Advances in the characterisation and identification of mastic (Pistacia sp.) resin in archaeological samples by GC-QToF-MS.

The optimisation and application of an analytical method based on gas chromatography coupled to quadrupole time-of-flight mass spectrometry (GC-QToF-MS) is proposed for the first time for the characterisation and identification of mastic (Pistacia sp.) resin in archaeological samples. The GC-QToF-MS method demonstrated higher sensitivity compared to single quadrupole GC-MS and enabled enhanced structural elucidation power to be exploited, particularly due to the high mass resolution and accuracy, the possibility to use standard and low ionisation energies as well as its tandem MS capabilities. The heat-induced degradation of the resin was also studied in open air conditions, showing that 28-norolean-17-en-3-one forms upon heating, but then progressively degrades. This makes it a reliable marker for heating of Pistacia resin; however, the lack of detection does not imply that the resin was not heated. These observations were used to interpret the results of a large number of archaeological samples containing Pistacia resin in different formulations, from various archaeological contexts and exposed to different environmental conditions. Lumps of relatively pure resin found in marine waterlogged conditions (Uluburun shipwreck, Turkey), residues on ceramics from Sai Island (Nubia, Sudan) as well as varnish and coating layers on Egyptian coffins from the collections of the British Museum (London, UK) and Fitzwilliam Museum (Cambridge, UK) were analysed to understand what the molecular profiles reveal about the use of the resin. The results showed that the resin was often mixed with a drying or semi-drying oil in ancient varnish formulations, thus suggesting that oil was used as a medium to dissolve the resin, which would have been impossible to apply as a layer using simple heat. These new observations significantly add to our understanding of ancient Egyptian technology and provide museum scientists and conservators with key information to accurately identify Pistacia resin and preserve objects containing it.

Reshaping Egyptian funerary ritual in colonized Nubia? Organic characterization of unguents from mortuary contexts of the New Kingdom (c. 1550-1070 BCE).

Samples taken from the canopic jars of Djehutyhotep, chief of Tehkhet (Debeira), Lower Nubia, and local versions of Egyptian canopic jars from Sai, Upper Nubia, suggest that the materials used for mortuary ritual unguents in Nubia may have differed from those used in Egypt. Nubian samples consisted of plant gum and bitumen, whereas those from Egypt conformed to the standardizing black resinous liquid recipe used for mummification and other funerary rituals. However, there may be time frame issues to be considered as most samples analyzed from Egypt date to later periods. A standard black funerary liquid was used at Amara West, Upper Nubia, probably poured over a wrapped body, which might suggest that the gum and bitumen mixture was reserved for filling canopic jars, perhaps indicating that the use of canopic jars in Nubia differed from their use in Egypt. Evidence from the canopic jars of Djehutyhotep, local versions of canopic jars from Sai, and the sample from Amara West also indicate a source of bitumen that was not the Dead Sea, which was the main (although not only) source used in Egypt. The new results from the analysis of the Djehutyhotep canopic jars and previously published results from Sai point towards alternative ritual practices associated with local conceptions and uses of canopic jars in colonized Nubia. These samples and data from Amara West further reveal that the bitumen used in mortuary contexts in Nubia originated elsewhere than bitumen used in Egypt, which might have implications for our understanding of colonized Nubia as part of other trade networks independently from Egypt.

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

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.

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.