1
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Wang Y, Li L, Sutton AT, Tu Q, Zhao K, Wen E, Osborn J, Singh A, Gunsch MJ, Rustandi RR, Foley D, He Y. Development of a capillary zone electrophoresis method to monitor magnesium ion consumption during in vitro transcription for mRNA production. Anal Bioanal Chem 2024:10.1007/s00216-024-05242-8. [PMID: 38594392 DOI: 10.1007/s00216-024-05242-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2023] [Revised: 03/01/2024] [Accepted: 03/05/2024] [Indexed: 04/11/2024]
Abstract
Messenger RNA (mRNA) vaccines represent a landmark in vaccinology, especially with their success in COVID-19 vaccines, which have shown great promise for future vaccine development and disease prevention. As a platform technology, synthetic mRNA can be produced with high fidelity using in vitro transcription (IVT). Magnesium plays a vital role in the IVT process, facilitating the phosphodiester bond formation between adjacent nucleotides and ensuring accurate transcription to produce high-quality mRNA. The development of the IVT process has prompted key inquiries about in-process characterization of magnesium ion (Mg++) consumption, relating to the RNA polymerase (RNAP) activation, fed-batch mode production yield, and mRNA quality. Hence, it becomes crucial to monitor the free Mg++ concentration throughout the IVT process. However, no free Mg++ analysis method has been reported for complex IVT reactions. Here we report a robust capillary zone electrophoresis (CZE) method with indirect UV detection. The assay allows accurate quantitation of free Mg++ for the complex IVT reaction where it is essential to preserve IVT samples in their native-like state during analysis to avoid dissociation of bound Mg complexes. By applying this CZE method, the relationships between free Mg++ concentration, the mRNA yield, and dsRNA impurity level were investigated. Such mechanistic understanding facilitates informed decisions regarding the quantity and timing of feeding starting materials to increase the yield. Furthermore, this approach can serve as a platform method for analyzing the free Mg++ in complex sample matrices where preserving the native-like state of Mg++ binding is key for accurate quantitation.
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Affiliation(s)
- Ying Wang
- Analytical Research and Development, Merck & Co., Inc., Rahway, NJ, 07065, USA.
| | - Li Li
- Analytical Research and Development, Merck & Co., Inc., Rahway, NJ, 07065, USA.
| | - Adam T Sutton
- Analytical Research and Development, Merck & Co., Inc., Rahway, NJ, 07065, USA
| | - Qiang Tu
- Analytical Research and Development, Merck & Co., Inc., Rahway, NJ, 07065, USA
| | - Kaixi Zhao
- Process Research and Development, Merck & Co., Inc., Rahway, NJ, 07065, USA
| | - Emily Wen
- Process Research and Development, Merck & Co., Inc., Rahway, NJ, 07065, USA
| | - James Osborn
- Process Research and Development, Merck & Co., Inc., Rahway, NJ, 07065, USA
| | - Andrew Singh
- Analytical Research and Development, Merck & Co., Inc., Rahway, NJ, 07065, USA
| | - Matthew J Gunsch
- Analytical Research and Development, Merck & Co., Inc., Rahway, NJ, 07065, USA
| | | | - David Foley
- Analytical Research and Development, Merck & Co., Inc., Rahway, NJ, 07065, USA
| | - Yu He
- Analytical Research and Development, Merck & Co., Inc., Rahway, NJ, 07065, USA
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Hu LF, Yin SJ, Zhang H, Yang FQ. Recent developments of monolithic and open-tubular capillary electrochromatography (2017-2019). J Sep Sci 2020; 43:1942-1966. [PMID: 31909566 DOI: 10.1002/jssc.201901168] [Citation(s) in RCA: 30] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2019] [Revised: 12/26/2019] [Accepted: 12/28/2019] [Indexed: 12/21/2022]
Abstract
Capillary electrochromatography, which combined the high selectivity of high-performance liquid chromatography and the high separation efficiency of capillary electrophoresis, is an attractive separation tool. In this review, the developments on monolithic and open tubular capillary electrochromatography during 2017 to August 2019 are summarized. Considering the development of novel stationary phases is the most active research field in capillary electrochromatography, monolithic capillary electrochromatography is classified according to the polymer-based and hybrid monolithic columns, while open-tubular capillary electrochromatography is categorized by cyclodextrin, silica, polymer, nanomaterials, microporous materials, and biomaterials-based open tubular columns.
