1
|
V G, Basuri PP, Sahini K, C N N. Retention behaviour of analytes in reversed phase high performance liquid chromatography - A review. Biomed Chromatogr 2022:e5482. [PMID: 35962484 DOI: 10.1002/bmc.5482] [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: 04/06/2022] [Revised: 08/08/2022] [Accepted: 08/10/2022] [Indexed: 11/10/2022]
Abstract
The understanding of principles that drive the separation in reversed phase chromatography plays an important role in the prediction of elution of solutes in RP-HPLC. The separation in RP-HPLC is based on the principle of adsorption and partition. In addition, the log P value, pKa value of the drug, chromatographic parameters like mobile phase pH, buffer concentration, organic modifier and mobile phase additives also influence the retention and selectivity of the analyte. It is found that hydrophobic, electrostatic, hydrogen bonding and other specific interactions between the stationary phase and the solutes along with the hydrophobicity of an analyte molecule (log P) modify the retention behaviour of the analytes. This article gives special attention to the influence of ionization and ion interaction on the separation of analytes. The drug molecules with different log P value containing protonated and deprotonated acids, bases and zwitterions are selected as examples and this article addresses various issues related to method development, relationships between analyte retention and mobile phase pH and pKa value of the analyte. The advances in this regard, with highlights on topics such as mechanisms of retention and various factors that influence the retention behaviour of analytes is also updated with suitable examples.
Collapse
Affiliation(s)
- Ganesh V
- Department of Pharmaceutical analysis, C. L. Baid Metha College of pharmacy, Chennai, India
| | - P Poorna Basuri
- Department of Pharmaceutical analysis, C. L. Baid Metha College of pharmacy, Chennai, India
| | - K Sahini
- Department of Pharmaceutical analysis, C. L. Baid Metha College of pharmacy, Chennai, India
| | - Nalini C N
- Department of Pharmaceutical analysis, C. L. Baid Metha College of pharmacy, Chennai, India
| |
Collapse
|
2
|
Ailawar S, Hunoor A, Basu D, Rudzinski B, Burel L, Millet JMM, Miller JT, Edmiston PL, Ozkan US. Aqueous Phase Hydrodechlorination of Trichloroethylene using Pd Supported on Swellable Organically Modified Silica (SOMS): Effect of Support Derivatization. J Catal 2022. [DOI: 10.1016/j.jcat.2022.04.031] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
|
3
|
Luo C, DeStefano JJ, Langlois TJ, Boyes BE, Schuster SA, Godinho JM. Fundamental to achieving fast separations with high efficiency: A review of chromatography with superficially porous particles. Biomed Chromatogr 2021; 35:e5087. [PMID: 33566360 DOI: 10.1002/bmc.5087] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2020] [Revised: 01/26/2021] [Accepted: 02/05/2021] [Indexed: 01/16/2023]
Abstract
Types of particles have been fundamental to LC separation technology for many years. Originally, LC columns were packed with large-diameter (>100 μm) calcium carbonate, silica gel, or alumina particles that prohibited fast mobile-phase speeds because of the slow diffusion of sample molecules inside deep pores. During the birth of HPLC in the 1960s, superficially porous particles (SPP, ≥30 μm) were developed as the first high-speed stationary-phase support structures commercialized, which permitted faster mobile-phase flowrates due to the fast movement of sample molecules in/out of the thin shells. These initial SPPs were displaced by smaller totally porous particles (TPP) in the mid-1970s. But SPP history repeated when UHPLC emerged in the 2000s. Stationary-phase support structures made from sub-3-μm SPPs were introduced to chromatographers in 2006. The initial purpose of this modern SPP was to enable chromatographers to achieve fast separations with high efficiency using conventional HPLCs. Later, the introduction of sub-2-μm SPPs with UHPLC instruments pushed the separation speed and efficiency to a very fast zone. This review aims at providing readers a comprehensive and up-to-date view on the advantages of SPP materials over TPPs historically and theoretically from the material science angle.
Collapse
Affiliation(s)
- Chuping Luo
- Advanced Materials Technology, Inc, Wilmington, Delaware, USA
| | | | | | - Barry E Boyes
- Advanced Materials Technology, Inc, Wilmington, Delaware, USA
| | | | | |
Collapse
|
4
|
Cabooter D, Song H, Makey D, Sadriaj D, Dittmann M, Stoll D, Desmet G. Measurement and modelling of the intra-particle diffusion and b-term in reversed-phase liquid chromatography. J Chromatogr A 2020; 1637:461852. [PMID: 33412290 DOI: 10.1016/j.chroma.2020.461852] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2020] [Revised: 12/21/2020] [Accepted: 12/23/2020] [Indexed: 12/11/2022]
Abstract
In an ongoing effort to better understand the underlying mechanisms of band broadening in particle-packed reversed-phase liquid chromatography columns, new models for intra-particle diffusion, representing an adsorption- and partition-type retention behavior, are proposed. These models assume the mesoporous zone inside the particles is subdivided in four distinct regions: a fraction f1 filled with bulk mobile phase, a fraction f2 enriched in pure organic modifier extending outside the stationary phase layer, a fraction f3 comprising the liquid surrounding the alkyl chains and a fraction f4 consisting of the stationary phase alkyl chains. Intra-particle diffusion is calculated as a residence time weighted average of the diffusion in these different regions. Experimental procedures and models are proposed to determine the volumes of these four regions and applied to three reversed-phase liquid chromatography columns with different pore sizes (80 Å versus 300 Å) and different stationary phase types (C18 versus C8). The newly proposed models are then applied to predict the intra-particle diffusion of butyrophenone across a wide range of retention factors (1 ≤ k" ≤ 40) in each of these columns. These predictions are compared to experimental data that are extracted from the effective diffusion coefficients of butyrophenone obtained via peak parking experiments. It is demonstrated that both adsorption- and partition-type models for intra-particle diffusion model the actual behavior of the test compound well, and require the determination of only one (partition) or two (adsorption) fitting factors: the obstruction to free movement the analytes experience from the alkyl chains in the retained state (partition and adsorption) and in the unretained state (adsorption). Finally, it is demonstrated that the major contributor to the intra-particle diffusion of retained compounds (k" > 2) is the diffusion these analytes undergo when retained in the organic-modifier enriched zone surrounding the alkyl chains (partition model) or when adsorbed onto the alkyl chains (adsorption model), confirming that surface diffusion plays an important role in the mass transfer of retained compounds in reversed-phase liquid chromatography columns.
