四氧化三铁负载石墨化碳黑磁性纳米材料的制备及其在茶叶中多种农药残留检测中的应用

Preparation of Ferroferric Oxide Loaded Graphitized Carbon Black Magnetic Nanomaterials and Application in Detection of Pesticide Residues in Tea

基于物理共混法制备了一种均匀的四氧化三铁负载石墨化碳黑磁性纳米材料(GCB/Fe_(3)O_(4))。以此为固相萃取吸附剂,建立了酚钙共沉淀-磁性固相萃取-气相色谱/三重四极杆串联质谱技术(GC-MS/MS)同时测定茶叶中405种农药残留的分析方法。对GCB/Fe_(3)O_(4)的晶体结构、表面形貌以及吸附色素的能力进行了探讨。结果表明,所制备的材料均匀,对儿茶素、姜黄素及叶绿素铜钠的饱和吸附量分别为8.89、9.38和3.68 mg/g。与GCB相比,提高了姜黄素和叶绿素铜钠5%~87%的吸附量,且能够吸附GCB所无法吸附的儿茶素。采用该材料对茶叶中405种农药残留检测进行净化前处理,平均回收率为48.2%~123.6%,相对标准偏差为0.4%~14.5%,其中377种农药的回收率在70%~120%,占比93.1%。结果表明,该材料具有良好的净化效果,适用于多种农药回收率的检测,有较高的应用推广价值。

A homogeneous ferroferric oxide loaded graphitized carbon black(GCB)magnetic nanomaterials was prepared based on a physical blending method.A method for the simultaneous determination of 405 pesticide residues in tea was established by using GCB/Fe_(3)O_(4)as a solid-phase extraction(SPE)adsorbent and using phenol-calcium coprecipitation,magnetic SPE,and gas chromatography/triple quadrupole tandem mass spectrometry(GC-MS/MS).The crystal structure,surface morphology and adsorptive capacity of GCB/Fe_(3)O_(4)were studied.The results show that the prepared materials are uniform,and the saturated adsorption capacities of catechin,curcumin and copper sodium chlorophyllin are 8.89 mg/g,9.38 mg/g,and 3.68 mg/g,respectively.Compared with GCB,the adsorption capacity of curcumin and copper sodium chlorophyllin is increased by 5%~87%,and catechins in tea that cannot be adsorbed by GCB are also absorbed.The material is used to detect 405 pesticide residues in tea,the average recovery rate is 48.2%~123.6%,and the relative standard deviation is 0.4%~14.5%.Among them,the recovery rate of 377 pesticides is 70%~120%,accounting for 93.1%.The results show that the material has a good purification effect and is suitable for the detection of recovery rate of many kinds of pesticides.