近红外漫反射光谱法测定黄芩中总黄酮及黄芩苷的含量

Determination of Baicalin and Total Flavonoids in Radix Scutellariae by Near Infrared Diffuse Reflectance Spectroscopy

文章建立了近红外漫反射光谱技术快速测定中药黄芩中主要活性成分黄芩苷和总黄酮含量的方法。对黄芩苷含量在12．24％～21．34％，总黄酮含量在16．08％～26．52％范围内的61个不同产地的黄芩，选择在8000-4000cm^-1范围内的近红外吸收光谱，采用偏最小二乘算法（PLS）比较不同光谱预处理方法建立的校正模型，结果表明一阶导数和最小最大归一化的数据预处理方法分别为黄芩苷和总黄酮最优预处理建模方法。黄芩苷校正集相关系数（r）为0．9024，校正集标准偏差（SEC）为1．01，预测集标准偏差（SEP）为0．8764；总黄酮校正集相关系数（r）为0．9527，校正集标准偏差（SEC）为0．785，预测集标准偏差（SEP）为0．5211，该方法快速简便，适合于黄芩中主要活性成分的快速分析。

The objective of the present study was to develop a method for rapid determination of baicalin and total flavonoids in radix scutellariae by near infrared diffuse reflectance spectroscopy. Sixty one samples of radix scutellariae from different areas containing baicalin of 12. 24%-21.34% and total flavonoids of 16.08%-26. 52% were used. The range of 8 000-4 000 cm-1 of near infrared spectra （NIRS） was selected. Calibration models were established using the PLS（partial least squares）. Different spectra pretreatment methods were compared and the optimal model was selected. The study showed that first derivative pretreatments and minimum-maximum normalization methods can be used to extracted spectra information thoroughly to analyze the contents of baicalin and total flavonoids, respectively. The correlation coefficient （r）of baicalin was 0. 902 4, SEC was 1.01 （standard deviation of the calibration sets） and SEP was 0. 876 4（standarddeviation ofthe prediction sets）. The correlation coefficient（r） of total flavonoids was 0. 952 7, SEC was 0. 785 0 and SEP was 0. 521 1. Results indicated that near infrared diffuse reflectance spectroscopy method can be used to analyze the main active components in radix scutellariae rapidly.