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Sangawitayakorn C, Wilairat P, Chantiwas R. Experimental determination of phase ratio of C8 columns employing retention factors and octane-mobile phase partition coefficients of homologous series of linear alkylbenzenes. J Chromatogr A 2020; 1634:461668. [PMID: 33186883 DOI: 10.1016/j.chroma.2020.461668] [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: 04/30/2020] [Revised: 09/21/2020] [Accepted: 10/27/2020] [Indexed: 11/29/2022]
Abstract
This work proposes an experimental method for the estimation of the phase ratio of reversed-phase C8 columns by employing the equation log(k)=alog(Kom)+log(Φ), where k is the retention factor, Komis the octane-mobile phase partition coefficient, a is a proportionality constant and Φ is the phase ratio (defined as volume ratio of the stationary phase to the mobile phase). The immiscible liquid octane and mobile phase are chosen as the surrogate model for the C8 stationary phase and mobile phase of the chromatographic system. The octane-mobile phase is used for measuring the partition coefficient Kom of six compounds of the homologous series of linear alkylbenzenes, viz. benzene, toluene, ethylbenzene, propylbenzene, butylbenzene and pentylbenzene. The distribution of a compound between the octane and mobile phase is proposed to simulate the partitioning process in the chromatography. The retention factor k of each compound is measured using the same mobile phase for two C8 columns (Zorbax Eclipse XDB-C8 and Symmetry C8). The set of data of k and Kom is fitted to the above linear equation to give the best-fit values of a and log(Φ) for each column and various mobile phase compositions (methanol-water or acetonitrile-water). The regression analyses have coefficients of determination r2 > 0.992. This observed linear relationship can therefore be expressed as k=KomaΦ. The experimental values of Φ for the C8 columns are in the range of 0.206 to 0.842, with a from 0.544 to 0.811, respectively.
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Affiliation(s)
- Chaksawat Sangawitayakorn
- Department of Chemistry and Center of Excellence for Innovation in Chemistry and Flow Innovation-Research for Science and Technology Laboratories (FIRST Labs), Faculty of Science, Mahidol University, Rama VI Rd., Bangkok 10400, Thailand
| | - Prapin Wilairat
- Analytical Sciences and National Doping Test Institute, Mahidol University, Rama VI Rd., Bangkok 10400, Thailand.
| | - Rattikan Chantiwas
- Department of Chemistry and Center of Excellence for Innovation in Chemistry and Flow Innovation-Research for Science and Technology Laboratories (FIRST Labs), Faculty of Science, Mahidol University, Rama VI Rd., Bangkok 10400, Thailand.
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2
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Klimek-Turek A, Misiołek B, Dzido TH. Comparison of the Retention and Separation Selectivity of Aromatic Hydrocarbons with Polar Groups in RP-HPLC Systems with Different Stationary Phases and Eluents. Molecules 2020; 25:molecules25215070. [PMID: 33139630 PMCID: PMC7663032 DOI: 10.3390/molecules25215070] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2020] [Revised: 10/21/2020] [Accepted: 10/28/2020] [Indexed: 11/07/2022] Open
Abstract
In this manuscript, the retention of aromatic hydrocarbons with polar groups has been compared for systems with various nonpolar columns of the types from C3 to C18 and different mobile phases composed of methanol, acetonitrile, or tetrahydrofuran as modifiers. The selectivity separation of the solutes in systems with different adsorbents, when one eluent modifier is swapped by another, has been explained, taking into account molecular interactions of the solutes with components of the stationary phase region (i.e., extracted modifier depending on the chain length of the stationary phase).
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Affiliation(s)
- Anna Klimek-Turek
- Department of Physical Chemistry, Medical University of Lublin, Chodźki 4a, 20-093 Lublin, Poland; (B.M.); (T.H.D.)
- Correspondence: ; Tel.: +48-81448-7206
| | - Beata Misiołek
- Department of Physical Chemistry, Medical University of Lublin, Chodźki 4a, 20-093 Lublin, Poland; (B.M.); (T.H.D.)
