Ionic liquid-immobilized NaY zeolite-based matrix solid phase dispersion for the extraction of active constituents in Rheum palmatum L.

The ionic liquid-immobilized NaY zeolite was prepared by means of impregnation approach and used as the dispersant of matrix solid phase dispersion for the extraction of aloe-emodin, emodin, chrysophanol and physcion in Rheum palmation L. High performance liquid chromatography coupled with diode-array detection was used for the separation and determination of target analytes. The ionic liquid-immobilized NaY zeolite was further characterized by SEM, FT-IR, TG, XRD and BET. The experimental parameters, such as type and content of ionic liquid, mass ratio of sample to dispersant, type of washing solvent, and type and volume of elution solvent, were optimized. The results revealed that the prepared ionic liquid-immobilized NaY zeolite presents suitable properties and can be used as the dispersant of matrix solid phase dispersion for the extraction of anthraquinones. Good linearities (r > 0.9995) were obtained in the range of analyte concentration investigated. The recoveries were 73-98% with the relative standard deviations lower than 6%. Compared with ultrasound-assisted extraction and heat reflux extraction, the present method requires less sample, organic solvent and extraction time. The present method can be applied to the determination of anthraquinones from medicinal plant.