Extended Data Fig. 8: Lu isotope fractionation induced by Ln resin chromatography.
From: Late fluid flow in a primitive asteroid revealed by Lu–Hf isotopes in Ryugu
(a) Elution profile for Lu during the isotope fractionation experiment using the SPEX Lu standard solution. (b) Isotope composition of eluted Lu represented as δ176Lu with respect to the unprocessed standard. Open symbols represent data for individual elution fractions, whereas solid symbols show those for the cumulative elution fractions. Error bars plotted on δ176Lu for individual fractions represent the 2 s.e. internal precisions. Grey band expresses the 2 s.d. external reproducibility of analyses (n = 14) of the unprocessed standard. Elution fractions are as follow: 3.3-(i), the first elution with 14 mL of 3.3 M HCl; 3.3-(ii), the second elution with 4 mL of 3.3 M HCl; 6-(i) to 6-(V), the following successive elution sections with 0.5 mL of 6 M HCl; and 6-(vi), the last fraction eluted between 2.5 and 4.5 mL of 6 M HCl. The δ176Lu values changed from negative at early elution stages to positive at late elution stages. The observed variation is comparable to analytical uncertainties for Ryugu samples and an order of magnitude smaller than required to account for the observed 176Hf excesses by accelerated 176Lu decay.
