The Experts below are selected from a list of 312 Experts worldwide ranked by ideXlab platform
Tetsuo Miyakoshi - One of the best experts on this subject based on the ideXlab platform.
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application of pyrolysis comprehensive gas chromatography mass spectrometry for identification of asian Lacquers
Talanta, 2018Co-Authors: Shun Okamoto, Takayuki Honda, Tetsuo Miyakoshi, Bin Han, Michel SablierAbstract:A new approach based on online pyrolysis-comprehensive gas chromatography/mass spectrometry (Py-GCxGC/MS) is introduced for analysis of Lacquer saps with potential applications to analysis of Asian Lacquers. The bidimensional GCxGC separation demonstrated its benefits for characterization of the markers of Lacquer saps, alkylhydrocarbons, alkylbenzenes, alkylphenols, and alkylcatechols, in a visual way not attainable in monodimensional Py-GC/MS analysis. Moreover, the potentiality offered by GCxGC allows the separation of regioisomers difficult to obtain with a monodimensional separation. Under these circumstances, urushiol (Japanese, Chinese), laccol (Vietnamese), and thitsiol (Myanmar) Lacquer sap films were differentiated by their marker fingerprints with a limit of detection in the low μg range. Additionally, thermally assisted pyrolysis with tetramethylammonium hydroxyde (TMAH) clearly differentiated the alkylcatechol markers of the four Lacquer samples investigated, with a net separation of stereoisomers particularly well exemplified in the case of the Myanmar Lacquer sample. The proposed Py-GCxGC/MS approach greatly facilitates the analysis of Asian Lacquer saps, and is very promising for sensitive detection of Lacquers in archaeological artifacts.
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Application of pyrolysis-comprehensive gas chromatography/mass spectrometry for identification of Asian Lacquers
Talanta, 2018Co-Authors: Shun Okamoto, Takayuki Honda, Tetsuo Miyakoshi, Bin Han, Michel SablierAbstract:A new approach based on online pyrolysis-comprehensive gas chromatography/mass spectrometry (Py-GCxGC/MS) is introduced for analysis of Lacquer saps with potential applications to analysis of Asian Lacquers. The bidimensional GCxGC separation demonstrated its benefits for characterization of the markers of Lacquer saps, alkylhydrocarbons, alkylbenzenes, alkylphenols, and alkylcatechols, in a visual way not attainable in monodimensional Py-GC/MS analysis. Moreover, the potentiality offered by GCxGC allows the separation of regioisomers difficult to obtain with a monodimensional separation. Under these circumstances, urushiol (Japanese, Chinese), laccol (Vietnamese), and thitsiol (Myanmar) Lacquer sap films were differentiated by their marker fingerprints with a limit of detection in the low μg range. Additionally, thermally assisted pyrolysis with tetramethylammonium hydroxyde (TMAH) clearly differentiated the alkylcatechol markers of the four Lacquer samples investigated, with a net separation of stereoisomers particularly well exemplified in the case of the Myanmar Lacquer sample. The proposed Py-GCxGC/MS approach greatly facilitates the analysis of Asian Lacquer saps, and is very promising for sensitive detection of Lacquers in archaeological artifacts.
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identification of ryukyu Lacquerwares by pyrolysis gas chromatography mass spectrometry and 87sr 86sr isotope ratio
Journal of Analytical and Applied Pyrolysis, 2016Co-Authors: Takayuki Honda, Yoshimi Kamiya, Shun'ichi Nakai, Tetsuo MiyakoshiAbstract:Abstract Six pieces of Lacquer obtained from Ryukyu Lacquerwares produced in the 17–19th century in the Ryukyu Kingdom were analyzed by pyrolysis gas chromatography/mass spectrometry and 87Sr/86Sr isotope ratio measurements to determine the identity of the Lacquer source. The results were compared with the standard of natural Lacquer film to discriminate Lacquer species. Four pieces were made used Lacquer sap collected from Toxicodendron vernicifluum Lacquer tree, and other two pieces were made with Lacquer sap tapped from Toxicodendron succedanea Lacquer tree according to the characteristics of the pyrolysis products. All 87Sr/86Sr isotope values of urushiol Lacquerwares are over 0.71, suggesting that the origin of Lacquer trees were the Asian continent.
