51
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An Important Application of Pirkle Type π-Acidic Chiral Stationary Phases: Resolution of Polynuclear Aromatic Hydrocarbon Mixtures by Normal-Phase Conventional and Capillary HPLC. B KOREAN CHEM SOC 2009. [DOI: 10.5012/bkcs.2009.30.4.945] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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52
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Enantiomeric separation of acidic compounds by nano-liquid chromatography with methylated-β-cyclodextrin as a mobile phase additive. J Sep Sci 2009; 32:1696-703. [DOI: 10.1002/jssc.200800667] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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53
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Zhang Y, Wang J, Okamoto Y, Tokeshi M, Kaji N, Baba Y. Velocity Gap Theory Developed for Magnifying Resolutions without Changing Separation Mechanisms or Separation Lengths. Anal Chem 2009; 81:2745-50. [DOI: 10.1021/ac802671m] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Affiliation(s)
- Yong Zhang
- Department of Applied Chemistry, Graduate School of Engineering, MEXT Innovative Research Center for Preventive Medical Engineering, Health Technology Research Center, Plasma Nanotechnology Research Center, Nagoya University, Nagoya 464-8603, Japan, National Institute of Advanced Industrial Science and Technology (AIST) Hayashi-cho 2217-14, Takamatsu 761-0395, Japan, and Institute for Molecular Science, National Institutes of Natural Sciences, Okazaki, 444-8585, Japan
| | - Jun Wang
- Department of Applied Chemistry, Graduate School of Engineering, MEXT Innovative Research Center for Preventive Medical Engineering, Health Technology Research Center, Plasma Nanotechnology Research Center, Nagoya University, Nagoya 464-8603, Japan, National Institute of Advanced Industrial Science and Technology (AIST) Hayashi-cho 2217-14, Takamatsu 761-0395, Japan, and Institute for Molecular Science, National Institutes of Natural Sciences, Okazaki, 444-8585, Japan
| | - Yukihiro Okamoto
- Department of Applied Chemistry, Graduate School of Engineering, MEXT Innovative Research Center for Preventive Medical Engineering, Health Technology Research Center, Plasma Nanotechnology Research Center, Nagoya University, Nagoya 464-8603, Japan, National Institute of Advanced Industrial Science and Technology (AIST) Hayashi-cho 2217-14, Takamatsu 761-0395, Japan, and Institute for Molecular Science, National Institutes of Natural Sciences, Okazaki, 444-8585, Japan
| | - Manabu Tokeshi
- Department of Applied Chemistry, Graduate School of Engineering, MEXT Innovative Research Center for Preventive Medical Engineering, Health Technology Research Center, Plasma Nanotechnology Research Center, Nagoya University, Nagoya 464-8603, Japan, National Institute of Advanced Industrial Science and Technology (AIST) Hayashi-cho 2217-14, Takamatsu 761-0395, Japan, and Institute for Molecular Science, National Institutes of Natural Sciences, Okazaki, 444-8585, Japan
| | - Noritada Kaji
- Department of Applied Chemistry, Graduate School of Engineering, MEXT Innovative Research Center for Preventive Medical Engineering, Health Technology Research Center, Plasma Nanotechnology Research Center, Nagoya University, Nagoya 464-8603, Japan, National Institute of Advanced Industrial Science and Technology (AIST) Hayashi-cho 2217-14, Takamatsu 761-0395, Japan, and Institute for Molecular Science, National Institutes of Natural Sciences, Okazaki, 444-8585, Japan
| | - Yoshinobu Baba
- Department of Applied Chemistry, Graduate School of Engineering, MEXT Innovative Research Center for Preventive Medical Engineering, Health Technology Research Center, Plasma Nanotechnology Research Center, Nagoya University, Nagoya 464-8603, Japan, National Institute of Advanced Industrial Science and Technology (AIST) Hayashi-cho 2217-14, Takamatsu 761-0395, Japan, and Institute for Molecular Science, National Institutes of Natural Sciences, Okazaki, 444-8585, Japan
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54
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Huang L, Lin JM, Yu L, Xu L, Chen G. Improved simultaneous enantioseparation of β-agonists in CE using β-CD and ionic liquids. Electrophoresis 2009; 30:1030-6. [DOI: 10.1002/elps.200800483] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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55
