Rapid Determination of Total Content of Five Major Anthraquinones in Rhei Radix et Rhizoma by NIR Spectroscopy / 中草药·英文版

ABSTRACT

Objective To establish a new method with near-infrared (NIR) spectroscopy to determine the total content of emodin, chrysophanol, rhein, aloeemodin, and physcion. NIR was used in this study to provide rapid and nondestructive analysis results. Methods In the first place, HPLC was used to measure the total content of emodin, chrysophanol, rhein, aloe-emodin and physcion in Rhei Radix et Rhizoma (RR) as a reference. In the second place, the spectral regions, regression methods, pretreatment methods, and partial least squares (PLS) factors were compared to increase the feasibility of the model. In the last, the root mean square error of calibration (RMSEC), root mean square error of cross validation (RMSECV), root mean square error of prediction (RMSEP), and correlation coefficient (r) were used as assessment parameters. Results PLS with first derivative pretreatment in the ranges of 4242-5581 cm−1, 5885-6233 cm−1 and 6394-7011 cm−1 provided the best results. The RMSEC and RMSEP obtained were 0.134 and 0.226 respectively. The according determination coefficients of the quantitative model were 0.99 and 0.94. Conclusion NIR spectroscopy as a quick and nondestructive analytical method may be used to determine the total content of emodin, chrysophanol, rhein, aloeemodin, and physcion for the quality control of RR.