Study of Egyptian mummification balms by FT-IR spectroscopy and GC–MS

Found in the Folds: A Rediscovery of Ancient Egyptian Pleated Textiles and the Analysis of Carbohydrate Coatings

Charles T. Currelly, first director of the Royal Ontario Museum, participated in excavations of the tomb of King Nebhepetre, now known as Mentuhotep II, (Dynasty XI) in Deir el-Bahri, Egypt in 1906. He brought to Canada many objects from the excavations, and objects that he purchased while in Egypt; these formed the initial collection of the museum. Among the objects were seven fragments of fine linen cloth with intricate pleat patterns. Recently, the cloths became the subject of a study to learn how they had retained their pleats for 4000 years. Samples were examined and analysed using polarised light microscopy, scanning electron microscopy-electron dispersive X-ray spectrometry, gas chromatography-mass spectrometry, and pyrolysis-gas chromatography-mass spectrometry. Three of the cloths were likely fragments of clothing re-purposed as bandages and were found to be saturated in mummification balms composed of Pinaceae resin, Pistacia resin, and an essential oil characterised by a high abundance of cedrol, possibly originating from a juniper species. All seven of the cloths were found to have traces of polysaccharides from two probable sources: an arabinogalactan gum such as gum arabic or a fruit gum, and a polyglucoside, possibly starch.

Rethinking the Process of Animal Mummification in Ancient Egypt: Molecular Characterization of Embalming Material and the Use of Brassicaceae Seed Oil in the Mummification of Gazelle Mummies from Kom Mereh, Egypt

The study of animal mummification in ancient Egypt has recently received increasing attention from a number of modern scholars given the fact that this part of ancient Egyptian funerary and religious history is a practice yet to be fully understood. In this study, nine samples of embalming matter were extracted from six gazelle mummies from the archaeological site of Kom Mereh (modern village of Komir), dated to the Roman period of dominance in ancient Egypt. All samples were analyzed for the presence of inorganic and organic matter applying a multi-analytical approach based on Fourier transform infrared spectroscopy (FT-IR) and gas chromatography–mass spectrometry (GC-MS). Furthermore, in order to identify more specific compounds such as bitumen and beeswax in studied balms, each sample was subjected to a solid phase extraction (SPE) and saponification separation process, respectively. The results of this study revealed that the majority of the analyzed embalming substances sampled from six gazelle mummies from Kom Mereh were complex mixtures of plant oils, animal fats, conifer resin, and beeswax. In this regard, this study was able to report a practice until now unmentioned in the scientific literature, namely, the use of cruciferous oil, derived from seeds of Brassicaceae plants, in animal mummification.

Fatty Acids and Their Metal Salts: A Review of Their Infrared Spectra in Light of Their Presence in Cultural Heritage

In a cultural heritage context, fatty acids are usually found as breakdown products of lipid-containing organic remains in archaeological findings, binders in aged oil paintings, and additives in modern art-related materials. They may further interact with the ionic environment transforming into metal soaps, a process that has been recognized as a threat in aged paintings but has received less attention in archaeological objects. The investigation of the above related categories of materials with infrared spectroscopy can provide an overall picture of the organic components' identity and demonstrate their condition and prehistory. The capability of investigating and distinguishing fatty acids and their metal soaps through their rich infrared features, such as the acidic carbonyl, the carboxylate shifts, the variable splits of alkyl chain stretching, bending, twisting, wagging, and rocking vibrations, as well as the hydroxyl peak envelopes and acid dimer bands, allows for their direct detailed characterization. This paper reviews the infrared spectra of selected saturated fatty monoacids and diacids, and their corresponding sodium, calcium, and zinc salts and, supported by newly recorded data, highlights the significance of their spectroscopic features.

