Cattersel, Vincent

Decq, Louise

Fremout, Wim

Indekeu, Charles

Lynen, Frederic

Saverwyns, Steven

Schilling, Michael

Steyaert, Delphine

Van Binnebeke, Emile

English

Ghent University Academic Bibliography

BLK0030venetianturpentine_rerun 27/11/2014 16:13:561µl tmah + 1 µl IS - cup 6 J3RT: 4.03 - 39.025 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39Time (min)0102030405060708090100Relative AbundanceNL:7.94E7TIC F:   MS BLK0030venetianturpentine_rerunFrom the results, it is clear that pyrolysis at fixed temperature of 650°C is not desirable. Many of the selected markers are not or less visible with pyrolysis at this temperature. This temperature program will be left out in the further discussion. When comparing the intensity of a peak at the remaining temperature programs, three groups can be discerned. A first group of markers (  ) performs well at all remaining temperature programs (UFD, 350, 480, 550°C). Differences between them are minimal. A second group of markers (  ) shows a slight or important trend in favor of low temperatures; these tend to decrease in intensity or disappear at high temperatures. For these molecules, a temperature of 350°C, is preferable. As expected, UFD performs also very well for these molecules. 480°C is a less performing option, but can be esteemed acceptable.   A third group comprises molecules that tend to be more present when high temperatures are applied (+). These molecules are best detected with a fixed pyrolysis temperature of 550°C. A fixed temperature of 480°C performs well. Remarkably, UFD does not reach the expectations: for these molecules, UFD shows overall lower signal strength than when 480°C pyrolysis temperature was applied. Some molecules may not be formed because their precursors left the oven earlier, or other side reactions may take place. Louise Decq1,2, Vincent Cattersel3, Delphine Steyaert4, Michael Schilling5, Frederic Lynen2, Charles Indekeu3, Emile Van Binnebeke4, Wim Fremout1 and Steven Saverwyns1  1Royal Institute for Cultural Heritage (KIK/IRPA) ● Laboratories Department ● Jubelpark 1 ● 1000 Brussels ● Belgium 2Ghent University (UGent) ● Department of Organic Chemistry ● Krijgslaan 281 ● 9000 Ghent ● Belgium  3University of Antwerp (UA) ● Conservation studies ● Blindestraat 9 ● 2000 Antwerp ● Belgium 4Royal Museums of Art and History (KMKG/MRAH) ● Jubelpark 10 ● 1000 Brussels ● Belgium  5Getty Conservation Institute (GCI) ● 1200 Getty Center Drive ● Suite 700 ● Los Angeles ● CA 90049-1684 ● USA Louise.Decq@kikirpa.be ● +32 (0)2 739 68 42 ● org.kikirpa.be/elinc Oriental lacquer came into vogue in Europe starting from the 16th century. Its immense popularity stimulated craftsmen to imitate these luxury items, using their own familiar materials and techniques. European lacquers are complex, multi-layered coatings, mainly composed of various natural resins. The European Lacquer in Context project focuses on the historical, chemical, physical and technological study of European lacquers*. During this project, historical objects are analyzed and European lacquer is reconstructed following historical recipes and studied after artificial aging. Gas chromatography/mass spectrometry with thermally-assisted hydrolysis and methylation (THM-GC/MS) was chosen as primary method for the analysis of the pure basic materials, lacquer reconstructions and historical lacquered items. During this study, pyrolysis temperature was optimized for gathering of maximal information on the compounds present in five terpenoid plant resins, all important ingredients for European lacquer: sandarac, mastic, colophony, Manila copal and Congo copal.  Methods Optimisation of pyrolysis temperature for chromatographic analysis of natural resins Introduction For each resin, five temperature programs were tested: four fixed temperatures (350°C, 480°C, 550°C, 650°C) and one ultrafast thermal desorption (UFD; 350-660°C). In the latter, the sample falls into the oven at 350°C, and is consequently heated to 660°C within one minute. The idea of this method is that easily volatilized compounds can escape the oven before possibly being destroyed at high temperatures. When temperatures rise, more compounds are set free and gathered on the cool column. It was therefore expected, in theory, that this temperature program should be the best compromise between a fixed low or high temperature, while degradation products of compounds released at low temperatures are avoided. Each resin-temperature combination was repeated three times.  