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Tallarek U, Trebel N, Frerichs D, Steinhoff A, Höltzel A. Organic-solvent ditch overlap in reversed-phase liquid chromatography: A molecular dynamics simulation study in cylindrical 6-12 nm-diameter pores. J Chromatogr A 2024; 1726:464960. [PMID: 38718695 DOI: 10.1016/j.chroma.2024.464960] [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: 02/21/2024] [Revised: 04/28/2024] [Accepted: 04/30/2024] [Indexed: 05/23/2024]
Abstract
Mass transport through the mesopore space of a reversed-phase liquid chromatography (RPLC) column depends on the properties of the chromatographic interface, particularly on the extent of the organic-solvent ditch that favors the analyte surface diffusivity. Through molecular dynamics simulations in cylindrical RPLC mesopore models with pore diameters between 6 and 12 nm we systematically trace the evolution of organic-solvent ditch overlap due to spatial confinement in the mesopore space of RPLC columns for small-molecule separations. Each pore model of a silica-based, endcapped, C18-stationary phase is equilibrated with two mobile phases of comparable elution strength, namely 70/30 (v/v) water/acetonitrile and 60/40 (v/v) water/methanol, to consider the influence of the mobile-phase composition on the onset of organic-solvent ditch overlap. The simulations show that, as the pore diameter decreases from 9 to 6 nm, the bonded-phase density extends and compacts towards the pore center, which leads to increased accumulation of organic-solvent excess and thus enhanced organic-solvent diffusivity in the ditch. Because the acetonitrile ditch is more pronounced than the methanol ditch, acetonitrile ditch overlap sets in at less severe spatial confinement than methanol ditch overlap. The pore-averaged methanol and acetonitrile diffusivities are considerably raised by ditch overlap in the 6 nm-diameter pore, but also benefit from the ditch (without overlap) in the 7 to 12 nm-diameter pores, whereby local and pore-averaged effects are generally larger for acetonitrile than methanol.
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Affiliation(s)
- Ulrich Tallarek
- Department of Chemistry, Philipps-Universität Marburg, Hans-Meerwein-Strasse 4, Marburg 35032, Germany.
| | - Nicole Trebel
- Department of Chemistry, Philipps-Universität Marburg, Hans-Meerwein-Strasse 4, Marburg 35032, Germany
| | - Daniel Frerichs
- Department of Chemistry, Philipps-Universität Marburg, Hans-Meerwein-Strasse 4, Marburg 35032, Germany
| | - Andreas Steinhoff
- Department of Chemistry, Philipps-Universität Marburg, Hans-Meerwein-Strasse 4, Marburg 35032, Germany
| | - Alexandra Höltzel
- Department of Chemistry, Philipps-Universität Marburg, Hans-Meerwein-Strasse 4, Marburg 35032, Germany
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2
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Steinhoff A, Höltzel A, Trebel N, Tallarek U. Mobile-Phase Contributions to Organic-Solvent Excess Adsorption and Surface Diffusion in Reversed-Phase Liquid Chromatography. J Phys Chem B 2022; 126:10554-10568. [PMID: 36469753 DOI: 10.1021/acs.jpcb.2c06871] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Fast transport of retained analytes in reversed-phase liquid chromatography occurs through surface diffusion in the organic-solvent (OS)-enriched interfacial "ditch" region between the hydrophobic stationary phase and the water (W)-OS mobile phase. Through molecular dynamics simulations that recover the OS excess adsorption isotherms of a typical C18-stationary phase for methanol and acetonitrile, we explore the relation between OS properties, OS excess adsorption, and surface diffusion. The emerging molecular-level picture attributes the mobile-phase contribution to surface diffusion to the hydrogen-bond capability and the eluting power of the OS. The higher affinity of methanol for the formation of W-OS hydrogen bonds at the soft, hydrophobic surface presented by the bonded-phase (C18) chains reduces the OS excess and the related viscosity drop in the ditch. The lower eluting power of methanol, however, translates to increased bonded-phase contacts for analytes, which can increase their mobility gain from surface diffusion above the gain observed with acetonitrile.
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Affiliation(s)
- Andreas Steinhoff
- Department of Chemistry, Philipps-Universität Marburg, Hans-Meerwein-Strasse 4, 35032Marburg, Germany
| | - Alexandra Höltzel
- Department of Chemistry, Philipps-Universität Marburg, Hans-Meerwein-Strasse 4, 35032Marburg, Germany
| | - Nicole Trebel
- Department of Chemistry, Philipps-Universität Marburg, Hans-Meerwein-Strasse 4, 35032Marburg, Germany
| | - Ulrich Tallarek
- Department of Chemistry, Philipps-Universität Marburg, Hans-Meerwein-Strasse 4, 35032Marburg, Germany
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3
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Pahari S, Dorneles de Mello M, Shah MS, Josephson TR, Ren L, Nguyen HGT, Van Zee RD, Tsapatsis M, Siepmann JI. Ethanol and Water Adsorption in Conventional and Hierarchical All-Silica MFI Zeolites. ACS PHYSICAL CHEMISTRY AU 2022; 2:79-88. [PMID: 36855513 PMCID: PMC9718309 DOI: 10.1021/acsphyschemau.1c00026] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 06/18/2023]
Abstract
Hierarchical zeolites containing both micro- (<2 nm) and mesopores (2-50 nm) have gained increasing attention in recent years because they combine the intrinsic properties of conventional zeolites with enhanced mass transport rates due to the presence of mesopores. The structure of the hierarchical self-pillared pentasil (SPP) zeolite is of interest because all-silica SPP consists of orthogonally intergrown single-unit-cell MFI nanosheets and contains hydrophilic surface silanol groups on the mesopore surface while its micropores are nominally hydrophobic. Therefore, the distribution of adsorbed polar molecules, like water and ethanol, in the meso- and micropores is of fundamental interest. Here, molecular simulation and experiment are used to investigate the adsorption of water and ethanol on SPP. Vapor-phase single-component adsorption shows that water occupies preferentially the mesopore corner and surface regions of the SPP material at lower pressures (P/P 0 < 0.5) while loading in the mesopore interior dominates adsorption at higher pressures. In contrast, ethanol does not exhibit a marked preference for micro- or mesopores at low pressures. Liquid-phase adsorption from binary water-ethanol mixtures demonstrates a 2 orders of magnitude lower ethanol/water selectivity for the SPP material compared to bulk MFI. For very dilute aqueous solutions of ethanol, the ethanol molecules are mostly adsorbed inside the SPP micropore region due to stronger dispersion interactions and the competition from water for the surface silanols. At high ethanol concentrations (C EtOH > 700 g L-1), the SPP material becomes selective for water over ethanol.