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Affiliation(s)
- Lin-Feng Hu
- Chongqing Key Laboratory of Medicinal Resources in the Three Gorges Reservoir Region, School of Biological and Chemical Engineering, Chongqing University of Education, Chongqing, P.R. China
| | - Shi-Jun Yin
- School of Chemistry and Chemical Engineering, Chongqing University, Chongqing, P.R. China
| | - Hao Zhang
- School of Chemistry and Chemical Engineering, Chongqing University, Chongqing, P.R. China
| | - Feng-Qing Yang
- School of Chemistry and Chemical Engineering, Chongqing University, Chongqing, P.R. China
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3
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Mao Z, Qin X, Chen Z. Monolithic column functionalized with quinine derivative for anion‐exchange capillary electrochromatography. Electrophoresis 2018; 39:3006-3012. [DOI: 10.1002/elps.201800253] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2018] [Revised: 07/24/2018] [Accepted: 07/26/2018] [Indexed: 12/27/2022]
Affiliation(s)
- Zhenkun Mao
- Key Laboratory of Combinatorial Biosynthesis and Drug Discovery, Ministry of EducationWuhan University School of Pharmaceutical Sciences Wuhan P. R. China
| | - Xiaoning Qin
- Key Laboratory of Combinatorial Biosynthesis and Drug Discovery, Ministry of EducationWuhan University School of Pharmaceutical Sciences Wuhan P. R. China
| | - Zilin Chen
- Key Laboratory of Combinatorial Biosynthesis and Drug Discovery, Ministry of EducationWuhan University School of Pharmaceutical Sciences Wuhan P. R. China
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Takeda Y, Hayashi Y, Utamura N, Takamoto C, Kinoshita M, Yamamoto S, Hayakawa T, Suzuki S. Capillary electrochromatography using monoamine- and triamine-bonded silica nanoparticles as pseudostationary phases. J Chromatogr A 2016; 1427:170-6. [DOI: 10.1016/j.chroma.2015.11.085] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2015] [Revised: 11/24/2015] [Accepted: 11/26/2015] [Indexed: 11/30/2022]
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5
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Histidine-modified organic-silica hybrid monolithic column for mixed-mode per aqueous and ion-exchange capillary electrochromatography. J Sep Sci 2015; 38:2046-52. [DOI: 10.1002/jssc.201500115] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2015] [Revised: 03/28/2015] [Accepted: 03/30/2015] [Indexed: 01/04/2023]
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6
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Huang D, Yang Q, Jin S, Deng Q, Zhou P. Self-assembly of cellulose nanoparticles as electrolyte additive for capillary electrophoresis separation. J Chromatogr A 2014; 1367:148-53. [DOI: 10.1016/j.chroma.2014.09.032] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2014] [Revised: 09/11/2014] [Accepted: 09/14/2014] [Indexed: 12/30/2022]
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7
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Vinylbenzyl quaternary ammonium-based polymeric monolith with hydrophilic interaction/strong anion exchange mixed-mode for pressurized capillary electrochromatography. J Chromatogr A 2013; 1316:104-11. [DOI: 10.1016/j.chroma.2013.10.008] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2013] [Revised: 09/30/2013] [Accepted: 10/01/2013] [Indexed: 11/19/2022]
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8
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Lei J, Zhang X. Open tubular columns with mixed-mode reversed-phase and weak anion-exchange stationary phase for capillary electrochromatography. J Sep Sci 2013; 36:1996-2002. [DOI: 10.1002/jssc.201201146] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2012] [Revised: 03/28/2013] [Accepted: 04/01/2013] [Indexed: 11/08/2022]
Affiliation(s)
- Jie Lei
- Department of Chemistry and Institute of Biomedical Science; Fudan University; Shanghai P. R. China
| | - Xiangmin Zhang
- Department of Chemistry and Institute of Biomedical Science; Fudan University; Shanghai P. R. China
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Mansour FR, Kirkpatrick CL, Danielson ND. Ion Exclusion Chromatography of Aromatic Acids. J Chromatogr Sci 2013; 51:655-65. [DOI: 10.1093/chromsci/bmt007] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
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10
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Lin X, Li Y, Xu D, Yang C, Xie Z. Rapid capillary electrochromatographic profiling of phytohormones on a hydrophilic interaction/strong anion-exchange mixed-mode monolith. Analyst 2013; 138:635-41. [DOI: 10.1039/c2an36354b] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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11
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Aydoğan C, Denizli A. Preparation and electrochromatographic characterization of methacrylate-based weak cation exchange columns for capillary electrochromatography. Analyst 2013; 138:2118-25. [DOI: 10.1039/c3an36377e] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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12
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Aydoğan C, Tuncel A, Denizli A. Polymethacrylate-based monolithic capillary column with weak cation exchange functionalities for capillary electrochromatography. J Sep Sci 2012; 35:1010-6. [DOI: 10.1002/jssc.201100927] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Affiliation(s)
- Cemil Aydoğan
- Department of Chemistry; Biochemistry division; Hacettepe University; Ankara Turkey
| | - Ali Tuncel
- Department of Chemical Engineering; Hacettepe University; Ankara Turkey
| | - Adil Denizli
- Department of Chemistry; Biochemistry division; Hacettepe University; Ankara Turkey
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13
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Wang X, Zheng Y, Zhang C, Yang Y, Lin X, Huang G, Xie Z. Preparation and characterization of hybrid-silica monolithic column with mixed-mode of hydrophilic and strong anion-exchange interactions for pressurized capillary electrochromatography. J Chromatogr A 2012; 1239:56-63. [PMID: 22503622 DOI: 10.1016/j.chroma.2012.03.071] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2011] [Revised: 03/19/2012] [Accepted: 03/22/2012] [Indexed: 11/27/2022]
Abstract
A novel organic-silica hybrid monolithic stationary phase with a mixed-mode of hydrophilic and strong anion-exchange interactions (HI-SAX) was prepared with a modified "one-pot" process of functional monomers and alkoxysilanes. Using a hydrosoluble initiator 2,2'-azobis(2-methylpropionamidine) dihydrochloride (AIBA), the homogeneous prepolymerization system of this hybrid monolith was successfully obtained by a simple operation. The polycondensation of alkoxysilanes (tetramethoxysilane (TMOS) and vinyl-trimethoxysilane (VTMS)) and the in situ copolymerization of a quaternary ammonium group-containing acrylic monomer ([2-(acryloyloxy)ethyl] trimethyl ammonium methyl sulfate (AETA)) on the precondensed siloxanes were achieved. The morphologies of the hybrid-silica monolithic matrixes were observed by SEM, and the performances of the organic-silica hybrid monolithic columns were investigated by pressurized capillary electrochromatography. The mechanical stability and reproducibility of the obtained hybrid monolithic column preformed acceptable. Both hydrophilic interaction chromatography mechanism and strong anion-exchanged interaction were investigated. A mixed mode of HI-SAX was obtained for the analysis of nucleotides with a good resolution, and the separation of polar and basic nucleic acid bases and nucleosides was also achieved without peak tailing.