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Identification of Ryukyu Lacquerwares by pyrolysis-gas chromatography/mass spectrometry and 87Sr/86Sr isotope ratio
Journal of Analytical and Applied Pyrolysis, 2015Co-Authors: Takayuki Honda, Yoshimi Kamiya, Shun'ichi Nakai, Tetsuo MiyakoshiAbstract:Abstract Six pieces of Lacquer obtained from Ryukyu Lacquerwares produced in the 17–19th century in the Ryukyu Kingdom were analyzed by pyrolysis gas chromatography/mass spectrometry and 87Sr/86Sr isotope ratio measurements to determine the identity of the Lacquer source. The results were compared with the standard of natural Lacquer film to discriminate Lacquer species. Four pieces were made used Lacquer sap collected from Toxicodendron vernicifluum Lacquer tree, and other two pieces were made with Lacquer sap tapped from Toxicodendron succedanea Lacquer tree according to the characteristics of the pyrolysis products. All 87Sr/86Sr isotope values of urushiol Lacquerwares are over 0.71, suggesting that the origin of Lacquer trees were the Asian continent.
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Investigation of Ryukyu Lacquerwares by pyrolysis-gas chromatography/mass spectrometry☆
Journal of Analytical and Applied Pyrolysis, 2015Co-Authors: Takayuki Honda, Kunio Yoshida, Midori Yamabuki, Daisuke Ando, Masako Miyazato, Tetsuo MiyakoshiAbstract:Abstract Two pieces of Lacquer obtained from Ryukyu Lacquerwares produced in the 17–19th century in the Ryukyu Kingdom belonging to the Urasoe Art Museum were analyzed by pyrolysis-gas chromatography/mass spectrometry (Py-GC/MS). The results were compared with the standard of natural Lacquer film to determine the identity of the Lacquer species. Urushiol (MW = 320), 3-heptylcatechol (MW = 208), and 3-heptylphenol (MW = 192) were detected as pyrolysis products of Lacquer pieces of a Lacquer tray made by the hakue technique, suggesting that this Ryukyu Lacquerware was coated with Lacquer sap tapped from a Toxicodendron vernicifluum Lacquer tree. On the other hand, urushiol (MW = 320), 3-heptylcatechol (MW = 208), 3-heptylphenol (MW = 192), laccol (MW = 348), 3-nonylcatechol (MW = 236), and 3-nonylphenol (MW = 220) were detected as pyrolysis products of Lacquer pieces from a dinner tray made by the mitsuda-e technique, suggesting that this Ryukyu Lacquerware was coated with mixture Lacquer sap tapped from T. vernicifluum and Toxicodendron succedanea Lacquer trees, respectively. Moreover, microscopy and cross-section studies demonstrated that the Lacquers had a multi-layer structure. X-ray analytical microscopy was carried out directly on the surface of Lacquerwares to determine the presence of different pigments.
Takayuki Honda - One of the best experts on this subject based on the ideXlab platform.
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application of pyrolysis comprehensive gas chromatography mass spectrometry for identification of asian Lacquers
Talanta, 2018Co-Authors: Shun Okamoto, Takayuki Honda, Tetsuo Miyakoshi, Bin Han, Michel SablierAbstract:A new approach based on online pyrolysis-comprehensive gas chromatography/mass spectrometry (Py-GCxGC/MS) is introduced for analysis of Lacquer saps with potential applications to analysis of Asian Lacquers. The bidimensional GCxGC separation demonstrated its benefits for characterization of the markers of Lacquer saps, alkylhydrocarbons, alkylbenzenes, alkylphenols, and alkylcatechols, in a visual way not attainable in monodimensional Py-GC/MS analysis. Moreover, the potentiality offered by GCxGC allows the separation of regioisomers difficult to obtain with a monodimensional separation. Under these circumstances, urushiol (Japanese, Chinese), laccol (Vietnamese), and thitsiol (Myanmar) Lacquer sap films were differentiated by their marker fingerprints with a limit of detection in the low μg range. Additionally, thermally assisted pyrolysis with tetramethylammonium hydroxyde (TMAH) clearly differentiated the alkylcatechol markers of the four Lacquer samples investigated, with a net separation of stereoisomers particularly well exemplified in the case of the Myanmar Lacquer sample. The proposed Py-GCxGC/MS approach greatly facilitates the analysis of Asian Lacquer saps, and is very promising for sensitive detection of Lacquers in archaeological artifacts.
