Bilobalide molecularly imprinted polymers prepared using MWCNTs/ZIF‐67 composite as supporter for solid‐phase extraction of bilobalide from real samples

Abstract

AbstractThe preparation of raw materials is an important prerequisite for studying the function of natural active ingredients. Here, the preparation of MWCNTs/ZIF‐67@MIPs based on surface molecular imprinting technology for the separation of bilobalide (BB) from real samples was proposed. The successful preparation of MWCNTs/ZIF‐67@MIPs was demonstrated using several techniques. Adsorption equilibrium was achieved when the time was 4 h, and the rate of adsorption calculated from the dynamic adsorption results was 14.2 μg mL–1 h–1. The maximum adsorption amount for MWCNTs/ZIF‐67@MIPs of BB was calculated to be 59.2 mg g–1, which was more than three times that for MWCNTs/ZIF‐67@NIPs (23.1 mg g–1), and the Freundlich isotherm model and pseudo‐second‐order kinetic model were more suitable for the explanation of isothermal and kinetic adsorption behaviors, respectively. The results of selective adsorption indicated that MWCNTs/ZIF‐67@MIPs show excellent selectivity and specificity for BB compared to structurally similar compounds such as ginkgolides A, B and C, with an excellent imprinting factor (2.83). The results of reuse studies indicated that MWCNTs/ZIF‐67@MIPs exhibited great reproducibility with a recovery rate of 70.8% after repeated use for five times. Finally, the developed MWCNTs/ZIF‐67@MIPs were used as a solid‐phase extraction sorbent to directly separate BB from treated gingko leaf extract and crude extract of BB, and the results suggested that the purity of BB in the two samples was increased by about 30%, and the recoveries reached 68.34% and 71.54%, respectively. Meanwhile, the separation effect of MWCNTs/ZIF‐67@MIPs on BB was better than that of BBMIP prepared by bulk polymerization. © 2021 Society of Industrial Chemistry.