卢氏黑黄檀和染料紫檀木材特征与檀香紫檀相似, 特别是两者经过加色精的木蜡油涂饰后, 用肉眼很难与珍贵的檀香紫檀分辨。 市场上销售的很多红木家具为了达到防腐、 防尘、 防开裂的性能以及提高红木表面光泽度和显现珍贵木材的纹理, 大都进行了木蜡油表面涂饰加工, 因而只研究木材本身的鉴别不能满足市场需求。 借助红外光谱(FTIR)结合二阶导数红外光谱(SDIR)和二维相关红外光谱(2D-IR)技术, 对经过木蜡油涂饰的檀香紫檀(Pterocarpus santalinus)、 染料紫檀(P.tinctoricus Welw)和卢氏黑黄檀(Dalbergia louuelii)进行了红外光谱分析。 通过打磨—涂底油—打磨—涂面油—干燥的涂饰工艺对3个树种进行表面涂饰。 分别取3个树种素材的木粉和经过表面涂饰的木材表面的木粉进行FTIR, SDIR和2D-IR三级鉴别分析, 同时测定了木蜡油的FTIR谱图。 结果表明: (1)木蜡油FTIR谱图在2 925, 1 733, 1 465和1 378 cm-1较强的特征峰出峰位置与3个树种木材本身的出峰位置基本重合, 且在2 854 cm-1处归属于亚甲基C—H对称伸缩振动, 1 233 cm-1处归属于羧基C—O伸缩振动, 729 cm-1处归属于长链的亚甲基C—H弯曲振动的特征峰在涂饰后三种样品的FTIR谱图中有相同的体现, 说明木蜡油涂饰未对3个树种红外谱图的特征峰产生影响; 3个树种表面涂饰前后FTIR谱图的相关系数同时可以对木蜡油涂饰未对3个树种的特征峰产生影响进行佐证; (2)FTIR谱图在1 595, 1 060和836 cm-1处可以将染料紫檀与檀香紫檀和卢氏黑黄檀两个树种区分开; SDIR谱图可以在1 551 cm-1将卢氏黑黄檀区分开, 并能进一步对染料紫檀的特征峰进行验证; 在2D-IR光谱中, 在1 425~1 800和850~1 300 cm-1两个波段范围, 檀香紫檀的自动锋明显区别于其他两个树种, 在1 250 cm-1处归属于醚类化合物的吸收峰可以将檀香紫檀区分开。 目前红木识别主要利用木材解剖方法, 表面涂饰大多集中在木材材色变化研究。 借助红外光谱技术, 最终利用各个树种和木蜡油在红外光谱谱图中不同的特征峰体现的官能团差异直接推测特征成分的含量差异, 无须测定其特征成分的具体物质, 进而实现准确、 快速地把经木蜡油表面涂饰的檀香紫檀及与其易混淆的染料紫檀和卢氏黑黄檀区分鉴别。

The wood characteristics of P. tinctoricus Welw and Dalbergia louuelii are similar to Pterocarpus santalinu. Especially, after the two species have been painted with colored wood wax oil, it is difficult to distinguish from P. tinctoricus Welw, Dalbergia louuelii and Pterocarpus santalinu. As many rosewood furniture sold on the market are mostly surface-finished in order to achieve anti-corrosion, dust-proof, anti-cracking properties, as well as to improve the surface gloss and the texture of precious wood, the identification of wood itself is far from meeting market demand. Pterocarpus santalinus, P. tinctoricus Welw and Dalbergia louuelii finished with Wood wax oil were analyzed by the Tri-step Infrared identification(FTIR, SDIR and 2D-IR). The three species were surface finished by Polishing-Carrier oil-Polishing-Coating oil-Drying. The wood powder of three species themselves and three surface-coated samples were analyzed by means of three IR spectroscopic methods, and the FTIR spectrum of wood wax oil was also determined. The results show that: (1) The FTIR spectrum of wood wax oil has strong peak at 2 925, 1 733, 1 465 and 1378 cm-1, which coincide with the peak positions of three species themselves. C—H methylene symmetric stretching around 2 854 cm-1, C—O stretching of aliphatic aldehydes at 1 233 cm-1 and long-chain C—H methylene bending at 729 cm-1 have the same embodiment between wood wax oil and three surface-coated species. The above results indicate that the characteristic peaks of infrared spectra of three species are not affected by wood wax oil. Correlation coefficient between three species themselves and three surface-coated samples can also confirm it. (2) The FTIR spectrum can distinguish P. tinctoricus Welw from Pterocarpus santalinus and Dalbergia louuelii at 1 595, 1 060 and 836 cm-1; The SDIR spectrum can distinguish Dalbergia louuelii from 1 551 cm-1 and can further verify the characteristic peak of P. tinctoricus Welw; For the 2D-IR spectrum, in the range of 1 425~1 800 and 850~1 300 cm-1, the automatic front of Pterocarpus santalinus is obviously different from the other two species, and the absorption peak attributed to the ether compound at 1 250 cm-1 can separate Pterocarpus santalinus. Redwood identification mainly uses wood anatomy and Surface finishing is mostly concentrated on the study of wood color change. This article makes the best of infrared spectroscopy. Finally, Functional group differences with characteristic peaks of tree species and wood wax oil can directly speculate different content of characteristic components and the specific substances of characteristic components are not required to determine. It is possible to accurately and quickly distinguish the Pterocarpus santalinus painted with wood wax oil and P. tinctoricus Welw and Dalbergia louuelii with which people are confused.