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Testing the Effectiveness of Protocols for Removal of Common Conservation Treatments for Radiocarbon Dating

Published online by Cambridge University Press:  09 August 2017

Fiona Brock ,
Michael Dee ,
Andrew Hughes ,
Christophe Snoeck ,
Richard Staff  and
Christopher Bronk Ramsey
Fiona Brock*
Affiliation:
Cranfield Forensic Institute, Cranfield University, Defence Academy of the United Kingdom, Shrivenham, Oxon, SN6 8LA, United Kingdom
Michael Dee
Affiliation:
Research Laboratory for Archaeology & the History of Art, University of Oxford, Dyson Perrins Building, South Parks Road, Oxford, OX1 3QY, United Kingdom Centre of Isotope Research, Faculty of Science & Engineering, University of Groningen, Energy Academy Europe Building, Nijenborgh 6, 9747 AG Groningen, The Netherlands
Andrew Hughes
Affiliation:
Pitt Rivers Museum, University of Oxford, Oxford, OX1 3PP, United Kingdom
Christophe Snoeck
Affiliation:
Research Unit: Analytical, Environmental & Geo-Chemistry, Dept. of Chemistry, Vrije Universiteit Brussel, ESSC-WE-VUB, Pleinlaan 2, 1050 Brussels, Belgium
Richard Staff
Affiliation:
Research Laboratory for Archaeology & the History of Art, University of Oxford, Dyson Perrins Building, South Parks Road, Oxford, OX1 3QY, United Kingdom Scottish Universities Environmental Research Centre (SUERC), University of Glasgow, Rankine Avenue, Scottish Enterprise Technology Park, East Kilbride, G57 0QF, United Kingdom
Christopher Bronk Ramsey
Affiliation:
Research Laboratory for Archaeology & the History of Art, University of Oxford, Dyson Perrins Building, South Parks Road, Oxford, OX1 3QY, United Kingdom
*
*Corresponding author. Email: f.brock@cranfield.ac.uk.
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Abstract

To achieve a reliable radiocarbon (14C) date for an object, any contamination that may be of a different age must be removed prior to dating. Samples that have been conserved with treatments such as adhesives, varnishes or consolidants can pose a particular challenge to 14C dating. At the Oxford Radiocarbon Accelerator Unit (ORAU), common examples of such substances encountered include shellac, the acrylic polymers Paraloid B-67 and B-72, and vinyl acetate-derived polymers (e.g. PVA). Here, a non-carbon-containing absorbent substrate called Chromosorb® was deliberately contaminated with a range of varieties or brands of these conservation treatments, as well as two cellulose nitrate lacquers. A selection of chemical pretreatments was tested for their efficiency at removing them. While the varieties of shellac and Paraloid tested were completely removed with some treatments (water/methanol and acetone/methanol/chloroform sequential washes, respectively), no method was found that was capable of completely removing any of the vinyl acetate-derived materials or the cellulose nitrate lacquers. While Chromosorb is not an exact analog of archaeological wood or bone, for example, this study suggests that it may be possible to remove aged shellac and Paraloid from archaeological specimens with standard organic solvent-acid-base-acid pretreatments, but it may be significantly more difficult to remove vinyl acetate-derived polymers and cellulose nitrate lacquers sufficiently to provide reliable 14C dates. The four categories of conservation treatment studied demonstrate characteristic FTIR spectra, while highlighting subtle chemical and molecular differences between different varieties of shellac, Paraloid and cellulose nitrate lacquers, and significant differences between the vinyl acetate derivatives.

