In situ synthesis of di-n-butyl L-tartrate-boric acid complex chiral selectorand its application in chiral microemulsion electrokinetic chromatography

摘要

A novel procedure for in situ assembling a complex chiral selector, di-n-butyl L-tartrate-boric acidcomplex, by the reaction of di-n-butyl L-tartrate with boric acid in a running buffer was reportedand its application in the enantioseparation of n-blockers and structural related compounds by chiralmicroemulsion electrokinetic chromatography (MEEKC) has been demonstrated. In order to achieve agood enantioseparation, the effect of dibutyl L-tartrate and sodium tetraborate concentration, surfactantidentity and concentration, cosurfactant, buffer pH and composition, organic modifiers, as well as appliedvoltage and capillary length were investigated. Ten pairs of enantiomers that could not be separated withonly dibutyl L-tartrate, obtained good chiral separation using the complex chiral selector; among them,seven pairs could be baseline resolved under optimized experimental conditions. The fixation of chiralcenters by the formation of five-membered rings, and being oppositely charged with basic analytes werethought to be the key factors giving the complex chiral selector a superior chiral recognition capability.The effect of the molecular structure of analytes on enantioseparation was discussed in terms of molecularinteraction.