The bioarchaeology of tobacco use: An exploratory study of nicotine and cotinine detection in tooth dentine

Tobacco use has been evident in human populations throughout history. However, the detection of tobacco usage through the presence of metabolites, such as, nicotine and cotinine, in human skeletal remains is challenging due to the breakdown and loss of these molecules over time. This research attempts to detect tobacco use from dentine in skeletal remains from an archaeological context. Adapting a previously published untargeted method (Badillo-Sanchez et al., 2023b) to a targeted approach for analysing dentine, eight tooth dentine samples were extracted from five skeletons excavated from a Napoleonic battlefield (1809) in Austria. All five individuals had external signs of tobacco use (e.g., pipe facets and tobacco staining). Modern dentine samples from tobacco smokers and archaeological samples from the pre-tobacco period (6th-9th century) in Europe were also tested as negative and positive controls, respectively. After extraction and purification, the extracts were analysed using a liquid chromatography system directly coupled to a tandem mass spectrometer. Nicotine was not detected in any of the archaeological teeth. Difficulties of nicotine detection above the signal-to-noise levels were also seen in one of the positive control samples and could be linked to the half-life of nicotine in the body. On the other hand, cotinine was identified in one of the five samples from the early 19th century and in all three modern control samples.

This indicates that tooth dentine is a reliable source for archaeometabolomic studies, and cotinine can be a targeted metabolite in investigations of tobacco use in the past.