Collapse
Affiliation(s)
- Deirdre Cabooter
- University of Leuven (KU Leuven), Department for Pharmaceutical and Pharmacological Sciences, Pharmaceutical Analysis, Herestraat 49, Leuven, Belgium.
| | - Huiying Song
- University of Leuven (KU Leuven), Department for Pharmaceutical and Pharmacological Sciences, Pharmaceutical Analysis, Herestraat 49, Leuven, Belgium
| | - Devin Makey
- Gustavus Adolphus College, Department of Chemistry, 800 West College Avenue, Saint Peter, USA
| | - Donatela Sadriaj
- University of Leuven (KU Leuven), Department for Pharmaceutical and Pharmacological Sciences, Pharmaceutical Analysis, Herestraat 49, Leuven, Belgium
| | - Monika Dittmann
- Agilent Technologies R&D, Hewlett-Packard-Strasse 8, Waldbronn, Germany
| | - Dwight Stoll
- Gustavus Adolphus College, Department of Chemistry, 800 West College Avenue, Saint Peter, USA
| | - Gert Desmet
- Vrije Universiteit Brussel, Department of Chemical Engineering, Pleinlaan 2, 1050 Brussel, Belgium
| |
Collapse
|
5
|
Time-resolved investigation of mesoporous silica microsphere formation using in situ heating optical microscopy. J Colloid Interface Sci 2020; 585:118-125. [PMID: 33279693 DOI: 10.1016/j.jcis.2020.11.087] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2020] [Revised: 11/22/2020] [Accepted: 11/23/2020] [Indexed: 11/24/2022]
Abstract
A fundamental understanding of the drying behavior of droplets containing solids or solutes is important for various industrial applications. However, droplets are typically highly polydisperse and time-resolved imaging data of the process dynamics are often lacking, which makes it difficult to interpret the effects of different drying parameters. Here, the controlled drying of monodisperse emulsion droplets containing colloidal silica nanoparticles and their subsequent assembly into mesoporous silica microspheres (MSMs) is investigated using an optical microscope outfitted with a heating and vacuum stage. Quantitative imaging results on droplet shrinkage and observed contrast are compared with a theoretical mass-transfer model that is based on the droplet number density, solvent characteristics and temperature. The results presented here provide key insights in the time-resolved formation of MSMs and will enable an optimized direct synthesis of monodisperse MSMs for separation applications and beyond.
Collapse
|
6
|
Fortuni B, Inose T, Ricci M, Fujita Y, Van Zundert I, Masuhara A, Fron E, Mizuno H, Latterini L, Rocha S, Uji-I H. Polymeric Engineering of Nanoparticles for Highly Efficient Multifunctional Drug Delivery Systems. Sci Rep 2019; 9:2666. [PMID: 30804375 PMCID: PMC6389875 DOI: 10.1038/s41598-019-39107-3] [Citation(s) in RCA: 93] [Impact Index Per Article: 18.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2018] [Accepted: 01/16/2019] [Indexed: 11/18/2022] Open
Abstract
Most targeting strategies of anticancer drug delivery systems (DDSs) rely on the surface functionalization of nanocarriers with specific ligands, which trigger the internalization in cancer cells via receptor-mediated endocytosis. The endocytosis implies the entrapment of DDSs in acidic vesicles (endosomes and lysosomes) and their eventual ejection by exocytosis. This process, intrinsic to eukaryotic cells, is one of the main drawbacks of DDSs because it reduces the drug bioavailability in the intracellular environment. The escape of DDSs from the acidic vesicles is, therefore, crucial to enhance the therapeutic performance at low drug dose. To this end, we developed a multifunctionalized DDS that combines high specificity towards cancer cells with endosomal escape capabilities. Doxorubicin-loaded mesoporous silica nanoparticles were functionalized with polyethylenimine, a polymer commonly used to induce endosomal rupture, and hyaluronic acid, which binds to CD44 receptors, overexpressed in cancer cells. We show irrefutable proof that the developed DDS can escape the endosomal pathway upon polymeric functionalization. Interestingly, the combination of the two polymers resulted in higher endosomal escape efficiency than the polyethylenimine coating alone. Hyaluronic acid additionally provides the system with cancer targeting capability and enzymatically controlled drug release. Thanks to this multifunctionality, the engineered DDS had cytotoxicity comparable to the pure drug whilst displaying high specificity towards cancer cells. The polymeric engineering here developed enhances the performance of DDS at low drug dose, holding great potential for anticancer therapeutic applications.
Collapse
Affiliation(s)
- Beatrice Fortuni
- KU Leuven, department of Chemistry, Celestijnenlaan 200G-F, Heverlee, 3001, Belgium.
| | - Tomoko Inose
- RIES Hokkaido University, Research Institute for Electronic Science, N20W10, Kita-Ward Sapporo, 0010020, Japan
| | - Monica Ricci
- KU Leuven, department of Chemistry, Celestijnenlaan 200G-F, Heverlee, 3001, Belgium
| | - Yasuhiko Fujita
- Toray Research Center, Inc., 3-3-7, Sonoyama, Otsu, Shiga, 520-8567, Japan
| | - Indra Van Zundert
- KU Leuven, department of Chemistry, Celestijnenlaan 200G-F, Heverlee, 3001, Belgium
| | - Akito Masuhara
- Yamagata University, department of Engineering, Yonezawa, Yamagata, 992-8510, Japan
| | - Eduard Fron
- KU Leuven, department of Chemistry, Celestijnenlaan 200G-F, Heverlee, 3001, Belgium
| | - Hideaki Mizuno
- KU Leuven, department of Chemistry, Celestijnenlaan 200G-F, Heverlee, 3001, Belgium
| | - Loredana Latterini
- University of Perugia, department of Chemistry, Biology and Biotechnology, via Elce di sotto 8, Perugia, Italy
| | - Susana Rocha
- KU Leuven, department of Chemistry, Celestijnenlaan 200G-F, Heverlee, 3001, Belgium.
| | - Hiroshi Uji-I
- KU Leuven, department of Chemistry, Celestijnenlaan 200G-F, Heverlee, 3001, Belgium.
- RIES Hokkaido University, Research Institute for Electronic Science, N20W10, Kita-Ward Sapporo, 0010020, Japan.
| |
Collapse
|
7
|
Lechner CC, Becker CFW. Silaffins in Silica Biomineralization and Biomimetic Silica Precipitation. Mar Drugs 2015; 13:5297-333. [PMID: 26295401 PMCID: PMC4557024 DOI: 10.3390/md13085297] [Citation(s) in RCA: 67] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2015] [Revised: 07/17/2015] [Accepted: 07/20/2015] [Indexed: 12/05/2022] Open
Abstract
Biomineralization processes leading to complex solid structures of inorganic material in biological systems are constantly gaining attention in biotechnology and biomedical research. An outstanding example for biomineral morphogenesis is the formation of highly elaborate, nano-patterned silica shells by diatoms. Among the organic macromolecules that have been closely linked to the tightly controlled precipitation of silica in diatoms, silaffins play an extraordinary role. These peptides typically occur as complex posttranslationally modified variants and are directly involved in the silica deposition process in diatoms. However, even in vitro silaffin-based peptides alone, with and without posttranslational modifications, can efficiently mediate biomimetic silica precipitation leading to silica material with different properties as well as with encapsulated cargo molecules of a large size range. In this review, the biomineralization process of silica in diatoms is summarized with a specific focus on silaffins and their in vitro silica precipitation properties. Applications in the area of bio- and nanotechnology as well as in diagnostics and therapy are discussed.
