ZIF-8@Fe3O4磁性固相萃取结合高效液相色谱法测定果汁中3种苯甲酰脲杀虫剂

发展了磁性沸石咪唑酯骨架材料(ZIF-8@Fe3O4)磁性固相萃取结合高效液相色谱-二极管阵列检测器,测定果汁中氟幼脲、四螨嗪和氟啶脲3种苯甲酰脲杀虫剂(BUs)的新方法。利用X射线衍射仪、傅立叶变换红外光谱仪、扫描电子显微镜和振动样品磁强计对合成的ZIF-8@Fe3O4吸附剂进行表征,考察了溶液pH值、吸附剂用量、吸附时间、洗脱溶剂种类和体积(单次洗脱体积×洗脱次数)对BUs萃取效率的影响。在最优实验条件下,氟幼脲和四螨嗪在2.0~200 ng/mL、氟啶脲在3.5~350 ng/mL范围内线性关系良好(相关系数r=0.999),检出限(S/N=3)和定量下限(S/N=10)分别为0.6~1.0 ng/mL和2.0~3.5 ng/mL。3个加标水平下的回收率为82.7%~98.6%,日内和日间(n=3)相对标准偏差(RSD)分别为1.2%~6.1%和1.3%~9.0%。当上样体积为10 mL时,ZIF-8@Fe 3O 4对果汁中3种BUs的富集倍数为43.4~48.1倍,吸附剂重复使用10次后,3种BUs回收率的RSD不大于8.8%。该方法灵敏、高效,可用于果汁样品中BUs的分析。

Determination of 3-Benzoylurea Insecticides in Fruit Juice by High Performance Liquid Chromatography with ZIF-8@Fe3O4 Based Magnetic Solid phase Extraction

A high performance liquid chromatography with magnetic zeolitic imidazolate framework(ZIF-8@Fe3O4)solid-phase extraction was developed for the determination of three benzoylurea insecticides(BUs),i.e.penfluron,clofentezine and chlorfluazuron in fruit juice samples.The prepared ZIF-8@Fe3O4 sorbent was characterized by X-ray diffraction,Fourier transform infrared spectrometry,scanning electron microscopy and vibrating sample magnetometry.The extraction parameters were optimized,including pH value of solution,amount of sorbent,extraction time,eluting solvent type and volume(single elution volume×elution times).Under the optimized conditions,there were good linear relationships in the range of 2.0-200 ng/mL for penfluron and clofentezine and 3.5-350 ng/mL for chlorfluazuron,with correlation coefficients(r)of 0.999.The limits of detection(S/N=3)for three analytes were in the range of 0.6-1.0 ng/mL,and the limits of quantitation(S/N=10)were 2.0-3.5 ng/mL.The recoveries for all targets at three spiked levels in fruit juice samples ranged from 82.7%to 98.6%,with intra-day and inter-day relative standard deviations(RSD)of 1.2%-6.1%and 1.3%-9.0%,respectively.The enhancement factors ranged from 43.4 to 48.1 for all the analytes when 10 mL juice sample was used as loading solution.The reusability of the fabricated ZIF-8@Fe3O4 adsorbent was investigated,and the RSD for recoveries of benzoylurea insecticides for 10 consecutive adsorption-desorption cycles in sample solutions were not more than 8.8%.The proposed method is sensitive and effective,and could be applied in the determination of benzoylurea insecticides in fruit juice samples.