基于表面分子印迹电化学技术的植物油3-氯-1,2-丙二醇检测方法研究

Chloropropanol, as a harmful product in the process of food processing, widely exists in vegetable oil and other foods. In reality, 3-monochloropropane-1, 2-diol (3-MCPD) used as an indicator to reflect the situations of production of chloropropanols in food processing. The current molecularly imprinted electrochemical method for the detection of 3-MCPD cannot be used directly for detecting vegetable oils and requires preprocessing. In order to simplify the sample preparation process and increase the recognition rate of 3-MCPD when using modified electrode in organic phase electrolyte, firstly, a modified electrode from a carbon nanotube/silica molecularly imprinted polymer was prepared by self-assembly technique. Furthermore, based on multivariable combination method, an organic phase electrolyte which is suitable for the reaction of modified electrode was constructed. Then, taking advantage of Surface Enhanced Raman Spectra and other structure analysis techniques with rotating disk electrodes and other isoelectric analysis techniques, and studying the interface properties of ‘electrode/solution’, mass transfer process in interface microenvironment, and the electrode reaction process when using modified electrode to recognize 3-MCPD, completely explain the essential reason why the reaction rate of the modified electrode was significantly slower than aqueous electrolyte. Therefore, through this novel method of high sensitivity about molecular imprinted electrochemical detection for 3-MCPD in vegetable oil, it would provide a theoretical basis for promoting the surface molecular imprinting electrochemical sensing technology applied to fat-soluble substances trace detection.

氯丙醇是食品加工过程中的有害产物，广泛存在于植物油等食品。现实中常以3-氯-1,2-丙二醇（3-MCPD）为指标反映食品加工过程中氯丙醇类物质的生成情况。目前检测3-MCPD的分子印迹电化学方法不能直接用于植物油检测，需要前处理。为了在简化样品前处理步骤的同时，提高有机相电解液中修饰电极对3-MCPD的识别率，本研究拟采用自由基聚合法制备碳纳米管/二氧化硅表面分子印迹聚合物修饰电极；采用多变量组合法，构建适于修饰电极反应的有机相电解液；通过运用表面增强拉曼光谱等结构解析技术与旋转圆盘电极等电分析技术，研究“电极/溶液”界面性质、界面微环境中传质过程及修饰电极识别3-MCPD的电极反应历程，探讨有机相下修饰电极的电极过程反应动力学；通过建立高灵敏度植物油3-MCPD检测的新方法，为推动表面分子印迹-电化学传感技术在脂溶性物质痕量检测中的应用提供理论依据。

氯丙醇是食品加工过程中的有害产物，广泛存在于植物油等食品。目前检测氯丙醇的分子印迹电化学方法不能直接用于植物油检测，需要前处理。为了简化样品前处理步骤，提高有机相中修饰电极对氯丙醇的识别率，本项目拟制备表面分子印迹聚合物修饰电极，构建适于修饰电极反应的有机相电解液，建立高灵敏度植物油3-MCPD检测的新方法，为推动表面分子印迹-电化学传感技术在脂溶性物质痕量检测中的应用提供理论依据。研究成果如下：.（1）本研究以金纳米粒子作为传感器的增敏材料，以3-MCPD 为模板分子，对巯基苯胺为功能单体，制备分子印迹膜电化学传感器，确定了分子印迹聚合物及其修饰电极最优制备工艺；（2）采用多变量组合法，构建了适于植物油中3-MCPD 检测以及修饰电极反应的有机相电解液；（3）阐明了有机相下修饰电极过程动力学；（4）通过标准加入法建立了高灵敏度植物油3-MCPD检测的新方法，对植物油样品中的3-MCPD含量进行加标回收率测定，结果显示，该方法的添加回收率为96.44%-104.35%之间，相对标准偏差RSD低于3.37%，证明新方法回收率较好，结检测结果较稳定，适用于对实际植物油样品中的3-MCPD检测分析。（5）在国内外重要学术期刊上发表研究论文3 篇，授权发明专利4项，申请发明专利1 项，培养研究生 1 名。.本项目的开展，解决了现有检测技术与方法无法满足油脂中氯丙醇类物质快速检测需要的问题，有助于为食品安全监管部门提供一线执法的必要检测工具，强化食品安全技术保障手段。