Solid-phase microextraction with MIL-53(Al)-polymer monolithic column coupled to pressurized capillary electrochromatography for determination of chlorogenic acid and ferulic acid in sugarcane samples

In this paper, a polymer monolithic column based on poly (Butyl methacrylate-co-ethylene glycol dimethacrylate) (poly (BMA-co-EDGMA)) doped with MIL-53(Al) metal–organic framework (MOF) was prepared using an in situ polymerization method. The characteristics of MIL-53(Al)-polymer monolithic column were studied through scanning electron microscopy (SEM), Fourier transform infrared spectrometry (FT-IR), energy-dispersive spectroscopy (EDS), X-ray powder diffractometry (XRD), and nitrogen adsorption experiment. Due to its large surface area, the prepared MIL-53(Al)-polymer monolithic column has good permeability and high extraction efficiency. Using MIL-53(Al)-polymer monolithic column for solid-phase microextraction (SPME), coupled to pressurized capillary electrochromatography (pCEC), a method for the determination of trace chlorogenic acid and ferulic acid in sugarcane was established. Under optimized conditions, chlorogenic acid and ferulic acid have a good linear relationship (r ≥ 0.9965) within the concentration range of 50.0–500 µg/mL, the detection limit is 0.017 µg/mL, and the relative standard deviation (RSD) is less than 3.2%. The spike recoveries of chlorogenic acid and ferulic acid were 96.5% and 96.7%, respectively. The results indicate that the method is sensitive, practical, and convenient. It has been successfully applied to the separation and detection of trace organic phenolic compounds in sugarcane samples.