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Multiple biological activities and biosynthesis mechanisms of specific conjugated linoleic acid isomers and analytical methods for prospective application. Food Chem 2023; 409:135257. [PMID: 36584529 DOI: 10.1016/j.foodchem.2022.135257] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2022] [Revised: 11/27/2022] [Accepted: 12/18/2022] [Indexed: 12/30/2022]
Abstract
Conjugated linoleic acid (CLA) is a collective term for the octadecadienoic acid isomers containing conjugated double bonds. This article reviewed CLA isomers from biological activities, biosynthesis mechanisms and analytical methods. The biological activities of CLA isomers in anti-obesity, cardiovascular protection, diabetes management and anti-cancer in vitro and in vivo were mainly reviewed. More attention has been paid to the production of the specific CLA isomer due to its biological activity. The biosynthesis methods of CLA isomers, such as dietary modification in ruminants and fermentation by microorganisms & enzymes, were systematically introduced. A rapid, accurate and economic analysis method will promote the research in both biological activities and biosynthesis mechanisms of CLA isomers. The merits of UV spectrometry, GC, HPLC, MS and CE used in the analysis of CLA isomers were also compared in detail. This paper aims to put into perspective the current status and future trends on CLA isomers.
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Zhang H, Zhang W, Zhang Z, Shi Z, Liu W. GREEN ANALYTICAL METHOD FOR THE SENSITIVE DETERMINATION OF MONONITROPHENOL ISOMERS BY DYNAMIC pH JUNCTION CAPILLARY ELECTROPHORESIS. J LIQ CHROMATOGR R T 2014. [DOI: 10.1080/10826076.2013.778633] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Affiliation(s)
- Hongyi Zhang
- a College of Chemistry and Environmental Science, Hebei University , Baoding , China
- b Key Laboratory of Analytical Science and Technology of Hebei Province , Baoding , China
| | - Wei Zhang
- a College of Chemistry and Environmental Science, Hebei University , Baoding , China
| | - Zhijun Zhang
- a College of Chemistry and Environmental Science, Hebei University , Baoding , China
| | - Zhihong Shi
- a College of Chemistry and Environmental Science, Hebei University , Baoding , China
- b Key Laboratory of Analytical Science and Technology of Hebei Province , Baoding , China
| | - Wei Liu
- a College of Chemistry and Environmental Science, Hebei University , Baoding , China
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3
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Separation and determination of chlorophenylpiperazine isomers in confiscated pills by capillary electrophoresis. J Pharm Biomed Anal 2013; 84:140-7. [DOI: 10.1016/j.jpba.2013.05.042] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2013] [Revised: 05/26/2013] [Accepted: 05/27/2013] [Indexed: 11/18/2022]
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4
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Hefnawy MM, Stewart JT. ENANTIOSELECTIVE DETERMINATION OF R(+) AND S(−) ROGLETIMIDE IN SERUM USING ALPHA-CYCLODEXTRIN MODIFIED CAPILLARY ELECTROPHORESIS AND SOLID PHASE EXTRACTION. J LIQ CHROMATOGR R T 2006. [DOI: 10.1081/jlc-100101490] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Affiliation(s)
- Mohamed M. Hefnawy
- a Department of Medicinal Chemistry , College of Pharmacy, University of Georgia , Athens, GA, 30602-2352, U.S.A
| | - James T. Stewart
- a Department of Medicinal Chemistry , College of Pharmacy, University of Georgia , Athens, GA, 30602-2352, U.S.A
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Zhao T, Hu XB, Cheng JK, Lu XR. P-sulfonic Calix[4]Arene as Running Buffer Additive in Electrokinetic Chromatography. J LIQ CHROMATOGR R T 2006. [DOI: 10.1080/10826079808001261] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Affiliation(s)
- T. Zhao
- a Department of Chemistry , Wuhan University , Wuhan, 430072, China
