Stacking and Sweeping in Cyclodextrin-Modified MEKC for Chiral Separation of Hexaconazole, Penconazole and Myclobutanil

A CD-MEKC method for the on-line preconcentration and chiral separation of three chiral triazole fungicides, namely hexaconazole, penconazole and myclobutanil is reported. Simultaneous enantioseparation of the three triazole fungicides was successfully achieved by the CD-MEKC system containing 40 mM HP-gamma-CD + 50 mM SDS in 25 mM phosphate buffer (pH 3.0) solution. Stacking with a reverse migrating micelle (SRMM) and sweeping were then used in this study as two on-line preconcentration methods to enhance the concentration sensitivity. The results indicate that sweeping-CD-MEKC is superior to SRMM-CD-MEKC in terms of the sensitivity enhancement factor (SEF) of the three triazole fungicides ranging from 62- to 67-fold. This is the first report on the chiral separation of hexaconazole, penconazole and myclobutanil by SRMM-CD-MEKC and sweeping-CD-MEKC methods.