显色剂结构与胶束增敏作用的关系 Ⅱ.Cadion,Cadion 2B的比较

The Relationship between Micellar Sensitization and the Structure of the Organic Chromogenic Reagent Ⅱ. Comparison Cadion with Cadion 2B

本文从表面活性剂对Cd(Ⅱ)-Cadion和Cd(Ⅱ)-Cadion 2B作用的不同,研究了有机显色剂分子结构与胶束增敏作用的关系,发现在无表面活性剂存在时,Cd(Ⅱ)-Cadion 2B的灵敏度高于Cd(Ⅱ)-Cadion,当加入适量表面活性剂后,Cadion体系的增敏效应有如下顺序:SDBS>混合表面活性剂>SDS。阳离子表面活性剂无增敏效应。以Triton X-100为例,分别测定了显色剂及其配合物所在胶束微环境中的_(off),在胶束中的分配系数,还另用分光光度法和析相法探求增溶位。结果表明:(1)具有两亲结构的被增溶物增溶于胶束的栅状层,其能否进入栅状层及进入栅状层的深浅,决定于被增溶物分子的横断面的大小和两亲结构明显程度。(2)在胶束栅状层,受“刚性不对称微环境”的作用产生增敏作用。(3)从研究Cd(Ⅱ)-Cadion和Gd(Ⅱ)-Cadion 2B的分子结构表明:Cd(Ⅱ)-Cadion 2B的横断面大于Cd(Ⅱ)-Cadion,而两亲结构又比Cd(Ⅱ)-Cadion不明显,这是Cd(Ⅱ)-Cadion 2B胶束增敏率小于Cd(Ⅱ)-Cadion的主要原因。

In this paper, the relationship between micellar sensitization and the structure of the organic chromogenic reagent was studied from many aspects. We found that the sensitivity of Cd(Ⅱ)-Cadion 2B was higher than Cd(Ⅱ)-Cadion without any surfactants. But the sensitivity of Cd(Ⅱ)-Cadion was enhanced more pronouncedly than that of Cd(Ⅱ)-Cadion 2B with addition of surfactants. The enhancement by surfactants had such sequence: SDBS>mixed surfactants>SDS>cationic surfactants. Take Triton X-100 as an example. The effective dielectric constants and distribution coefficients of Cadion, Cd(Ⅱ)-Cadion, Cadion 2B, Cd(Ⅱ)-Cadion 2B in micellar solution were determined. The location and orientation of the solubilizates in the micelles were studiiod also by means of micelle separated method and spectrophotometry. The structure of Cd(Ⅱ)-Cadion and Cd(Ⅱ)-Cadion 2B were investigated. Some conclutions were drawn from these results: It was confirmed that the amphiphilic structure of the reagent and its complex played an important role in the micellar sensitizing effect. The solubilizate had pronouced amphiphilic structure causing solubilized into the palisade layer of micelle. The area cross section and the amphiphilic structure of the solubilizate determined the sensitizing effect. In suoh situation the enriching effect of the micelles and the 'rigid unsymmetric microenvironment' effect might take place. As a result the system was sensitized. According to this view and the structure of Cd(Ⅱ)-Cadion and Cd(Ⅱ)-Gadion 2B, the above results were discussed.