| | - X.-B. Hu
- a Department of Chemistry , Wuhan University , Wuhan, 430072, China
| | - J.-K. Cheng
- a Department of Chemistry , Wuhan University , Wuhan, 430072, China
| | - X.-R. Lu
- a Department of Chemistry , Wuhan University , Wuhan, 430072, China
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Forlay-Frick P, Mangelings D, Iványi T, Lázár I, Héberger K, Vander Heyden Y. Newly synthesized tetraoxa-diaza crown ether derivatives versus commercialized crown ethers in the separation of positional isomers with capillary electrophoresis. J Pharm Biomed Anal 2006; 41:1164-70. [PMID: 16580807 DOI: 10.1016/j.jpba.2006.02.042] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2005] [Accepted: 02/16/2006] [Indexed: 11/15/2022]
Abstract
Three new tetraoxa-diaza derivatives of 1,4,10,13-tetraoxa-7,16-diazacyclo-octadecane (R-1, R-2 and R-3) and three commercially available crown ethers, 18-crown-6 (18C6), (+)-18-crown-6-tetracarboxilic acid (18C6H4) and 1,4,10,13-tetraoxa-7,16-diazacyclo-octadecane, were investigated to separate the positional isomers of aminophenol, aminobenzoic acid and aminocresol. The running electrolyte, in which the crown ethers were dissolved, was a 50 mM Tris solution adjusted to pH 2.0 with hydrochloric acid. Using 50 mM H3PO4 buffer, whose pH was adjusted to 2.0 with Tris, or only hydrochloric acid solution with the same pH, did not allow good separations for the tested components. The effect of the crown ether concentration on the separation of the 11 positional isomers was studied in the concentration range of 10-50 mM. The best separations were achieved using the 18C6 and the 18C6H4 crown ethers: 9 isomers out of 11 could be separated within one run. The m- and p-aminophenol isomers could not be separated under the investigated experimental conditions. The newly synthesized tetraoxa-diaza crown ether derivatives were only found suitable for the separation of aminobenzoic acid positional isomers. The macrocyclic ring of the tetraoxa-diaza crown ethers was not able to form a stable inclusion complex with the tested positional isomers. Consequently, the aminophenol and aminocresol isomers were not separated, the isomers migrated with the same or very similar velocities.
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Affiliation(s)
- Peter Forlay-Frick
- Department of Analytical Chemistry and Pharmaceutical Technology, Vrije Universiteit Brussel-VUB, Laarbeeklaan 103, 1090 Brussels, Belgium
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Fischer J, Barek J, Wang J. Separation and Detection of Nitrophenols at Capillary Electrophoresis Microchips with Amperometric Detection. ELECTROANAL 2006. [DOI: 10.1002/elan.200503393] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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8
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Liu X, Cao Y, Chen Y. Separation of conjugated linoleic acid isomers by cyclodextrin-modified micellar electrokinetic chromatography. J Chromatogr A 2005; 1095:197-200. [PMID: 16243343 DOI: 10.1016/j.chroma.2005.09.090] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2005] [Revised: 09/26/2005] [Accepted: 09/30/2005] [Indexed: 11/23/2022]
Abstract
A cyclodextrin-modified micellar electrokinetic chromatography (CD-MEKC) method was developed for separating conjugated linoleic acid (CLA) isomers. All the seven CLA isomers (9cis,11cis-CLA, 9cis,11trans-CLA, 9trans,11trans-CLA, 10trans,12cis-CLA, 11cis,13cis-CLA, 11cis,13trans-CLA and 11trans,13trans-CLA) were completely separated in the optimized conditions (4% (w/v) beta-cyclodextrin (beta-CD), 54 mM sodium dodecyl sulphate (SDS), 80 mM borate (pH 9.0), 8 M urea, 4% (v/v) ethanol, 30 kV and 15 degrees C). The CD-MEKC method was superior to the gas chromatographic (GC) and silver-ion high-performance liquid chromatographic (Ag(+)-HPLC) methods that were generally used in analyzing CLA isomers.
