• Abstract and Figures
• Public Full-text

Eur. Phys. J. Plus (2021) 136:661 https://doi.org/10.1140/epjp/s13360-021-01627-1 Regular Article Chemical composition overview on two organic residues from the inner part of an archaeological bronze vessel from Cumae (Italy) by GC–MS and FTICR MS analyses Jasmine Hertzog1,2,a , Hitomi Fujii3,b , Andrea Babbi4,5,6 , Agnès Lattuati-Derieux3,7, Philippe Schmitt-Kopplin1,2 1 Analytical Food Chemistry, TUM Technische Universität München, 85354 Freising, Germany 2 Analytical BioGeoChemistry, Helmholtz Zentrum Muenchen, 85764 Oberschleisheim, Germany 3 Research Department, Centre de Recherche et de Restauration des Musées de France, C2RMF, Ministère de la Culture, 14 quai François Mitterrand, 75001 Paris, France 4 Istituto di Scienze del Patrimonio Culturale del Consiglio Nazionale delle Ricerche, Monterotondo St., 00015 Roma, Italy 5 Graduiertenkolleg 1876 ”Frühe Konzepte von Mensch und Natur”, Institut Für Altertumswissenschaften/Ägyptologie, Johannes Gutenberg-Universität Mainz, 55122 Mainz, Germany 6 Leibniz-Forschungsinstitut Für Archäologie des Römisch-Germanischen Zentralmuseums (RGZM), 55116 Mainz, Germany 7 CNRS – IRCP, Chimie-ParisTech, Institut de Recherche de Chimie-Paris, PSL University, 11 rue Pierre et Marie Curie, 75005 Paris, France Received: 11 October 2020 / Accepted: 31 May 2021 © The Author(s), under exclusive licence to Società Italiana di Fisica and Springer-Verlag GmbH Germany, part of Springer Nature 2021 Abstract A bronze vessel, containing solid black material, was found in a grave dated to the late eighth century BC and located in the Middle Tyrrhenian region. Two residue samples of this black material were subject to molecular characterization in order to assess first its composition and then the function of this precious object. Two different technique analy- ses, namely gas chromatography–mass spectrometry (GC–MS) and electrospray ionization Fourier transform ion cyclotron resonance mass spectrometry, in negative-ion mode (ESI(−) FTICR MS), were employed in that way. If GC–MS analysis is commonly used for the char- acterization of archaeological samples by identifying biomarkers related to organic material, FTICR MS was used to achieve a fast global molecular description with up to thousands of assignments. In addition, this technique enabled to hypothesize about the different materials involved in the black material composition. As a result, lipids, beeswax, conifer resin, and pitch from birch bark were supposed, which was thereafter confirmed by GC–MS. Conse- quently, FTICR MS can be regarded as an efficient tool for the fast profiling of the organic archaeological compounds. 1 Introduction Composition characterization of archaeological samples is essential to increase our knowl- edge of ancient civilizations regarding their cultural habits, the contemporary trade routes a e-mail: [email protected] (corresponding author) b e-mail: [email protected] (corresponding author) 0123456789().: V,-vol 123 661 Page 2 of 22 Eur. Phys. J. Plus (2021) 136:661 allowing importing specific materials, or the status of the buried person. Up to now, one of the preferred analytical methods is gas chromatography coupled to mass spectrometry (GC–MS) [1]. This technique is generally performed to achieve the molecular characteri- zation of archaeological samples by identifying archaeological organic biomarkers that are directly related to a specific substance. For instance, abietic acid derivatives and betulin derivatives are, respectively, related to pine resin and pitch from birchbark [2, 3]. Another and less common technique in the field of archaeometry was employed, namely Fourier transform ion cyclotron resonance mass spectrometry with electrospray ionization, in negative-ion mode (ESI(−) FTICR MS). This non-targeted approach requires a high- resolution mass spectrometer in order to acquire mass spectra of thousands features, which are assigned with a unique molecular formula thanks to the high-mass accuracy. The previous works reported on the study of archaeological samples by FTICR MS are essentially focused on one biochemical class such as lipids or proteins [4–6]. To obtain a global view of the sample composition, the thousands of assignments are plotted according to their hydrogen-to-carbon versus oxygen-to-carbon ratios to generate a van Krevelen diagram [7, 8]. Depending on the plot location on the diagram, it is possible to distinguish fatty acids, terpenoids or sugars. Furthermore, comparison of molecular formula of achieved assignments with those of known archaeological biomarkers can be performed for putative assignments [9, 10]. In fact, as no structural information can be obtained by FTICR MS, only putative species can be attributed to a MS signal based on their molecular formula. However, these candidate compounds are assigned based on our knowledge on the organic composition of archaeological material [10, 11]. Thus, based on these candidates, hypotheses can be done on the used material. This study is focused on two black material residue samples, Tb104-1 and Tb104-2, from within a bronze vessel dating to the late eighth century BC (Fig. 1). In order to determine its chemical composition, these two analyses were performed. The obtained assumed chemical compounds by EST FTICR MS are then compared to GC–MS results. 