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Yuan S, Zhao L, Wang F, Tan L, Wu D. Recent advances of optically active helical polymers as adsorbents and chiral stationary phases for chiral resolution. J Sep Sci 2023; 46:e2300363. [PMID: 37480172 DOI: 10.1002/jssc.202300363] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2023] [Revised: 07/02/2023] [Accepted: 07/03/2023] [Indexed: 07/23/2023]
Abstract
Chiral resolution is very important and still a big challenge due to different biological activity and same physicochemical property of one pair (R)- and (S)-isomer. There is no doubt that chiral selectors are essentially needed for chiral resolution, which can stereoselectively interact with a pair of isomers. To date, a large amount of optically active helical polymers as chiral selectors have been synthesized via two strategies. First, the target helical polymers are derived from natural polysaccharide such as cellulose and amylose. Second, they can be synthesized by polymerization of chiral monomers. Alternatively, an achiral polymer is prepared first followed by static or dynamic chiral induction. Furthermore, a part of them is harnessed as chiral stationary phases for chromatographic chiral separation and as chiral adsorbents for enantioselective adsorption/crystallization, resulting in good enantioseparation efficiency. In summary, the present review will focus on recent progress of the polymers with optical activity for chiral resolution, especially the literature published in the past 10 years. In addition, development prospects and future challenges of optically active helical polymers will be discussed in detail.
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Affiliation(s)
- Shuyi Yuan
- Jiangsu Key Laboratory of Advanced Materials and Technology, School of Petrochemical Engineering, Changzhou University, Changzhou, P. R. China
| | - Lei Zhao
- Jiangsu Key Laboratory of Advanced Materials and Technology, School of Petrochemical Engineering, Changzhou University, Changzhou, P. R. China
| | - Fangqin Wang
- Jiangsu Key Laboratory of Advanced Materials and Technology, School of Petrochemical Engineering, Changzhou University, Changzhou, P. R. China
| | - Lilan Tan
- Jiangsu Key Laboratory of Advanced Materials and Technology, School of Petrochemical Engineering, Changzhou University, Changzhou, P. R. China
| | - Datong Wu
- Jiangsu Key Laboratory of Advanced Materials and Technology, School of Petrochemical Engineering, Changzhou University, Changzhou, P. R. China
- Department of Molecular and Macromolecular Chemistry, Graduate School of Engineering, Nagoya University, Nagoya, Japan
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Fouad A, Ibrahim D, Adly FG, Ghanem A. An insight into chiral monolithic stationary phases for enantioselective high-performance liquid chromatography applications. J Sep Sci 2019; 42:2303-2340. [PMID: 31050176 DOI: 10.1002/jssc.201900159] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2019] [Revised: 04/17/2019] [Accepted: 04/17/2019] [Indexed: 02/02/2023]
Abstract
In this review, three main classes of chiral monolithic stationary phases, namely silica-, organic polymer-, and hybrid-based monolithic stationary phases, are covered. Their preparations, applications, and advantages compared with the conventional-packed and open-tubular capillary columns are discussed. A detailed description of the different types and techniques used for the introduction of chiral selectors into the monolithic matrices such as immobilization, functionalization, coating, encapsulation, and bonding. Special emphasis is given to the recent developments of chiral selectors in HPLC monolithic stationary phases during the past 18 years.
