Investigation of thermally treated beech (Fagus sylvatica) and spruce (Picea abies) by means of multifunctional analytical pyrolysis-GC/MS

Multifunctional analytical pyrolysis – GC/MS comprising evolved gas analysis (EGA), heart-cut analysis (HCA), and conventional pyrolysis (single-shot analysis; SSA) has been demonstrated to be a powerful analytical approach to study chemical alterations taking place in wood during thermal treatment (curing) as it is increasingly used on a large scale to improve certain properties such as decay resistance or dimensional stability. Following this approach it has been demonstrated that thermal treatment of beech (Fagus sylvatica) and spruce (Picea abies) at 220 °C effects structural alterations of both thermally labile carbohydrates and certain lignin moieties. Furthermore, it has been shown that minor differences between the peak pattern as obtained by comparative heart-cut and single-shot analysis were caused by methodological differences in terms of pyrolysis conditions.

► Thermally modified timber (TMT) was investigated by combined methods of multifunctional pyrolysis-GC/MS for the first time.
► Besides conventional Py-GC/MS technique, the extended methods of evolved gas analysis (EGA) and heart-cut analysis (HCA) were performed.
► The thermal behaviour and alteration of the main wood components were examined.
► Degradation of thermally labile carbohydrates and specific lignin moieties were detected.