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Sensitivity improvement by using contactless conductivity rather than indirect UV detection for the determination of enantiomeric purity of amines by CE. Electrophoresis 2009; 30:487-98. [DOI: 10.1002/elps.200800316] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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56
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WANG M, DING X, CHEN H, CHEN X. Enantioseparation of Palonosetron Hydrochloride by Capillary Zone Electrophoresis with High-concentration .BETA.-CD as Chiral Selector. ANAL SCI 2009; 25:1217-20. [DOI: 10.2116/analsci.25.1217] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Affiliation(s)
- Min WANG
- Department of Chemistry, Lanzhou University
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57
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Kim K, Banerjee M, Yoon M, Das S. Chiral Metal-Organic Porous Materials: Synthetic Strategies and Applications in Chiral Separation and Catalysis. Top Curr Chem (Cham) 2009; 293:115-53. [DOI: 10.1007/128_2009_7] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
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58
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Takano Y, Chikaraishi Y, Ogawa NO, Kitazato H, Ohkouchi N. Compound-Specific Nitrogen Isotope Analysis of d-Alanine, l-Alanine, and Valine: Application of Diastereomer Separation to δ15N and Microbial Peptidoglycan Studies. Anal Chem 2008; 81:394-9. [DOI: 10.1021/ac802077v] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Yoshinori Takano
- Institute for Research on Earth Evolution (IFREE), Japan Agency for Marine-Earth Science and Technology (JAMSTEC), 2-15 Natsushima-cho, Yokosuka 237-0061, Japan
| | - Yoshito Chikaraishi
- Institute for Research on Earth Evolution (IFREE), Japan Agency for Marine-Earth Science and Technology (JAMSTEC), 2-15 Natsushima-cho, Yokosuka 237-0061, Japan
| | - Nanako O. Ogawa
- Institute for Research on Earth Evolution (IFREE), Japan Agency for Marine-Earth Science and Technology (JAMSTEC), 2-15 Natsushima-cho, Yokosuka 237-0061, Japan
| | - Hiroshi Kitazato
- Institute for Research on Earth Evolution (IFREE), Japan Agency for Marine-Earth Science and Technology (JAMSTEC), 2-15 Natsushima-cho, Yokosuka 237-0061, Japan
| | - Naohiko Ohkouchi
- Institute for Research on Earth Evolution (IFREE), Japan Agency for Marine-Earth Science and Technology (JAMSTEC), 2-15 Natsushima-cho, Yokosuka 237-0061, Japan
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59
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El Deeb S, Hasemann P, Wätzig H. Strategies in method development to quantify enantiomeric impurities using CE. Electrophoresis 2008; 29:3552-62. [PMID: 18803216 DOI: 10.1002/elps.200800081] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
The growing number of chiral new drug substances requires increasing efforts in developing enantioselective methods. According to International conference on Harmonization guidelines, one should quantify the enantiomeric impurity of 0.1% relative to the major constituent. Capillary electrophoresis has evolved into an important tool for the separation of chiral drugs. The common strategies consist of two steps: firstly, initial separation conditions are evaluated. This screening usually focuses on the selection of the appropriate chiral selector. In our study 22 neutral, anionic or cationic cyclodextrins were dissolved in phosphate buffer (pH 2.5, 50 mM, CD conc.: 2.0%). Then they were investigated for the separation of 14 chiral compounds. Secondly, the obtained initial conditions for the enantiomeric separation were optimized in terms of resolution and analysis time. In our approach, important optimized factors including the concentration of the chiral selector (1-10%), the pH of the buffer (2.0-9.0), and the percentage of organic modifier (0-15%) were studied. This common strategy was completed by elaborating final requirements for the quantification of the enantiomeric impurity. A resolution between 3 and 4 was found to be necessary for the racemic mixture during the screening and optimization steps, in order to later allow for peak overloading and thus to sufficiently increase the signal-to-noise ratio. The complete strategy was conducted for atenolol, isoprenaline, verapamil and mandelic acid.