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Affiliation(s)
- Ali Fouad
- Chirality Program, School of Science, Faculty of Science and Technology, University of Canberra, ACT, Australia.,Pharmaceutical Chemistry Department, Faculty of Pharmacy, Al-Azhar University, Assiut, Egypt
| | - Diana Ibrahim
- Chirality Program, School of Science, Faculty of Science and Technology, University of Canberra, ACT, Australia
| | - Frady G Adly
- Chirality Program, School of Science, Faculty of Science and Technology, University of Canberra, ACT, Australia
| | - Ashraf Ghanem
- Chirality Program, School of Science, Faculty of Science and Technology, University of Canberra, ACT, Australia
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3
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A facile and efficient single-step approach for the fabrication of vancomycin functionalized polymer-based monolith as chiral stationary phase for nano-liquid chromatography. J Chromatogr A 2018; 1557:43-50. [DOI: 10.1016/j.chroma.2018.05.004] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2018] [Revised: 04/25/2018] [Accepted: 05/02/2018] [Indexed: 11/17/2022]
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4
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Fouad A, Ghanem A. Immobilized Chiral Selectors on Monolithic High-Performance Liquid Chromatography Columns. ADVANCES IN CHROMATOGRAPHY 2017. [DOI: 10.1201/9781315116372-5] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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5
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Xiao X, Wang W, Zhang Y, Jia L. Facile preparation of fibrin coated open tubular column for characterization of monoclonal antibody variants by capillary electrochromatography. J Pharm Biomed Anal 2017; 140:377-383. [DOI: 10.1016/j.jpba.2017.03.014] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2017] [Revised: 03/06/2017] [Accepted: 03/09/2017] [Indexed: 01/13/2023]
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6
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Rocco A, Maruška A, Fanali S. Enantiomeric separations by means of nano-LC. J Sep Sci 2013; 36:421-44. [DOI: 10.1002/jssc.201200886] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2012] [Revised: 10/24/2012] [Accepted: 10/26/2012] [Indexed: 11/05/2022]
Affiliation(s)
- Anna Rocco
- Department of Biochemistry and Biotechnologies; Vytautas Magnus University; Kaunas Lithuania
- Institute of Chemical Methodologies; Consiglio Nazionale delle Ricerche; Rome Italy
| | - Audrius Maruška
- Department of Biochemistry and Biotechnologies; Vytautas Magnus University; Kaunas Lithuania
| | - Salvatore Fanali
- Institute of Chemical Methodologies; Consiglio Nazionale delle Ricerche; Rome Italy
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Yao C, Tang S, Yan C, Yao HM, Tade MO. Preparation of a Monolith with Covalently Bound Bovine Serum Albumin for Capillary Electrochromatography. ANAL LETT 2012. [DOI: 10.1080/00032719.2012.689793] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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8
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Lu J, Ye F, Zhang A, Wei Z, Peng Y, Zhao S. Preparation and characterization of silica monolith modified with bovine serum albumin-gold nanoparticles conjugates and its use as chiral stationary phases for capillary electrochromatography. J Sep Sci 2011; 34:2329-36. [DOI: 10.1002/jssc.201100102] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2011] [Revised: 03/18/2011] [Accepted: 03/18/2011] [Indexed: 11/08/2022]
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9
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Monoliths with chiral surface functionalization for enantioselective capillary electrochromatography. J Pharm Biomed Anal 2010; 53:1091-123. [DOI: 10.1016/j.jpba.2010.05.026] [Citation(s) in RCA: 56] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2010] [Revised: 05/25/2010] [Accepted: 05/26/2010] [Indexed: 11/23/2022]
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10
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Chankvetadze B. Monolithic chiral stationary phases for liquid-phase enantioseparation techniques. J Sep Sci 2010; 33:305-14. [DOI: 10.1002/jssc.200900805] [Citation(s) in RCA: 58] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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11
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He C, Hendrickx A, Mangelings D, Smeyers-Verbeke J, Vander Heyden Y. Monolithic silica capillary columns with immobilized cellulose tris(3,5-dimethylphenylcarbamate) for enantiomer separations in CEC. Electrophoresis 2009; 30:3796-803. [DOI: 10.1002/elps.200900456] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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12
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Dong X, Wu R, Dong J, Wu M, Zhu Y, Zou H. Polyacrylamide-based monolithic capillary column with coating of cellulose tris(3,5-dimethylphenyl-carbamate) for enantiomer separation in capillary electrochromatography. Electrophoresis 2008; 29:919-27. [PMID: 18219649 DOI: 10.1002/elps.200700644] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
A hydrophilic chiral capillary monolithic column for enantiomer separation in CEC was prepared by coating cellulose tris(3,5-dimethylphenyl-carbamate) (CDMPC) on porous hydrophilic poly(acrylamide-co-N,N'-methylene-bisacrylamide) (poly(AA-co-MBA)) monolithic matrix with confine of a fused-silica capillary. The coating conditions were optimized to obtain a stable and reproducible chiral stationary phase for CEC. The effect of organic modifier of ACN in aqueous mobile phase for the enantiomer separation by CEC was investigated, and the significant influence of ACN on the enantioresolution and electrochromatographic retention was observed. Twelve pairs of enantiomers including acidic, neutral, and basic analytes were tested and nine pairs of them were baseline-enantioresolved with acidic and basic aqueous mobile phases. A good within-column repeatability in retention time (RSD = 2.4%) and resolution (RSD = 3.2%) was obtained by consecutive injections of a neutral compound, benzoin, on a prepared chiral monolithic column, while the between-column repeatability in retention time (RSD = 6.4%) and resolution (RSD = 9.6%) was observed by column-to-column examination. The prepared monolithic stationary phase showed good stability in either acidic or basic mobile phase.