Collapse
Affiliation(s)
- Carolin C Lechner
- Swiss Federal Institute of Technology in Lausanne (EPFL), Fondation Sandoz Chair in Biophysical Chemistry of Macromolecules, 1015 Lausanne, Switzerland.
| | - Christian F W Becker
- Institute of Biological Chemistry, Department of Chemistry, University of Vienna, Währinger Straße 38, 1090 Vienna, Austria.
| |
Collapse
|
8
|
Contributions to reversed-phase column selectivity. J Chromatogr A 2015; 1395:57-64. [DOI: 10.1016/j.chroma.2015.03.044] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2014] [Revised: 03/17/2015] [Accepted: 03/18/2015] [Indexed: 11/23/2022]
|
9
|
Monolithic capillary columns based on silica and zirconium oxides for use in hydrophilic interaction liquid chromatography. Microchem J 2014. [DOI: 10.1016/j.microc.2014.05.012] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
|
10
|
Liu FK. Solid Phase Extraction of Neutral Analytes through Silica Gel Coated with Layers of Au Nanoparticles Self-Assembled with Alkanethiols. J CHIN CHEM SOC-TAIP 2013. [DOI: 10.1002/jccs.200800012] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
|
11
|
Perera S, Berthod A, Dodbiba E, Armstrong DW. Coupling solid-phase microextraction and laser desorption ionization for rapid identification of biological material. RAPID COMMUNICATIONS IN MASS SPECTROMETRY : RCM 2012; 26:853-62. [PMID: 22368066 DOI: 10.1002/rcm.6168] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/10/2023]
Abstract
RATIONALE Solid phase microextraction (SPME) use small fibers directly plunged in the solution under investigation to quickly extract and quantify by different techniques the amount of selected dissolved compounds. METHODS Biological materials, peptides or proteins are accurately identified by matrix-assisted laser desorption/ionization mass spectrometry (MALDI-MS). They are difficult to extract by SPME. This work looks for a chemical to be deposited onto fibers and able to act as a good SPME extractant as well as efficient matrix for MALDI detection. RESULTS 3-Hydroxy-2-naphthoic acid (HNA) and 2-hydroxy-1-(2-hydroxy-4-sulfo-1-naphthylazo)-3-naphthoic acid (HHSNNA) were compared to two classical matrices: α-cyano-4-hydroxycinnamic acid (CHCA) and 2,5-dihydrobenzoic acid (DHB). Bound to silica particles, DHB and HNA were found to be good MALDI matrices. Only the wide pore particles gave observable spectra. These particles were then attached in a thin layer onto wires to be used as fiber tips in SPME. Fibers loaded with peptides were introduced into the mass spectrometer to record fiber laser desorption ionization (FILDI) spectra. CONCLUSIONS SPME-FILDI experiments could quickly identify peptides and proteins in solutions. More work is needed to find the best matrix and the way to fix it onto the fiber.
Collapse
Affiliation(s)
- Sirantha Perera
- Chemistry and Biochemistry Department, University of Texas, Arlington, TX 76019, USA
| | | | | | | |
Collapse
|
12
|
Preparation and characterization of a poly(methyloctadecylsiloxane) thermally immobilized onto zirconized silica stationary phase for high-performance liquid chromatography. J Chromatogr A 2012; 1232:248-56. [DOI: 10.1016/j.chroma.2011.12.073] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2011] [Revised: 12/06/2011] [Accepted: 12/21/2011] [Indexed: 11/22/2022]
|
13
|
Porous ceramic/agarose composite adsorbents for fast protein liquid chromatography. J Chromatogr A 2012; 1223:126-30. [DOI: 10.1016/j.chroma.2011.12.050] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2011] [Revised: 12/12/2011] [Accepted: 12/15/2011] [Indexed: 11/20/2022]
|
14
|
Bi W, Zhou J, Row KH. Preparation and Application of Ionic Liquid-Modified Stationary Phases in High Performance Liquid Chromatography. SEP SCI TECHNOL 2012. [DOI: 10.1080/01496395.2011.608402] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/14/2022]
|
15
|
Bair MD, Dorsey JG. Effect of trimethylsilane pre-capping on monomeric C18 stationary phases made from high-purity type-B silica substrates: Efficiency, retention, and stability. J Chromatogr A 2012; 1220:35-43. [DOI: 10.1016/j.chroma.2011.11.041] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2011] [Revised: 11/17/2011] [Accepted: 11/18/2011] [Indexed: 11/27/2022]
|
16
|
Zhang Y, Luo H, Carr PW. Silica-based, hyper-crosslinked acid stable stationary phases for high performance liquid chromatography. J Chromatogr A 2011; 1228:110-24. [PMID: 21906745 DOI: 10.1016/j.chroma.2011.07.096] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2011] [Revised: 07/26/2011] [Accepted: 07/29/2011] [Indexed: 10/17/2022]
Abstract
A new family of hyper-crosslinked (HC) phases for use under very aggressive acid conditions including those encountered in ultra-fast, high temperature two-dimensional liquid chromatography (2DLC) has been recently introduced. This type of stationary phase shows significantly enhanced acid and thermal stability compared to the most acid stable, commercial RPLC phases. In addition, the use of "orthogonal" chemistry to make surface-confined polymer networks ensures good reproducibility and high efficiency. One of the most interesting features of the HC phases is the ability to derivatize the surface aromatic groups with various functional groups. This has led to the development of a family of hyper-crosslinked phases possessing a wide variety of chromatographic selectivities by attaching hydrophobic (e.g. -C₈), ionizable (e.g. -COOH, -SO₃H), aromatic (e.g. -toluene) or polar (e.g. -OH) species to the aromatic polymer network. HC reversed phases with various degrees of hydrophobicity and mixed-mode HC phases with added strong and weak cation exchange sites have been synthesized, characterized and applied. These silica-based acid-stable HC phases, with their attractive chromatographic properties, should be very useful in the separation of bases or biological analytes in acidic media, especially at elevated temperatures. This work reviews prior research on HC phases and introduces a novel HC phase made by alternative chemistry.
