                Affiliations
                [1 ]Centre for Star and Planet Formation
                [2 ]Natural History Museum of Denmark
                [3 ]University of Copenhagen
                [4 ]Copenhagen
                [5 ]Denmark
                Article
                10.1039/C6JA00064A
                4946631
                27429505
                ade1eb11-29fd-4e3d-8b90-a92077a736e6
                © 2016
                History

                Comments

                Comment on this article

                scite_
                65
                3
                53
                0
                Smart Citations
                65
                3
                53
                0
                Citing PublicationsSupportingMentioningContrasting
                View Citations

                See how this article has been cited at scite.ai

                scite shows how a scientific paper has been cited by providing the context of the citation, a classification describing whether it supports, mentions, or contrasts the cited claim, and a label indicating in which section the citation was made.

                Similar content13

                Cited by11

                Most referenced authors536