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Affiliation(s)
- Sami El Deeb
- Department of Pharmaceutical Chemistry, Al-Azhar University-Gaza, Gaza, Palestinian Territory
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60
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Danger G, Ross D. Chiral separation with gradient elution isotachophoresis for futurein situextraterrestrial analysis. Electrophoresis 2008; 29:4036-44. [DOI: 10.1002/elps.200700950] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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61
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Tran CD, Mejac I. Chiral ionic liquids for enantioseparation of pharmaceutical products by capillary electrophoresis. J Chromatogr A 2008; 1204:204-9. [DOI: 10.1016/j.chroma.2008.04.013] [Citation(s) in RCA: 80] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2007] [Revised: 02/26/2008] [Accepted: 04/08/2008] [Indexed: 11/16/2022]
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62
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Zhang XH, Wang Y, Jin WJ. Enantiomeric discrimination of 1,1′-binaphthol by room temperature phosphorimetry using γ-cyclodextrin as chiral selector. Anal Chim Acta 2008; 622:157-62. [DOI: 10.1016/j.aca.2008.05.047] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2008] [Revised: 05/18/2008] [Accepted: 05/22/2008] [Indexed: 11/15/2022]
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63
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Tano C, Son SH, Furukawa JI, Furuike T, Sakairi N. Dodecyl thioglycopyranoside sulfates: Novel sugar-based surfactants for enantiomeric separations by micellar electrokinetic capillary chromatography. Electrophoresis 2008; 29:2869-75. [DOI: 10.1002/elps.200800045] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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64
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Yang J, Guan J, Pan L, Jiang K, Cheng M, Li F. Enantioseparation and impurity determination of the enantiomers of novel phenylethanolamine derivatives by high performance liquid chromatography on amylose stationary phase. Anal Chim Acta 2008; 610:263-7. [DOI: 10.1016/j.aca.2008.01.027] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2007] [Revised: 01/10/2008] [Accepted: 01/11/2008] [Indexed: 10/22/2022]
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65
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Wang HF, Zhu YZ, Lin JP, Yan XP. Fabrication of molecularly imprinted hybrid monolithsvia a room temperature ionic liquid-mediated nonhydrolytic sol–gel route for chiral separation of zolmitriptan by capillary electrochromatography. Electrophoresis 2008; 29:952-9. [DOI: 10.1002/elps.200700402] [Citation(s) in RCA: 72] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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66
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Inagaki S, Min JZ, Toyo'oka T. Prediction for the separation efficiency of a pair of enantiomers during chiral high-performance liquid chromatography using a quartz crystal microbalance. Anal Chem 2008; 80:1824-8. [PMID: 18215020 DOI: 10.1021/ac702031b] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
A simple and rapid screening method of the chiral stationary phase during high-performance liquid chromatography (HPLC) utilizing a quartz crystal microbalance (QCM) has been developed for the chiral separation of a pair of enantiomers. The outline of the method is as follows: a self-assembled monolayer (SAM) is constructed on the gold electrodes of the QCM sensor chips by utilizing the interaction between thiols and gold. The chiral selectors used as chiral stationary phases in the HPLC are then immobilized, and a pseudostationary phase is constructed on the electrodes. Subsequently, the sensors are equilibrated in the solutions, the targeted chiral samples are injected, and the frequency changes are observed. Four kinds of chiral molecules and three kinds of chiral stationary phases were examined in this study. When chiral separation is possible using the chiral stationary phase immobilized on the sensors, significant differences in the frequency changes are observed because the intensities based on interactions differ among the isomers. The developed method can predict not only the possibility for chiral separation but also the elution order from the chiral stationary phase column. Furthermore, the degree of the mutual separation of a pair of enantiomers seems to be roughly predictable from the difference in the frequency change (DeltaF) and first-order association rate constant (k(obs)). The method does not require several different kinds of chiral columns that are more expensive than achiral ones such as the octadecylsilica (ODS) column. The required amounts of the chiral stationary phases are extremely small, and the sensors with immobilized chiral selectors are reusable. In addition, the method requires only a few minutes to complete the analysis. Thus, considerable reductions in both cost and time are realized. By applying the developed method to many chiral molecules and chiral stationary phases, its superiority may be corroborated; thus, it is expected that the method can be effectively used for the selection of chiral stationary phases.
