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Neequaye T, El Rassi Z. Poly(carboxyethyl acrylate-co-ethylene glycol dimethacrylate) precursor monolith with bonded Tris ligands for use in hydrophilic interaction capillary electrochromatography. J Chromatogr A 2023; 1695:463933. [PMID: 36966604 DOI: 10.1016/j.chroma.2023.463933] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2023] [Revised: 03/13/2023] [Accepted: 03/15/2023] [Indexed: 03/19/2023]
Abstract
The facile preparation of a monolithic capillary column with surface bound polar ligands for use in hydrophilic interaction capillary electrochromatography is described. It involved the conversion of poly(carboxyethyl acrylate[CEA]-co-ethylene glycol dimethacrylate[EDMA]) precursor monolith (the so-called carboxy monolith) into a Tris bonded monolith by a post-polymerization functionalization process in the presence of a water soluble carbodiimide, namely N-(3-dimethylaminopropyl)-N´-ethylcarbodiimidehydrochloride. The carbodiimide assisted conversion, allowed the covalent attachment of the carboxyl group of the precursor monolith to the amino group of the Tris ligand via a stable amide linkage. This resulted in the formation of Tris poly(CEA-co-EDMA) monolith, which exhibited the typical retention behavior of hydrophilic interaction stationary phase when analyzing polar and slightly polar neutral or charged compounds. In fact, neutral polar species such as dimethylformamide, formamide and thiourea were retained in the order of increased polarity with acetonitrile rich mobile phase. Also, neutral p-nitrophenyl maltooligosaccharides (PNP-maltooligosaccharides) served as a polar homologous series for gauging the hydrophilicity of the Tris poly(CEA-co-EDMA) monolith, thus forming a versatile testing homologous series for other hydrophilic columns. Other polar anionic species (e.g., hydroxy benzoic acids and nucleotides) and weakly polar anionic compounds (e.g., dansyl amino acids and phenoxy acid herbicides) as well as polar weak bases namely nucleobases and nucleosides were used to probe the hydrophilic characters of the Tris poly(CEA-co-EDMA) monolith. The various polar and weakly polar compounds just mentioned revealed the wide potentiality of the hydrophilic interaction column under investigation.
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2
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Neequaye T, El Rassi Z. Poly(carboxyethyl acrylate-co-ethylene glycol dimethacrylate) precursor monolith with bonded octadecyl ligands for use in reversed-phase capillary electrochromatography. Electrophoresis 2021; 42:2656-2663. [PMID: 34324209 DOI: 10.1002/elps.202100117] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2021] [Revised: 07/05/2021] [Accepted: 07/24/2021] [Indexed: 11/06/2022]
Abstract
A carboxy precursor monolithic column, namely poly(carboxy ethyl acrylate-co-ethylene glycol dimethacrylate) was first produced in a 100 μm i.d. fused-silica capillary and subsequently surface bonded with n-octadecyl (C18 ) ligands by a post-polymerization functionalization process with octadecylamine in the presence of N,N´-dicyclohexylcarbodiimide. The bonding of octadecyl ligands was achieved via an amide linkage between the carboxy functions of the precursor monolith and the amino group of the octadecylamine compound. The resulting C18 monolith exhibited a very low electroosmotic flow (EOF), a fact that required the incorporation of small amounts of 2-acrylamido-2-methylpropane sulfonic acid (AMPS) in the polymerization solution to produce a precursor monolith with fixed negative charges of sulfonate groups. This may indicate that the conjugation of the carboxy functions with octadecylamine occurred to a large extent so that the amount of residual carboxy functions was sparsely dispersed and not enough to produce a desirable EOF. The EOF velocity of the C18 column having fixed negative charges provided by the incorporated AMPS increased with increasing ACN content of the mobile phase signaling an increased binding of mobile phase ions to the polar amide linkages near the monolithic surface, and a decreased viscosity of the mobile phase, both of which would result in increased EOF velocity. The C18 monolithic column constituted a novel nonpolar sorbent for reversed-phase capillary electrochromatography for nonpolar solutes, e.g., alkylbenzenes, alkylphenyl ketones, and polyaromatic hydrocarbons, and slightly polar compounds including phenol and chlorophenols. The C18 monolithic column exhibited relatively high selectivity toward chlorophenols differing by one chloro substituent.
