分散液液微萃取（DLLME）以其简单快速、富集倍数高、微量化等优势，在痕量物质分离富集方面具有很高的应用价值。其中，在线化DLLME不仅能降低误差，提高样品吞吐量，还因整个过程处于相对封闭环境，既能降低目标物的损失和玷污，又能减少二次污染，是该领域的研究前沿。但是，在线DLLME中相分离过程费时低效以及微量萃取相移取过程中易损失的问题已严重限制其发展。为此，本项目面向汞形态分析，将对折流-柱阵扩缩协同相分离理论和方法进行全面深入研究：1）从理论出发，阐明微滴形成和分散机理，揭示汞形态传质动力学过程及其影响规律，为萃取和相分离提供理论基础；2）揭示微滴分级聚合效率-折流几何结构-微滴分布之间的关系，阐明液滴扩缩合并机制及其在柱阵中的行为规律，并设计构建折流-柱阵扩缩相分离系统，实现微量萃取相的快速分离和精准收集；3）阐明在线萃取及其相分离系统和汞形态分析的构效关系，并以此建立其在线分析方法。

Dispersive liquid-liquid microextraction (DLLME) represents an important development in the field of sample pretreatment for its simplicity, miniaturization and rapidity, and could achieve of high enrichment factor, thus being regarded as a valuable technique in separation and enrichment of trace analytes. One of the most interesting aspects of DLLME is its capacity for the online processing, which offers several advantages, such as minimizing the errors associated with manual handling, increasing sample throughput and reducing loss and contamination of analytes as well as the secondary pollution, resulting in improving the sensitivity and precision of the method. However, time consuming and inefficient phase separation and the loss of microvolume of extractant in the subsequent phase transfer in online DLLME became common problems of the existing methods that deeply restrict their further development. To this end, faced on the application of mercury speciation analysis, a deep study focus on the theories and methods of zigzag-pillar synergistic induced phase separation will be carried out: 1) Started from the basic theories, mechanism of formation and dispersion of microdroplet in online DLLME, and also the mass transfer kinetic process of mercury species as well as its influence law will be studied, providing theoretical basis for the extraction and phase separation studies. 2) The relationship of the graded polymerization efficiency of microdroplet, geometric structure of zigzag manifold and the distribution of microdroplet in DLLME will be discussed, and the mechanism of droplet merging as well as its behavior in pillar chamber will be studied. A zigzag-pillar synergistic induced phase separation system is to be designed and built, realizing a rapid separation and accurate collection of microvolume of extractant. 3) Reveal the structure-activity relationship between online DLLME with its phase separation system and mercury speciation analysis, based on which an online analytical method for mercury species will finally be established.