A simple,inexpensiveandsensitiveultrasonic-assistedliquid–liquidmicroextractionmethodbasedon deep eutecticsolvent(UALLME-DES)wasusedfortheextractionofthreephenolicacids(ferulic,caffeic and cinnamic)fromvegetableoils.Inatypicalexperiment,deepeutecticsolventasgreenextraction solventwasaddedton-hexane(asatypicaloilmedium)containingtargetanalytes.Subsequently,the extractionwasacceleratedbysonication.Aftertheextraction,phaseseparation(DESrichphase/n-hex- ane phase)wasperformedbycentrifugation.DESrichphase(lowerphase)waswithdrawnbyamicro- syringe andsubmittedtoisocraticreverse-phaseHPLCwithUVdetection.Underoptimumconditions obtained byresponsesurfacemethodology(RSM)anddesirabilityfunction(DF),themethodhasgood linear calibrationranges(between1.30and1000 mg L1), coefficients ofdetermination(r240.9949)and low limitsofdetection(between0.39and0.63 mg L1). Thisprocedurewassuccessfullyappliedtothe determination oftargetanalytesinolive,almond,sesameandcinnamonoilsamples.Therelativemean recoveriesrangedfrom94.7%to104.6%.
