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Dembek M, Bacskay I, Buratti A, Catani M, Felinger A, Buszewski B, Bocian S. Retention mechanism on phosphodiester stationary phases in hydrophilic interaction liquid chromatography and purely aqueous mobile phase part II: Overloading with limited soluble samples. J Chromatogr A 2024; 1715:464596. [PMID: 38159406 DOI: 10.1016/j.chroma.2023.464596] [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: 08/31/2023] [Revised: 12/13/2023] [Accepted: 12/19/2023] [Indexed: 01/03/2024]
Abstract
The adsorption behaviour of caffeine and theophylline under hydrophilic interaction chromatography and purely aqueous conditions was investigated on four phosphodiester stationary phases. Solute adsorption isotherms were determined by frontal analysis or inverse method. The bi-Langmuir model was found to be the best choice to describe the behaviour of caffeine and theophylline adsorption in purely aqueous conditions, whereas the bi-Moreau model describes the adsorption phenomena in HILIC conditions. The results obtained demonstrate that the interaction of caffeine and theophylline with the stationary phase surface varies depending on the mobile phase composition. Both in pure aqueous mobile phase and in HILIC mode, the heterogeneity of the surface of the studied stationary phases is confirmed. In hydrophilic solutions, the sample molecules interact with the stationary phase only. In hydrophobic conditions, a lateral interaction occurs between caffeine or theophylline molecules, which are poorly soluble in acetonitrile-rich solvents. This confirms that the same compound on the same stationary phase can behave rather differently, depending on the mobile phase composition. Thus, the mobile phase may govern and control the retention mechanism.
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Affiliation(s)
- Mikołaj Dembek
- Chair of Environmental Chemistry and Bioanalytics, Faculty of Chemistry, Nicolaus Copernicus University, 7 Gagarin St., Toruń PL-87-100, Poland
| | - Ivett Bacskay
- HUN-REN-PTE Molecular Interactions in Separation Science Research Group, Ifjúság útja 6, Pécs H-7624, Hungary; Department of Analytical and Environmental Chemistry and Szentágothai Research Center, University of Pécs, Ifjúság útja 6, Pécs H-7624, Hungary
| | - Alessandro Buratti
- Department of Chemical, Pharmaceutical and Agricultural Sciences, University of Ferrara, via L. Borsari 46, Ferrara 44121, Italy
| | - Martina Catani
- Department of Chemical, Pharmaceutical and Agricultural Sciences, University of Ferrara, via L. Borsari 46, Ferrara 44121, Italy
| | - Attila Felinger
- HUN-REN-PTE Molecular Interactions in Separation Science Research Group, Ifjúság útja 6, Pécs H-7624, Hungary; Department of Analytical and Environmental Chemistry and Szentágothai Research Center, University of Pécs, Ifjúság útja 6, Pécs H-7624, Hungary; Institute of Bioanalysis, Medical School, University of Pécs, Szigeti út, Pécs H-7624, Hungary
| | - Bogusław Buszewski
- Chair of Environmental Chemistry and Bioanalytics, Faculty of Chemistry, Nicolaus Copernicus University, 7 Gagarin St., Toruń PL-87-100, Poland
| | - Szymon Bocian
- Chair of Environmental Chemistry and Bioanalytics, Faculty of Chemistry, Nicolaus Copernicus University, 7 Gagarin St., Toruń PL-87-100, Poland; Department of Analytical and Environmental Chemistry and Szentágothai Research Center, University of Pécs, Ifjúság útja 6, Pécs H-7624, Hungary.
