Description
Kinetic and equilibrium isotope effects make subtly different predictions about the massdependent scaling between the silicon (Si) isotope ratios 30Si/28Si and 29Si/28Si. The massdependencies of kinetic vs. equilibrium fractionations are typically not resolvably different during analysis, but recent work [1,2] demonstrates that with high-precision, high-resolution analyses deviations from a fractionation line are in fact quantifiable. This opens up a new analytical frontier of ‘triple silicon isotopes’ that can build on frameworks developed for e.g. the oxygen and sulfur isotope systems, to provide a new constraint on Si sources and processing. Here we present the results of preliminary experiments designed to capture a transition from kinetic to equilibrium fractionation during amorphous silica precipitation. Using educt-product (rather than standard-sample) bracketing on a Neptune HR-MC-ICPMS, we investigate optimal measurement strategies for improved precision of triple silicon isotopes. We also present evidence for mass-independent silicon isotope fractionation duringMC-ICP-MS analyses, and discuss the extent to which this might confound measurement and interpretation of triple silicon isotopes.
| Period | 29 May 2024 → 31 May 2024 |
|---|---|
| Event title | Isotopen in Biogenic Silica |
| Event type | Conference |
| Location | Louvain-La-Neuve, BelgiumShow on map |
| Degree of Recognition | International |