硫磺熏蒸的葛根横纵截面快速判别分析

采用近红外光谱分析技术,对不同硫磺熏蒸的葛根进行鉴别研究.将葛根饮片及其硫熏饮片进行横截面与纵截面原始光谱的采集,并对原始光谱进行主成分分析(PCA),采用随机法划分样本集,进而比较不同预处理方法,通过对样品不同截面光谱建立判别模型,计算每个模型外部验证的识别率.采用正交性检验和非参数检验对数据进行正态性检验.结果表明不同截面由于结构不同所以吸光度不同,并且对原始光谱进行主成分分析,发现当主成分数为3时累计贡献率达到99.2％,MSC+ 1D+ Savitzky-Golay预处理方法所建模型最好,判别模型中横截面的50个模型,其识别率为(94.4±0.66)％,纵截面的识别率为(95.6±0.75)％,总截面为(95.3±0.65)％.3组识别率的差异并不大.对各组模型的预测性能进行差异性分析,认为横截面、纵截面及总截面建模结果没有明显差异,说明近红外光谱分析技术可以应用于中药材硫熏与否的快速鉴别.

Rapid discriminant analysis of sulfur fumigated Puerariae Lobatae Radix based on vertical and horizontal surfaces

Near-infrared (NIR) was used as rapid analysis method to identify the sulfur fumigated Puerariae Lobatae Radix. NIR spectra of the cross-sectional and longitudinal selection of samples were acquired. Principal component analysis was conducted. The samples were randomly selected. The different pretreatment methods were compared. Discriminant models were established for every type of spectra to calculate the recognition rate. The orthogonal test and nonparametric test were used to test data normality. The result showed that absorbance values of different sections were different due to the different structure, and the raw spectra were analyzed by PCA method. The result founded that the cumulative contribution rate was arrived at 99.2% while the PC numbers were arrived at 3. The pretreatment method based on the MSC+1D+Savitzky-Golay was the best to establish the model. For the 50 models constructed with cross-section and longitudinal spectra and total spectra, the recognition rate were (94.4±0.66)%, (94.4±0.66)%, (95.3±0.65)%, respectively, and no difference was observed. The NIR method could be used to identify the sulfur fumigated Puerariae Lobatae Radix.