A Multi-Analytical Study of Egyptian Funerary Artifacts from Three Portuguese Museum Collections

A diachronic, multi-analytical approach combining EDXRF, µFTIR, µRaman, SEM-EDS, and Py-GC/MS has been adopted with the aim to study for the first time the painting materials used to decorate Egyptian funerary masks and sarcophagi ranging from the Late Period to the Roman Period and stored in the Archaeological National Museum (MNA) and the Carmo Archaeological Museum (MAC) of Lisbon and the Natural History Museum of the University in Oporto (MNH-FCUP). Results indicate that yellow and red ochres, realgar, cinnabar, Egyptian blue, and Egyptian green were used as pigments while chalk served as the preparatory layer. Over the 1000-year timeline of the studied artifacts, the palette remained remarkably consistent with previous findings as exemplified by cinnabar being used for red pigments in samples only dated after the Ptolemaic period. The presence of Sn in Egyptian blue and Egyptian green pigments used in one sample suggests the use of recycled bronze scraps during pigment production. Black pigments in two Late Period masks were found to be produced by mixing Egyptian blue with red ochre suggesting either a hitherto unknown method for production of purple pigments in the Egyptian palette or, alternatively, an attempt to create a specific hue or shade of dark brown or black. The results of this study contribute to further expand the database of Ancient Egyptian painting materials while at the same time helping to valorize three important Egyptian collections in Portugal.

Molecular analysis of black coatings and anointing fluids from ancient Egyptian coffins, mummy cases, and funerary objects

Previous studies of ritual black coatings on coffins from ancient Egypt have taken single small samples from objects of wide-ranging time periods and have conflated different types of application. This study takes 100 samples of black ritual liquids identified by type of application and precisely located on the objects, to allow the results to be fully contextualized within the wider discipline. It shows that black coatings on coffins were made using a remarkably consistent selection of natural products. The molecules identified in these black coatings overlap with those used in Egyptian mummification balms, which may suggest a link among separate applications: preparation of the body for burial, decoration of the coffin, and rites performed during the funeral.

Black organic coatings and ritual deposits on ancient Egyptian coffins and cartonnage cases are important and understudied sources of evidence about the rituals of funerary practice. Sometimes, the coatings were applied extensively over the surface of the coffin, resembling paint; in other cases, they were poured over the mummy case or wrapped body, presumably as part of a funerary ritual. For this study, multiple samples of black coatings and ritual liquids were taken from 20 Egyptian funerary items dating to a specific time period (c. 943 to 716 BC). Multiple sampling from each object enabled several comparisons to be made: the variability of the black coating within one application, the variability between two applications on one object, and the variability from object to object. All samples were analyzed for lipids using gas chromatography–mass spectrometry (GC-MS), and 51 samples from across the 20 items were further analyzed for the presence of bitumen using solid phase separation followed by selected ion monitoring GC-MS. The majority of the black substances were found to comprise a complex mixture of organic materials, including bitumen from the Dead Sea, conifer resin, and Pistacia resin, providing evidence for a continuation in international trade between Egypt and the eastern Mediterranean after the Late Bronze Age. Both the coating and the anointing liquid are very similar to mummification balms, pointing to parallels with Egyptian embalming rituals and raising questions about the practical aspects of Egyptian funerary practice.

Evaluation of a characterization method of Egyptian human mummy balms by chemometric treatments of infrared data

In the context where lengthy protocols are used to extract and to characterize each substance from mummification balms using techniques such as gas chromatography and mass spectrometry, this paper presents the evaluation of the efficiency of an original method to characterize mummification balms using the SIMPLISMA algorithm in infrared spectroscopy. This tool is a pure variable approach corresponding to the selection of calibration variables. This developed approach was combined with chemometric treatment (principal component analysis) to interpret the 47 Fourier Transform Infrared spectra of human mummies' balms from Ancient Egypt. This treatment gave 6 pure spectra and their corresponding extracted concentration profiles. The first pure spectrum corresponded to residual species, and the second to the identification of polycyclic aromatic hydrocarbons, molecules which have a pyrolytic origin. The fourth pure spectrum corresponded to proteins which were characterized, and could be considered as markers of good conservation of individuals. The fifth pure spectrum characterized polysaccharides. Finally, two pure spectra showed the same natural substance, namely fat, which, on the one hand, was unaltered and, on the other hand, was degraded fatty matter. This fast, simple and non-destructive approach allowed the composition of each balm to be studied and their state of conservation/degradation to be characterized. This approach enabled the presence of proteins, polysaccharides and fatty matter or beeswax in different states of conservation/alteration in the studied balms to be characterized.