Keywords

chemical analysiscontaminationradiocarbon AMS dating
Type
Research Article
Information
Radiocarbon , Volume 60 , Issue 1 , February 2018 , pp. 35 - 50
Copyright
© 2017 by the Arizona Board of Regents on behalf of the University of Arizona 

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References

REFERENCES

Brock, F, Higham, T, Ditchfield, P, Bronk Ramsey, C. 2010. Current pretreatment methods for AMS radiocarbon dating at the Oxford Radiocarbon Accelerator Unit (ORAU). Radiocarbon 52(1):103–112.CrossRefGoogle Scholar
Brock, F, Ostapkowicz, J, Wiedenhoeft, AC, Bull, I. Radiocarbon dating wooden carvings and skeletal remains from Pitch Lake, Trinidad. Radiocarbon, in press.Google Scholar
Bruhn, F, Duhr, A, Grootes, PM, Mintrop, A, Nadeau, M-J. 2001. Chemical removal of conservation substances by “soxhlet”-type extraction. Radiocarbon 43(2A):229–237.CrossRefGoogle Scholar
Berglund, BE, Hakansson, S, Lagerlund, E. 1976. Radiocarbon dated mammoth (Mammuthus primigenius Blumenbach) finds in South Sweden. Boreas 5(3):177–191.CrossRefGoogle Scholar
Caforio, L, Fedi, M, Liccioli, L, Salvini, A. 2013. The issue of contamination by synthetic resins in radiocarbon dating: the case of a painting by Ambrogio Lorenzetti. Procedia Chemistry 8:28–34.CrossRefGoogle Scholar
Chapman, S, Mason, D. 2003. Literature review: the use of Paraloid B-72 as a surface consolidant for stained glass. Journal of the American Institute for Conservation 42(2):381–392.CrossRefGoogle Scholar
Dee, MW, Brock, F, Bowles, AD, Bronk Ramsey, C. 2011. Using a silica substrate to monitor the effectiveness of radiocarbon pretreatment. Radiocarbon 53(4):705–711.CrossRefGoogle Scholar
D’Elia, M, Gianfrate, G, Quarta, G, Giotta, L, Giancane, G, Calcagnile, L. 2007. Evaluation of possible contamination sources in the 14C analysis of bone samples by FTIR spectroscopy. Radiocarbon 49(2):201–210.CrossRefGoogle Scholar
France, CAM, Giaccai, JA, Cano, N. 2011. The effects of PVAc treatment and organic solvent removal on δ13C, δ15N, and δ18O values of collagen and hydroxyapatite in a modern bone. Journal of Archaeological Science 38:3387–3393.CrossRefGoogle Scholar
France, CAM, Giaccai, JA, Doney, CR. 2015. The effects of Paraloid B-72 and Butvar B-98 treatment and organic solvent removal on δ13C, δ15N, and δ18O values of collagen and hydroxyapatite in a modern bone. American Journal of Physical Anthropology 157(2):330–338.Google Scholar
Horie, V. 2010. Materials for Conservation: Organic Consolidants, Adhesives and Coatings. 2nd edition. London: Routledge.Google Scholar
Johnson, JS. 1994. Consolidation of archaeological bone: a conservation perspective. Journal of Field Archaeology 21(2):221–233.Google Scholar
Khairuddin, Pramano E, Utomo, SB, Wulandari, V, A’an Zahrotol, W, Clegg, F. 2016. The effect of polyethylene glycol on shellac stability. IOP Conference Series: Materials Science & Engineering 107:012066.Google Scholar
Koob, SP. 1979. The removal of aged shellac adhesive from ceramics. Studies in Conservation 24(3):134–135.Google Scholar
Koob, SP. 1982. The instability of cellulose nitrate adhesives. The Conservator 6:31–34.Google Scholar
Koob, SP. 1984. The continued use of shellac as an adhesive – why? Studies in Conservation 29(Sup1):103.CrossRefGoogle Scholar
Koob, SP. 1986. The use of Paraloid B-72 as an adhesive: its application for archaeological ceramics and other materials. Studies in Conservation 31:7–14.CrossRefGoogle Scholar
