A simple and green ultrasonic-assisted liquid–liquid microextraction technique based on deep eutectic solvents for the HPLC analysis of sesamol in sesame oils

Abstract

Sesamol is the key natural antioxidant in sesame oils, which can prevent the propagation of lipid peroxidation. A simple ultrasonic-assisted liquid–liquid microextraction (UALLME) technique based on deep eutectic solvents (DESs) was employed in the extraction of sesamol from sesame oils. In a typical experiment, 400 μL DES (choline chloride/ethylene glycol) was used as the extraction solvent and an ultrasonic-assisted extraction method was applied. After centrifugation, the DES phase containing sesamol was directly analyzed by reverse-phase HPLC with UV detection and no phase inversion was involved. The pretreatment process was simple and green owing to the use of DESs as solvent at low dosage. Under optimized conditions, sesamol showed a linear calibration curve in the range of 5–500 mg kg⁻¹ (r² = 0.9998), and a lower limit of detection (LOD) of 0.02 mg kg⁻¹. The recoveries were in the range of 97–108%, and the intra-day and inter-day precision were both less than 0.80%. This method was successfully applied to the determination of sesamol in 13 sesame oil samples. And the results were close to those of conventional liquid–liquid extraction with methanol as solvent.