020000000400000006000000080000000100000000120000000140000000160000000350 UFD (350-660°C) 480°C 550°C 650°CThe experiment illustrates the important influence of pyrolysis temperature on the signal strength of several resin markers. The optimal temperature depends on the molecules of interest. However, fixed temperatures of 550°C and 650°C are not ideal as consensus temperature. 350°C could be considered, but fixed temperature of 480°C or UFD gives best results in detecting the whole series of marker molecules.   In general, differences between these two options are limited; UFD performs better for heat sensitive compounds that are released at low temperatures (e.g. 350°C), whereas 480°C is generally a better choice for compounds formed at high temperatures, best seen at 550°C.  The authors acknowledge the institutions for facilitating access to their resin collections and/or for providing resin reference samples: Botanic Garden Meise (Viviane Leyman), Museum for Middle Africa Tervuren (Hans Beeckman), Hochschule für Bildende Künste of Dresden (Annegret Fuhrman).   The research leading to these results has been subsidized by the Belgian Science Policy Office through the contract no. BR / 121 / A3 / ELINC within the BRAIN project European Lacquer in Context (ELinC).  * V. Cattersel, L. Decq, C. Indekeu, E. Van Binnebeke, D. Steyaert, W. Fremout, S. Saverwyns. 2015. European Lacquer in Context, an interdisciplinary and systematic approach to the study of the tradition of European lacquering. Pp 56-62, in: Furniture Finishes (Miko Vasques Dias ,ed.), Stichting Ebenist, Amsterdam. sandarac mastic colophony Manila copal Congo copal                                                                    +  +  +  +  +  +  +  +  Conclusions Results and discussion        Acknowledgements From the results, it is clear that pyrolysis at fixed temperature of 650°C is not desirable. Many of the selected markers are not or less visible with pyrolysis at this temperature. This temperature program will be left out in the further discussion. When comparing the intensity of a peak at the remaining temperature programs, three groups can be discerned. A first group of markers (  ) performs well at all remaining temperature programs (UFD, 350, 480, 550°C). Differences between them are minimal. A second group of markers (  ) shows a slight or important trend in favor of low temperatures; these tend to decrease in intensity or disappear at high temperatures. For these molecules, a temperature of 350°C, is preferable. As expected, UFD performs also very well for these molecules. 480°C is a less performing option, but can be esteemed acceptable.   A third group comprises molecules that tend to be more present when high temperatures are applied (+). These molecules are best detected with a fixed pyrolysis temperature of 550°C. A fixed temperature of 480°C performs well. Remarkably, UFD does not reach the expectations: for these molecules, UFD shows overall lower signal strength than when 480°C pyrolysis temperature was applied. Some molecules may not be formed because their precursors left the oven earlier, or other side reactions may take place. Louise Decq1,2, Vincent Cattersel3, Delphine Steyaert4, Michael Schilling5, Frederic Lynen2, Charles Indekeu3, Emile Van Binnebeke4, Wim Fremout1 and Steven Saverwyns1  1Royal Institute for Cultural Heritage (KIK/IRPA) ● Laboratories Department ● Jubelpark 1 ● 1000 Brussels ● Belgium 2Ghent University (UGent) ● Department of Organic Chemistry ● Krijgslaan 281 ● 9000 Ghent ● Belgium  3University of Antwerp (UA) ● Conservation studies ● Blindestraat 9 ● 2000 Antwerp ● Belgium 4Royal Museums of Art and History (KMKG/MRAH) ● Jubelpark 10 ● 1000 Brussels ● Belgium  5Getty Conservation Institute (GCI) ● 1200 Getty Center Drive ● Suite 700 ● Los Angeles ● CA 90049-1684 ● USA Louise.Decq@kikirpa.be ● +32 (0)2 739 68 42 ● org.kikirpa.be/elinc Oriental lacquer came into vogue in Europe starting from the 16th century. Its