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Macktuf MAA, Rutan SC, Bautista J, Collinson MM. Continuous stationary phase gradient preparation on planar chromatographic media using vapor phase deposition of silane. J Chromatogr A 2024; 1730:465090. [PMID: 38955129 DOI: 10.1016/j.chroma.2024.465090] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2024] [Revised: 06/11/2024] [Accepted: 06/12/2024] [Indexed: 07/04/2024]
Abstract
A new, versatile, and straightforward vapor phase deposition (VPD) approach was used to prepare continuous stationary phase gradients (cSPGs) on silica thin-layer chromatography (TLC) plates using phenyldimethylchlorosilane (PDCS) as a precursor. A mixture of paraffin oil and PDCS was placed at the bottom of an open-ended rectangular chamber, allowing the reactive silanes to evaporate and freely diffuse under a controlled atmosphere. As the volatile silane diffused across the length of the TLC plate, it reacted with the surface silanol groups thus functionalizing the surface in a gradient fashion. Characterization of the gradient TLC plates was done through UV visualization and diffuse reflectance spectroscopy (DRS). Visualizing the fluorescent gradient plates under UV radiation shows the clear presence of a gradient with the side closest to the vapor source undergoing the most modification. More quantitative characterization of the shape of the gradient was provided by DRS. The DRS showed that the degree of modification and shape of the gradient was dependent on the concentration of silane, VPD time, and relative humidity. To evaluate the chromatographic performance, a mixture of three aromatic compounds (acetaminophen (A), aspirin (As), and 3-hydroxy-2-naphthoic acid (3H)) was spotted on the high (GHP) and low phenyl (GLP) ends of the gradient TLC plates and the results compared to the separations carried out on unmodified and uniformly modified plates. The GHP TLC plates showed retention factors (Rf) of 0.060 ± 0.006, 0.391 ± 0.006, and 0.544 ± 0.006, whereas the unmodified plate displayed Rf values of 0.059 ± 0.006, 0.092 ± 0.003, and 0.037 ± 0.002 for the analytes A, As, and 3H, respectively. From the Rf values, it was observed that each modified plate exhibited different selectivity for the analytes. The GHP TLC plates exhibited better separation performance, and improved resolution compared to the GLP, unmodified, and uniformly modified plates. Overall, VPD is a new, cost-effective method for creating a gradient on the stationary phase which has the potential to advance chromatographic separation capabilities.
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Affiliation(s)
| | - Sarah C Rutan
- Department of Chemistry, Virginia Commonwealth University, Richmond, VA 23284, USA
| | - Judith Bautista
- Dow Chemical, 230 Abner Jackson Pkwy, Lake Jackson, TX 77566, USA
| | - Maryanne M Collinson
- Department of Chemistry, Virginia Commonwealth University, Richmond, VA 23284, USA.
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2
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Fekete S, Lauber M, Xu M. Considering the selectivity of pore size gradient size exclusion chromatography columns. J Chromatogr A 2024; 1718:464726. [PMID: 38354505 DOI: 10.1016/j.chroma.2024.464726] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2023] [Revised: 01/25/2024] [Accepted: 02/07/2024] [Indexed: 02/16/2024]
Abstract
One of the most significant performance determining variables of a size exclusion column is the pore size of its packing material. This is most definitely the case for assigning the suitability of a given column for differently sized analytes. As technologies for particle and column manufacturing continue to advance, it is worth contemplating the value of more finely controlled manipulation of this parameter. The change in a packing material's pores across the length of a size exclusion column was thus explored. A change in average pore diameter and pore size distribution was studied by means of theoretical modeling. These parameters were investigated for independent and combinatorial effects. From our predictions, versus tandem column chromatography, a gradient column apparatus does not yield sizable increases in monomer to dimer selectivity of any given critical pair. Instead, our modeling suggests it can yield more universally effective separations of multiple pairs of species at once, as is sometimes necessary when analyzing the high molecular weight components of highly aggregated drug substances.
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Affiliation(s)
- Szabolcs Fekete
- Waters Corporation, located in CMU-Rue Michel Servet 1, 1211 Geneva 4, Switzerland.
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3
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Study of Efficiency of Capacity Gradient Ion-Exchange Stationary Phases. SEPARATIONS 2022. [DOI: 10.3390/separations10010014] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
Highly efficient columns are necessary for the modern analytical applications of liquid chromatography. In this work, the separation efficiency of ion-exchange capacity gradient stationary phases combined with eluent concentration gradient was studied by a theoretical approach. In the course of our work three different scenarios of capacity gradients were used with different shapes (linear, convex and concave). The resolutions of different gradient columns were calculated for each scenario. As a reference, a uniform column was considered, which had the same analysis time as the non-uniform column. In the case of separation of ions with same charges, the gradient column offered only a marginal advantage compared to the uniform column due to the bandwidth compression caused by the capacity gradient. In the case of ions with different charges, however, the advantage of the gradient column was more significant. This was mainly due to the increased retention time difference of solutes. Ion-exchange capacity gradient columns may be a new way to separate ions more efficiently.
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4
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Fekete S, Lauber M. Studying the possibilities of dual stationary phase gradients to explore alternative selectivities in liquid chromatography. J Chromatogr A 2022; 1681:463492. [PMID: 36116368 DOI: 10.1016/j.chroma.2022.463492] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2022] [Revised: 09/05/2022] [Accepted: 09/07/2022] [Indexed: 11/25/2022]
Abstract
Previous studies on stationary phase gradients have inspired a new phase of theoretical work and an expansion of the concept to include multiple retention mechanisms. The theoretical work presented here corroborates previous reports that a stationary phase gradient can produce selectivity in a separation as effectively as careful adjustments to a mobile phase gradient program, especially when such column is operated in mobile phase gradient elution mode. In reality, no column is singularly based on one type of interaction mechanism, and many columns are nowadays designed to solicit multiple solute to stationary phase interactions. These mixed-mode columns inspired us to give more careful consideration to the idea of dual stationary phase gradients. With the theory applied here, it is suggested that the modulation of two unique interaction mechanisms across a chromatographic column has the potential to open up previously unseen selectivities. With the increasing prevalence of mixed-mode columns, we believe there will be ample opportunity to explore these new concepts in experimental work.
