Angelica dahurica, a traditional medicinal and food homology plant, belongs to the Umbelliferae family and was documented in the first section of the 2020 edition of the Chinese Pharmacopoeia [1]. In addition to its medicinal value, Angelica dahurica is very commonly used as a flavor enhancer in cooking, such as in stewed meat and fish, to remove the fishy smell and enhance the aroma in almost every household, especially in northern China. Currently, a health tea of Angelica dahurica has been developed to dissipate heat, detoxify, moisten the lungs, and relieve coughs [2]. Among the main chemical components of Angelica dahurica (coumarins, volatile oils, alkaloids, polysaccharides, flavonoids), coumarins are the main active ingredients with contents ranging from 0.211 %−1.221 % [3], playing the roles of strengthening stomach and promoting good digestion. Imperatorin is the most abundant coumarin compound in Angelica dahurica [4], which was selected as the indicator for content determination and stipulated the content should be >0.08 % in Chinese Pharmacopoeia. In the food and medicine production process, rapid separation and purification of target ingredients are the key points to quality control. At present, the methods for extracting coumarins from Angelica dahurica include solvent extraction [5], microwave-assisted extraction [6], ultrasonic extraction [7], and supercritical CO2 extraction [8]. Because of the low content and uneven distribution of coumarins in Angelica dahurica, traditional extraction methods such as solvent extraction resulted in low efficiency and purity. If organic solvents are used, it will lead to high toxicity and residue problems, affecting product safety. Ultrasound and microwave-assisted extraction have high energy consumption and may cause damage to thermally unstable components. Supercritical CO2 extraction requires expensive equipment and precise control of process parameters, making it difficult to industrialize. Therefore, developing a highly selective method for extracting and detecting a certain type of trace analyte in traditional Chinese medicine and food is a challenging task.

Molecularly imprinted polymers (MIPs), as effective materials for purifying and enriching trace target components from complex matrices [9], are widely used in medicine, food, and environmental monitoring. In recent years, the combination of magnetic nanoparticles and MIPs (MMIPs) has greatly simplified the pretreatment process of samples. Compared with traditional MIPs, MMIPs have more advantages of larger surface area, better biocompatibility, easier operation and functionalization [[10], [11], [12]], which can significantly shorten the detection time to rapidly extract target compounds and screen the unqualified product. MMIPs not only can efficiently adsorb target components, but also can be reused, making it suitable for large-scale food testing and industrial applications. However, there are few reports on MMIPs techniques for the accurate extraction of coumarins, Kuang et al. constructed a magnetic surface molecularly imprinted polymer using 4-hydroxycoumarin as a template molecule, with an adsorption capacity of up to 22.78 mg·g−1 [13]. In this study, a novel magnetic nanoparticles were used as carriers to synthesize MMIPs materials with higher selectivity and greater adsorption capacity using imperatorin, isoimperatorin, and oxypeucedanin as templates for the first time.

In order to improve efficiency, we used computer simulation to evaluate functional monomer and template combinations. By comparing their simulation parameters, we simulate the molecular forces between coumarins and functional monomers and predict the optimal binding site and binding energy [14]. Weak binding functional monomers were eliminated priorly while High affinity monomers were directly locked. The optimal molar ratio of functional monomers and template monomer complexes in the molecular imprinting system was determined using UV. To verify the accuracy of the computer and UV results, adsorption experiments were performed, and the results were in perfect agreement with both. Subsequently, we synthesized a multitemplate MMIP by surface imprinting using 4-VP as a functional monomer and imperatorin, isoimperatorin, and oxypeucedanin as templates (1:4). SEM, FT-IR, BET, TGA, VSM, and XRD were subsequently used to characterize the samples, and adsorption experiments were carried out to evaluate their adsorption efficiency and specificity. In this study, magnetic solid-phase extraction-high-performance liquid chromatography (MSPE-HPLC) was used for the first time to efficiently extract coumarins. It not only provides a reference method for the development of magnetic multitemplate imprinted polymers but also compensates for the shortcomings encountered in the efficient extraction and purification of imperatorin, isoimperatorin, and oxypeucedanin from Angelica dahurica, which lays the foundation for the application of MSPE technology in the extraction of coumarins from traditional Chinese medicine and food.