Cyclodextrin sensitized homogeneous liquid–liquid microextraction for six hepatotoxic ingredients in “Psoraleae Fructus” based on a switchable deep eutectic supramolecular polymer

In this study, a ternary switchable deep eutectic supramolecular polymer (sDESP) based homogeneous liquid–liquid microextraction (HLLME) was established and applied to the preconcentration and determination of six main hepatotoxic ingredients in “Psoraleae Fructus” combined with high performance liquid chromatography-ultraviolet detection (HPLC-UVD). A hydrophilic switchable DESP with diethanolamine-heptanol deep eutectic solvent (DES) loaded into hydroxypropyl-β-cyclodextrin was used as an extraction solvent in the HLLME method, that could be converted into the hydrophobic form by injecting a phase-switching trigger. Then, the upper hydrophobic phase concentrating the target analytes was collected for chromatographic analysis after a centrifugation. Several key factors affecting the experiment, including the type of both DES and macrocyclic host molecule, the consumption of DESP, the type and volume of phase-switching trigger, the concentration of sodium chloride in the sample phase and extraction time were optimized. And the DESP extractant was characterized by Fourier transform infrared spectroscopy and proton nuclear magnetic resonance spectroscopy. Under the optimum conditions, the enrichment factors for six analytes by the sDESP were between 65 and 352, which were 1.1–1.2 times higher than those by pure DES. Good linearity ( r  ≥ 0.9972), low detection limits of 0.03–0.6 ng/mL, and satisfactory precisions (relative standard deviation <9.9 %) and spiked recoveries (86.7 %–100.7 %) were obtained. The hydrophilic sDESP as a novel extractant has a good extraction efficiency for six hepatotoxic ingredients in traditional Chinese medicine “Psoraleae Fructus”. This method is a promising sample pre-treatment method owing to the advantages of dispersant free, low organic solvent consumption and simple operation.