Standardization for trace metal ion speciation by the electrochemical

为了建立痕量金属离子形态的标准化方法，收集了金属离子（铜和镍）与腐殖酸（HA）和腐殖酸（FA）相互作用的络合容量（CC）和条件稳定常数（K’）等基本数据。HA和FA由日本腐殖质学会配制为标准材料。用吸附溶出伏安法测定金属离子滴定的CC和K′。以喹啉-8-醇（OX）和二甲基乙氧肟（DMG）分别作为铜和镍的络合配体。随着OX和DMG浓度的增加，HA和FA的CuCC和NiCC降低，K值升高。这表明，由于HA和FA是具有各种官能团和大分子量的有机化合物的混合物，因此存在着不同配位能力的各种配位位点。CuCC（HA）、NiCC（HA）、CuCC（FA）和NiCC（FA）的相对值分别约为450、30、30…More和1。为了解释这些基于化学平衡的结果，假设三个配位基团具有不同数量的位点（即CC）和K'。然后，在假设一个金属离子与一个配位位反应的前提下，采用计算CC和K′的常规方法，对模拟的金属离子滴定曲线进行了分析。对假设配位点的不同初始CC和K′进行重复计算，直到计算出的CC和K′在观测值范围内。对于Cu-HA、Ni-HA、Cu-FA的相互作用，观测值与计算值吻合较好。这使我们能够讨论HA和FA的协调点分布。此外，还开展了物种形成概念的普及、高输出低压汞灯紫外无公害前处理水样、利用催化效应进行电化学超痕量分析、合成多齿配体表征镧系离子及其在溶剂萃取中的应用、制备大轮混价化合物表征大分子等项目。这些项目也获得了新的结果。少

To establish the procedure of the standardization for trace metal ion speciation, fundamental data, such as complexing capacity(CC) and the conditional stability constants(K'), for the interaction of metal ion (copper and nickel) and humas(humic(HA) and fulvic acids(FA)) were collected. HA and FA were prepared as standard materials by The Japan Society for Humic Substances. CC and K' were estimated from metal ion titration by adsorptive stripping voltammetry. Quinoline-8-ol(OX) and dimethylglyoxime(DMG) were used as complexing ligands for copper and nickel, respectively. As the increase of the concentration of OX and DMG, CuCC and NiCC for HA and FA were decreased while K's were increased. This indicates the presence of various coordination sites having different coordination ability, because HA and FA are the mixture of organic compounds having various functional groups and large molecular weights. The relative values for CuCC(HA), NiCC(HA), CuCC(FA) and NiCC(FA) were ca. 450, 30, 30 … More and 1, respectively. To explain these results based on chemical equilibria, three coordination groups, having different number of sites(that is,CC) and K', were assumed. And then, the simulated metal ion titration curve were analyzed by the normal procedure for obtaining CC and K' based on the assumption that one metal ion reacts with one coordination site. This calculation was repeated for different initial CC and K' for assumed coordination sites till the calculated CC and K' were within the range of observed values. For the interactions of Cu-HA, Ni-HA, Cu-FA, good agreement was obtained between observed and calculated values. This enabled us to discuss about the distribution of coordination sites in HA and FA. Additional projects for speciation were also carried out on popularization of the concept of speciation, contamination-free pre-treatment of water samples by UV irradiation with high output low-pressure mercury lamp, electrochemical ultra trace analysis using catalytic effect, synthesis of multidentate ligands to specaiate lanthanide ions and their application to solvent extraction, and production of big wheel mixed-valence compounds to speciate giant molecules. Novel results were also obtained for these projects. Less