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Affiliation(s)
- Szabolcs Fekete
- Waters Corporation, located in CMU-Rue Michel Servet 1, 1211 Geneva 4, Switzerland.
| | - Matthew Lauber
- Waters Corporation, 34 Maple Street, Milford, MA 01757, United States
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5
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6
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Pohl CA. Preparation of ion exchange columns with longitudinal stationary phase gradients. Heliyon 2021; 7:e06961. [PMID: 34027168 PMCID: PMC8129947 DOI: 10.1016/j.heliyon.2021.e06961] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2021] [Revised: 02/28/2021] [Accepted: 04/25/2021] [Indexed: 11/18/2022] Open
Abstract
Preparation of columns using electrostatic attachment of anion exchange latex particles with charge density gradients is demonstrated. When such columns are oriented with the highest charge density at the column outlet, the chromatographic performance at low linear velocity is enhanced. When multiple successive charge density gradients are prepared along the length of the column with the highest capacity oriented at the inlet end of the column, significant improvement in chromatographic performance is observed during gradient elution chromatography.
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7
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Lequieu J, Magenau AJD. Reaction-induced phase transitions with block copolymers in solution and bulk. Polym Chem 2021. [DOI: 10.1039/d0py00722f] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Reaction-induced phase transitions use chemical reactions to drive macromolecular organisation and self-assembly. This review highlights significant and recent advancements in this burgeoning field.
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Affiliation(s)
- Joshua Lequieu
- Department of Chemical and Biological Engineering
- Drexel University
- Philadelphia
- USA
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8
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Cain CN, Weatherbee SL, Forzano AV, Rutan SC, Collinson MM. Fabrication and Characterization of a Reversed-Phase/Strong Cation Exchange Stationary Phase Gradient. J Chromatogr A 2020; 1623:461177. [DOI: 10.1016/j.chroma.2020.461177] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2020] [Revised: 04/24/2020] [Accepted: 04/27/2020] [Indexed: 10/24/2022]
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9
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Ma M, Du Y, Yang J, Feng Z, Ding W, Chen C. Gold nanoparticles-functionalized monolithic column for enantioseparation of eight basic chiral drugs by capillary electrochromatography. Mikrochim Acta 2020; 187:178. [PMID: 32076848 DOI: 10.1007/s00604-020-4144-8] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2019] [Accepted: 01/24/2020] [Indexed: 10/25/2022]
Abstract
Poly(glycidyl methacrylate)-co-(ethylene dimethacrylate) [poly(GMA-co-EDMA)] monoliths were prepared, and used as a support to attach gold nanoparticles (AuNP) via Au-S bond. Pepsin, acting as a chiral selector, was linked to the surface of the carboxyl-modified AuNP through a hydrochloride/N-hydroxysuccinimide coupling reaction. The material was characterized by scanning electron microscopy, energy dispersive X-ray spectrometry, transmission electron microscopy, thermogravimetric analysis, Fourier transform infrared spectroscopy and N2 adsorption-desorption isotherm. The pepsin@AuNP@poly(GMA-co-EDMA) monolith showed preferable enantioselectivity for hydroxychloroquine (HCQ), chloroquine (CHQ), hydroxyzine (HXY), labetalol (LAB), nefopam (NEF), clenbuterol (CLE), amlodipine (AML) and chlorpheniramine (CHL) in capillary electrochromatography (CEC). These racemic drugs were monitored at the maximum absorption wavelength (220 nm for HXQ, CHQ, HXY, LAB, NEF; 240 nm for AML; 215 nm for CLE, CHL). In comparison with the pepsin@poly(GMA-co-EDMA) monolith loaded with 5 nm AuNP, the pepsin@poly(GMA-co-EDMA) monolith loaded with 13 nm AuNP shows significantly enhanced enantiomeric resolution (HCQ: 0.62 → 3.45; CHQ: 0.60 → 2.11; HXY: 0.49 → 2.30; LAB: 1.03 → 2.45, 1.45 → 3.46, 0 → 0.67; NEF: 0.53 → 1.29; CLE: 0.42 → 0.56; AML: 0 → 0.83; CHL: 0.24 → 0.55). Pepsin concentration, buffer pH value, buffer concentration and applied voltage were investigated in detail with (±) HCQ and (±) HXY as model analytes. The reproducibility of intra-day, inter-day and column-to-column were explored, and found to be satisfactory. Graphical abstractSchematic presentation of the preparation of gold nanoparticles (AuNP) modified.
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Affiliation(s)
- Mingxuan Ma
- Key Laboratory of Drug Quality Control and Pharmacovigilance (Ministry of Education), China Pharmaceutical University, No.24 Tongjiaxiang, Nanjing, Jiangsu, 210009, People's Republic of China.,State Key Laboratory of Natural Medicines, China Pharmaceutical University, No.24 Tongjiaxiang, Nanjing, Jiangsu, 210009, People's Republic of China
| | - Yingxiang Du
- Key Laboratory of Drug Quality Control and Pharmacovigilance (Ministry of Education), China Pharmaceutical University, No.24 Tongjiaxiang, Nanjing, Jiangsu, 210009, People's Republic of China. .,State Key Laboratory of Natural Medicines, China Pharmaceutical University, No.24 Tongjiaxiang, Nanjing, Jiangsu, 210009, People's Republic of China.