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Affiliation(s)
- Xiaoli Dong
- Department of Chemistry, Xixi Campus, Zhejiang University, Hangzhou, P. R. China
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Preinerstorfer B, Hoffmann C, Lubda D, Lämmerhofer M, Lindner W. Enantioselective silica-based monoliths modified with a novel aminosulfonic acid-derived strong cation exchanger for electrically driven and pressure-driven capillary chromatography. Electrophoresis 2008; 29:1626-37. [DOI: 10.1002/elps.200700525] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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14
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Smith NW, Jiang Z. Developments in the use and fabrication of organic monolithic phases for use with high-performance liquid chromatography and capillary electrochromatography. J Chromatogr A 2008; 1184:416-40. [DOI: 10.1016/j.chroma.2007.09.027] [Citation(s) in RCA: 79] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2007] [Revised: 09/11/2007] [Accepted: 09/13/2007] [Indexed: 10/22/2022]
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15
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Qin F, Xie C, Yu Z, Kong L, Ye M, Zou H. Monolithic enantiomer-selective stationary phases for capillary electrochromatography. J Sep Sci 2007; 29:1332-43. [PMID: 16894777 DOI: 10.1002/jssc.200600030] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Monolithic materials have become a well-established format for stationary phases in the field of capillary electrochromatography. Four types of monoliths, namely particle-fixed, silica-based, polymer-based, and molecularly imprinted monoliths, have been utilized as enantiomer-selective stationary phases in CEC. This review summarizes recent developments in the area of monolithic enantiomer-selective stationary phases for CEC. The preparative procedure and the characterization of these columns are highlighted. In addition, the disadvantages and limitations of different monolithic enantiomer-selective stationary phases in CEC are briefly discussed.
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Affiliation(s)
- Feng Qin
- National Chromatographic Research & Analysis Center, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian, China
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16
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Dong X, Dong J, Ou J, Zhu Y, Zou H. Preparation and evaluation of a vancomycin-immobilized silica monolith as chiral stationary phase for CEC. Electrophoresis 2007; 28:2606-12. [PMID: 17592611 DOI: 10.1002/elps.200600605] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Enantiomeric separations in CEC with the macrocyclic antibiotic vancomycin immobilized silica monolith as a chiral stationary phase are presented. The monolithic silica capillary columns were prepared by a sol-gel process in fused-silica capillaries with an inner diameter of 50 mum and subsequently in situ immobilization of vancomycin as a chiral selector by reductive amination. Enantioselectivity was obtained for eight pairs of enantiomers in nonaqueous polar organic or aqueous mobile phases and most of them were baseline-separated with high column efficiencies. It was observed that the organic modifier ratio (MeOH/ACN) in the polar organic mobile phase played a significant role in controlling the resolution and efficiency of the enantiomers. In enantiomeric separation of propranolol, repeatability for column efficiency and resolution in the nonaqueous mobile phase was given in terms of RSD values at 1.1 and 2.3% (n = 5) for run-to-run injections and 7.2 and 9.6% (n = 5) for column-to-column testing while repeatability for the separation of thalidomide in the aqueous mobile phase was given in terms of RSD values at 1.5, 2.8% and 6.1, 10.5%, respectively.