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Affiliation(s)
- Swagata Pahari
- Department
of Chemistry and Chemical Theory Center, University of Minnesota, 207 Pleasant Street SE, Minneapolis, Minnesota 55455-0431, United States
| | - Matheus Dorneles de Mello
- Department
of Chemical Engineering and Materials Science, University of Minnesota, 421 Washington Avenue SE, Minneapolis, Minnesota 55455-0132, United States
| | - Mansi S. Shah
- Department
of Chemistry and Chemical Theory Center, University of Minnesota, 207 Pleasant Street SE, Minneapolis, Minnesota 55455-0431, United States
- Department
of Chemical Engineering and Materials Science, University of Minnesota, 421 Washington Avenue SE, Minneapolis, Minnesota 55455-0132, United States
| | - Tyler R. Josephson
- Department
of Chemistry and Chemical Theory Center, University of Minnesota, 207 Pleasant Street SE, Minneapolis, Minnesota 55455-0431, United States
| | - Limin Ren
- Department
of Chemical Engineering and Materials Science, University of Minnesota, 421 Washington Avenue SE, Minneapolis, Minnesota 55455-0132, United States
| | - Huong Giang T. Nguyen
- Facility
for Adsorbent Characterization and Testing, National Institute of Standards and Technology, Gaithersburg, Maryland 20899, United States
| | - Roger D. Van Zee
- Facility
for Adsorbent Characterization and Testing, National Institute of Standards and Technology, Gaithersburg, Maryland 20899, United States
| | - Michael Tsapatsis
- Department
of Chemical Biomolecular Engineering and Institute for NanoBiotechnology, Johns Hopkins University, 3400 North Charles Street, Baltimore, Maryland 21218, United States
- Applied
Physics Laboratory, Johns Hopkins University, 11100 Johns Hopkins Road, Laurel, Maryland 20723-6099, United States
| | - J. Ilja Siepmann
- Department
of Chemistry and Chemical Theory Center, University of Minnesota, 207 Pleasant Street SE, Minneapolis, Minnesota 55455-0431, United States
- Department
of Chemical Engineering and Materials Science, University of Minnesota, 421 Washington Avenue SE, Minneapolis, Minnesota 55455-0132, United States
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4
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Trebel N, Höltzel A, Lutz JK, Tallarek U. Consequences of Cylindrical Pore Geometry for Interfacial Phenomena in Reversed-Phase Liquid Chromatography. J Phys Chem B 2021; 125:11320-11336. [PMID: 34610741 DOI: 10.1021/acs.jpcb.1c06732] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The interfacial phenomena behind analyte separation in a reversed-phase liquid chromatography column take place nearly exclusively inside the silica mesopores. Their cylindrical geometry can be expected to shape the properties of the chromatographic interface with consequences for the analyte density distribution and diffusivity. To investigate this topic through molecular dynamics simulations, we introduce a cylindrical pore inside a slit pore configuration, where the inner curved and outer planar silica surface bear the same bonded phase. The present model replicates an average-sized (9 nm) mesopore in an endcapped C18 column equilibrated with a mobile phase of 70/30 (v/v) water/acetonitrile. Simulations performed for ethylbenzene and acetophenone show that the surface curvature shifts the bonded phase and analyte density toward the pore center, decreases the solvent density in the bonded-phase region, increases the acetonitrile excess in the interfacial region, and considerably enhances the surface diffusivity of both analytes. Overall, the cylindrical pore provides a more hydrophobic environment than the slit pore. Ethylbenzene density is decidedly increased in the cylindrical pore, whereas acetophenone density is nearly equally distributed between the cylindrical and slit pore. The cylindrical pore geometry thus sharpens the discrimination between the apolar and moderately polar analytes while enhancing the mass transport of both.