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Affiliation(s)
- Xiaohua Liu
- Sino-German Joint Research Institute, Nanchang University, China
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9
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Wei F, Liu SM, Xu L, Cheng GZ, Wu CT, Feng YQ. The formation of cucurbit[n]uril (n = 6, 7) complexes with amino compounds in aqueous formic acid studied by capillary electrophoresis. Electrophoresis 2005; 26:2214-24. [PMID: 15880553 DOI: 10.1002/elps.200410260] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
For analytes involved in dynamic equilibrium processes, capillary electrophoresis is a powerful method of determining binding constants. In this work, the complex formation between cucurbit[n]uril (CB[n] n = 6, 7) and some amino compounds was studied by capillary electrophoresis in aqueous formic acid (65% v/v). Four groups of positional and structural isomers (o, m, p-methylanilines; m, p-nitroanilines; benzidine and o-tolidine; alpha, beta-naphthylamines and 1,5-diaminonaphthalene) were selected as model compounds for study of their host-guest inclusion complexation. The interactions between CB[n] (n = 6, 7) and the model compounds were also investigated using a molecular modeling method. The results indicate that the interactions of the compounds with CB[n] (n = 6, 7) are strongly affected by the position of the substituent(s) on the aromatic ring and the ion-dipole interaction between guest molecule and CB. Furthermore, the type and the concentration of CBs on the separation and migration behavior of the amino compounds were also studied.
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Affiliation(s)
- Fang Wei
- Department of Chemistry, Wuhan University, Wuhan, PR China
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Elek J, Mangelings D, Iványi T, Lázár I, Heyden YV. Enantioselective capillary electrophoretic separation of tryptophane- and tyrosine-methylesters in a dual system with a tetra-oxadiaza-crown-ether derivative and a cyclodextrin. J Pharm Biomed Anal 2005; 38:601-8. [PMID: 15967287 DOI: 10.1016/j.jpba.2005.02.014] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2004] [Revised: 01/31/2005] [Accepted: 02/01/2005] [Indexed: 11/18/2022]
Abstract
Different dual selector systems containing a cyclodextrin derivative (methyl-beta-cyclodextrin and dimethyl-beta-cyclodextrin) and a new diaza-crown-ether derivative (N-[2-(1,4,10,13-tetraoxa-7,16-diazacyclooctadecan-7-yl)propanoyl]glycine) were studied in the enantioselective separation of tryptophan-methylester and tyrosine-methylester enantiomers. This paper deals with the systematic study of the effects of changing the composition of the background electrolyte on the resolution of the d- and l- forms using an experimental design approach. It was found that the dual systems allowed a better chiral separation of the amino acid derivatives. The experimental design approach also allowed improving the separation compared to the starting conditions (center point of the design), which were adopted from a previous study.
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Affiliation(s)
- János Elek
- Research Group of Homogeneous Catalysis Hungarian Academy of Sciences, University of Debrecen, P.O. Box 7, Debrecen H-4010, Hungary
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Iványi T, Pál K, Lázár I, Massart DL, Vander Heyden Y. Application of tetraoxadiaza-crown ether derivatives as chiral selector modifiers in capillary electrophoresis. J Chromatogr A 2004; 1028:325-32. [PMID: 14989486 DOI: 10.1016/j.chroma.2003.11.097] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
Two new diaza-crown ether derivatives (R-1, RS-1) have been synthesized from 1,4,10,13-tetraoxa-7,16-diazacyclooctadecane and tested as potential chiral selectors in capillary electrophoresis (CE) for the chiral separation of five amino acid derivatives. The individual use of the selectors did not lead to chiral differentiation. However, they enhanced the enantioselective effect of different cyclodextrins in dual selector systems. In this paper, we report the effect of different substituted diaza-crown ether derivatives on the separation results obtained in dual systems with cyclodextrins.