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Affiliation(s)
- Xiaoli Dong
- Department of Chemistry, Xixi Campus, Zhejiang University, Hangzhou, P. R. China
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Schmid MG, Koidl J, Wank P, Kargl G, Zöhrer H, Gübitz G. Enantioseparation by ligand-exchange using particle-loaded monoliths: Capillary-LC versus capillary electrochromatography. ACTA ACUST UNITED AC 2007; 70:77-85. [PMID: 16978701 DOI: 10.1016/j.jbbm.2006.06.004] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2006] [Revised: 06/13/2006] [Accepted: 06/27/2006] [Indexed: 10/24/2022]
Abstract
Particle-loaded monoliths containing a polymethacrylamide backbone were prepared by suspending a silica-based chiral phase in the mixture of the monomers followed by in-situ polymerization in the capillary. As chiral selector l-4-hydroxyproline chemically bonded to 3 microm silica particles was used following the separation principle of ligand-exchange. Electrolytes containing Cu(II) ions were used. Amino acid enantiomers were separated by capillary-LC and CEC, whereby the latter showed the better resolution properties. For the chiral separation of alpha-hydroxy acids the EOF was reversed by copolymerizing diallyldimethylammonium chloride instead of vinylsulfonic acid as charge providing agent. Short columns of 6 cm were found to be sufficient in the case of CEC for baseline separations of amino acids with alpha values up to 5.
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Affiliation(s)
- Martin G Schmid
- Institute of Pharmaceutical Sciences, Department of Pharmaceutical Chemistry, Karl-Franzens-University, Universitätsplatz 1, A-8010 Graz, Austria.
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Wistuba D, Schurig V. Comparison of monolithic approaches for enantioselective capillary electrochromatography involving cyclodextrins. J Sep Sci 2006; 29:1344-52. [PMID: 16894778 DOI: 10.1002/jssc.200600114] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
The access to CD-modified monoliths for enantiomeric separation by CEC can be divided into two main approaches. (i) Silica-based monoliths, prepared by either a sol-gel process or by sintering of silica particles, are modified after fabrication by coating with a CD selector. Alternatively the fusion of CD functionalized silica particle via gluing is feasible. (ii) Rigid or homogeneous organic polymer-based monoliths, prepared by polymerization of organic monomers in the presence of a porogen, are modified with the CD selector either by copolymerization or by physical incorporation into the continuous bed.
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Affiliation(s)
- Dorothee Wistuba
- Institute of Organic Chemistry, University of Tübingen, Tübingen, Germany.
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Kitagawa F, Inoue K, Hasegawa T, Kamiya M, Okamoto Y, Kawase M, Otsuka K. Chiral separation of acidic drug components by open tubular electrochromatography using avidin immobilized capillaries. J Chromatogr A 2006; 1130:219-26. [PMID: 16600258 DOI: 10.1016/j.chroma.2006.03.077] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2006] [Revised: 03/17/2006] [Accepted: 03/22/2006] [Indexed: 10/24/2022]
Abstract
Avidin was immobilized covalently onto the inner surface of fused silica capillaries as a stationary phase in an open tubular capillary electrochromatography (OT-CEC) for chiral separations. The modification was attained by a combination of glutaraldehyde with both an amino-silylated fused silica surface and avidin using a Schiff base formation reaction. This method couples the advantage of high efficiency and small consumption of a chiral selector with the possibility of UV detection without limitations of protein absorption. In addition, the prepared capillary was stable for 50 days with over 100 runs. To evaluate the electrochromatographic performance of the prepared capillaries, the chiral separation of abscisic acid and arylpropionic acids were investigated. Effects of the modification condition of protein, pH of running buffer, and an organic modifier on the enantioseparation were also investigated. In addition, the avidin immobilized capillary was employed for the selective chiral analysis with an electrospray ionization mass spectrometry (ESI-MS) detection scheme.