| | - Jiangxia Yang
- Key Laboratory of Drug Quality Control and Pharmacovigilance (Ministry of Education), China Pharmaceutical University, No.24 Tongjiaxiang, Nanjing, Jiangsu, 210009, People's Republic of China.,State Key Laboratory of Natural Medicines, China Pharmaceutical University, No.24 Tongjiaxiang, Nanjing, Jiangsu, 210009, People's Republic of China
| | - Zijie Feng
- Key Laboratory of Drug Quality Control and Pharmacovigilance (Ministry of Education), China Pharmaceutical University, No.24 Tongjiaxiang, Nanjing, Jiangsu, 210009, People's Republic of China.,State Key Laboratory of Natural Medicines, China Pharmaceutical University, No.24 Tongjiaxiang, Nanjing, Jiangsu, 210009, People's Republic of China
| | - Wen Ding
- Key Laboratory of Drug Quality Control and Pharmacovigilance (Ministry of Education), China Pharmaceutical University, No.24 Tongjiaxiang, Nanjing, Jiangsu, 210009, People's Republic of China.,State Key Laboratory of Natural Medicines, China Pharmaceutical University, No.24 Tongjiaxiang, Nanjing, Jiangsu, 210009, People's Republic of China
| | - Cheng Chen
- Key Laboratory of Drug Quality Control and Pharmacovigilance (Ministry of Education), China Pharmaceutical University, No.24 Tongjiaxiang, Nanjing, Jiangsu, 210009, People's Republic of China.,State Key Laboratory of Natural Medicines, China Pharmaceutical University, No.24 Tongjiaxiang, Nanjing, Jiangsu, 210009, People's Republic of China
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10
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Codesido S, Rudaz S, Veuthey JL, Guillarme D, Desmet G, Fekete S. Impact of particle size gradients on the apparent efficiency of chromatographic columns. J Chromatogr A 2019; 1603:208-215. [DOI: 10.1016/j.chroma.2019.06.048] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2019] [Revised: 06/24/2019] [Accepted: 06/24/2019] [Indexed: 10/26/2022]
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11
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Komendová M, Ribeiro LF, Urban J. Controlling selectivity of polymer-based monolithic stationary phases. J Sep Sci 2019; 42:952-961. [PMID: 30576067 DOI: 10.1002/jssc.201801046] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2018] [Revised: 12/13/2018] [Accepted: 12/14/2018] [Indexed: 12/27/2022]
Abstract
In this work, we aimed to prepare a monolithic capillary column that allowed an isocratic separation of ten dopamine precursors and metabolites in a single run. Segments of five zwitterion sulfobetaine polymer monoliths have been modified by zwitterion phoshorylcholine by using an ultraviolet-initiated two-step photografting. Columns with 0, 33, 50, 66, and 100% of modified length were prepared. Effect of length of the modified segment and mobile phase composition has been tested. All columns provided dual-retention mechanism with reversed-phase retention in highly aqueous mobile phase and hydrophilic interaction mechanism in highly organic mobile phase. The retention mechanism was controlled by the composition of the mobile phase and has been described by a three-parameter model. We have used regression parameters to characterize the retention of analyzed compounds and to study individual pathways of dopamine metabolism. Comprehensive optimization of mobile phase composition allowed to find an optimal composition of the mobile phase and stationary phase surface chemistry arrangement to achieve desired separation. Optimized columns provided an isocratic separation of all tested compounds in less than nine min.
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Affiliation(s)
- Martina Komendová
- Department of Chemistry, Faculty of Science, Masaryk University, Brno, Czech Republic
| | | | - Jiří Urban
- Department of Chemistry, Faculty of Science, Masaryk University, Brno, Czech Republic
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12
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Cain CN, Forzano AV, Rutan SC, Collinson MM. Destructive stationary phase gradients for reversed-phase/hydrophilic interaction liquid chromatography. J Chromatogr A 2018; 1570:82-90. [DOI: 10.1016/j.chroma.2018.07.073] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2018] [Revised: 07/24/2018] [Accepted: 07/26/2018] [Indexed: 02/05/2023]
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13
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Jeong LN, Rutan SC. Simulation of elution profiles in liquid chromatography – III. Stationary phase gradients. J Chromatogr A 2018; 1564:128-136. [DOI: 10.1016/j.chroma.2018.06.007] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2018] [Revised: 06/03/2018] [Accepted: 06/04/2018] [Indexed: 02/07/2023]
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14
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Fresco-Cala B, Carrasco-Correa EJ, Cárdenas S, Herrero-Martínez JM. Carbon nanostructures incorporated on methacrylate monoliths for separation of small molecules by nano-liquid chromatography. Microchem J 2018. [DOI: 10.1016/j.microc.2018.03.003] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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15
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Noel Echevarria R, Carrasco-Correa EJ, Keunchkarian S, Reta M, Herrero-Martinez JM. Photografted methacrylate-based monolithic columns coated with cellulose tris(3,5-dimethylphenylcarbamate) for chiral separation in CEC. J Sep Sci 2018; 41:1424-1432. [PMID: 29385319 DOI: 10.1002/jssc.201701234] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2017] [Revised: 01/20/2018] [Accepted: 01/20/2018] [Indexed: 11/10/2022]
Abstract
A chiral capillary monolithic column for enantiomer separation in capillary electrochromatography was prepared by coating cellulose tris(3,5-dimethylphenylcarbamate) on porous glycidyl methacrylate-co-ethylene dimethacrylate monolith in capillary format grafted with chains of [2(methacryloyloxy)ethyl] trimethylammonium chloride. The surface modification of the monolith by the photografting of [2(methacryloyloxy)ethyl] trimethylammonium chloride monomer as well as the coating conditions of cellulose tris(3,5-dimethylphenylcarbamate) onto the grafted monolithic scaffold were optimized to obtain a stable and reproducible chiral stationary phase for capillary electrochromatography. The effect of organic modifier (acetonitrile) in aqueous mobile phase for the enantiomer separation by capillary electrochromatography was also investigated. Several pairs of enantiomers including acidic, neutral, and basic analytes were tested and most of them were partially or completely resolved under aqueous mobile phases. The prepared monolithic chiral stationary phases exhibited a good stability, repeatability, and column-to-column reproducibility, with relative standard deviations below 11% in the studied electrochromatographic parameters.
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Affiliation(s)
- Romina Noel Echevarria
- Laboratorio de Investigación y Desarrollo en Métodos Analíticos (LIDMA), Facultad de Ciencias Exactas, Universidad Nacional de La Plata (UNLP), La Plata, Bs. As., Argentina
| | | | - Sonia Keunchkarian
- Laboratorio de Investigación y Desarrollo en Métodos Analíticos (LIDMA), Facultad de Ciencias Exactas, Universidad Nacional de La Plata (UNLP), La Plata, Bs. As., Argentina
| | - Mario Reta
- Laboratorio de Investigación y Desarrollo en Métodos Analíticos (LIDMA), Facultad de Ciencias Exactas, Universidad Nacional de La Plata (UNLP), La Plata, Bs. As., Argentina
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16
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Collinson MM, Higgins DA. Organosilane Chemical Gradients: Progress, Properties, and Promise. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2017; 33:13719-13732. [PMID: 28849936 DOI: 10.1021/acs.langmuir.7b02259] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Chemical gradients play an important role in nature, driving many different phenomena critical to life, including the transport of chemical species across membranes and the transport, attachment, and assembly of cells. Taking a cue from these natural processes, scientists and engineers are now working to develop synthetic chemical gradients for use in a broad range of applications, such as in high-throughput investigations of surface properties, as means to guide the motions and/or assembly of liquid droplets, vesicles, nanoparticles, and cells and as new media for stationary-phase-gradient chemical separations. Our groups have been working to develop new methods for preparing chemical gradients from organoalkoxysilane and organochlorosilane precursors and to obtain a better understanding of their properties on macroscopic to microscopic length scales. This review highlights our recent work on the development of controlled-rate infusion and infusion-withdrawal dip-coating methods for the preparation of gradients on planar glass and silicon substrates, on thin-layer chromatography plates, and in capillaries and monoliths for liquid chromatography. We also cover the new knowledge gained from the characterization of our gradients using sessile drop and Wilhelmy plate dynamic water contact angle measurements, X-ray photoelectron spectroscopy mapping, and single-molecule tracking and spectroscopy. Our studies reveal important evidence of phase separation and cooperative interactions occurring along multicomponent gradients. Emerging concepts and new directions in the preparation and characterization of organosilane-based chemical gradients are also discussed.