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Affiliation(s)
- Theophilus Neequaye
- Department of Chemistry, Oklahoma State University, Stillwater, Oklahoma, USA
| | - Ziad El Rassi
- Department of Chemistry, Oklahoma State University, Stillwater, Oklahoma, USA
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3
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Gökaltun A, Tuncel A. Post-polymerization modification of a new reactive monolith for reversed phase and hydrophilic interaction capillary electrochromatography of neutral, polar, and biologically active compounds. POLYM ADVAN TECHNOL 2018. [DOI: 10.1002/pat.4320] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Affiliation(s)
- Aslıhan Gökaltun
- Hacettepe University; Chemical Engineering Department; Ankara 06532 Turkey
| | - Ali Tuncel
- Hacettepe University; Chemical Engineering Department; Ankara 06532 Turkey
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4
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Wang J, Ding C, Xiao J, Jia W, Chen Y, Lin X, Xie Z. Quinine-modified polymer monolithic column with reversed-phase /strong anion-exchange mixed-mode for pressurized capillary electrochromatography. Electrophoresis 2018; 39:1504-1511. [DOI: 10.1002/elps.201800003] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/01/2018] [Revised: 02/28/2018] [Accepted: 03/13/2018] [Indexed: 11/05/2022]
Affiliation(s)
- Jiabin Wang
- Institute of Food Safety and Environment Monitoring; Fuzhou University; Fuzhou P. R. China
- Institute of Biomedical and Pharmaceutical Technology; Fuzhou University; Fuzhou P. R. China
| | - Changying Ding
- Institute of Food Safety and Environment Monitoring; Fuzhou University; Fuzhou P. R. China
| | - Jianhua Xiao
- Institute of Biomedical and Pharmaceutical Technology; Fuzhou University; Fuzhou P. R. China
| | - Wenchao Jia
- Institute of Food Safety and Environment Monitoring; Fuzhou University; Fuzhou P. R. China
| | - Yongxuan Chen
- Fujian Inspection and Research Institute for product quality; National Center of Processed Foods Quality Supervision and Inspection; Fuzhou P. R. China
| | - Xucong Lin
- Institute of Food Safety and Environment Monitoring; Fuzhou University; Fuzhou P. R. China
| | - Zenghong Xie
- Institute of Food Safety and Environment Monitoring; Fuzhou University; Fuzhou P. R. China
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Al-Massaedh “AA, Pyell U. Mixed-Mode Acrylamide-Based Continuous Beds Bearing tert-Butyl Groups for Capillary Electrochromatography Synthesized Via Complexation of N-tert-Butylacrylamide with a Water-Soluble Cyclodextrin. Part II: Effect of Capillary Size and Polymerization Conditions on Morphology and Chromatographic Efficiency. Chromatographia 2017. [DOI: 10.1007/s10337-017-3408-x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
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6
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Rathnasekara R, El Rassi Z. Polar silica-based stationary phases. Part I - Singly and doubly layered sorbents consisting of TRIS-silica and chondroitin sulfate A-TRIS-silica for hydrophilic interaction liquid chromatography. Electrophoresis 2017; 38:1582-1591. [DOI: 10.1002/elps.201600562] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2016] [Revised: 02/11/2017] [Accepted: 02/16/2017] [Indexed: 11/10/2022]
Affiliation(s)
| | - Ziad El Rassi
- Department of Chemistry; Oklahoma State University; Stillwater OK USA
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7
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Khadka S, El Rassi Z. Postpolymerization modification of a hydroxy monolith precursor. Part I. Epoxy alkane and octadecyl isocyanate modified poly (hydroxyethyl methacrylate-co-pentaerythritol triacrylate) monolithic capillary columns for reversed-phase capillary electrochroma. Electrophoresis 2016; 37:3160-3171. [DOI: 10.1002/elps.201600321] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2016] [Revised: 08/31/2016] [Accepted: 09/02/2016] [Indexed: 11/11/2022]
Affiliation(s)
| | - Ziad El Rassi
- Department of Chemistry; Oklahoma State University; Stillwater OK USA
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8
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Aydoğan C, El Rassi Z. Monolithic stationary phases with incorporated fumed silica nanoparticles. Part II. Polymethacrylate-based monolithic column with “covalently” incorporated modified octadecyl fumed silica nanoparticles for reversed-phase chromatography. J Chromatogr A 2016; 1445:62-7. [DOI: 10.1016/j.chroma.2016.03.083] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2015] [Revised: 03/12/2016] [Accepted: 03/28/2016] [Indexed: 01/25/2023]
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9
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Wang H, Ou J, Bai J, Liu Z, Yao Y, Chen L, Peng X, Zou H. Improving permeability and chromatographic performance of poly(pentaerythritol diacrylate monostearate) monolithic column via photo-induced thiol-acrylate polymerization. J Chromatogr A 2016; 1436:100-8. [DOI: 10.1016/j.chroma.2016.01.063] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2015] [Revised: 01/18/2016] [Accepted: 01/23/2016] [Indexed: 10/22/2022]
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10
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Jonnada M, Rathnasekara R, El Rassi Z. Recent advances in nonpolar and polar organic monoliths for HPLC and CEC. Electrophoresis 2014; 36:76-100. [PMID: 25266173 DOI: 10.1002/elps.201400426] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2014] [Revised: 09/20/2014] [Accepted: 09/22/2014] [Indexed: 01/17/2023]
Abstract
This article is aimed at providing a review of the progress made in the field over the period 2011 to present in order to expand in parts on two previous reviews (S. Karenga and Z. El Rassi, Electrophoresis, 2011, 32, 90-104; D. Gunasena and Z. El Rassi, Electrophoresis, 2012, 33, 251-261). In brief, this review article describes progress made in nonpolar and polar monoliths used in RP HPLC and CEC and in hydrophilic interaction LC/CEC, respectively. This article is by no means an exhaustive review of the literature; it is rather a survey of the recent progress made in the field with 69 references published on nonpolar and polar polymeric monoliths.
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Affiliation(s)
- Murthy Jonnada
- Department of Chemistry, Oklahoma State University, Stillwater, OK, USA
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Preparation and evaluation of a novel monolithic column containing double octadecyl chains for reverse-phase micro high performance liquid chromatography. J Chromatogr A 2014; 1345:174-81. [DOI: 10.1016/j.chroma.2014.04.036] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2014] [Revised: 04/09/2014] [Accepted: 04/10/2014] [Indexed: 12/28/2022]
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12
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Al-Massaedh “AA, Pyell U. Adamantyl-group containing mixed-mode acrylamide-based continuous beds for capillary electrochromatography. Part III. Optimization of the chromatographic efficiency. J Chromatogr A 2014; 1325:186-94. [DOI: 10.1016/j.chroma.2013.11.003] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2013] [Revised: 10/29/2013] [Accepted: 11/01/2013] [Indexed: 02/01/2023]
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13
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Cheng J, Chen X, Cai Y, He Y, Chen Z, Lin Z, Zhang L. Preparation and evaluation of a hydrophilic poly(2-hydroxyethyl methacrylate-co-N,N'-methylene bisacrylamide) monolithic column for pressurized capillary electrochromatography. Electrophoresis 2013; 34:1189-96. [PMID: 23404784 DOI: 10.1002/elps.201200523] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2012] [Revised: 12/25/2012] [Accepted: 12/26/2012] [Indexed: 11/05/2022]
Abstract
A polar polymethacrylate-based monolithic column was introduced and evaluated as a hydrophilic interaction CEC stationary phase. The monolithic stationary phase was prepared by in situ copolymerization of a neutral monomer 2-hydroxyethyl methacrylate and a polar cross-linker N,N'-methylene bisacrylamide in a binary porogenic solvent consisting of dodecyl alcohol and toluene. The hydroxyl and amino groups at the surface of the monolithic stationary phase provided polar sites which were responsible for hydrophilic interactions. The composition and proportion of the polymerization mixture was investigated in detail. The mechanical stability and reproducibility of the obtained monolithic column preformed was satisfied. The effects of pH and organic solvent content on the EOF and the separation of amines, nucleosides, and narcotics on the optimized monolithic column were investigated. A typical hydrophilic interaction CEC was observed on the neutral polar stationary phase. The optimized monolithic column can obtain high-column efficiencies with 62,000-126,000 theoretical plates/m and the RSDs of column-to-column (n = 9), run-to-run (n = 5), and day-to-day (n = 3) reproducibility were less than 6.3%. The calibration curves of these five narcotics exhibited good linearity with R in the range of 0.9959-0.9970 and linear ranges of 1.0-200.0 μg/mL. The detection limits at S/N = 3 were between 0.2 and 1.2 μg/mL. The recoveries of the separation of narcotics on the column were in the range of 84.0-108.6%. The good mechanical stability, reproducibility, and quantitation capacity was suitable for pressure-assisted CEC applications.