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Application of pyrolysis-comprehensive gas chromatography/mass spectrometry for identification of Asian Lacquers
Talanta, 2018Co-Authors: Shun Okamoto, Takayuki Honda, Tetsuo Miyakoshi, Bin Han, Michel SablierAbstract:A new approach based on online pyrolysis-comprehensive gas chromatography/mass spectrometry (Py-GCxGC/MS) is introduced for analysis of Lacquer saps with potential applications to analysis of Asian Lacquers. The bidimensional GCxGC separation demonstrated its benefits for characterization of the markers of Lacquer saps, alkylhydrocarbons, alkylbenzenes, alkylphenols, and alkylcatechols, in a visual way not attainable in monodimensional Py-GC/MS analysis. Moreover, the potentiality offered by GCxGC allows the separation of regioisomers difficult to obtain with a monodimensional separation. Under these circumstances, urushiol (Japanese, Chinese), laccol (Vietnamese), and thitsiol (Myanmar) Lacquer sap films were differentiated by their marker fingerprints with a limit of detection in the low μg range. Additionally, thermally assisted pyrolysis with tetramethylammonium hydroxyde (TMAH) clearly differentiated the alkylcatechol markers of the four Lacquer samples investigated, with a net separation of stereoisomers particularly well exemplified in the case of the Myanmar Lacquer sample. The proposed Py-GCxGC/MS approach greatly facilitates the analysis of Asian Lacquer saps, and is very promising for sensitive detection of Lacquers in archaeological artifacts.
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identification of ryukyu Lacquerwares by pyrolysis gas chromatography mass spectrometry and 87sr 86sr isotope ratio
Journal of Analytical and Applied Pyrolysis, 2016Co-Authors: Takayuki Honda, Yoshimi Kamiya, Shun'ichi Nakai, Tetsuo MiyakoshiAbstract:Abstract Six pieces of Lacquer obtained from Ryukyu Lacquerwares produced in the 17–19th century in the Ryukyu Kingdom were analyzed by pyrolysis gas chromatography/mass spectrometry and 87Sr/86Sr isotope ratio measurements to determine the identity of the Lacquer source. The results were compared with the standard of natural Lacquer film to discriminate Lacquer species. Four pieces were made used Lacquer sap collected from Toxicodendron vernicifluum Lacquer tree, and other two pieces were made with Lacquer sap tapped from Toxicodendron succedanea Lacquer tree according to the characteristics of the pyrolysis products. All 87Sr/86Sr isotope values of urushiol Lacquerwares are over 0.71, suggesting that the origin of Lacquer trees were the Asian continent.
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Identification of Ryukyu Lacquerwares by pyrolysis-gas chromatography/mass spectrometry and 87Sr/86Sr isotope ratio
Journal of Analytical and Applied Pyrolysis, 2015Co-Authors: Takayuki Honda, Yoshimi Kamiya, Shun'ichi Nakai, Tetsuo MiyakoshiAbstract:Abstract Six pieces of Lacquer obtained from Ryukyu Lacquerwares produced in the 17–19th century in the Ryukyu Kingdom were analyzed by pyrolysis gas chromatography/mass spectrometry and 87Sr/86Sr isotope ratio measurements to determine the identity of the Lacquer source. The results were compared with the standard of natural Lacquer film to discriminate Lacquer species. Four pieces were made used Lacquer sap collected from Toxicodendron vernicifluum Lacquer tree, and other two pieces were made with Lacquer sap tapped from Toxicodendron succedanea Lacquer tree according to the characteristics of the pyrolysis products. All 87Sr/86Sr isotope values of urushiol Lacquerwares are over 0.71, suggesting that the origin of Lacquer trees were the Asian continent.
