Chapter 10 Molecular chemistry by pyrolysis–GC/MS of selected samples of the Penido Vello peat deposit, Galicia, NW Spain

Publisher Summary Molecular chemistry reveals significant differences between extracted and non-extractable (residue) peat. In the extracts, lignin and other aromatic fragments, nitrogen-containing moieties are more abundant whereas aliphatics, methyl ketones and lipids are more abundant in the non-extractable fraction. This is not astonishing, since partly oxidized lignin and proteins are hydrophilic and extractable with NaOH, whereas for the extraction of lipids one needs organic solvents. Short-chain straight aliphatics are more abundant in the extractable fraction, and there appears to be a regular decay series of alkanes and alkenes from n -C 28, 28:1 to n -C 10 . One branched alkane that is predominantly present in the extractable fraction is possibly of microbial origin. Some polysaccharide moieties are specifically associated with the extractable fraction and some with the residues. This probably reflects a predominantly microbial origin for the first and predominantly plant-derived for the second, because the plant-derived polysaccharides may still be present in larger molecular units.