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).

The fast and accurate on-site analysis of brines and ore leaching solutions is still a challenge. Conventionally used laboratory methods such as ICP-OES or ICP-MS are not suitable for on-site applications due to high plasma gas flow rates and power consumption. On the other hand, portable X-ray spectrometers are not able to analyse light elements such as Li, Na or K with adequate accuracy. Therefore, a fast and precise method combining on-site suitability and quantification of light elements would be preferable.

Here we investigated the potential of the Micro-Discharge Optical Emission Spectroscopy (µDOES) for the on-site and on-line analysis of lithium ore leaching solutions, whose industrial end product is an essential precursor for the battery industry. The technology is based on a micro-plasma, which is directly created inside the liquid sample without any carrier gas by applying high voltage pulses to electrodes enabling optical emission spectroscopy on-site^[1].

After parameter optimisation (conductivity, wavelength selection, discharge energy), on-line measurements of different process steps at a lithium hydroxide pilot plant were carried out. In addition to Li, other elements like Na, K, Ca, Mg or Rb were quantified. The technique demonstrated its capability for the fast and precise on-site analysis of major components and trace elements in saline solutions. Results showed good agreement with established laboratory methods, such as ICP-OES and ion chromatography.

[1] B. Wiggershaus, M. Jeskanen, A. Roos, C. Vogt and T. Laurila, Trace element analysis

in lithium matrices using Micro-Discharge Optical Emission Spectroscopy, J. Anal. At.
Spectrom., 2024. DOI:10.1039/D4JA00044G.

The purpose of this study was to investigate the chemical composition of red iron pigments based on waste iron sulfate. As a model waste, waste iron(II) sulfate from Grupa Azoty Zakłady Chemiczne POLICE S.A is used. Obtained pigments were also compared to commercially available materials from various manufacturers like BASF (Germany), Percheza (Czech Republic), Boruta-Zachem (Poland) or Edan (Poland).

Pigments were analyzed with several analytical methods like: X-Ray Diffraction, Dynamic Light Scattering, X-ray photoelectron spectroscopy, Fourier-transform infrared spectroscopy, Helium Ion Microscopy and Scanning Electron Microscopy.

In determining the phase and chemical composition, we encounter some limitations of the methods. For example, during XRD analysis using Cu-Kα source, quartz-derived phases were visible in some commercial pigments. Comparing these results with FTIR analysis, the presence of quartz was confirmed, but in addition, vibrations from CaCO₃ were seen, which was not visible in XRD. Only by changing the radiation source in XRD to Co-Kα was it possible to detect phases originating from CaCO₃.

Precise knowledge of the contents of samples is frequently lacking prior to analysis. This is particularly true for external samples, which are frequently examined without prior information. Consequently, it is crucial to combine various analyses to obtain the most accurate results.