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Enmark M, Samuelsson J, Fornstedt T. A Retention-Matching Strategy for Method Transfer in Supercritical Fluid Chromatography: Introducing the Isomolar Plot Approach. Anal Chem 2021; 93:6385-6393. [PMID: 33844504 PMCID: PMC8153393 DOI: 10.1021/acs.analchem.0c05142] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
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A strategy to match
any retention shifts due to increased or decreased
pressure drop during supercritical fluid chromatography (SFC) method
transfer is presented. The strategy relies on adjusting the co-solvent
molarity without the need to adjust the back-pressure regulator. Exact
matching can be obtained with minimal changes in separation selectivity.
To accomplish this, we introduce the isomolar plot approach, which
shows the variation in molar co-solvent concentration depending on
the mass fraction of co-solvent, pressure, and temperature, here exemplified
by CO2–methanol. This plot allowed us to unify the
effects of the co-solvent mass fraction and density on retention in
SFC. The approach, which was verified on 12 known empirical retention
models for each enantiomer of six basic pharmaceuticals, allowed us
to numerically calculate the apparent retention factor for any column
pressure drop. The strategy can be implemented either using a mechanistic
approach if retention models are known or empirically by iteratively
adjusting the co-solvent mass fraction. As a rule of thumb for the
empirical approach, we found that the relative mass fraction adjustment
needed is proportional to the relative change in the retention factor
caused by a change in the pressure drop. Different proportionality
constants were required to match retention in the case of increasing
or decreasing pressure drops.
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Affiliation(s)
- Martin Enmark
- Department of Engineering and Chemical Sciences, Karlstad University, Karlstad SE-651 88, Sweden
| | - Jörgen Samuelsson
- Department of Engineering and Chemical Sciences, Karlstad University, Karlstad SE-651 88, Sweden
| | - Torgny Fornstedt
- Department of Engineering and Chemical Sciences, Karlstad University, Karlstad SE-651 88, Sweden
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2
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Johansson E, Karlsson A, Ludvigsson JW. Ultra high performance liquid chromatography method development for separation of omeprazole and related substances on core‐shell columns using a Quality by Design approach. J Sep Sci 2020; 43:696-707. [DOI: 10.1002/jssc.201900726] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2019] [Revised: 11/08/2019] [Accepted: 11/11/2019] [Indexed: 12/28/2022]
Affiliation(s)
- Emma Johansson
- Global Product DevelopmentPharmaceutical Technology and DevelopmentAstraZeneca R&D Gothenburg Mölndal Sweden
| | - Anders Karlsson
- Global Product DevelopmentPharmaceutical Technology and DevelopmentAstraZeneca R&D Gothenburg Mölndal Sweden
| | - Jufang Wu Ludvigsson
- Manufacturing Science and TechnologyPharmaceutical Technology and DevelopmentAstraZeneca R&D Gothenburg Mölndal Sweden
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3
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Samuelsson J, Eiriksson FF, Åsberg D, Thorsteinsdóttir M, Fornstedt T. Determining gradient conditions for peptide purification in RPLC with machine-learning-based retention time predictions. J Chromatogr A 2019; 1598:92-100. [DOI: 10.1016/j.chroma.2019.03.043] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2019] [Revised: 03/20/2019] [Accepted: 03/21/2019] [Indexed: 01/22/2023]
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4
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Horváth K, Vajda P, Felinger A. Multilayer adsorption in liquid chromatography - The surface heterogeneity below an adsorbed multilayer. J Chromatogr A 2017; 1505:50-55. [PMID: 28528681 DOI: 10.1016/j.chroma.2017.05.020] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2017] [Revised: 04/27/2017] [Accepted: 05/07/2017] [Indexed: 11/20/2022]
Abstract
A numerical method was introduced for the estimation of the surface heterogeneity below an adsorbed multilayer of the analyte. The calculation procedure is based on the raw adsorption isotherm data points obtained by frontal analysis experiments. To permit the mapping of the nature of the analyte-surface interaction, a numerical procedure was used to pre-estimate the adsorbate-adsorbate interactions occurring during the adsorption process. The surface heterogeneity estimation was carried out using the affinity-energy distribution calculations with assuming local BET isotherm. In the local BET isotherm the pre-estimated adsorbate-adsorbate interaction constant was used, and the surface heterogeneity was described. After the test of the numerical method with benchmark isotherms, the algorithm was tested on several experimental isotherms. The isotherms were measured using phenol as test molecule on reversed phase adsorbents, with different surface coverage of the octadecyl ligands. The surface of the non-end-capped stationary phases showed detectable heterogeneity, while the surface end-capped phases were found to be homogeneous.
