Surfactant to dye binding degree-based methodology for the determination of ionic amphiphilic compounds.
A new analytical measurement parameter based on the effect of amphiphilic substances on the degree of binding of a surfactant to dye molecules, which induce the formation of surfactant premicellar aggregates, is presented. The theory for dye-surfactant intermolecular interactions in mixed surfactant systems, which assumes a mononuclear model for the formation of dye-induced premicellar aggregates, has been used to derive an expression that provides linear calibrations for the determination of amphiphilic compounds. The dye-surfactant interactions involved have been investigated, and the variables affecting the measurement analytical parameter have been discussed. The analytical applicability of the surfactant-dye binding degree method is demonstrated by quantifying major anionic surfactants at the nanograms-per-milliliter level and determining the total concentration of these amphiphilic substances in sewage samples (average recoveries ranged from 98 to 102%).
Department of Analytical Chemistry, Faculty of Sciences, University of Córdoba, Edificio Marie Curie, Campus de Rabanales, 14071 Córdoba, Spain.
Rafael
R
Fabios
María Dolores
MD
Sicilia
Soledad
S
Rubio
Dolores
D
Pérez-Bendito