• Analytical Science and Technology
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• v.31 no.2
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• pp.78-87
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• 2018

Asian lacquer has been used as an adhesive and coating material in Asian countries, such as China, Japan, and Korea, and other southeast Asian countries. In this study, the changes in the chemical structure of lacquer with drying was analyzed using pyrolysis/GC/MS (which is useful in analyzing polymeric material) to understand its drying procedures. Upon increasing temperature, the dried lacquer was fully pyrolyzed above the pyrolysis temperature of $500^{\circ}C$. The repeatability was good at the pyrolysis temperature of $500^{\circ}C$ (rsd = 2.6-22.3 %); however, there were differences in the pyrogram patterns when the difference in sample quantity was large. The characteristic peaks of Asian lacquer components, such as those corresponding to 1,2-benzenediol and 3-methyl-1,2-benzenediol, were detected and the compound of each peak was assigned according to the mass library. As the lacquer dried, the composition of pyrolysis products with urushiol derivatives bearing 3 C=C bonds was severely reduced compared with the ones with no C=C bonds, indicating that the polymerization is related to C=C bonds. These results can be applied to confirm the presence of lacquer in excavated relics and to monitor the changes in the composition of raw lacquer with drying.

• Journal of Conservation Science
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• v.36 no.2
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• pp.103-111
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• 2020

To compare the cleaning effect of solvents such as water and ethanol used to clean lacquer relics, the components extracted with various solvents were analyzed. A freshly dried lacquer sample and a lacquer sample exposed to ultraviolet radiation for 24 days were treated with water, ethanol, acetone, and hexane, and the dissolved material was detected by pyrolysis-gas chromatography-mass spectrometry. The amount extracted was significantly higher in acetone and ethanol than in hexane, a nonpolar solvent. Water, a highly polar solvent, was relatively efficient for extracting low-molecular-weight materials. After experiencing 24 days of ultraviolet radiation, the lacquer exhibited a significant increase of extracted materials compared with the nonexposed one. This may be due to the degradation of the urushiol chain in the form of polymers, resulting in the formation of low-molecular-weight polar substances, including dicarboxylic acids. In addition to the deterioration status of lacquer relics, such solvent extraction properties will be a crucial consideration in selecting the appropriate cleaning solvent.

• Journal of Conservation Science
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• v.34 no.5
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• pp.369-377
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• 2018

In order to examine the constituents and weathered state of a lacquer specimen, analysis of the organic materials was conducted using py/GC/MS(pyrolysis-gas chromatography-mass spectrometry). The samples were obtained from the lacquered wooden sheath of a long ring-pommel sword excavated in the Imdang No.1 ancient tomb constructed around the Proto-Three Kingdoms period. In direct py/GC/MS, the sample and the dried Asian lacquer showed similar chromatograms, while the characteristic compounds of Asian lacquer such as 1,2-dimethoxy-3-pentadecylbenzene were observed in THM(thermally assisted hydrolysis and methylation)-py/GC/MS. In addition, compounds like dimethyl nonanedioate, which presumably originated from drying oil, were also detected. Furthermore, the detection of oxidized catechols in considerable amount indicated that the degradation of lacquer is estimated to result from the oxidation of urushiol. Therefore, it is suggested that the lacquered wooden sheath was prepared using Asian lacquer and drying oil, and that the lacquer layer was considerably oxidized over the long burial time.

• Journal of Conservation Science
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• v.33 no.5
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• pp.345-354
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• 2017

A mural was discovered in the Ssanggyesa temple located in Jindo island, during repair of the Daeungjeon Hall. A study was conducted to determine the binding medium used for preparing the mural. Pyrolysis/GC/MS and IR spectrometry were used to analyze a painting specimen. Direct approach and on-line methylation approach were attempted for the pyrolysis/GC/MS. In IR analysis, the spectra of the specimen were found to be different from those of Asian lacquer, yellow lacquer, animal glue, and acrylic emulsion resin. They were also not identical to the standard IR spectra of drying oils such as linseed oil. Pyrolysis/GC/MS results of the specimen were different from those of Asian lacquer, yellow lacquer, animal glue, and acrylic emulsion resin. In the mean time, palmitic acid, octadecanoic acid, nonanedioic acid, and octadecenoic acid, which are characteristic pyrolysis products of dried drying oil, were detected. In addition, the pyrolysis/GC/MS chromatograms of the specimen and dried drying oil were also very similar. Therefore, it was concluded that the painting was prepared using drying oil as a binding medium.

• Journal of the East Asian Society of Dietary Life
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• v.25 no.4
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• pp.574-593
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• 2015

This research's main objective was to analyze the special qualities of food culture of the Main Family in Chung-Buk through a case study on the diversified types of meals that the Main Family cooked, such as courtesy food, normal food, and seasonal food. The research identifies traditional ingredients of specialties from Chung-Buk through old literature. According to "Sejongsillokjiriji", there are a myriad of ingredients:, including jujube, ginseng, pine mushroom, manna lichen, persimmon, mandarin fish, crab, sweetfish, lacquer, honey, and terrapin, which represent Chung-Buk's unique ingredients. Another reliable source, "Banchandungsok", does not provide a detailed list of traditional foods, but rather a simple list. The majority of food from Chung-Buk, in "Banchandungsok", consist of side dishes like kimchi and salt greens. Eventually, salt greens became diversified. As Chung-Buk is a landlocked province, people often used dried pollack. Kimchi and raw coaker were frequently used as well, and rice cakes encompassed multiple ingredients such as: jujube, mushroom, pine nut, and, dried persimmon. There were distinct differences in the diversity of food and amount of dishes used by the Main Families of Chung-Buk dependent on the ingredients and wealth of each Main Family. Chung-Buk has a landscape full of mountains, so potatoes were abundant and used to make potato Dasik. When cooking process was completed, people placed kelp on to the finished product. Seasonal foods were considered very important, especially on special occasions such as Backjoong, which was a day dedicated to laborers. These foodsprovided a good opportunity for the community to build stronger bonds by sharing rice cake and Yukgaejang with other members of the community. It is apparent that "Jeobbingac" culture, or guest culture, flourished since people in Chung-Buk are traditionally taught to leave spare food for the guest at all times.