2 Archaeological context Grave Artiaco 104 represents a key context of the beginning of the Early Orientalizing Period in the Middle Tyrrhenian region (ca 730–680 BC). This burial was uncovered by accident in Don Alfonso Artiaco’s field about 100 m N of the NE Gate of the historical defensive walls of Cumae (Naples) on 27 March 1902 (Fig. 2). Actually, the digging activities which led to the discovery of the grave aimed mainly to free the majestic tholos tomb of the Sannitic era (fourth century BC) from the earth which had already been turned to light on 7 February [12–17]. Grave 104, a male cremation placed in a large rectangular tufa-stone container, was not the only burial in the Artiaco field. Actually, two inhumations with wooden coffins turned up in the area surrounding the tholos tomb. It is the case of graves 103bis and 111 that are almost concurrent with the context of 104 (104: end of the eighth century BC; 103bis, 111: end of the eighth century, early seventh century BC) and can be paralleled to it for both, the depth and the orientation (104: NE–SW; 103bis, 111: E–W) [12]. These tantalizing similarities lend weight to the hypothesis of a funerary cluster, possibly kin-based [14]. Nonetheless, the differences in the burial structure, ritual, and particularly in the wealth and composition of the grave-goods, point to an unequivocal difference in social status. In fact, if the cremated male individual was buried with an extremely rich, varied, and quite exotic 123 Eur. Phys. J. Plus (2021) 136:661 Page 3 of 22 661 Fig. 1 Pictures of the bronze vessel (a) from the Grave 104 Artiaco, vessel residues (b), and studied black material (c). Pictures from Andrea Babbi Fig. 2 Location of Cumae. Map from Andrea Babbi inventory clearly echoing the privileged and almost unique social status of the deceased, the two inhumed female individuals had been offered a much simpler assemblage furnished with vases displaying either an ‘Aegean’ or a local pedigree. Grave Artiaco 104 comprised a large and deep quadrangular pit (2.20×2.10×4.0 m), at the centre of which a monolithic rectangular tufa-stone container with a lid made up of two tufa slabs had been laid on a layer of fern leaves covering the bedrock. Before commenting on the burial accoutrements, it must be underlined that the inventory could be incomplete 123 661 Page 4 of 22 Eur. Phys. J. Plus (2021) 136:661 due to the accidental and partial removal of one side of the pit that led to the discovery of the grave itself [12]. Within the lithic container and at its centre, there was a Chinese boxes sequence of sorts consisting of metal containers: a silver urn buried in a slightly flattened bronze cauldron which in turn had been laid within a larger globular bronze one, and that again had been covered by a large, richly decorated, bronze shield made of very thin metal foil. A varied set made up of gold and silver jewels and vases for drinking and possibly offering had been buried outside and around the globular cauldron, i.e. around the deceased. This location and the fact that all these offerings had been originally laid on the funeral pyre, as hinted at by the clear signs of exposure to fire, make it possible to interpret them as belonging of the deceased and the space itself as a sort of ‘private’ area/dimension. Outside the container, therefore in a sort of ‘public’ area because more accessible and ’visible’ than the previous one, the funerary offerings laid on the fern leaves likely conveyed and displayed distinctive social traits of the deceased due to their connection with the accom- plishment of specific practices [12, 17]. Along the south-east side, there was a cluster of iron objects, mainly weaponry (e.g. swords and spears), but also two horse bits and a few remnants possibly of a chariot, as well as a set of quite large spits. At the east corner of the lithic container, the occurrence of pottery fragments usually referred to as stemming from a large amphora with an ‘Aegean’ aura (‘SOS’ type) [12] was recorded. Along the short north- eastern side two rather thick bronze discs, recently interpreted as a pair of pans belonging to a balance scale, likely used for weighing not only small amounts of precious metals, but also larger quantities of raw materials (e.g. amber, bronze, and lead) [14], were found. Finally, two small cauldrons with lotus flower-shaped handles, likely a Middle Tyrrhenian re-elaboration of a Cypriot shape [13], had been stacked on a bronze stand interred along the north-western side of the lithic container [12](Fig.1a).

Load more

  22

Copy Link