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Affiliation(s)
- Shinsuke Inagaki
- Division of Bio-Analytical Chemistry, School of Pharmaceutical Sciences, and Global COE Program, University of Shizuoka, 52-1 Yada, Suruga-ku, Shizuoka 422-8526, Japan
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67
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Abstract
The article brings a comprehensive survey of recent developments and applications of high-performance capillary electromigration methods, zone electrophoresis, ITP, IEF, affinity electrophoresis, EKC, and electrochromatography, to analysis, preparation, and physicochemical characterization of peptides. New approaches to the theoretical description and experimental verification of electromigration behavior of peptides and to methodology of their separations, such as sample preparation, adsorption suppression, and detection, are presented. Novel developments in individual CE and CEC modes are shown and several types of their applications to peptide analysis are presented: conventional qualitative and quantitative analysis, purity control, determination in biomatrices, monitoring of chemical and enzymatical reactions and physical changes, amino acid and sequence analysis, and peptide mapping of proteins. Some examples of micropreparative peptide separations are given and capabilities of CE and CEC techniques to provide important physicochemical characteristics of peptides are demonstrated.
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Affiliation(s)
- Václav Kasicka
- Institute of Organic Chemistry and Biochemistry, Academy of Sciences of the Czech Republic, Prague, Czech Republic.
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68
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Bao Y, Huang J, Li T, Armstrong DW. Evaluation of Pentaproline-Based Chiral Stationary Phase by LC. Chromatographia 2007. [DOI: 10.1365/s10337-007-0438-9] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
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69
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Tang W, Ng SC. Synthesis of cationic single-isomer cyclodextrins for the chiral separation of amino acids and anionic pharmaceuticals. Nat Protoc 2007; 2:3195-200. [DOI: 10.1038/nprot.2007.479] [Citation(s) in RCA: 53] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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70
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Badaloni E, Cabri W, Ciogli A, Deias R, Gasparrini F, Giorgi F, Vigevani A, Villani C. Combination of HPLC “Inverted Chirality Columns Approach” and MS/MS Detection for Extreme Enantiomeric Excess Determination Even in Absence of Reference Samples. Application to Camptothecin Derivatives. Anal Chem 2007; 79:6013-9. [PMID: 17602501 DOI: 10.1021/ac070776j] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
An original, extremely sensitive and selective HPLC-MS/MS technique for the identification and determination of the minor enantiomer in nonracemic mixtures, even when only one enantiomer is available as reference, is described. The method is based on the so-called "inverted chirality columns approach" (ICCA) and consists of the use of chiral stationary phases (CSPs) available in both enantiomeric forms: in fact, inversion of the elution order for a pair of enantiomers is observed in response to the change in column chirality. This offers two key advantages: first, it is possible to demonstrate the potential enantioselectivity of the system by generating a virtual racemate, and second, it permits the choosing of the right column chirality for trace determination. Combination with MS/MS detection affords high specificity allowing not only high sensitivity (down to 0.0025% of the minor enantiomer) but also unequivocal peak identification in complex mixtures. Applications to semisynthetic derivatives of camptothecin, endowed with antitumor activity, are reported. Moreover, applicability of ICCA is not limited to this class of molecules but generates universal support. Its use might also be extended to other classes of compounds by using other CSPs, available in both enantiomeric forms.
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Affiliation(s)
- Elena Badaloni
- Analytical Chemistry Department, R&D, Sigma-Tau S.p.A., Via Pontina Km 30.400, 00040 Pomezia, Rome, Italy
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71
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Kahle KA, Foley JP. Two-chiral component microemulsion EKC – chiral surfactant and chiral oil. Part 2: Diethyl tartrate. Electrophoresis 2007; 28:2644-57. [PMID: 17597467 DOI: 10.1002/elps.200600747] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
In this second study on dual-chirality microemulsions containing a chiral surfactant and a chiral oil, a less hydrophobic and lower interfacial tension chiral oil, diethyl tartrate, is employed (Part 1, Foley, J. P. et al.., Electrophoresis, DOI: 10.1002/elps.200600551). Six stereochemical combinations of dodecoxycarbonylvaline (DDCV: R, S, or racemic, 2.00% w/v), racemic 2-hexanol (1.65% v/v), and diethyl tartrate (D, L, or racemic, 0.88% v/v) were examined as pseudostationary phases (PSPs) for the enantioseparation of six chiral pharmaceutical compounds: pseudoephedrine, ephedrine, N-methyl ephedrine, metoprolol, synephrine, and atenolol. Average efficiencies increased with the addition of a chiral oil to R-DDCV PSP formulations. Modest improvements in resolution and enantioselectivity (alpha(enant)) were achieved with two-chiral-component systems over the one-chiral-component microemulsion. Slight enantioselective synergies were confirmed using a thermodynamic model. Results obtained in this study are compared to those obtained in Part 1 as well as those obtained with chiral MEEKC using an achiral, low-interfacial-tension oil (ethyl acetate). Dual-chirality microemulsions with the more hydrophobic oil dibutyl tartrate yielded, relative to diethyl tartrate, higher efficiencies (100,000-134,000 vs. 80,800-94,300), but lower resolution (1.64-1.91 vs. 2.08-2.21) due to lower enantioselectivities (1.060-1.067 vs. 1.078-1.081). Atenolol enantiomers could not be separated with the dibutyl tartrate-based microemulsions but were partially resolved using diethyl tartrate microemulsions. A comparable single-chirality microemulsion based on the achiral oil ethyl acetate yielded, relative to diethyl tartrate, lower efficiency (78 300 vs. 91 600), higher resolution (1.99 vs. 1.83), and similar enantioselectivities.