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Affiliation(s)
- Xiao Wang
- Institute of Food Safety and Environmental Monitoring, Fuzhou University, Fuzhou, 350108, China
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14
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Wang Y, Deng QL, Fang GZ, Pan MF, Yu Y, Wang S. A novel ionic liquid monolithic column and its separation properties in capillary electrochromatography. Anal Chim Acta 2012; 712:1-8. [DOI: 10.1016/j.aca.2011.10.023] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2011] [Revised: 09/29/2011] [Accepted: 10/11/2011] [Indexed: 11/30/2022]
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15
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Zhu Y, Zhou C, Qin S, Ren Z, Zhang L, Fu H, Zhang W. A novel open‐tubular capillary electrochromatography with magnetic nanoparticle coating as stationary phase. Electrophoresis 2011; 33:340-7. [DOI: 10.1002/elps.201100337] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2011] [Revised: 09/03/2011] [Accepted: 09/05/2011] [Indexed: 01/02/2023]
Affiliation(s)
- Yaxian Zhu
- Shanghai Key Laboratory of Functional Materials Chemistry, East China University of Science and Technology, Shanghai, P. R. China
| | - Chaoran Zhou
- Key Laboratory of Functional Inorganic Material Chemistry, Ministry of Education of the People's Republic of China, Heilongjiang University, Harbin, P. R. China
| | - Sasa Qin
- Shanghai Key Laboratory of Functional Materials Chemistry, East China University of Science and Technology, Shanghai, P. R. China
| | - Zhiyu Ren
- Key Laboratory of Functional Inorganic Material Chemistry, Ministry of Education of the People's Republic of China, Heilongjiang University, Harbin, P. R. China
| | - Lingyi Zhang
- Shanghai Key Laboratory of Functional Materials Chemistry, East China University of Science and Technology, Shanghai, P. R. China
| | - Honggang Fu
- Key Laboratory of Functional Inorganic Material Chemistry, Ministry of Education of the People's Republic of China, Heilongjiang University, Harbin, P. R. China
| | - Weibing Zhang
- Shanghai Key Laboratory of Functional Materials Chemistry, East China University of Science and Technology, Shanghai, P. R. China
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16
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Preparation and Evaluation of Poly-l-Lysine Stationary Phase for Hydrophilic Interaction/Reversed-Phase Mixed-Mode Chromatography. Chromatographia 2011. [DOI: 10.1007/s10337-011-2120-5] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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17
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Ma TY, Li H, Tang AN, Yuan ZY. Ordered, mesoporous metal phosphonate materials with microporous crystalline walls for selective separation techniques. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2011; 7:1827-1837. [PMID: 21574251 DOI: 10.1002/smll.201100389] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/26/2011] [Indexed: 05/30/2023]
Abstract
Ordered, hexagonal, mesoporous metal (Ti, Zr, V, Al)-phosphonate materials with microporous crystalline walls are synthesized through a microwave-assisted procedure by using triblock copolymer F127 as the template. Corresponding metal chlorides and ethylene diamine tetra(methylene phosphonic acid) are chosen as the inorganic precursors and the coupling molecule, respectively. X-ray diffractometry, transmission electron microscopy, N(2) sorption, and thermogravimetry measurements confirm that the obtained metal phosphonates possess a hierarchically porous structure with pore sizes of 7.1-7.5 nm and 1.3-1.7 nm for mesopores and micropores, respectively, and the metal phosphonate materials are thermally stable up to around 450 °C with the pore structure and hybrid framework well preserved. Magic angle spinning NMR, Fourier-transform infrared spectroscopy, and X-ray photoelectron spectroscopy analyses indicate that the phosphonate groups are homogenously incorporated into the hybrid framework of the obtained materials. For the first time, the mesoporous hybrid materials are employed as the stationary phase in open tubular capillary electrochromatography technique for the separation of various substances including acidic, basic, and neutral compounds. These materials show good selectivity and reproducibility for this application.
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Affiliation(s)
- Tian-Yi Ma
- Institute of New Catalytic Materials Science, Key Laboratory of Advanced Energy Materials Chemistry (Ministry of Education), College of Chemistry, Nankai University, Tianjin, 300071, China
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18
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Wang X, Ding K, Yang C, Lin X, Lü H, Wu X, Xie Z. Sulfoalkylbetaine-based monolithic column with mixed-mode of hydrophilic interaction and strong anion-exchange stationary phase for capillary electrochromatography. Electrophoresis 2010; 31:2997-3005. [PMID: 20715128 DOI: 10.1002/elps.201000264] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
A novel monolithic stationary phase with mixed mode of hydrophilic and strong anion exchange (SAX) interactions based on in situ copolymerization of pentaerythritol triacrylate (PETA), N,N-dimethyl-N-methacryloxyethyl N-(3-sulfopropyl) ammonium betaine (DMMSA) and a selected quaternary amine acrylic monomer was designed as a multifunctional separation column for CEC. Although the zwitterionic functionalities of DMMSA and hydroxy groups of PETA on the surface of the monolithic stationary phase functioned as the hydrophilic interaction (HI) sites, the quaternary amine acrylic monomer was introduced to control the magnitude of the EOF and provide the SAX sites at the same time. Three different quaternary amine acrylic monomers were tested to achieve maximum EOF velocity and highest plate count. The fabrication of the zwitterionic monolith (designated as HI and SAX stationary phase) was carried out when [2-(acryloyloxy)ethyl]trimethylammonium methylsulfate was used as the quaternary amine acrylic monomer. The separation mechanism of the monolithic column was discussed in detail. For charged analytes, a mixed mode of HI and SAX was observed by studying the influence of mobile phase pH and salt concentration on their retentions on the poly(PETA-co-DMMSA-co-[2-(acryloyloxy)ethyl]trimethylammonium methylsulfate) monolithic column. The optimized monolith showed good separation performance for a range of polar analytes including nucleotides, nucleic acid bases and nucleosides, phenols, estrogens and small peptides. The column efficiencies greater than 192 000 theoretical plates/m for estriol and 135 000 theoretical plates/m for charged cytidine were obtained.
