Solvent-extractable components of linseed oil paint films

As part of an investigation into the risks associated with the exposure of oil paintings to organic solvents in cleaning and other conservation treatments, the extraction of soluble organic components from a variety of pigmented oil films was studies. The extractable material was characterized using chromatographic, spectroscopic and mass spectrometric techniques, and quantified using weight measurements and gas chromatographic analysis of extractable fatty acids. The influence on the leaching process of factors such as pigmentation and age of the paint films, and the type of solvent treatment, was examined. In addition to laboratory-prepared paint films from three to 65 years old, samples from paintings dating from as early as the thirteenth century were analysed, to enable the data from the younger test films to be put in a more practical context. Experiments to measure the extent of leaching resulting from simulated cleaning treatments on paintings dating from the seventeenth to nineteenth centuries are also reported.