基于太赫兹时域光谱的3种中药材真伪鉴别

Identification of three Chinese herbal medicines based on terahertz time-domain spectroscopy

基于太赫兹时域光谱对3组物理形态区分度很小的中药材进行光谱检测,并结合主成分分析(PCA)与K均值聚类算法(K-means)对光谱数据进行差异性对比.研究结果表明所测真伪品中药的时域信号相对于参考信号有了明显的延迟,真伪品的频域吸收谱差别明显,3组中药的吸收系数及折射率在0.2〜1.5 THz内存在明显差异.对得到的吸收光谱数据进行降维处理,并应用K均值聚类算法得到主成分得分图,3组真伪中药的差别判断率高达100%.太赫兹时域光谱结合主成分分析在中药真伪的鉴别中具有很好的应用前景,可以直观地得到真伪中草药的差别,具有快速、稳定、准确、无损的优点,对未来相关便携式太赫兹中药品质检测仪器的开发也具有很高的研究价值.

This paper employs terahertz(THz)time-domain spectroscopy combined with principal component analysis(PCA)and K-means clustering algorithm for the detection of three groups of Chinese herbal medicines with little discrimination in physical form.The results show that the THz time-domain spectrum of the authentic Chinese herbal medicines has a significant delay relative to the reference signal,and the absorption spectrum of three groups of Chinese herbal medicines shows distinct absorption coefficients and refractive index in the range of 0.2-1.5 THz.The obtained spectral absorbance data is subjected to dimensionality reduction processing and is applied to the K-means clustering algorithm.The score map of three sets of authentic Chinese herbal medicines obtained by PCA reaches up to 100%.The method of terahertz time-domain spectroscopy combined with PCA has a good application prospect in the identification of Chinese herbal medicine authenticity with the advantages of being fast,stable,accurate and non-destructive.It also has high research value for the development of related portable terahertz instruments for Chinese herbal medicines quality testing.