- Department for Variations and Renewals of Medicinal Products, The Office for Registration of Medicinal Products, Medical Devices and Biocidal Products, Al. Jerozolimskie 181C, 02-222 Warsaw, Poland
| | - Tadeusz H. Dzido
- Department of Physical Chemistry, Medical University of Lublin, Chodźki 4a, 20-093 Lublin, Poland; (B.M.); (T.H.D.)
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3
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Soare AC, David V, Moldoveanu SC. Does phase ratio in reversed phase high performance liquid chromatography vary with temperature? J Chromatogr A 2020; 1620:461023. [PMID: 32173021 DOI: 10.1016/j.chroma.2020.461023] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2020] [Revised: 03/05/2020] [Accepted: 03/07/2020] [Indexed: 11/29/2022]
Abstract
Phase ratio Φ for an high performance liquid chromatography (HPLC) column is a parameter defined as the ratio between the volume of the stationary phase Vs and the void volume of the column Vm. Together with the equilibrium constant K of the separation process, phase ratio is part of the retention factor k (k = KΦ). Although a considerable number of studies have been dedicated to the evaluation of Vs and Vm with the goal of obtaining the value for Φ, there are still debatable results regarding the true value of Φ, which for a column with a specific stationary phase may vary with the composition of the mobile phase. One route for the evaluation of the value of Φ uses the measurements of retention factors k on a specific column and mobile phase for two or more hydrocarbons for which the octanol/water partition coefficients log Kow are known. This procedure has been applied in the present study for the evaluation of Φ for three commercially available C18 columns and two mobile phase compositions water/acetonitrile, in the temperature range 20 °C to 50 °C. It was found that phase ratio does change depending on the temperature, its "effective value" decreasing as the temperature increases which is in accordance with the decrease of retention times in reversed phase HPLC when the temperature increases. Besides other factors that may affect the correct calculation of thermodynamic functions, the change of phase ratio with temperature has implications regarding the possibility to calculate the enthalpy and entropy values from van't Hoff plots of the variation of log k as a function of 1/T, even when the retention process is dominated by unique hydrophobic type interactions.
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Affiliation(s)
| | - Victor David
- Department of Analytical Chemistry, University of Bucharest, Bucharest, Romania
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4
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Jandera P, Hájek T. Dual‐mode hydrophilic interaction normal phase and reversed phase liquid chromatography of polar compounds on a single column. J Sep Sci 2019; 43:70-86. [DOI: 10.1002/jssc.201900920] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2019] [Revised: 10/11/2019] [Accepted: 10/15/2019] [Indexed: 12/11/2022]
Affiliation(s)
- Pavel Jandera
- Department of Analytical ChemistryUniversity of Pardubice Pardubice Czech Republic
| | - Tomáš Hájek
- Department of Analytical ChemistryUniversity of Pardubice Pardubice Czech Republic
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5
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Grozdev L, Kaiser J, Berensmeier S. One-Step Purification of Microbially Produced Hydrophobic Terpenes via Process Chromatography. Front Bioeng Biotechnol 2019; 7:185. [PMID: 31417900 PMCID: PMC6681792 DOI: 10.3389/fbioe.2019.00185] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2019] [Accepted: 07/15/2019] [Indexed: 12/31/2022] Open
Abstract
Novel and existing terpenes are already being produced by genetically modified microorganisms, leading to new process challenges for the isolation and purification of these terpenes. Here, eight different chromatographic resins were characterized for the packed bed adsorption of the model terpene β-caryophyllene, showing their applicability on an Escherichia coli fermentation mixture. The polystyrenic Rensa® RP (Ø 50 μm) shows the highest affinity, with a maximum capacity of >100 g L-1 and the best efficiency, with a height equivalent of a theoretical plate (HETP) of 0.022 cm. With this material, an optimized adsorption-based purification of β-caryophyllene from a fermentation mixture was developed, with the green solvent ethanol for desorption. A final yield of >80% and a purity of >99% were reached after only one process step with a total productivity of 0.83 g h-1 L-1. The product solution was loaded with a volume ratio (feed to column) of >500 and the adapted gradient elution yielded a 40 times higher concentration of β-caryophyllene. The adsorption-based chromatography represents therefore a serious alternative to the liquid-liquid extraction and achieves desired purities without the utilization of hazardous solvents.
