“Yuton” is a Japanese traditional carpet, consisting mainly of Japan paper and perilla oil. Yuton has the unique property that its strength and repellency become the highest after 20-30 years of use. In this review, some features of thermochemolysis-gas chromatography (thermochemolysis-GC) in the presence of organic alkali are first presented. Then, applications of thermochemolysis-GC to structural analysis of perilla oil components in yuton were described. The chromatograms of yuton samples showed characteristic peaks of dimethyl esters of dicarboxylic acids, such as suberic and azelaic acids. Furthermore, it was revealed that these dicarboxylic acid components were originated from the network structures of oxidized perilla oil, based on thermochemolysis-GC measurements of yuton model samples. These results suggest that the network structures are also formed on the surface of yuton increasingly over prolonged periods of time, which in turn, give rise to its unique properties.

Lacquer is a natural material that has been used as a paint and adhesive in Japan since the Jomon period. Lacquer is a resin extracted from wood that hardens under a certain degree of warmth and humidity, forming a very strong coating film. This coating is insoluble in acids, bases, and organic solvents, making it very difficult to analyze. In the past 25 years, pyrolysis-gas chromatography/mass spectrometry (Py-GC/MS) has proven to be an effective method for the analysis of lacquer coatings. This paper describes basic Py-GC/MS analysis of lacquer and Py-GC/MS analysis of additives added to lacquer. Examples of analyses of specific excavated artifacts will also be presented.

An oil painting is one of popular cultural property containing drying oil. The author has analyzed color materials of paintings, textiles, color printed maps. Then under an aspect of conservation, the author had opportunities to realize conditions before restorations. The degradations of vehicles which bound to pigments each other were main causes. Drying oils form physically strong films but cracks, peeled pieces and protrusions appear due to aging. According to literature an extraction from linseeds to oils and purification processes were left the oil under ambient air and exposed to the sun for several weeks. Noteworthily, a solidification of oil color, which is also called drying processes, has a procedure of exposing to the sun. The procedure decolors an area of yellowing solid of the oil. A kind of drying promotor containing metal ion salt and petroleum solvent is brown solution. As a notable point the color of the promoter changes to colorless with the progress of the solidification. A saponification in a solidified oil has suggested a cause of the above-mentioned the degradations. The elucidation of the degradations was used a microscopic infrared spectrometer. Many models of oil paintings were analyzed to presume the conditions reproducing the degradations.