Fe_(3)O_(4)@MOF-808磁性固相萃取结合高效液相色谱法测定大米中3种二苯醚类除草剂  

Determination of three diphenyl ether herbicides in rice by magnetic solid phase extraction using Fe_(3)O_(4)@MOF-808 coupled with high performance liquid chromatography

作　　者：闫萌 贾叶青 齐沛茹 王雅慧 冀欠欠 王曼曼 王茜 郝玉兰 YAN Meng;JIA Yeqing;QI Peiru;WANG Yahui;JI Qianqian;WANG Manman;WANG Qian;HAO Yulan(School of Public Health,North China University of Science and Technology,Tangshan 063210,China)

机构地区：[1]华北理工大学公共卫生学院,河北唐山063210

出　　处：《色谱》2021年第3期316-323,共8页Chinese Journal of Chromatography

基　　金：河北省自然科学基金项目(H2017209232);河北省教育厅重点项目(ZD2018014).

摘　　要：利用溶剂热法构筑了Fe_(3)O_(4)@MOF-808吸附剂,将其用于大米中除草醚(NIT)、乙氧氟草醚(OXY)和甲羧除草醚(BIF)3种二苯醚类除草剂的富集,结合高效液相色谱法,建立了大米中该类除草剂的分析方法。研究通过傅里叶变换红外光谱、X射线衍射仪、扫描电子显微镜以及振动样品磁强计对构筑的磁性吸附剂的结构、表面形貌及磁强度进行表征。表征结果显示,球形的Fe_(3)O_(4)纳米颗粒与八面体形貌的MOF-808成功复合,Fe_(3)O_(4)@MOF-808饱和磁化强度可达40.35 emu/g,可以满足磁性固相萃取的需求;对吸附剂用于大米中3种二苯醚类除草剂富集的磁性固相萃取条件(吸附剂用量、吸附时间、洗脱溶剂种类以及洗脱体积)进行了优化。优化结果显示,25 mg吸附剂在6 min内即可达到对目标物的完全吸附,洗脱溶剂采用0.5 mL×2的甲醇。在最优的磁性固相萃取条件下,结合高效液相色谱-紫外检测法,建立了大米中3种二苯醚类除草剂的分析方法。方法在2~300μg/L范围内线性关系良好(r>0.998),NIT、OXY、BIF的检出限和定量限依次为0.6、0.6、0.4μg/kg和2.0、2.0、1.5μg/kg,在5、10和20μg/kg 3个加标水平下的回收率为87.3%~96.7%,相对标准偏差不超过10.8%,且富集因子在25~29之间。将所建方法用于大米中NIT、OXY、BIF的分析,各样品均未检出这3种二苯醚类除草剂。该方法具有操作简单、快速、准确的特点,适用于大米样品中除草剂的残留分析。The complex matrix of rice samples and the small amount of the target analytes in the sample necessitate an effective pretreatment process to enrich the target analytes and minimize matrix interference before instrumental analysis.Magnetic solid phase extraction(MSPE)is a dispersive solid phase extraction technique which allows for the rapid separation of sorbents from the sample solution under an external magnetic field.Compared with other traditional solid phase extraction methods,MSPE has the advantages of convenient operation,minimal interference and absence of column pressure.In this work,a metal organic framework composite(Fe_(3)O_(4)@MOF-808)was synthesized by a facile solvothermal method for using as an effective adsorbent to concentrate nitrofen(NIT),oxyfluorfen(OXY)and bifenox(BIF)in rice samples.Based on the pretreatment,a method was developed by coupling with high performance liquid chromatography-ultraviolet detection(HPLC-UV).The prepared material was characterized by Fourier-transform infrared spectroscopy,X-ray diffractometry,scanning electron microscopy and vibrating sample magnetometry measurements for determining its functional groups,morphology and magnetic strength.The results showed that MOF-808 has a regular octahedral morphology and well-dispersed,and the particle size of the material ranged from 400 to 500 nm with a smooth surface.The spherical Fe_(3)O_(4)particles were uniformly attached to the surface of the octahedral MOF-808 crystals.The maximum saturation magnetization of this composite was 40.35 emu/g which is lower than the saturation magnetization Fe_(3)O_(4)(78.26 emu/g)but still sufficient for the requirements of MSPE.The prepared Fe_(3)O_(4)@MOF-808 was used in the MSPE of three diphenyl ether herbicides(Des)in rice.As is well known,the key factors influencing MSPE are the adsorption and elution processes.In order to establish the optimal extraction conditions,the adsorption parameters(adsorbent amount,extraction time,elution solvent and elution volume)were investigated in deta

关 键 词：磁性固相萃取 高效液相色谱 二苯醚类除草剂 大米 金属有机骨架 

分 类 号：O658[理学—分析化学]