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Affiliation(s)
- Maryanne M Collinson
- Department of Chemistry, Virginia Commonwealth University , 1001 West Main Street, Richmond, Virginia 23284-2006, United States
| | - Daniel A Higgins
- Department of Chemistry, Kansas State University , 1212 Mid-Campus Drive North, Manhattan, Kansas 66506-0401, United States
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17
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Polymer monoliths with silver nanoparticles-cholesterol conjugate as stationary phases for capillary liquid chromatography. J Chromatogr A 2017; 1526:93-103. [DOI: 10.1016/j.chroma.2017.10.039] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2017] [Revised: 10/12/2017] [Accepted: 10/14/2017] [Indexed: 01/03/2023]
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18
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Alvarez-Segura T, Camacho-Molinero C, Torres-Lapasió JR, García-Alvarez-Coque MC. Analysis of amino acids using serially coupled columns. J Sep Sci 2017; 40:2741-2751. [PMID: 28520236 DOI: 10.1002/jssc.201700334] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2017] [Revised: 05/05/2017] [Accepted: 05/08/2017] [Indexed: 11/10/2022]
Abstract
Single conventional columns in reversed-phase liquid chromatography are insufficient for analysing the isoindoles of primary amino acids due to their limited functionality. An interesting possibility for increasing the separation power is the combination of several columns of different nature, where the length is modified by coupling small segments. This approach may require a considerable investment to have multiple lengths for each stationary phase. However, the combination of only two columns of fixed length can be enough to resolve satisfactorily relatively complex mixtures, provided that an optimised gradient program is applied. In this work, a mixture of 19 primary amino acid isoindoles found in proteins was analysed. Four stationary phases were assayed: C18, pentafluorophenyl-C18, C4 and cyano. The mixture of isoindoles was successfully resolved in practical times using a pentafluorophenyl-C18 column coupled to a C4 column, in spite of the extremely poor performance obtained when each column is used isolatedly, independently of the length. The extreme diversity in the polarities of the isoindoles and the need of extrapolating the retention behaviour in certain regions of the solvent content domain makes the modelling of the retention behaviour of the isoindoles particularly difficult. Nevertheless, the predicted optimal separations were very satisfactory.
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19
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Urban J, Hájek T, Svec F. Monolithic stationary phases with a longitudinal gradient of porosity. J Sep Sci 2017; 40:1703-1709. [PMID: 28225173 DOI: 10.1002/jssc.201700048] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2017] [Revised: 02/13/2017] [Accepted: 02/13/2017] [Indexed: 11/12/2022]
Abstract
The duration of the hypercrosslinking reaction has been used to control the extent of small pores formation in polymer-based monolithic stationary phases. Segments of five columns hypercrosslinked for 30-360 min were coupled via zero-volume unions to prepare columns with segmented porosity gradients. The steepness of the porosity gradient affected column efficiency, mass transfer resistance, and separation of both small-molecule alkylbenzenes and high-molar-mass polystyrene standards. In addition, the segmented column with the steepest porosity gradient was prepared as a single column with a continuous porosity gradient. The steepness of porosity gradient in this type column was tuned. Compared to a completely hypercrosslinked column, the column with the shallower gradient produced comparable size-exclusion separation of polystyrene standards but allowed higher column permeability. The completely hypercrosslinked column and the column with porosity gradient were successfully coupled in online two-dimensional liquid chromatography of polymers.
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Affiliation(s)
- Jiří Urban
- Department of Analytical Chemistry, Faculty of Chemical Technology, University of Pardubice, Pardubice, Czech Republic
| | - Tomáš Hájek
- Department of Analytical Chemistry, Faculty of Chemical Technology, University of Pardubice, Pardubice, Czech Republic
| | - Frantisek Svec
- The Molecular Foundry, E.O. Lawrence Berkeley National Laboratory, Berkeley, CA, USA
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20
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Li J, Kwiatkowska B, Lu H, Voglstätter M, Ueda E, Grunze M, Sleeman J, Levkin PA, Nazarenko I. Collaborative Action of Surface Chemistry and Topography in the Regulation of Mesenchymal and Epithelial Markers and the Shape of Cancer Cells. ACS APPLIED MATERIALS & INTERFACES 2016; 8:28554-28565. [PMID: 27731629 DOI: 10.1021/acsami.6b11338] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/16/2023]
Abstract
Malignant transformation is associated with enhancement of cell plasticity, which allows cancer cells to survive under different conditions by adapting to their microenvironment during growth and metastatic spread. Much effort has been devoted to understanding the molecular mechanisms of these processes. Although the importance of the extracellular matrix and of surface properties in these mechanisms is evident, the direct impact of distinct physical and chemical surfaces characteristics on cell fate remains unclear. Here, we have addressed this question using HT1080 fibrosarcoma cells as a model. To examine the relationship between surface topography, chemistry, and cell behavior, hydrophobic poly(butyl methacrylate-co-ethylene dimethacrylate) (BMA-EDMA) and hydrophilic poly(2-hydroxyethyl methacrylate-co-ethylene dimethacrylate) (HEMA-EDMA) surfaces with three different topographies (microporous, nanoporous, and nonporous) were generated. These surfaces were then modified by photoinitiated grafting of three different methacrylate monomers to create surface chemistry gradients of either negatively (AMPS) or positively (META) charged or zwitterionic (MDSA) functionalities. Our results show that AMPS promotes cell spreading, but that META abolishes cell growth. META and MDSA grafted on microporous BMA-EDMA produced superhydrophilic surfaces with high globularity and elasticity, which modified the cell phenotype by inhibiting cell spreading, followed by loss of mesenchymal characteristics and a reduction in protein levels of the mesenchymal markers N-cadherin, beta-catenin, p120 catenin, and also of the adaptor proteins vinculin and paxillin that are associated with adhesion and cancer cell invasion. The effect was strengthened along the gradient, suggesting that the density of the functional groups plays a role in this process. On the nanoporous surface, only MDSA grafting resulted in a significant increase in cell number, a reduction in N-cadherin expression, increased beta-catenin and p120 catenin levels, as well as the appearance of the epithelial marker E-cadherin. This indicates that the cancer cells have a high plasticity that is triggered by the collaborative effect of physical and chemical surface properties.
