Selective adsorption and determination of doxorubicin and epirubicin in plasma using magnetic molecularly imprinted polymers combined with HPLC-UV

Magnetic molecularly imprinted polymers (MMIPs) were synthesized using magnetic Fe₃O₄@SiO₂ as a carrier for the selective recognition and adsorption of doxorubicin (DOX) and epirubicin (EPI) in plasma. Then, the method was combined with high-performance liquid chromatography-ultraviolet detection (HPLC-UV) to realize rapid and accurate detection of DOX and EPI concentrations in plasma. The structures of the prepared MMIPs were characterized by X-ray diffraction, transmission electron microscopy, X-ray photoelectron spectroscopy, and magnetic saturation. As observed, the prepared MMIPs had a uniform appearance and excellent magnetic properties. Then, the adsorption performance of MMIPs was verified through static, dynamic, and selective adsorption tests. MMIPs were found to have high adsorption capacity (8.36 and 8.19 mg g⁻¹), high selectivity (imprinting factors of 34.83 and 8.03), and rapid adsorption for DOX and EPI, respectively. Next, HPLC-UV was used for quantitative analysis. The prepared method had a good linear relationship (0.0001–0.5 mg mL⁻¹ for DOX and 0.0002–0.5 mg mL⁻¹ for EPI) and low detection limits (0.04613 ng mL⁻¹ for DOX and 0.08969 ng mL⁻¹ for EPI). The combination of magnetic solid-phase extraction and HPLC-UV was a highly specific and sensitive method for determining DOX and EPI concentrations in plasma.