Dispersive liquid-liquid microextraction with a deep eutectic solvent coupled with GC-MS for the determination of...

Carvone is an important flavoring substance and widely used in the food and chemical industries. Carvone has two optical isomers (L-carvone and D-carvone), which have different aroma characteristics. However, the green extraction of natural carvone and isolation of chiral carvone present challenges, leading to its limited application. In this study, a deep eutectic solvent (DES) was prepared and used as a green extraction solvent for the extraction of carvone from herbaceous plants, and then a chiral chromatography column combined with GC-MS was used for the separation and detection of L-carvone and D-carvone. Response surface methodology was used to optimize the extraction conditions including the volume of DES, extraction time and extraction temperature. The results showed that the extraction recoveries and intra-day precision (n = 6) were 83.5-101.3% and 3.2-6.1% when the volume of DES was 5 mL, and the extraction time and temperature were 25 min and 51 °C, respectively. The MLOD and MLOQ of L-carvone and D-carvone were 8.0 mg kg^-1 and 25.0 mg kg^-1, respectively. The real sample detection results revealed that about 235.8-1600.0 mg kg^-1 of L-carvone was detected in Mentha spicata L., and 6658.5-9788.6 mg kg^-1 of D-carvone in Anethum graveolens L. seeds. The established method can be an effective method for the detection of chiral carvone in herbaceous plants.