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Affiliation(s)
- Junsheng Li
- Institute of Toxicology and Genetics, Karlsruhe Institute of Technology , 76021 Karlsruhe, Germany
- Applied Physical Chemistry, University of Heidelberg , 69120 Heidelberg, Germany
- School of Chemistry, Chemical Engineering and Life Sciences, Wuhan University of Technology , Wuhan 430070, China
| | - Barbara Kwiatkowska
- Institute of Toxicology and Genetics, Karlsruhe Institute of Technology , 76021 Karlsruhe, Germany
| | - Hao Lu
- Applied Physical Chemistry, University of Heidelberg , 69120 Heidelberg, Germany
| | - Maren Voglstätter
- Institute of Environmental Health Sciences and Hospital Infection Control, Medical Center, University of Freiburg , 79106 Freiburg, Germany
| | - Erika Ueda
- Institute of Toxicology and Genetics, Karlsruhe Institute of Technology , 76021 Karlsruhe, Germany
| | - Michael Grunze
- Applied Physical Chemistry, University of Heidelberg , 69120 Heidelberg, Germany
- Institute of Functional Interfaces (IFG), Karlsruhe Institute of Technology (KIT) , Germany
| | - Jonathan Sleeman
- Institute of Toxicology and Genetics, Karlsruhe Institute of Technology , 76021 Karlsruhe, Germany
- Centre for Biomedicine and Medical Technology Mannheim (CBTM), University Medicine Mannheim and University of Heidelberg , D-68167 Mannheim, Germany
| | - Pavel A Levkin
- Institute of Toxicology and Genetics, Karlsruhe Institute of Technology , 76021 Karlsruhe, Germany
- Applied Physical Chemistry, University of Heidelberg , 69120 Heidelberg, Germany
| | - Irina Nazarenko
- Institute of Toxicology and Genetics, Karlsruhe Institute of Technology , 76021 Karlsruhe, Germany
- Institute of Environmental Health Sciences and Hospital Infection Control, Medical Center, University of Freiburg , 79106 Freiburg, Germany
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21
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Dewoolkar VC, Jeong LN, Cook DW, Ashraf KM, Rutan SC, Collinson MM. Amine Gradient Stationary Phases on In-House Built Monolithic Columns for Liquid Chromatography. Anal Chem 2016; 88:5941-9. [DOI: 10.1021/acs.analchem.6b00895] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Affiliation(s)
- Veeren C. Dewoolkar
- Department of Chemistry, Virginia Commonwealth University, Richmond, Virginia 23284-2006, United States
| | - Lena N. Jeong
- Department of Chemistry, Virginia Commonwealth University, Richmond, Virginia 23284-2006, United States
| | - Daniel W. Cook
- Department of Chemistry, Virginia Commonwealth University, Richmond, Virginia 23284-2006, United States
| | - Kayesh M. Ashraf
- Department of Chemistry, Virginia Commonwealth University, Richmond, Virginia 23284-2006, United States
| | - Sarah C. Rutan
- Department of Chemistry, Virginia Commonwealth University, Richmond, Virginia 23284-2006, United States
| | - Maryanne M. Collinson
- Department of Chemistry, Virginia Commonwealth University, Richmond, Virginia 23284-2006, United States
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22
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Currivan S, Connolly D, Paull B. Stepped gradients on polymeric monolithic columns by photoinitiated grafting. J Sep Sci 2015; 38:3795-802. [DOI: 10.1002/jssc.201500776] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2015] [Revised: 08/13/2015] [Accepted: 08/14/2015] [Indexed: 11/11/2022]
Affiliation(s)
- Sinéad Currivan
- Australian Centre for Research on Separation Science, School of Physical Sciences; University of Tasmania; Sandy Bay, Hobart Tasmania Australia
| | - Damian Connolly
- Pharmaceutical and Molecular Biotechnology Research Centre, Department of Science; Waterford Institute of Technology; Waterford Ireland
| | - Brett Paull
- Australian Centre for Research on Separation Science, School of Physical Sciences; University of Tasmania; Sandy Bay, Hobart Tasmania Australia
- ARC Centre of Excellence for Electromaterials Science, School of Physical Sciences; University of Tasmania; Sandy Bay, Hobart Tasmania Australia
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23
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Continuous affinity-gradient nano-stationary phase served as a column for reversed-phase electrochromatography and matrix carrier in time-of-flight mass spectrometry for protein analysis. Anal Chim Acta 2015; 889:166-71. [DOI: 10.1016/j.aca.2015.07.034] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2014] [Revised: 06/11/2015] [Accepted: 07/08/2015] [Indexed: 11/22/2022]
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24
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Currivan S, Macak JM, Jandera P. Polymethacrylate monolithic columns for hydrophilic interaction liquid chromatography prepared using a secondary surface polymerization. J Chromatogr A 2015; 1402:82-93. [DOI: 10.1016/j.chroma.2015.05.016] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2015] [Revised: 05/05/2015] [Accepted: 05/07/2015] [Indexed: 10/23/2022]
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25
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Vonk RJ, Wouters S, Barcaru A, Vivó-Truyols G, Eeltink S, de Koning LJ, Schoenmakers PJ. Post-polymerization photografting on methacrylate-based monoliths for separation of intact proteins and protein digests with comprehensive two-dimensional liquid chromatography hyphenated with high-resolution mass spectrometry. Anal Bioanal Chem 2015; 407:3817-29. [PMID: 25801383 PMCID: PMC4412387 DOI: 10.1007/s00216-015-8615-4] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2015] [Revised: 02/27/2015] [Accepted: 03/03/2015] [Indexed: 12/03/2022]
Abstract
Post-polymerization photografting is a versatile tool to alter the surface chemistry of organic-based monoliths so as to obtain desired stationary phase properties. In this study, 2-acrylamido-2-methyl-1-propanesulfonic acid was grafted to a hydrophobic poly(butyl methacrylate-co-ethylene glycol dimethacrylate) monolith to create a strong cation exchange stationary phase. Both single-step and two-step photografting were addressed, and the effects of grafting conditions were assessed. An experimental design has been applied in an attempt to optimize three of the key parameters of the two-step photografting chemistry, i.e. the grafting time of the initiator, the monomer concentration and the monomer irradiation time. The photografted columns were implemented in a comprehensive two-dimensional column liquid chromatography (tLC × tLC) workflow and applied for the separation of intact proteins and peptides. A baseline separation of 11 intact proteins was obtained within 20 min by implementing a gradient across a limited RP composition window in the second dimension. tLC × tLC with UV detection was used for the separation of cytochrome c digest, bovine serum insulin digest and a digest of a complex protein mixture. A semi-quantitative estimation of the occupation of separation space, the orthogonality, of the tLC × tLC system yielded 75 %. The tLC × tLC setup was hyphenated to a high-resolution Fourier transform ion cyclotron resonance mass spectrometer instrument to identify the bovine serum insulin tryptic peptides and to demonstrate the compatibility with MS analysis.
