Stable neodymium isotopic fractionation during chemical weathering

Sequential separation of cerium (Ce) and neodymium (Nd) in geological samples for high-precision analysis of stable Ce isotopes, and stable and radiogenic Nd isotopes by MC-ICP-MS

“…The simple sample–standard bracketing (SSB) method 78,79 and the combined sample–standard bracketing and internal normalization (C-SSBIN) method 80,81 are two methods commonly used to correct for instrumental mass bias during stable isotope analysis on MC-ICP-MS. The C-SSBIN method has been applied to the analysis of stable Ce isotopes (with Sm-doping) 37–41,51,52,67,71,76,82 and stable Nd isotopes (with Eu-doping), 46,51,52,83,84 whereas the simple SSB method has also been adopted by some studies for stable Nd isotope analysis. 47,72,85,86 Compared to the simple SSB method, the C-SSBIN method requires addition of a dopant element in each sample and the bracketing standard for the measurement, so it is more labor-intensive and accompanied by a higher risk of sample contamination.…”

“…High-temperature magmatic processes, such as partial melting, typically do not produce resolvable stable Nd isotope fractionation, 44,45 but systematic variations of stable Nd isotopes have been observed in a weathering profile, possibly caused by isotopic fractionation during Nd adsorption/desorption on different mineral surfaces. 46 Stable Nd isotopes have also shown potential in elucidating sediment provenance 47 and petrogenesis. 48,49 A combined use of stable Ce and Nd isotopes is anticipated to multiply the information that a single isotope system can offer, considering overall similar chemical behavior of the two elements but for their distinct redox properties.…”

Determination of Rare Earth Element Isotopic Compositions Using Sample-Standard Bracketing and Double-Spike Approaches

“…There has been a growing interest in stable isotope analyses of rare earth elements (REEs), including Ce, ,,,,− ,− Nd, ,,− ,,,− ,− Sm, ,, Eu, ,,− Gd, Dy, Er, , and Yb. , …”

“…The carbonate CCH-1 analyzed in this study also shows heavy Nd isotopes (0.071‰/amu). Bai et al 32 also reported fractionated Nd isotopes in a basaltic soil profile on Hainan Island, South China, spanning ∼0.105‰/amu. Overall, Nd isotope fractionation is relatively limited and occurs mostly in low-temperature processes such as adsorption/precipitation and chemical weathering or controlled by kinetic processes.…”

“…Expanding the database of REE stable isotopic fractionation by investigating extraterrestrial samples, low-temperature samples, and high-temperature samples influenced by NFS and kinetic effects would improve our understanding of the geochemical behavior of REEs in diverse environments. Reported REE isotope fractionations are still relatively limited (Ce, ,, Nd, ,− Sm, ,, Eu, ,,− Gd, Dy, Er, , and Yb , ), with most publications focused on developing analytical methods for one or two REEs, and the samples analyzed are primarily geostandards and igneous rocks.…”