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化学修饰电极表面的表征是修饰电极研究的重要方面,我们曾报道用三辛基氧化膦(TOPO)修饰电极进行铕(Ⅲ)的测定,发现在含有Eu~(3+)和噻吩甲酰三氟丙酮(HTTA)的HAc-NaAc溶液中,能得到一个十分灵敏的阴极溶出峰,而HTTA不存在时,则无明显的峰因此,HTTA对Eu~(3+)的富集过程一定起着某种重要的协同作用,我们认为,HTTA在溶液中存在酮式与烯醇式的平衡,其烯醇式与溶液中的Eu~(3+)和H_2O形成中性络合物[Eu(TTA)_3·(H_2O)],当其扩散至TOPO修饰电极表面时,电极表面的TOPO就将其水分子取代,生成更稳定的协同三元络合物,从而将Eu~(3+)富集在电极表面:
The characterization of the chemically modified electrode surface is an important aspect in the study of the modified electrode. We reported that the determination of europium (Ⅲ) with trioctylphosphine oxide (TOPO) modified electrode showed that in the presence of Eu 3+ and theno- In HAc-NaAc solution of HTTA, a very sensitive cathodic dissolution peak was obtained, but no significant peak was observed in the absence of HTTA. Therefore, the HTTA enrichment process of Eu ~ (3+) Some important synergistic effect, we believe that there is a keto-enol equilibrium in HTTA solution. The enol forms a neutral complex with Eu ~ (3+) and H_2O in the solution [Eu (TTA ) _3 · (H_2O)]. When it diffused to the surface of TOPO modified electrode, the TOPO on the electrode surface replaced its water molecules to form a more stable synergistic ternary complex, thus enriching Eu ~ (3+) On the electrode surface: