Micellar Extraction and Preconcentration of Anthraquinone Derivatives from Rhubarb Prior to Their HPLC‐DAD Determination

Abstract

In this paper, the nonionic surfactant, oligoethylene glycol monoalkyl ether (Genapol X‐080), was employed for the micellar extraction and preconcentration of the five anthraquinone derivatives from rhubarb prior to HPLC analysis. Various experimental conditions were investigated to optimize the extraction process. Under optimum conditions, i.e., 10% Genapol X‐080 (w/v), liquid/solid ratio of 50:1 (mL · g⁻¹), ultrasonic assisted extraction for 45 min, the extraction yield of anthraquinone derivatives reached the highest value. For the preconcentration of anthraquinone derivatives by cloud point extraction (CPE), the solution was incubated in a thermostatic water bath at 55°C for 45 min, and 0.24 g ·  mL⁻¹ sodium sulfate was added to the solution to facilitate the phase separation and increase the preconcentration factor during the CPE process. Compared with commonly used organic solvents, 10% Genapol X‐080 has the highest extraction yield of anthraquinone derivatives. The micellar extraction and preconcentration method established in this paper is demonstrated to be a simple and effective environment friendly alternative to conventional organic solvent extraction methods.

Keywords:

• Micellar extraction and preconcentration
• Cloud point extraction
• Genapol X‐080
• Anthraquinone derivatives
• High performance liquid chromatography

Acknowledgments

Financial support from the National Natural Science Foundation of China (No.20575016) and the Natural Science Foundation of Hebei Province China (No. B2006000953) are gratefully acknowledged. The authors also thank the financial support from ‘the introduction of talents’ programme of Hebei University.