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Affiliation(s)
- Jintian Cheng
- Ministry of Education Key Laboratory of Analysis and Detection for Food Safety, Fujian Provincial Key Laboratory of Analysis and Detection for Food Safety, College of Chemistry and Chemical Engineering, Fuzhou University, Fuzhou, Fujian, PR China
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14
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Capillary Electrophoresis and Capillary Electrochromatography. CHROMATOGRAPHY 2013. [DOI: 10.1002/9780471980582.ch13] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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15
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Gunasena DN, El Rassi Z. Neutral, charged and stratified polar monoliths for hydrophilic interaction capillary electrochromatography. J Chromatogr A 2013; 1317:77-84. [PMID: 23972465 DOI: 10.1016/j.chroma.2013.07.100] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2013] [Revised: 07/23/2013] [Accepted: 07/26/2013] [Indexed: 10/26/2022]
Abstract
Novel polar monoliths were introduced for hydrophilic interaction capillary electrochromatography (HI-CEC). In one case, a neutral polar monolith resulted from the in situ polymerization of glyceryl methacrylate (GMM) and pentaerythritol triacrylate (PETA) in a ternary porogenic solvent. GMM and PETA possess hydroxyl functional groups, which impart the monolith with hydrophilic interaction sites. This monolith is designated as hydroxy monolith. Although the hydroxy monolith is neutral and void of fixed charges on the surface, a relatively strong cathodal EOF was observed due to the electric double layer formed by the adsorption of ions from the mobile phase, producing a bulk mobile phase flow. The second monolith is charged and referred to as AP-monolith that possesses amine/amide functionalities on its surface, and was prepared by the in situ polymerization of N-(3-aminopropyl) methacrylamide hydrochloride (NAPM) and ethylene dimethacrylate (EDMA) in the presence of cyclohexanol, dodecanol and methanol as porogens. Over the pH range studied a strong anodal EOF was observed. The AP-monolith was further exploited in HI-CEC by modifying its surface with neutral mono- and oligosaccharides to produce a series of the so called sugar modified AP-monoliths (SMAP-monolith), which are considered as stratified hydrophilic monoliths possessing a sub-layer of polar amine/amide groups and a top layer of sugar (a polyhydroxy top layer). The SMAP-monoliths can be viewed as a blend of both the hydroxy monolith and the AP-monolith. The polarity of the various monoliths seems to follow the order: hydroxy monolith<AP-monolith<SMAP-monolith. The novel monoliths were characterized over a wide range of elution conditions with a variety of polar solutes including phenols, substituted phenols, nucleic acid bases, nucleosides and nucleotides.
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Affiliation(s)
- Dilani N Gunasena
- Department of Chemistry, Oklahoma State University, Stillwater, OK 74078-3071, United States
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16
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Escrig-Doménech A, Ten-Doménech I, Simó-Alfonso EF, Herrero-Martínez JM. Preparation and characterization of octadecyl acrylate monoliths for capillary electrochromatography by photochemical, thermal, and chemical initiation†. J Sep Sci 2013; 36:2283-90. [DOI: 10.1002/jssc.201300288] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2013] [Revised: 04/26/2013] [Accepted: 05/02/2013] [Indexed: 11/09/2022]
Affiliation(s)
- Aarón Escrig-Doménech
- Department of Analytical Chemistry; Faculty of Chemistry; University of Valencia; 46100 Valencia Spain
| | - Isabel Ten-Doménech
- Department of Analytical Chemistry; Faculty of Chemistry; University of Valencia; 46100 Valencia Spain
| | - Ernesto F. Simó-Alfonso
- Department of Analytical Chemistry; Faculty of Chemistry; University of Valencia; 46100 Valencia Spain
| | - José M. Herrero-Martínez
- Department of Analytical Chemistry; Faculty of Chemistry; University of Valencia; 46100 Valencia Spain
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17
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Aguiar VS, Bottoli CBG. Development and characterization of hydrophobic organic monolithic columns for use in capillary electrochromatography. Microchem J 2013. [DOI: 10.1016/j.microc.2012.04.006] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
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18
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Wang X, Davis I, Liu A, Shamsi SA. Development of a CZE-ESI-MS assay with a sulfonated capillary for profiling picolinic acid and quinolinic acid formation in multienzyme system. Electrophoresis 2013; 34:1828-35. [PMID: 23576119 PMCID: PMC4153595 DOI: 10.1002/elps.201200679] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2012] [Revised: 01/26/2013] [Accepted: 01/27/2013] [Indexed: 11/08/2022]
Abstract
This article describes the development of a reliable CZE-ESI-MS method to simultaneously separate and quantitate three specific metabolites (3-hydroxyanthranilic acid (3-HAA), quinolinic acid (QA), and picolinic acid (PA)) of the kynurenine pathway (KP) of tryptophan catabolism. Using a covalently bonded sulfonated capillary, the parameters such as pH, type of background electrolyte, type of organic solvent, nebulizer pressure as well as both negative and positive ESI-MS modes were optimized to achieve the best Rs and S/N of three KP metabolites. The developed CZE-ESI-MS assay provided high resolution of PA/QA, high specificity, a total analysis time of 10 min with satisfactory intraday and interday repeatability of migration time and peak areas. Under optimized CZE-ESI-MS conditions, the calibration curves over a concentration range of 19-300 μM for 3-HAA and QA, and 75-300 μM for PA were simultaneously generated. The method was successfully applied for the first time to profile the concentrations of initial substrate, 3-HAA, and its eventual products, PA and QA, formed in the complex multienzyme system. As the ratio of two enzymes, 3-hydroxyanthranilate 3,4-dioxygenase (HAO) and α-amino-β-carboxymuconate-ε-semialdehyde decarboxylase (ACMSD) decreases, the concentration of QA approaches essentially zero indicating that all ACMS formed by the action of HAO is consumed by ACMSD rather than its spontaneous decay to QA.