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Affiliation(s)
- Tímea Iványi
- Department of Inorganic and Analytical Chemistry, University of Debrecen, P.O. Box 21, H-4010 Debrecen, Hungary
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12
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Chen MH, Ding WH. Separation and migration behavior of positional and structural naphthalenesulfonate isomers by cyclodextrin-mediated capillary electrophoresis. J Chromatogr A 2004; 1033:167-72. [PMID: 15072302 DOI: 10.1016/j.chroma.2004.01.017] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The effects of the type of buffer system, buffer pH, the polarity of electrode, and both the type and the concentration of cyclodextrins (CDs) on the separation and migration behavior of seven positional and structural naphthalenesulfonate isomers in CD-mediated capillary electrophoresis were systematically investigated. The most effective separation conditions were to use 20 mM phosphate buffer with beta-CD at pH 3.0, while the polarity of the electrodes were reversed across the capillary. Under such conditions, these isomers can be separated in 10 min. The results also indicate that the interactions of naphthalenesulfonate derivatives with CDs are strongly affected by the position of the substituent(s) on the aromatic ring. The inclusion complex formation constants of these compounds were evaluated to improve our understanding of the interaction between the naphthalenesulfonate derivatives and CDs. Moreover, the formation constants of naphthalene-2-sulfonate to beta-CD agreed closely with the data in the literature obtained by a spectrophotometric method and by CE methods in various pH buffers.
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Affiliation(s)
- Mei-Hui Chen
- Department of Chemistry, National Central University, Chung-Li 32054, Taiwan, ROC
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Cigić IK, Guček M, Zupančič-Kralj L, Pihlar B. Separation of isomers of dienoic acids by electromigration techniques. J Sep Sci 2003. [DOI: 10.1002/jssc.200301425] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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14
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Schöftner R, Pfeifer A, Buchberger W. Development of a simple CZE method for the analysis of an industrial cationizing reagent and its hydrolysis products. J Sep Sci 2002. [DOI: 10.1002/1615-9314(20020601)25:8<507::aid-jssc507>3.0.co;2-#] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
| | - Angelika Pfeifer
- Institute for Chemical Technology of Organic Materials, University of Linz, Altenbergerstrasse 69, A‐4040 Linz, Austria
| | - Wolfgang Buchberger
- Department of Analytical Chemistry, University of Linz, Altenbergerstrasse 69, A‐4040 Linz, Austria; Fax: +43 732 2468 8679
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Wang Y, Zeng Z, Guan N, Cheng J. Sol-gel technique for the preparation of beta-cyclodextrin derivative stationary phase in open-tubular capillary electrochromatography. Electrophoresis 2001; 22:2167-72. [PMID: 11504048 DOI: 10.1002/1522-2683(20017)22:11<2167::aid-elps2167>3.0.co;2-n] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
A novel open-tubular capillary electrochromatography (OT-CEC) column coated with 2,6-dibutyl-beta-cyclodextrin (DB-beta-CD) was prepared using sol-gel technique. In the sol-gel approach, owing to the three-dimensional network of sol-gel and the strong chemical bond between the stationary phase and the surface of capillary columns, good chromatographic characteristics and unique selectivity in separating isomers were shown. We achieved high efficiencies of 5-14 x 10(4) plates/m for the isomeric nitrophenols using the sol-gel-derived DB-beta-CD columns. The migration time reproducibility of the separation of the isomeric nitrophenols was better than 2.2% over five runs and 4.5% from column to column. These sol-gel-coated DB-beta-CD columns have shown improved separations of isomeric aminophenols, isomeric dihydroxybenzenes and isomeric nitrophenols, in comparison with the sol-gel matrix capillary column. The influences of buffer pH and methanol solvent on separation were investigated. The chiral resolution of enantiomers such as ibuprofen and binaphthol was explored primarily.
