STRUCTURAL SELECTIVITY PROVIDED BY STARBURST DENDRIMERS AS PSEUDOSTATIONARY PHASE IN ELECTROKINETIC CHROMATOGRAPHY

Starburst dendrimers (SBDs) were used as a pseudostationary phase in electrokinetic chromatography (EKC) of hydrophobic compounds. The selectivity of SBD-mediated EKC (SBD-EKC) was different from those in micellar EKC (MEKC) systems, in spite of the apparent structural resemblance between micelles and SBDs. The SBDs provided similar selectivity as polymer gel packing materials in reversed-phase liquid chromatography (RPLC), showing little selectivity for alkyl groups and clear preference for aromatic compounds, especially for rigid, planar polynuclear aromatic hydrocarbons. The alkylation of SBDs resulted in the increased retention and hydrophobic selectivity while maintaining the preference toward rigid, planar compounds. These SBDs can be used in a full range of methanol-water mixtures, showing the retention decrease with the increase in methanol content as in RPLC. The results suggest that SBDs can make a support for various pseudostationary phases for EKC.