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Affiliation(s)
- Xiaochun Wang
- Department of Chemistry, Center of Diagnostics and Therapeutics, Georgia State University, 50 Decatur Street, Atlanta, GA 30303, USA
| | - Ian Davis
- Department of Chemistry, Center of Diagnostics and Therapeutics, Georgia State University, 50 Decatur Street, Atlanta, GA 30303, USA
| | - Aimin Liu
- Department of Chemistry, Center of Diagnostics and Therapeutics, Georgia State University, 50 Decatur Street, Atlanta, GA 30303, USA
| | - Shahab A. Shamsi
- Department of Chemistry, Center of Diagnostics and Therapeutics, Georgia State University, 50 Decatur Street, Atlanta, GA 30303, USA
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Metal organic framework–organic polymer monolith stationary phases for capillary electrochromatography and nano-liquid chromatography. Anal Chim Acta 2013; 779:96-103. [DOI: 10.1016/j.aca.2013.03.071] [Citation(s) in RCA: 111] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2013] [Revised: 03/25/2013] [Accepted: 03/29/2013] [Indexed: 11/18/2022]
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20
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Gölgelioğlu Ç, Tuncel A. Butyl methacrylate based monoliths with different cross-linking agents using DMF-aqueous buffer as porogen. Electrophoresis 2012; 34:331-42. [DOI: 10.1002/elps.201200029] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2012] [Revised: 08/15/2012] [Accepted: 08/15/2012] [Indexed: 11/07/2022]
Affiliation(s)
- Çiğdem Gölgelioğlu
- Chemical Engineering Department; Hacettepe University; Beytepe; Ankara; Turkey
| | - Ali Tuncel
- Chemical Engineering Department; Hacettepe University; Beytepe; Ankara; Turkey
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21
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Jmeian Y, Hammad LA, Mechref Y. Fast and Efficient Online Release of N-Glycans from Glycoproteins Facilitating Liquid Chromatography–Tandem Mass Spectrometry Glycomic Profiling. Anal Chem 2012; 84:8790-6. [DOI: 10.1021/ac301855v] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Yazen Jmeian
- METACyt Biochemical Analysis Center, Department of
Chemistry, Indiana University, Bloomington,
Indiana 47405, United States
| | - Loubna A. Hammad
- METACyt Biochemical Analysis Center, Department of
Chemistry, Indiana University, Bloomington,
Indiana 47405, United States
| | - Yehia Mechref
- METACyt Biochemical Analysis Center, Department of
Chemistry, Indiana University, Bloomington,
Indiana 47405, United States
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Chen XJ, Dinh NP, Zhao J, Wang YT, Li SP, Svec F. Effect of ion adsorption on CEC separation of small molecules using hypercrosslinked porous polymer monolithic capillary columns. J Sep Sci 2012; 35:1502-5. [PMID: 22740260 DOI: 10.1002/jssc.201200138] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
Both poly(styrene-co-vinylbenzyl chloride-co-divinylbenzene) and poly(4-methylstyrene-co-vinylbenzyl chloride-co-divinylbenzene) monolithic columns have been hypercrosslinked and for the first time used to achieve capillary electrochromatographic separations. Although these columns do not contain ionizable functionalities, electroosmotic flow was observed due to adsorption of ions from a buffer solution contained in the mobile phase on the surface of the hydrophobic polymer. An increase of more than one order of magnitude was observed with the use of both monolithic polymers. The hypercrosslinking reaction creates a large surface area thus enabling adsorption of a much larger number of ions. Alkylbenzenes were successfully separated using the hypercrosslinked monolithic columns.
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Affiliation(s)
- Xiao-Jia Chen
- State Key Laboratory of Quality Research in Chinese Medicine, University of Macau, Macao SAR, P R China
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23
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Chen Z, Wang J, Chen D, Fan G, Wu Y. Sodium desoxycholate-assisted capillary electrochromatography with methacrylate ester-based monolithic column on fast separation and determination of coumarin analogs in Angelica dahurica extract. Electrophoresis 2012; 33:2884-91. [PMID: 22930555 DOI: 10.1002/elps.201200120] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2012] [Revised: 05/11/2012] [Accepted: 05/14/2012] [Indexed: 11/11/2022]
Abstract
A rapid and sensitive CEC method with methacrylate ester-based monolithic column has been developed for separation and determination of five coumarins (byakangelicin, oxypeucedanin hydrate, xanthotoxol, 5-hydroxy-8-methoxypsoralen and bergapten) in Angelica dahurica extract. Surfactant sodium desoxycholate (SDC) was introduced into the mobile phase as the pseudostationary to dynamically increase the selectivity of analytes instead of increasing the hydrophobicity of stationary phase. In addition, other factors, pH of phosphate buffer, ACN content and applied voltage, for instance, have also an obvious effect on the resolution but little on the retention time. Satisfactory separation of these five coumarins was achieved within 6 min under a 30:70 v/v ACN-buffer containing 20 mM sodium dihydrogen phosphate (NaH(2) PO(4) ) and 0.25 mM SDC at pH 2.51. The RSDs of intraday and interday for relative peak areas were less than 3.0% and 4.7%, respectively; and the recoveries were between 87.5% and 95.0%. The LODs were lower than 0.15 μg/mL and the LOQs were lower than 0.30 μg/mL, respectively, while calibration curves showed a good linearity (r(2) > 0.9979). Finally, five target coumarins from the crude extracts of A. dahurica were separated, purified, and concentrated by D-101 macroporous resin, and were successfully separated and quantitatively determined within 6 min.
