Polymeric micelle as the pseudostationary phase in electrokinetic chromatography

Area of Science:

• Analytical Chemistry
• Polymer Science
• Separation Science

Background:

• Polymeric micelles offer unique properties for separation science.
• Electrokinetic chromatography (EKC) is a powerful separation technique.
• Developing efficient pseudostationary phases (PSPs) is crucial for EKC performance.

Purpose of the Study:

• To develop a simple, green method for preparing polymeric micelles using P(MMA-co-MAA) copolymers.
• To investigate the application of these polymeric micelles as a novel PSP in EKC.
• To assess the separation performance for structurally similar corticosteroids.

Main Methods:

• Polymeric micelles were synthesized via neutralization of amphiphilic random copolymers P(MMA-co-MAA) in an aqueous medium.
• Transmission Electron Microscopy (TEM) and Dynamic Light Scattering (DLS) were used to characterize micellar microstructure (size, morphology, charge).
• Electrokinetic chromatography (EKC) was employed to separate hydrocortisone, prednisolone, and prednisone, optimizing polymer concentration and pH.

Main Results:

• Well-defined spherical polymeric micelles were formed, with size and shape dependent on polymer concentration and pH.
• Optimal conditions (0.048 mM P(MMA-co-MAA), pH 9.2) yielded monodisperse spherical micelles.
• Baseline separation of three corticosteroids was achieved within 7.4 minutes, demonstrating high efficiency and selectivity compared to other EKC methods.
• Analysis of cosmetic samples showed high recovery rates (97.3%-113%).

Conclusions:

• The developed polymeric micelle system is a promising, green, and efficient PSP for EKC.
• This method offers a rapid, selective, and effective approach for corticosteroid separation.
• The separation mechanism was identified as reverse-phase interaction, applicable to real-world sample analysis.