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    聚多巴胺磁性分子印迹聚合物的制备及其在测定食品中玉米赤酶烯酮上的应用

    Preparation of Magnetic Molecularly Imprinted Polymers Based on Polydopamine and Its Application of Determination for Zearalenone in Food

    • 摘要: 采用表面分子印迹技术,以四氧化三铁纳米粒子(Fe3O4 NPs)为磁核,槲皮素为模拟模板分子,多巴胺(DA)为功能单体和交联剂,一步法制备了Fe3O4磁性分子印迹聚合物(Fe3O4@PDA MIPs)。采用透射电子显微镜和傅里叶变换红外光谱仪对该磁性分子印迹聚合物进行了表征,并采用等温吸附曲线考察了其对玉米赤酶烯酮的吸附性能。结果显示,该磁性分子印迹聚合物对玉米赤酶烯酮的吸附方式符合Langmuir模型,且最大吸附容量为1.49 mg·g-1。以Fe3O4@PDA MIPs为分散固相萃取剂,优化了Fe3O4@PDA MIPs用量、溶液酸度、超声萃取时间、解吸溶剂种类和解吸方式等萃取参数,并结合高效液相色谱-荧光检测法测定食品中玉米赤酶烯酮的含量。优化的试验条件如下:用体积比为9:1的乙腈-水的混合液100 mL对已粉粹混匀的40.0 g样品超声提取30 min,过滤,分取20 mL提取液于顶空瓶中,氮气吹至近干,再分别加入30 mg Fe3O4@PDA MIPs和10 mL水,超声萃取5 min,采用2 mL乙腈解吸2次(每次1 mL)的方式进行解吸,分取0.5 mL解吸液于1.5 mL进样瓶中,加入0.5 mL水,供高效液相色谱法测定。结果表明,玉米赤酶烯酮的质量浓度在1~20 μg·L-1内与对应的峰面积呈线性关系,检出限(3S/N)为0.68 μg·L-1。按照标准加入法进行回收试验,回收率为80.1%~101%,测定值的相对标准偏差(n=5)为5.0%~8.6%。此外,该磁性分子印迹聚合物具有良好的稳定性,至少可重复使用7次。

       

      Abstract: Using Fe3O4 nanoparticles (Fe3O4 NPs) as the magnetic core, quercetin as the mimic template molecule and dopamine (DA) acted as the functional monomer and cross-linker, the magnetic molecularly imprinted polymers (Fe3O4@PDA MIPs) were prepared by surface molecular imprinting technology based on a one-pot method, which was characterized by a transmission electron microscopy and a Fourier transform infrared spectrometer. And its adsorption performance for zearalenone was evaluated by the isothermal adsorption curve. It was shown that this magnetic MIPs were displayed maximum adsorption capacity to be 1.49 mg·g-1 for zearalenone, and the process matched the Langmuir model. Fe3O4@PDA MIPs was used as an adsorbent of dispersive solid phase extraction, and the extraction parameters including the amount of Fe3O4@PDA MIPs, solution acidity, ultrasonic extraction time, desorption solvent type and desorption method, were optimized, which was applied to the determination of zearalenone in food samples combined with high performance liquid chromatography (HPLC)-fluorescence detector. The optimal experimental conditions were as follows:The sample uniformly shattered (40.0 g) was extracted ultrasonically for 30 min with 100 mL of the mixed solution of acetonitrile and water at the volume ratio of 9:1. After filteration, an aliquot (20 mL) of the extract was placed into a headspace vial and blown to near dryness by nitrogen. 30 mg of Fe3O4@PDA MIPs and 10 mL of water were added in sequence for ultrosonic extraction for 5 min. Then 2 mL of acetonitrile were used to desorb zearalenone from the MIPs twice (each 1 mL). An aliquot (0.5 mL) of desorption solution was taken and placed into a 1.5 mL-injection bottle. 0.5 mL of water was added into the above solution for HPLC determination. As shown by the results, linear relationship between values of peak area and mass concentration of zearalenone was found in the range of 1-20 μg·L-1, with detection limit (3S/N) of 0.68 μg·L-1. Test for recovery was made by standard addition method, giving results in the range of 80.1%-101%. Moreover, the magnetic MIPs had good stability and could be reused at least 7 times.

       

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