Enantiomer separation of flavour and fragrance compounds by liquid chromatography using novel urea-covalent bonded methylated β-cyclodextrins on silica

A novel methylated β-cyclodextrin chiral stationary phase (CSP-ME), which was chemically immobilised onto porous silica via multiple urea-linkages was synthesised. The CSP-ME chiral stationary phase depicted good enantiomer separation abilities for some well-known flavour as well as fragrance compounds using high-performance liquid chromatography under reverse phase conditions. The optimum resolution for α-ionone, 3-methyl-α-ionone, flavanone, 5-methoxyflavanone, 6-methoxyflavanone, 7-methoxyflavanone, hesperetin, naringenin and taxifolin was achieved using a mobile phase composition consisting of 1 wt.% triethylammonium acetate buffer (pH 4.68)–methanol. The effects of pH of triethylammonium acetate buffer and the methanol–acetonitrile content of the mobile phase composition on their retention time and resolution were examined to optimise the separation conditions.