The Svennerholm modification of the Elson-Morgan method for glucosamine analysis was evaluated for its applicability to the rapid determination of chitin in wood decay fungi. The evaluation included extent of chromogen interference, sensitivity, color stability, and hydrolysis conditions for maximum release of glucosamine from fungal cell walls. With our further modification, the Svennerholm method was shown to be suitable for rapid quantitative determination of fungal chitin without chromatographic separation of hydrolysate chromogens.

ABSTRACT:The objective of this research was to improve the fire-retardant properties of wood in one treatment using a phosphorus pentoxide-amine system. Phosphorus pentoxide and 16 amines including alkyl, halophenyl, and phenyl amines were compounded in N,N-dimethylformamide and the resulting solutions containing phosphoramides were reacted with wood. The characteristics of phosphoramidereacted wood were analyzed by FTIR, energy-dispersive X-ray analysis, and elemental analysis. Fire retardancy of phosphoramide-reacted woods was evaluated by DSC and thermogravimetric analysis (TGA). DSC demonstrated that the modification can lower the onset of an endotherm and decrease the heat of combustion and heat flow. TGA showed that most of the phosphoramide-reacted woods had higher char yields than that of wood impregnated with diammonium phosphate.

Pine sapwood reacted with methyl or phenyl isothiocyanate to form bonded methyl or phenyl thiocarbamate in situ resisted attack by the brown-rot fungus Gloeophyllum trabeum. Wood reacted with methyl isothiocyanate to 7.2 percent chemical weight gain (99 mmol/100 g wood) and phenyl isothiocyanate to 6.8 percent chemical weight gain (50 mmol/100 g wood) had 0.2 percent and 2.9 pcrcent weight loss, respectively, in a Standard 12-weck soil-block decay lest. Methyl-isothiocyanate-modified wood lost 12 percent of the methyl thiocarbamoyl group whereas phenyl-isothiocyanate-modified wood lost 8 percent of the phenyl thiocarbamoyl group. The greater hydrophobicity of the phenyl group compared to the methyl group may contribute to the stability of the phenyl thiocarbamoyl group in modified wood.

Resistance of wood reacted in situ with phosphorus pentoxide-amine to the brown-rot fungus Gloeophyllum trabeum and white-rot fungus Trametes versicolor was examined. Wood reacted with either octyl, tribromo, or nitro derivatives were more resistant to both fungi. Threshold retention values of phosphoramide-reacted wood to white-rot fungus T. versicolor ranged from 2.9 to 13.3 mmol, while these for brown-rot fungus G. trabeum ranged from 8.1 to 19.2 mmol. Wood reacted with phosphoramide tested to be more resistant to white-rot than brown-rot attack.

No abstract