Enantiomeric separation of β-blockers and tryptophan using heparin as stationary and pseudostationary phases in Capillary Electrophoresis

LORENA L. SOMBRA; PATRICIA W. STEGE

CHIRALITY

WILEY-LISS, DIV JOHN WILEY & SONS INC

Lugar: New York; Año: 2018

0899-0042

Abstract: The separation methods of the enantiomers of two β-blockers and trypthophan were studied using capillary electrochromatography (CEC) with heparin covalently as well as non-covalently, bonded onto the capillary inner wall as stationary phase and electrokinetic chromatography (EKC) with heparin as pseudostationary phase. In the case of heparin, used as a stationary phase, the method was unable to resolve enantiomers in both cases β-blockers and tryptophan. On the other hand, when heparin was used as a pseudostationary phase, the resolution of the enantiomers was obtained only with APTES which were immobilised onto the inner phase of the capillary.The results of this study let us infer that the electrostatic, hydrophobic, and steric interactions were involved in the separation mechanisms. The separation was archived in less than 10 min under the optimized conditions: 30 mM phosphate buffer (pH 2.5) with the adding of 15 mg/mL of heparin at 15°C and 10kV. The usefulness of heparin as a chiral selector both in EKC using APTES attached to the capillary was demonstrated for the first time. The developed method was powerful, sensitive and fast and it could be considered an important alternative to conventional methods used for chiral separation.