Study On Quality Control Of Lianqiao (Fructus Forsythiae) By Near-infared Spectroscopy

In this paper, Near-Infared (NIR) spectroscopy method was applied in the quality control of Lianqiao. There are two parts in this program:Firstly, NIR spectroscopy method was used for rapid discrimination of geographical origins of Chinese herb with Lianqiao (Fructus Forsythiae) as an example. NIR diffuse reflectance spectra of 60 samples of Lianqiao from Henan,Shanxi and Shaanxi provinces were collected and analyzed by two methods: clustering analysis and discriminant analysis. In the former, second derivative and Norris smoothing were utilized together to correct the scattering effect and eliminate the baseline shift in the range of 4092～8008 cm-1 in order to give a better classification on Lianqiao from different geographical origins; the latter method was used to establish a discriminant analysis model which can be used to identify the geographical origin of Lianqiao. It is shown that the correct rate of the internal cross-validation identification was 98.33%. By the model, 12 samples were analyzed, and the prognostications of their geographical origins were exact on the whole. It is indicated that NIR method is simple, accurate and can be used in rapid discrimination of herbal medicines from different geographical origins.The second part is to creat a new method that can directly determine four components of Lianqiao by Near-infrared spectroscopy combined with chemometrics methods. First, the standard methods, such as the method indexed by"Chinese Pharmacopoeia",were used to determine the contents of Moisture,Ethanol-extracted,Phillyrin and and Forsythoside A from 103 samples of Lianqiao. At the same time, NIR diffuse reflectance spectra of 103 samples were collected.Then, Partial Least-Squares (PLS) method was used to create a quantitative model of calibration. It is shown that the the root-mean-square error of cross-validation (RMSECV) of the Moisture,Ethanol-extracted,Phillyrin and and Forsythoside A are 0.59,1.78,0.36 and 0.19, the correlation coefficients are 0.964,0.966,0.962 and 0.989, the average recycle rate are 97.21%,100.42%,102.82% and 106.41%. Statistical test was used to analysis the dates and it's shown that the difference between NIR prediction values and the values determinated by standard methods has no statistical significance, It is indicated that NIR method is simple and can be used in rapid determination of the contents of Lianqiao.The above study shows that NIR method can be used to identify the geographical origins of Lianqiao rapidly and determinate multiple contents of Lianqiao accurately without complex pretreatment or long analysis time. It has the significant advantages which the traditional chemical analysis method doesn't have, and it's suitable for on-line quality control in the process of pharmaceutical production. Therefore, NIR method has great prospects in the process of modernization of traditional Chinese medicine.