Analysis of balms taken from Egyptian human mummies using solid-phase extraction and gas chromatography-mass spectrometry

The aim of this paper is to establish a protocol by solid-phase extraction-gas chromatography-mass spectrometry leading to a wide and fine qualitative chemical characterization of the several natural substances present in human mummies' balms, using a minimal quantity of samples. In this study, nine samples were analyzed from mummies dating back from the Third Intermediate Period to the Roman Period, and were provided by the Confluences Museum (Lyon, France). Using solid-phase extraction, three fractions were examined in this protocol. The first one, eluted with hexane, concerned chemical families of hydrocarbons of bitumen. The second, eluted with ethanol, enabled terpenic compounds to be characterized and beeswax. The last one, composed of diethyl ether with 2% acetic acid, extracted carboxylic acids with a long aliphatic chain (fatty matter) and glycerides. This study also allowed the characterization of non-saponified compounds from beeswax to be obtained while excluding the common saponification step. The analyzed mummification balms were shown to contain fatty matter, beeswax, bitumen, and diterpenic resinous material. This one-pot solid-phase extraction-gas chromatography-mass spectrometry method was efficient in reducing both the number of analytical steps and the complexity of the archaeological balms subsequently analyzed by gas chromatography-mass spectrometry.

Bitumen from the Dead Sea in Early Iron Age Nubia

Bitumen has been identified for the first time in Egyptian occupied Nubia, from within the town of Amara West, occupied from around 1300 to 1050 BC. The bitumen can be sourced to the Dead Sea using biomarkers, evidencing a trade in this material from the eastern Mediterranean to Nubia in the New Kingdom or its immediate aftermath. Two different end uses for bitumen were determined at the site. Ground bitumen was identified in several paint palettes, and in one case can be shown to have been mixed with plant gum, which indicates the use of bitumen as a ground pigment. Bitumen was also identified as a component of a friable black solid excavated from a tomb, and a black substance applied to the surface of a painted and plastered coffin fragment. Both contained plant resin, indicating that this substance was probably applied as a ritual funerary liquid, a practice identified from this time period in Egypt. The use of this ritual, at a far remove from the royal Egyptian burial sites at Thebes, indicates the importance of this ritual as a component of the funeral, and the value attributed to the material components of the black liquid.

Synchrotron "virtual archaeozoology" reveals how Ancient Egyptians prepared a decaying crocodile cadaver for mummification

Although Ancient Egyptians mummified millions of animals over the course of one millennium, many details of these mummification protocols remain unknown. Multi-scale propagation phase-contrast X-ray synchrotron microtomography was used to visualise an ancient Egyptian crocodile mummy housed at the Musée des Confluences (Lyon, France). This state-of-the-art non-destructive imaging technique revealed the complete interior anatomy of the mummy in three dimensions. Here, we present detailed insight into the complex post-mortem treatment of a decaying crocodile cadaver in preparation for mummification. Except for the head and the extremities of the limbs, everything beneath the skin of the crocodile (i.e. organs, muscles, and even most of the skeleton) was removed to cease further putrefaction. This unexpected finding demonstrates that earlier knowledge obtained from textual and other archaeological sources does not sufficiently reflect the diversity of mummification protocols implemented by Ancient Egyptians.

