Curie-point pyrolysis-capillary gas chromatography-high-resolution mass spectrometry of microcrystalline cellulose

Microcrystalline cellulose was analysed by Curie-point pyrolysis-capillary gas chromatography-mass spectrometry (Py-GC-MS) under electron impact (70 eV) as well as chemical ionisation (isobutane) conditions. Almost all interpretations could be supported by high-resolution mass spectrometric data, obtained by Py-GC-high-resolution MS. The pyrolysis products identified can be classified into several main groups i.e. carbonyl compounds, acids and methyl esters, furans, pyrans, anhydrosugars and hydrocarbons. Altogether 96 compounds have been found, and structural assignments could be given to 94 of them. From these compounds 25 have not been identified earlier in pyrolysates of polysaccharides. Levoglucosan is the major GC amenable pyrolysis product detected. Several formation pathways are proposed to account for the formation of a number of pyrolysis products from levoglucosan and/or cellobiosan. An overview showing the thermal degradation pattern of cellulose through anhydrosaccharides to smaller pyrolysis products is also presented.