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Investigation of Ryukyu Lacquerwares by pyrolysis-gas chromatography/mass spectrometry☆
Journal of Analytical and Applied Pyrolysis, 2015Co-Authors: Takayuki Honda, Kunio Yoshida, Midori Yamabuki, Daisuke Ando, Masako Miyazato, Tetsuo MiyakoshiAbstract:Abstract Two pieces of Lacquer obtained from Ryukyu Lacquerwares produced in the 17–19th century in the Ryukyu Kingdom belonging to the Urasoe Art Museum were analyzed by pyrolysis-gas chromatography/mass spectrometry (Py-GC/MS). The results were compared with the standard of natural Lacquer film to determine the identity of the Lacquer species. Urushiol (MW = 320), 3-heptylcatechol (MW = 208), and 3-heptylphenol (MW = 192) were detected as pyrolysis products of Lacquer pieces of a Lacquer tray made by the hakue technique, suggesting that this Ryukyu Lacquerware was coated with Lacquer sap tapped from a Toxicodendron vernicifluum Lacquer tree. On the other hand, urushiol (MW = 320), 3-heptylcatechol (MW = 208), 3-heptylphenol (MW = 192), laccol (MW = 348), 3-nonylcatechol (MW = 236), and 3-nonylphenol (MW = 220) were detected as pyrolysis products of Lacquer pieces from a dinner tray made by the mitsuda-e technique, suggesting that this Ryukyu Lacquerware was coated with mixture Lacquer sap tapped from T. vernicifluum and Toxicodendron succedanea Lacquer trees, respectively. Moreover, microscopy and cross-section studies demonstrated that the Lacquers had a multi-layer structure. X-ray analytical microscopy was carried out directly on the surface of Lacquerwares to determine the presence of different pigments.
Michel Sablier - One of the best experts on this subject based on the ideXlab platform.
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application of pyrolysis comprehensive gas chromatography mass spectrometry for identification of asian Lacquers
Talanta, 2018Co-Authors: Shun Okamoto, Takayuki Honda, Tetsuo Miyakoshi, Bin Han, Michel SablierAbstract:A new approach based on online pyrolysis-comprehensive gas chromatography/mass spectrometry (Py-GCxGC/MS) is introduced for analysis of Lacquer saps with potential applications to analysis of Asian Lacquers. The bidimensional GCxGC separation demonstrated its benefits for characterization of the markers of Lacquer saps, alkylhydrocarbons, alkylbenzenes, alkylphenols, and alkylcatechols, in a visual way not attainable in monodimensional Py-GC/MS analysis. Moreover, the potentiality offered by GCxGC allows the separation of regioisomers difficult to obtain with a monodimensional separation. Under these circumstances, urushiol (Japanese, Chinese), laccol (Vietnamese), and thitsiol (Myanmar) Lacquer sap films were differentiated by their marker fingerprints with a limit of detection in the low μg range. Additionally, thermally assisted pyrolysis with tetramethylammonium hydroxyde (TMAH) clearly differentiated the alkylcatechol markers of the four Lacquer samples investigated, with a net separation of stereoisomers particularly well exemplified in the case of the Myanmar Lacquer sample. The proposed Py-GCxGC/MS approach greatly facilitates the analysis of Asian Lacquer saps, and is very promising for sensitive detection of Lacquers in archaeological artifacts.
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Application of pyrolysis-comprehensive gas chromatography/mass spectrometry for identification of Asian Lacquers
Talanta, 2018Co-Authors: Shun Okamoto, Takayuki Honda, Tetsuo Miyakoshi, Bin Han, Michel SablierAbstract:A new approach based on online pyrolysis-comprehensive gas chromatography/mass spectrometry (Py-GCxGC/MS) is introduced for analysis of Lacquer saps with potential applications to analysis of Asian Lacquers. The bidimensional GCxGC separation demonstrated its benefits for characterization of the markers of Lacquer saps, alkylhydrocarbons, alkylbenzenes, alkylphenols, and alkylcatechols, in a visual way not attainable in monodimensional Py-GC/MS analysis. Moreover, the potentiality offered by GCxGC allows the separation of regioisomers difficult to obtain with a monodimensional separation. Under these circumstances, urushiol (Japanese, Chinese), laccol (Vietnamese), and thitsiol (Myanmar) Lacquer sap films were differentiated by their marker fingerprints with a limit of detection in the low μg range. Additionally, thermally assisted pyrolysis with tetramethylammonium hydroxyde (TMAH) clearly differentiated the alkylcatechol markers of the four Lacquer samples investigated, with a net separation of stereoisomers particularly well exemplified in the case of the Myanmar Lacquer sample. The proposed Py-GCxGC/MS approach greatly facilitates the analysis of Asian Lacquer saps, and is very promising for sensitive detection of Lacquers in archaeological artifacts.