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Affiliation(s)
- Zhao Chen
- Department of Pharmaceutical Analysis, Second Military Medical University, Shanghai, People's Republic of China. cz04101103@ hotmail.com
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He J, Wang X, Morill M, Shamsi SA. Amino acid bound surfactants: a new synthetic family of polymeric monoliths opening up possibilities for chiral separations in capillary electrochromatography. Anal Chem 2012; 84:5236-42. [PMID: 22607448 DOI: 10.1021/ac300944z] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
By combining a novel chiral amino-acid surfactant containing an acryloyl amide tail, a carbamate linker, and a leucine headgroup of different chain lengths with a conventional cross-linker and a polymerization technique, a new "one-pot" synthesis for the generation of amino-acid based polymeric monolith is realized. The method promises to open up the discovery of an amino-acid based polymeric monolith for chiral separations in capillary electrochromatography (CEC). The possibility of enhanced chemoselectivity for simultaneous separation of ephedrine and pseudoephedrine containing multiple chiral centers and the potential use of this amino-acid surfactant bound column for CEC and CEC coupled to mass spectrometric detection are demonstrated.
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Affiliation(s)
- Jun He
- Center of Diagnostics and Therapeutics, Georgia State University, 50 Decatur Street, Atlanta, Georgia 30303, USA
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25
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Puangpila C, Nhujak T, Rassi ZE. Investigation of neutral monolithic capillary columns with varying n-alkyl chain lengths in capillary electrochromatography. Electrophoresis 2012; 33:1431-42. [DOI: 10.1002/elps.201200018] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Affiliation(s)
| | - Thumnoon Nhujak
- Chromatography and Separation Research Unit; Department of Chemistry; Faculty of Science; Chulalongkorn University; Bangkok; Thailand
| | - Ziad El Rassi
- Department of Chemistry; Oklahoma State University; OKlahoma
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26
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Li Y, Aggarwal P, Tolley H, Lee M. Organic Monolith Column Technology for Capillary Liquid Chromatography. ADVANCES IN CHROMATOGRAPHY 2012; 50:237-80. [DOI: 10.1201/b11636-6] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/18/2023]
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27
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Micellar liquid chromatographic determination of carbaryl and 1-naphthol in water, soil, and vegetables. Int J Anal Chem 2012; 2012:809513. [PMID: 22505922 PMCID: PMC3296199 DOI: 10.1155/2012/809513] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2011] [Accepted: 10/27/2011] [Indexed: 11/17/2022] Open
Abstract
A liquid chromatographic procedure has been developed for the determination of carbaryl, a phenyl-N-methylcarbamate, and its main metabolite 1-naphthol, using a C18 column (250 mm × 4.6 mm) with a micellar mobile phase and fluorescence detection at maximum excitation/emission wavelengths of 225/333 nm, respectively. In the optimization step, surfactants sodium dodecyl sulphate (SDS), Brij-35 and N-cetylpyridinium chloride monohydrate, and organic solvents propanol, butanol, and pentanol were considered. The selected mobile phase was 0.15 M SDS-6% (v/v)-pentanol-0.01 M NaH2PO4 buffered at pH 3. Validation studies, according to the ICH Tripartite Guideline, included linearity (r > 0.999), limit of detection (5 and 18 ng mL−1, for carbaryl and 1-naphthol, resp.), and limit of quantification (15 and 50 ng mL−1, for carbaryl and 1-naphthol, resp.), with intra- and interday precisions below 1%, and robustness parameters below 3%. The results show that the procedure was adequate for the routine analysis of these two compounds in water, soil, and vegetables samples.
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Esteve-Romero J, Marco-Peiro S, Rambla-Alegre M, Durgbanshi A, Bose D, Mourya SK. A MICELLAR LIQUID CHROMATOGRAPHIC METHOD FOR THE DETERMINATION OF CARBARYL AND 1-NAPHTHOL IN BIOLOGICAL SAMPLES. J LIQ CHROMATOGR R T 2012. [DOI: 10.1080/10826076.2011.601489] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/14/2022]
Affiliation(s)
- Josep Esteve-Romero
- a Bioanalytical Chemistry, QFA, ESTCE, Universitat Jaume I , Castelló , Spain
| | - Sergio Marco-Peiro
- a Bioanalytical Chemistry, QFA, ESTCE, Universitat Jaume I , Castelló , Spain
| | - Maria Rambla-Alegre
- a Bioanalytical Chemistry, QFA, ESTCE, Universitat Jaume I , Castelló , Spain
| | - Abhilasha Durgbanshi
- b Department of Applied Chemistry, IT , Banaras Hindu University , Varanasi , India
| | - Devasish Bose
- c Department of Criminology and Forensic Sciences , Dr. H.S.Gour University , Sagar , India
| | - Sandeep K. Mourya
- c Department of Criminology and Forensic Sciences , Dr. H.S.Gour University , Sagar , India
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29
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Karenga S, El Rassi Z. A novel, neutral hydroxylated octadecyl acrylate monolith with fast electroosmotic flow velocity and its application to the separation of various solutes including peptides and proteins in the absence of electrostatic interactions. Electrophoresis 2012; 31:3192-9. [PMID: 22216430 DOI: 10.1002/elps.201000360] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
A neutral hydroxylated octadecyl monolith (ODM-OH) for reversed-phase capillary electrochromatography has been developed. The ODM-OH was prepared by the in situ polymerization of octadecyl acrylate and pentaerythritol triacrylate (PETA) in a ternary porogenic solvent. Pentaerythritol triacrylate possesses a hydroxyl functional group, which imparts the monolith with a hydrophilic group, thus the acronym ODM-OH. The ODM-OH column exhibited cathodal EOF over a wide range of pH and ACN concentration in the mobile phase despite the fact that it was devoid of any fixed charges. This ODM-OH monolith exhibited stronger EOF than its counterpart the ODM made from the in situ polymerization of octadecyl acrylate and trimethylolpropane trimethacrylate. Similar to ODM, it is believed that the EOF was due to the adsorption of ions from the mobile phase onto the surface of the monolith thus imparting the neutral monolithic column the zeta potential necessary to support the EOF. The higher EOF exhibited by ODM-OH was due to the presence of polar OH groups on its surface, which would favor stronger adsorption of ions from the mobile phase. The wide applications of the neutral ODM-OH column were demonstrated in the separation of a wide range of small and large solutes. As a typical result, the ODM-OH was able to separate proteins quite rapidly yielding 200,000 plates/m.