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Affiliation(s)
- Nicole Trebel
- Department of Chemistry, Philipps-Universität Marburg, Hans-Meerwein-Strasse 4, 35032 Marburg, Germany
| | - Alexandra Höltzel
- Department of Chemistry, Philipps-Universität Marburg, Hans-Meerwein-Strasse 4, 35032 Marburg, Germany
| | - Julia K Lutz
- Department of Chemistry, Philipps-Universität Marburg, Hans-Meerwein-Strasse 4, 35032 Marburg, Germany
| | - Ulrich Tallarek
- Department of Chemistry, Philipps-Universität Marburg, Hans-Meerwein-Strasse 4, 35032 Marburg, Germany
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5
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Trebel N, Höltzel A, Steinhoff A, Tallarek U. Insights from molecular simulations about dead time markers in reversed-phase liquid chromatography. J Chromatogr A 2021; 1640:461958. [PMID: 33582514 DOI: 10.1016/j.chroma.2021.461958] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2020] [Revised: 01/28/2021] [Accepted: 01/29/2021] [Indexed: 11/16/2022]
Abstract
Among the most popular compounds to estimate the hold-up time in reversed-phase liquid chromatography (RPLC) are acetone and uracil, which are considered as too small and too polar, respectively, for retention by the hydrophobic stationary phase, although their observed elution behavior does not fully support this assumption. We investigate how acetone and uracil as solutes interact with the chromatographic interface through molecular dynamics simulations in an RPLC mesopore model of a silica-supported, endcapped, C18 phase equilibrated with a water (W)‒acetonitrile (ACN) mobile phase. The simulation results provide a molecular-level explanation for the observed elution behavior of acetone and uracil, but also question whether true dead time markers for RPLC exist. Both solutes have a density maximum in the interfacial region in addition to a low presence in the bonded-phase region, but these density peaks clearly differ from the adsorption and partitioning peaks of true analytes. Acetone partially behaves like a co-solvent of ACN and partially like the analyte acetophenone. Like ACN, acetone can be found in the first and second layer of solvent molecules at the silica surface; like acetophenone, acetone adsorbs to the bonded-phase chains by orienting its polar group to the bulk region to sustain hydrogen bonds with W molecules. Uracil behavior is governed by a need for extensive hydrogen-bond coordination by W molecules. Uracil adsorbs to the very edge of the bonded-phase chains, on the bulk-region side of the ACN density maximum in the interfacial region. Further penetration into the chains is prevented by the absence of W molecules, which are not found deeper in the bonded phase, except at the silica surface. Contrary to true analytes, accumulation of uracil and acetone in the interfacial region ceases at an equimolar presence of W and ACN in the mobile phase (at 70‒80% ACN volume fraction). Uracil achieves a closer approximation of the stationary-phase limit than acetone, but carries the risk of HILIC retention at high ACN fraction in the mobile phase.
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Affiliation(s)
- Nicole Trebel
- Department of Chemistry, Philipps-Universität Marburg, Hans-Meerwein-Strasse 4, 35032 Marburg, Germany
| | - Alexandra Höltzel
- Department of Chemistry, Philipps-Universität Marburg, Hans-Meerwein-Strasse 4, 35032 Marburg, Germany
| | - Andreas Steinhoff
- Department of Chemistry, Philipps-Universität Marburg, Hans-Meerwein-Strasse 4, 35032 Marburg, Germany
| | - Ulrich Tallarek
- Department of Chemistry, Philipps-Universität Marburg, Hans-Meerwein-Strasse 4, 35032 Marburg, Germany.
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6
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Li Z, Fu Q, Li S, Jin Y, Liang X. Systematic evaluation and optimization of high‐performance liquid chromatography separation of polyoxins. J Sep Sci 2020; 43:3006-3016. [DOI: 10.1002/jssc.202000269] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2020] [Revised: 05/13/2020] [Accepted: 05/15/2020] [Indexed: 11/10/2022]
Affiliation(s)
- Zhidong Li
- Shanghai Key Laboratory of New Drug Design, State Key Laboratory of Bioreactor Engineering, School of PharmacyEast China University of Science and Technology Shanghai P.R. China
| | - Qing Fu
- Shanghai Key Laboratory of New Drug Design, State Key Laboratory of Bioreactor Engineering, School of PharmacyEast China University of Science and Technology Shanghai P.R. China
| | - Shiliang Li
- Shanghai Key Laboratory of New Drug Design, State Key Laboratory of Bioreactor Engineering, School of PharmacyEast China University of Science and Technology Shanghai P.R. China
| | - Yu Jin
- Shanghai Key Laboratory of New Drug Design, State Key Laboratory of Bioreactor Engineering, School of PharmacyEast China University of Science and Technology Shanghai P.R. China
| | - Xinmiao Liang
- Shanghai Key Laboratory of New Drug Design, State Key Laboratory of Bioreactor Engineering, School of PharmacyEast China University of Science and Technology Shanghai P.R. China
- Key Laboratory of Separation Science for Analytical Chemistry, Key Laboratory of Natural Medicine, Liaoning Province, Dalian Institute of Chemical PhysicsChinese Academy of Sciences Dalian P.R. China
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8
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Žuvela P, Skoczylas M, Jay Liu J, Ba Czek T, Kaliszan R, Wong MW, Buszewski B, Héberger K. Column Characterization and Selection Systems in Reversed-Phase High-Performance Liquid Chromatography. Chem Rev 2019; 119:3674-3729. [PMID: 30604951 DOI: 10.1021/acs.chemrev.8b00246] [Citation(s) in RCA: 143] [Impact Index Per Article: 28.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Reversed-phase high-performance liquid chromatography (RP-HPLC) is the most popular chromatographic mode, accounting for more than 90% of all separations. HPLC itself owes its immense popularity to it being relatively simple and inexpensive, with the equipment being reliable and easy to operate. Due to extensive automation, it can be run virtually unattended with multiple samples at various separation conditions, even by relatively low-skilled personnel. Currently, there are >600 RP-HPLC columns available to end users for purchase, some of which exhibit very large differences in selectivity and production quality. Often, two similar RP-HPLC columns are not equally suitable for the requisite separation, and to date, there is no universal RP-HPLC column covering a variety of analytes. This forces analytical laboratories to keep a multitude of diverse columns. Therefore, column selection is a crucial segment of RP-HPLC method development, especially since sample complexity is constantly increasing. Rationally choosing an appropriate column is complicated. In addition to the differences in the primary intermolecular interactions with analytes of the dispersive (London) type, individual columns can also exhibit a unique character owing to specific polar, hydrogen bond, and electron pair donor-acceptor interactions. They can also vary depending on the type of packing, amount and type of residual silanols, "end-capping", bonding density of ligands, and pore size, among others. Consequently, the chromatographic performance of RP-HPLC systems is often considerably altered depending on the selected column. Although a wide spectrum of knowledge is available on this important subject, there is still a lack of a comprehensive review for an objective comparison and/or selection of chromatographic columns. We aim for this review to be a comprehensive, authoritative, critical, and easily readable monograph of the most relevant publications regarding column selection and characterization in RP-HPLC covering the past four decades. Future perspectives, which involve the integration of state-of-the-art molecular simulations (molecular dynamics or Monte Carlo) with minimal experiments, aimed at nearly "experiment-free" column selection methodology, are proposed.
