Enantiomeric Separation of Chiral Pesticides by Permethylated β-Cyclodextrin Stationary Phase in Reversed Phase Liquid Chromatography

Enantiomeric separation of six chiral pesticides by high-performance liquid chromatography with permethylated beta-cyclodextrin (beta-PM) chiral stationary phase were tested under reversed phase conditions. The influences of water composition from 10% to 45% in the mobile phase and column temperatures from 0 degrees C to 40 degrees C on the separation were investigated. Chromatographic parameters including selectivity factors (alpha), retention factors (k), and resolution factors (Rs) were selected to evaluate the separation efficiency in different conditions. Baseline separation was obtained for diclofop-methyl, fenoxaprop-ethyl, tebuconazole, and triticonazole, and Rs of these pesticides were greater than 1.5. However, etoxazole and lactofen were partially separated in all experiments. The parameters of alpha and k were decreased by the increasing temperature for all investigated pesticides, but the best resolution for etoxazole (Rs = 0.94) and lactofen (Rs = 0.59) was achieved at 20 degrees C, different from the Rs tendency of other pesticides, which decreased with a temperature increase. (C) 2016 Wiley Periodicals, Inc.