Collapse
Affiliation(s)
- Yu Zhang
- Department of Chemistry, University of Minnesota, 207 Pleasant St. S.E., Minneapolis, MN 55455, USA
| | | | | |
Collapse
|
17
|
Stastna M, Van Eyk J. Protein Separation: Liquid Chromatography. Clin Proteomics 2008. [DOI: 10.1002/9783527622153.ch3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
|
18
|
Zhao CF, Cann NM. Molecular Dynamics Study of Chiral Recognition for the Whelk-O1 Chiral Stationary Phase. Anal Chem 2008; 80:2426-38. [DOI: 10.1021/ac702126y] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- C. F. Zhao
- Department of Chemistry, Queen's University, Kingston, Ontario, Canada K7L 3N6
| | - N. M. Cann
- Department of Chemistry, Queen's University, Kingston, Ontario, Canada K7L 3N6
| |
Collapse
|
19
|
Luo H, Ma L, Zhang Y, Carr PW. Synthesis and characterization of silica-based hyper-crosslinked sulfonate-modified reversed stationary phases. J Chromatogr A 2008; 1182:41-55. [PMID: 18207150 PMCID: PMC3217304 DOI: 10.1016/j.chroma.2007.11.104] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2007] [Revised: 11/21/2007] [Accepted: 11/30/2007] [Indexed: 11/26/2022]
Abstract
A novel type of silica-based sulfonate-modified reversed phase ((-)SO3-HC-C8) has been synthesized; it is based on a newly developed acid stable "hyper-crosslinked" C8 derivatized reversed phase, denoted HC-C8. The (-)SO3-HC-C8 phases containing controlled amounts of sulfonyl groups were made by sulfonating the aromatic hyper-crosslinked network of the HC-C(8) phase at different temperatures. The (-)SO3-HC-C8 phases are only slightly less hydrophobic than the parent HC-C8 phase. The added sulfonyl groups provide a unique strong cation-exchange selectivity to the hydrophobic hyper-crosslinked substrate as indicated by the very large C coefficient as shown through Snyder's hydrophobic subtraction reversed-phase characterization method. This cation-exchange activity clearly distinguishes the sulfonated phase from all other reversed phases as confirmed by the very high values of Snyder's column comparison function F(s). In addition, as was found in previous studies of silica-based and zirconia-based reversed phases, a strong correlation between the cation-exchange interaction and hydrophobic interaction was observed for these sulfonated phases in studies of the retention of cationic solutes. The overall chromatographic selectivity of these (-)SO3-HC-C8 phases is greatly enhanced by its high hydrophobicity through a "hydrophobically assisted" ion-exchange retention process.
Collapse
Affiliation(s)
| | | | - Yu Zhang
- Department of Chemistry, University of Minnesota, Smith and Kolthoff Hall, 207 Pleasant Street SE, Minneapolis, MN 55455, USA
| | - Peter W. Carr
- Department of Chemistry, University of Minnesota, Smith and Kolthoff Hall, 207 Pleasant Street SE, Minneapolis, MN 55455, USA
| |
Collapse
|
20
|
Silica-based, acid-stable stationary phases for high performance liquid chromatography. Anal Bioanal Chem 2008; 391:919-23. [DOI: 10.1007/s00216-008-1900-8] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
|
21
|
Affiliation(s)
- Shulamit Levin
- a Analytical Department , Medtechnica Inc. , Efal St. 5 Kiriat Arye, Petach Tikva , Israel , 49002
| |
Collapse
|
22
|
McNeff CV, Yan B, Stoll DR, Henry RA. Practice and theory of high temperature liquid chromatography. J Sep Sci 2007; 30:1672-85. [PMID: 17623448 DOI: 10.1002/jssc.200600526] [Citation(s) in RCA: 101] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
High temperature liquid chromatography (HTLC) exists in a temperature region beyond ambient (ca. 40 degrees C) and below super critical temperatures. The promises of HTLC, such as increased analysis speed, enhanced separation productivity, "green" LC with pure water mobile phases coupled to universal FID detection, and fast analysis of complex samples by combination with fast 2-D techniques, have become an option for routine practice. The focus of this paper is to review the key developments that have made the application of HTLC a practical technique and draw attention to new developments in 2-D techniques that incorporate HTLC that offer an opportunity to vastly increase the usefulness of HPLC for the analysis of complex samples.
Collapse
|
23
|
Pesek JJ, Matyska MT, Hearn MTW, Boysen R. Temperature effects on solute retention for hydride-based stationary phases. J Sep Sci 2007; 30:1150-7. [PMID: 17595950 DOI: 10.1002/jssc.200700005] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
The effect of solute retention is investigated for two hydride-based stationary phases: bidentate C18 and cholesterol. Several small molecules and peptides are used as solutes. In the reversed-phase mode, most compounds have the expected temperature behavior, i.e. decreasing retention with increasing temperature. Two analogs of the drug lisinopril do exhibit the opposite behavior on the cholesterol column; increasing retention with increasing temperature. In the aqueous normal phase (ANP) mode, more compounds, particularly certain peptides, have this unusual retention behavior with respect to temperature. These preliminary studies indicate that as ANP retention becomes stronger, there is a greater possibility of observing increasing retention with increasing temperature.
Collapse
Affiliation(s)
- Joseph J Pesek
- Department of Chemistry, San Jose State University, San Jose, CA 95112, USA.
