The wide range of chemical and isotopic signatures preserved in minerals of the apatite supergroup makes them truly useful across a broad spectrum of scientific applications, helping geoscientists to understand magmatic, metamorphic, paleoenvironmental, and (paleo)ecological processes. Ongoing progress in method developments has made secondary ion mass spectrometry (SIMS) one of the primary techniques for micro-scale apatite investigations. The ability to sample in situ picogram masses with SIMS allows for isotope studies of both rare and heterogenous samples. However, the availability and quality of reference materials (RMs) necessary for quantitative measurements has hobbled key applications.
Improvements of apatite isotope analysis method have been a major focus of our nearly decade-long initiative [1,2]. We are continuing our efforts to characterize RMs and advance SIMS measurement methodologies for sulfur, boron, oxygen, and U-Pb isotopes in apatite and related materials. By making use of existing mineral collections, we have been investigating the chemistry-dependent behavior of different samples under primary ion beams, along with the surface properties of polished mounts and calibration strategies. Such improvements in our fundamental understanding of these analyses will be crucial for future apatite research initiatives. Characterization studies devoted to the coming generation of apatite RMs have documented the challenges faced even by more traditional analytical techniques operating at much larger sampling scales.
References:
[1] Wudarska et al. (2021), Geostand Geoanal Res. doi:10.1111/ggr.12366.
[2] Wudarska et al. (2022), Geostand Geoanal Res. doi:10.1111/ggr.12416.
Acknowledgements: This research has been supported by the International Association of Geoanalysts (Geoanalytical Research and Networking Grants).