Looking For Cacao In All The Wrong Places: An Analysis Of Maya Pottery With 2-photon Resonance Spectroscopy

Williams , Ann

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https://hdl.handle.net/2142/111508 Copy

Description

Title

Looking For Cacao In All The Wrong Places: An Analysis Of Maya Pottery With 2-photon Resonance Spectroscopy

Author(s)

Williams , Ann

Contributor(s)

DE VRIES, Mattanjah

Issue Date

2021-06-24

Keyword(s)

Spectroscopy as an analytical tool

Abstract

Cacao, a mesoamerican beverage similar to modern hot chocolate, is believed by archaeologists to have been drunk by the ancient Maya elite. Past analysis has often focused on highly decorative vessel forms that were only found in large sites with a social elite. We analyzed common drinking vessels for cacao to question if it was only the socially elite who had access to cacao. Focusing on the region of El Pillar, Belize in the Late Classical Period, we analyzed 35 archaeological sherds from 6 different regions, including sites with and without an elite population. The identification of cacao in ancient pottery sherds is dependent on the presence of the biomarkers theobromine, theophylline, and caffeine. Biomarkers are molecules that exist in high concentrations in the compound of interest, will survive burial, and are unique to that one compound. Samples of pottery are tested for presence of theobromine, theophylline and caffeine and if found to have measurable amounts of theobromine are considered indicative of cacao. Analysis is done by grinding off all outside surfaces to reduce contamination, pulverizing the inner clay matrix, extracting the biomarkers, and concentrating the extractions. These concentrated extractions are then most often analyzed via UPLC-MS. In order to obtain especially high selectivity and low limits of detection, our study utilized the novel technique of resonance enhanced multi-photon Ionization (REMPI) coupled with laser-desorption jet-cooling mass spectrometry. This technique isolates molecules in the cold gas phase where they can be selectively ionized through a two photon resonant process. We found evidence of cacao in samples from sites both with and without an elite.

Publisher

International Symposium on Molecular Spectroscopy

Type of Resource

Text

Language

eng

Permalink

http://hdl.handle.net/2142/111508

DOI

10.15278/isms.2021.RF06

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