| | | | | | | |
Collapse
|
24
|
Polyakova Y, Ho Row K. HPLC of Some Polar Compounds on a Porous Graphitized Carbon HypercarbTM Column. J LIQ CHROMATOGR R T 2007. [DOI: 10.1080/10826070500330687] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Affiliation(s)
- Yulia Polyakova
- a Center for Advanced Bioseparation Technology and Dept. of Chem. Eng. , Inha University , Incheon, South Korea
| | - Kyung Ho Row
- a Center for Advanced Bioseparation Technology and Dept. of Chem. Eng. , Inha University , Incheon, South Korea
| |
Collapse
|
25
|
Affiliation(s)
- Akira SANO
- Analytical Chemistry, Faculty of Pharmaceutical Sciences, Tokyo University of Science
| | - Hiroshi NAKAMURA
- Analytical Chemistry, Faculty of Pharmaceutical Sciences, Tokyo University of Science
| |
Collapse
|
26
|
Bogusz M, Hill DW, Rehorek A. Comparability of RP-HPLC Retention Indices of Drugs in Three Databases. J LIQ CHROMATOGR R T 2006. [DOI: 10.1080/10826079608006319] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Affiliation(s)
- Maciej Bogusz
- a Institute of Forensic Medicine , Aachen University of Technology , 52057, Aachen, Germany
| | - Dennis W. Hill
- b Microchemistry Laboratory , University of Connecticut , Storrs, CT, 06269, USA
| | - Astrid Rehorek
- c E. Merck, Chromatography Division , 64271, Darmstadt, Germany
| |
Collapse
|
27
|
Balcan M, Cserháti T, Forgács E. Influence Of Organic Modifiers On The Retention Characteristics Of Graphitized Carbon Column. ANAL LETT 2006. [DOI: 10.1080/00032719708006431] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
|
28
|
Zaharescu M, Cserháti T, Forgács E. Retention Characteristics of Titanium Dioxide and Polyethylene-Coated Titanium Dioxide as Reversed-Phase Supports. J LIQ CHROMATOGR R T 2006. [DOI: 10.1080/10826079708006575] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Affiliation(s)
- M. Zaharescu
- a Institute of Physical Chemistry “I.G.Murgulescu” Romanian Academy , Bucharest, Romania
| | - T. Cserháti
- b Central Research Institute for Chemistry Hungarian Academy of Sciences , P.O.Box 17 1525, Budapest, Hungary
| | - E. Forgács
- b Central Research Institute for Chemistry Hungarian Academy of Sciences , P.O.Box 17 1525, Budapest, Hungary
| |
Collapse
|
29
|
Pinto GMF, Collins KE, Sales IC, Jardim F. C-18 STATIONARY PHASES SORBED ON ZIRCONIZED SILICA FOR USE IN HPLC. J LIQ CHROMATOGR R T 2006. [DOI: 10.1081/jlc-100108740] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Affiliation(s)
- Glaucia Maria Ferreira Pinto
- a Department of Analytical Chemistry , Chemistry Institute , UNICAMP, Cx. Postal 6154, Campinas, S. P., 13083-970, Brazil
| | - Kenneth E. Collins
- a Department of Analytical Chemistry , Chemistry Institute , UNICAMP, Cx. Postal 6154, Campinas, S. P., 13083-970, Brazil
| | - Isabel Cristina Sales
- a Department of Analytical Chemistry , Chemistry Institute , UNICAMP, Cx. Postal 6154, Campinas, S. P., 13083-970, Brazil
| | - Fontes Jardim
- b Department of Analytical Chemistry , Chemistry Institute , UNICAMP, Cx. Postal 6154, Campinas, S. P., 13083-970, Brazil
| |
Collapse
|
30
|
Jandera P, Novotná K. Characterization of High‐Pressure Liquid Chromatography Columns using Chromatographic Methods. ANAL LETT 2006. [DOI: 10.1080/00032710600773424] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
|
31
|
Srinivasan G, Sander LC, Müller K. Effect of surface coverage on the conformation and mobility of C18-modified silica gels. Anal Bioanal Chem 2005; 384:514-24. [PMID: 16315015 DOI: 10.1007/s00216-005-0161-z] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2005] [Revised: 09/29/2005] [Accepted: 09/29/2005] [Indexed: 11/26/2022]
Abstract
C18-modified silica gels with surface coverages of 2 to 8.2 micromol m(-2), were prepared by different synthetic pathways and characterized by Fourier Transform infrared spectroscopy (FTIR), solid-state nuclear magnetic resonance (NMR) spectroscopy, and chromatographic measurements. The effects of temperature and bonding density on the conformational order of C18-modified silica gels were studied in detail by FTIR spectroscopy. The silane functionality and degree of cross-linking of silane ligands on the silica surface were evaluated by 29Si cross-polarization magic-angle spinning (CP/MAS) NMR and the structural order and mobility of the alkyl chains were investigated by 13C CP/MAS NMR spectroscopy. CH2 symmetric and anti-symmetric stretching bands and CH2 wagging bands were used as IR probes to monitor the conformational order and flexibility of the alkyl chains in the C18 phases. Qualitative information about the conformational order was obtained from frequency shifts of the CH2 symmetric and anti-symmetric stretching bands. The relative amounts of kink/gauche-trans-gauche, double-gauche, and end-gauche conformers in the alkyl chains were determined by analysis of CH2 wagging bands. These results indicate that surface coverage plays a dominant role in the conformational order of C18-modified silica gels. The FTIR and NMR data are discussed in the context of the chromatographic shape-selectivity differences.
Collapse
Affiliation(s)
- Gokulakrishnan Srinivasan
- Institut für Physikalische Chemie, Universität Stuttgart, Pfaffenwaldring 55, 70569, Stuttgart, Germany
| | | | | |
Collapse
|
32
|
Yang X, Ma L, Carr PW. High temperature fast chromatography of proteins using a silica-based stationary phase with greatly enhanced low pH stability. J Chromatogr A 2005; 1079:213-20. [PMID: 16038307 DOI: 10.1016/j.chroma.2004.11.069] [Citation(s) in RCA: 63] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Reversed-phase liquid chromatography (RPLC) is very widely used for the separation and characterization of proteins and peptides. A novel type of highly stable silica-based stationary phase has been developed for protein separations. A dense monolayer of dimethyl-(chloromethyl)phenylethyl)-chlorosilane (DM-CMPES) on the surface of silica is "hyper-crosslinked" with a polyfunctional aromatic crosslinker through Friedel-Crafts chemistry resulting in stationary phases with extraordinary stability in acidic media. Elemental analysis data confirm the high degree of cross-linking among the surface groups. The hyper-crosslinked phases are extremely stable under highly acidic mobile phase conditions even at a temperature as high as 150 degrees C. A wide-pore (300 A) material made in this way is used here to separate proteins by a reversed-phase mechanism and compared to a commercially available "sterically protected" C18 phase. For small molecules, including neutral and basic compounds, these crosslinked phases give comparable peak shape and efficiency to the commercial phase. Our results show that no pore blockage takes place as commonly afflicts polymer coated phases. In consequence, protein separations on the new phases are acceptable. Using strong ion-pairing reagents, such as HPF6, improves the separation efficiency. Compared to the commercial phases, these new phases can be used at lower pHs and much higher temperatures thereby enabling much faster separations which is the primary focus of this work. Better efficiency for proteins was obtained at high temperature. However, at conventional linear velocities the instability of proteins at high temperature becomes a problem which establishes an upper temperature limit. Uses of a narrowbore column and high flow rates both solves this problem by reducing the time that proteins spend on the hot column and, of course, speeds up the separation of the protein mixture. Finally, an ultrafast gradient (<1 min) protein separation was obtained by utilizing the high temperature and thus high linear velocities afforded by the extreme stability of these new phases. The phases are stable even after 50h of exposure to 0.1% TFA at 120 degrees C. This paper is dedicated to the memory of Csaba Horvath whose work in high temperature HPLC inspired the development of the stationary phases described here.