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Affiliation(s)
- Kimberly A Kahle
- Department of Chemistry, Drexel University, Philadelphia, PA 19104, USA
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72
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Kahle KA, Foley JP. Review of aqueous chiral electrokinetic chromatography (EKC) with an emphasis on chiral microemulsion EKC. Electrophoresis 2007; 28:2503-26. [PMID: 17657766 DOI: 10.1002/elps.200600808] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
The separation of enantiomers using electrokinetic chromatography (EKC) with chiral microemulsions is comprehensively reviewed through December 1, 2006. Aqueous chiral EKC separations based on other pseudostationary phases such as micelles and vesicles or on other chiral selectors such as CDs, crown ethers, glycopeptides, ligand exchange moeities are also reviewed from both mechanistic and applications perspective for the period of January 2005 to December 1, 2006.
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Affiliation(s)
- Kimberly A Kahle
- Department of Chemistry, Drexel University, Philadelphia, PA 19104, USA
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73
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Wang Z, Wang J, Hu Z, Kang J. Enantioseparation by CE with vancomycin as chiral selector: Improving the separation performance by dynamic coating of the capillary with poly(dimethylacrylamide). Electrophoresis 2007; 28:938-43. [PMID: 17309047 DOI: 10.1002/elps.200600514] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
An approach for improving the separation performance of the enantioseparation by CE with vancomycin as chiral selector is described. In the present method, a solution of poly(dimethylacrylamide) (PDMA) was used for dynamic coating of the capillary wall to minimize the adsorption of vancomycin onto the capillary wall, and to depress the EOF. Compared with the bare fused-silica capillaries and the capillaries coated with the polycationic polymer hexadimethrine bromide (HDB), the PDMA-coated capillary displayed the best separation performance. The resulting coating could withstand hundreds of runs without losing its function. Moreover, a partial filling technique was applied to avoid interference in detection caused by the presence of vancomycin in the buffer. The separation time was shortened when a short-end-injection technique was applied. Several parameters such as buffer pH, vancomycin concentration and plug length of the vancomycin solution for the separation were optimized. Under the optimal conditions, all tested enantiomers, including FMOC amino acids derivatives, ketoprofen and fenoprofen, were baseline-separated in less than 4.2 min.
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Affiliation(s)
- Zhaoyan Wang
- College of Chemistry and Chemical Engineering, Lanzhou University, Lanzhou, China
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74
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Doménech A, Alarcón J. Microheterogeneous Electrocatalytic Chiral Recognition at Monoclinic Vanadium-Doped Zirconias: Enantioselective Detection of Glucose. Anal Chem 2007; 79:6742-51. [PMID: 17655201 DOI: 10.1021/ac070623w] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Synthetic tetragonal and monoclinic vanadium-doped zirconias (t- and m-VxZr1-xO2, 0.005 < x < 0.150) exert an effective catalytic effect toward the electrochemical oxidation of glucose in aqueous alkaline media. The catalytic effect of monoclinic specimens attached to carbon and fluorine-doped tin oxide electrodes exhibits a remarkable enantioselectivity, so that catalytic currents for the oxidation of L-glucose at +0.92 V vs AgCl/Ag are considerably larger than those obtained for the oxidation of D-glucose. This enantioselectivity can be associated with the existence of a noncentrosymmetric coordination of vanadium centers in the monoclinic crystalline form of zirconia. From the electrochemical results, it can be suggested that the electrocatalytic mechanism includes the formation of glucose-vanadium surface adducts and electron transfer between catalytic centers and the substrate. The interference from chloride ions in the electrocatalytic process is significantly decreased by covering the zirconia particles with a layer of amorphous silica. These results propose that incorporation of catalytically active centers into nonsentrosymmetric sites of inorganic crystalline materials can be taken as a plausible strategy for chiral recognition via electrocatalysis.