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Affiliation(s)
- Krisztián Horváth
- Department of Analytical Chemistry, University of Pannonia, Egyetem utca 10, H-8200 Veszprém, Hungary
| | - Péter Vajda
- MTA-PTE Molecular Interactions in Separation Science Research Group, Ifjúság útja 6, H-7624 Pécs, Hungary
| | - Attila Felinger
- MTA-PTE Molecular Interactions in Separation Science Research Group, Ifjúság útja 6, H-7624 Pécs, Hungary; Department of Analytical and Environmental Chemistry and Szentágothai Research Center, University of Pécs, Ifjúság útja 6, H-7624 Pécs, Hungary.
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5
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Ahmad IAH, Hrovat F, Soliven A, Clarke A, Boswell P, Tarara T, Blasko A. A 14 Parameter Study of UHPLC’s for Method Development Transfer and Troubleshooting. Chromatographia 2017. [DOI: 10.1007/s10337-017-3337-8] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
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6
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Åsberg D, Leśko M, Leek T, Samuelsson J, Kaczmarski K, Fornstedt T. Estimation of Nonlinear Adsorption Isotherms in Gradient Elution RP-LC of Peptides in the Presence of an Adsorbing Additive. Chromatographia 2017; 80:961-966. [PMID: 28725083 PMCID: PMC5486455 DOI: 10.1007/s10337-017-3298-y] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2016] [Revised: 03/13/2017] [Accepted: 03/17/2017] [Indexed: 11/25/2022]
Abstract
ABSTRACT In electrostatic repulsive interaction chromatography, using a charged surface hybrid sorbent carrying positive charges can improve the peak shape of peptides in reversed-phase liquid chromatography (RP-LC), especially in overloaded conditions, compared with standard C18 sorbents. However, the positive surface charges can interact with anionic additives commonly used in peptide separations, e.g., trifluoroacetic acid (TFA), complicating adsorption isotherm estimation. We investigated how the competition for available adsorption sites between TFA and two peptides influenced the adsorption isotherm in gradient elution. A model accounting for the competition with TFA was compared with a model neglecting TFA adsorption. We found that the two models predicted elution profiles with the same accuracy. We also found that the adsorption isotherms were extremely similar in shape, leading to the conclusion that neglecting the competition with TFA is a valid approximation enabling faster and more robust adsorption isotherm estimation for the studied type of sorbent. GRAPHICAL ABSTRACT
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Affiliation(s)
- Dennis Åsberg
- Department of Engineering and Chemical Sciences, Karlstad University, 651 88 Karlstad, Sweden
| | - Marek Leśko
- Department of Chemical and Process Engineering, Rzeszów University of Technology, 359 59 Rzeszów, Poland
| | - Tomas Leek
- Respiratory, Inflammation and Autoimmunity, Innovative Medicines and Early Development Biotech Unit, AstraZeneca, 431 83 Mölndal, Sweden
| | - Jörgen Samuelsson
- Department of Engineering and Chemical Sciences, Karlstad University, 651 88 Karlstad, Sweden
| | - Krzysztof Kaczmarski
- Department of Chemical and Process Engineering, Rzeszów University of Technology, 359 59 Rzeszów, Poland
| | - Torgny Fornstedt
- Department of Engineering and Chemical Sciences, Karlstad University, 651 88 Karlstad, Sweden
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7
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Åsberg D, Langborg Weinmann A, Leek T, Lewis RJ, Klarqvist M, Leśko M, Kaczmarski K, Samuelsson J, Fornstedt T. The importance of ion-pairing in peptide purification by reversed-phase liquid chromatography. J Chromatogr A 2017; 1496:80-91. [PMID: 28363419 DOI: 10.1016/j.chroma.2017.03.041] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2016] [Revised: 03/07/2017] [Accepted: 03/18/2017] [Indexed: 10/19/2022]
Abstract
The adsorption mechanism for three peptides was studied under overloaded conditions through adsorption isotherm measurements in the presence of an ion-pairing reagent, trifluoroacetic acid (TFA), on an end-capped C18-bonded stationary phase. The overall aim of the study was to obtain a better understanding of how the acetonitrile and the TFA fractions in the eluent affected the overloaded elution profiles and the selectivity between peptides using mechanistic modelling and multivariate design of experiments. When studying the effect of TFA, direct evidence for ion pair formation between a peptide and TFA in acetonitrile-water solutions was provided by fluorine-proton nuclear Overhauser NMR enhancement experiments and the adsorption of TFA on the stationary phase was measured by frontal analysis. The adsorption isotherms for each peptide were then determined by the inverse method at eight TFA concentrations ranging from 2.6mM to 37.3mM (0.02-0.29vol-%) in isocratic elution. The equilibrium between the peptide ion and the peptide-TFA complex was modelled by coupling the mass-balance to reaction kinetics and determining separate adsorption isotherms for the two species. We found that a Langmuir isotherm described the elution profile of peptide-TFA