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Affiliation(s)
- Xiaochun Wang
- Institute of Food Safety and Environmental Monitoring, Fuzhou University, Fuzhou, P. R. China
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Li H, Ding GS, Chen J, Tang AN. Amphiphilic silica nanoparticles as pseudostationary phase for capillary electrophoresis separation. J Chromatogr A 2010; 1217:7448-54. [DOI: 10.1016/j.chroma.2010.09.050] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2010] [Revised: 09/14/2010] [Accepted: 09/15/2010] [Indexed: 11/25/2022]
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20
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Huang G, Zeng W, Lin X, Xie Z. Silica-based zwitterionic monolithic stationary phase for separation of neutral and ionized solutes using pressurized CEC. J Sep Sci 2010; 33:1625-32. [PMID: 20437413 DOI: 10.1002/jssc.200900764] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
A porous zwitterionic monolith was prepared by in situ covalent attachment of lysine to a gamma-glycidoxypropyltrimethosysilane-modified silica monolith. The prepared column was used to perform neutral and ionized solutes separations by pressurized (pCEC). Due to the zwitterionic nature of the resulting stationary phase, the monolithic column provided both electrostatic attraction and repulsion sites for electrochromatographic retention for ionized solutes. Separation of several nucleotides was investigated on the monolithic column. It was shown that the nucleotides could be separated based on hydrophilic and electrostatic interactions between the stationary phase and analyte. Besides, the separation property of the zwitterionic silica monolith was compared with the use of diamine-bonded silica monolith as stationary phase. As expected, the lysine monolith exhibited a lower retention for the five nucleotides, which was due to the dissociation of the external carboxylic acid groups, leading to electrostatic repulsion with negatively charged solutes. Under the same experimental conditions, separation of the five nucleotides on the zwitterionic column was in less than 8 min, while that on the diamine column was in approximately 60 min.
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Affiliation(s)
- Guihua Huang
- Department of Pharmaceutics, Fujian University of Traditional Chinese Medicine, Fuzhou, P. R. China
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Lin J, Lin J, Lin X, Wu X, Xie Z. Preparation of a neutral porous monolith and its evaluation in pressurized capillary electrochromatography with neutral and charged solutes. Electrophoresis 2010; 31:1674-80. [DOI: 10.1002/elps.200900669] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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22
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Preparation and Characterization of Butylaminopropyl Silica Monolithic Column for Capillary Electrochromatography. CHINESE JOURNAL OF ANALYTICAL CHEMISTRY 2010. [DOI: 10.3724/sp.j.1096.2010.00192] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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23
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Nischang I, Höltzel A, Tallarek U. Electrochromatographic retention of peptides on strong cation-exchange stationary phases. Electrophoresis 2010; 31:933-43. [DOI: 10.1002/elps.200900549] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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YE FG, HAN YY, WANG S, HUANG BJ, ZHAO SL. Preparation and Characterization of Butylaminopropyl Silica Monolithic Column for Capillary Electrochromatography. CHINESE JOURNAL OF ANALYTICAL CHEMISTRY 2010. [DOI: 10.1016/s1872-2040(09)60024-4] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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25
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Ye F, Wang S, Zhao S. Preparation and characterization of mixed-mode monolithic silica column for capillary electrochromatography. J Chromatogr A 2009; 1216:8845-50. [DOI: 10.1016/j.chroma.2009.10.071] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2009] [Revised: 10/16/2009] [Accepted: 10/23/2009] [Indexed: 11/27/2022]
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26
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Lin X, Zeng W, Wang X, Xie Z. Glycin-bonded silica monolithic column as zwitterionic stationary phase for hydrophilic interaction pressurized capillary electrochromatography. J Sep Sci 2009; 32:2767-75. [DOI: 10.1002/jssc.200900107] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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27
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Preparation of a mixed-mode hydrophilic interaction/anion-exchange polymeric monolithic stationary phase for capillary liquid chromatography of polar analytes. J Chromatogr A 2008; 1216:801-6. [PMID: 19108844 DOI: 10.1016/j.chroma.2008.11.099] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2008] [Revised: 11/23/2008] [Accepted: 11/26/2008] [Indexed: 11/23/2022]
Abstract
A novel cationic hydrophilic interaction monolithic stationary phase based on the copolymerization of 2-(methacryloyloxy)ethyltrimethylammonium methyl sulfate (META) and pentaerythritol triacrylate (PETA) in a binary porogenic solvent consisting of cyclohexanol/ethylene glycol was designed for performing capillary liquid chromatography. While META functioned as both the ion-exchange sites and polar ligand provider, the PETA, a trivinyl monomer, was introduced as cross-linker. The monolithic stationary phases with different properties were easily prepared by adjusting the amount of META in the polymerization solution as well as the composition of the porogenic solvent. The hydrophilicity of the monolith increased with increasing content of META in the polymerization mixture. A typical hydrophilic interaction chromatography mechanism was observed when the content of acetonitrile in the mobile phase was higher than 20%. The poly(META-co-PETA) monolith showed very good selectivity for neutral, basic and acidic polar analytes. For polar-charged analytes, both hydrophilic interaction and electrostatic interaction contributed to their retention. Peak tailing of basic compounds was avoided and the efficient separation of benzoic acid derivatives was obtained.
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Höltzel A, Tallarek U. Ionic conductance of nanopores in microscale analysis systems: where microfluidics meets nanofluidics. J Sep Sci 2007; 30:1398-419. [PMID: 17623420 DOI: 10.1002/jssc.200600427] [Citation(s) in RCA: 89] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
In this tutorial review we illustrate the origin and dependence on various system parameters of the ionic conductance that exists in discrete nanochannels as well as in nanoporous separation and preconcentration units contained as hybrid configurations, membranes, packed beds, or monoliths in microscale liquid phase analysis systems. A particular complexity arises as external electrical fields are superimposed on internal chemical and electrical potential gradients for tailoring molecular transport. It is demonstrated that the variety of geometries in which the microfluidic/nanofluidic interfaces are realized share common, fundamental features of coupled mass and charge transport, but that phenomena behind the key steps in a particular application can be significantly tuned, depending on the morphology of a material. Thus, the understanding of morphology-related transport in internal and external electrical potential gradients is critical to the performance of a device. This addresses a variety of geometries (slits, channels, filters, membranes, random or regular networks of pores, etc.) and applications, e. g., the gating, sensing, preconcentration, and separation in multifunctional miniaturized devices. Inherently coupled mass and charge transport through ion-permselective (charge-selective) microfluidic/nanofluidic interfaces is analyzed with a stepwise-added complexity and discussed with respect to the morphology of the charge-selective spatial domains. Within this scenario, the electrostatics and electrokinetics in microfluidic and nanofluidic channels, as well as the electrohydrodynamics evolving at microfluidic/nanofluidic interfaces, where microfluidics meets nanofluidics, define the platform of central phenomena.
