Studies on the physical and chemical mechanisms of separation of enantiomeric mixtures

Author: Bezhan Chankvetadze
Keywords: Enantioseparations, High-performance liquid chromatography, Capillary electrochromatography, Nano-liquid chromatography
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Studies on the physical and chemical mechanisms of separation of enantiomeric mixtures Bezhan Chankvetadze Chair of Physical and Analytical Chemistry and the Institute of Physical and Analytical Chemistry, Iv. Javakhishvili Tbilisi State University, Chavchavadze Ave 1, 0179 Tbilisi, Georgia bezhan.chankvetadze@tsu.ge Enantiomers of chiral compounds such as pharmaceuticals, agrochemicals food additives, etc. are characterized with different biological activities. This makes necessary a development of chiral compounds for future applications in enantiomerically pure form. Separation of enantiomers of chiral compounds is necessary for their analysis, as well as a useful tool for their large-scale production. Thus, separation of enantiomers of chiral compounds represents one of the hot topics of current chemistry [1]. In this presentation the results of our studies on development, commercialization and application of novel chiral stationary phases (CSP) for separations of enantiomers using high-performance liquid chromatography (HPLC), nano-liquid chromatography (CLC) and capillary electrochromatography (CEC) are summarized. In the first part of the presentation the emphasis will be made on novel phenylcarbamate derivatives of cellulose and amylose as useful CSPs for analytical and preparative scale separation of enantiomers. These novel materials are applicable for HPLC enantioseparations in combination with normal phase-, polar organic mobile phase and reversed-phase eluents, as well as for enantioseparations in supercritical fluid chromatography (SFC) at higher pressure [1-5]. In the second part of the presentation the screening results on 5 commercially available representatives of this series of chiral columns will be discussed with major emphasis on the complementary properties of various chiral selectors and mobile phases. The effect of fine tuning of the properties of these materials and separation conditions on resolution of enantiomers of various compounds will be discussed in detail using the examples of challenging separations. In the final part of the presentation newly observed reversal of the enantiomer elution order of some chiral drugs and amino acid derivatives by variation of separation temperature and composition of the mobile phase will be discussed [1, 6-8]. References: [1] B. Chankvetadze, J. Chromatogr. A, 1269 (2012) 26. [2] B. Chankvetadze, E. Yashima, Y. Okamoto, Chem. Lett., 1993 (4) 617. [3] B. Chankvetadze, E. Yashima, Y. Okamoto, J. Chromatogr. A., 670 (1994), 39. [4]. B. Chankvetadze, E. Yashima, Y. Okamoto, A, 694 (1995) 101. [5] B. Chankvetadze, L. Chankvetadze, Sh. Sidamonidze, E. Kasashima, E. Yashima and Y. Okamoto, J. Chromatog. A, 787 (1997) 67-77. [6] K. Lomsadze, G. Jibuti, T. Farkas, B. Chankvetadze, J. Chromatogr. A, 1234 (2012) 50. [7] G. Jibuti, A. Mskhiladze, N. Takaishvili, L. Chankvetadze, M. Karchkhadze, T. Farkas, B. Chankvetadze, J. Sep. Sci., 35 (2012) 2529. [8] I. Matarashvili, L. Chankvetadze, S. Fanali, T. Farkas, B. Chankvetadze, J. Sep. Sci., 36 (2013) 140.