Dispersive solvent-free ultrasound-assisted ionic liquid dispersive liquid-liquid microextraction coupled with HPLC for determination of ulipristal acetate

The ER was all over 90.0% in three ILs and a higher ER was obtained when [C8mimPF6] was used as the extraction solvent. Adsorption capacity of three ILs for UPA was 1.99 mg g−1 ([C4mimPF6]), 9.33 mg g−1 ([C6mimPF6]) and 18.80 mg g−1 ([C8mimPF6]).269