liquid–liquid microextraction based on acid–base-induced deep eutectic solvents for determination of β-carotene and lycopene in fruit juices

An uncomplicated, valid, and convenient way for detection of lycopene and β-carotene in fruit juice samples using acid–base-induced deep eutectic solvent (des) liquid-liquid microextraction (des-abllme) prior to hplc was developed. the ternary fatty acid dess were prepared by c9:c10:c11 (2:1:1), which serve as hydrogen bond donors and hydrogen bond acceptors synchronously. in extraction procedure, nh3·h2o was used as the emulsifier and reacted with dess with a milk solution, which can significantly increase the extraction efficiency. hcl was used as the de-emulsifier, which could break the state of emulsification. at optimum conditions, the calibration graphs were linear in the concentration range from 0.1 to 100 μg ml−1 for lycopene and from 0.025 to 5.00 μg ml−1 for β-carotene. the limits of detection (lods) were 0.05 and 0.002 μg ml−1 for lycopene and β-carotene, respectively. the rsd values were varied from 1.3 to 4.1%. finally, the proposed method was applied to analyze β-carotene and lycopene in fruit juices.