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Quantitative Explanation of Basic Compound Retention Mechanisms in Reversed-Phase Mode Liquid Chromatography. SEPARATIONS 2020. [DOI: 10.3390/separations7040061] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
The quantitative analysis of the chromatographic behavior of basic compounds measured with pentyl-, hexenyl-, and octyl-bonded silica gels were analyzed in silico employing model phases. The main retention force was the van der Waals (VW) interaction, and the main desorption force was an electrostatic (ES) interaction. The contribution of hydrogen bonding (HB) was weak compared to that for acidic compounds. The quantitative explanation was achieved utilizing the calculated VW, HB, and ES energy values obtained from a molecular mechanics program. The electron localization was observed at the molecular interaction-site calculated MOPAC program. This fundamental approach was like that of explaining chemical reactions. The difference was electron localization in chromatography or electron transfer in a chemical reaction.
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Abstract
The high performance of chemically-modified silica gel packing materials is based on the utilization of pure silica gels. Earlier silica gels used to be made from inorganic silica; however, nowadays, silica gels are made from organic silanes. The surface smoothness and lack of trace metals of new silica gels permits easy surface modifications (chemical reactions) and improves the reproducibility and stability. Sharpening peak symmetry is based on developing better surface modification methods (silylation). Typical examples can be found in the chromatography of amitriptyline for silanol testing and that of quinizarin for trace metal testing. These test compounds were selected and demonstrated sensitive results in the measurement of trace amounts of either silanol or trace metals. Here, we demonstrate the three-dimensional model chemical structures of bonded-phase silica gels with surface electron density for easy understanding of the molecular interaction sites with analytes. Furthermore, a quantitative explanation of hydrophilic and hydrophobic liquid chromatographies was provided. The synthesis methods of superficially porous silica gels and their modified products were introduced.
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Kalanur SS, Seetharamappa J. Electrochemical Oxidation of Bioactive Carbamazepine and Its Interaction with DNA. ANAL LETT 2010. [DOI: 10.1080/00032710903406870] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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Vuckovic D, Cudjoe E, Hein D, Pawliszyn J. Automation of Solid-Phase Microextraction in High-Throughput Format and Applications to Drug Analysis. Anal Chem 2008; 80:6870-80. [DOI: 10.1021/ac800936r] [Citation(s) in RCA: 109] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Dajana Vuckovic
- Department of Chemistry, University of Waterloo, Waterloo, Ontario, Canada, and PAS Technology, Magdala, Germany
| | - Erasmus Cudjoe
- Department of Chemistry, University of Waterloo, Waterloo, Ontario, Canada, and PAS Technology, Magdala, Germany
| | - Dietmar Hein
- Department of Chemistry, University of Waterloo, Waterloo, Ontario, Canada, and PAS Technology, Magdala, Germany
| | - Janusz Pawliszyn
- Department of Chemistry, University of Waterloo, Waterloo, Ontario, Canada, and PAS Technology, Magdala, Germany
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Tazerouti F, Badjah‐Hadj‐Ahmed AY, Hanai T. Analysis of the Mechanism of Retention on a Modified β‐Cyclodextrin/Silica Chiral Stationary Phase using a Computational Chemical Method. J LIQ CHROMATOGR R T 2007. [DOI: 10.1080/10826070701632345] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Affiliation(s)
- Fairouz Tazerouti
- a Laboratoire d'Analyse Organique Fonctionnelle, U.S.T.H.B., Faculté de Chimie , Alger, Algeria
| | | | - Toshihiko Hanai
- b Health Research Foundation, Institut Pasteur , Kyoto, Japan
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Hanai T, Homma H. Chromatography In Silico: Retention of Acidic Drugs on a Guanidino Ion‐Exchanger. J LIQ CHROMATOGR R T 2007. [DOI: 10.1080/10826070701360277] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Affiliation(s)
- Toshihiko Hanai
- a Health Research Foundation, Institut Pasteur , Kyoto, Japan
| | - Hiroshi Homma
- b School of Pharmaceutical Sciences, Kitasato University , Tokyo, Japan
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Hanai T, Masuda Y, Homma H. Chromatography In Silico; Retention of Basic Compounds on a Carboxyl Ion Exchanger. J LIQ CHROMATOGR R T 2006. [DOI: 10.1080/10826070500295187] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Affiliation(s)
- Toshihiko Hanai
- a Health Research Foundation , Institut Pasteur , Kyoto, Japan
| | - Yuiko Masuda
- b School of Pharmaceutical Sciences , Kitasato University , Tokyo, Japan
| | - Hiroshi Homma
- b School of Pharmaceutical Sciences , Kitasato University , Tokyo, Japan
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