Abstract

The distribution of lignin, carbohydrates, and metal ions on the surface of spruce and aspen wood tissue sections was investigated by time-of-flight secondary ion mass spectrometry (ToF-SIMS). The distribution patterns of metals and lignin in ray cells, vessels, and fibres were different, whereas carbohydrates were uniformly distributed across the sections of all morphological regions. In spruce sapwood, Ca, Mg, Na, K, Fe locations was more pronounced in the bordered pit tori and inner layer of ray parenchyma cells. Little lignin was detected in these regions. In spruce heartwood, the degree of lignification was low on the surfaces of bordered pit tori; however, Na and K were not detected here. In compression wood from spruce, the locations of p-hydroxyphenyl and guaiacyl units was different in cell wall layers. In aspen sapwood, the main locations of Ca, Mg, Na, K were in lumina of longitudinal parenchyma cells and in pits between vessels and ray cells. Low-intensity signals of the secondary ions assigned to lignin were found in the same morphological regions.