Laboratory of Bioseparation and Analytical Biochemistry, State Key Laboratory of Microbial Metabolism, School of Life Science and Biotechnology, Shanghai Jiao Tong University, Shanghai 200240, China.
Analyst. 2013 Sep 7;138(17):5039-51. doi: 10.1039/c3an00643c. Epub 2013 Jun 28.
In this paper, a general mode and theory of moving chelation boundary based isotachophoresis (MCB-based ITP), together with the concept of decisive metal ion (DMI) having the maximum complexation constant (lg Kmax) with the chelator, were developed from a multi-MCB (mMCB) system. The theoretical deductions were: (i) the reaction boundary velocities in the mMCB system at steady state were equal to each other, resulting in a novel MCB-based ITP separation of metal ions; (ii) the boundary directions and velocities in the system were controlled by the fluxes of chelator and DMI, rather than other metal ions; and (iii) a controllable stacking of metal ions could be simultaneously achieved in the developed system. To demonstrate the deductions, a series of experiments were conducted by using model chelator of EDTA and metal ions of Cu(II) and Co(II) due to characteristic colors of blue Cu-EDTA and pink Co-EDTA complexes. The experiments demonstrated the correctness of theoretical deductions, indicating the validity of the developed model and theory of ITP. These findings provide guidance for the development of MRB-based ITP separation and stacking of metal ions in biological sample matrix and heavy metal ions in environmental samples.
本文从多移动螯合边界（mMCB）系统出发，提出了一种通用的基于移动螯合边界的等速电泳（MCB 基 ITP）模式和理论，以及具有最大螯合常数（lg Kmax）的决定金属离子（DMI）的概念。理论推导为：（i）mMCB 系统在稳态下的反应边界速度彼此相等，从而实现了新型的 MCB 基 ITP 金属离子分离；（ii）体系中边界的方向和速度由螯合剂和 DMI 的通量控制，而不是其他金属离子；（iii）在开发的体系中可以同时实现金属离子的可控堆积。为了验证这些推论，本文使用 EDTA 模型螯合剂和 Cu(II)和 Co(II)金属离子进行了一系列实验，这是由于蓝色 Cu-EDTA和粉红色 Co-EDTA配合物的特征颜色。实验证明了理论推导的正确性，表明了所开发的 ITP 模型和理论的有效性。这些发现为基于 MCB 的 ITP 分离以及生物样品基质中金属离子和环境样品中重金属离子的堆积提供了指导。