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Affiliation(s)
- Rudy J Vonk
- Analytical-Chemistry Group, van't Hoff Institute for Molecular Sciences, University of Amsterdam, Science Park 904, 1098 XH, Amsterdam, The Netherlands,
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26
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Kannan B, Higgins DA, Collinson MM. Chelation gradients for investigation of metal ion binding at silica surfaces. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2014; 30:10019-10027. [PMID: 25127401 DOI: 10.1021/la502088k] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
Centimeter-long surface gradients in bi- and tridentate chelating agents have been formed via controlled rate infusion, and the coordination of Cu(2+) and Zn(2+) to these surfaces has been examined as a function of distance by X-ray photoelectron spectroscopy (XPS). 3-(Trimethoxysilylpropyl)ethylenediamine and 3-(trimethoxysilylpropyl)diethylenetriamine were used as precursor silanes to form the chelation gradients. When the gradients were exposed to a metal ion solution, a series of coordination complexes formed along the length of the substrate. For both chelating agents at the three different concentrations studied, the amine content gradually increased from top to bottom as expected for a surface chemical gradient. While the Cu 2p peak area had nearly the same profile as nitrogen, the Zn 2p peak area did not and exhibited a plateau along much of the gradient. The normalized nitrogen-to-metal peak area ratio (N/M) was found to be highly dependent on the type of ligand, its surface concentration, and the type of metal ion. For Cu(2+), the N/M ratio ranged from 8 to 11 on the diamine gradient and was ∼4 on the triamine gradient, while for Zn(2+), the N/M ratio was 4-8 on diamine and 5-7 on triamine gradients. The extent of protonation of amine groups was higher for the diamine gradients, which could lead to an increased N/M ratio. Both 1:1 and 1:2 ligand/metal complexes along with dinuclear complexes are proposed to form, with their relative amounts dependent on the ligand, ligand density, and metal ion. Collectively, the methods and results described herein represent a new approach to study metal ion binding and coordination on surfaces, which is especially important to the extraction, preconcentration, and separation of metal ions.
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Affiliation(s)
- Balamurali Kannan
- Department of Chemistry, Virginia Commonwealth University , Richmond, Virginia 23284-2006, United States
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27
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28
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Kannan B, Nokura K, Alvarez JC, Higgins DA, Collinson MM. Fabrication of surface charge gradients in open-tubular capillaries and their characterization by spatially resolved pulsed streaming potential measurements. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2013; 29:15260-15265. [PMID: 24274139 DOI: 10.1021/la402934m] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
Surface charge gradients have been formed on the inside surface of 75 μm i.d. silica capillaries via controlled rate infusion using 3-aminopropyltriethoxysilane as the reactive precursor. These 400 mm length gradients have been characterized using spatially resolved streaming potential measurements, from which the zeta potential as a function of distance was determined. The gradient capillaries exhibited a gradual variation in zeta potential from top to bottom, whereas uniformly modified and as-received capillaries were relatively homogeneous along their length. For a gradient prepared with a relatively high concentration of aminosilane, the zeta potential changed over 60 mV from one end of the capillary to the other, yielding a variation in the magnitude of the apparent surface charge of ~7 fold. By changing the concentration of the aminoalkoxysilane and/or the rate of infusion, both the value of the zeta potential (and hence surface charge) and its spatial profile (i.e., rate of change with distance) could be manipulated.
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Affiliation(s)
- Balamurali Kannan
- Department of Chemistry, Virginia Commonwealth University , Richmond, Virginia 23284-2006, United States
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29
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Currivan S, Connolly D, Paull B. Production of polymer monolithic capillary columns with integrated gold nano-particle modified segments for on-capillary extraction. Microchem J 2013. [DOI: 10.1016/j.microc.2012.08.007] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
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30
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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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31
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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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32
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Kannan B, Higgins DA, Collinson MM. Aminoalkoxysilane reactivity in surface amine gradients prepared by controlled-rate infusion. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2012; 28:16091-16098. [PMID: 23130663 DOI: 10.1021/la303580c] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
The reactivity of a series of substituted aminoalkoxysilanes for surface amine gradient formation has been studied using a newly developed time-based exposure method termed controlled-rate infusion (CRI). The aminoalkoxysilanes used include those that contain primary, secondary, and tertiary monoamines as well as more than one amine group (diamine and triamine). X-ray photoelectron spectroscopy (XPS) was used to confirm the presence of a gradient in each case and to acquire detailed information on gradient composition from which kinetic data were obtained. The total area under the N 1s XPS spectra allows for the extent of amine modification to be quantitatively assessed along each gradient. The N 1s peaks actually appear as doublets, providing additional data on the level of protonation and, hence, amine basicity on the dry surface. The degree of protonation showed an interesting trend toward smaller values running from top to bottom along gradients incorporating the most basic amines. The gradient profiles, including initial steepness and extent of saturation, were shown to be highly dependent on the aminoalkoxysilane precursor employed. The highest levels of modification were achieved for the diamine and primary monoamine precursors while the more hindered amines produced lower levels of surface modification and took longer for saturation to be achieved. By fitting the gradient data to a simple first-order kinetic model, rate constants for the condensation reaction between each aminosilane and accessible surface silanol groups were obtained. The rate constants follow the trend: triamine ~ diamine > monoamine and primary > secondary > tertiary, indicating kinetic factors also play an important role in controlling surface modification. The presence of more than one amine group on the silane is concluded to enhance the rate of condensation to the surface silanol groups, while the more hindered secondary and tertiary amines slow condensation. Collectively, the results provide valuable new data on how the number of amine groups, degree of substitution, and steric hindrance influence silane reactivity with silica surfaces, amine surface coverage, and basicity along the gradient profile.
