Background: Determining the composition of artifact residues is a central problem in ancient residue metabolomics. This is done by comparing mass spectral features in common with an experimental artifact and an ancient artifact (standard method). While this method is simple and straightforward, we sought to increase the accuracy of predicting which plant species had been used in which artifacts.

Results: Here, we introduce an algorithm (new method) based on ideas from the field of natural language processing (NLP) to solve this problem. We tested our strategy on a set of modern clay pipes. To limit biases, we were not provided information on which plant species had been smoked in which clay pipes. The results indicate that our new method performed 12.5% better than the standard method in predicting the plant species smoked in each artifact.

Conclusions: Utilizing an NLP-based approach, we developed a robust algorithm for characterizing the composition of artifact residues. This work also discusses other general applications in which our algorithm could be used in the field of metabolomics, such as datasets where there are a limited number of replicates.