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Affiliation(s)
- Alexandra Höltzel
- Institut für Verfahrenstechnik, Otto-von-Guericke-Universität, Magdeburg, Germany
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Lin J, Wu X, Lin X, Xie Z. Preparation of polymethacrylate monolithic stationary phases having bonded octadecyl ligands and sulfonate groups: electrochromatographic characterization and application to the separation of polar solutes for pressurized capillary electrochromatography. J Chromatogr A 2007; 1169:220-7. [PMID: 17875313 DOI: 10.1016/j.chroma.2007.08.061] [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: 06/26/2007] [Revised: 08/26/2007] [Accepted: 08/30/2007] [Indexed: 10/22/2022]
Abstract
In this report, the preparation of porous polymethacrylate-based monolithic columns by in situ copolymerization of octadecyl methacrylate (OMA), 3-sulfopropyl methacrylate (SPMA) and ethylene dimethacrylate (EDMA) in a binary porogenic solvent consisting of cyclohexanol/1,4-butanediol are proposed. These monoliths possess in their structures bonded octadecyl ligands and sulfonate groups and are evaluated in pressurized capillary electrochromatography (pCEC) system using small neutral and charged solutes. While the sulfonate groups are meant to generate the electroosmotic flow (EOF) necessary for transporting the mobile phase through the monolithic capillary; the octadecyl ligands are introduced to provide the nonpolar sites for chromatographic retention for neutral solutes. However, incorporating the sulfonate groups in the monoliths does not only support the EOF but also exhibit hydrophilic interaction as well as electrostatic interaction/repulsion with the monoliths in addition to electrophoretic migration with polar charged solutes (e.g., nucleotides). The monolithic stationary phases at different EOF velocities are easily prepared by altering the amount of SPMA in the polymerization solution as well as the composition of the porogenic solvent. Optimum EOF velocity, the highest efficiency and adequate chromatographic retention are obtained when 0.6% SPMA is added to the reaction mixture. Under these conditions, rapid separation and high plate counts reaching greater than 170,000 plates/m are readily obtained.
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Affiliation(s)
- Jian Lin
- Department of Chemistry, Fuzhou University, Fuzhou 350002, China
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30
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Freitag R, Hilbrig F. Theory and practical understanding of the migration behavior of proteins and peptides in CE and related techniques. Electrophoresis 2007; 28:2125-44. [PMID: 17557365 DOI: 10.1002/elps.200600792] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
CEC is defined as an analytical method, where the analytes are separated on a chromatographic column in the presence of an applied voltage. The separation of charged analytes in CEC is complex, since chromatographic interaction, electroosmosis and electrophoresis contribute to the experimentally observed behavior. The putative contribution of effects such as surface electrodiffusion has been suggested. A sound theoretical treatment incorporating all effects is currently not available. The question of whether the different effects contribute in an independent or an interdependent manner is still under discussion. In this contribution, the state-of-the-art in the theoretical description of the individual contributions as well as models for the retention behavior and in particular possible dimensionless 'retention factors' is discussed, together with the experimental database for the separation of charged analytes, in particular proteins and peptides, by CEC and related techniques.
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Affiliation(s)
- Ruth Freitag
- Process Biotechnology, University of Bayreuth, Bayreuth, Germany.
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31
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Hu J, Xie C, Tian R, He Z, Zou H. Separation of basic and acidic compounds by capillary electrochromatography using monolithic silica capillary columns with zwitterionic stationary phase. J Sep Sci 2007; 30:891-9. [PMID: 17536734 DOI: 10.1002/jssc.200600173] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
A novel monolithic silica column with zwitterionic stationary phase was prepared by in-situ covalent attachment of phenylalanine to a 3-glycidoxypropyltriethoxysilane-modified silica monolith. Due to the zwitterionic nature of the resulting stationary phase, the density and sign of the net surface charge, and accordingly the direction and magnitude of electroosmotic flow in this column during capillary electrochromatography could be manipulated by adjusting the pH values of the mobile phase. CEC separations of various acidic and basic compounds were performed on the prepared column in anodic and weakly cathodic EOF modes, respectively. The peak tailing of basic compounds in CEC on a silica column could be alleviated at optimized buffer compositions. Besides the electrophoretic mechanism and weak hydrophobic interaction, weak cation- and anion-exchange interactions are also involved in the separations of acids and bases, respectively, on the zwitterionic column.
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Affiliation(s)
- Jiwei Hu
- College of Chemistry and Molecular Sciences, Wuhan University, Wuhan, China
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32
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Ye F, Xie Z, Wong KY. Monolithic silica columns with mixed mode of hydrophilic interaction and weak anion-exchange stationary phase for pressurized capillary electrochromatography. Electrophoresis 2006; 27:3373-80. [PMID: 16865668 DOI: 10.1002/elps.200500869] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
A silica-based monolithic column as polar stationary phase is proposed for pressurized CEC (pCEC). The monolithic silica matrix from a sol-gel process was chemically modified by 3-aminopropyltrimethoxysilane to produce a column for hydrophilic interaction applications. The amino groups on the surface of the polar stationary phase generated anodic EOF under acidic conditions and served at the same time as a weak anion-exchanger. The anion solutes such as nucleotides were separated by the mixed mode mechanism, which comprised hydrophilic interaction, weak anion-exchange, and electrophoresis. The influences of buffer concentration and organic modifier content on the separation of nucleotides by pCEC have been investigated. In addition, the monolithic silica columns were also able to separate various polar compounds such as phenols, nucleic acid bases, and nucleosides in the hydrophilic interaction CEC mode.
