In situ ionic liquid-assisted mechanochemical extraction and aqueous two-phase system enrichment of hydrophobic flavonoids from rose

Abstract

An effective in situ ionic liquid-assisted mechanochemical extraction (MCE) and aqueous two-phase system (ATPS) enrichment method was established. An ATPS can be formed to accomplish the enrichment of the compounds while realizing the MCE for medicinal crop, aiming to establish a pretreatment method for quantitative analysis of active compounds in complex matrices. The effects of ionic liquid amount, milling time, salt amount, vortex time and pH value were investigated, and the optimal conditions for the response surface method were obtained as follows: 1-butyl-3-methylimidazolium bromide amount of 250.37 mg, milling time of 1.99 min and salt amount of 4.38 g. After obtaining the optimal conditions, the method has the correlation coefficients of 0.9963–0.9996, and the limits of detection for the analytes were ranged from 0.05 to 0.08 ng/mL. Besides, the recoveries of rose samples were 84–119% at spiked levels of 0.1 and 1 µg/mL. Compared with other extraction methods, this method synchronously combines MCE and ATPS enrichment techniques, which is environmentally friendly and shortens the extraction time, and can effectively extract hydrophobic flavonoids from roses without any organic solvents.