Surfactant sensitive sensor
|Kurzbeschreibung||Surfactant sensitive electrode for potentiometric titration of ionic and nonionic surfactants in aqueous solutions|
The potential of a solution containing surfactants is measured as a function of the titrant added. Potentiometric titrations are indicated with a surfactant sensitive electrode (SSE). The potential is formed by interaction between the ion carrier in the membrane and the analyte in the sample solution. It can be measured against a reference electrode at zero current. The potential-volume E-V curves obtained are usually S-shaped and can be easily evaluated for the largest change in potential. Thus, the standard evaluation is selected in the titration method. If the curve shows a pronounced asymmetric profile, then the asymmetric evaluation can be used.
Anionic (cationic) surfactants are titrated with cationic (anionic) surfactants. Near the equivalence point, a precipitate is formed, and the solution becomes turbid. In the case of nonionic surfactants, addition of a specific activator prior to titration is necessary to form a complex between analyte and titrant.