XANES reference library of sulphur-containing compounds for biological research: a status report from the ASTRA beamline at the SOLARIS National Synchrotron Radiation Centre.

Sulphur is present in a vast multitude of biological compounds, and X-ray absorption spectroscopy (XAS) is a powerful and well-established characterization technique to study the local atomic environment of this chemical element in such systems in detail, with a high potential for advancing knowledge in medicine, biotechnology and environmental research. For this project, X-ray absorption near edge structure (XANES) spectroscopy at the sulphur K-absorption edge was used to investigate sulphur-containing compounds of biological interest at the ASTRA beamline (SOLARIS National Synchrotron Radiation Centre, Kraków, Poland). XANES provides valuable insights into the bonding environment of sulphur and thereby contributes to a deeper understanding of the structural characteristics and functional roles of sulphur in biological systems. The ASTRA beamline, specifically optimized for XAS in the tender energy range, offers ideal conditions for further research in this field, enabling detailed analysis of the composition and changes in sulphur containing compounds.