Characterization and application of molecular binary mixed molecular micelles of sodium 10-undecenyl sulfate and sodium N-undecenyl leucinate as pseudostationary phases in micellar electrokinetic chromatography

Poly (sodium 10-undecenyl sulfate) (poly SUS), poly (sodium 10-undecenyl leucinate) (poly SUL), and their five molecular binary mixed micelles with varied SUS:SUL composition were prepared. The purity of these molecular micelles was confirmed by elemental analysis. Their partial specific volume, aggregation number, methylene selectivity, polarity, phase ratio, mobility, and elution window values were determined using a variety of analytical techniques. These molecular micelles were then evaluated as pseudostationary phases in micellar electrokinetic chromatography (MEKC) for separation of benzene derivatives with a wide range of chemical properties. Elemental analysis results reveal that the ratio of the two surfactants in the binary mixture does not change significantly during the polymerization process. Poly SUS was found to have the lowest partial specific volume and it increases gradually with an increase of SUL mole fraction. Poly SUL was found to provide the most hydrophobic environment for test solutes. Based on the retention results, the strength of interaction between the molecular micelles and the analytes was found to follow the following order: NHB>HBA>HBD. This order indicates that the hydrophobic interaction plays a major role in retention of benzene derivatives.