Multidisciplinary investigation of two Egyptian child mummies curated at the University of Tartu Art Museum, Estonia (Late/Graeco-Roman Periods)

Two ancient Egyptian child mummies at the University of Tartu Art Museum (Estonia) were, according to museum records, brought to Estonia by the young Baltic-German scholar Otto Friedrich von Richter, who had travelled in Egypt during the early 19th century. Although some studies of the mummies were conducted, a thorough investigation has never been made. Thus, an interdisciplinary team of experts studied the remains using the most recent analytical methods in order to provide an exhaustive analysis of the remains. The bodies were submitted for osteological and archaeothanatological study, radiological investigation, AMS radiocarbon dating, chemical and textile analyses, 3D modelling, entomological as well as aDNA investigation. Here we synthesize the results of one of the most extensive multidisciplinary analyses of ancient Egyptian child mummies, adding significantly to our knowledge of such examples of ancient funerary practices.

The multimodal chemical study of pre-Columbian Peruvian mummies

In the pre-Hispanic Central Andes, the mummified bodies of ancestors stood as the basis for the social and cosmic order. This work discusses chemical compositions of the bodies determined by using molecular and elemental analytical methods.

Untargeted metabolomics-like screening approach for chemical characterization and differentiation of canopic jar and mummy samples from Ancient Egypt using GC-high resolution MS

Canopic jarsvs.mummies: first time use of modern metabolomic techniques to unravel ancient embalming chemistry.

Origin Discrimination of Osmanthus fragrans var. thunbergii Flowers using GC-MS and UPLC-PDA Combined with Multivariable Analysis Methods

INTRODUCTION

Osmanthus fragrans flowers are used as folk medicine and additives for teas, beverages and foods. The metabolites of O. fragrans flowers from different geographical origins were inconsistent in some extent. Chromatography and mass spectrometry combined with multivariable analysis methods provides an approach for discriminating the origin of O. fragrans flowers.

OBJECTIVE

To discriminate the Osmanthus fragrans var. thunbergii flowers from different origins with the identified metabolites.

METHODS

GC-MS and UPLC-PDA were conducted to analyse the metabolites in O. fragrans var. thunbergii flowers (in total 150 samples). Principal component analysis (PCA), soft independent modelling of class analogy analysis (SIMCA) and random forest (RF) analysis were applied to group the GC-MS and UPLC-PDA data.

RESULTS

GC-MS identified 32 compounds common to all samples while UPLC-PDA/QTOF-MS identified 16 common compounds. PCA of the UPLC-PDA data generated a better clustering than PCA of the GC-MS data. Ten metabolites (six from GC-MS and four from UPLC-PDA) were selected as effective compounds for discrimination by PCA loadings. SIMCA and RF analysis were used to build classification models, and the RF model, based on the four effective compounds (caffeic acid derivative, acteoside, ligustroside and compound 15), yielded better results with the classification rate of 100% in the calibration set and 97.8% in the prediction set.

CONCLUSIONS

GC-MS and UPLC-PDA combined with multivariable analysis methods can discriminate the origin of Osmanthus fragrans var. thunbergii flowers. Copyright © 2017 John Wiley & Sons, Ltd.

Ageing of resin from Pinus species assessed by infrared spectroscopy

Resins obtained from Pinus genus species have been widely used in very different fields throughout history. As soon as the resins are secreted, molecular changes start altering their chemical, mechanical and optical properties. The ageing processes are complex, and the chemical and structural changes associated with resin degradation are not yet fully known. Many questions still remain open, for instance changes happening in pimaranes, one of the two diterpenoid constituents of the resin. A systematic study of the ageing process of Pinus resins is done through Fourier transform infrared spectroscopy (FTIR) using chemical standards and complementing the obtained results with gas chromatography coupled to mass spectrometry (GC/MS) analysis when necessary. Moreover, long-term degradation processes are also investigated through the analysis of a selection of dated historical resins. This study overcomes the limitations of GC/MS and brings new information about the reactions and interactions between molecules during Pinus resin ageing processes. It also provides information about which bonds are affected and unaffected, and these can be used as specific markers of the degradation and of the resins themselves. Graphical Abstract Changes in the IR spectral features due to the Pinus resin ageing processes.