Supramolecular solvents based on deep eutectic solvents and hexafluorobutanol for the extraction of aristolochic acids from natural plants.

In this study, a new liquid phase microextraction method was developed by combining micelle-mediated extraction of aristolochic acids (AAs) in traditional Chinese medicines with polyfluorinated alcohol solutions, and subsequent preconcentration via deep eutectic solvent (DES)-induced supramolecular solvent (SUPRAS) formation. The preparation of SUPRASs with polyfluorinated alcohols functioning as amphiphiles and the DESs acting as coacervation agents is demonstrated for the first time. Different polyfluorinated alcohols and DESs were examined for the extraction and preconcentration of AAs. The SUPRAS prepared from hexafluorobutanol (HFB) and a DES based on (1) octanol:(2) fenchyl alcohol achieved the highest extraction efficiency. Compared to traditionally used surfactants such as octanol, octanoic acid, and octylamine, HFB exhibited better extraction efficiency of AAs. The optimized method provided good linearity in the range of 0.14-500 µg g-1 for AA-I and 0.1-600 µg g-1 for AA-II with determination coefficients higher than 0.9961. The limits of detection were 0.03-0.04 µg g-1, which were lower than those of the limits stipulated by the Chinese Pharmacopoeia (0.001%, w/w). The extraction recoveries ranged between 89.2 and 107.8%. The conventional methods for extracting analytes from solid samples typically involve an initial extraction phase utilizing hazardous organic solvents. The developed method can be applied to extract and preconcentrate a wide range of trace analytes from different solid samples by eliminating the need for harmful organic solvents. The developed method is efficient and reliable and can be applied to determine AAs in natural plants.