Enantioseparation of underivatized amino acids by capillary liquid chromatography. 2. (N, S-dioctyl-(D)-penicillamine) ligand exchange chiral stationary phase

Daher F. A., Santos N. G. P., Maciel E. V. S., Lanças F. M.

Keywords: Enantiomeric separation, capillary liquid chromatography; chiral ligand exchange stationary phase; underivatized amino acids, Cu(II) complexes, (N, S-dioctyl-(D)-penicillamine)

Abstract: Chiral capillary liquid chromatography of underivatized amino acids was investigated by using a chiral ligand exchange stationary phase (N, S-dioctyl-(D)-penicillamine) and a mobile phase containing Cu (II) ion as a complexion agent. The direct separation of four racemic α-amino acids was achieved and the influence of experimental variables such as the mobile phase composition, copper (II) concentration, pH on the retention, resolution, separation factor (α), and retention factor (k), was studied. The amino acids were isocratically separated using 2 mmol/L Cu(II) (pH 5.3)/methanol/water (15:85, v/v) as the mobile phase at a flow rate of 8µL/min, and determined by UV detection at 254 nm. The results showed that capillary liquid chromatography using a chiral stationary phase and Cu(II) in the mobile phase is an up-and-coming alternative technique for the enantiomeric separation of amino acids.

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