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Affiliation(s)
- Samuel Karenga
- Department of Chemistry, Oklahoma State University, Stillwater, OK 74075, USA
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30
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Novel highly hydrophilic methacrylate-based monolithic column with mixed-mode of hydrophilic and strong cation-exchange interactions for pressurized capillary electrochromatography. J Chromatogr A 2011; 1218:4671-7. [DOI: 10.1016/j.chroma.2011.05.052] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2011] [Revised: 04/28/2011] [Accepted: 05/14/2011] [Indexed: 11/23/2022]
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31
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Preparation and Evaluation of Long Chain Alkyl Methacrylate Monoliths for Capillary Chromatography. Chromatographia 2011. [DOI: 10.1007/s10337-011-2047-x] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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32
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Karenga S, El Rassi Z. Controlling retention, selectivity and magnitude of EOF by segmented monolithic columns consisting of octadecyl and naphthyl monolithic segments--applications to RP-CEC of both neutral and charged solutes. Electrophoresis 2011; 32:1033-43. [PMID: 21455910 DOI: 10.1002/elps.201000563] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2010] [Revised: 11/22/2010] [Accepted: 11/30/2010] [Indexed: 11/12/2022]
Abstract
Monolithic capillaries made of two adjoining segments each filled with a different monolith were introduced for the control and manipulation of the electroosmotic flow (EOF), retention and selectivity in reversed phase-capillary electrochromatography (RP-CEC). These columns were called segmented monolithic columns (SMCs) where one segment was filled with a naphthyl methacrylate monolith (NMM) to provide hydrophobic and π-interactions, while the other segment was filled with an octadecyl acrylate monolith (ODM) to provide solely hydrophobic interaction. The ODM segment not only provided hydrophobic interactions but also functioned as the EOF accelerator segment. The average EOF of the SMC increased linearly with increasing the fractional length of the ODM segment. The neutral SMC provided a convenient way for tuning EOF, selectivity and retention in the absence of annoying electrostatic interactions and irreversible solute adsorption. The SMCs allowed the separation of a wide range of neutral solutes including polycyclic aromatic hydrocarbons (PAHs) that are difficult to separate using conventional alkyl-bonded stationary phases. In all cases, the k' of a given solute was a linear function of the fractional length of the ODM or NMM segment in the SMCs, thus facilitating the tailoring of a given SMC to solve a given separation problem. At some ODM fractional length, the fabricated SMC allowed the separation of charged solutes such as peptides and proteins that could not otherwise be achieved on a monolithic column made from NMM as an isotropic stationary phase due to the lower EOF exhibited by this monolith.
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Affiliation(s)
- Samuel Karenga
- Department of Chemistry, Oklahoma State University, Stillwater, OK 74075, USA
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33
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Hu J, Yin L, Jia L. Chitosan-silica hybrid-coated open tubular column for hydrophilic interaction capillary electrochromatography. J Sep Sci 2011; 34:565-73. [PMID: 21265018 DOI: 10.1002/jssc.201000688] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2010] [Revised: 12/06/2010] [Accepted: 12/08/2010] [Indexed: 11/08/2022]
Abstract
A novel and convenient protocol for the preparation of an open-tubular column coated with chitosan-silica hybrid using chitosan and silane-coupling agent (γ-glycidoxy-propyltrimethoxysilane) was developed for CEC, in which, chitosan was covalently bonded to the inner wall of a fused-silica capillary using γ-glycidoxy-propyltrimethoxysilane as a cross-linking agent. The stationary phase was hydrophilic due to the chitosan-silica hybrid with abundant amine and hydroxyl functional groups. The chromatographic characteristics of the column were evaluated by the separation of some organic acids and inorganic anions. The column showed good selectivity for nucleotides, aromatic acids, and inorganic anions. The mechanism for the separation of these compounds was primarily based on the hydrophilic and electrostatic interactions combined with the electrophoretic mechanism. The CEC method on the column for the separation of these compounds was compared with CE method in a bare capillary.
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Affiliation(s)
- Jinmei Hu
- Ministry of Education Key Laboratory of Laser Life Science & Institute of Laser Life Science, College of Biophotonics, South China Normal University, Guangzhou, PR China
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34
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Analyses of non-steroidal anti-inflammatory drugs by on-line concentration capillary electrochromatography using poly(stearyl methacrylate–divinylbenzene) monolithic columns. J Chromatogr A 2011; 1218:350-8. [DOI: 10.1016/j.chroma.2010.11.040] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2010] [Revised: 11/16/2010] [Accepted: 11/18/2010] [Indexed: 11/23/2022]
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35
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Karenga S, El Rassi Z. Trends in nonpolar polymer-based monolithic columns for reversed-phase capillary electrochromatography. Electrophoresis 2010; 32:90-104. [PMID: 21171116 DOI: 10.1002/elps.201000490] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2010] [Revised: 09/30/2010] [Accepted: 10/05/2010] [Indexed: 11/11/2022]
Abstract
This review article is concerned with describing the various strategies that have been introduced for the preparation of nonpolar polymer-based monolithic columns for RP-CEC. First, the various traditional ways of generating the EOF that involved the introduction of fixed charges on the surface of the monoliths are reviewed. This is followed by a description of the development of neutral monoliths as the most promising monoliths for the separation of a wide range of neutral and charged species at a relatively moderate to strong EOF in the absence of electrostatic attraction or repulsion.
