Enantioseparations of Triazole Chiral Pesticides on Two β-Cyclodextrin-bonded Stationary Phases with Different Linkages by HPLC

Two kinds of new beta-cyclodextrin-bonded chiral stationary phases(CDSP and NCDSP) with carbamate and urea linkages were prepared using ordered mesoporous material SBA-15 as matrix, beta-cyclodextrin and 6-amino beta-cyclodextrin as ligands via the addition reactions of OH and NH2 groups of beta-cyclodextrin with active 3-isocyanatopropyltriethoxy silane, respectively. The enantioseparation properties of two new stationary phases were evaluated and compared by adopting 10 kinds of common chiral triazole pesticides as probes including triticonazole diniconazole, hexaconazole, tebuconazole, etc. in reversed-phase mode. The results show that CDSP and NCDSP exhibited excellent and fast chiral separation ability for triazole pesticides within 30 min. Nine and eight kinds of triazole enantiomers were separated on CDSP and NCDSP at room temperature with methanol/H2O and acetonitrile/H2O as mobile phase, respectively. The chiral selectivity factor(alpha) are 1. 29 for triticonazole with a resolution of 3. 84 for CDSP and 1. 28 for diniconazole with a resolutions of 3. 23 for NCDSP. It was found that triazole pesticides with appropriate size and -OH groups on CDSP and NCDSP had better separation effect, indicating that the inclusion, hydrogen bonding, steric hindance and other synergic forces between beta-cyclodextrin ligand and solutes could contribute enantioseparations. The surface loading of CDSP and NCDSP by different batches were 0. 139-0. 156 and 0.120-0.137 mu mol/m(2), respectively, indicating that the new preparation methods have good reproducibility. Compared with the commodity coated cellulose column, the new cyclodextrin stationary phases with urea and carbamate linkages were more stable, more practical, easy preparation and low cost. The prepared beta-cyclodextrin stationary phases have good prospects in the enantiomeric monitoring of triazole pesticides residues.