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Affiliation(s)
- Antonio Doménech
- Departament de Química Analítica, Facultat de Química, Facultat de Química, Universitat de València, Doctor Moliner 50, 46100, Burjassot, Valencia, Spain.
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75
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Resolution of Three Important π-Basic Chiral Compounds on Recently Developed Five π-Acidic Chiral Columns. B KOREAN CHEM SOC 2007. [DOI: 10.5012/bkcs.2007.28.6.1042] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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76
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Chen X, Okamoto Y, Yano T, Otsuki J. Direct enantiomeric separations of tris(2-phenylpyridine) iridium (III) complexes on polysaccharide derivative-based chiral stationary phases. J Sep Sci 2007; 30:713-6. [PMID: 17461111 DOI: 10.1002/jssc.200600409] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
A convenient method is presented for the first time for the direct separation of enantiomers of a tris(2-phenylpyridine) iridium (III) and an analog substituted with long alkoxy chains on polysaccharide derivative-based chiral stationary phases by HPLC. Tris(2-phenylpyridine) iridium (III) was separated on the immobilized amylose 3,5-dimethylphenylcarbamate (Chiralpak IA) using hexane/CHCl3/CH2Cl2 (75:20:5) as an eluent, and the analog could be separated on the coated cellulose 3,5-dimethyl-phenylcarbamate (Chiralcel OD) and cellulose 4-methylbenzoate (Chiralcel OJ) using hexane/2-propanol (96:4) as the eluent. CD spectra of the eluted HPLC fractions were also recorded, and the observed mirror image patterns confirm their enantioseparations.
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Affiliation(s)
- Xiaoming Chen
- EcoTopia Science Institute, Nagoya University, Furo-cho, Chikusa-ku, Nagoya, Japan
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77
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Chu BL, Guo B, Zuo H, Wang Z, Lin JM. Simultaneous enantioseparation of antiparkinsonian medication Rotigotine and related chiral impurities by capillary zone electrophoresis using dual cyclodextrin system. J Pharm Biomed Anal 2007; 46:854-9. [PMID: 17383843 DOI: 10.1016/j.jpba.2007.02.010] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/01/2007] [Revised: 02/05/2007] [Accepted: 02/08/2007] [Indexed: 02/08/2023]
Abstract
A dual cyclodextrin (CD) system consisting of sulfated beta-CD (S-beta-CD) and methyl-beta-CD (M-beta-CD) modified capillary zone electrophoresis (CZE) method was proposed to separate the antiparkinsonian drug Rotigotine ((-)-(S)-2-(N-propyl-N-2-thienylethylamino)-5-hydroxytetralin) and related chiral impurities (2-(N-propylamino)-5-hydroxytetralin, 2-(N-propylamino)-5-methoxytetralin). The method was optimized by varying the CD type, the buffer pH, individual CD concentration of the dual system and the ionic strength of background electrolyte. Under the optimum conditions, i.e. 2% (w/v) S-beta-CD and 2% (w/v) M-beta-CD in 100mM sodium phosphate (pH 2.5) as the running buffer, separation voltage -20 kV, detected at 200 nm and temperature controlled at 20 degrees C, a satisfactory separation of the six analytes was accomplished. The optimized method was validated for specificity, precision, linearity, accuracy and stability using sodium benzenesulfonate as the internal standard. The relative standard deviation for migration time was less than 0.58%, and 3.78% for peak area ratio. The linearity ranged from 0.005 to 0.25 mM. The recovery ranged from 95.9% to 108.3%. The limits of detection and limits of quantification for each enantiomer were 0.003 and 0.01 mM, respectively. This method was utilized for evaluating the chiral purity of five batches of Rotigotine.
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Affiliation(s)
- Bao-Lin Chu
- State Key Laboratory of Chemical Resource Engineering, College of Science, Beijing University of Chemical Technology, Beijing 100029, China
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