Application Of Near Infrared Spectroscopy In The Identification Of Dioscoreae Nipponicae Rhizoma

Dioscoreae Nipponicae Rhizoma is a herbal medicine with anti-inflammatory,expectorant,wind-dispelling,relaxing muscles and collaterals,promoting blood circulation,relieving pain,relieving cough and asthma.The appearance of Dioscoreae Nipponicae Rhizoma is similar to that of Dichroae Radix,Celastrus Orbiculatus Thunb,Dioscoreae Rhizoma and Dioscoreae Panthaicae Rhizoma.The existing identification methods of Dioscoreae Nipponicae Rhizoma include trait identification,microscopic identification,thin layer chromatography(TLC)and high performance liquid chromatography(HPLC),etc.These methods have disadvantages such as low accuracy,cumbersome operation,long test period,large reagent consumption,and difficult to learn and master.Therefore,a more rapid,simple,accurate and efficient identification method is needed.Near infrared spectrum technology is the combination of nearly infrared spectrum measurement technology,chemometrics technology,computer technology and modern analysis technology.The technology can measure both the diverse chemical composition and the physical parameters at the same time,and has the advantages of quick,accurate,simple and convenient,green and environmental protection.It is mainly used for instantly analysis of complex samples,andhas been used for the identification of Chinese traditional medicine(TCM)analysis.In this study,a fast and accurate method for the identification of Dioscoreae Nipponicae Rhizoma and its confused products was established by using nirs qualitative identification method.The main research results are as follows:1.We collected 302 Dioscoreae Nipponicae Rhizoma samples from 17 provinces in China and 71 samples of Dichroae Radix,Celastrus Orbiculatus Thunb,Dioscoreae Rhizoma and Dioscoreae Panthaicae Rhizoma,and measured their near-infrared spectra.2.TQ Analyst software was used to conduct smoothing,Savitzky-Golay derivative and Norris derivative on the sample spectra;Using Similarity matching(SM)algorithm,Distance matching(DM)algorithm,Discriminant analysis(DA)algorithm and Quality Control(QC)Comparison retrieval algorithm,more than 20 analysis model were established,the analysis results of the models were checked,and the best identification models was selected.3.Through a large number of model calculations,the influence of different modeling algorithms and different modeling parameters on the model analysis effect was compared,and the following results were obtained.(1)The best model is the DA method model(7 points smoothing processing on the spectrum),which has a 100% identification rate for Dioscoreae Nipponicae Rhizoma and all kinds of confused products,can accurately identify the sample as Dioscoreae Nipponicae Rhizoma,Dichroae Radix,Celastrus Orbiculatus Thunb.Using the savitzky-golay derivative and Norris derivative processing model,the five kinds of TCM can also be distinguished,but with less reliability.(2)The DM method analysis model and QC Comparison retrieval analysis model,can only distinguish whether the sample is Dioscoreae Nipponicae Rhizoma or not,and can not distinguish the kind of confused products.(3)SM model can not be used as the identification method of Dioscoreae Nipponicae Rhizoma and confused products.(4)Both smooth processing and Norris derivative processing can improve the resolution effect,savitzky-golay derivative processing to improve the resolution is not helpful.(5)For natural products,because their spectrograms are very similar,the modeling effect of DM and DA is better,while the modeling effect of SM and QC Comparison retrieval analysis is worse.The innovations of this study are as follows:In this study,a rapid and accurate near-infrared spectroscopy method for the identification of Dioscoreae Nipponicae Rhizoma and four confused products was established,which filled in the blank of near-infrared spectroscopy and played an important role in improving the identification efficiency and reliability of Chinese medicinal materials.It should be useful for the study of near-infrared spectroscopy identification methods of other Chinese medicinal materials.The effects of different modeling algorithms and different modeling parameters on the model analysis were studied in detail through a large number of model calculations.The effect of various factors on the qualitative analysis model was compared,and the establishment of other material qualitative analysis models is of great significance.