Analysis of polyethoxylated surfactants in microemulsion-oil–water systems

• Published in: Analytica chimica acta Vol. 405; no. 1; pp. 267 - 275
• Main Authors: Márquez, N, Bravo, B, Chávez, G, Ysambertt, F, Salager, J.L
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 24-01-2000; Elsevier
• Subjects: Analytical chemistry; Chemistry; Chromatographic methods and physical methods associated with chromatography; Colloidal state and disperse state; Emulsions. Microemulsions. Foams; Exact sciences and technology; General and physical chemistry; HPLC of nonionic surfactants; Other chromatographic methods; Partition of nonionic surfactants; Polyethoxylate surfactants; HPLC of nonionic surfactants; Polyethoxylate surfactants; Partition of nonionic surfactants; Structure effect; Chemical analysis; Non ionic surfactant; Chain length; HPLC chromatography; Partition coefficient; Isocratic condition; Multicomponent analysis; Micellar critical concentration; Ultraviolet detector; Qualitative analysis; Oil water microemulsion; Physicochemical properties
• ISSN: 0003-2670; 1873-4324
• DOI: 10.1016/S0003-2670(99)00759-X

A normal-phase method for the separation of ethylene oxide number (EON) oligomers by high performance liquid chromatography (HPLC) is described. Isocratic HPLC with mixed solvent on silica column allows to separate oligomers up to EON
=
18. Gradient programming moves the limit up to EON
=
20. For higher EON values (up to 50) a NH
2 column has to be used, either with isocratic or gradient mode. Detection was performed using UV detector. The partition of surfactant in the oil–water system over the entire concentration range below the CMC was determined. Surfactant-oil–water systems were studied according to the unidimensional scan. The surfactant content in the oil, microemulsion and water phases was determined by HPLC. The addition of a lipophilic alcohol in a Winsor III system produced a decrease in the partition coefficient of the surfactant between the water and oil phases.