Application of ionic liquid-based surfactants in the microwave-assisted extraction for the determination of four main phloroglucinols from Dryopteris fragrans.

An ionic liquid-based surfactant combined with microwave-assisted extraction method, followed by RP-HPLC-diode array detection (DAD) with a core shell column, was successfully applied in extracting and quantifying four major phloroglucinols from Dryopteris fragrans. Eight ionic liquids with different cation and anion were investigated, and 1-octyl-3-methylimidazolium bromide presented the best relative extraction efficiency for four phloroglucinols. The optimum conditions of this method were as follows: ionic liquid concentration 0.75 M, liquid/solid ratio 12:1 mL/g, extraction time 7 min, extraction temperature 50°C, and irradiation power 600 W. The quality analytical parameters of the method were obtained based on the linearity, precision, accuracy, detection, and quantification limits. The recoveries were between 96.90 and 103.5% with standard deviations not higher than 4.7%. Compared with ionic liquid-based heat reflux extraction, ultrasonic-assisted extraction, negative-pressure cavitation extraction, and conventional microwave-assisted extraction, the relative extraction efficiencies of the proposed method for four phloroglucinols increased 1.5-40.4%. The method was successfully applied for the quantification of four major phloroglucinols from D. fragrans. All these results suggest that the developed method represents an excellent alternative for the extraction and quantification of phloroglucinols in other plant materials.