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Affiliation(s)
- Y Wang
- Department of Chemistry, Wuhan University, China
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16
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Nhujak T, Goodall DM. Trace analysis of gamma-cyclodextrin in a sample of beta-cyclodextrin by capillary electrophoresis. J Chromatogr A 2001; 907:313-20. [PMID: 11217038 DOI: 10.1016/s0021-9673(00)01058-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
A new capillary electrophoretic method for trace analysis of gamma-cyclodextrin, gamma-CD, in a sample of beta-CD has been developed, building on our recent work in which the tetraphenylborate ion, Ph4B-, was found to bind to gamma-CD three orders of magnitude more strongly than to beta-CD. The method involves measurement of the change of net electrophoretic mobility of Ph4B- and its CD complexes in a background electrolyte containing a fixed concentration of beta-CD. Good linearity was found between 1/deltamu and 1/Cgamma where deltamu is the difference in the mobility of Ph4B- in the beta-CD solution at a given and at zero concentration of gamma-CD, and Cgamma the gamma-CD concentration. The limit of detection for gamma-CD in a beta-CD sample was found to be 0.020% (w/w), and high precision and accuracy were obtained.
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Affiliation(s)
- T Nhujak
- Department of Chemistry, University of York, UK
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17
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Larsen KL, Zimmermann W. Analysis and characterisation of cyclodextrins and their inclusion complexes by affinity capillary electrophoresis. J Chromatogr A 1999. [DOI: 10.1016/s0021-9673(99)00091-6] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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18
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Li J, Waldron KC. Estimation of the pH-independent binding constants of alanylphenylalanine and leucylphenylalanine stereoisomers with beta-cyclodextrin in the presence of urea. Electrophoresis 1999; 20:171-9. [PMID: 10065974 DOI: 10.1002/(sici)1522-2683(19990101)20:1<171::aid-elps171>3.0.co;2-6] [Citation(s) in RCA: 53] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
The separation of stereoisomers, particularly enantiomers, is important when their physiological activity differs. We have resolved the four stereoisomers each of alanylphenylalanine (Ala-Phe) and of leucylphenylalanine (Leu-Phe) by capillary electrophoresis using beta-cyclodextrin as a buffer additive and urea to enhance its solubility. A study of the influence of pH and beta-cyclodextrin concentration on the separations showed that weak inclusion complexes were formed between the dipeptides and chiral selector. It was found that pH could alter the migration order of enantiomers L-Ala-L-Phe and D-Ala-D-Phe, as well as L-Leu-L-Phe and D-Leu-D-Phe; however, there was no change in order for the other pairs of optical isomers. Electrophoretic mobility data were used to estimate the acid dissociation constants of the dipeptide isomers at pH < 7 with no chiral selector present. By varying the concentration of beta-cyclodextrin, the chiral selector, the binding constants of Ala-Phe and Leu-Phe optical isomers in their fully protonated and zwitterionic forms were estimated. For the four Ala-Phe stereoisomers, K = 42-66 M(-1) and 4-41 M(-1) for the cationic and zwitterionic forms, respectively. For the four Leu-Phe stereoisomers, K = 43-94 M(-1) and 1-28 M(-1) for the cationic and zwitterionic forms, respectively.
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Affiliation(s)
- J Li
- Institute for Biological Sciences, NRC, Ottawa, ON, Canada
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19
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Rathore AS, Horváth C. Cyclodextrins as selectivity enhancers in capillary zone electrophoresis of proteins. Electrophoresis 1998; 19:2285-9. [PMID: 9788310 DOI: 10.1002/elps.1150191306] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
The selectivity in the capillary zone electrophoresis (CZE) of a variety of acidic and basic proteins including alpha-chymotrypsinogen A, cytochrome c, lysozyme, ribonuclease A, ovalbumin, and beta-lactoglobulins A and B, was altered by adding 6-monodeoxy-6-monoamino-beta-cyclodextrin or carboxymethylated beta-cyclodextrin to the electrophoretic medium of aqueous 50 mM sodium phosphate, pH 2.5. On the other hand, no significant improvement was obtained in the separation upon addition of heptakis (2,6-di-O-methyl)-beta-cyclodextrin. Whereas protein adsorption on the wall of raw silica capillaries was significant in the absence of cyclodextrin, by addition of beta-cyclodextrin or its derivatives to the background electrolyte, wall adsorption was reduced with concomitant enhancement of the recovery. The results confirm that in various separation techniques, particularly those which employ microcolumns, certain cyclodextrin additives can be useful selectivity enhancers not only in the separation of small sample molecules but also in that of proteins.
