Optimization of Dynamic Headspace Sampling Conditions for the Identification of Paleolithic Adhesives

Abstract

The characterization of Paleolithic adhesives holds great potential for understanding human behavior and its evolution. Gas chromatography–mass spectrometry (GC–MS) is the most accurate identification method; unfortunately, it is destructive and requires a large sample size. Hence, most Paleolithic adhesives are not characterized with GC–MS. Here, a new nondestructive identification method is introduced; dynamic headspace (DHS) with two‐dimensional GC coupled to a time‐of‐flight MS. The DHS extraction is optimized with an experimental design approach. Four parameters were selected, and the optimized values were as follows: incubation temperature: 50°C, incubation time: 20 min, purge volume: 450 mL, and purge flow: 22.5 mL min−1, pine resin was chosen as a proxy for Paleolithic adhesives. Subsequently, DHS was also tested on hide glue, which has less volatile than pine resin, and the universality of the extraction was tested. With untargeted techniques, a distinction between hide glue and pine resin could be made based on their chromatographic profiles. Lastly, DHS was tested against an existing HS‐solid‐phase microextraction method. DHS showed a higher response in the total area of the chemical groups of interest. Thus, DHS has a higher sensitivity for prehistoric adhesives than solid‐phase microextraction, which is desired for minimal samples.