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Affiliation(s)
- Fumihiko Kitagawa
- Department of Material Chemistry, Graduate School of Engineering, Kyoto University, Katsura, Kyoto 615-8510, Japan.
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Gatschelhofer C, Schmid MG, Schreiner K, Pieber TR, Sinner FM, Gübitz G. Enantioseparation of glycyl-dipeptides by CEC using particle-loaded monoliths prepared by ring-opening metathesis polymerization (ROMP). ACTA ACUST UNITED AC 2006; 69:67-77. [PMID: 16556463 DOI: 10.1016/j.jbbm.2006.01.010] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2005] [Accepted: 01/09/2006] [Indexed: 11/27/2022]
Abstract
Novel particle-loaded monolithic capillary electrochromatography (CEC) phases for chiral separations were prepared via ring-opening metathesis polymerization (ROMP) within the confines of fused silica columns with 200 microm i.d. using norborn-2-ene (NBE), 1,4,4a,5,8,8a-hexahydro-1,4,5,8,exo,endo-dimethanonaphthalene (DMN-H6) as monomers, 2-propanol and toluene as porogens, RuCl2(PCy3)2(CHPh) as initiator and silica-based particles containing the chiral selector. By suspending silica particles bearing the chiral selector in the polymerization mixture, particle-based monoliths are easily prepared. This approach has several advantages compared to particle-based separation media: (i) the concept of particle-based monoliths is broadly applicable, as any silica-based chiral phase can be used; (ii) they are inexpensive to prepare; and (iii) the manufacturing process is very simple, no sophisticated packing procedures or the preparation of end frits are required. To show the usefulness of this concept for chiral CEC, the chiral separation performance of particle-loaded CEC monoliths bearing teicoplanin aglycone, chemically bonded to 3 microm silica gel, was investigated for a set of glycyl-dipeptides. Particle-loaded ROMP CEC monoliths showed good separation performance for glycyl-dipeptides.
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Affiliation(s)
- Christina Gatschelhofer
- Institute of Medical Technologies and Health Management, JOANNEUM RESEARCH, Auenbruggerplatz 20/3, A-8036 Graz, Austria
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Preinerstorfer B, Lubda D, Lindner W, Lämmerhofer M. Monolithic silica-based capillary column with strong chiral cation-exchange type surface modification for enantioselective non-aqueous capillary electrochromatography. J Chromatogr A 2006; 1106:94-105. [PMID: 16388817 DOI: 10.1016/j.chroma.2005.12.039] [Citation(s) in RCA: 53] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2005] [Revised: 11/29/2005] [Accepted: 12/05/2005] [Indexed: 11/29/2022]
Abstract
A silica-based monolithic stationary phase prepared by the sol-gel process in a 100 microm I.D. fused-silica (FS) capillary has been modified chemically with 3-mercaptopropyl trimethoxysilane followed by immobilization of a strong cation-exchange (SCX) type chiral selector, (S)-N-(4-allyloxy-3,5-dichlorobenzoyl)-2-amino-3,3-dimethylbutane phosphonic acid, by radical addition reaction onto the reactive sulfhydryl surface. After a fine-tuning of the mobile phase composition, the enantioselective capillary column was evaluated for the separation of various chiral basic drugs by enantioselective non-aqueous capillary electrochromatography (CEC), in comparison to capillary column analogs packed with 3.5 microm silica particles having attached the same selector. The performance of the monolithic silica column was further compared to corresponding polymethacrylate-based organic polymer monoliths. The study indicated that strong counter-ions such as 2-aminobutanol or N,N,N',N'-tetramethylethylenediamine are needed, although they reduce the electroosmotic flow velocity and separation factors in comparison to less efficient counter-ions, in order to allow the elution of the oppositely charged solutes in the ion-exchange retention mode within reasonable run time and as sharp zones. In contrast, weak counter-ions such as N,N-diisopropylethylamine (Huenig base) provided stronger electroosmotic flow and much better separation factors, but relatively poor peak efficiencies. Overall, with the chemically functionalized monolithic silica column the high quality separations of packed column analogs could be approximated, with regards to both separation factors and peak performances. On the other hand, the monolithic capillary column certainly outperformed the packed column in terms of system robustness under capillary electrochromatography conditions and showed excellent column longevity. The enantioselective strong cation-exchange-type monolithic silica column performed also well in comparison to the organic polymer monolith.
