Ionic Liquid-based Microwave-assisted Liquid-liquid Microextraction and High Performance Liquid Chromatography Determination of Sulfonamides from Animal Oils

The authors performed ionic liquid-based microwave-assisted liquid-liquid microextraction（IL-based MALLME） coupled with high performance liquid chromatographic separation for the determination of 6 sulfonamides （SAs） from animal oils. The target analytes were extracted from animal oil samples with sodium hydroxide solution containing 1-butyl-3-methylimidazolium tetrafluoroborateand as the extraction solvent under microwave irradiation. The experimental parameters of the IL-based MALLME, including types of ILs, volume of IL, amount of ion-pairing agent（NHaPF6）, pH value of sample solution, and extraction temperature and time were evaluated. The limits of detection and quantification obtained were in a range of 0.4--0.5μg/kg and a range of 1.2--1.8μg/kg, respectively. The accuracy of the method was evaluated by analyzing five spiked animal oil samples at two fortified levels（5 and 50μg/kg）, and the recoveries of SAs varied from 81.4% to 114.5% with relative standard deviations ranging from 0.8% to 9.0%.