Spectrophotometric Determination of PEG in Waterlogged Archaeological Wood and Impregnation Solutions

ABSTRACT

The aim of the present work was to test the applicability of the spectrophotometric method for the determination of polyethylene glycol (PEG) 4000 using bismuth subnitrate (BiONO₃) to monitor the content of PEG in impregnated archaeological wood. Absorption spectra were collected in the visible light (VIS) range from 400 to 600 nm. The weight of the wood samples tested ranged from 50 to 120 mg. The PEG content was measured in aqueous extracts with the concentration of up to 30 mg·L⁻¹. The results confirmed the high sensitivity and precision of the method used. The performed analyses were characterized by repeatability and selectivity towards PEG 4000 in a mixture containing PEG 300. The applicability of the PEG 2000 quantitative determination method was confirmed.

KEYWORDS:

• PEG
• waterlogged archaeological wood
• spectrophotometry
• conservation
• impregnation
• Dragendorff reagent

Acknowledgements

The authors would like to thank Prof. Józef Garbarczyk, former Rector of Hipolit Cegielski State University of Applied Sciences in Gniezno and Wiesław Zajączkowski, former Director of the Archaeological Museum in Biskupin, for the possibility of carrying out research as part of an interdisciplinary project; Prof. Magdalena Zborowska for a critical look and posing valuable questions; and Justyna Łuczka for graphics work and anonymous reviewers for language corrections.

Disclosure statement

No potential conflict of interest was reported by the author(s).