SEPARATION SCIENCE AND TECHNOLOGY, vol.57, no.3, pp.433-443, 2022 (SCI-Expanded)
Polyethylene glycol bis (methylimidazolium) ditetrachloroferrate was synthesized and used as adjuvant in aqueous two-phase system based on polymer-salt for the extraction of gallic acid, protocatechuic acid, chlorogenic acid, caffeic acid, and ferulic acid. Ultrasound-assisted aqueous two-phase system was consisted by polyethylene glycol 600 and sodium carbonate and ionic liquid as adjuvant. Polymer-ionic liquid-salt-based aqueous two-phase system was optimized with parameters including amount of ionic liquid and polymer, type and amount of salt, extraction time, extraction temperature, and pH of phenolic acid solution. The optimal conditions were defined as follows: 5% (v/v) ionic liquid, 0.7 g polyethylene glycol 600, 0.5 g sodium carbonate, 20 min extraction time, 40 degrees C extraction temperature, and sample solution at pH 5. The satisfactory method was successfully implemented for the extraction and determination of phenolic acids in grape, apple, banana, and pear samples with recoveries in the range of 84.30-100.00%.