Rapid determination of Panax ginseng by near-infrared spectroscopy

A rapid method for the simultaneous determination of the main panaxadiol saponins, panaxatriol saponins and ginseng polysaccharide in Panax ginseng was developed using near-infrared spectroscopy (NIRS). The regression models were developed using multivariate regression methods with the results from conventional chemical analytical methods as reference values. Multivariate regression methods were discussed and Partial Least Squares Regression (PLSR) was more suitable. Multiplicative scatter correction (MSC), second derivative and Savitzky-Golay smoothing were adopted together for the spectral preprocessing. The final models were evaluated by the correlation coefficient (R-2) and the root mean square error of prediction (RMSEP). The optimum RMSEP values of the panaxadiol saponins, panaxatriol saponins and ginseng polysaccharide were 0.091, 0.044 and 2.20 respectively, and the R-2 values were 0.994, 0.989 and 0.965 respectively. The results demonstrated that NIR spectroscopy could be used for the rapid determination of Ginseng Radix et Rhizoma.