基于新型固定化金属亲和材料的有机磷农药多残留CE分析方法的研究

A large amount of organophosphorus pesticides (OPPs) are widely used in agriculture around the word in the past few decades. Concerning the toxic effects, the presence of pesticide residues in the environment and food will be a threat for humans. The food safety problem has restricted the export competitiveness of agricultural products in China. Therefore, there is a great demand to develop powerful sample preparation techniques as well as multi-residue analytical methods for OPPs analysis. In this project, on the basis of the selective extraction of OPPs, metal ions and metal oxide, such as Al(III), Fe(III), Zn(II), Cu(III), Ti(IV), functionalized nanomaterials were prepared and employed as adsorbents to develop sample preparation techniques. In addition, the novel metal-organic frameworks (MOFs) materials with Al(III), Fe(III), Zn(II), Cu(III) as the metal center, were used to fabricate open tubular (OT) capillary column. Combining with online enrichment techniques, a capillary electrochromatography (CEC) method was established to effectively separate and sensitively detect various OPPs. Furthermore, the new sample preparation techniques and online concentration–CEC separation methods were united to fabricate a new multi-residues analytical platform. It can not only adapt CE well to the requirement of food safety analysis and environmental analysis, but also play a significant role on the improvement of detection level of OPPs in our country.

由于长期、广泛及违规使用，大量有机磷农药残留于食品、环境当中，造成食品和环境污染，威胁国民身体健康。发展针对食品、环境或血液等复杂基质中残留有机磷农药的多残留分析技术十分重要。基于Al(III)、Fe(III)、Zn(II)、Cu(III)等金属离子/氧化物与有机磷农药的特异性亲和作用，本项目拟将该类金属离子/氧化物固定于氧化石墨烯、碳纳米管等纳米载体上，制备固定化金属复合纳米材料进行固相萃取，发展有效的样品前处理方法。将该类金属为位点中心的金属-有机骨架(MOFs)材料涂层至毛细管壁，制备固定化金属修饰开管柱，建立分离能力更好、灵敏度更高的在线富集-毛细管电色谱(CEC)分离新方法。样品前处理及CEC分离两种方法协同使用，构建有机磷农药多残留分析方法。本项目的研究，不仅使毛细管电泳能够满足食品安全分析和环境分析方面的要求，而且将为我国有机磷农药多残留分析提供科学依据和技术支持。

本项目中，以Fe3O4和GO@Fe3O4为纳米载体，以多巴胺为桥连分子，以Ti(IV)和Zr(IV)为识别探针，设计合成了Fe3O4@PDA-Ti4+、Fe3O4@PDA-Zr4+和GO@Fe3O4@PDA-Ti4+三种固定化金属亲和材料并表征。考察发现这种材料对草甘膦、草铵膦和氨甲基膦酸等有机磷类农药具有很好的选择性识别能力。以Fe3O4@PDA-Ti4+ NPs为固相萃取剂建立了磁性固相萃取样品前处理方法，通过乙腈-盐堆积大体积进样毛细管电泳，建立了mSPE-CE新方法，可用于实际样品的测定。此外，制备了以手性β-环糊精修饰的周期性介孔氧化硅材料涂层毛细管开管柱并表征。考察优化了缓冲体系，采用毛细管电色谱（CEC）实现了DL-Leu和DL-Pro的手性拆分。为解决坚果等高脂肪类食品中农药残留的样品前处理难题，发展了改良的QuEChERS样品前处理方法，用于提取和净化，并采用液质联用技术检测了坚果中的38种农药残留。本项目的开展和研究扩宽了纳米材料在农药残留样品前处理中的应用，提高了毛细管电泳对农药残留的分离和检测能力，对食品安全检测研究具有重要意义。