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Affiliation(s)
- Petar Žuvela
- Department of Chemistry , National University of Singapore , Singapore 117543 , Singapore
| | - Magdalena Skoczylas
- Department of Environmental Chemistry and Bioanalytics, Center for Modern Interdisciplinary Technologies , Nicolaus Copernicus University , Wileńska 4 , 87-100 Toruń , Poland
| | - J Jay Liu
- Department of Chemical Engineering , Pukyong National University , 365 Sinseon-ro , Nam-gu, 48-513 Busan , Korea
| | | | | | - Ming Wah Wong
- Department of Chemistry , National University of Singapore , Singapore 117543 , Singapore
| | - Bogusław Buszewski
- Department of Environmental Chemistry and Bioanalytics, Center for Modern Interdisciplinary Technologies , Nicolaus Copernicus University , Wileńska 4 , 87-100 Toruń , Poland
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9
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El Hage K, Bemish RJ, Meuwly M. From in silica to in silico: retention thermodynamics at solid–liquid interfaces. Phys Chem Chem Phys 2018; 20:18610-18622. [DOI: 10.1039/c8cp02899k] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The dynamics of solvated molecules at the solid/liquid interface is essential for a molecular-level understanding for the solution thermodynamics in reversed phase liquid chromatography (RPLC).
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Affiliation(s)
- Krystel El Hage
- Department of Chemistry
- University of Basel
- CH-4056 Basel
- Switzerland
| | - Raymond J. Bemish
- Air Force Research Laboratory
- Space Vehicles Directorate
- Kirtland AFB
- USA
| | - Markus Meuwly
- Department of Chemistry
- University of Basel
- CH-4056 Basel
- Switzerland
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10
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El Hage K, Gupta PK, Bemish R, Meuwly M. Molecular Mechanisms Underlying Solute Retention at Heterogeneous Interfaces. J Phys Chem Lett 2017; 8:4600-4607. [PMID: 28872324 DOI: 10.1021/acs.jpclett.7b01966] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Despite considerable effort, a molecular-level understanding of the mechanisms governing adsorption/desorption in reversed-phase liquid chromatography is still lacking. This impedes rational design of columns and the development of reliable, computationally more efficient approaches to predict the selectivity of a particular column design. Using state-of-the art, validated force fields and free-energy simulations, the adsorption thermodynamics of benzene derivatives is investigated in atomistic detail and provides a quantitative microscopic understanding of retention when compared with experimental data. It is found that pure partitioning or pure adsorption is rather the exception than the rule. Typically, a pronounced ∼1 kcal/mol stabilization on the surface is accompanied by a broad trough indicative of partitioning before the probe molecule incorporates into the mobile phase. The present findings provide a quantitative and rational basis to develop improved effective, coarse-grained computational models and to design columns for specific applications.
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Affiliation(s)
- Krystel El Hage
- Department of Chemistry, University of Basel , Klingelbergstrasse 80, 4056 Basel, Switzerland
| | - Prashant Kumar Gupta
- Department of Chemistry, University of Basel , Klingelbergstrasse 80, 4056 Basel, Switzerland
| | - Raymond Bemish
- Air Force Research Laboratory, Space Vehicles Directorate , Kirtland AFB, New Mexico 87117, United States
| | - Markus Meuwly
- Department of Chemistry, University of Basel , Klingelbergstrasse 80, 4056 Basel, Switzerland
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11
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Farzaneh A, DeJaco RF, Ohlin L, Holmgren A, Siepmann JI, Grahn M. Comparative Study of the Effect of Defects on Selective Adsorption of Butanol from Butanol/Water Binary Vapor Mixtures in Silicalite-1 Films. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2017; 33:8420-8427. [PMID: 28767246 DOI: 10.1021/acs.langmuir.7b02097] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
A promising route for sustainable 1-butanol (butanol) production is ABE (acetone, butanol, ethanol) fermentation. However, recovery of the products is challenging because of the low concentrations obtained in the aqueous solution, thus hampering large-scale production of biobutanol. Membrane and adsorbent-based technologies using hydrophobic zeolites are interesting alternatives to traditional separation techniques (e.g., distillation) for energy-efficient separation of butanol from aqueous mixtures. To maximize the butanol over water selectivity of the material, it is important to reduce the number of hydrophilic adsorption sites. This can, for instance, be achieved by reducing the density of lattice defect sites where polar silanol groups are found. The density of silanol defects can be reduced by preparing the zeolite at neutral pH instead of using traditional synthesis solutions with high pH. In this work, binary adsorption of butanol and water in two silicalite-1 films was studied using in situ attenuated total reflectance-Fourier transform infrared (ATR-FTIR) spectroscopy under equal experimental conditions. One of the films was prepared in fluoride medium, whereas the other one was prepared at high pH using traditional synthesis conditions. The amounts of water and butanol adsorbed from binary vapor mixtures of varying composition were determined at 35 and 50 °C, and the corresponding adsorption selectivities were also obtained. Both samples showed very high selectivities (100-23 000) toward butanol under the conditions studied. The sample having low density of defects, in general, showed ca. a factor 10 times higher butanol selectivity than the sample having a higher density of defects at the same experimental conditions. This difference was due to a much lower adsorption of water in the sample with low density of internal defects. Analysis of molecular simulation trajectories provides insights on the local selectivities in the zeolite channel network and at the film surface.