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Affiliation(s)
- Beatrix Preinerstorfer
- Christian Doppler Laboratory for Molecular Recognition Materials, Department of Analytical and Food Chemistry, University of Vienna, Währinger Strasse 38, A-1090 Vienna, Austria
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Sułkowska A, Bojko B, Równicka J, Sułkowski WW. Competition of cytarabine and aspirin in binding to serum albumin in multidrug therapy. Biopolymers 2006; 81:464-72. [PMID: 16419075 DOI: 10.1002/bip.20445] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
The aim of this study was to describe a competition between cytarabine (araC) and aspirin (ASA) in binding with bovine serum albumin (BSA). High-affinity binding sites for both drugs were determined using a spectrofluorimetric method. Cytarabine as well as aspirin binds in the IIA hydrophobic subdomain of the transporting protein. Binding constants for araC-BSA and ASA-BSA were calculated by the Scatchard method. Analysis of ultraviolet (UV) difference spectra showed that araC, which has a higher affinity to BSA in comparison to ASA [Ka(araC) > Ka(ASA)] displaces ASA in high-affinity binding sites. The competition between drugs in low-affinity binding sites was investigated using (1)H nuclear magnetic resonance (NMR) and 13C-NMR spectra. We concluded that in the low-affinity binding sites cytarabine decreases the affinity of albumin toward aspirin. However, the interaction between araC and BSA becomes more difficult in the presence of aspirin.
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Affiliation(s)
- Anna Sułkowska
- Medical University of Silesia, Department of Physical Pharmacy, Jagiellońska 4, Sosnowiec, 41-200, Poland.
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Gübitz G, Schmid MG. Recent advances in chiral separation principles in capillary electrophoresis and capillary electrochromatography. Electrophoresis 2005; 25:3981-96. [PMID: 15597419 DOI: 10.1002/elps.200406173] [Citation(s) in RCA: 109] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
This review summarizes recent developments in chiral separation in capillary zone electrophoresis (CZE), electrokinetic chromatography (EKC), and capillary electrochromatography (CEC) covering literature published since the year 2000. New chiral selectors and innovative approaches for CE and CEC are introduced. Recent progress in column technology for CEC is highlighted and the development of new chiral stationary phases is discussed. This review is not dedicated to list applications but will focus on new developments.
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Affiliation(s)
- Gerald Gübitz
- Institute of Pharmaceutical Sciences, Dept. of Pharm. Chemistry, Karl-Franzens-University, Graz, Austria.
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Preinerstorfer B, Lindner W, Lämmerhofer M. Polymethacrylate-type monoliths functionalized with chiral amino phosphonic acid-derived strong cation exchange moieties for enantioselective nonaqueous capillary electrochromatography and investigation of the chemical composition of the monolithic polymer. Electrophoresis 2005; 26:2005-18. [PMID: 15812836 DOI: 10.1002/elps.200410380] [Citation(s) in RCA: 54] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
In situ prepared monolithic poly(glycidyl methacrylate-co-ethylene dimethacrylate) (poly(GMA-co-EDMA)) capillary columns were activated to reactive thiol-monoliths and subsequently functionalized with (S)-N-(4-allyloxy-3,5-dichlorobenzoyl)-2-amino-3,3-dimethylbutanephosphonic acid as chiral selector by radical addition to afford enantioselective strong cation exchanger (SCX) capillary columns (100 microm inner diameter (ID)). These monolithic capillaries were devised for the enantioseparation of chiral bases by nonaqueous and aqueous capillary electrochromatography (CEC) and the results obtained for mefloquine and its tert-butylcarbamate as test compounds were compared to those obtained with particulate silica-based analogs (packed columns). Despite abolishment of nonspecific ionic interactions between the cationic solutes and residual silanols that may diminish separation factors of the silica-based chiral SCX particles, the poly(GMA-co-EDMA)-supported SCX monolith did not, as expected, show better enantioselectivities, which was assumed to be due to detrimental nonspecific interactions between the analytes and the lipophilic polymer backbone. In order to minimize these unfavorable contributions, less lipophilic monoliths were developed by copolymerization of different amounts of the hydrophilic monomer 2-hydroxyethyl methacrylate (HEMA) with GMA and EDMA, leading to GMA-co-HEMA-co-EDMA-terpolymeric monoliths. By this increase of the hydrophilicity of the monolithic support the enantioselectivity of the resultant SCX stationary phase could be enhanced and reached values comparable to the packed silica-based enantioselective SCX capillaries. Additionally, the mobile phase composition and other variables were examined and it could be shown that the separation factors are considerably affected by diverse parameters such as acetonitrile-methanol ratio and type and concentration of the counterion. Mefloquine enantiomers could be separated with alpha-values up to 1.56 and a maximum plate count of ca. 60,000 m(-1) could be achieved.
