Determination of aggregation thresholds of UV absorbing anionic surfactants by frontal analysis continuous capillary electrophoresis.
Aggregation of anionic surfactants was investigated by frontal analysis continuous capillary electrophoresis (FACCE), a method involving the continuous electrokinetic introduction of the surfactant sample into the separation capillary. This process results in a partial separation of the monomeric and aggregated forms without perturbing the monomer-aggregate equilibrium. The critical micelle concentration (CMC) can then be easily derived from the height of the firstly detected migration front, corresponding to the monomeric form. This approach is exemplified with octyl and dodecylbenzenesulfonates and compared with conductimetry and surface tension measurements. FACCE turns out to be an effective method for the determination of CMC and intermediate aggregation phenomena with very small sample and short time requirements.
Le Saux
Thomas
T
Laboratoire d'Electrochimie et Chimie Analytique, Ecole Nationale Supérieure de Chimie de Paris, UMR CNRS 7575, 11 Rue Pierre et Marie Curie, F-75231 Paris 5, France.
Varenne
Anne
A
Gareil
Pierre
P
D000838:Anions / Q000737:chemistry*; D004553:Electric Conductivity; D019075:Electrophoresis, Capillary / Q000379:methods*; D013500:Surface Tension; D013501:Surface-Active Agents / Q000737:chemistry*; D014466:Ultraviolet Rays
D000838:Anions; D013501:Surface-Active Agents