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.

Referências Bibliográficas

1. Maciel EVS, de Toffoli AL, Lanças FM. Current status and future trends on automated multidimensional separation techniques employing sorbent-based extraction columns. J Sep Sci 2019;42:258–72. https://doi.org/10.1002/jssc.201800824.
2. Vargas Medina DA, Maciel EVS, de Toffoli AL, Lanças FM. Miniaturization of liquid chromatography coupled to mass spectrometry. TrAC Trends Anal Chem 2020;128:115910. https://doi.org/10.1016/j.trac.2020.115910.
3. Maciel EVS, de Toffoli AL, Sobieski E, Domingues Nazário CE, Lanças FM. Miniaturized liquid chromatography focusing on analytical columns and mass spectrometry: A review. Anal Chim Acta 2020;1103:11–31. https://doi.org/10.1016/j.aca.2019.12.064.
4. D’Orazio G. Chiral analysis by nano-liquid chromatography. TrAC Trends Anal Chem 2020;125:115832. https://doi.org/10.1016/j.trac.2020.115832.
5. Wilson SR, Berg HE, Roberg-Larsen H, Lundanes E. Hyphenations of one-dimensional capillary liquid chromatography with mass spectrometry. Hyphenations Capill. Chromatogr. with Mass Spectrom., Elsevier; 2020, p. 319–67. https://doi.org/10.1016/B978-0-12-809638-3.00009-0.
6. Fanali S. Nano-liquid chromatography applied to enantiomers separation. J Chromatogr A 2017;1486:20–34. https://doi.org/10.1016/j.chroma.2016.10.028.
7. Fanali S, D’Orazio G, Farkas T, Chankvetadze B. Comparative performance of capillary columns made with totally porous and core–shell particles coated with a polysaccharide-based chiral selector in nano-liquid chromatography and capillary electrochromatography. J Chromatogr A 2012;1269:136–42. https://doi.org/10.1016/j.chroma.2012.06.021.
8. Sharaf El-Din MMK, Attia KAM, Nassar MWI, Kaddah MMY. Development and validation of a copper ligand-exchange chromatographic method for the estimation of D-lactic acid in Ringer-lactate solution. Talanta 2018;189:86–91. https://doi.org/10.1016/j.talanta.2018.06.068.
9. Alizadeh T, Shamkhali AN. Chiral resolution of salbutamol in plasma sample by a new chiral ligand-exchange chromatography method after its extraction with nano-sized imprinted polymer. J Chromatogr B 2016;1009–1010:96–106. https://doi.org/10.1016/j.jchromb.2015.12.021.
10. Kumar R, Bhushan R. Indirect chiral ligand exchange chromatography for enantioseparation: a modification of conventional techniques. RSC Adv 2014;4:50130–6. https://doi.org/10.1039/C4RA07061E.
11. Davankov VA, Bochkov AS, Kurganov AA, Roumeliotis P, Unger KK. Separation of unmodified α-amino acid enantiomers by reverse phase HPLC. Chromatographia 1980;13:677–85. https://doi.org/10.1007/BF02303437.
12. Mangelings D, Eeltink S, Vander Heyden Y. Recent developments in liquid and supercritical fluid chromatographic enantioseparations, 2020, p. 453–521. https://doi.org/10.1016/B978-0-444-64070-3.00009-6.
13. Ianni F, Pucciarini L, Carotti A, Natalini S, Raskildina GZ, Sardella R, et al. Last ten years (2008-2018) of chiral ligand-exchange chromatography in HPLC: An updated review. J Sep Sci 2019;42:21–37. https://doi.org/10.1002/jssc.201800724.