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Dembek M, Bocian S. Phosphodiester Stationary Phases as Universal Chromatographic Materials for Separation in RP LC, HILIC, and Pure Aqueous Mobile Phase. MATERIALS (BASEL, SWITZERLAND) 2023; 16:ma16093539. [PMID: 37176421 PMCID: PMC10180384 DOI: 10.3390/ma16093539] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/07/2023] [Revised: 04/11/2023] [Accepted: 05/03/2023] [Indexed: 05/15/2023]
Abstract
Modern analytical chemistry techniques meet the need for greater attention to ecological and economic aspects. It is becoming necessary to seek solutions to reduce harmful waste production, especially in large quantities. High-performance liquid chromatography is a technique widely used in many industries, including mainly pharmaceuticals, and requires an approach to reduce the significant amount of organic solvent waste. One of the green chemistry solutions is using environmentally benign substitutes, such as pure water, supercritical dioxide, and ethanol. Our work focuses on the preparation and application of new stationary phases with embedded hydrophilic groups for separations using pure water in liquid chromatography. Polar-embedded stationary phases are obtained by attaching a phosphodiester group and 4 different hydrophobic molecules. The studies consisted of hydrophobicity measurements, concentration dependence of retention of the organic additive to the mobile phase, and chromatographic separations of polar and non-polar substance mixtures in RP-LC and HILIC systems. Three mixtures were studied: purine alkaloids, benzene, and polycyclic aromatic hydrocarbons and nucleosides. The stationary phases interact differently with the analytes depending on the attached hydrophobic group. It is possible to use pure water to separate each mixture under study. It is also significant that it has been possible to separate a mixture of completely non-polar compounds using pure water for the first time. The research being carried out is crucial in synthesizing new polar-embedded stationary phases, providing work versatility and high environmental performance.
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Affiliation(s)
- Mikołaj Dembek
- Chair of Environmental Chemistry and Bioanalysis, Faculty of Chemistry, Nicolaus Copernicus University, 7 Gagarina Str., 87-100 Torun, Poland
| | - Szymon Bocian
- Chair of Environmental Chemistry and Bioanalysis, Faculty of Chemistry, Nicolaus Copernicus University, 7 Gagarina Str., 87-100 Torun, Poland
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Kalisz O, Dembek M, Studzińska S, Bocian S. Beta-Blocker Separation on Phosphodiester Stationary Phases-The Application of Intelligent Peak Deconvolution Analysis. Molecules 2023; 28:molecules28073249. [PMID: 37050011 PMCID: PMC10096687 DOI: 10.3390/molecules28073249] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2023] [Revised: 03/28/2023] [Accepted: 03/30/2023] [Indexed: 04/14/2023] Open
Abstract
Beta-blockers are a class of medications predominantly used to manage abnormal heart rhythms. They are also widely used to treat high blood pressure. From the liquid chromatography separation point of view, beta-blockers are interesting molecules due to their hydrophobic-hydrophilic properties. Thus, the study aimed to investigate the beta-blocker separation selectivity on four phosphodiester stationary phases in reversed-phase liquid chromatography (RP LC) and hydrophilic interactions liquid chromatography (HILIC). On tested stationary phases, beta-blockers provide retention in both chromatographic systems, RP LC and HILIC. Additionally, it was found that cation-exchange mechanisms have a significant contribution to retention. Separations were enhanced by applying ChromSword software for gradient optimization and Intelligent Peak Deconvolution Analysis to separate unseparated peaks digitally.
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Affiliation(s)
- Oktawia Kalisz
- Chair of Environmental Chemistry and Bioanalytics, Faculty of Chemistry, Nicolaus Copernicus University, 7 Gagarin St., 87-100 Toruń, Poland
| | - Mikołaj Dembek
- Chair of Environmental Chemistry and Bioanalytics, Faculty of Chemistry, Nicolaus Copernicus University, 7 Gagarin St., 87-100 Toruń, Poland
| | - Sylwia Studzińska
- Chair of Environmental Chemistry and Bioanalytics, Faculty of Chemistry, Nicolaus Copernicus University, 7 Gagarin St., 87-100 Toruń, Poland
| | - Szymon Bocian
- Chair of Environmental Chemistry and Bioanalytics, Faculty of Chemistry, Nicolaus Copernicus University, 7 Gagarin St., 87-100 Toruń, Poland
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