Simultaneous extraction of anthracyclines from urine using water-compatible magnetic nanoparticles with a dummy template coupled with high performance liquid chromatography

Water-compatible magnetic molecularly imprinted polymers (M-MIPs) for extraction and pre-concentration of anthracyclines (ANTs) from urine have been successfully synthesized by a non-covalent method using epirubicin (EPI) as a dummy template, methacrylamide as a functional monomer, and ethylene glycol dimethacrylate as a cross-linker. The obtained M-MIPs were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD) and vibrating sample magnetometer (VSM). Adsorption kinetic and isotherm studies were carried out, which indicated that the M-MIPs displayed a rapid dynamic process and a high adsorption capacity. The adsorption behavior was discussed in detail, showing that it could be described as a chemisorption process and both external surface diffusion and intra-particle diffusion contributed to the adsorption mechanism. Furthermore, the binding sites were found to be heterogeneous for M-MIPs, while homogeneous for M-NIPs. The selectivity of M-MIPs demonstrated higher affinity for target EPI and EPI-analogues over other structurally unrelated compounds. A rapid solid-phase extraction (SPE) method using M-MIPs as sorbents coupled with high performance liquid chromatography (HPLC) was established for simultaneous determination of ANTs in urine samples. The recoveries ranged from 93.9% +/- 5.2% to 100.0% +/- 3.4% with the limit of detection of 0.6-2.4 ng mL(-1). Moreover, the M-MIPs could be regenerated, which could be utilized for several cycles with no obvious decrease in the adsorption capacity. The results indicated that the proposed method is a practical approach for simultaneous determination of ANTs in urine.