Tomographic analysis of siliceous particulates in Australian turpentine wood (Syncarpia glomulifera) through X-ray micro-computed tomography.

X-ray micro-computed tomography (XμCT) allows a non-destructive and three-dimensional (3D) study of otherwise complex and opaque wood tissues. In wood research, XμCT datasets are highly useful for the qualitative and quantitative examination of wood structures. In this study, XμCT was introduced and tested for examining X-ray dense silica particles in the Australian turpentine wood (Syncarpia glomulifera). It was possible to three-dimensionally visualize and numerically quantify silica particles. Numerical analysis was performed to scrutinize the size and content of silica particles. In comparative studies of silica size through scanning electron microscopy and silica content through thermo-gravimetric analysis after acid digestion of ash, our findings pointed out that XμCT is indeed a powerful tool for examining silica particles in wood; because XμCT enables a simultaneous visualization and quantification of the silica particles in 3D without being destructive. Despite these benefits, comparative examination through scanning electron microscopy and energy-dispersive X-ray spectroscopy is necessary to verify silica particles in tomographic images. XμCT technology might further aid in probing the biological and ecological function of silica in silica-bearing wood species.