电解离子水消除果蔬典型有机磷农药残留的作用机制及反应调控

Pesticides residues of fruits and vegetables is a research focus in the field of food safety. Based on the objective analysis on the properties of electrolyzed water and organophosphorus pesticides (OPs) as well as the scientific problems which reflected their mutual infulencing mechanism, three key issues are put out in the present study. The changes of physicochemical parameters of electrolyzed water during prepartion would be clarified by evaluting the macro and micro properties of electrolyzed water by electrochemistry point of view. The influencing factors of electrolyzed water on OPs would be evaluted based on the several typical OPs in the water solution system. The degration mechanism of electrolyzed water against OPs would be studied in different conditions and medium and the degradadation path also clarified by the modern chemical analisis methods. Also, taking the model of OPs-polluted fruits and vegetables as the research object, the washing dissociating mechanism and degradation mechanism of electrolyzed water in the treatment of fruits and vegetables in practice would be discussed in this project. Moreover, the processing using electrolyzed water to eliminate the OPs residues in fruits and vegetables would be optimized and the effective adjustment methods on degradation substance and objective substance by the changes of conditon factors and media factors would be established. The objective of the present project is to establish an effective, enviroment-friendly and affordable technique to eliminate the OPs in fruits and vegetables, and to provide the theoretic and technical supports for solving the problem of OPs residues in frut and vegetables whithin electrolyzed water.

果蔬的农药残留问题是食品安全领域的研究热点。本项目在客观分析电解离子水及果蔬有机磷农药自身性能特性及二者作用机制所蕴藏的科学问题基础上，凝练出三个关键性问题开展研究。通过从电化学角度研究电解离子水的宏观和微观性能，阐明电解离子水性能指标的生成变化规律，以几种典型有机磷农药水溶液体系为基础，明确电解离子水降解有机磷农药残留的影响因子；结合现代化学结构分析手段，掌握不同介质环境和条件因子下电解离子水对对有机磷农药降解的影响机制，阐明其降解途径，并以果蔬污染模型为对象，探讨电解离子水实际处理果蔬的洗脱解离机制和降解机制，探索电解离子水消除果蔬有机磷农药残留的强化工艺条件，明确条件因子与介质环境选择性定向转化目标产物的有效调控方法。本项目的实施目的在于建立一种高效、环保、低成本的果蔬有机磷农药残留消除技术，为利用电解离子水解决果蔬有机磷农药残留问题的实际应用提供理论和技术支持。

有机磷农药残留问题已引起国内外科学家的广泛关注，现有的农药残留降解技术手段均存在弊端且影响技术的推广。本研究以常用的典型有机磷农药（乐果、敌敌畏、毒死蜱、对硫磷和甲基对硫磷）和农药残留检出率较高的韭菜为研究对象，探讨了电解离子水消除果蔬有机磷农药残留的作用机制，主要研究结果如下：. 利用实验室自制的无隔膜型电解离子水发生器，对不同操作条件（盐酸浓度、氯化钠浓度、电解电压、电解电流、电解时间和电极板距离）下电解离子水的pH和有效氯浓度进行了研究，阐明了制备电解离子水的一般规律。. 通过对不同电解离子水在贮藏过程中、以及相同理化指标的次氯酸钠溶液产生羟自由基能力的研究，发现在不同pH值和有效氯浓度范围内，电解离子水产生羟自由基能力均要比同指标的次氯酸钠溶液强；有效氯浓度和pH值变化对电解离子水产生羟自由基能力产生综合影响；微酸电解离子水产生羟自由基的能力在贮藏时间为5h时达到最大。. 以毒死蜱、对硫磷、甲基对硫磷和乐果标准品水溶液体系为研究对象，分别研究了不同单一组分对电解离子水的敏感性及其降解产物。结果表明：有效氯浓度大于.5 mg/L时，反应时间30 s内，对硫磷、乐果、毒死蜱、和甲基对硫磷的降解率分别达到100%、100%、99.96%、99.86%。采用气相色谱-质谱联用(GC-MS)检测到毒死蜱、对硫磷和甲基对硫磷的直接降解产物，并分析了电解离子水对四种典型有机磷农药的降解途径。. 电解离子水能有效去除韭菜中敌敌畏、乐果和毒死蜱残留，降解率分别达到了98.79%、51.70%和72.55%，比同浓度的NaClO溶液降解效果好；有效氯浓度的升高能增强酸性电解离子水对三种农药残留的去除效果。在20-50℃范围内时，电解离子水的温度对农药残留的去除效果影响不大；原料与电解离子水比为15:500(g:mL)为最佳工艺条件。贮藏不同时间后的电解离子水对乐果和毒死蜱残留的去除效果差异说明电解离子水对有机磷农药的去除率与其产生羟自由基能力有相关性。