Epimedium is a famous medicinal plant in China. Total flavonoids in Epimedium exhibit a wide variety of bioactivities. We developed an analytical method based on near-infrared reflectance spectroscopy for determining total flavonoids in Epimedium and measured the content of total flavonoids in 7 Epimedium species. The best calibration model was under the following conditions: 2 nd derivative, principal components analysis, weighted multiplicative scatter correction and modified partial least squares regression. The coefficient of determination for calibration, standard error of cross-validation and coefficient of determination for cross-validation of prediction equation of calibration set were 0.985 5, 0.023 0 and 0.044 3, respectively. The coefficient of determination, standard error of performance and bias of prediction equation of validation set were 0.965 1, 0.018 and 0.006, respectively. These results confirmed the good predictability of the model. The analytical method can be efficiently used for rapid quantification of total flavonoids in Epimedium.

Near-infrared reflectance spectroscopy was used for rapid and nondestructive determination of proteins in Epimedium. The calibration model was developed under the following conditions: second-derivative, standard multiplicative scatter correction, principal component analysis and modified partial least-squares regression. R squared, standard error of cross-validation and 1 minus variance ratio values were 0.923, 0.554 and 0.717, respectively. Protein content did not differ by near-infrared reflectance spectroscopy or Kjedahl nitrogen determination methods, and their relationship was close (R 2 =0.933 9). The proposed near-infrared reflectance spectroscopy method is a simple analytical technique with satisfactory accuracy and repeatability (RSD=0.937%). Protein content in 8 species of Epimedium were determined by near-infrared reflectance spectroscopy. The method shows great potential for protein assay in quality control and resource utilization of Epimedium.