水胺硫磷分子印迹固相微萃取涂层的制备及在果蔬水胺硫磷农药检测中的应用

Preparation and application of molecularly imprinted solid-phase microextraction coating for determination of isocarbophos in fruits and vegetables

以聚乙二醇为功能单体,水胺硫磷为模板分子,采用溶胶-凝胶技术,制备水胺硫磷分子印迹固相微萃取涂层,并建立顶空固相微萃取与气相色谱(HS-SPME/GC)联用检测果蔬中水胺硫磷残留量的方法。结果表明,制备的印迹涂层对水胺硫磷具有较高的选择性,且萃取能力大大高于非印迹涂层及常用商用涂层。在最优条件下,建立的检测方法在10～10 000μg/kg范围内线性相关系数为0.999 6,检出限为5.6μg/kg,5次重复实验所得相对标准偏差为2.29%。应用该检测方法测定黄瓜、蕃茄、苹果、梨和大白菜等5种果蔬基质中水胺硫磷含量时,均未有水胺硫磷检出,在5种基质中加标回收率均在89.4%～106.6%之间。

An isocarbophos molecularly imprinted solid-phase microextraction(MISPME)coating was prepared by sol-gel technology with polyethylene glycol as a monomer and isocarbophos as a template,and a headspace solid phase microextraction method coupled with gas chromatography(HS-SPME/GC)for the determination of isocarbophos in fruits and vegetables was established.Results showed that the imprinted coating had very good selectivity to isocarbophos,and its extraction capability was better than the non-imprinted fiber and commercial fibers.At the optimum conditions,the proposed method was linear in the range of 10-10 000μg/kg with a coefficient of 0.999 6.The limit of detection was 5.6μg/kg.The relative standard deviation of 5 replicates was 2.29%.The method was used for the determination of isocarbophos in 5 kinds of real samples including cucumber,tomato,apple,pear and cabbage.The results indicated that no residue of isocarbophos was detected in these samples.Satisfactory recoveries of 89.4%-106.6%were obtained in these matrices,indicating the accuracy of the method.