Application of ionic liquids in vacuum microwave-assisted extraction followed by macroporous resin isolation of three flavonoids rutin, hyperoside and hesperidin from Sorbus tianschanica leaves

• Hesperidin, hyperoside and rutin were first extracted by ionic liquids solution.
• 1-Hexyl-3-methylimidazolium tetrafluoborate was as extracting solvent.
• Ionic liquid-based vacuum microwave-assisted extraction was developed.
• The proposed approach was confirmed by good recovery and reproducibility.
• Macroporous resin was attempted for separation target analytes from IL solution.

Rutin, hyperoside and hesperidin were effectively extracted from Sorbus tianschanica leaves by an ionic liquid vacuum microwave-assisted method. A series of ionic liquids with various anions and alkyl chain length of the cations were studied and the extraction was performed in [C6mim][BF4] aqueous solution. After optimization by a factorial design and response surface methodology, total extraction yield of 2.37 mg/g with an error of 0.12 mg/g (0.71 ± 0.04 mg/g, 1.18 ± 0.06 mg/g and 0.48 ± 0.02 for rutin, hyperoside and hesperidin, respectively) was achieved under −0.08 MPa for vacuum, 19 min and 420 W for microwave irradiation time and power, and 15 mL/g for liquid–solid ratio. The proposed method here is more efficient and needs a shorter extraction time for rutin, hyperoside and hesperidin from S. tianschanica leaves than reference extraction techniques. In stability studies performed with standard rutin, hyperoside and hesperidin, the target analytes were stable under the optimum conditions. The proposed method had a high reproducibility and precision. In addition, separation of rutin, hyperoside and hesperidin from [C6mim][BF4] extraction solution was completed effectively by AB-8 macroporous resin adsorption and desorption process. Ionic liquid vacuum microwave-assisted extraction is a simple, rapid and efficient sample extraction technique.