Cationic and perfluorinated polymeric pseudostationary phases for electrokinetic chromatography

Area of Science:

• Analytical Chemistry
• Chromatography

Background:

• Separation selectivity in electrokinetic chromatography (EKC) depends on pseudostationary phase (PSP) chemistry and solvent properties.
• Micellar PSPs exhibit varied selectivity based on surfactant type (anionic/cationic) and composition (hydrocarbon/fluorocarbon).
• Polymeric PSPs offer unique selectivity advantages in chromatographic separations.

Purpose of the Study:

• To introduce and characterize four novel cationic polymeric PSPs for EKC.
• To compare the performance and selectivity of these polymers against conventional micellar PSPs.
• To investigate the influence of perfluorinated pendant groups on polymer PSP selectivity.

Main Methods:

• Synthesis and characterization of four cationic polymeric PSPs.
• Evaluation of PSP performance and selectivity in EKC.
• Comparative analysis with micellar PSPs of similar structures.

Main Results:

• The four polymers exhibited solvation characteristics and selectivity profiles closely resembling cationic micelles.
• Polymers demonstrated greater cohesiveness and polarity compared to hydrocarbon micellar counterparts.
• Fluorocarbon polymers showed preferential interaction with fluorocarbon solutes and enhanced hydrogen bonding, but selectivity effects were less pronounced than in fluorocarbon micelles.

Conclusions:

• Cationic polymeric PSPs provide a viable alternative to micellar phases in EKC.
• Selectivity in these polymeric systems appears influenced by both the cationic head groups and the polymer backbone's overall character.
• The impact of fluorocarbon moieties on selectivity may be moderated by the polymer structure, unlike in micellar systems.