近红外漫反射光谱法直接测定银杏叶提取物粉末中总黄酮的含量

目的：应用近红外漫反射光谱技术和化学计量学方法，直接测定银杏叶提取物粉末中总黄酮的含量。方法：收集不同含量分布的银杏叶提取物粉末样品，以HPLC法测定其总黄酮的含量，并采集其近红外漫反射光谱数据。应用主成分分析法(PCR)、偏最小二乘法(PLS)、改进偏最小二乘法(MPLS)等回归模型对HPLC测定的结果与近红外漫反射光谱数据进行回归。经内部交叉验证，建立校正模型，进而对预测集样品进行分析。结果：MPLS建立的校正模型的准确性最佳，其预测决定系数(RQS)为0．977。对预测集样品进行外部验证，预测值与真值的相关系数(r^2)达0．973，样品回收率为96．15％—102．0％，RSD为1．1％。结论：建立了一个利用近红外漫反射光谱法直接测定银杏叶提取物粉末中总黄酮含量的新方法。该方法具有快速方便、结果准确的特点，可以应用于银杏提取过程的中间控制和大批量产品的检测。

Direct Determination of Total Flavones in Powder of Ginkgo biloba Extract by Near - infrared Diffuse Reflection Spectroscopy

Objective:To determine directly the total flavones in powder of Ginkgo biloba extract by combining near - infrared diffuse reflection spectroscopy with the chemometrics method. Methods: After collecting the powder samples with different total flavones concentrations, they were analyzed by HPLC and NIR spectra. Different regression models were used to correlate these data. Furthermore, tests of the best - fitted model with prediction samples were made. Results: MPLS( modified partial least squares) regression model best fitted the data. The multicorrelation coefficients of the prediction samples was 0. 973, the recovery was 96. 15% - 102. 0% ,with RSD of 1. 1%. Conclusions: The new method proposed could be used directly to determine the total flavones in powder of Ginkgo biloba extract with high accuracy. It is fast and convenient. There were potential applications of the method to the areas of instant analysis and on - line control of the powder production.