[Quality Evaluation of Rhei Radix et Rhizoma Based on SPE and HPLC Characteristic Chromatogram with An Internal Standard].

Objective: To establish a quality evaluation method for Rhei Radix et Rhizoma based on SPE and internal standard HPLC characteristic chromatogram.

Methods: Using water reflux extraction and SPE methods, the total Rhei Radix et Rhizoma anthraquinones were obtained. By HPLC method, the characteristic chromatogram of Rhei Radix et Rhizoma was established,and the qualitative research was performed with DAD and MSn. Relative area of the characteristic peaks in the samples was calculated by the addition of an internal standard to evaluate the quality of Rhei Radix et Rhizoma.

Results: The results showed that the optimum condition were as follows,the solid-liquid ratio was 1∶ 150; the extraction time was 60 min. SPE optimum condition for the introduction of Accu BOND Ⅱ SPE ODS-C18 Cartridges SPE were as follows, the loaded concentration was 1 m L, the SPE column was rinsed twice with 3 m L 0. 3% formic acid, then rinsed with 3 m L 25% methanol( containing 0. 3% formic acid) and finally eluted with 3 m L of methanol. The recovery rate was 96. 3% ~ 103%. With 5-hydroxymethylfurfural as an internal standard, the characteristic chromatogram was established, and twelve peaks were selected as characteristic peaks. In ten batches of samples, the RSD of relative retention time was < 3%,and the relative area of the characteristic peaks were calculated. The principal component analysis and cluster analysis with the results of the Chinese Pharmacopoeia( 2015 edition),which indicated that the characteristic chromatogram could reflect the anthraquinones in Rhei Radix et Rhizoma, and distinguish the Rheum palmatum, Rheum tanguticum and Rheum officinale.

Conclusion: It is concluded that the established method is simple,fast and specific, which can provide a reference for the evaluation of the quality of Rhei Radix et Rhizoma.