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Alteration of Asian Lacquer: in-depth insight using a physico-chemical multiscale approach
Analyst, 2013Co-Authors: Chloé Duhamel, Michel Sablier, Céline Daher, Ludovic Bellot-gurlet, Céline Paris, Martine Regert, Guilhem André, Paul Desroches, Paul DumasAbstract:Oriental Lacquer has been used in Asian countries for thousands of years as a durable and aesthetic coating material for its adhesive, consolidating, protective and decorative properties. Although these objects are made from an unusual material in Occident, Western museum collections host many Lacquerwares. Curators, restorers and scientists are daily confronted with questions of their conservation and their alteration. The characterization of their conservation state is usually assessed through visual observations. However deterioration often starts at the microscopic level and cannot be detected by a simple visual inspection. Often, ageing and deterioration of artworks are connected to physical, mechanical and chemical transformations. Thus new insight into alteration of Lacquer involves the monitoring of macro-, microscopic and molecular modifications, and this can be assessed from physico-chemical measurements. Non-invasive (microtopography and Scanning Electron Microscopy – SEM) and micro-invasive (infrared micro-spectroscopy using a synchrotron source – SR-mFTIR) investigations were performed to study the degradation processes of Lacquers and evaluate their level of alteration. In particular, spectral decomposition and fitting procedure were performed in the 1820–1520 cm À1 region to follow the shift of the C]O and C]C band positions during Lacquer ageing. The present work proves the potential of this physico-chemical approach in conservation studies of Lacquers and in the quantification of the state of alteration. It evidences chemical phenomena of alteration such as oxidation and decomposition of a Lacquer polymeric network. It also demonstrates for the first time the degradation front of artificially aged Lacquer and the chemical imaging of a more than 2000 years old archaeological Lacquer by using SR-mFTIR.
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molecular criteria for discriminating museum asian Lacquerware from different vegetal origins by pyrolysis gas chromatography mass spectrometry
Analytica Chimica Acta, 2012Co-Authors: Martine Regert, Tetsuo Miyakoshi, Chloé Duhamel, Olivier Marescot, Juliette Langlois, Christophe Genty, Michel SablierAbstract:This paper focuses on the identification of several chemical markers of vegetal species of Oriental Lacquers with the aim at providing a methodology consistent with sampling restrictions necessarily applied in the field of cultural heritage. The method proposed is based on rapid and easy single step thermally assisted hydrolysis-methylation (THM) pyrolysis-gas chromatography/mass spectrometry (Py-GC/MS) analysis that can be carried out with a minimum amount of matter (typically 10 μg for a sample collected on a museum or an archaeological object). The main contribution of this study is to provide multiple molecular criteria for discriminating the three Asian species used for making Lacquers, namely Rhus verniciflua Stokes, Rhus succedanea and Melanorrhoea usitata. Because these trees grow in specific areas, identifying the species involved in ancient Lacquer coatings also provides geobotanical data and fruitful information on the exchange networks and trading routes developed by ancient societies. With this purpose, a systematic study of all pyrolysis products of Lacquer coatings was carried out on modern dried Lacquer films from authentified provenance. It was demonstrated that the whole pyrolysis products play a significant role in identifying the vegetal species. The chemotaxonomic value of homologous series of alkanes, alkenes and benzene derivatives, rarely explored until now, was assessed. It was shown that the combination of data related to five distinct groups of pyrolytic markers (composition and/or distribution of alkanes, alkenes and benzene, alkenyl-, alkylcatechol and phenol derivatives) provided new strong criteria to establish vegetal origin and provenance of Asian artworks, even though they have been largely altered over time. Case studies of archaeological Chinese Lacquered artefacts and Japanese Buddhistic altar were thereafter successfully investigated to address informative potential and efficiency of these criteria on ancient and degraded Lacquer coatings.
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Molecular criteria for discriminating museum Asian Lacquerware from different vegetal origins by pyrolysis gas chromatography/mass spectrometry.