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Affiliation(s)
| | - Robert F DeJaco
- Department of Chemical Engineering and Materials Science and Department of Chemistry and Chemical Theory Center, University of Minnesota , Minneapolis, Minnesota 55455, United States
| | - Lindsay Ohlin
- Chemical Technology, Luleå University of Technology , SE-971 87 Luleå, Sweden
| | - Allan Holmgren
- Chemical Technology, Luleå University of Technology , SE-971 87 Luleå, Sweden
| | - J Ilja Siepmann
- Department of Chemical Engineering and Materials Science and Department of Chemistry and Chemical Theory Center, University of Minnesota , Minneapolis, Minnesota 55455, United States
| | - Mattias Grahn
- Chemical Technology, Luleå University of Technology , SE-971 87 Luleå, Sweden
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12
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Tong HF, Cavallotti C, Yao SJ, Lin DQ. Molecular insight into protein binding orientations and interaction modes on hydrophobic charge-induction resin. J Chromatogr A 2017; 1512:34-42. [DOI: 10.1016/j.chroma.2017.06.071] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2017] [Revised: 06/15/2017] [Accepted: 06/29/2017] [Indexed: 11/28/2022]
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13
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Hydrophobicity of carbohydrates and related hydroxy compounds. Carbohydr Res 2017; 446-447:101-112. [PMID: 28554012 DOI: 10.1016/j.carres.2017.04.019] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2017] [Revised: 04/13/2017] [Indexed: 11/21/2022]
Abstract
The hydrophobic interaction of carbohydrates and other hydroxy compounds with a C18-modified silica gel column was measured with pure water as eluent, thereby expanding the range of measurements already published. The interaction is augmented by structure strengthening salts and decreasing temperature. Although the interaction of the solute with the hydrophobic interface is expected to only imperfectly reflect its state in aqueous bulk solution, the retention can be correlated to hydration numbers calculated from molecular mechanics studies given in the literature. No correlation can be established towards published hydration numbers obtained by physical methods (isentropic compressibility, O-17 NMR relaxation, terahertz spectroscopy, and viscosity). The hydrophobicity is discussed with respect to the chemical structure. It increases with the fraction and size of hydrophobic molecular surface regions.
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14
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Bocian S. Solvation processes in liquid chromatography: The importance and measurements. J LIQ CHROMATOGR R T 2016. [DOI: 10.1080/10826076.2016.1242494] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Affiliation(s)
- Szymon Bocian
- Chair of Environmental Chemistry and Bioanalytics, Faculty of Chemistry, Nicolaus Copernicus University, Toruń, Poland
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15
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Gupta PK, Meuwly M. Structure and Dynamics of Water/Methanol Mixtures at Hydroxylated Silica Interfaces Relevant to Chromatography. Chemphyschem 2016; 17:2938-44. [DOI: 10.1002/cphc.201600180] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2016] [Revised: 04/29/2016] [Indexed: 11/11/2022]
Affiliation(s)
- Prashant Kumar Gupta
- Department of Chemistry; University of Basel; Klingelbergstrasse 80 CH-4056 Basel Switzerland
- Lehrstuhl für Theoretische Chemie; Ruhr-Universität Bochum; Universitätsstraße 150 D-44801 Bochum Germany
| | - Markus Meuwly
- Department of Chemistry; University of Basel; Klingelbergstrasse 80 CH-4056 Basel Switzerland
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16
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Gritti F. Determination of the solvent density profiles across mesopores of silica-C18 bonded phases in contact with acetonitrile/water mixtures: A semi-empirical approach. J Chromatogr A 2015; 1410:90-8. [DOI: 10.1016/j.chroma.2015.07.073] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2015] [Revised: 07/13/2015] [Accepted: 07/18/2015] [Indexed: 11/29/2022]
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17
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Mabry JN, Schwartz DK. Tuning the Flight Length of Molecules Diffusing on a Hydrophobic Surface. J Phys Chem Lett 2015; 6:2065-2069. [PMID: 26266503 DOI: 10.1021/acs.jpclett.5b00799] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Transport at solid-liquid interfaces is critical to self-assembly, biosensing, and heterogeneous catalysis, but surface diffusion remains difficult to characterize and rationally manipulate, due to the inherent heterogeneity of adsorption on solid surfaces. Using single-molecule tracking, we characterized the diffusion of a fluorescent long-chain surfactant on a hydrophobic surface, which involved periods of confinement alternating with bulk-mediated "flights". The concentration of methanol in solution was varied to tune the strength of the hydrophobic surface-molecule interaction. The frequency of confinement had a nonmonotonic dependence on methanol concentration that reflected the relative influence of anomalously strong adsorption sites. By carefully accounting for the effect of this surface heterogeneity, we demonstrated that flight lengths increased monotonically as the hydrophobic attraction decreased, in agreement with theoretical predictions for bulk-mediated surface diffusion. The theory provided an accurate description of surface diffusion, despite the system being heterogeneous, and can be leveraged to optimize molecular search and assembly processes.
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Affiliation(s)
- Joshua N Mabry
- Department of Chemical and Biological Engineering, University of Colorado Boulder, Boulder, Colorado 80309-0596, United States
| | - Daniel K Schwartz
- Department of Chemical and Biological Engineering, University of Colorado Boulder, Boulder, Colorado 80309-0596, United States
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18
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Borówko M, Sokołowski S, Staszewski T. Adsorption on chemically bonded chain layers with embedded active groups. Mol Phys 2014. [DOI: 10.1080/00268976.2014.962636] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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19
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Borówko M, Sokołowski S, Staszewski T. Adsorption-induced changes of the structure of the tethered chain layers in a simple fluid. J Chem Phys 2014; 140:234904. [PMID: 24952565 DOI: 10.1063/1.4883336] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
We use density functional theory to study the influence of fluid adsorption on the structure of grafted chain layer. The chains are modeled as freely jointed spheres. The chain segments and spherical molecules of the fluid interact via the Lennard-Jones potential. The fluid molecules are attracted by the substrate. We calculate the excess adsorption isotherms, the average height of tethered chains, and the force acting on selected segments of the chains. The parameters that were varied include the length of grafted chains, the grafting density, the parameters characterizing fluid-chain and fluid-surface interactions, the bulk fluid density, and temperature. We show that depending on the density of the bulk fluid the height of the bonded layer increases, remains constant, or decreases with increasing temperature.
