Non-destructive identification of prehistoric adhesives by HS-GC×GC-TOFMS (Anika Lokker, MDCW 2023)

• 🎤 Presenter: Anika Lokker¹, Pierre-Hugues Stefanuto², Ronè Oberholtzer², Dries Cnuts², Veerle Rots², Jean-François Focant² (¹University of liège, liège, Belgium. ²University of liège, Liège, Belgium)

Abstract

Identification of prehistoric adhesives on stone tools is valuable as it might reveal something about tool use and human behaviour. Currently, prehistoric glues are chemically analysed by gas chromatography coupled to mass spectrometer (GC-MS) which requires extraction and derivatization of the residues¹.

This is a major drawback as it is destructive for the glue and often, the required amount is not present. Moreover, the adhesives cover a wide range of materials (e.g., resin,animal glue, gum). Therefore, sensitive, universal, and non-destructive identification methods are needed. Headspace solid phase micro-extraction (HS-SPME) in combination with GC-MS and with comprehensive GC-time-of-flight mass spectrometer (HS-SPME-GCxGC-TOFMS) has been proposed²´³.

HS-SPME requires no extraction and derivatization, it is therefore a good opportunity for the chemical identification of prehistoric glues. Moreover, GCxGC-TOFMS has more peak capacity and is more sensitive than GC-MS³. But sensitivity remains a problem, therefore we investigated a different headspace method; dynamic headspace (DHS) coupled to GCxGC-TOFMS.

The DHS method is optimized and validated via design of experiment on pine resin and hide glue. Subsequently, the method is tested on several different adhesives and compared to SPME-GCxGC-TOFMS.

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