Dispersive liquid–liquid microextraction of phenolic compounds from vegetable oils using a magnetic ionic liquid

A novel method was developed for the determination of two endocrine‐disrupting chemicals, bisphenol A and 4‐nonylphenol, in vegetable oil by dispersive liquid–liquid microextraction followed by ultra high performance liquid chromatography with tandem mass spectrometry. Using a magnetic liquid as the microextraction solvent, several key parameters were optimized, including the type and volume of the magnetic liquid, extraction time, amount of dispersant, and the type of reverse extractant. The detection limits for bisphenol A and 4‐nonylphenol were 0.1 and 0.06 μg/kg, respectively. The recoveries were 70.4–112.3%, and the relative standard deviations were less than 4.2%. The method is simple for the extraction of bisphenol A and 4‐nonylphenol from vegetable oil and suitable for routine analysis.