Analytica Chimica Acta, 2012Co-Authors: M. Regert, Olivier Marescot, Juliette Langlois, Christophe Genty, C. Duhamel, T. Miyakoshi, Michel SablierAbstract:This paper focuses on the identification of several chemical markers of vegetal species of Oriental Lacquers with the aim at providing a methodology consistent with sampling restrictions necessarily applied in the field of cultural heritage. The method proposed is based on rapid and easy single step thermally assisted hydrolysis-methylation (THM) pyrolysis-gas chromatography/mass spectrometry (Py-GC/MS) analysis that can be carried out with a minimum amount of matter (typically 10 μg for a sample collected on a museum or an archaeological object). The main contribution of this study is to provide multiple molecular criteria for discriminating the three Asian species used for making Lacquers, namely Rhus verniciflua Stokes, Rhus succedanea and Melanorrhoea usitata. Because these trees grow in specific areas, identifying the species involved in ancient Lacquer coatings also provides geobotanical data and fruitful information on the exchange networks and trading routes developed by ancient societies. With this purpose, a systematic study of all pyrolysis products of Lacquer coatings was carried out on modern dried Lacquer films from authentified provenance. It was demonstrated that the whole pyrolysis products play a significant role in identifying the vegetal species. The chemotaxonomic value of homologous series of alkanes, alkenes and benzene derivatives, rarely explored until now, was assessed. It was shown that the combination of data related to five distinct groups of pyrolytic markers (composition and/or distribution of alkanes, alkenes and benzene, alkenyl-, alkylcatechol and phenol derivatives) provided new strong criteria to establish vegetal origin and provenance of Asian artworks, even though they have been largely altered over time. Case studies of archaeological Chinese Lacquered artefacts and Japanese Buddhistic altar were thereafter successfully investigated to address informative potential and efficiency of these criteria on ancient and degraded Lacquer coatings. Copyright © 2011 Elsevier B.V. All rights reserved.
Tetsuo Higuchi - One of the best experts on this subject based on the ideXlab platform.
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IDENTIFICATION OF ANCIENT Lacquer FILM USING TWO-STAGE PYROLYSIS-GAS CHROMATOGRAPHY/MASS SPECTROMETRY*
Archaeometry, 1999Co-Authors: Noriyasu Niimura, Tetsuo Miyakoshi, Jun Onodera, Tetsuo HiguchiAbstract:Oriental Lacquer has been used as a surface coating for wood, porcelain and metal, and three different types are known: Japanese (or Chinese) Lacquer (urushiol-based), Vietnamese Lacquer (laccol-based) and Burmese Lacquer (thitsiol-based). Identification of these types in ancient coatings is very important in conservation and restoration studies. A two-stage pyrolysis-gas chromatography/mass spectrometry method is effective for the analysis of Lacquer films. This is shown here using an ancient Lacquer film sample from medieval material excavated at Tobarikyu (Japan), The sample was identified, by comparison with linseed oil and authentic Lacquer films, as an urushiol-based Rhus vernicifera (Japanese) Lacquer which includes an added oil component.
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characterization of rhus vernicifera and rhus succedanea Lacquer films and their pyrolysis mechanisms studied using two stage pyrolysis gas chromatography mass spectrometry
Journal of Analytical and Applied Pyrolysis, 1996Co-Authors: Noriyasu Niimura, Tetsuo Miyakoshi, Jun Onodera, Tetsuo HiguchiAbstract:Abstract Rhus vernicifera and Rhus succedanea Lacquers, which are used as a surface coating for wood, porcelain and metalware in Japan, were investigated using two-stage pyrolysis gas chromatography/mass spectrometry (Py-GC/MS). Urushiol and laccol components were detected in each Lacquer film by pyrolysis at 400 °C. These are the monomers, and are characteristic of Rhus vernicifera and Rhus succedanea Lacquer films. In addition, alkenes, alkanes, alkenylphenols and alkylphenols were detected by pyrolysis at 500 °C after pyrolysis at 400 °C. Based on these results, the pyrolysis mechanisms of the respective Lacquer films were considered. The pyrolysis products were from the urushiol and laccol polymers. These pyrolysis products clearly reflect the structure of each Lacquer film.
Noriyasu Niimura - One of the best experts on this subject based on the ideXlab platform.
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Determination of the type of Lacquer on East Asian Lacquer ware
International Journal of Mass Spectrometry, 2009Co-Authors: Noriyasu NiimuraAbstract:Abstract Simple and easy analytical methods, which are applicable to precious artistic objects, have long been desired to determine the type of Lacquer on Lacquer ware. Direct inlet mass spectrometry (DIMS) and pyrolysis-gas chromatography/mass spectrometry (Py-GC/MS) were applied to the determination of the coating film on a Lacquered wooden dish obtained in Okinawa. The above two-step mass spectrometry confirmed the coating film: the Lacquer to be East Asian Lacquer, or natural urushi derived from Rhus verniciflua . These two-step analyses are very useful for the determination of the type of Lacquer on any Lacquer ware. The first step analysis with DIMS is used to distinguish the natural urushi including the urushi-type Lacquers from non-natural urushi: imitation urushi and Lacquer containing synthetic resins. And the second step with Py-GC/MS is used to discriminate one type among the three natural urushi-type Lacquers. These two-step analyses need only a small amount of sample ranging 0.01–0.5 mg without any pre-treatment so that these analyses can be used for precious Lacquer ware with archeological interest.
