Polysaccharide analysis pyrolysis

FI mass spectra were proven informative in algal polysaccharide analysis [2]. Characteristic Py-Fi mass spectra were reported for agarose, aiginic acid, laminaran, etc. Also, Py-GC/MS studies were done on algal polysaccharides [64a,64b]. The identification of pyrolysis products for several polysaccharides from red algae showed, as expected, compounds commonly obtained during polysaccharide pyrolysis. A list of several compounds found in these pyrolysates is shown in Table 7.8.2. 

Combination of pyrolysis and m.s. has been found to enable rapid analysis of sialic acids and other carbohydrates (for ng quantities of oligosaccharides and polysaccharides). Thus, the presence of (2— 8) and (2—>9) linkages in Neisseria meningitidis capsular polysaccharides has been confirmed.154... 

A few pyrolysis studies done on yeasts and yeast-like fungi did not attempt to analyze individual polysaccharides but to obtain a fingerprint characterization [67], It was also common to use statistical techniques such as factor analysis for the data interpretation. It was not unusual to find N-acetylamino sugar units in fungal polysaccharides. These units showed characteristic peaks in Py-MS that allowed the distinction of different materials. 

The main pyrolysis mechanism of nucleic acids (occurring at temperatures as low as 180°C) is the expulsion of the polysaccharide moiety with the simultaneous formation of base-phosphate condensates. The base phosphate complex is further pyrolysed, yielding the base fragments. Compared with polysaccharides and lignin, the application of Py-GC/MS techniques to the analysis of nucleic acids is still in its infancy. 

In this chapter we wiU critically review mainly those publications that deal directly with the application of analytical pyrolysis to the examination of art or archaeological objects. It should be indicated nevertheless that a substantial literature devoted to analysis of such materials as wood, polysaccharides, textiles, proteins, and numerous synthetic polymers can be found in other chapters of this book. 

Measurements of IR absorption of thin films are useful for identification with authentic samples, particularly if in addition pyrolysis and GC/IR analysis of the decomposition products is carried out. The use of specific enzymes is important in aiding the isolation of polysaccharide components from natural sources, and in producing identifiable oligosaccharides that facilitate molecular structural analysis. 

A technique for the controlled thermal degradation of polysaccharides by Curie-point pyrolysis with analysis of the pyrolysis products by field ionization m.s. has been developed. Integrated ion recording by photographic detection gives reproducible fingerprints in a method which appears to be a useful tool for the characterization and identification of microgram quantities of polysaccharides. 

General use of analytical pyrolysis is given in Table 2.23. The earliest application of analytical pyrolysis was the identification of the isoprene unit in rubber in 1860 [565]. Analytical pyrolysis is now extensively applied for the analysis of natural and synthetic polymers, textile fibres, wood products, foods, leather, paints, varnishes, adhesives, paper, biopolymers (proteins, polysaccharides), etc., and allows the study of a broad variety of materials including carpets, clothing, electronic components, upholstery, plastic recyclates, fuel sources, oil paintings, etc. 

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