complex well while the peptide ion was described by a bi-Langmuir adsorption isotherm since it exhibited strong secondary interactions. The elution profiles had an unfavorable shape at low TFA concentrations consisting of a spike in their front and a long tailing rear due to the secondary interactions for the peptide ion having very low saturation capacity. The acetonitrile dependence on the adsorption isotherms was studied by determination of adsorption isotherms directly from elution profiles obtained in gradient elution which enabled a broad acetonitrile interval to be studied. Here, it was found that the column saturation capacity was quickly reached at very low acetonitrile fractions and that there were significant variations in adsorption with the molecular weight. Finally, practical implications for method development are discussed based on an experimental design where gradient slope and TFA concentrations are used as factors.
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Affiliation(s)
- Dennis Åsberg
- Department of Engineering and Chemical Sciences, Karlstad University, SE-651 88 Karlstad, Sweden
| | - Annika Langborg Weinmann
- Respiratory, Inflammation and Autoimmunity, Innovative Medicines and Early Development Biotech Unit, AstraZeneca, SE 431 83 Mölndal, Sweden
| | - Tomas Leek
- Respiratory, Inflammation and Autoimmunity, Innovative Medicines and Early Development Biotech Unit, AstraZeneca, SE 431 83 Mölndal, Sweden
| | - Richard J Lewis
- Respiratory, Inflammation and Autoimmunity, Innovative Medicines and Early Development Biotech Unit, AstraZeneca, SE 431 83 Mölndal, Sweden
| | - Magnus Klarqvist
- Respiratory, Inflammation and Autoimmunity, Innovative Medicines and Early Development Biotech Unit, AstraZeneca, SE 431 83 Mölndal, Sweden
| | - Marek Leśko
- Department of Chemical and Process Engineering, Rzeszów University of Technology, PL-359 59 Rzeszów, Poland
| | - Krzysztof Kaczmarski
- Department of Chemical and Process Engineering, Rzeszów University of Technology, PL-359 59 Rzeszów, Poland
| | - Jörgen Samuelsson
- Department of Engineering and Chemical Sciences, Karlstad University, SE-651 88 Karlstad, Sweden
| | - Torgny Fornstedt
- Department of Engineering and Chemical Sciences, Karlstad University, SE-651 88 Karlstad, Sweden.
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8
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Åsberg D, Chutkowski M, Leśko M, Samuelsson J, Kaczmarski K, Fornstedt T. A practical approach for predicting retention time shifts due to pressure and temperature gradients in ultra-high-pressure liquid chromatography. J Chromatogr A 2017; 1479:107-120. [DOI: 10.1016/j.chroma.2016.11.050] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2016] [Revised: 11/22/2016] [Accepted: 11/24/2016] [Indexed: 10/20/2022]
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9
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A quality control method enhancement concept—Continual improvement of regulatory approved QC methods. J Pharm Biomed Anal 2016; 129:273-281. [DOI: 10.1016/j.jpba.2016.06.018] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2016] [Revised: 06/08/2016] [Accepted: 06/10/2016] [Indexed: 11/20/2022]
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10
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Combining Chemometric Models with Adsorption Isotherm Measurements to Study Omeprazole in RP-LC. Chromatographia 2016; 79:1283-1291. [PMID: 27738352 PMCID: PMC5039227 DOI: 10.1007/s10337-016-3151-8] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2016] [Revised: 06/21/2016] [Accepted: 06/26/2016] [Indexed: 11/25/2022]
Abstract
The adsorption of the proton-pump inhibitor omeprazole was investigated using RP-LC with chemometric models combined with adsorption isotherm modelling to study the effect of pH and type of organic modifier (i.e., acetonitrile or methanol). The chemometric approach revealed that omeprazole was tailing with methanol and fronting with acetonitrile along with increased fronting at higher pH. The increased fronting with higher pH for acetonitrile was explored using a pH-dependent adsorption isotherm model that was determined using the inverse method and it agreed well with the experimental data. The model indicated that the peaks exhibit more fronting at high pH due to a larger fraction of charged omeprazole molecules. This model could accurately predict the shape of elution profiles at arbitrary pH levels in the studied interval. Using a two-layer adsorption isotherm model, the difference between acetonitrile and methanol was studied at the lowest pH at which almost all omeprazole molecules are neutral. Omeprazole had adsorbate–adsorbate interactions that were similar in strength for the acetonitrile and methanol mobile phases, while the solute–adsorbent interactions were almost twice as strong with methanol. The difference in the relative strengths of these two interactions likely explains the different peak asymmetries (i.e., tailing/fronting) in methanol and acetonitrile. In conclusion, thermodynamic modelling can complement chemometric modeling in HPLC method development and increase the understanding of the separation.
