Identifying the Unknown Content of an Ancient Egyptian Sealed Alabaster Vase from Kha and Merit's Tomb Using Multiple Techniques and Multicomponent Sample Analysis in an Interdisciplinary Applied Chemistry Course

Abstract

This article highlights the multianalytical study of exuded liquid from an ancient Egyptian sealed alabaster vase by Master's students in an applied chemistry for cultural heritage course. Master students are introduced to the field of Archaeometry that see the collaboration of experts in different areas of research such as conservators, curators of museums, physicists, chemists, etc. The sample is a residue exuded on the linen strip sealing an ancient Egyptian alabaster vase (inventory number S.8448) from the collection of the Museo Egizio in Turin (Italy). The students start to plan the noninvasive investigation by X-ray fluorescence (XRF), transmission electron microscopy (TEM), and energy-dispersive X-ray spectroscopy (EDS) for the inorganic compounds characterization, followed by the extraction of the organic components (such as oils, fats, and waxes) to be analyzed by high-resolution 1H and 13C nuclear magnetic resonance (NMR) spectroscopy and 2D NMR correlation spectroscopy (COSY), heteronuclear single quantum coherence (HSQC), and long-range heteronuclear correlation (HMBC) techniques and by gas chromatography coupled with mass spectrometry (GC/MS). Reference standards, spectral databases, and published data on similar artifacts served as the basis for the interpretation of the instrumental results. The approach was introduced in the course of Applied Chemistry for Cultural Heritage for Master students in Archaeology (University of Palermo, Italy), where the need is to know how to approach the scientific investigation together with the conservation scientists and how to manage with a very low amount of sample. Pedagogically, the approach introduces students to the main techniques currently used in the field of Archaeometry while reinforcing fundamental concepts in sample collecting and multicomponent microsample analysis. This interdisciplinary approach provides a unique experience that demonstrates chemistry's broad applicability outside of the traditional laboratory. Students are guided to identify the inorganic and organic components of the exudate liquid: the first one is ascribable to clay minerals iron oxides, which could impart the brown color to the sample; the second one is ascribed to triglycerides of various kinds, which probably comes from vegetable oil.