基于磁性介孔碳的新型萃取技术在汞形态分析中的应用研究

The mercury speciation analysis in environmental samples is one of very important research area in analytical science. The preliminary separation/preconcentration of target analytes prior to their determination is usually required in real samples analysis due to their low concentrations and matrix effects. In view of many advantages of magnetic solid phase extraction (MSPE) showing in the field of sample preparation, and the excellent adsorption performance of magnetic mesoporous carbon, therefore, in this project, we intend to synthesis carbon-coated magnetic nanoparticles (C-MNP) and sulfur-doped magnetic mesoporous carbon (S-MMC) and to use them as magnetic solid phase adsorption materials for mercury speciation. The factors influencing extraction efficiency will be studied and analytical performance of MSPE-HG-AFS/HPLC-HG-AFS for mercury speciation analysis will be evaluated completely. Magnetic solid phase extraction methods based on C-MNP and S-MMC will be developed for the speciation of mercury prior to their measurements by HG-AFS and HPLC-HG-AFS and will be applied to determine the speciation of mercury in farmland soil and irrigating water samples. The described techniques possess high speed, cheapness, simplicity and high performance and the project will help us to find out the precise level of different speciation of mercury in environment samples. Moreover, these methods can provide important academic foundation for effective evaluating the toxicity, beneficial effects, and the metabolism in the organism of the different species of mercury, so, there are significant academic value and extensive application future with this project.

环境样品中的汞形态分析是分析科学非常重要的研究方向之一，然而此类样品中汞含量极低且基体复杂，往往需要在测定之前辅以适当的预分离/富集手段。磁固相萃取(MSPE)在样品前处理领域已展示出诸多优势，基于磁性介孔碳的优异吸附性能，兼顾MSPE简便、快捷的特点，本项目拟制备碳包磁性铁氧化物和硫掺杂磁性介孔碳材料，并以此为汞形态分析中MSPE的吸附材料，研究影响MSPE的诸因素，全面评价MSPE-HG-AFS/HPLC-HG-AFS用于汞形态分析的分析性能；构建MSPE-HG-AFS/HPLC-HG-AFS分析汞形态的新方法，并应用于农田土壤和农业灌溉用水中汞形态分析。本项目所建立的形态分析方法快捷、简便、高效，能使人们更全面、更深入地了解自然环境中各种汞形态的含量水平，为有效评价汞各形态的毒性、有益作用及其在生物体内的代谢行为提供重要的理论依据，因此该课题具有重要学术价值和应用前景。

面对日益严峻的环境水体污染问题，如何快速、高选择性、高效地去除环境水体中的染料污染物是环境分析化学家所面临的一个重大挑战。基于磁性介孔碳兼具可磁性分离、分析速度快以及碳基质材料比表面积大、吸附容量高的优点，本项目研制了几种不同碳源、不同碳源含量以及不同铁源含量的磁性介孔碳材料，研究了上述材料对甲基橙和刚果红的吸附行为、脱附行为、重复利用性及热、动力学行为。研究结果表明碳源中碳的数目和含量越高，其对污染物的吸附容量越大，用糠醇充当碳源的磁性介孔碳材料对甲基橙的饱和吸附容量为101 mg g-1，用酚醛树脂充当碳源的磁性介孔碳材料对甲基橙的饱和吸附容量为120 mg g-1，用壳聚糖充当碳源的磁性介孔碳材料对甲基橙的饱和吸附容量可高达400 mg g-1；对于同一碳源而言，如壳聚糖，当碳源壳聚糖掺入量从0.1 g增至0.25和0.5 g时，其对目标染料甲基橙的饱和吸附容量则从139 mg g-1分别增至208和400 mg g-1；当铁源掺入量增加时，材料的磁性能也明显加强，可缩短磁分离的时间，说明项目组已成功制备了高效的磁性介孔碳复合功能材料。本项目所建立的快捷、简便和高效的染料污染物去除方法不仅可以为染料污染物的去除提供有益的理论依据，开发经济高效的染料污染物吸附剂，还可探索材料结构与其吸附性能之间的构效关系，为新型吸附剂设计提供理论依据，为环境保护与资源再利用提供技术支撑。