Multi-analytical study of the archaeological leather discovered near the medieval Oratea fortress

Cercetări Arheologice 29.1, 2022, 185-196
https://doi.org/10.46535/ca.29.1.10



Multi-analytical study of the archaeological leather discovered near the medieval Oratea fortress

Authors: Cristina Carsote Elena Badea Eugen S. Teodor

Keywords:

archaeological leather, FTIR-ATR, micro DSC, XRF, SEM, decay

Abstract:

Recent archaeological excavations made on the plateau located east of the medieval fortress at Oratea (Podu Dâmboviţei, Argeş County) evidenced a fortified position of the Roman Age. Among other finds there is a relatively large leather fragment, belonging to the earliest phase (beginning of the second century AD). This discovery is extremely rare since suitable preservation conditions for leather are rarely meet in the specific soil and climate conditions in Romania. The contact with atmosphere induced sudden dehydration and consequent fragmentation of leather, which required a multi-analytical approach to extract useful information about its degradation condition. A combination of molecular (Fourier transform infrared spectroscopy in attenuated total refection mode, FTIR-ATR) and elemental (X-ray fluorescence, XRF) spectroscopic techniques with micro differential scanning calorimetry (micro-DSC) and scanning electron microscopy (SEM) was applied to this purpose.

FTIR-ATR analysis allowed us to detect gelatin on the samples’ surface based on the collagen spectral components. Collagen extended de-tanning, gelatinisation and conversion into amorphous structures was quantified by microDSC. The alterations of leather microstructure and morphology were observed by high magnification SEM. XRF analysis also provided the elemental composition of soil. Overall, the archaeological samples shown extremely high fragility and the tendency to turn into powder on drying. This behaviour is due to the gelatinous-amorphous structure of leather strengthened only by the mineral components of the soil. Given the extremely high risk of loss, the authors recommend the application of a consolidation method based on halloysite and other nanoclays incorporation with utmost urgency.

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How to cite: Cristina Carsote, Elena Badea, Eugen S. Teodor, Multi-analytical study of the archaeological leather discovered near the medieval Oratea fortress, Cercetări Arheologice, Vol. 29.1, pag. 185-196, 2022, doi: https://doi.org/10.46535/ca.29.1.10

