In an attempt to develop a method by which the chemical components of whole wood samples could be separated on a quantitative basis, the reactions of gaseous dinitrogen pentoxide with model substances and with acetone-extracted wood have been studied. The crystalline compounds D-mannitol, benzoic acid and D,L-tartaric acid were smoothly nitrated by exposure to an excess of the pentoxide at 0 ± 2° C. and the crystalline products D-mannitol hexanitrate, D,L-tartaric acid dinitrate and m-nitrobenzoic acid were recovered directly in quantitative yield. Good yields of the crystalline although somewhat less pure nitrates of D,L-mandelic acid, β-methyl-D-glucopyranoside and D-sorbitol were obtained in similar nitrations. D-Mannose, D-fructose, dulcitol, sucrose, maltose, lactose, cellobiose, vanillic acid, salicylic acid and vanillin gave poor yields of syrupy nitrated products. A beechwood xylan and holocellulose and lignin of western red cedar, isolated by conventional technics, were nitrated by the gaseous pentoxide method in yields and nitrogen contents comparable to those reported for other nitration methods. The xylan and holocellulose nitrates were incompletely soluble in acetone and the solubility of the nitrated lignin varied with the time of nitration. Optimum conditions were established for the nitration of acetone-extracted western red cedar heartwood. The weight ratio of nitrated wood : wood was closely reproducible and exceeded previously reported values; total nitrogen and ester nitrogen contents of the nitrated wood were reproducible within, the experimental error of the determinations. The nitration reaction was not entirely quantitative since an average of 2.3% methoxyl was lost from the wood and the weight increase calculated from the total nitrogen content was, on the average, 3% lower than the observed value. Successive extraction with anhydrous acetone and methanol applied alternately, dissolved up to thirty-five percent of the nitro-wood and indicated that the nitration-solvent extraction technic should have value as a tool in the study of wood chemistry. / Science, Faculty of / Chemistry, Department of / Graduate

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The aims of this study were to characterise and quantify wood extractives in E. grandis and E. nitens and determine the impact of wood extractives on pitch formation. Initially a comparison was made with individual solvent abilities to determine whether the polarity index plays a role in the amount of extracts being removed. After this different methods were used to determine the extractive amounts. These methods included hot water/ethanol-toluene, hot water/acetone and followed by acetone only. Analyses such as UV-Vis, acidolysis and HPLC were carried out to determine the presence of lignin and sugars in the extracts and sawdust respectively. Lastly GC and GC-MS was performed to characterise and quantify extractives present in the extracts from the different methods. The results showed that acetone is the preferred solvent as it removes higher amounts of extractives than ethanol-toluene. There is also a higher amount of extractives in E.grandis sawdust than in the E. nitens sawdust and pitch sample. There seems to be more fatty acids and sterols in the E. nitens sawdust sample extracted the using acetone (no hot water extraction) method while hydrocarbons are extracted more in E. grandis using the same method. It was found after GC-MS analysis that fatty acids tetradecanoic acid methyl ester and hexadecanoic acid methyl ester and hydrocarbon 1-Octadecene were common to both species. The common compounds in the pitch and sawdust of E. nitens are heptadecanoic, octadecanoic, tetradecanoic and tridecanoic acid methyl esters, gamma and beta sitosterol and Stigmasterol, 1-docosene and lastly 1-nonadecene hence these compounds are more likely to cause pitch. After analysis using UV analysis and acidolysis there was indication that there were lignin breakdown products present in the wood extracts, in minimal amounts. HPLC indicated no sugars present in the extracts. It is concluded that GC and GC-MS are the recommended analytical tools in characterising and quantifying wood extractives in E. grandis and E. nitens. All extractives in both species were quantified and identified using GC and GC-MS respectively. / Thesis (M.Sc.)-University of KwaZulu-Natal, Westville, 2011.

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