Flow Injection Analysis on Extraction of Trace Metal Ions with Mixed Solvents

本研究旨在为溶剂萃取流动注射分析新技术的发展提供基础和重要的信息。我们掌握了以下信息。对非卤代混合溶剂萃取络合物(萃取性、相分离能力)的评价考虑了金属络合物的灵敏度、稳定性和萃取络合物的选择性，选择了吡啶偶氮-磺酸体系。除了基于分配平衡的选择性外，阴离子金属络合物在水相中的生成反应提高了金属离子的萃取选择性。到目前为止，离子缔合萃取只使用氯仿等卤化溶剂。从环保的角度来看，这些溶剂不适合使用。应尽可能控制这些溶剂的使用。然后，一些替代的…用铜(II)-PAN-S体系考察了更多的S对这些溶剂的影响，发现1-辛醇/辛烷混合溶剂具有良好的萃取性和相分离能力。此外，还阐明了离子缔合物的分配可以通过改变溶剂的混合比例来控制。络合剂对金属离子选择性萃取的评价(高效液相色谱法)通过对铜(II)-PAN-S体系萃取平衡的详细分析，估算了迄今鲜有报道的离子缔合物在水相中的形成常数及其分配常数。从离子缔合物在液-液分配中的分配常数与离子缔合物在高效液相中的容量因子之间的相关性的角度对各络合剂进行了评价。在铁、钴、镍、铜与几种吡啶偶氮类化合物的离子缔合物向反相固定相的分配中，PAN-S体系中的铜、钴络合物即使在反离子存在下也很难被保留，而且这些离子对的分配明显低于铁和镍的络合物。这些试剂与上述混合溶剂的组合有望开发出适用于金属络合物萃取的流动注射分析系统。较少

The present research was carried out in order to obtained the fundamental and important informations for the development of new flow injection analysis on solvent extraction. We had the following informations.1. Evaluation of a non-halogenated mixed solvent in the extraction of a complex(extractability, phase-separating ability)Taking account of the sensitivity and stability of metal complex and the selectivity in the extraction of the complex, pyridylazonaphthol-sulfonic acid system was selected. In addition to the selectivity on the basis of the partition equilibrium, the formation reaction of anionic metal complex in the aqueous phase enhances the selectivity of the extraction of metal ions. Up to this time, halogenated solvents such as chloroform have been exclusively used for ion association extraction. From the point of view of the ecopolicy, these solvents are undesirable for use. These solvents should be controlled regarding their use as much as possible. Then, some alternative … More s to these solvents were examined with copper (II) -PAN-S system, and it was found that 1-ocatnol/octane mixed solvent could be expected to have good extractability and good phase-separating ability. In addition, it was clarified that the partition of ion associate could be controlled by changing the mixing ratio of these solvents.2. Evaluation of complexing agent on the selective extraction of metal ions (use of HPLC)The formation constants of ion associates in the aqueous phase and their partition constants, which were scarcely determined so far, could be estimated by an detailed analysis of extraction equilibrium for the copper (II)-PAN-S system. The assessment of each complexing agent was achieved on HPLC systems from the point of the correlation between the partition constants of ion associates in the liquid-liquid partition and their capacity factors in HPLC.In the partition of ion associates for iron, cobalt, nickel, and copper complexes with a few kinds of pyridylazo compounds to the reversed-phase stationary phase, copper and cobalt complexes in the PAN-S systems were hardly retained even under the presence of a counter ion, and the partition of these ion pair was found to be markedly lower than that of iron and nickel complexes. The useful flow injection analysis syatem on the extraction of a metal complex is expected to be developed by a combination of these reagents and the mixed solvents described above. Less