An efficient extraction method for essential oil from angelica sinensis radix by natural deep eutectic solvents-assisted microwave hydrodistillation

As a sustainable green new solvent, natural deep eutectic solvent (NADES) has good application potential in extraction of natural products. In this study, NADES-assisted microwave hydrodistillation (NADES-A-MHD) was used to extract essential oils from Angelica sinensis Radix. By studying the different NADESs, it was found that choline chloride and citric acid were more beneficial for extraction of essential oil. In addition, it was compared to hydrodistillation (HD), microwave hydrodistillation (MHD) and natural deep eutectic solvent-assisted hydrodistillation (NADES-AHD). The composites of the essential oils were analyzed by gas chromatography-mass spectrometry (GC-MS), the results showed that NADES-A-MHD obtained the highest yield of essential oil; it also has the highest content of ligustilide, which is the main component of Angelica sinensis essential oil. Further, the response surface methodology was used to optimize the extraction conditions of essential oil and a molar ratio of 1:3, a microwave power of 600 W and the water content of 40% was the best condition. The average yield of essential oil was 1.39%. This work developed a new and efficient NADES-A-MHD based extraction method for essential oils.