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Affiliation(s)
- Fanggui Ye
- The MOE Key Laboratory of Analysis and Detection Technology for Food Safety, Department of Chemistry, Fuzhou University, Fuzhou, Fujian, China
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33
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Hu J, Xie C, Tian R, He Z, Zou H. Hybrid silica monolithic column for capillary electrochromatography with enhanced cathodic electroosmotic flow. Electrophoresis 2006; 27:4266-72. [PMID: 17006882 DOI: 10.1002/elps.200600171] [Citation(s) in RCA: 28] [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
A hybrid silica monolithic stationary phase for RP CEC was prepared by in situ co-condensation of (3-mercaptopropyl)-trimethoxysilane (MPTMS), phenyltriethoxysilane (PTES), and tetraethoxysilane (TEOS) via a sol-gel process. The thiol groups on the surface of the stationary phase were oxidized to sulfonic acids by peroxytrifluoroacetic acid. The introduced sulfonic acid moieties on the monoliths were characterized by a strong and relatively stable EOF in a broad pH range from 2.35 to 7.0 in CEC. Aromatic acids and neutral compounds can be simultaneously separated in this column under cathodic EOF. The CEC column exhibited a typical RP chromatographic mechanism for neutral compounds due to the introduced phenyl groups.
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Affiliation(s)
- Jiwei Hu
- College of Chemistry and Molecular Sciences, Wuhan University, Wuhan, P R China
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34
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Ding G, Da Z, Yuan R, Bao JJ. Reversed-phase and weak anion-exchange mixed-mode silica-based monolithic column for capillary electrochromatography. Electrophoresis 2006; 27:3363-72. [PMID: 16944466 DOI: 10.1002/elps.200500931] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
A silica-based CEC monolithic column with mixed modes of RP and weak anion-exchange (WAX) was successfully prepared by using the sol-gel technique at mild temperature. The synthesizing procedure was optimized by changing the ratios of tetraethoxysilane (TEOS), aminopropyltriethoxysilane (APTES), and octyltriethoxysilane (C(8)-TEOS) in the mixture. While serving as WAX group, the amino group dominated the charge on the surface of the capillary column and generated an EOF from cathode to anode at low pH. At pH above 7.5, a cathodic EOF was observed due to the full ionization of silanol group and the suppression in the ionization of amino group. The morphology of monolithic columns was examined by SEM, and the performance of column was evaluated in detail by separating different kinds of compounds. As expected, the monolithic column exhibited RP chromatographic behavior for neutral solutes. Fast and efficient separation of six aromatic acids was obtained using acidic mobile phase with column efficiency up to 160,000 plates/m. Symmetrical peaks can be obtained for aromatic amines because positively charged amino groups on the surface can effectively minimize the adsorption of positively charged analytes to the stationary phase.
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Affiliation(s)
- Guosheng Ding
- School of Pharmaceutical Sciences and Technologies, Tianjin University, Tianjin, China
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35
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Zhang K, Yan C, Zhang Z, Wang Q, Gao R. Mixed Mode of Hydrophilic and Ionic Interaction Pressurized Capillary Electrochromatography for Separation of Basic Compounds. J LIQ CHROMATOGR R T 2006. [DOI: 10.1081/jlc-120022397] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Affiliation(s)
- Kai Zhang
- a State Key Laboratory of Elemento‐Organic Chemistry , Nankai University , Tianjin , 300071 , P.R. China
| | - Chao Yan
- b Unimicro Technologies, Inc. , Pleasanton , California , USA
| | - Zhichao Zhang
- a State Key Laboratory of Elemento‐Organic Chemistry , Nankai University , Tianjin , 300071 , P.R. China
| | - Qinsun Wang
- a State Key Laboratory of Elemento‐Organic Chemistry , Nankai University , Tianjin , 300071 , P.R. China
| | - Ruyu Gao
- a State Key Laboratory of Elemento‐Organic Chemistry , Nankai University , Tianjin , 300071 , P.R. China
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36
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Steiner F, Scherer B. Separation of small peptides by electrochromatography on silica-based reversed phases and hydrophobic anion exchange phases. Electrophoresis 2005; 26:1996-2004. [PMID: 15852351 DOI: 10.1002/elps.200410325] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
Peptide separations are regarded as a promising application of capillary electrochromatography (CEC) and, at the same time, a suitable model to elucidate its mixed separation mechanism when charged analytes are involved. In this paper, studies on the separation of small peptides (2-4 amino acids) on a Spherisorb octadecyl silane (ODS) phase at acidic pH and on a strong anion exchange (SAX)/C18 mixed mode phase at weakly basic pH are reported. For the ODS phase a comparison of CEC, capillary zone electrophoresis (CZE) and high-performance liquid chromatography (HPLC) under identical buffer/eluent conditions is presented. The predicted retention factors for CEC under the assumption of simple superposition of HPLC retention and CZE migration matched the measured results for the peptides that had small retention factors in HPLC. For both types of stationary phases, a variation of the acetonitrile content in the mobile phase led to a wide range of retention factors, including negative values when co-electroosmotic migration was dominant. Though both the ODS and the SAX/C18 phase offer unique advantages, the SCX/C18 phase at pH 9 provides more flexibility to alter separation selectivity for the selected peptides.
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Affiliation(s)
- Frank Steiner
- Instrumental Analysis and Bioanalysis, Saarland University, D-66041 Saarbrücken, Germany.
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37
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Progent F, Taverna M. Retention behaviour of peptides in capillary electrochromatography using an embedded ammonium in dodecacyl stationary phase. J Chromatogr A 2004; 1052:181-9. [PMID: 15527136 DOI: 10.1016/j.chroma.2004.08.107] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The potential of a silica stationary phase bearing an embedded cationic quaternary amine in dodecacyl chain, to separate peptides by capillary electrochromatography (CEC) has been evaluated. The ability of this stationary phase, to generate a consistent anodic electroosmotic flow was first evaluated. This flow was found to be independent of pH over a wide range (2-12), of the acetonitrile percentage in the electrolyte. The stability of the stationary phase evaluated through the electroosmotic flow variations was demonstrated at extreme pH values (2.5 and 9.1). A careful examination of the influence of mobile phase conditions (acetonitrile percentage, salt concentration and nature of buffer) on the electrochromatographic retention and electrophoretic migration behaviour of different standard peptides was carried out. In acidic conditions, the electrokinetic contribution appears to be predominant compared to the chromatographic one. Several types of chromatographic interactions, reversed-phase partitioning and anion exchange, were involved in the CEC of peptides, whereas repulsive electrostatic interaction could be considered as negligible. This stationary phase affords different selectivity compared to that observed on a C18 stationary phase. Finally, the method was applied to the peptide mapping of beta-lactoglobulin and human growth hormone under unpressurized and isocratic elution.