Collapse
Affiliation(s)
- Xiqin Yang
- Department of Chemistry, University of Minnesota, Smith and Kolthoff Hall, 207 Pleasant Street SE, Minneapolis, MN 55455, USA
| | | | | |
Collapse
|
33
|
Morais LSR, Jardim ICSF. Characterization of a new stationary phase based on microwave immobilized polybutadiene on titanium oxide-modified silica. J Chromatogr A 2005; 1073:127-35. [PMID: 15909514 DOI: 10.1016/j.chroma.2004.09.044] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Titanium oxide-modified silica was prepared by reaction of silica with titanium tetrabutoxide and then was used as support in the preparation of stationary phases with self-immobilized polybutadiene (PBD) and PBD immobilized through microwave radiation. Chromatographic performance of the stationary phases was evaluated in terms of the efficiency (plates/m), asymmetry (A(s)), retention factor (k) and resolution (R(s)) of two standard sample mixtures, one of then containing the basic compound N,N-dimethylaniline. A microwave irradiation of 30 min at 520 W gave the best efficiency (86,500 N m(-1)), greater than that of a 6-day self immobilized phase (69,500 N m(-1)). Self-immobilized stationary phases prepared with bare silica were also studied for comparison. These resulted in lower chromatographic performance, 43,800 N m(-1), when compared to the self-immobilized phase prepared with titanized silica.
Collapse
Affiliation(s)
- Lais S R Morais
- Laboratório de Pesquisas em Cromatografia Líquida-LABCROM, Instituto de Química, Universidade Estadual de Campinas, Caixa Postal 6154, CEP 13084-971 Campinas, SP, Brazil
| | | |
Collapse
|
34
|
Tonhi E, Collins KE, Collins CH. High-performance liquid chromatographic stationary phases based on poly(dimethylsiloxane) immobilized on silica. J Chromatogr A 2005; 1075:87-94. [PMID: 15974121 DOI: 10.1016/j.chroma.2005.03.110] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
This work describes the preparation and characterization of six stationary phases for high-performance liquid chromatography (HPLC) obtained by deposition of poly(dimethylsiloxane) (PDMS) in HPLC silica particles, followed by immobilization using different processes (thermal treatments, thermal treatment + microwave irradiation, self-immobilization + gamma irradiation and self-immobilization + microwave irradiation). The chromatographic parameters of all the phases were evaluated with a mixture of test compounds having varied natures (acid, basic and neutral). The stability of one of these phases was evaluated in both a neutral mobile phase and a higher pH mobile phase used at an elevated temperature, with promising results.
Collapse
Affiliation(s)
- Edivan Tonhi
- Instituto de Química, Universidade Estadual de Campinas, Caixa Postal 6154, CEP 13084-971, Campinas, SP, Brazil
| | | | | |
Collapse
|
35
|
Trammell BC, Boissel CA, Carignan C, O'Shea DJ, Hudalla CJ, Neue UD, Iraneta PC. Development of an accelerated low-pH reversed-phase liquid chromatography column stability test. J Chromatogr A 2004; 1060:153-63. [PMID: 15628158 DOI: 10.1016/j.chroma.2004.04.016] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The important experimental design criteria for an accelerated low-pH RPLC column stability test are discussed. The influence of method variables on the amount and rate of retention-loss and the final optimized parameters for the accelerated low-pH RPLC stability test are presented. The retention-loss curves for selected C8 and C18 stationary phases are compared. These studies indicate that ligand chain length, functionality and bonding density play an important role in determining the low-pH stability of a stationary phase. Additionally, elemental analysis data are used to infer the mechanism responsible for the observed retention-loss under low-pH conditions.
Collapse
|
36
|
Jardim ICS, Collins KE, Collins CH. Immobilized polysiloxanes as stationary phases for high-performance liquid chromatography and solid phase extraction. Microchem J 2004. [DOI: 10.1016/j.microc.2004.02.013] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
|
37
|
Nawrocki J, Dunlap C, McCormick A, Carr PW. Part I. Chromatography using ultra-stable metal oxide-based stationary phases for HPLC. J Chromatogr A 2004; 1028:1-30. [PMID: 14969280 DOI: 10.1016/j.chroma.2003.11.052] [Citation(s) in RCA: 228] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
The first part of the review contrasts the main drawbacks of silica-based packings such as their relative thermal and chemical instability with excellent stability of metal oxides. The paper concerns mainly ZrO2, TiO2 and Al2O3. Methods of preparation of spherical particles for HPLC are described. Surface chemistry of the oxides is, however, very different from that of silica. Ability of the oxides to ion- and ligand exchange is discussed from a chromatographic point of view.
Collapse
Affiliation(s)
- J Nawrocki
- Department of Water Treatment Technology, Faculty of Chemistry, A. Mickiewicz University, Drzymały 24, 60-613 Poznañ, Poland.
| | | | | | | |
Collapse
|
38
|
Sunseri JD, Cooper WT, Dorsey JG. Reducing residual silanol interactions in reversed-phase liquid chromatography. J Chromatogr A 2003; 1011:23-9. [PMID: 14518759 DOI: 10.1016/s0021-9673(03)01070-7] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
This study describes the thermal pretreatment of a silica gel between 150 and 800 degrees C before derivatization with dimethyloctadecylchlorosilane as a means of reducing residual silanol activity in HPLC bonded stationary phases. A time study was done from 12 to 48 h to find the optimum time needed for dehydroxylation. With increasing pretreatment temperatures, the number of reactive silanols is reduced from 8 micromol/m2 to essentially zero at 1000 degrees C (where sintering occurs). The effects of the thermal pretreatments were observed with diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) and solid state cross polarization magic angle spinning (CP-MAS) 29Si NMR. Following derivatization, residual silanol activity and pH stability were tested by packing columns with the derivatized silica and carrying out a series of reversed-phase liquid chromatography (RPLC) experiments. Residual silanol activity was greatly reduced when the silica was pretreated at 800 degrees C, leading to less peak tailing for basic solutes. In a strongly basic mobile phase (pH 11.5) the pretreated silica was surprisingly stable, although bond cleavage of C18 groups from the surface was observed.