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Affiliation(s)
- M Borówko
- Department for the Modelling of Physico-Chemical Processes, Maria Curie-Skłodowska University, 20-031 Lublin, Poland
| | - S Sokołowski
- Department for the Modelling of Physico-Chemical Processes, Maria Curie-Skłodowska University, 20-031 Lublin, Poland
| | - T Staszewski
- Department for the Modelling of Physico-Chemical Processes, Maria Curie-Skłodowska University, 20-031 Lublin, Poland
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20
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Bassanese DN, Soliven A, Stevenson PG, Dennis GR, Barnett NW, Shalliker RA, Conlan XA. Investigating retention characteristics of a mixed-mode stationary phase and the enhancement of monolith selectivity for high-performance liquid chromatography. J Sep Sci 2014; 37:1937-43. [DOI: 10.1002/jssc.201400201] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2014] [Revised: 04/29/2014] [Accepted: 04/30/2014] [Indexed: 11/11/2022]
Affiliation(s)
- Danielle N. Bassanese
- Faculty of Science, Engineering and Built Environment, Centre for Chemistry and Biotechnology; Deakin University; Geelong Victoria Australia
| | - Arianne Soliven
- Australian Centre for Research on Separation Science (ACROSS); School of Science and Health, University of Western Sydney (Parramatta); Sydney NSW Australia
| | - Paul G. Stevenson
- Faculty of Science, Engineering and Built Environment, Centre for Chemistry and Biotechnology; Deakin University; Geelong Victoria Australia
| | - Gary R. Dennis
- Australian Centre for Research on Separation Science (ACROSS); School of Science and Health, University of Western Sydney (Parramatta); Sydney NSW Australia
| | - Neil W. Barnett
- Faculty of Science, Engineering and Built Environment, Centre for Chemistry and Biotechnology; Deakin University; Geelong Victoria Australia
| | - Ross A. Shalliker
- Australian Centre for Research on Separation Science (ACROSS); School of Science and Health, University of Western Sydney (Parramatta); Sydney NSW Australia
| | - Xavier A. Conlan
- Faculty of Science, Engineering and Built Environment, Centre for Chemistry and Biotechnology; Deakin University; Geelong Victoria Australia
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21
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Borówko M, Sokołowski S, Staszewski T. Terminally Grafted Chain Layers in Oligomer–Monomer Solutions: Predictions from a Density Functional Theory. J Phys Chem B 2013; 117:10293-303. [DOI: 10.1021/jp4027546] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Affiliation(s)
- M. Borówko
- Department
for the Modeling
of Physico-Chemical Processes, Maria Curie-Skłodowska University, 20-031 Lublin, Poland
| | - S. Sokołowski
- Department
for the Modeling
of Physico-Chemical Processes, Maria Curie-Skłodowska University, 20-031 Lublin, Poland
| | - T. Staszewski
- Department
for the Modeling
of Physico-Chemical Processes, Maria Curie-Skłodowska University, 20-031 Lublin, Poland
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22
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Liu K, Aggarwal P, Lawson JS, Tolley HD, Lee ML. Organic monoliths for high-performance reversed-phase liquid chromatography. J Sep Sci 2013; 36:2767-81. [DOI: 10.1002/jssc.201300431] [Citation(s) in RCA: 54] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2013] [Revised: 05/31/2013] [Accepted: 05/31/2013] [Indexed: 11/09/2022]
Affiliation(s)
- Kun Liu
- Department of Chemistry and Biochemistry; Brigham Young University; Provo UT USA
| | - Pankaj Aggarwal
- Department of Chemistry and Biochemistry; Brigham Young University; Provo UT USA
| | - John S. Lawson
- Department of Statistics; Brigham Young University; Provo UT USA
| | - H. Dennis Tolley
- Department of Statistics; Brigham Young University; Provo UT USA
| | - Milton L. Lee
- Department of Chemistry and Biochemistry; Brigham Young University; Provo UT USA
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23
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Undin T, Samuelsson J, Törncrona A, Fornstedt T. Evaluation of a combined linear-nonlinear approach for column characterization using modern alkaline-stable columns as model. J Sep Sci 2013; 36:1753-61. [DOI: 10.1002/jssc.201201132] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2012] [Revised: 02/25/2013] [Accepted: 03/18/2013] [Indexed: 11/09/2022]
Affiliation(s)
- Torgny Undin
- Department of Chemistry - BMC, Uppsala University; Uppsala; Sweden
| | - Jörgen Samuelsson
- Department of Engineering and Chemical Sciences; Karlstad University; Karlstad; Sweden
| | | | - Torgny Fornstedt
- Department of Engineering and Chemical Sciences; Karlstad University; Karlstad; Sweden
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24
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Lindsey RK, Rafferty JL, Eggimann BL, Siepmann JI, Schure MR. Molecular simulation studies of reversed-phase liquid chromatography. J Chromatogr A 2013; 1287:60-82. [PMID: 23489490 DOI: 10.1016/j.chroma.2013.02.040] [Citation(s) in RCA: 79] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2013] [Revised: 02/10/2013] [Accepted: 02/11/2013] [Indexed: 11/28/2022]
Abstract
Over the past 20 years, molecular simulation methods have been applied to the modeling of reversed-phase liquid chromatography (RPLC). The purpose of these simulations was to provide a molecular-level understanding of: (i) the structure and dynamics of the bonded phase and its interface with the mobile phase, (ii) the interactions of analytes with the bonded phase, and (iii) the retention mechanism for different analytes. However, the investigation of chromatographic systems poses significant challenges for simulations with respect to the accuracy of the molecular mechanics force fields and the efficiency of the sampling algorithms. This review discusses a number of aspects concerning molecular simulation studies of RPLC systems including the historical development of the subject, the background needed to understand the two prevalent techniques, molecular dynamics (MD) and Monte Carlo (MC) methods, and the wealth of insight provided by these simulations. Examples from the literature employing MD approaches and from the authors' laboratory using MC methods are discussed. The former can provide information on chain dynamics and transport properties, whereas the latter techniques are uniquely suited for the investigation of phase and sorption equilibria that underly RPLC retention, and both can be used to elucidate the bonded-chain conformations and solvent distributions.