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Affiliation(s)
- Frédéric Progent
- Groupe de Chimie Analytique de Paris-Sud, Faculté de Pharmacie, Châtenay-Malabry, France
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38
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Yan L, Zhang Q, Zhang J, Zhang L, Li T, Feng Y, Zhang L, Zhang W, Zhang Y. Hybrid organic–inorganic monolithic stationary phase for acidic compounds separation by capillary electrochromatography. J Chromatogr A 2004; 1046:255-61. [PMID: 15387196 DOI: 10.1016/j.chroma.2004.06.024] [Citation(s) in RCA: 101] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
A novel type of organic-inorganic hybrid porous silica-based monolithic stationary phase for capillary electrochromatography (CEC) has been developed by sol-gel chemistry combined with supramolecular template-based approach in a simple and rapid manner. Both chromatographic interaction and electrophoretic migration contribute to the separation of acidic compounds by the monolithic column. Eight organic acids were separated rapidly with column efficiency up to 267,000 theoretical plates/m. The influences of buffer concentration and organic modifier content on the separation have been investigated. In addition, the hybrid monolithic column was used to separate triterpenoids from Ganoderma lucidum.
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Affiliation(s)
- Lijuan Yan
- Department of Chemistry, Wuhan University, Wuhan 430072, China
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39
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Fu H, Xie C, Xiao H, Dong J, Hu J, Zou H. Monolithic columns with mixed modes of reversed-phase and anion-exchange stationary phase for capillary electrochromatography. J Chromatogr A 2004; 1044:237-44. [PMID: 15354443 DOI: 10.1016/j.chroma.2004.04.076] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
A capillary electrochromatography (CEC) monolithic column with mixed modes of reversed-phase and anion-exchange stationary phases was prepared by in situ polymerization of 2-(methacryloxy)ethyltrimethylammonium methyl sulfate (MEAMS) and ethylene dimethacrylate (EDMA) in a binary porogenic solvent consisting 1-propanol and 1,4-butanediol. The ammonium groups on the surface of the stationary phase generate an electroosmotic flow (EOF) from cathode to anode, and serve as a strong anion-exchange stationary phase at the same time. The EOF of the stationary phase can be determined by the amount of MEAMS monomer in reaction mixtures during the polymerization. The monolithic stationary phases exhibited reversed-phase chromatographic behavior toward neutral solutes. For charged solutes, hydrophobic as well as electrostatic interaction/repulsion with the monoliths was observed. Separations of aromatic compounds and basic compounds on the prepared column were performed under the mode of CEC. Peak tailing of basic compounds was avoided and the efficient separation of aromatic acids was achieved using neutral mobile phase due to the same direction of EOF and electrophorestic mobility of negatively charged solutes.
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Affiliation(s)
- Hongjing Fu
- National Chromatographic R&A Center, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116011, China
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40
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Jiskra J, Claessens HA, Cramers CA. Stationary and mobile phases in capillary electrochromatography (CEC). J Sep Sci 2003. [DOI: 10.1002/jssc.200301305] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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41
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Zhang K, Gao R, Jiang Z, Yao C, Zhang Z, Wang Q, Yan C. Pressurized capillary electrochromatography separation of peptides with strong cation exchange and hydrophilic interaction. J Sep Sci 2003. [DOI: 10.1002/jssc.200301590] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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42
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Fu H, Jin W, Xiao H, Huang H, Zou H. Peptide separation in hydrophilic interaction capillary electrochromatography. Electrophoresis 2003; 24:2084-2091. [PMID: 12858379 DOI: 10.1002/elps.200305462] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
Separation of small peptides by hydrophilic interaction capillary electrochromatography (HI-CEC) has been investigated. The negative surface charge of a hydrophilic, strong-cation-exchange stationary phase (PolySULFOETHYL A) provided a substantial cathodic electroosmotic flow (EOF). The influence of acetonitrile content, ionic strength, mobile phase pH as well as applied voltage on the migration of the peptides was studied. Possible retention mechanisms of the peptides in HI-CEC were discussed. It was found that hydrophilic interaction between the solutes and the stationary phase played a major role in this system, especially when mobile phases with high acetonitrile content were used. However, an ion-exchange mechanism and electrophoretic mobility also affect the migration of the peptides in HI-CEC. Elution order and selectivity was proved to be different in HI-CEC and capillary zone electrophoresis (CZE), thus revealing the potential of HI-CEC as a complementary technique to CZE for the separation of peptides. Efficiency and selectivity of HI-CEC for the separation of peptides were demonstrated by baseline separating nine peptides in 6 min.
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Affiliation(s)
- Hongjing Fu
- National Chromatographic R&A Center, Dalian Institute of Chemical Physics, The Chinese Academy of Sciences, Dalian, China
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43
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Charvátová J, Kasicka V, Deyl Z, Král V. Influencing electroosmotic flow and selectivity in open tubular electrochromatography by tetrakis(pentafluorophenyl)porphyrin as capillary wall modifier. J Chromatogr A 2003; 990:111-9. [PMID: 12685589 DOI: 10.1016/s0021-9673(02)02004-6] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
A physically adsorbed and covalently bonded porphyrin derivative, 5,10,15,20-tetrakis(pentafluorophenyl)porphyrin, H2TPFPP, has been used as a fused-silica capillary wall modifier in open tubular capillary electrochromatography (OT-CEC), and its influence on the electroosmotic flow (EOF) velocity and on the selectivity of OT-CEC separations of a set of model aromatic carboxylic acids has been tested. Whereas most of the coatings of this category bring about an increase in selectivity with a concomitant slow down of the EOF, H2TPFPP coating, depending on pH of the background electrolyte used, resulted both in decreasing of EOF at pH 8.5 by 5% and in increasing of EOF by 10-43% at pH 6 and 5, respectively. The separation efficiency and the resolution of aromatic carboxylic acids separation in coated capillaries, namely in that one with covalent coating, were better than in the bare fused-silica capillary. The perspectives of H2TPFPP as capillary wall modifier are visualized in introducing well defined electroosmotic properties of materials used for miniaturized separation channels preparation in chip-based electromigration devices.