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Affiliation(s)
- Beatrix Preinerstorfer
- Christian Doppler Laboratory for Molecular Recognition Materials, Institute of Analytical Chemistry, University of Vienna, A-1090 Vienna, Austria
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Bedair M, El Rassi Z. Recent advances in polymeric monolithic stationary phases for electrochromatography in capillaries and chips. Electrophoresis 2004; 25:4110-9. [PMID: 15597411 DOI: 10.1002/elps.200406136] [Citation(s) in RCA: 72] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
This review article summarizes the advances made over the last two years in polymeric monoliths for capillary electrochromatography (CEC). It covers the scientific literature in the period extending form the second half of 2002 until the end of first half of 2004. Currently, there is an increasing interest in monolithic stationary phases in CEC as an alternative to particulate packed capillary columns due in major part to the simplicity of the in situ preparation of monolithic stationary phases and the availability of a wide chemistry for surface ligands, which allow for tailoring the chromatographic sorbent needed for solving a given separation problem(s). The various approaches, formats, and chemistries used for the preparation of monolithic stationary phases are described.
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Affiliation(s)
- Mohamed Bedair
- Department of Chemistry, Oklahoma State University, Stillwater, OK 74078-3071, USA
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Affiliation(s)
- Timothy J Ward
- Department of Chemistry, Millsaps College, 1701 North State Street, Box 150306, Jackson, Mississippi 39210, USA.
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Maruska A, Kornysova O. Continuous beds (monoliths): stationary phases for liquid chromatography formed using the hydrophobic interaction-based phase separation mechanism. ACTA ACUST UNITED AC 2004; 59:1-48. [PMID: 15134905 DOI: 10.1016/j.jbbm.2003.12.003] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2003] [Revised: 12/09/2003] [Accepted: 12/09/2003] [Indexed: 01/10/2023]
Abstract
The pioneering research work published by Hjertén et al. [J. Chromatogr. 473 (1989) 273] in 1989 dealing with development and application of the continuous bed (monolithic) technique as an attractive alternative for the classical packed columns in chromatography, stimulated further investigations in this direction. The research data published since that time on the development and application of the continuous beds formed using hydrophobic interaction-based phase separation mechanism are reviewed. Some innovative species of the beds, such as polyrotaxane beds or nonparticulate restricted-access materials for direct analysis of the biological fluids in the capillary format are also discussed. Characteristic features and practical details of the continuous bed technique are revealed. Due to many advantages, the continuous bed technique became a competitor with the traditional packings in capillary or chip-based microanalysis. The importance of the continuous bed morphology on the chromatographic characteristics is shown. The applicability of modern microscopic analysis to evaluate the morphology of the continuous beds is demonstrated.
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Affiliation(s)
- Audrius Maruska
- Department of Chemistry, Vytautas Magnus University, Vileikos 8, LT-3035 Kaunas, Lithuania.
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