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Affiliation(s)
- A S Rathore
- Department of Chemical Engineering, Yale University New Haven, CT 06520-8286, USA
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20
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Rovatti L, Curcuruto O, Hamdan M. Investigation of two geometric isomers by capillary zone electrophoresis with and without mass spectrometry detection. Forensic Sci Int 1998. [DOI: 10.1016/s0379-0738(98)00019-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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21
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Stathakis C, Cassidy RM. Control of relative migration of small inorganic and organic anions with cyclodextrins in capillary electrophoresis (CE). CAN J CHEM 1998. [DOI: 10.1139/v97-230] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The capillary electrophoretic separation of iodide, nitrate, perchlorate, thiocyanate, bromate, iodate, and ethane-, butane-, pentane-, and octanesulphonate was examined in sodium chromate or potassium hydrogen phthalate electrolytes and in the presence of α -, γ -, (0-40 mmol/L) and β -cyclodextrin (0-10 mmol/L). Largest decreases in electrophoretic mobility were observed for iodide, perchlorate, and thiocyanate, probably due to inclusion of these anions in the cyclodextrin (CD) cavity. Changes in migration patterns and electroosmotic flow were observed, which depended on cyclodextrin type and concentration and on electrolyte-cyclodextrin interactions. Thus for larger cavity cyclodextrins ( β-or γ-cyclodextrin) or in the presence of chromate, relatively small decreases in electrophoretic mobilities for all the anions were observed, indicating that a good match between analyte and cavity size and minimal cyclodextrin affinity for electrolyte ions are essential for different migration patterns. Separation efficiencies were between 50 000 and 400 000 theoretical plates, and calibration plots for iodide and octanesulphonate were linear; R2 = 0.998 and 0.9999, respectively, in the concentration range (5 x 10-5)-(5 x 10-3) mol/L.Key words: capillary electrophoresis, inorganic and organic anions, cyclodextrins, inclusion complex, electroosmotic flow control.
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22
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Zhao T, Hu X, Cheng J, Lu X. Use of calix[4]arene to separate positional isomers in capillary electrophoresis. Anal Chim Acta 1998. [DOI: 10.1016/s0003-2670(97)00613-2] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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23
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Vigh G, Sokolowski AD. Capillary electrophoretic separations of enantiomers using cyclodextrin-containing background electrolytes. Electrophoresis 1997; 18:2305-10. [PMID: 9456045 DOI: 10.1002/elps.1150181221] [Citation(s) in RCA: 84] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
The 1996 primary literature papers which deal with the separation of enantiomers using cyclodextrins are reviewed here. Though the majority of the papers still use the neutral native cyclodextrins or the neutral derivatized cyclodextrins as resolving agents, there was a significant increase in number of separations which relied on charged cyclodextrins, both weak electrolytes and strong electrolytes, as resolving agents. Also, there was an increase in the number of papers which reported binding constants and correlated them with other physical or chemical characteristics of the analytes. Several successful minor enantiomer determinations were presented, pushing the reliable quantitation levels below 0.1%. Work continued on the simultaneous use of neutral and charged cyclodextrins to improve separation selectivity or peak resolution.
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Affiliation(s)
- G Vigh
- Department of Chemistry, Texas A&M University, College Station 77843-3255, USA.
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24
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Ferguson PD, Goodall DM, Loran JS. Systematic approach to links between separations in capillary electrophoresis and liquid chromatography IV. Application of binding constant-retention factor relationship to the separation of 2-, 3- and 4-methylbenzoate anions using β-cyclodextrin as selector. J Chromatogr A 1997. [DOI: 10.1016/s0021-9673(97)00144-1] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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