Selective extraction of Crocin from Saffron using modified magnetic nanoparticles coated with molecularly imprinted polymer followed by UV-Visible spectrophotometry and high-performance liquid chromatography

Abstract

Abstract Saffron is an expensive spice. One of its effective ingredients is crocin, which directly affects the quality and commercial value of saffron. Herein, a simple method has been developed based on magnetic molecularly imprinted polymers (MMIPs) for sensitive and selective extraction of crocin from saffron. MMIPs were prepared using gentiobiose as the template molecule, methacrylic acid as the functional monomer, ethylene glycol dimethacrylate as the cross-linking agent, and Fe3O4@SiO2 as the magnetic support. Nanoparticle characterizations were performed using various techniques, including Fourier-transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), scanning electron microscopy (SEM), vibrating sample magnetometry (VSM), and thermogravimetric analysis (TGA). This study investigates different parameters affecting extraction efficiency, isothermal absorption experiments, kinetics absorption experiments, and the selectivity of MMIPs. The analytes were determined by UV-Vis spectrometry and high-performance liquid chromatography (HPLC). The result showed that the sorption of crocin is described by the pseudo-second-order model, and the adsorption equilibrium data fit with the Freundlich model. Also, the sorbent had a homogeneous structure, and that the crocin sorption occurred through multilayer reversible sorption. Under the optimized conditions, the limit of detection and quantification obtained were 0.014 and 0.10 mg L− 1, respectively. The practical utility of the proposed method was evaluated via the extraction of crocin from real samples, with satisfactory results.