Stable cerium isotope analysis of geological materials by MC-ICP-MS

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

“…Stable Ce and Nd isotope fractionation factors on the α-HIBA column were quantified in this study, providing a necessary framework that allows for assessment of possible influence of incomplete yield from our column on stable Ce and Nd isotope analysis. Column-induced stable Ce isotope fractionation has been quantified for chromatographic methods using LN and DGA resin, 51,71,72 but it has never been quantified for the α-HIBA column. Stable Nd isotope fractionation during the α-HIBA chemistry has been studied; 69 a ∼1.40‰ difference in δ 146 Nd was observed between the head and tail of the Nd elution peak, with heavier Nd isotopes being eluted first relative to lighter isotopes.…”

“…Although different columns and elution protocols were developed in this and previous studies, column-induced Ce and Nd isotope enrichment factors are broadly comparable among different separation methods using LN resin and the α-HIBA chemistry. 51,69 Despite the high cost, the method based on DGA resin 71,76,77 produces the smallest Ce and Nd isotope fractionations (Fig. 3), thereby is more resistant to potential Ce and Nd loss from the column.…”

“…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.…”

Simultaneously obtaining stable and radiogenic Nd isotope ratios through a single DGA column using double spike TIMS

“…39 During eluting REEs, LN resins are typically loaded in dilute acid and stripped with more concentrated acid, 17 while DGA resins are loaded in more concentrated acid and stripped with dilute HCl. 40–42 The AG 50W-X8 resin is a strong cation exchanger with sulfonic acid functional groups attached to a styrene divinylbenzene copolymer lattice. Li et al 43 reported REEs behavior using AG50W-X8 with α-HIBA and observed that the distribution coefficients ( K d ) of heavy REEs are lower than light REEs, contrary to that of DGA resin.…”