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Affiliation(s)
- Balamurali Kannan
- Department of Chemistry, Virginia Commonwealth University, Richmond, Virginia 23284-2006, United States
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33
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Lv Y, Alejandro FM, Fréchet JMJ, Svec F. Preparation of porous polymer monoliths featuring enhanced surface coverage with gold nanoparticles. J Chromatogr A 2012; 1261:121-8. [PMID: 22542442 PMCID: PMC3424317 DOI: 10.1016/j.chroma.2012.04.007] [Citation(s) in RCA: 109] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2012] [Revised: 04/02/2012] [Accepted: 04/03/2012] [Indexed: 11/20/2022]
Abstract
A new approach to the preparation of porous polymer monoliths with enhanced coverage of pore surface with gold nanoparticles has been developed. First, a generic poly(glycidyl methacrylate-co-ethylene dimethacrylate) monolith was reacted with cystamine followed by the cleavage of its disulfide bonds with tris(2-carboxylethyl)phosphine, which liberated the desired thiol groups. Dispersions of gold nanoparticles with sizes varying from 5 to 40 nm were then pumped through the functionalized monoliths. The materials were then analyzed using both energy dispersive X-ray spectroscopy and thermogravimetric analysis. We found that the quantity of attached gold was dependent on the size of nanoparticles, with the maximum attachment of more than 60 wt% being achieved with 40 nm nanoparticles. Scanning electron micrographs of the cross sections of all the monoliths revealed the formation of a non-aggregated, homogenous monolayer of nanoparticles. The surface of the bound gold was functionalized with 1-octanethiol and 1-octadecanethiol, and these monolithic columns were used successfully for the separations of proteins in reversed phase mode. The best separations were obtained using monoliths modified with 15, 20, and 30 nm nanoparticles since these sizes produced the most dense coverage of pore surface with gold.
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Affiliation(s)
- Yongqin Lv
- Department of Chemistry, University of California, Berkeley, CA 94720, USA
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34
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Currivan S, Connolly D, Paull B. Production of novel polymer monolithic columns, with stationary phase gradients, using cyclic olefin co-polymer (COC) optical filters. Analyst 2012; 137:2559-66. [PMID: 22534833 DOI: 10.1039/c2an35316d] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Polymer monolithic columns with controlled surface ligand density, providing stationary phase gradients within monolithic capillary columns, have been developed using photo-grafting through optical filters. Utilising commercially available cyclic olefin co-polymer (COC) films, the production of an optical filter capable of attenuating UV irradiation, in a tailored manner, was investigated. This novel optical filter was successfully applied to the surface modification of poly(BuMA-co-EDMA) monolithic columns in a multi-step grafting procedure. Fabricated columns were subjected to scanning capacitively coupled contactless conductivity (sC(4)D), to determine the distribution of the grafted functional groups, axially along the column. Further modification to produce a chelating stationary phase gradient of iminodiacetic acid (IDA) was demonstrated. To demonstrate the distribution of the IDA sites, a metal cation (Cu(2+)) was complexed to the IDA forming a chelate. Upon the formation of a complex of IDA with Cu(2+), an overall drop in conductive response was observed. The COC optical filter was also used in the fabrication of a grafted gradient of strong cation exchanger (SCX), sulphopropyl methacrylate (SPM) upon a polymer monolith, demonstrating the broader applicability of such a filter.
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Affiliation(s)
- Sinéad Currivan
- Irish Separation Science Cluster, National Centre for Sensor Research, Dublin City University, Glasnevin, Ireland
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35
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Kannan B, Marin MA, Shrestha K, Higgins DA, Collinson MM. Continuous stationary phase gradients for planar chromatographic media. J Chromatogr A 2011; 1218:9406-13. [DOI: 10.1016/j.chroma.2011.10.075] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2011] [Revised: 10/20/2011] [Accepted: 10/21/2011] [Indexed: 10/15/2022]
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36
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Urbanova I, Svec F. Monolithic polymer layer with gradient of hydrophobicity for separation of peptides using two-dimensional thin layer chromatography and MALDI-TOF-MS detection. J Sep Sci 2011; 34:2345-51. [DOI: 10.1002/jssc.201100202] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2011] [Revised: 05/08/2011] [Accepted: 05/08/2011] [Indexed: 11/11/2022]
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37
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Nordborg A, Hilder EF, Haddad PR. Monolithic phases for ion chromatography. ANNUAL REVIEW OF ANALYTICAL CHEMISTRY (PALO ALTO, CALIF.) 2011; 4:197-226. [PMID: 21689046 DOI: 10.1146/annurev-anchem-061010-113929] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
Monolithic media are continuing to increase in popularity in chromatographic applications, and the ongoing use of commercially available materials in ion chromatography (IC) has made monoliths a viable alternative to packed-bed columns for routine use. We discuss different strategies for the synthesis of polymeric and silica monoliths with ion-exchange functionality, such as direct incorporation of ion-exchange functionality during monolith preparation and different postpolymerization alterations such as grafting and coating. The formulations and strategies presented are focused on materials intended for use in IC. We also discuss strategies for materials characterization, with emphasis on nondestructive techniques for the characterization of monolith surface functionality, especially those with applicability to in situ analysis. Finally, we describe selected IC applications of polymeric and silica monoliths published from 2008 to 2010.
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Affiliation(s)
- Anna Nordborg
- Australian Center for Research on Separation Science, School of Chemistry, University of Tasmania, Hobart, Tasmania 7001, Australia.
