Aqueous two-phase extraction technique based on magnetic ionic liquid-nonionicsurfactant for phenolic acids in grape, apple, pear, and banana

An aqueous two-phase extraction system was constituted using magnetic ionic liquid-nonionic surfactant for phenolic acids and the developed method was applied to apple, grape, pear, and banana samples. Ionic liquids based on imidazolium containing butyl, allyl, and benzyl groups were used for extraction. The parameters influencing the extraction efficiency such as volume of ionic liquids, type and amount of surfactant and salt, ultrasound extraction time, temperature, and sample pH were optimized. The extraction efficiencies of ionic liquids were compared for phenolic acids under optimized conditions. Limits of detection and limits of quantification were in the range of 1.34-1.56 μg L$^{-1\, }$and 4.33-4.68 μg L$^{-1}$, respectively. The interday and intraday precision (RSD%) for the phenolic acids at 5 and 25 μg L$^{-1\, }$were in the range of 4.48%-5.69% and 3.02%-4.51%, respectively. The spiked recoveries of phenolic acids were between 70.78% and 99.97% in real samples.