Development of a chiral stationary phase based on cinchonidine. Comparison with a quinine-based chiral column

KEUNCHKARIAN, S.; OSORIO GRISALES, J.; J. M. PADRÓ; BOERIS, S. ; CASTELLS, C. B.

CHIRALITY

WILEY-LISS, DIV JOHN WILEY & SONS INC

Lugar: New York; Año: 2012 vol. 24 p. 512 - 518

0899-0042

A chiral anion-exchanger stationary phase based on cinchonidine (CD) was developed. Two columns were packed with and without endcapping (EC) treatment (CD-chiral stationary phase [CD-CSP(EC)] and [CD-CSP], respectively) and studied for their ability to separateN-2,4-dinitrophenyl a-amino acids (DNP-amino acids) enantiomers over a temperature rangeof 10?40 C with a hydro-organic buffer mobile phase. The more hydrophobic, endcapped stationary phase showed significantly larger retentive capacity than the non-endcapped one. Theapparent thermodynamic transfer parameters of the enantiomers from the mobile to both CSPswere estimated from van?t Hoff plots within the cited temperature range. Similar studies withtwo natural quinine-based columns (QN-CSP and QN-CSP(EC)) were previously reported. Inthis work, a critical comparison in the chiral recognition ability to DNP-amino acids of thesecinchonidine and QN-based chiral columns was drawn. It has been found that QN-based CSPsshow greater chiral recognition capability towards these derivatives than CD-CSPs. Theinfluence of the QN methoxy group on the equilibrium constants of the enantioselectiveinteraction between these DNP-amino acids with these two cinchona CSPs could be assessed