Separation of structural homologues of alkylphenols and isomers of 4-nonylphenol by cyclodextrin-modified micellar electrokinetic chromatography

The potential of cyclodextrin-modified micellar electrokinetic chromatography (CD/MEKC) for separating structural homologues of alkylphenols and isomers of 4-nonylphenol (4-NP) was evaluated and compared with ordinary MEKC. The addition of cyclodextrins to the separation buffer containing sodium dodecyl sulphate (SDS) significantly improved the resolution of the alkylphenol (AP) homologues with long hydrocarbon chains, and especially those of 4-NP isomers, while reducing the analysis time. The operating conditions in the CD/MEKC were optimized, with an emphasis on investigating the effects of the type and concentration of CD, SDS concentration, acetonitrile concentration and sample stacking on the separation of 4-NP isomers.