Message in an Ancient Bottle
GC-MS uncovers the mystery contents of Bronze Age ceramic bottles
Gas chromatography-mass spectrometry (GC-MS) analysis of organic residues in ceramic bottles appear to have revealed an ancient trade in scented oils as long ago as the 3rd millennium BCE (1). The ceramic bottles, excavated from an archaeological site in Turkey, were suspected to have contained liquid, but no researchers had analyzed the residues inside them – until now!
GC-MS identified compounds in the bottles that suggest scented oils, providing the oldest evidence for trade in such commodities in the region. To learn more about the findings – which highlight the importance of GC-MS in archaeological investigations – we spoke with the study’s lead author, Ismail Tarhan, Associate Professor of Biochemistry at Selçuk University, Turkey.
What was the inspiration for this work?
Archaeology has always been fascinating to me, and my interest was further fueled by a meeting with an archaeologist around five years ago. The thought of continuing my professional chemistry career in the field of archaeology was very exciting – so I started archaeometric studies, examining archaeological artifacts with science.
To begin with, I focused on the production conditions of open-mouthed ceramic artifacts, before intensifying my research to find an answer to a burning question: what was consumed or stored in these containers? Through trial and error of various analytical techniques, I managed to detect the degradation of food products within the containers.
What method was used for the analysis?
Ceramic artifacts have a mostly porous structure – allowing organic biomolecules to stay preserved inside. We analyzed the invisible micro-compounds in the inner walls of the ceramic and extracted the organic residues remaining in the pores of the ceramic structure into a liquid solvent. By putting this liquid through our GC-MS device, we detected organic residue molecules that showed what could have been held within each ceramic container.
What were your findings?
We discovered the presence of various traces of liquids from within each ceramic container, alongside dicarboxylic and oleic acids with large samples of palmitic acids. These substances suggest that a plant-based oil was contained frequently in these bottles. Furthermore, the presence of diterpenoids suggests the addition of ingredients such as conifer resin and other plant derived products. This leads us to conclude that the containers were used for scented oils.
Overall, we can determine that scented oils were exchanged in Anatolia, Turkey during the late 3rd millennium BCE. The different organic residues also indicate that a range of different recipes were used and contained within the containers for an undisclosed period of time.
Were you surprised by the results of your study?
We were surprised to learn that scented oils were highly prominent in the analyzed ceramics. We knew from archeological data that there was a high probability of finding traces of valuable herbal products, as opposed to products in daily consumption. However, it was a pleasant surprise to find similar results from organic residue analysis.
Are there any plans for future research?
There are many studies we would like to conduct as an extension of this research. Firstly, we plan to consolidate the results of GC-MS analysis with the results of stable isotope analysis alongside colleagues in Europe. Additionally, we’ve received many offers since publishing our study to conduct similar research with different excavations. We hope that exploring these avenues allows for more comprehensive analysis into our ancestors' livelihoods.
- I Tarhan et al., Toward an understanding of the exchange in ancient scented oils through organic residue analysis of Bronze Age Near Eastern ceramic bottles by GC-MS (2023). DOI: 10.1111/arcm.12852.
Associate Editor, The Analytical Scientist