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Affiliation(s)
| | | | - Sonja Berensmeier
- Bioseparation Engineering Group, Department of Mechanical Engineering, Technical University of Munich, Garching, Germany
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Nekrasova NA, Kurbatova SV. Comparative Study of Quinolines and Tetrahydroquinolines Sorption on Various Sorbents from Water-Acetonitrile Solutions. J Chromatogr Sci 2019; 57:369-380. [PMID: 30615111 DOI: 10.1093/chromsci/bmy111] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2018] [Revised: 11/26/2018] [Accepted: 12/04/2018] [Indexed: 11/14/2022]
Abstract
The retention of 16 quinoline and tetrahydroquinoline derivatives was investigated under liquid chromatography conditions using porous graphitized carbon (PGC), octadecyl silica (ODS) and hypercrosslinked polystyrene (HCLP) stationary phases. For most of the analytes, retention on PGC was greater than on ODS, while retention on HCLP was even greater than on both ODS and PGC. The non-linearity of retention dependencies on acetonitrile content in the eluent was observed for compounds containing carboxy, hydrazo and methoxy groups. The relationships between quinolines structure and their retention factors were investigated. It was found that sorption on different sorbents correlated with different descriptors. Retention on ODS was found to be highly correlated with lipophilicity only while on HCLP it depended on both lipophilicity and polarizability of the sorbates. The feature of PGC was a good correlation of retention factors with topological and geometrical parameters. Additionally, ability of PGC to form OH…π bonds with hydroxymethylquinolines was found. The observed regularities allow one to rationally optimize the chromatographic analysis of structurally similar compounds, which is very important for bioactive substances.
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Affiliation(s)
- Nadezhda A Nekrasova
- Department of Physical Chemistry and Chromatography, Samara National Research University Named after Academician S.P. Korolev, 34 Moskovskoye Shosse, Samara, Russia.,Samara Center for Theoretical Material Science, 34 Moskovskoye Shosse, Samara, Russia
| | - Svetlana V Kurbatova
- Department of Physical Chemistry and Chromatography, Samara National Research University Named after Academician S.P. Korolev, 34 Moskovskoye Shosse, Samara, Russia
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Ohashi J, Harada M, Okada T. Excess Adsorption of Organic Eluent Components from Mobile Phases Containing Electrolytes. Chromatographia 2018. [DOI: 10.1007/s10337-018-3552-y] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/14/2022]
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8
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Ohashi J, Harada M, Okada T. A simple method for measuring excess adsorption isotherms of organic eluent components on reversed-phase packing materials. J Sep Sci 2016; 40:842-848. [PMID: 27990778 DOI: 10.1002/jssc.201601032] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2016] [Revised: 11/11/2016] [Accepted: 11/28/2016] [Indexed: 11/08/2022]
Abstract
A simple frontal analysis method has been developed for the reliable measurement of excess adsorption isotherms of an organic component on reversed-phase adsorbents in a series of programmed concentration steps. In the present method, a peak, which is produced by refractive index change in column eluate, is detected at 589 nm; it represents the elution volume of the boundary. The method is applied to the measurement of the excess adsorption isotherms of organic eluent components from water on commercially available reversed-phase stationary phases. The results are in good agreement with the previously reported isotherms. We also measure the excess adsorption isotherms of organic eluent components from solutions containing electrolytes. There are not any interference peaks on the elution traces. The method is thus reliably applicable to the evaluation of the excess adsorption of organic eluent components in practical systems.
