Deep eutectic solvent-based liquid-liquid microextraction for the HPLC-DAD analysis of bisphenol A in edible oils

A sample preparation method for the extraction of bisphenol A (BPA) from edible oils was established via simple, green, and sensitive deep eutectic solvent-based liquid-liquid microextraction (DES-LLME) before high-performance liquid chromatography (HPLC) with diode array detector (DAD). The deep eutectic solvent (DES) formed by tetrabutylammonium bromide (TBAB) and methanol was acted as the extractant. All parameters in the DES-LLME step, including the type and volume of extractants, the extraction time, and centrifugation time, were investigated and optimized. The application of hydrophilic DES in oils expands the selection of LLME extractants. Under the optimized conditions, the calibration curves in the range of 10–500 ng g −1 with a correlation coefficient of r  > 0.999, and the detection limit was 0.8 ng g −1 . The relative standard deviations of intra-day and inter-day repeatability were 4.3% and 6.2%, respectively, and the recoveries varied between 88.7% and 97.3%. This developed method was successfully employed for measuring BPA in 6 edible oil samples.