表面接枝亲水性聚合物刷磁性微球的制备及其对蜂蜜中四环素类抗生素残留的磁分散固相萃取

采用电子转移活化再生催化剂原子转移自由基聚合法（ARGET-ATRP）在磁性微球（MMs）表面连续接枝了聚碱类聚合物和聚乙二醇刷。首先将MMs包覆硅胶，接枝氨基，然后在其表面接枝溴引发剂，最后在MMs表面进行聚合，制备了亲水性聚合物刷磁性微球（HMMs）。通过透射电镜、傅里叶变换红外光谱对HMMs进行表征，并研究了HMMs对蛋白质的吸附性能。结果表明，合成的HMMs粒径较为均一，分散性良好并且具有良好的抗蛋白质吸附性能。利用制备的HMMs，采用磁分散固相萃取（MDSPE）-高效液相色谱法（HPLC）测定了蜂蜜中四环素类抗生素（TCs）残留。TCs的平均回收率为85.8%~94.5%，方法的检出限和定量限分别为1.92~2.56 μg/kg和6.40~8.53 μg/kg。该方法成功地用于蜂蜜中TCs残留的快速分离富集。

Preparation of hydrophilic polymer brushes magnetic microspheres by surface-initiated for magnetic dispersive solid phase extraction of tetracycline antibiotic residues from honey

Activators regenerated by electron transfer-atom transfer radical polymerization (ARGET-ATRP) was applied to the continuous grafting of polybasic polymers and poly(ethylene glycol) (PEG) brushes on the surface of the magnetic microspheres (MMs). At first, the MMs were coated with silica gel, modified by amino group, and then 2-bromoisobutyryl bromide was grafted on the surface of MMs. After that, the hydrophilic polymer brushes magnetic microspheres (HMMs) were prepared by polymerization on the surface of the MMs. HMMs were characterized by transmission electron microscope (TEM) and Fourier transform-infrared (FT-IR) spectrometer. The adsorption performance to protein was studied. The results demonstrated that HMMs have the relatively uniform particle size, good dispersity and excellent protein resistance properties. Tetracycline antibiotics (TCs, tetracycline hydrochloride, chlortetracycline hydrochloride and doxycycline hydrochloride) in honey samples were determined by magnetic dispersion solid phase extraction (MDSPE) using the prepared HMMs and high performance liquid chromatography (HPLC). The average recoveries were obtained in the range of 85.8%-94.5%. The limits of detection (LODs) and limits of quantification (LOQs) of the proposed method were in the ranges of 1.92-2.56 μg/kg and 6.40-8.53 μg/kg, respectively. The proposed method was successfully applied to fast clean-up and enrichment of the TCs residues in honey.