近红外光谱法快速测定茯苓药材水分

Studies on Rapid Quantitative Analysis of the Water in Poria Cocos by Near Infrared Diffuse Reflectance Spectroscopy

目的:利用近红外漫反射技术和化学计量学的方法对茯苓药材的水分进行快速定量分析。方法:用积分球漫反射光谱采样系统测定样品的近红外漫反射光谱,定量模型的预处理方法为多元散射校正(MSC)和一阶微分处理,波长范围为5 924～5 789cm-1、5 172～4 798cm-1和4 493～4 323cm-1,回归方法为偏最小二乘法(PLS)。结果:定量模型的最佳主因子数为8,内部交叉验证均方差RMSECV为0.453,决定系数R2为0.998,外部验证预测均方差RMSEP为0.366,系统精密度RSD为1.3%,方法精密度RSD为2.2%。结论:建立预测模型对茯苓药材的水分进行测定是可行的,该法分析快速简便,结果准确。

Objective：Near infrared diffuse reflectance spectroscopy（NIRS） and chemometrics techniques were used for the rapid quantitative analysis of the water in Poria cocos.Methods： Near infrared spectra of the samples were measured by the integrating sphere.The partial least squares（PLS） calibration model was built with the first derivative spectra in the ranges of 5 924.25~5 789.26,5 172.15~4 798.02 and 4 493.33~4 323.62cm-1,which were normalized by multiplicative scatter correction（MSC） first.Results：The optimal number of the latent variables for the model was 8.The coefficient of determination（R2） for the model is 0.998.The root mean square error of cross-validation（RMSECV） was 0.453 and root mean square error of prediction（RMSEP） was 0.366.The relative standard deviation of the system and the method was 1.3% and 2.2%,separately.Conclusion： The NIRS model was proved to be a rapid and exact method for the quantitative determination of the water in Poria cocos.