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38
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Zajickova Z, Luna J, Svec F. SURFACE MODIFICATION OF SILICA-BASED MONOLITH WITH POLY(PENTAFLUOROPROPYL METHACRYLATE) USING SINGLE STEP PHOTOGRAFTING. J LIQ CHROMATOGR R T 2010. [DOI: 10.1080/10826076.2010.519244] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Affiliation(s)
- Zuzana Zajickova
- a Department of Physical Sciences , Barry University , Miami Shores, Florida, USA
| | - Joao Luna
- a Department of Physical Sciences , Barry University , Miami Shores, Florida, USA
| | - Frantisek Svec
- b The Molecular Foundry, Lawrence Berkeley National Laboratory , Berkeley, California, USA
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39
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Zheng MM, Wang ST, Hu WK, Feng YQ. In-tube solid-phase microextraction based on hybrid silica monolith coupled to liquid chromatography–mass spectrometry for automated analysis of ten antidepressants in human urine and plasma. J Chromatogr A 2010; 1217:7493-501. [DOI: 10.1016/j.chroma.2010.10.002] [Citation(s) in RCA: 104] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2010] [Revised: 09/30/2010] [Accepted: 10/01/2010] [Indexed: 11/16/2022]
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40
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Non-invasive characterization of stationary phases in capillary flow systems using scanning capacitively coupled contactless conductivity detection (sC4D). Trends Analyt Chem 2010. [DOI: 10.1016/j.trac.2010.04.007] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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41
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Han Y, Levkin P, Abarientos I, Liu H, Svec F, Fréchet JM. Monolithic superhydrophobic polymer layer with photopatterned virtual channel for the separation of peptides using two-dimensional thin layer chromatography-desorption electrospray ionization mass spectrometry. Anal Chem 2010; 82:2520-8. [PMID: 20151661 PMCID: PMC2921584 DOI: 10.1021/ac100010h] [Citation(s) in RCA: 63] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Superhydrophobic monolithic porous polymer layers with a photopatterned hydrophilic channel have been prepared. These layers were used for two-dimensional thin layer chromatography of peptides. The 50 microm thin poly(butyl methacrylate-co-ethylene dimethacrylate) layers supported onto 4.0 x 3.3 cm glass plates were prepared using UV-initiated polymerization in a simple glass mold. Photografting of a mixture of 2-acrylamido-2-methyl-1-propanesulfonic acid and 2-hydroxyethyl methacrylate carried out through a mask afforded a 600 microm wide virtual channel along one side of the layer. This channel, which contains ionizable functionalities, enabled the first dimension separation in ion exchange mode. The aqueous mobile phase migrates only through the channel due to the large difference in surface tension at the interface of the hydrophilic channel and the superhydrophobic monolith. The unmodified part of the layer featuring hydrophobic chemistry was then used for the reversed phase separation in the orthogonal second dimension. Practical application of our technique was demonstrated with a rapid 2D separation of a mixture of model peptides differing in hydrophobicity and isoelectric point using a combination of ion-exchange and reversed phase modes. In the former mode, the peptides migrated 11 mm in less than 1 min. Detection of fluorescently labeled peptides was achieved through UV light visualization. Separation of the native peptides was monitored directly using a desorption electrospray ionization (DESI) source coupled to a mass spectrometer. Unidirectional surface scanning with the DESI source was found suitable to determine both the location of each separated peptide and its molecular mass.
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Affiliation(s)
| | | | | | | | | | - Jean M.J. Fréchet
- To whom correspondence should be addressed. Phone: 510 643 3077. Fax: 510 643 3077.
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42
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Currivan S, Connolly D, Gillespie E, Paull B. Fabrication and characterisation of capillary polymeric monoliths incorporating continuous stationary phase gradients. J Sep Sci 2010; 33:484-92. [DOI: 10.1002/jssc.200900720] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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43
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Hybrid organic–inorganic silica monolith with hydrophobic/strong cation-exchange functional groups as a sorbent for micro-solid phase extraction. J Chromatogr A 2009; 1216:7739-46. [DOI: 10.1016/j.chroma.2009.08.085] [Citation(s) in RCA: 59] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2009] [Revised: 08/25/2009] [Accepted: 08/31/2009] [Indexed: 11/20/2022]
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44
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Krenkova J, Gargano A, Lacher NA, Schneiderheinze JM, Svec F. High binding capacity surface grafted monolithic columns for cation exchange chromatography of proteins and peptides. J Chromatogr A 2009; 1216:6824-30. [DOI: 10.1016/j.chroma.2009.08.031] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2009] [Revised: 08/06/2009] [Accepted: 08/12/2009] [Indexed: 10/20/2022]
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45
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Bernabé-Zafón V, Cantó-Mirapeix A, Simó-Alfonso EF, Ramis-Ramos G, Herrero-Martínez JM. Comparison of thermal- and photo-polymerization of lauryl methacrylate monolithic columns for CEC. Electrophoresis 2009; 30:1929-36. [PMID: 19517443 DOI: 10.1002/elps.200800553] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Lauryl methacrylate-based (LMA) monolithic columns for CEC, prepared using either thermal initiation or by UV-irradiation in the presence of AIBN have been compared. Thermal polymerization was carried out at 70 degrees C for 20 h. For UV initiation, the effects of the time exposure to UV light and irradiation energy were investigated. For each initiation process, the influence of composition of porogenic solvent (1,4-butanediol/1-propanol ratio) on the physical and electrochromatographic properties of the resulting monoliths was also evaluated. Photochemically lauryl methacrylate stationary phases initiated showed higher permeabilities and better efficiencies than those prepared by thermal initiation. After optimization of polymerization mixture, photopolymerized columns provided a permeability of 4.25 x 10(-13) m(2) and a minimum plate height of 13.4 microm for a mixture of polycyclic aromatic hydrocarbons. Similar column-to-column and batch-to-batch reproducibilities, with RSD values below 11.6 and 11.0 % for the thermal- and UV-initiated columns, respectively, were obtained.
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Affiliation(s)
- Virginia Bernabé-Zafón
- Department of Analytical Chemistry, Faculty of Chemistry, University of Valencia, Valencia, Spain
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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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Polymeric strong cation-exchange monolithic column for capillary liquid chromatography of peptides and proteins. J Sep Sci 2009; 32:2565-73. [DOI: 10.1002/jssc.200900255] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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Connolly D, Paull B. High-performance separation of small inorganic anions on a methacrylate-based polymer monolith grafted with [2(methacryloyloxy)ethyl] trimethylammonium chloride. J Sep Sci 2009; 32:2653-8. [DOI: 10.1002/jssc.200900229] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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Gillespie E, Connolly D, Nesterenko PN, Paull B. On-column titration and investigation of metal complex formation for aminopolycarboxylate functionalised monoliths using scanning contactless conductivity detection. J Sep Sci 2009; 32:2659-67. [DOI: 10.1002/jssc.200900232] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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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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