Bibliography

  1. Badea, E., Carsote, C., Habimbu, E., Sendrea, C., Lupas, M.C., and Miu, L., 2019. The effect of halloysite nanotubes dispersions on vegetable-tanned leather thermal stability, Heritage Science 7:68. https://doi.org/10.1186/s40494-019-0310-x.
  2. Badea, E., Della Gatta, G., Usacheva, T., 2011. Effects of temperature and relative humidity on fibrillar collagen within parchment: a micro Differential Scanning Calorimetry (micro DSC) study. Polymer Degradation and Stability 97:346-53.
  3. Baglioni, M., Poggi, G., Chelazzi, D., and Baglioni, P., 2021. Advanced Materials in Cultural Heritage Conservation. Molecules 26: 3967. https://doi.org/10.3390/molecules26133967
  4. Barth, A., 2007. Infrared spectroscopy of proteins. Biochimica et Biophysica Acta Bioenergetics 1767: 1073–1101. https://doi.org/10.1016/j.bbabio.2007.06.004 .
  5. Brandt, L. Ø., Haase, K., and Collins, M. J., 2018. Species identification using ZooMS, with reference to the exploitation of animal resources in the medieval town of Odense, Danish Journal of Archaeology 7, 2: 139-153, DOI: 10.1080/21662282.2018.1468154
  6. Budrugeac, P., Carșote, C., and Miu, L., 2017. Application of thermal analysis methods for damage assessment of leather in an old military coat belonging to History Museum of Braşov – Romania, Journal of Thermal Analysis and Calorimetry 127: 765-762.
  7. Carsote, C., Badea, E., Miu, L., and Della Gatta, G., 2016. Study of the efect of tannins and animal species on the thermal stability of vegetable leather by diferential scanning calorimetry. Journal of Thermal Analysis and Calorimetry 124: 1255-1266. https://doi.org/10.1007/s10973-016-5344-7 
  8. Carsote, C., Şendrea, C., Micu, M.C., Adams, A., and Badea, E., 2021. Micro-DSC, FTIR-ATR and NMR MOUSE study of the dose-dependent efects of gamma irradiation on vegetable-tanned leather: the infuence of leather thermal stability. Radiation Physics and Chemistry 189: 109712. https://doi.org/10.1016/j. radphyschem.2021.109712 .
  9. Carsote, C., and Badea, E., 2019. Micro diferential scanning calorimetry and Micro Hot Table method for quantifying deterioration of historical leather. Heritage Science 7, 48: 1-13. https://doi.org/10.1186/s40494-019-0292-8 .
  10. Carsote, C., Badea, E., Caniola, I., Paunescu, S., Lupas, M.C., Sendrea, C., and Miu, L., 2020. The Homiliary of Varlaam: scientific investigation of the leather bookbinding. Revista de Chimie 71, 3: 51–8. https://doi.org/10.37358/RC.20.3.7973 .
  11. Carsote, C., Kövari, L., Albu, C., Hadimbu, E., Badea, E., Miu, L., and Dumitrescu, G., 2018. Bindings of Rare Books from the collections of the Romanian Academy Library – a multidisciplinary study, Leather and Footwear Journal 18, 4: 307-320.
  12. Cavallaro, G., Milioto, S., and Lazzara, G., 2020. Halloysite Nanotubes: Interfacial Properties and Applications in Cultural Heritage, Langmuir 36, 14: 3677-3689.
  13. Covington, AD., 2019 Tanning chemistry: the science of leather. In: Wise W, Covington AD, editors. Cambridge: The Royal Society of Chemistry, 195-202.
  14. Crone, A., Sands, R. and Skinner, T., 2007. The waterlogged wood assemblage. In: Thomas2007b, 101-15.
  15. Ebsen, J.A., Haase, K., Larsen, R., Poulsen Sommer, D.V., and Brandt, L. Ø., 2019. Identifying archaeological leather – discussing the potential of grain pattern analysis and zooarchaeology by mass spectrometry (ZooMS) through a case study involving medieval shoe parts from Denmark, Journal of Cultural Heritage 39: 21-31, https://doi.org/10.1016/j.culher.2019.04.008
  16. Falcão, L., and Araújo, M.E.M., 2018. Vegetable tannins used in the manufacture of historic leathers. Molecules 23:8–10. https://doi.org/10.3390/molec ules23051081 .
  17. Forbes, RJ., 1957. Leather in Antiquity. Studies in Ancient Technology. 1st ed. Brill Publishers. Leiden: The Netherlands 5:1 −77.
  18. Groenman-van Waateringe, W., 2007. Leather. In: Hanson, W. S. with Speller, K., Yeoman,P.A. and Terry, J., Elginhaugh: a Flavian Fort and its Annexe, Volume 2. London: Societyfor the Promotion of Roman Studies, 470-478.
  19. Goffer, Z., 2007. Archaeological Chemistry 2nd Edition, John Wiley & Sons, INC.
  20. Haslam, E., 1997. Vegetable tannage: Where do the tannins go?. Journal of the society of Leather Technologists and Chemists 81:45–51.
  21. Larsen, R., Vest, M., and Nielsen, K., 1993. Determination of hydrothermal stability (shrinkage temperature) of historical leathers by Micro Hot Table technique. Journal of the society of Leather Technologists and Chemists 77: 151-156.
  22. Larsen, R., Vest, M., and Nielsen, K., 1994. Determination of hydrothermal stability. In: Larsen R, Vest M, Kejser UB, editors. STEP Leather Project. Evaluation of the correlation between natural and artifcial ageing of vegetable tanned leather and determination of parameters for standardization of an artifcial ageing method. Copenhagen: Bjarnholt Repro, p. 151-164.
  23. M-Kiss, H., 2007. Obiecte de piele, in F. Drașovean (editor), Timișoara în amurgul evului mediu. rezultatele cercetărilor arheologice preventive din centrul istoric, Timișoara: Mirton, 161-220.Miles, CA., 1993. Kinetics of collagen denaturation in mammalian lens capsules studied by differential scanning calorimetry. International Journal of Biological Macromolecules 15:265–71.
  24. Malea, E., 2010. Assessment of physical condition of waterlogged archaeological leather. Proceedings of the 11th ICOM-CC WOAM (waterlogged Organic Archaeological Materials) Conference, p. 571-594
  25. Payne, K. J., and Veis, A., 1988. Fourier transform ir spectroscopy of collagen and gelatin solutions: Deconvolution of the amide I band for conformational studies. Biopolymers 27: 1749-1760.
  26. Pollard, A.M., Batt, C.M., Stern, B., Young, S.M.M., 2007. Analytical chemistry in archaeology. Cambridge University Press New York
  27. Pop, M., 2013. Paleology and old history of footwear in Romania, Revista de Pielarie Incaltaminte13(3): 235-246.
  28. Proietti, N., Di Tullio, V., Carsote, C., and Badea, E., 2020. 13C solid-state NMR complemented by ATR-FTIR and micro-DSC to study modern collagen-based material and historical leather. Magnetic Resonance in Chemistry 58: 840–859. https://doi.org/10.1002/mrc.5024 .
  29. Sebestyén, Z., Badea, E., Carsote, C., Czégény, Z., Szabó, T., Babinszki, B., and Jakab, E., 2022. Characterization of historical leather bookbindings by various thermal methods (TG/MS, Py-GC/MS, and micro-DSC) and FTIR-ATR spectroscopy, Journal of Analytical and Applied Pyrolysis 162: 105428. https://doi.org/10.1016/j.jaap.2021.105428 .
  30. Sykes, R.L., 1991. The Principles of Tanning, in Leather its composition and changes with time, C. Calnan and B. Haines Editors, The Leather Conservation Centre, Northampton.
  31. Teodor, E.S., 2022. New research around the Oratea Fortress, Cercetări Arheologice, 29, 1 (this volume), 155-184.
  32. Van Driel-Murray, C., 2001d. Footwear in the North-Western Provinces of the Roman Empire. In: Goubitz et al 2001, 337-76.
  33. Vichi, A., Eliazyan, G., and Kazarian, S.G., 2018. Study of the degradation and conservation of historical leather book covers with Macro Attenuated Total Refection-Fourier Transform Infrared Spectroscopic Imaging. ACS Omega 3:7150–7157.
  34. Vyskočilová, G., Ševčík, R., Carşote, C., and Badea, E., 2022. Burial-induced deterioration in leather: a FTIR-ATR, DSC, TG/DTG, MHT and SEM study, Heritage Science 10: 7 https://doi.org/10.1186/s40494-021-00638-6

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