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Affiliation(s)
- Jana Charvátová
- Institute of Chemical Technology, Technická 5, 166 28 Prague 6, Czech Republic
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44
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Zhang L, Ping G, Zhang L, Zhang W, Zhang Y. Preparation and characterization of monolithic columns for capillary electrochromatography with weak electroosmotic flow. J Sep Sci 2003. [DOI: 10.1002/jssc.200390039] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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45
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De Rossi A, Desiderio C. Separation of negatively charged nonsteroidal anti-inflammatory drugs by reversed-phase capillary electrochromatography. J Chromatogr A 2003; 984:283-90. [PMID: 12564700 DOI: 10.1016/s0021-9673(02)01850-2] [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] [Indexed: 10/27/2022]
Abstract
Reversed-phase capillary electrochromatography in a 5-microm C18 fully packed capillary was employed to optimize the separation of negatively charged nonsteroidal anti-inflammatory drugs. The effect of the physico-chemical parameters and different analysis modes on the separation of 2-arylpropionic acids was studied and evaluated. The mobile phase composition, buffer type, concentration and pH differently influenced the peak efficiency and resolution, selectively modulating the analytes interaction with the stationary phase. The use of zwitterionic MES or acetate mobile phases strongly modulated the analytes migration order and peak efficiency. The optimum experimental conditions were found in MES buffer, pH 5.0, containing the 75% acetonitrile-methanol (1:1). All the analytes were baseline separated in a mixture in less than 13 min with peak efficiencies in the range of 78,500-84,200 N/m. Under these conditions the analytes were negatively charged and their effective electrophoretic mobilities played a role in the separation. The analysis of different pharmaceutical preparations containing anti-inflammatory drugs, e.g. drops and tablets, is also presented after a very simple sample pretreatment.
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Affiliation(s)
- Antonella De Rossi
- Institute of Chemical Methodologies, National Council of Research, Rome Research Area, P.O. Box 10, 00016 Monterotondo Scalo, Rome, Italy
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46
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Svec F. Capillary electrochromatography: a rapidly emerging separation method. ADVANCES IN BIOCHEMICAL ENGINEERING/BIOTECHNOLOGY 2002; 76:1-47. [PMID: 12126266 DOI: 10.1007/3-540-45345-8_1] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/25/2023]
Abstract
This overview concerns the new chromatographic method--capillary electrochromatography (CEC)--that is recently receiving remarkable attention. The principles of this method based on a combination of electroosmotic flow and analyte-stationary phase interactions, CEC instrumentation, capillary column technology, separation conditions, and examples of a variety of applications are discussed in detail.
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Affiliation(s)
- Frantisek Svec
- Department of Chemistry, University of California, Berkeley 94720-1460, USA.
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47
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An original way to use a β-cyclodextrin-bonded silica stationary phase in electrochromatography. Application to the achiral separation of nucleobases and nucleosides. Chromatographia 2002. [DOI: 10.1007/bf02490246] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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48
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Ye M, Zou H, Wu R, Fu H, Lei Z. Modeling and optimization for separation of ionic solutes in pressurized flow capillary electrochromatography. J Sep Sci 2002. [DOI: 10.1002/1615-9314(20020501)25:7<416::aid-jssc416>3.0.co;2-7] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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49
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Abstract
A review is presented of the most important recent applications of capillary electrochromatography (CEC) for the analysis of acidic, basic, and neutral compounds, of biomolecules, environmental substances, natural products, pharmaceuticals, and chiral compounds. Packed-column CEC (packed-CEC), open-tubular (OT-CEC), as well as pressure-assisted CEC (pseudo-CEC) are hereby considered. Papers published between July 1999 and April 2001 were taken into account. Applications before July 1999 have been reviewed in Electrophoresis 1999, 20, 3027-3065.
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Affiliation(s)
- G Vanhoenacker
- Ghent University, Department of Organic Chemistry, Belgium
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50
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Wu R, Zou H, Ye M, Lei Z, Ni J. Capillary electrochromatography for separation of peptides driven with electrophoretic mobility on monolithic column. Anal Chem 2001; 73:4918-23. [PMID: 11681467 DOI: 10.1021/ac010413y] [Citation(s) in RCA: 84] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
A mode of capillary electrochromatography for separation of ionic compounds driven by electrophoretic mobility on a neutrally hydrophobic monolithic column was developed. The monolithic column was prepared from the in situ copolymerization of lauryl methacrylate and ethylene dimethacrylate to form a C12 hydrophobic stationary phase. It was found that EOF in this hydrophobic monolithic column was very poor, even the pH value of mobile phase at 8.0. The peptides at acidic buffer were separated on the basis of their differences in electrophoretic mobility and hydrophobic interaction with the stationary phase; therefore, different separation selectivity can be obtained in CEC from that in capillary zone electrophoresis (CZE). Separation of peptides has been realized with high column efficiency (up to 150,000 plates/meter) and good reproducibility (migration time with RSD <0.5%), and all of the peptides, including some basic peptides, showed good peak symmetry. Effects of the mobile phase compositions on the retention of peptides at low pH have been investigated in a hydrophobic capillary monolithic column. The significant difference in selectivity of peptides in CZE and CEC has been observed. Some peptide isomers that cannot be separated by CZE have been successfully separated on the capillary monolithic column in this mode with the same buffer used.
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Affiliation(s)
- R Wu
- National Chromatographic R&A Center, Dalian Institute of Chemical Physics, The Chinese Academy of Sciences.
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