Analytical pyrolysis

Pyrolysis of a polymer means thermal degradation in the complete absence of any external reactant. Analytical pyrolysis, defined as pyrolysis conducted in combina- 

Examples of the use of Py-MS or Py-GC-MS for the characterization of mutants in which lignin biosynthesis was disrupted can be found in Vermerris and Boon (2001) and Bout and Vermerris (2003), whereas Fontaine et al. (2003) used Py-GC-MS to investigate the chemical basis of forage quality. 

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Modern analytical pyrolysis has conventionally been canied out only by thermal energy to break some covalent bonds in the sample molecules at elevated temperatures to produce smaller and/or volatile fragments (pyrolyzates). On the other hand, the reactive pyrolysis in the presence of organic alkaline, such as tetramethylammonium hydroxide [(CH / NOH] (TMAH) has recently received much attention especially in the field of chai acterizing condensation polymers. 

After brief discussion of the state-of-the-art of modern Py-GC/MS, some most recent applications for stixictural and compositional chai acterization of polymeric materials are described in detail. These include microstixictural studies on sequence distributions of copolymers, stereoregularity and end group chai acterization for various vinyl-type polymers such as polystyrene and polymethyl methacrylate by use of conventional analytical pyrolysis. 

Analytical Pyrolysis A Comprehensive Guide, William J. Irwin... 

R. Goodacre, Characterisation and quantification of microbial systems using pyrolysis mass spectrometry introducing neural networks to analytical pyrolysis, Microbiol. (Europe), 2 19 (1994). 

W. J. Irwin, "Analytical Pyrolysis A Comprehensive Guide", DeUcer, New York, NY, 1982. 

K. J. Vooehees, "Analytical Pyrolysis Techniques and Application", Butterworth, London, UK, 1984. 

S.C. Moldoveanu, Analytical Pyrolysis of Natural Organic Polymers, Elsevier, Amsterdam (1998). 

Many of the aforementioned techniques are not appropriate to direct mass-spectrometric analyses of intact high-MW and heat-labile compounds. For such samples, thermal degradation techniques (analytical pyrolysis) can be performed to generate more-volatile compounds of lower molecular weight that are amenable... 

Espitalie, J., Marquis, F., Barsony, J., "Geochemical Logging by the Oil Show Analyzer" Analytical Pyrolysis - Techniques et Applications - Voorhees, Ed. Butterworth, Londres, (1984) ... 

Eudy, L. W. Analytical pyrolysis and derivatization methods combined with gas chromatography-mass spectrometry for the characterization of bacteria and other nonvolatile materials. Univ. South Carolina, Columbia, SC, USA (1983), 197 pp. From Diss. Abstr. Int. B 1984, 45(1), 171. 

Gilbart, J. Fox, A. Morgan, S. L. Carbohydrate profiling of bacteria by gas chromatography-mass spectrometry Chemical derivatization and analytical pyrolysis. Eur. I. Clin. Microbiol. 1987, 6,715-723. 

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... 

Some high molecular weight substances, such as highly polymerized terpenic resins or fossil resins, cannot be directly analysed by GC/MS. In these cases online analytical pyrolysis combined with GC/MS can be used. Pyrolysis-GC/MS applications are described in Chapters 11 and 12. 

Furthermore, the major disadvantages encountered in GC/MS, i.e. undetectability of synthetic polymers and unpredictable interferences due to their presence, may be avoided using the Py-GC/MS technique. All these aspects strongly suggest how useful, and in some cases fundamental, analytical pyrolysis is in the analysis of complex samples, such as those collected from works of art, to implement and support results obtained with wet chemical pretreatment followed by GC/MS analysis. 

J.J. Boon, Analytical pyrolysis mass spectrometry new vistas opened by temperature resolved in source PYMS, Int. J. Mass Spectrom., 118/119, 755 787 (1992). 

G. Chiavari, D. Fabbri, S. Prati, R. Mazeo, D. Bikiaris, S. Daniilia and Y. Chrussoulakis, Analytical pyrolysis application to the characterisation of Byzantine painting layers, Proceedings of 6th International Conference on Non Destructive Testing and Microanalysis for the Diagnostics and Conservation of the Cultural and Environmental Heritage (Eds M. Marabelli and C. Parisi), Euroma, Rome, 1999, pp. 1145 1162. 

D. Scalarone, M. Lazzari and O. Chiantore, Ageing behaviour and analytical pyrolysis char acterisation of diterpenic resins used as art materials Manila copal and sandarac, J. Anal. Appl. Pyrol.,68 69, 115 136(2003). 

D. Fabbri and G. Chiavari, Analytical pyrolysis of carbohydrates in the presence of hexam ethyldisilazane, Anal. Chim. Acta, 449, 271 280 (2001). 

Analytical Pyrolysis Characterization of Fresh and Aged Di- and Triterpenic Resins... 

Huang Y, Eglington G, van der Hage ERE, Boon JJ, Bol R, Ineson P (1998) Dissolved organic matter and its parent organic matter in grass upland soil horizons studied by analytical pyrolysis techniques. Eur J Soil Sci 49 1-15... 

Reprinted from Irwin, Analytical Pyrolysis, Marcel Dekker Inc., NY, 1982). 

Schulten, H.-R. Leinweber, P. Characterization of Humic and Soil Particles by Analytical Pyrolysis and Computer Modeling. J. Anal. Appl. Pyrolysis 1996, 38, 1-53. 

In an attempt to delineate the degree of preservation of lignin in pre-Tertiary coal, we examined numerous coalified wood samples ranging in age from Carboniferous to Cretaceous. The samples were initially screened by solid-state l C nuclear magnetic resonance to detect the possible presence of methoxyl carbon. Once such carbons were detected, the samples were subjected to analytical pyrolysis to determine the relative yields of methoxyphenols which would provide an indication of the state of preservation of the lignin-derived structu units. We report here on the identification of lignin-derived methoxyphenols in the coalified wood samples selected for analytical pyrolysis. 

The analysis of lignitic woods by analytical pyrolysis has shown that lignin structural units can be preserved as biomaikers in samples as old as Carboniferous age, or approximately 300 million years. At least half or more of the pyrolysis products in lignitic wood of Cretaceous age are methoxyphenols characteristic of lignin. The pn uct distributions in these Cretaceous samples indicate that the lignin is mainly altered in the 3-carbon side chains. Phenols, cresols, catechols, and other methylated phenols account for most of the remaining pyrolysis products. It is likely diat these products are also derived frx>m li in, especially lignin that has been altered by coalification reactions. 

Mirau, P. 2004. A Practical Guide to Understanding the NMR of Polymers. Wiley, Hoboken, NJ. Moldoveanu, S. 2005. Analytical Pyrolysis of Synthetic Organic Polymers. Elsevier, New York. Montaudo, G. and Lattimer, R.P. 2001. Mass Spectrometry of Polymers. Taylor Francis, Boca Raton, FL. Oliver, R.W.A. 1998. HPLC of Macromolecules, 2nd ed. Oxford University Press, New York. 

Irwin, W. J. Analytical Pyrolysis A Comprehensive Guide Chromatographic Science Series Vol. 22 Marcel Dekker New York, 1982. 

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