杉木综纤维素和木质素的近红外光谱法测定

用近红外光谱法对杉木中综纤维素和木质素含量进行了快速测定.用常规湿化学方法测定了48个杉木木材样品的综纤维素和木质素,用近红外光谱仪采集相应的光谱,进行二阶微分处理和平滑预处理后,用偏最小二乘法和完全交互验证方式建立相应预测模型.综纤维素校正模型和预测模型的相关系数分别为0.96和0.93;预测标准误差分别为0.39和0.50;木质素校正模型和预测模型的相关系数分别为0.99和0.90;预测标准误差分别为0.10和0.28.结果表明,近红外光谱法可以快速分析木材中综纤维素和木质素含量.

Determination of Holocellulose and Lignin Content in Chinese Fir by Near Infrared Spectroscopy

The contents of holocellulose and lignin of wood are important determinants of the pulping quality of wood.The determination of holocellulose and lignin contents using traditional chemical methods is a costly and time-consuming process.Near infrared reflectance(NIR) analysis offers a fast,nondestructive testing and low cost alternative for prediction of wood quality.In the present article,the total amounts of holocellulose and lignin contents of 48 samples were analyzed according to standard wet-chemical method.All samples were milled using a Standard Wiley knife mill with a 2 mm screen.The 2 mm material was sieved with a 40-60 mesh sieve.Then,near infrared(NIR) spectra were collected in diffuse reflectance from samples of meal contained in a spinning cup by an analytical spectral devices(ASD) Lab Spec at wavelengths between 350 nm and 2 500 nm.The raw spectra were pretreated by the second derivative and smoothing,then the NIR model was built using partial least-squares statistical analysis and full cross validation.The coefficients of correlation(r) of calibration and validation for holocellulose were 0.96 and 0.93,respectively;the standard error of calibration(SEC) and the standard error of prediction(SEP) were 0.39 and 0.50,respectively.For lignin,the values for r of calibration and validation were 0.99 and 0.90,while the SEC and SEP were 0.10 and 0.28,respectively.It was concluded that NIR analysis is a reliable,fast and nondestructive testing predictor of holocellulose and lignin content of wood in Chinese fir.