Dammar resin pyrolysis

In addition to GC/MS, high performance liquid chromatography (HPLC/MS) has been used to analyse natural resins in ancient samples, particularly for paint varnishes containing mastic and dammar resins [34]. A partial limitation of chromatographic techniques is that they do not permit the analysis of the polymeric fraction or insoluble fraction that may be present in the native resins or formed in the course of ageing. Techniques based on the direct introduction of the sample in the mass spectrometer such as direct temperature resolved mass spectrometry (DTMS), direct exposure mass spectrometry (DE-MS) and direct inlet mass spectrometry (DI-MS), and on analytical pyrolysis (Py-GC/MS), have been employed as complementary techniques to obtain preliminary information on the... 

The reproducibility of the results for heated filament pyrolysers (CDS Pyroprobe 1000) and Curie point pyrolysers (Horizon Instruments) was reported for several samples [34]. This included several synthetic polymers, dammar resin, chitin, an insect cuticle, a hardwood (cherry), a seed coat (water lily), lycopod cuticle (fossil Eskdalia), as well as several organic geological samples. All samples were pyrolysed at 610° C for 5 s in a flow of helium. The residence time in the pyrolyser before pyrolysis was kept constant and the temperature of the sample housing was 250° C. Other parameters such as the temperature of the transfer line to the analytical instrument were also the same. Both systems were connected to a GC/MS system for the pyrolysates analysis. 

Feller, K.L., Dammar and mastic infrared analysis. Science, 120 1069-1070 (1954). Shedrinsky, A.M., D. Grimaldi, T.R Wampler, and N.S. Baer, Amber and copal pyrolysis gas chromatographic (PyGC) studies of prevenance, Wiener Berichte fiber Naturwissenschaft in der Kunst, 6niS (1989/90/91), pp. 37—62. van Aarssen, B.G.K., J.W. de Leeuw, and B. Horsfield, A comparative study of three different pyrolysis methods used to characterize a biopolymer isolated from fossil and extant dammar resins, J. Anal. Appl. PyroL, 20 125-139 (1991). 

Other polymeric terpenes are also known in nature. One such material is the resin called dammar (recent or fossil), generated by the trees from the family Dipterocarpaceae. Pyrolytic studies were performed on this polymer [16] after separation in two fractions, one soluble in CH2CI2 and the other insoluble. Three different pyrolysis techniques were used to obtain information on the insoluble polymer, flash pyrolysis, open isothermal furnace pyrolysis and closed system isothermal pyrolysis. Several compounds separated and identified in pyrolysates by GC/MS are shown below ... 

Analytical pyrolysis has been proven a very useful tool in the identification of resins used for artistic objects [16,17], The pyrograms of Manila copal, colophony, Venice turpentine, elemi, shellac, dammar, sandarac, and mastic were obtained and used as fingerprints for these materials. Manila copal, colophony, and Venice turpentine were characterized by the presence of a degradation compound from abietic acid (as the source of these resins is from species of Coniferae), probably methyl-isopropylnaphthalene. Elemi has a characteristic peak for elemicine, shellac showed a series of fatty acids, dammar showed the presence of sesquiterpenes (see Section 6.3), sandarac was characterized by a phenolic compound, totarol, and mastic was also identified by specific sesquiterpenes [17]. 

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