摘要
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 preconcentration and stripping processes of cathodic stripping voltammetric determination of Eu(Ⅲ) by using tri-n-octylphosphine oxide modified electrode in a ternary complex system are characterized in this report by infrared and X-ray photoelectron spectroscopies . It states that the preconcentration efficiency is enhanced greatly with the formation of the ternary complex, Eu(TTA)3 (TOPO)2, during the preconcentration process of the modified electrode. During the complexing preconcentration process, not all the tri-n-octylphosphine oxides at the electrode surface have the complex activity . Only those sites with the complex activity and favorable steric arrangement circumstance take part in the preconcentration complex reaction . It is shown that the Eu in the ternary complex at the electrode surface is reduced during the cathodic stripping process.
出处
《高等学校化学学报》
SCIE
EI
CAS
CSCD
北大核心
1991年第9期1164-1166,共3页
Chemical Journal of Chinese Universities
关键词
化学修饰
电极
TOPO
富集
溶出
Chemically modifided electrode, Electrode surface characterization, Infrared spectra, X-ray photoelectron spectroscopy
