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This work presents the results of a study of the resins of seven Ancient Egyptian mummies from the collection of the Pushkin State Museum of Fine Arts using a complex of analytical methods: gas chromatography, atomic emission and mass spectrometry. Natural bitumen and beeswax were identified in the resins using the gas chromatography–mass spectrometry method. Based on the results of hydrocarbon distribution in the profiles of n-alkanes in the resin coatings of the mummies and naturally occurring bitumen, it was assumed that the Dead Sea bitumen was used. The gas chromatography–mass spectrometry studies of mummy resins in the selected ion mode (m/z 217 and 191) provided additional evidence of the bitumen’s geographic origin. Atomic emission spectrometry with inductively coupled plasma was used as a means to determine the content of microelements. Vanadium, nickel and molybdenum were found in the tar of five mummies. The determined relative amounts of vanadium, nickel, and molybdenum in the resins of the studied mummies showed a good correlation with the available data on the content of these elements in the Dead Sea bitumen, as well as the Fayum mummy resin based on this bitumen. The advantages of using the method of identifying bitumen in mummy resins based on relative content of vanadium, nickel, and molybdenum were revealed.

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Background: Fundamental restoration of sculptures must include the research of pollution composition and exhibit surface condition as well as accurate identification of the materials of sculptures, bas-reliefs and coatings. In the recent years, studies of marble objects aimed at identification of contamination nature and composition have been developed. It should be noted that some exhibits have individual features as objects of restoration due to complex exposure to the environment, e.g. to fire. Results: The article describes the results of surface contamination study on two exhibits from the Pushkin State Museum of Fine Arts collection. Marble relief sculpture "The Flagellation of Christ" was the main object of the study. Glazed terracotta (majolica) "Madonna Friedrichshain" was studied as a control sample with the same type of contaminations but with less sensitive surface. According to the results of different gas chromatography and X-ray fluorescence analyses, pollution compounds were identified as fatty alcohols, fatty acids and esters, part of which being residues of pyrolysis gasification, including those containing iron and lead. In order to gently clean the exhibits, several variants of chemical compounds were proposed based on various chelating agent mixtures, and, after studying their comparative effectiveness, the optimal scheme was chosen for removing existing contamination. For verification of marble exhibits safety, selected cleaning mixtures were tested on polished Carrara marble sample. Conclusion: The most suitable scheme of organic contaminations removal including those containing iron and lead was suggested as part of restoration process. There is a number of working schemes of cleaning the surface of exhibits, however our proposed scheme interacts with the marble surface more gently because the target cleaning mixture composition was formulated taking into account the nature of pollutants and the least possible impact on the sample surface.

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