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Affiliation(s)
- Junji Ohashi
- Department of Chemistry, Tokyo Institute of Technology, Tokyo, Japan.,Analytical and Quality Evaluation Research Laboratories, Daiichi Sankyo Co., Ltd., Hiratsuka, Japan
| | - Makoto Harada
- Department of Chemistry, Tokyo Institute of Technology, Tokyo, Japan
| | - Tetsuo Okada
- Department of Chemistry, Tokyo Institute of Technology, Tokyo, Japan
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Caiali E, David V, Aboul-Enein HY, Moldoveanu SC. Evaluation of the phase ratio for three C18 high performance liquid chromatographic columns. J Chromatogr A 2016; 1435:85-91. [PMID: 26818239 DOI: 10.1016/j.chroma.2016.01.043] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2015] [Revised: 01/12/2016] [Accepted: 01/14/2016] [Indexed: 11/29/2022]
Abstract
For a chromatographic column, phase ratio Φ is defined as the ratio between the volume of the stationary phase Vst and the void volume of the column V0, and it is an important parameter characterizing the HPLC process. Although apparently simple, the evaluation of Φ presents difficulties because there is no sharp boundary between the mobile phase and the stationary phase. In addition, the boundary depends not only on the nature of the stationary phase, but also on the composition of the mobile phase. In spite of its importance, phase ratio is seldom reported for commercially available HPLC columns and the data typically provided by the vendors about the columns do not provide key information that would allow the calculation of Φ based on Vst and V0 values. A different procedure for the evaluation of Φ is based on the following formula: log k'j=a log Kow,j+log Φ, where k'j is the retention factor for a compound j that must be a hydrocarbon, Kow,j is the octanol/water partition coefficient, and a is a proportionality constant. Present study describes the experimental evaluation of Φ based on the measurement of k'j for the compounds in the homologous series between benzene and butylbenzene for three C18 columns: Gemini C18, Luna C18 both with 5 μm particles, and a Chromolith Performance RP-18. The evaluation was performed for two mobile phase systems at different proportions of methanol/water and acetonitrile/water. The octanol/water partition coefficients were obtained from the literature. The results obtained in the study provide further support for the new procedure for the evaluation of phase ratio.
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Affiliation(s)
- Edvin Caiali
- University of Bucharest, Faculty of Chemistry, Department of Analytical Chemistry, Bucharest, Romania
| | - Victor David
- University of Bucharest, Faculty of Chemistry, Department of Analytical Chemistry, Bucharest, Romania
| | - Hassan Y Aboul-Enein
- National Research Centre, Pharmaceutical and Drug Industries Research Division, Pharmaceutical and Medicinal Chemistry Department, Cairo, Egypt
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10
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Moldoveanu S, David V. Estimation of the phase ratio in reversed-phase high-performance liquid chromatography. J Chromatogr A 2015; 1381:194-201. [DOI: 10.1016/j.chroma.2015.01.034] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2014] [Revised: 01/12/2015] [Accepted: 01/13/2015] [Indexed: 10/24/2022]
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11
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Han SY, Yu HM, Pei YQ, Chi YM. Selectivity-column temperature relationship as a new strategy in predicting separation of structural analogues in HPLC by using different stationary phases. RSC Adv 2015. [DOI: 10.1039/c5ra09524g] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
The effect of changes in column temperature on van't Hoff equation, as well as relationship of separation and column temperature in high performance liquid chromatography (HPLC) by using different stationary phases, have been discussed and compared.
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Affiliation(s)
- Shu-ying Han
- College of Pharmacy
- Nanjing University of Chinese Medicine
- Nanjing 210023
- China
| | - Hui-min Yu
- College of Pharmacy
- Nanjing University of Chinese Medicine
- Nanjing 210023
- China
| | - Yu-qiong Pei
- College of Pharmacy
- Nanjing University of Chinese Medicine
- Nanjing 210023
- China
| | - Yu-mei Chi
- College of Pharmacy
- Nanjing University of Chinese Medicine
- Nanjing 210023
- China
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