Collapse
Affiliation(s)
- J David Sunseri
- The Florida State University, Department of Chemistry and Biochemistry, Tallahassee, FL 32306-4390, USA
| | | | | |
Collapse
|
39
|
Rimmer CA, Sander LC, Wise SA, Dorsey JG. Synthesis and characterization of C13 to C18 stationary phases by monomeric, solution polymerized, and surface polymerized approaches. J Chromatogr A 2003; 1007:11-20. [PMID: 12924546 DOI: 10.1016/s0021-9673(03)00959-2] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
A series of bonded phases were synthesized from consecutive length alkylsilanes ranging from C13 through C18, with three different bonding chemistries (monomeric, solution polymerized, and surface polymerized) at each phase length. The phases were characterized in terms of methylene selectivity, shape selectivity, and band broadening. No significant chromatographic differences were found to result from the synthetic routes, except that the different bonding chemistries provide a different range of bonding densities. For bonding densities ranging from 2 to 8 micromol/m2, a linear increase in methylene selectivity was observed with increasing bonding density. Over the narrow range of bonded phase lengths investigated, shape selectivity is more dependent on density than phase length.
Collapse
Affiliation(s)
- Catherine A Rimmer
- Chemical Science and Technology Laboratory, Analytical Chemistry Division, National Institute of Standards and Technology, 100 Bureau Drive. Stop 8392, Gaithersburg, MD 20899-8392, USA.
| | | | | | | |
Collapse
|
40
|
Taillardat-Bertschinger A, Carrupt PA, Barbato F, Testa B. Immobilized artificial membrane HPLC in drug research. J Med Chem 2003; 46:655-65. [PMID: 12593643 DOI: 10.1021/jm020265j] [Citation(s) in RCA: 116] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
|
41
|
Trammell BC, Ma L, Luo H, Jin D, Hillmyer MA, Carr PW. Highly cross-linked self-assembled monolayer stationary phases: an approach to greatly enhancing the low pH stability of silica-based stationary phases. Anal Chem 2002; 74:4634-9. [PMID: 12349964 DOI: 10.1021/ac020206d] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
A new type of silica-based stationary phase with dramatically improved acid stability compared to any currently available silica-based stationary phase has been developed. Superior low pH stability is achieved by first self-assembling a densely bonded monolayer of (chloromethyl)-phenylethyltrichlorosilane (CMPES). The self-assembly step is followed by a Friedel-Crafts cross-linking of the reactive moieties with their neighbors, by addition of secondary, cross-linkable aromatic reagents, or by both. This phase is not endcapped. Elemental analysis data shows that an aluminum chloride catalyst is very effective at bonding aromatic cross-linking reagents, such as styrene heptamer and triphenylmethane, to the reactive CMPES monolayer. The stability of the retention factor of decylbenzene on the cross-linked self-assembled CMPES phases is compared to a sterically protected C18 phase to illustrate its superior resistance to acid-catalyzed-phase loss. Inverse size exclusion chromatography and flow-curve comparisons of the cross-linked self-assembled CMPES and the sterically protected C18 stationary phases illustrate their similar chromatographic efficiency.
Collapse
Affiliation(s)
- Brian C Trammell
- Department of Chemistry, University of Minnesota, Minneapolis 55455, USA
| | | | | | | | | | | |
Collapse
|
42
|
Liem LK, Choong LHL, Woo KT. Porous graphitic carbon shows promise for the rapid screening partial DPD deficiency in lymphocyte dihydropyrimidine dehydrogenase in Chinese, Indian and Malay in Singapore by using semi-automated HPLC-radioassay. Clin Biochem 2002; 35:181-7. [PMID: 12074825 DOI: 10.1016/s0009-9120(02)00303-x] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
OBJECTIVE Dihydropyrimidine dehydrogenase (DPD) catalyzes the degradation of thymine, uracil, and the chemotherapeutic drug 5-Fluorouracil. In general reverse-phase high pressure liquid chromatography is the standard method for separating 5-[2-(14)C]Fluorouracil and 5-[2-(14)C]Fluoro-5,6-dihydrouracil. However, the use of 100% aqueous solution (as HPLC mobile phase) may collapse the C-18 bonded phase and result in a retention time shift. The aim of this study is to develop a rapid, reproducible, sensitive method for screening partial DPD deficiency in healthy volunteers. DESIGN AND METHODS The activity of DPD was measured using 5-[2- (14)C]Fluorouracil (5-[2-(14)C]FUra) followed by separation of substrate and product 5-[2-(14)C]FUraH(2) with a 15 x 4.6 mm I.D., 5 microm particle size (d(p)) porous graphitic carbon (PGC) column (Hypercarb(R)) and HPLC with online detection of the radioactivity. This was standardized using the protein concentration of the cytosol (NanoOrange(R) Protein Quantitation). RESULTS Complete baseline separation of 5-[2-(14)C]Fluorouracil (5-[2-(14)C]FUra) and 5-[2-(14)C]Fluoro-5,6-dihydrouracil (5-[2-(14)C]FUraH(2)) was achieved using a porous graphitic carbon (PGC) column. The detection limit for 5-[2-(14)C]FUraH(2) was 0.4 pmol. CONCLUSIONS By using linear gradient separation (0.1% Trifluoroacetic acid [TFA] in water to 100% Methanol) protocols in concert with PGC columns (Hypercarb(R)), we have demonstrated that a PGC column has a distinct advantage over C-18 reverse phase columns in terms of column stability (pH 1-14). This method provides an improvement on the specific assay for DPD enzyme activity. It is rapid, reproducible and sensitive and can be used for routine screening for healthy and cancer patients for partial and profound DPD deficiency before treatment with 5- FUra.
Collapse
Affiliation(s)
- Lie Kuo Liem
- Donner Laboratory, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA.
| | | | | |
Collapse
|
43
|
Donovan SF, Pescatore MC. Method for measuring the logarithm of the octanol-water partition coefficient by using short octadecyl-poly(vinyl alcohol) high-performance liquid chromatography columns. J Chromatogr A 2002; 952:47-61. [PMID: 12064545 DOI: 10.1016/s0021-9673(02)00064-x] [Citation(s) in RCA: 119] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
A simple, quick, versatile and inexpensive HPLC method to estimate the logarithm of the octanol-water partition coefficient (log Pow) employing a methanol-water gradient and a short octadecyl-poly(vinyl alcohol) (ODP) column is described. This method is different from published HPLC-based log Pow methods because it uses retention times from a rapid methanol-water gradient to directly generate log Pow estimates, rather than from a series of isocratic mixtures extrapolated to 100% water. These HPLC log Pow values have good precision and correlate well with traditional shake-flask log Pow values. If necessary, the log Pow determination (including replications) can easily be carried out using only a milligram of sample. By suppressing ionization of acids and bases by the use of a buffer in the aqueous phase, the method can measure the log Pow of neutral organic molecules at any pH between 2 and 13. The method can be used with impure material and is rapid, 7 min per run and 4 min equilibration; it lends itself to and has been utilized for high-throughput hydrophobicity determinations (we have now carried out thousands of HPLC log Pow measurements by this method).
