便携式近红外光谱仪用于东阿阿胶鉴定及特征波长筛选研究

Identification of Dong’e Ejiao and its characteristic wavelength selecting using portable NIR spectrometers

目的采用便携式近红外(near infrared,NIR)光谱仪建立东阿阿胶鉴别分析模型,并优选出特征波段。方法采用BWS903型NIR光谱仪和microPHAZIR^(TM)RX型NIR光谱仪2款便携式光谱仪采集了47份阿胶样品的光谱,并采用软独立建模聚类分析(soft independent modeling class analog,SIMCA)和偏最小二乘判别分析(partial least squares discriminant analysis,PLS-DA)等化学计量学算法,建立了东阿阿胶的判别分析模型。结果所建立模型能够准确区分东阿阿胶和其他品牌阿胶。在此基础上,采用相关系数法优选出BWS903光谱特征波长为1300~1380 nm和1460~1540 nm;microPHAZIR^(TM)RX光谱特征波长为1600~1680 nm和2160~2240 nm,上述波段分别代表-NH_(2)和-CONHR肽键的1级倍频吸收,这些波段可作为东阿阿胶的特征波段,并可据此设计专用型、小型化的NIR光谱仪,用于东阿阿胶的品牌鉴定。结论便携式NIR光谱携带方便,分析快速,借助化学计量学算法即可进行品牌鉴别,在名贵中药材的鉴定方面具有较好的推广应用前景。

Objective The identification models of Dong'e Ejiao hide gelatin were established by portable near infrared(NIR)spectrometers,and the characteristic bands of NIR were selected.Methods In this research,two portable near-infrared spectrometers,named B&W Tek BWS 903 NIR spectrometer and microPHAZIR™,are used for collecting the spectra of donkey hide gelatin,and combined with chemometric algorithms,such as soft independent modeling of class analogy(SIMCA)and partial least squares discriminant analysis(PLS-DA),the discriminant analysis models of Dong'e gelatin were established.Results The established discriminant analysis models can distinguish Dong'e gelatin from other brands of donkey hide gelatin accurately.The characteristic wavebands of BWS 903 spectra,1300—1380 nm and 1460—1540 nm,and the characteristic wavebands of microPHAZIR^(TM)spectra,1600~1680 nm and 2160—2240 nm,were selected using correlation coefficients method,which represent the first-order double-frequency absorption of-NH_(2) and-CONHR,respectively.These bands can be regarded as the characteristic bands of Dong'e donkey hide gelatin,and a special and miniaturized near-infrared spectrometer can be designed to establish the brand protection system of Dong'e donkey hide gelatin.Conclusion Portable near infrared spectrometer is characterized by easy to carry and fast to analyze.Brand identification of Dong'e donkey hide gelatin can be realized with the help of basic chemometrics algorithms.The established methods have a good prospect of popularization and application in the identification of precious traditional Chinese medicine.