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Affiliation(s)
- Samuel Karenga
- Department of Chemistry, Oklahoma State University, Stillwater, OK, USA
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36
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Huang HY, Cheng YJ, Liu WL, Hsu YF, Lee S. Poly(divinylbenzene-alkyl methacrylate) monolithic stationary phases in capillary electrochromatography. J Chromatogr A 2010; 1217:5839-47. [DOI: 10.1016/j.chroma.2010.07.050] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2010] [Revised: 07/15/2010] [Accepted: 07/17/2010] [Indexed: 12/01/2022]
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37
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Cao Q, Xu Y, Liu F, Svec F, Fréchet JMJ. Polymer Monoliths with Exchangeable Chemistries: Use of Gold Nanoparticles As Intermediate Ligands for Capillary Columns with Varying Surface Functionalities. Anal Chem 2010; 82:7416-21. [DOI: 10.1021/ac1015613] [Citation(s) in RCA: 139] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Qing Cao
- College of Chemistry, University of California, Berkeley, California 94720-1460, The Molecular Foundry, E.O. Lawrence Berkeley National Laboratory, Berkeley, California 94720-8139, and Beijing National Laboratory for Molecular Sciences, Key Laboratory of Bioorganic Chemistry and Molecular Engineering of Ministry of Education, College of Chemistry, Peking University, Beijing 100871, China
| | - Yan Xu
- College of Chemistry, University of California, Berkeley, California 94720-1460, The Molecular Foundry, E.O. Lawrence Berkeley National Laboratory, Berkeley, California 94720-8139, and Beijing National Laboratory for Molecular Sciences, Key Laboratory of Bioorganic Chemistry and Molecular Engineering of Ministry of Education, College of Chemistry, Peking University, Beijing 100871, China
| | - Feng Liu
- College of Chemistry, University of California, Berkeley, California 94720-1460, The Molecular Foundry, E.O. Lawrence Berkeley National Laboratory, Berkeley, California 94720-8139, and Beijing National Laboratory for Molecular Sciences, Key Laboratory of Bioorganic Chemistry and Molecular Engineering of Ministry of Education, College of Chemistry, Peking University, Beijing 100871, China
| | - Frantisek Svec
- College of Chemistry, University of California, Berkeley, California 94720-1460, The Molecular Foundry, E.O. Lawrence Berkeley National Laboratory, Berkeley, California 94720-8139, and Beijing National Laboratory for Molecular Sciences, Key Laboratory of Bioorganic Chemistry and Molecular Engineering of Ministry of Education, College of Chemistry, Peking University, Beijing 100871, China
| | - Jean M. J. Fréchet
- College of Chemistry, University of California, Berkeley, California 94720-1460, The Molecular Foundry, E.O. Lawrence Berkeley National Laboratory, Berkeley, California 94720-8139, and Beijing National Laboratory for Molecular Sciences, Key Laboratory of Bioorganic Chemistry and Molecular Engineering of Ministry of Education, College of Chemistry, Peking University, Beijing 100871, China
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38
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Liao S, Wang X, Lin X, Xie Z. Preparation and characterization of a molecularly imprinted monolithic column for pressure-assisted CEC separation of nitroimidazole drugs. Electrophoresis 2010; 31:2822-30. [DOI: 10.1002/elps.201000035] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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39
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Karenga S, El Rassi Z. Naphthyl methacrylate-based monolithic column for RP-CEC via hydrophobic and pi interactions. Electrophoresis 2010; 31:991-1002. [PMID: 20148404 DOI: 10.1002/elps.200900700] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
A neutral naphthyl methacrylate-based monolith (NMM) was introduced for RP-CEC of various aromatic compounds via hydrophobic and pi interactions. It was characterized over a wide range of elution conditions to gain insight into its RP retention mechanism toward the various solute probes under investigation. First, the NMM column exhibited cathodal EOF at various mobile phase compositions and pH suggesting that although the NMM column is void of fixed charges, it acquires a negative zeta potential. It is believed that the negative zeta potential is imparted by the adsorption of mobile phase ions to the NMM surface. The NMM column exhibited pi-pi interactions in addition to hydrophobic interactions due to the aromatic and nonpolar nature of its naphthyl ligands. In all cases, the retention of the various aromatic test solutes including PAHs, benzene derivatives, toluene derivatives, anilines and toluidine, tolunitrile and nitrotoluene positional isomers on the NMM column were compared to their retention on an octadecyl acrylate-based monolithic column. Not only were the values of the retention factors of the various solutes on the NMM column higher than those obtained on the octadecyl acrylate-based monolithic column under otherwise the same CEC conditions, but the elution orders were also different on both columns with a superior and unique selectivity exhibited by the NMM column.
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Affiliation(s)
- Samuel Karenga
- Department of Chemistry, Oklahoma State University, Stillwater, OK 74075, USA
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40
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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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41
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Liu S, Lin X, Zhang X, Lü H, Xie Z. Off-Column Amperometric Detection for Pressurized Capillary Electrochromatography. Chromatographia 2010. [DOI: 10.1365/s10337-010-1529-6] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
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42
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Svec F. Porous polymer monoliths: amazingly wide variety of techniques enabling their preparation. J Chromatogr A 2010; 1217:902-24. [PMID: 19828151 PMCID: PMC2829304 DOI: 10.1016/j.chroma.2009.09.073] [Citation(s) in RCA: 423] [Impact Index Per Article: 30.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2009] [Revised: 09/11/2009] [Accepted: 09/28/2009] [Indexed: 10/20/2022]
Abstract
The porous polymer monoliths went a long way since their invention two decades ago. While the first studies applied the traditional polymerization processes at that time well established for the preparation of polymer particles, creativity of scientists interested in the monolithic structures has later led to the use of numerous less common techniques. This review article presents vast variety of methods that have meanwhile emerged. The text first briefly describes the early approaches used for the preparation of monoliths comprising standard free radical polymerizations and includes their development up to present days. Specific attention is paid to the effects of process variables on the formation of both porous structure and pore surface chemistry. Specific attention is also devoted to the use of photopolymerization. Then, several less common free radical polymerization techniques are presented in more detail such as those initiated by gamma-rays and electron beam, the preparation of monoliths from high internal phase emulsions, and cryogels. Living processes including stable free radicals, atom transfer radical polymerization, and ring-opening metathesis polymerization are also discussed. The review ends with description of preparation methods based on polycondensation and polyaddition reactions as well as on precipitation of preformed polymers affording the monolithic materials.