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Affiliation(s)
- Rebecca K Lindsey
- Department of Chemistry and Chemical Theory Center, University of Minnesota, 207 Pleasant Street SE, Minneapolis, MN 55455-0431, USA
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25
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Borówko M, Sokołowski S, Staszewski T. Adsorption from Oligomer–Monomer Solutions on the Surfaces Modified with End-Grafted Chains. J Phys Chem B 2012; 116:12842-9. [DOI: 10.1021/jp305624n] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Affiliation(s)
- M. Borówko
- Department for the Modeling
of Physico-Chemical
Processes, Maria Curie-Skłodowska University, 20-031 Lublin, Poland
| | - S. Sokołowski
- Department for the Modeling
of Physico-Chemical
Processes, Maria Curie-Skłodowska University, 20-031 Lublin, Poland
| | - T. Staszewski
- Department for the Modeling
of Physico-Chemical
Processes, Maria Curie-Skłodowska University, 20-031 Lublin, Poland
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26
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Borówko M, Sokołowski S, Staszewski T. Adsorption from Binary Solutions on the Polymer-Tethered Surfaces. J Phys Chem B 2012; 116:3115-24. [DOI: 10.1021/jp300114y] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Affiliation(s)
- M. Borówko
- Department for the Modeling
of Physico-Chemical
Processes, Maria Curie-Skłodowska University, 20-031 Lublin, Poland
| | - S. Sokołowski
- Department for the Modeling
of Physico-Chemical
Processes, Maria Curie-Skłodowska University, 20-031 Lublin, Poland
| | - T. Staszewski
- Department for the Modeling
of Physico-Chemical
Processes, Maria Curie-Skłodowska University, 20-031 Lublin, Poland
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27
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Rafferty JL, Siepmann JI, Schure MR. A molecular simulation study of the effects of stationary phase and solute chain length in reversed-phase liquid chromatography. J Chromatogr A 2012; 1223:24-34. [DOI: 10.1016/j.chroma.2011.11.039] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2011] [Revised: 11/17/2011] [Accepted: 11/20/2011] [Indexed: 10/15/2022]
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28
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Rafferty JL, Siepmann JI, Schure MR. Molecular simulations of retention in chromatographic systems: use of biased Monte Carlo techniques to access multiple time and length scales. Top Curr Chem (Cham) 2012; 307:181-200. [PMID: 21898207 DOI: 10.1007/128_2011_210] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
The use of configurational-bias Monte Carlo simulations in the Gibbs ensemble allows for the sampling of phenomena that occur on vastly different time and length scales. In this review, applications of this simulation approach to probe retention in gas and reversed-phase liquid chromatographic systems are discussed. These simulations provide an unprecedented view of the retention processes at the molecular-level and show excellent agreement with experimental retention data.
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Affiliation(s)
- Jake L Rafferty
- Department of Chemistry and Chemical Theory Center, University of Minnesota, 207 Pleasant Street SE, Minneapolis, MN 55455-0431, USA
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29
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Rafferty JL, Siepmann JI, Schure MR. Retention mechanism for polycyclic aromatic hydrocarbons in reversed-phase liquid chromatography with monomeric stationary phases. J Chromatogr A 2011; 1218:9183-93. [DOI: 10.1016/j.chroma.2011.10.043] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2011] [Revised: 10/11/2011] [Accepted: 10/17/2011] [Indexed: 10/15/2022]
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30
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Borówko M, Sokołowski S, Staszewski T. Adsorption of oligomers on the polymer-tethered surfaces. J Colloid Interface Sci 2011; 356:267-76. [DOI: 10.1016/j.jcis.2011.01.023] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2010] [Revised: 01/05/2011] [Accepted: 01/05/2011] [Indexed: 10/18/2022]
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31
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Rafferty JL, Siepmann JI, Schure MR. Mobile phase effects in reversed-phase liquid chromatography: A comparison of acetonitrile/water and methanol/water solvents as studied by molecular simulation. J Chromatogr A 2011; 1218:2203-13. [DOI: 10.1016/j.chroma.2011.02.012] [Citation(s) in RCA: 68] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2010] [Revised: 01/28/2011] [Accepted: 02/05/2011] [Indexed: 11/16/2022]
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32
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Li Y, Liu D, Wang P, Zhou Z. Computational study of enantioseparation by amylose tris(3,5-dimethylphenylcarbamate)-based chiral stationary phase. J Sep Sci 2011; 33:3245-55. [PMID: 20839235 DOI: 10.1002/jssc.201000266] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
The mechanism of chiral separation on amylose tris(3,5-dimethylphenylcarbamate) is studied with docking simulations of enantiomers by molecular dynamics. All-atom models of amylose tris(3,5-dimethylphenylcarbamate) on the modified silica gel surface were constructed for the docking simulations of metalaxyl and benalaxyl. The elution orders and energetic differences were also predicted based on the intermolecular interactions, which were in agreement with the experimental results. The radial distribution function was employed to analyze the structural features of the enantiomer-chiral stationary phase complex and used to elucidate the mechanism of chiral separation. The separation of metalaxyl and benalaxyl is mainly controlled by the hydrogen bond. And the binding sites had slight differences for the pair of enantiomers, but obvious differences between different chemicals.
