Fig. 8

Partial py-GC-FID chromatograms from modern pine (top) and archaeological wood from a heavily decayed coffin (bottom). Points of interest include: a decrease in the relative intensity of cellulose related peaks at the start of the chromatogram and a decrease in the relative intensity of levoglucosan (a cellulose pyrolysis product) in the degraded sample indicating loss of cellulose; an increased intensity of short chain degradation products (e.g. phenol, 2-methyl phenol and 3-methyl phenol) and an increased intensity of oxidised compounds (*) later in the chromatograms in the degraded sample, signifying lignin modification