The solid-phase extraction of α-chymotrypsin based on a novel porous polymeric dianionic ionic liquid-coated magnetic material

Abstract

A novel magnetic solid-phase extraction (MSPE) method based on carboxymethylcellulose sodium modified Fe₃O₄ nanocomposite coated with porous polymeric dianionic ionic liquid (Fe₃O₄@CMC@PPDIL) was proposed and applied to extracting α-chymotrypsin. The synthesized Fe₃O₄@CMC@PPDIL was characterized by vibrating sample magnetometry (VSM), thermo-gravimetric analysis (TGA), transmission electron microscopy (TEM), X-ray diffraction (XRD), Fourier transform infrared spectrometry (FT-IR) and zeta potential measurement. Furthermore, the influence of a series of factors, such as extraction time and temperature, initial α-chymotrypsin concentration, pH value and ionic strength, was systematically investigated. Under the optimal extraction conditions, the extraction capacity for α-chymotrypsin could reach up to 122.91 mg g⁻¹, and the activity of α-chymotrypsin is well maintained after extraction. In addition, the proposed MSPE method provides satisfactory results in real sample analysis.