3,2,1- 1Johannes Gutenberg University, Department Chemie, AK Hoffmann, Mainz, Germany (sjohann@uni-mainz.de)
- 2School of Geography and Natural Sciences, Faculty of Engineering and Environment, Northumbria University, United Kingdom
- 3Université de Rouen, Mont-Saint-Aignan, France
Speleothems represent important paleoenvironmental archives that can record environmental changes over thousands of years and can be dated reliably using the 230Th/U method. The relatively closed and chemically stable cave environment favours the preservation of organic compounds in addition to commonly used proxies such as stable isotopes and trace elements. [1,2]
Sterols are of particular interest as organic biomarkers because they are stable under low-oxygen conditions and originate from different sources, including plants, animals, and microbial processes. Cholesterol and sitosterol, derived mainly from animals and plants, respectively, can be transformed by microbial activity into stanols, which are often linked to faecal inputs. Coprostanol is especially relevant as an indicator of human activity, as it is a dominant stanol in human faeces. While sterol-based biomarkers are widely applied in soil and sediment studies, their use in speleothem research is still limited. This is mainly due to the complex carbonate matrix of speleothems and the generally low concentrations of organic compounds. A simple ultrasonic bath extraction was demonstrated to be an efficient and highly reproducible method for sterol recovery. Subsequent analysis was carried out using high-performance liquid chromatography coupled to atmospheric pressure chemical ionization high-resolution Orbitrap mass spectrometry (HPLC-APCI-HRMS), offering excellent sensitivity and mass resolution.
This analytical strategy significantly improves the extraction and detection of sterols in speleothems and provides a robust framework for extending their application in paleoenvironmental and anthropogenic reconstructions. As a proof of principle, sterol compositions were analysed in speleothems from diverse geographical regions, including Germany, Vietnam, France and Lebanon.
[1] A. Blyth et al. Quat. Sci. Rev. 149 (2016) 1-17. [2] J. Homann et al. Biogeosciences. 20 (2023) 3249–3260.
How to cite: Schäfer, J., Snowling, C., Nehme, C., Breitenbach, S., and Hoffmann, T.: Sterol Biomarkers as Indicators of Environmental Change and Anthropogenic Signals in Speleothem Records, EGU General Assembly 2026, Vienna, Austria, 3–8 May 2026, EGU26-7934, https://doi.org/10.5194/egusphere-egu26-7934, 2026.