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11
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ÿsberg D, Samuelsson J, Fornstedt T. A fundamental study of the impact of pressure on the adsorption mechanism in reversed-phase liquid chromatography. J Chromatogr A 2016; 1457:97-106. [DOI: 10.1016/j.chroma.2016.06.036] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2016] [Revised: 06/10/2016] [Accepted: 06/12/2016] [Indexed: 11/30/2022]
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12
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Analytical advances in pharmaceutical impurity profiling. Eur J Pharm Sci 2016; 87:118-35. [DOI: 10.1016/j.ejps.2015.12.007] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2015] [Revised: 11/14/2015] [Accepted: 12/05/2015] [Indexed: 01/11/2023]
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13
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Leśko M, Åsberg D, Enmark M, Samuelsson J, Fornstedt T, Kaczmarski K. Choice of Model for Estimation of Adsorption Isotherm Parameters in Gradient Elution Preparative Liquid Chromatography. Chromatographia 2015; 78:1293-1297. [PMID: 26435545 PMCID: PMC4580716 DOI: 10.1007/s10337-015-2949-0] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2015] [Accepted: 07/14/2015] [Indexed: 11/24/2022]
Abstract
The inverse method is a numerical method for fast estimation of adsorption isotherm parameters directly from a few overloaded elution profiles and it was recently extended to adsorption isotherm acquisition in gradient elution conditions. However, the inverse method in gradient elution is cumbersome due to the complex adsorption isotherm models found in gradient elution. In this case, physicochemically correct adsorption models have very long calculation times. The aim of this study is to investigate the possibility of using a less complex adsorption isotherm model, with fewer adjustable parameters, but with preserved/acceptable predictive abilities. We found that equal or better agreement between experimental and predicted elution profiles could be achieved with less complex models. By being able to select a model with fewer adjustable parameters, the calculation times can be reduced by at least a factor of 10.
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Affiliation(s)
- Marek Leśko
- Department of Chemical and Process Engineering, Rzeszów University of Technology, 35 959 Rzeszów, Poland
| | - Dennis Åsberg
- Department of Engineering and Chemical Sciences, INTERACT, Karlstad University, 651 88 Karlstad, Sweden
| | - Martin Enmark
- Department of Engineering and Chemical Sciences, INTERACT, Karlstad University, 651 88 Karlstad, Sweden
| | - Jörgen Samuelsson
- Department of Engineering and Chemical Sciences, INTERACT, Karlstad University, 651 88 Karlstad, Sweden
| | - Torgny Fornstedt
- Department of Engineering and Chemical Sciences, INTERACT, Karlstad University, 651 88 Karlstad, Sweden
| | - Krzysztof Kaczmarski
- Department of Chemical and Process Engineering, Rzeszów University of Technology, 35 959 Rzeszów, Poland
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14
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Method transfer from high-pressure liquid chromatography to ultra-high-pressure liquid chromatography. II. Temperature and pressure effects. J Chromatogr A 2015; 1401:52-9. [DOI: 10.1016/j.chroma.2015.05.002] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2014] [Revised: 04/30/2015] [Accepted: 05/01/2015] [Indexed: 11/20/2022]
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