Study On Chemical Properties Of Six Rosewoods In Dalbergia Genus And Pterocarpus Genus

Chemical property is an important aspect of wood properties, which affects the physical and mechanical properties, natural durability, color, processing and utilization of wood. Chemical composition of six kinds rosewoods such as Dalbergia cochinensis, Dalbergia cambodiana, Dalbergia oliveri and Dalbergia granadillo in Dalbergia genus along with Pterocarpus macrocarpus and Pterocarpus santalinus in Pterocarpus genus were studied in this paper. Organic composition, ash and metal content of these six rosewoods were determined. Then chemical composition of methanol extractives, alcohol-benzene extractives and acetic ether extractives of these six rosewoods was ascertained by GC-MS analysis. Cluster analysis, correlation coefficient analysis and comparative analysis of the characteristics of components were held as well. The conclusions can provide theoretical basis for utilization and identification of rosewoods. By above, the conclusions were as follows:1. Chemical composition of Dalbergia cochinensis wood were similar to Dalbergia Cambodian wood except for ash content, which ash content of Dalbergia cambodian wood was higer than that of Dalbergia cochinensis wood. There were differences between different wood species belong to the same genus in chemical composition. In Dalbergia genus, Dalbergia granadillo wood had the biggest cellulose content (45.85%). And in Pterocarpus genus, Pterocarpus santalinus had the biggest extractive content. Six rosewoods in Pterocarpus Genus and Dalbergia Genus wood showed slant acidity, but there were different acid-base properties between these six rosewoods, which PH value of Dalbergia cochinensis wood was smallest while that of Dalbergia oliveri wood was biggest.2. Metal element species and their contents of six different rosewood was different, except that six rosewoods in Pterocarpus Genus and Dalbergia Genus contained rich Ca element. Cu element and Mn element were not detected in Pterocarpus santalinus and Cu element was not detected in Dalbergia cochinensis. Metal contents of Dalbergia cochinensis wood and Dalbergia cambodiana wood varied greatly except Na element. So the author considered that Dalbergia cochinensis wood and Dalbergia cambodiana wood could be distinguished according to metal elements.3. GC-MS analysis of six solvent extractives such as benzene-ethanol extractive, hot water extractive, acetone extractive, chloroform extractive, acetic ether extractive and methanol extractive from six rosewoods in Dalbergia Genus and Pterocarpus Genus was carried out,the results showed that the benzene-ethanol extractives, methanol extractives and acetic ether extractives could reveal the chemical composition of the extractives from these six rosewood comprehensively. Specific results were as follows:21kinds of compounds with over1%content which mostly were Esters and ketones were identified in Dalbergia cochinensis wood, among which,9kinds of compounds were identified in benzene-ethanol extractive,10kinds of compounds were identified in methanol extractive and9kinds of compounds were identified in acetic ether extractive.25kinds of compounds with over1%content which mostly were Esters, ketones and alcohol compounds were identified in Dalbergia cambodiana wood, among which,8kinds of compounds were identified in benzene-ethanol extractive,13kinds of compounds were identified in methanol extractive and11kinds of compounds were identified in acetic ether extractive.46kinds of compounds with over1%content which mostly were ketones and alcohol compounds were identified in Dalbergia oliveri wood, among which,14kinds of compounds were identified in benzene-ethanol extractive,19kinds of compounds were identified in methanol extractive and26kinds of compounds were identified in acetic ether extractive.22kinds of compounds with over1%content which mostly was ketones compounds were identified in Dalbergia granadillo wood, among which,10kinds of compounds were identified in benzene-ethanol extractive,9kinds of compounds were identified in methanol extractive and11kinds of compounds were identified in acetic ether extractive.26kinds of compounds with over1%content which mostly was ethanol compounds were identified in Pterocarpus macrocarpus wood, among which,15kinds were identified in benzene-ethanol extractive,11kinds of compounds were identified in methanol extractives and15kinds of compounds were identified in acetic ether extractives.42kinds of compounds with over1%content which mostly were Enol and anthracene compounds were identified in Pterocarpus santalinus wood, among which,19kinds of compounds were identified in benzene-ethanol extractive,18kinds of compounds were identified in methanol extractive and13kinds of compounds were identified in acetic ether extractive.The common chemical composition of these six rosewoods in Dalbergia Genus and Pterocarpus Genus was alkene compounds mainly.4. Cluster analysis of extractives chemical composition for six rosewood in Pterocarpus Genus and Dalbergia Genus was carried out,the results showed that Pterocarpus macrocarpus and Pterocarpus santalins belong to the same genre while the rest four kinds belong to the same genre. Relation coefficients of methanol extraction liquid components between different batches were all over0.6for six rosewoods in Pterocarpus Genus and Dalbergia Genus, furthermore, those were all over0.9for Dalbergia cochinensis, Dalbergia cambodiana, Dalbergia granadillo, Pterocarpus macrocarpus woodChemical composition and content of methanol extraction liquid from the same rosewood was relaticely stable. On the other hand, there were difference in methanol extraction GC-MS total ion figure between Dalbergia Genus and Pterocarpus Genus. The correlation coefficient of methanol extraction GC-MS total ion figure between different kinds wood in Dalbergia Genus and Pterocarpus Genus were almost less than0.35. Therefore, wood species can be distinguished based on the correlation coefficient of methanol extraction GC-MS total ion figure. Six rosewoods in Pterocarpus Genus and Dalbergia Genus had their unique one or more chemical compositions as well as a set of characteristic peak themselves. If a certain rosewood which need to be determined contained these special chemical compositions, it can be identified as known corresponding wood species. These data suggested that rosewood can be distinguished by chemical means.