杨木和桉木的二维相关红外光谱

采用红外光谱结合二维相关分析技术，对两种速生阔叶树杨木和桉木进行了快速鉴别研究。结果表明，二者在一维红外光谱图上差别不明显，而二维相关红外谱图具有较大的差别。在800～1 500 cm-1波段范围内，二者的同步二维相关光谱图还比较类似，都在1 221，954，879 cm-1处出现较强的自动峰，在1 470， 1 150，1 1 05， 1 008 cm-1处出现微弱的自动峰。在1 500～1 800 cm-1波段范围内，杨木在1 655 cm-1处有一个非常强的自动峰，在1 600 cm-1附近有一个很弱的自动峰，二者形成了一对正的交叉峰；桉木在1 725，1 650和1 600 cm-1处均出现较强的自动峰，并形成一个较强的3×3峰组。除此之外，桉木还在1 580和1 510 cm-1出现2个弱的自动峰，其中1 580 cm-1和其余4个自动峰形成了较弱的负交叉峰，1 510 cm-1和其他3个自动峰形成正的交叉峰。这说明，桉木在1 500～1 800 cm-1波段对应的官能团比杨木相应的官能团对热微扰更为敏感，杨木和桉木的二维相关红外光谱差别，快速鉴别这两种木材的。

Study on the Eucalyptus and Poplar by Generalized Two-Dimensional Infrared Correlation Spectroscopy

Poplar and Eucalyptus were identified fast by Fourier transform infrared spectroscopy (FTIR) combined with two-dimensional correlation spectroscopy (2D) in the present paper.The two kinds of wood were similar to each other in one-dimensional IR spectra but quite different in 2D FTIR spectra.In the range between 800 and 1 500 cm-1, they are similar and three strong auto-peaks were aroused around 1 221, 954 and 879 cm-1in synchronous spectrum and four weak auto-peaks were aroused around 1 470, 1 150, 1 105 and 1 008 cm-1, respectively.In the range between 1 500 and 1 800 cm-1, one strong auto-peak appeared with Poplar around 1 665 cm-1 and one weak auto-peak appeared around 1 600 cm-1 in synchronous spectrum.They fromed one pair of cross-peaks, whereas three auto-peaks not only at 1 650 cm-1 but also at 1 725 and 1 600 cm-1 appeared with Eucalyptus and they became one 3×3 peak cluster.In addition, Eucalyptus has two weak auto-peaks at 1 580, 1 510 cm-1 and four negative cross-peaks at (1 725 and 1 580 cm-1), (1 650 and 1 580 cm-1), (1 600 and 1 580 cm-1) and (1 510 and 1 580 cm-1) and three positive cross-peaks at (1 725 and 1 510 cm-1), (1 650 and 1 510 cm-1) and (1 600 and 1 510 cm-1), respectively, which suggests that corresponding absorbance bands of Eucalyptus are more susceptive to the thermal perturbation than that of Poplar.The difference of 2D correlation between Eucalyptus and Poplar was obvious.The results proved that 2D correlation spectra could enhance the resolution of infrared spectra and increase the capacity of identification, which make it a powerful, rapid and new approach to identifying Eucalyptus and Poplar.