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Affiliation(s)
- Yangyang Li
- Department of Applied Chemistry, College of Science, China Agricultural University, Beijing, PR China
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33
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Borówko M, Sokołowski S, Staszewski T. A density functional approach to retention in chromatography with chemically bonded phases. J Chromatogr A 2011; 1218:711-20. [DOI: 10.1016/j.chroma.2010.12.029] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2010] [Revised: 12/06/2010] [Accepted: 12/07/2010] [Indexed: 10/18/2022]
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34
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Mitchell CR, Benz NJ, Zhang S. Characterization of stationary phases by a linear solvation energy relationship utilizing supercritical fluid chromatography. J Sep Sci 2010; 33:3060-7. [DOI: 10.1002/jssc.201000371] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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35
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Buszewski B, Bocian S, Nowaczyk A. Modeling solvation on the chemically modified silica surfaces. J Sep Sci 2010; 33:2060-8. [DOI: 10.1002/jssc.201000101] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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36
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Buszewski B, Bocian S, Rychlicki G, Vajda P, Felinger A. Study of solvent adsorption on chemically bonded stationary phases by microcalorimetry and liquid chromatography. J Colloid Interface Sci 2010; 349:620-5. [PMID: 20584530 DOI: 10.1016/j.jcis.2010.05.096] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2010] [Revised: 05/28/2010] [Accepted: 05/29/2010] [Indexed: 11/30/2022]
Abstract
A detailed, molecular-level description of the sorption mechanism in reversed-phase liquid chromatography is of great interest to analytical chemists. For this purpose, solvent adsorption in the octadecyl stationary bonded phase was investigated. Preferential adsorption of solvents from an acetonitrile-water and methanol-water mobile phase was measured on a series of non-end-capped octadecyl bonded phases with different coverage densities of bonded ligands using the minor disturbance method. For a comparison, a microcalorimetric study of organic solvent adsorption on the stationary phase was executed. The results from the excess isotherm measurement agree well with the experimental measurement of the heat of immersion of the bonded stationary phases by the test solvents. The microcalorimetric measurement is another method for determination of solvation processes of the stationary phases. Changes of the heat of immersion provide information about the surface accessibility for interaction with solvent molecules. The increase of the stationary phase coverage density reduces the free space between bonded chains and penetration of solvent between organic chains.
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Affiliation(s)
- Bogusław Buszewski
- Department of Environmental Chemistry & Bioanalytics, Faculty of Chemistry, Nicolaus Copernicus University, Gagarin 7 St., 87-100 Torun, Poland.
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37
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Bocian S, Vajda P, Felinger A, Buszewski B. Effect of End-Capping and Surface Coverage on the Mechanism of Solvent Adsorption. Chromatographia 2010. [DOI: 10.1365/s10337-010-1522-0] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
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38
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Zhang L, Sun Y. Molecular simulation of adsorption and its implications to protein chromatography: A review. Biochem Eng J 2010. [DOI: 10.1016/j.bej.2009.12.003] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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39
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Zhang L, Zhao G, Sun Y. Effects of Ligand Density on Hydrophobic Charge Induction Chromatography: Molecular Dynamics Simulation. J Phys Chem B 2010; 114:2203-11. [DOI: 10.1021/jp903852c] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Lin Zhang
- Department of Biochemical Engineering, School of Chemical Engineering and Technology, Tianjin University, Tianjin 300072, China
| | - Guofeng Zhao
- Department of Biochemical Engineering, School of Chemical Engineering and Technology, Tianjin University, Tianjin 300072, China
| | - Yan Sun
- Department of Biochemical Engineering, School of Chemical Engineering and Technology, Tianjin University, Tianjin 300072, China
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40
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Hu Z, Jiang J. Separation of amino acids in glucose isomerase crystal: Insight from molecular dynamics simulations. J Chromatogr A 2009; 1216:5122-9. [DOI: 10.1016/j.chroma.2009.04.076] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2009] [Revised: 04/21/2009] [Accepted: 04/24/2009] [Indexed: 10/20/2022]
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41
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Borówko M, Rżysko W, Sokołowski S, Staszewski T. Density Functional Approach to Adsorption and Retention of Spherical Molecules on Surfaces Modified with End-Grafted Polymers. J Phys Chem B 2009; 113:4763-70. [DOI: 10.1021/jp811143n] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Affiliation(s)
- M. Borówko
- Department for the Modeling of Physico-Chemical Processes, Maria Curie-Skłodowska University, 20-031 Lublin, Poland
| | - W. Rżysko
- Department for the Modeling of Physico-Chemical Processes, Maria Curie-Skłodowska University, 20-031 Lublin, Poland
| | - S. Sokołowski
- Department for the Modeling of Physico-Chemical Processes, Maria Curie-Skłodowska University, 20-031 Lublin, Poland
| | - T. Staszewski
- Department for the Modeling of Physico-Chemical Processes, Maria Curie-Skłodowska University, 20-031 Lublin, Poland
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42
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The effects of chain length, embedded polar groups, pressure, and pore shape on structure and retention in reversed-phase liquid chromatography: Molecular-level insights from Monte Carlo simulations. J Chromatogr A 2009; 1216:2320-31. [DOI: 10.1016/j.chroma.2008.12.088] [Citation(s) in RCA: 56] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2008] [Revised: 12/22/2008] [Accepted: 12/29/2008] [Indexed: 11/22/2022]
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43
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Wang M, Mallette J, Parcher JF. Sorption Isotherms of Ternary Eluents in Reversed-Phase Liquid Chromatography. Anal Chem 2009; 81:984-90. [DOI: 10.1021/ac8020104] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Mei Wang
- Chemistry Department, University of Mississippi, University, Mississippi 38677
| | - Jennifer Mallette
- Chemistry Department, University of Mississippi, University, Mississippi 38677
| | - Jon F. Parcher
- Chemistry Department, University of Mississippi, University, Mississippi 38677
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44
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Rafferty JL, Siepmann JI, Schure MR. Influence of bonded-phase coverage in reversed-phase liquid chromatography via molecular simulation. J Chromatogr A 2008; 1204:20-7. [DOI: 10.1016/j.chroma.2008.07.038] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2008] [Revised: 06/24/2008] [Accepted: 07/04/2008] [Indexed: 11/16/2022]
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