Larney, J. 1971. Ceramic conservation in the Victoria and Albert Museum. Studies in Conservation 16:69–82.CrossRefGoogle Scholar
Law, IA, Housley, RA, Hammond, N, Hedges, REM. 1991. Cuello: resolving the chronology through direct dating of conserved and low-collagen bone by AMS. Radiocarbon 33(3):303–315.CrossRefGoogle Scholar
Moore, KM, Murray, ML, Schoeninger, MJ. 1989. Dietary reconstruction from bones treated with preservatives. Journal of Archaeological Science 16:437–446.CrossRefGoogle Scholar
Nel, P. 2006. A preliminary investigation into the identification of adhesives on archaeological pottery. AICCM Bulletin 30:27–37.Google Scholar
Nel, P, Lau, D. 2009. Identification of a formulation change in a conservation grade adhesive. In: Ambers J, Higgit C, Harrison L, Saunders D, editors. Conference proceedings, Holding it all Together, Ancient and Modern Approaches to Joining, Repair and Consolidation, British Museum. London Archetype Publications. p 99–106.Google Scholar
Nel, P, Lonetti, C, Lau, D, Tam, K, Sagona, A, Sloggett, RS. 2010. Analysis of adhesives used on the Melbourne University Cypriot pottery collection using a portable FTIR-ATR analyser. Vibrational Spectroscopy 53:64–70.Google Scholar
Nishimoto, H. 2011. High precision radiocarbon dating of archaeological waterlogged wood: focusing on wooden poles forming circular structures at the Mawaki site [PhD thesis]. Nagoya University, Japan.Google Scholar
Oddy, WA. 1973. An unsuspected danger in display. Museums Journal 73:27–28.Google Scholar
Ohlídalová, M, Kučerová, I, Novotná, M. 2006. Identification of acrylic consolidants in wood by Raman spectroscopy. Journal of Raman Spectroscopy 37(10):1179–1185.Google Scholar
Ostapkowicz, J, Schulting, RJ, Wheeler, R, Newsom, L, Brock, F, Bull, I, Snoeck, C. 2017. East-central Florida pre-Columbian wood sculpture: radiocarbon dating, wood identification and strontium isotope studies. Journal of Archaeological Science: Reports 13:595–608.Google Scholar
Ramirez Rozzi, FV, d’Errico, F, Vanhaeren, M, Grootes, PM, Kerautret, B, Dujardin, V. 2009. Cutmarked human remains bearing Neanderthal features and modern human remains associated with the Aurignacian at Les Rois. Journal of Anthropological Sciences 87:153–185.Google Scholar
Robinet, L, Thickett, D. 2003. A new methodology for accelerated corrosion testing. Studies in Conservation 48(4):263–268.CrossRefGoogle Scholar
Shashoua, Y, Bradley, SM, Daniels, VD. 1992. Degradation of cellulose nitrate adhesive. Studies in Conservation 37(2):113–119.Google Scholar
Shelton, SY, Chaney, DS. 1993. An evaluation of adhesives and consolidants recommended for fossil vertebrates. In: Leiggi P, May P, editors. Vertebrate Palaeontological Techniques Volume 1. Cambridge: Cambridge University Press. p 35–45.Google Scholar
Stevens, RE, Hedges, REM. 2004. Carbon and nitrogen stable isotope analysis of northwest European horse bone and tooth collagen, 40,000 BP–present: palaeoclimatic interpretations. Quaternary Science Reviews 23:977–991.Google Scholar
Tuross, N, Fogel, MI. 1994. Exceptional molecular preservation in the fossil record: the archaeological, conservation and scientific challenge. In: Scott DA, Meyers P, editors. Archaeometry of Pre-Columbian Sites. Los Angeles: The Getty Conservation Institute. p 367–380.Google Scholar
Yuan, S, Wu, X, Liu, K, Guo, Z, Cheng, X, Pan, Y, Wang, J. 2007. Removal of contaminants from oracle bones during sample pretreatment. Radiocarbon 49(2):211–216.Google Scholar