Quantification of methylene bis thiocyanate in wood and its effect on a sapstain fungus Ophiostoma floccosum
The mobility and concentrations of MBT at different depths of wood billets (200 mm long, 40 mm in diameter) were determined using NMR spectroscopy and ICP-ASE, and then correlated the effect of wood MBT concentrations on growth of O. floccosum in a bioassay using stereomicroscopy and confocal laser scanning microscopy (CLSM).
The 13C NMR spectra showed the presence or absence of MBT in wood but was unable to detect small concentrations. ICP-ASE however, produced quantitative data across the depth (40 mm) of the wood billets tested. Within 7 days of storage, MBT penetrated from surface to pith but showed significantly higher concentrations of MBT in surface wood compared to pith wood.
Present study highlighted the benefit of using CLSM for fungal detection in wood. The information obtained from the ICP-ASE and the CLSM analysis suggested that to inhibit growth of O. floccosum, the MBT concentration needs to be greater than 55 ?g/g of dry wood. Due to its high detection capacity, ICP-ASE is identified as an excellent tool for MBT detection and quantification in wood.