.In this paper, a simple and efficient ultrasound-assisted ionic liquid dispersive liquid–liquid microextraction
(UA IL-DLLME) coupled with high-performance liquid chromatography for the analysis of
ulipristal acetate (UPA) was developed. UPA could be easily migrated into 1-octyl-3-methylimidazolium
hexafluorophosphate [C8mimPF6] IL phase without dispersive solvent. The research of extraction
mechanism showed that hydrophobic interaction force played a key role in the IL-DLLME. Several
important parameters affecting the extraction recovery were optimized. Under the optimized conditions,
25-fold enrichment factor was obtained and the limit of detection (LOD) was 6.8 ng mL1 (tablet) or
9.3 ng mL1 (serum) at a signal-to-noise ratio of 3. The calibration curve was linear over the range of
0.03–6.0 mg mL1
. The proposed method was successfully applied to the UPA tablets and the real mice
serum samples.