Collapse
|
44
|
Tonhi E, Bachmann S, Albert K, Jardim ICSF, Collins KE, Collins CH. High-performance liquid chromatographic stationary phases based on poly(methyloctylsiloxane) immobilized on silica. I. Physical and chemical characterizations. J Chromatogr A 2002; 948:97-107. [PMID: 12831187 DOI: 10.1016/s0021-9673(01)01612-0] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Five different reversed-phase materials for high-performance liquid chromatography were obtained by deposition of poly(methyloctylsiloxane) in HPLC silica particles, followed by immobilization using different processes: thermal treatment (120 or 220 degrees C for 4 h), irradiation with microwaves (495 W for 15 min), gamma radiation (dose of 80 kGy) and self-immobilization. These phases were characterized by gel permeation chromatography, percent carbon, 13C and 29Si solid-state nuclear magnetic resonance spectroscopy, infrared spectroscopy, thermogravimetric analysis and scanning electron microscopy. The results show that the different immobilization processes produce different physical characteristics in the prepared phases.
Collapse
Affiliation(s)
- Edivan Tonhi
- Instituto de Química, Universidade Estadual de Campinas, Caixa Postal 6154, 13083-970 Campinas, SP, Brazil
| | | | | | | | | | | |
Collapse
|
45
|
Tonhi E, Collins KE, Collins CH. High-performance liquid chromatographic stationary phases based on poly(methyloctylsiloxane) immobilized on silica. II. Chromatographic evaluation. J Chromatogr A 2002; 948:109-19. [PMID: 12831188 DOI: 10.1016/s0021-9673(02)00006-7] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
This work describes the chromatographic characterization of stationary phases prepared by deposition of poly(methyloctylsiloxane) (PMOS) on silica followed by immobilization using one of several different processes: thermal treatments (120 or 220 degrees C for 4 h), microwave irradiation (495 W for 15 min), gamma radiation (dose of 80 kGy) or self-immobilization. This evaluation was based on the chromatographic parameters of several test solutes. The stationary phases immobilized at 220 degrees C and which underwent self-immobilization were not appropriate for chromatographic use but the other immobilized phases presented chromatographic performances similar in most respects to a commercial phase (Rainin C8) while the peak characteristics of the basic probe were significantly better with these phases.
Collapse
Affiliation(s)
- Edivan Tonhi
- Instituto de Química, Universidade Estadual de Campinas, Caixa Postal 6154, CEP 13083-970 Campinas, SP, Brazil
| | | | | |
Collapse
|
46
|
Forgács E, Cserháti T. Quantitative relationship between the retention of peptides on a reversed-phase alumina support and their physicochemical parameters. J Chromatogr A 2002; 948:69-75. [PMID: 12831184 DOI: 10.1016/s0021-9673(01)01261-4] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
The retention time of 16 peptides was determined on polyethylene-coated alumina stationary phase using mixtures of acetonitrile (MeCN) and acidic and basic phosphate buffers as mobile phases. The majority of peptides showed nonlinear retention behaviour, their retention decreased with increasing concentration of MeCN in the lower concentration range, reached a minimum and increased again with increasing concentration of MeCN in the higher concentration range. Quadratic equations described well the atypical retention behaviour of peptides, the significance level being always over 95%. Principal component analysis indicated that the steric parameters of peptides exerted the highest influence on their retention on polyethylene-coated alumina stationary phase.
Collapse
Affiliation(s)
- Esther Forgács
- Institute of Chemistry, Chemical Research Centre, Hungarian Academy of Sciences, P.O. Box 17, H-1525 Budapest, Hungary.
| | | |
Collapse
|
47
|
Chapter 1 Fundamentals of countercurrent chromatography. ACTA ACUST UNITED AC 2002. [DOI: 10.1016/s0166-526x(02)80004-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register]
|
48
|
Zhuravlev ND, Siepmann JI, Schure MR. Surface coverages of bonded-phase ligands on silica: a computational study. Anal Chem 2001; 73:4006-11. [PMID: 11534729 DOI: 10.1021/ac010298r] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
A computational study of the packing of various bonded-phase ligands bound to chromatographic silica is presented. This is done with the intention of examing the type of surface structures that are typically found in real chromatographic systems. Utilizing the surface structure of the (111) face of the beta-cristobalite crystal, it is shown that the maximum surface coverages of dimethyloctylsilane, dimethyloctadecylsilane, triisopropylsilane, diisopropyloctylsilane, and diisopropyloctadecylsilane can be calculated that are in good agreement with experiment. The maximum surface coverages are also calculated for the (100) face of the beta-cristobalite crystal and for a set of random silica surfaces. The coverages for the latter two surfaces types are found to be significantly lower than the experimental values for chromatographic silica surfaces. These results further suggest that chromatographic silica surfaces may resemble crystalline surface sites similar to the (111) face of beta-cristobalite, as has been previously suggested in the literature. Hence, these structures can be reliably utilized in molecular simulations of bonded-phase chromatography where the atomic-level detail of the silica surface has been previously lacking.
Collapse
Affiliation(s)
- N D Zhuravlev
- Department of Chemistry, University of Minnesota, Minneapolis 55455-0431, USA.
| | | | | |
Collapse
|
49
|
McKeown AP, Euerby MR, Johnson CM, Koeberle M, Lomax H, Ritchie H, Ross P. An evaluation of unbonded silica stationary phases for the separation of basic analytes using capillary electrochromatography. Chromatographia 2000. [DOI: 10.1007/bf02491004] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
|
50
|
Gawdzik B, Osypiuk J. Reversed-phase high-performance liquid chromatography on porous copolymers of different chemical structure. J Chromatogr A 2000; 898:13-21. [PMID: 11185619 DOI: 10.1016/s0021-9673(00)00787-1] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
The influence of chemical structure of porous polymers on the chromatographic properties of high-performance liquid chromatography columns was studied. Columns were packed with four different porous copolymers: di(methacryloyloxymethyl)naphthalene-divinylbenzene containing ester functional groups, 4,4'-bis(maleimido)diphenylmethane-divinylbenzene with imide groups, di(4,4'-dimethacrylphenyl)sulfone-divinylbenzene which contains sulphonyl groups, and styrenedivinylbenzene with any functional groups. Using the alkyl aryl ketone scale, the retention indices of five homologous series (alkylbenzenes, alkyl aryl ketones, N-alkylanilines, alkyl aryl ethers, alkylbenzoates) and column test compounds (toluene, nitrobenzene, p-cresol, 2-phenylethanol, N-methylaniline) were calculated. Their values were used for comparison of the selectivities of the studied polymeric packings.
Collapse
Affiliation(s)
- B Gawdzik
- Faculty of Chemistry, MCS University, Lublin, Poland
| | | |
Collapse
|