DETERMINATION OF NEOTAME BY HIGH-PERFORMANCE CAPILLARY ELECTROPHORESIS USING ?-CYCLODEXTRIN AS A CHIRAL SELECTOR

摘要

An electrokinetic chromatographic method was developed for the chiral separation of neotame, a new high intensity artificial sweetener, using a chiral separating agent heptakis 2,3,6-tri-o-methylbetacyclodextrin. The purpose of this study was to better understand diastereomer-resolution interactions between neotame and the chiral separating agent. Molecular docking studies were performed to elucidate the mechanism of the separation. The optimum conditions were 50mM phosphate buffer, pH 5.5, applied voltage 20 kV, cassette temperature of 30℃, and a 4 s sample injection time. The calibration curve showed good linearity (r~2>0.99) with recoveries for both diastereomers, ranging from 95.66–99.00% and the limits of detection for L,L-neotame and D,D-neotame were 0.01857 and 0.08214mM, respectively. The developed method showed analytical precision with relative standard deviations (n=5) of 1.20% and 1.17% with respect to migration time and peak area, respectively. A large difference in the interaction energies observed between the diastereomers represents a significant differentiation. The results showed that both electrostatic and hydrophobic interactions played a significant role in stabilizing their inclusion complexes and consequently supported the elution order based on their differential stabilities.