immense popularity stimulated craftsmen to imitate these luxury items, using their own familiar materials and techniques. European lacquers are complex, multi-layered coatings, mainly composed of various natural resins. The European Lacquer in Context project focuses on the historical, chemical, physical and technological study of European lacquers*. During this project, historical objects are analyzed and European lacquer is reconstructed following historical recipes and studied after artificial aging. Gas chromatography/mass spectrometry with thermally-assisted hydrolysis and methylation (THM-GC/MS) was chosen as primary method for the analysis of the pure basic materials, lacquer reconstructions and historical lacquered items. During this study, pyrolysis temperature was optimized for gathering of maximal information on the compounds present in five terpenoid plant resins, all important ingredients for European lacquer: sandarac, mastic, colophony, Manila copal and Congo copal.  Methods Optimisation of pyrolysis temperature for chromatographic analysis of natural resins Introduction For each resin, five temperature programs were tested: four fixed temperatures (350°C, 480°C, 550°C, 650°C) and one ultrafast thermal desorption (UFD; 350-660°C). In the latter, the sample falls into the oven at 350°C, and is consequently heated to 660°C within one minute. The idea of this method is that easily volatilized compounds can escape the oven before possibly being destroyed at high temperatures. When temperatures rise, more compounds are set free and gathered on the cool column. It was therefore expected, in theory, that this temperature program should be the best compromise between a fixed low or high temperature, while degradation products of compounds released at low temperatures are avoided. Each resin-temperature combination was repeated three times.  020000000400000006000000080000000100000000120000000140000000160000000350 UFD (350-660°C) 480°C 550°C 650°CThe experiment illustrates the important influence of pyrolysis temperature on the signal strength of several resin markers. The optimal temperature depends on the molecules of interest. However, fixed temperatures of 550°C and 650°C are not ideal as consensus temperature. 350°C could be considered, but fixed temperature of 480°C or UFD gives best results in detecting the whole series of marker molecules.   In general, differences between these two options are limited; UFD performs better for heat sensitive compounds that are released at low temperatures (e.g. 350°C), whereas 480°C is generally a better choice for compounds formed at high temperatures, best seen at 550°C.  The authors acknowledge the institutions for facilitating access to their resin collections and/or for providing resin reference samples: Botanic Garden Meise (Viviane Leyman), Museum for Middle Africa Tervuren (Hans Beeckman), Hochschule für Bildende Künste of Dresden (Annegret Fuhrman).   The research leading to these results has been subsidized by the Belgian Science Policy Office through the contract no. BR / 121 / A3 / ELINC within the BRAIN project European Lacquer in Context (ELinC).  * V. Cattersel, L. Decq, C. Indekeu, E. Van Binnebeke, D. Steyaert, W. Fremout, S. Saverwyns. 2015. European Lacquer in Context, an interdisciplinary and systematic approach to the study of the tradition of European lacquering. Pp 56-62, in: Furniture Finishes (Miko Vasques Dias ,ed.), Stichting Ebenist, Amsterdam. sandarac mastic colophony Manila copal Congo copal                                                                    +  +  +  +  +  +  +  +  Conclusions Results and discussion        Acknowledgements BLK0030venetianturpentine_rerun 27/11/2014 16:13:561µl tmah + 1 µl IS - cup 6 J3RT: 4.03 - 39.025 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39Time (min)0102030405060708090100Relative AbundanceNL:7.94E7TIC F:   MS BLK0030venetianturpentine_rerun

Optimisation of pyrolysis temperature for chromatographic analysis of natural resins

https://biblio.ugent.be/publication/8569460/file/8590873.pdf

Optimisation of pyrolysis temperature for chromatographic analysis of natural resins

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Ghent University Academic Bibliography