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Characterization of Natural Resin Films and Identification of Ancient Coating
Journal of the Mass Spectrometry Society of Japan, 2003Co-Authors: Noriyasu Niimura, Tetsuo MiyakoshiAbstract:Typical Japanese natural resin films, i.e., oriental Lacquer films, cashew resin films, and drying oil polymers were characterized, and also an ancient coating was identified using two-stage pyrolysis-gas chromatography/mass spectrometry (Py-GC/MS). Urushiol, laccol, and thitsiol components, which are the main constituents of the respective oriental Lacquers, were detected by the pyrolysis at 400°C. Additionally, the pyrolysis products, which reflect the structure of the urushiol, laccol, and thitsiol polymers, were detected by pyrolysis at 500°C after pyrolysis at 400°C. All the results have shown a significant progress occurring in the side chain-side chain C-C coupling and aromatic nucleus-side chain C-O coupling of urushiol, laccol, and thitsiol concurrently with the formation of the respective Lacquer films. The cashew resin film was found to be terminated with saturated cardols and cardanols by the pyrolysis at 400°C. Furthermore, pyrolysis at 500°C revealed that the autoxidative side chain-side chain C-C coupling accelerated the cross-linking of trienyl- and dienylcardanols during the polymerization. The C4-C18 free fatty acids were detected by the pyrolysis of the drying oil polymers. These pyrolysis products are significant markers for a drying oil polymer. The drying oil polymer is terminated with saturated fatty acids, especially with hexadecanoic acid and octadecanoic acid. Based on these results, the ancient coating sample obtained from the surface of a wooden dish excavated at Tobarikyu, Kyoto prefecture, Japan was identified as Rhus vernicifera Lacquer combined with an drying oil, presumably added as the solvent. Py-GC/MS was proved to be effective for the characterization of natural resin films and identification of organic coatings of historic artifacts.
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IDENTIFICATION OF ANCIENT Lacquer FILM USING TWO-STAGE PYROLYSIS-GAS CHROMATOGRAPHY/MASS SPECTROMETRY*
Archaeometry, 1999Co-Authors: Noriyasu Niimura, Tetsuo Miyakoshi, Jun Onodera, Tetsuo HiguchiAbstract:Oriental Lacquer has been used as a surface coating for wood, porcelain and metal, and three different types are known: Japanese (or Chinese) Lacquer (urushiol-based), Vietnamese Lacquer (laccol-based) and Burmese Lacquer (thitsiol-based). Identification of these types in ancient coatings is very important in conservation and restoration studies. A two-stage pyrolysis-gas chromatography/mass spectrometry method is effective for the analysis of Lacquer films. This is shown here using an ancient Lacquer film sample from medieval material excavated at Tobarikyu (Japan), The sample was identified, by comparison with linseed oil and authentic Lacquer films, as an urushiol-based Rhus vernicifera (Japanese) Lacquer which includes an added oil component.
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characterization of rhus vernicifera and rhus succedanea Lacquer films and their pyrolysis mechanisms studied using two stage pyrolysis gas chromatography mass spectrometry
Journal of Analytical and Applied Pyrolysis, 1996Co-Authors: Noriyasu Niimura, Tetsuo Miyakoshi, Jun Onodera, Tetsuo HiguchiAbstract:Abstract Rhus vernicifera and Rhus succedanea Lacquers, which are used as a surface coating for wood, porcelain and metalware in Japan, were investigated using two-stage pyrolysis gas chromatography/mass spectrometry (Py-GC/MS). Urushiol and laccol components were detected in each Lacquer film by pyrolysis at 400 °C. These are the monomers, and are characteristic of Rhus vernicifera and Rhus succedanea Lacquer films. In addition, alkenes, alkanes, alkenylphenols and alkylphenols were detected by pyrolysis at 500 °C after pyrolysis at 400 °C. Based on these results, the pyrolysis mechanisms of the respective Lacquer films were considered. The pyrolysis products were from the urushiol and laccol polymers. These pyrolysis products clearly reflect the structure of each Lacquer film.