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Affiliation(s)
- Frantisek Svec
- The Molecular Foundry, E. O. Lawrence Berkeley National Laboratory, MS 67R6110, Berkeley, CA 94720-8139, USA.
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43
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Lin CL, Cheng YJ, Huang HY, Lee S. Analyses of sulfonamide antibiotics by CEC using poly(divinylbenzene-1-octadecene-vinylbenzyl trimethyl ammonium chloride) monolithic columns. Electrophoresis 2009; 30:3828-37. [DOI: 10.1002/elps.200900386] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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44
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Greiderer A, Ligon SC, Huck CW, Bonn GK. Monolithic poly(1,2-bis(p-vinylphenyl)ethane) capillary columns for simultaneous separation of low- and high-molecular-weight compounds. J Sep Sci 2009; 32:2510-20. [PMID: 19598164 DOI: 10.1002/jssc.200900211] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Monolithic poly(1,2-bis(p-vinylphenyl)ethane (BVPE)) capillary columns were prepared by thermally initiated free radical polymerisation of 1,2-bis(p-vinylphenyl)ethane in the presence of inert diluents (porogens) and alpha,alpha'-azoisobutyronitrile (AIBN) as initiator. Polymerisations were accomplished in 200 microm ID fused silica capillaries at 65 degrees C and for 60 min. Mercury intrusion porosimetry measurements of the polymeric RP support showed a broad bimodal pore-size-distribution of mesopores and small macropores in the range of 5-400 nm and flow-channels in the mum range. N(2)-adsorption (BET) analysis resulted in a tremendous enhancement of surface area (101 m(2)/g) of BVPE stationary phases compared to typical organic monoliths (approximately 20 m(2)/g), indicating the presence of a considerable amount of mesopores. Consequently, the adequate proportion of both meso- and (small) macropores allowed the rapid and high-resolution separation of low-molecular-weight compounds as well as biomolecules on the same monolithic support. At the same time, the high fraction of flow-channels provided enhanced column permeability. The chromatographic performance of poly(1,2-bis(p-vinylphenyl)ethane) capillary columns for the separation of biomolecules (proteins, oligonucleotides) and small molecules (alkyl benzenes, phenols, phenons) are demonstrated in this article. Additionally, pressure drop versus flow rate measurements of novel poly(1,2-bis(p-vinylphenyl)ethane) capillary columns confirmed high mechanical robustness, low swelling in organic solvents and high permeability. Due to the simplicity of monolith fabrication, comprehensive studies of the retention and separation behaviour of monolithic BVPE columns resulted in high run-to-run and batch-to-batch reproducibilities. All these attributes prove the excellent applicability of monolithic poly(1,2-bis(p-vinylphenyl)ethane) capillary columns for micro-HPLC towards a huge range of analytes of different chemistries and molecular sizes.
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Affiliation(s)
- Andreas Greiderer
- Institute of Analytical Chemistry and Radiochemistry, University of Innsbruck, 6020 Innsbruck, Austria
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45
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Study of peak shape and efficiency in butyl acrylate-based monolithic columns for capillary electrochromatography. J Chromatogr A 2009; 1216:6831-7. [DOI: 10.1016/j.chroma.2009.08.016] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2009] [Revised: 06/09/2009] [Accepted: 08/07/2009] [Indexed: 11/18/2022]
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46
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Lu M, Feng Q, Lu Q, Cai Z, Zhang L, Chen G. Preparation and evaluation of the highly cross-linked poly(1-hexadecane-co-trimethylolpropane trimethacrylate) monolithic column for capillary electrochromatography. Electrophoresis 2009; 30:3540-7. [DOI: 10.1002/elps.200900018] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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47
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Svec F. CEC: selected developments that caught my eye since the year 2000. Electrophoresis 2009; 30 Suppl 1:S68-82. [PMID: 19517503 DOI: 10.1002/elps.200900062] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
During the last decade, a number of new developments have emerged in the field of CEC. This paper focuses only on monolithic columns prepared from synthetic polymers. Monolithic columns have become a well-established format of stationary phases for CEC immediately after their inception in the mid-1990s. They are readily prepared in situ from liquid precursors. Also, the control over both porous properties and surface chemistries is easy to achieve. These advantages make the monolithic separation media an attractive alternative to capillary columns packed with particulate materials. Since the number of papers concerned with just this single topic of polymer-based monolithic CEC columns is large, this overview describes only those approaches this author found interesting.
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Affiliation(s)
- Frantisek Svec
- The Molecular Foundry, E. O. Lawrence Berkeley National Laboratory, Berkeley, CA 94720-8197, USA.
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48
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Wang X, Lin X, Xie Z. Preparation and evaluation of a sulfoalkylbetaine-based zwitterionic monolithic column for CEC of polar analytes. Electrophoresis 2009; 30:2702-10. [DOI: 10.1002/elps.200900006] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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49
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Lu M, Zhang L, Lu Q, Chi Y, Chen G. Rapid analysis of peptides and amino acids by CE-ESI-MS using chemically modified fused-silica capillaries. Electrophoresis 2009; 30:2273-9. [DOI: 10.1002/elps.200800683] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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50
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Preparation and evaluation of a neutral methacrylate-based monolithic column for hydrophilic interaction stationary phase by pressurized capillary electrochromatography. J Chromatogr A 2009; 1216:4611-7. [DOI: 10.1016/j.chroma.2009.03.057] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2008] [Revised: 01/05/2009] [Accepted: 03/20/2009] [Indexed: 11/20/2022]
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