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Leśko M, Kaczmarski K, Samuelsson J, Fornstedt T. Prediction of overloaded concentration profiles under ultra-high-pressure liquid chromatographic conditions. J Chromatogr A 2024; 1718:464704. [PMID: 38330725 DOI: 10.1016/j.chroma.2024.464704] [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: 09/26/2023] [Revised: 01/29/2024] [Accepted: 01/30/2024] [Indexed: 02/10/2024]
Abstract
In this study, overloaded elution profiles under ultra-high-pressure liquid chromatographic (UHPLC) conditions and accounting for the severe pressure and temperature gradients generated, are compared with experimental data. The model system consisted of an C18 column packed with 1.7-µm particles (i.e., a UHPLC column) and the solute was 1,3,5-tri‑tert-butylbenzene eluted with a mobile phase composed of 85/15 (v/v) acetonitrile/water. Two thermal modes were considered, and the solute was eluted at the very high inlet pressures necessary to achieve a highly efficient and rapid chromatographic process, as provided by using columns packed with small particles. However, the high inlet pressure and high linear velocity of the mobile phase caused the production of a significant amount of heat, and consequently, the formation of axial and radial temperature gradients. Due to these gradients, the retention and the mobile phase velocity were no longer constant. Thus, simple mathematical models consisting only of the mass balance equations are unsuitable to properly model the elution profiles. Here, the elution concentration profiles were predicted using a combined two-dimensional heat and mass transfer model, also including the calculation of the mobile phase velocity distribution. The isotherm adsorption model was the bi-Langmuir isotherm model with Henry constants that depended on the local temperature and pressure in the column. These adjustments allowed us to precisely account for changes in the shape and retention of the overloaded concentration profiles in the mobile phase. The proposed model provided accurate predictions of the overloaded concentration profiles, demonstrating good agreement with experimental profiles eluted under severe pressure and temperature gradients in the column even in the most extreme cases where the pressure drops reached 846 bar and the temperature gradients equaled 0.15 K mm-1 and 0.95 K mm-1 in the axial and the radial directions, respectively. In such cases 36 % decrease of the retention factor was observed along the column and 2 % increase in radial direction. These changes, combined with the velocity distribution, shifted the overloaded elution profile's shock towards the center of the column, advancing approximately 3 mm from its initial position close to the column wall. Ultimately, this resulted in the broadening of the elution band.
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Affiliation(s)
- Marek Leśko
- Department of Engineering and Chemical Sciences, Karlstad University, SE-651 88 Karlstad, Sweden
| | - Krzysztof Kaczmarski
- Department of Chemical and Process Engineering, Rzeszów University of Technology, PL-35 959 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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Farsang E, Lukács D, József S, Horváth K. Effect of time-invariant pressure gradients on peak formation and efficiency in ultrahigh-pressure liquid chromatography. J Chromatogr A 2023; 1704:464135. [PMID: 37302250 DOI: 10.1016/j.chroma.2023.464135] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2023] [Revised: 06/02/2023] [Accepted: 06/04/2023] [Indexed: 06/13/2023]
Abstract
In chromatography, pressure can affect the retention factors of compounds significantly. In liquid chromatography, this effect is primarily related to the change in the molecular volume of solute during adsorption that is remarkably high for large biomolecules such as peptides and proteins. As a result, the migration velocities of chromatographic bands vary spatially through the column affecting the degree of band broadening. In this work, based on theoretical considerations, chromatographic efficiencies are studied under pressure-induced gradient conditions. The retention factor and migration velocity of different components are examined, and it is shown that components with the same retention time can have different migration patterns. The width of the initial band after injection is affected by the pressure gradient, providing significantly thinner initial bands for compounds with higher pressure sensitivity. In addition to classical band broadening phenomena, the influence of pressure gradients on band broadening is remarkable. The positive velocity gradient leads to extra band broadening. Our results clearly demonstrate that the zones are significantly wider at the end of the column if the change of molar volume of solute during adsorption is large. If the pressure drop is increasing, this effect becomes more significant. In the same time, the high release velocity of the bands somewhat counteracts the extra band broadening effect, however, it can not offset it perfectly. As a result, the separation efficiency of large biomolecules is decreased significantly due to the chromatographic pressure gradient. Under UHPLC conditions, the extent of apparent efficiency loss can reach up to 50% compared to the intrinsic efficiency of the column.
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Affiliation(s)
- Evelin Farsang
- Research Group of Analytical Chemistry, University of Pannonia, Egyetem u. 10, H-8200 Veszprém, Hungary
| | - Diána Lukács
- Research Group of Analytical Chemistry, University of Pannonia, Egyetem u. 10, H-8200 Veszprém, Hungary
| | - Simon József
- Research Group of Analytical Chemistry, University of Pannonia, Egyetem u. 10, H-8200 Veszprém, Hungary; MS Metabolomics Research Laboratory, Centre for Structural Science, Magyar tudósok körútja 2, H-1117 Budapest, Hungary
| | - Krisztián Horváth
- Research Group of Analytical Chemistry, University of Pannonia, Egyetem u. 10, H-8200 Veszprém, Hungary.
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3
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Moussa A, Deridder S, Broeckhoven K, Desmet G. Detailed computational fluid dynamics study of the parameters contributing to the viscous heating band broadening in liquid chromatography at pressures up to 2500 bar in 2.1 mm columns. J Chromatogr A 2021; 1661:462683. [PMID: 34883357 DOI: 10.1016/j.chroma.2021.462683] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2021] [Revised: 11/10/2021] [Accepted: 11/11/2021] [Indexed: 10/19/2022]
Abstract
Over the past years viscous heating band broadening occurring in high pressure liquid chromatography has been studied extensively. In the present numerical study, we investigate the fine details of this band broadening contribution under extreme high-pressure conditions (2500 bar). To analyze the results, we first show that viscous heating leads to two clearly distinguishable band broadening effects, one originating from the radial differences in the species migration velocity and the other from the axial variations. It was found that the radial contribution is independent of the intrinsic band broadening of the bed (i.e. band broadening in absence of viscous heating) while it strongly depends on the radial dispersion coefficient and the retention enthalpy of the analytes. On the other hand, the axial contribution is strongly dependent on the bed intrinsic band broadening and it is found to be 4 to 5 times lower than the radial contribution. We also show the strong effect of the endfittings on the temperature gradients inside the column thus on the resulting viscous heating band broadening.
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Affiliation(s)
- Ali Moussa
- Vrije Universiteit Brussel, Pleinlaan 2, 1050 Brussel, Belgium
| | - Sander Deridder
- KU Leuven, Department of Chemical Engineering, Process and Environmental Technology Lab, J. De Nayerlaan 5, 2860 Sint-Katelijne-Waver, Belgium
| | - Ken Broeckhoven
- Vrije Universiteit Brussel, Pleinlaan 2, 1050 Brussel, Belgium
| | - Gert Desmet
- Vrije Universiteit Brussel, Pleinlaan 2, 1050 Brussel, Belgium.
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4
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Computational fluid dynamics study of potential solutions to alleviate viscous heating band broadening in 2.1 millimeter liquid chromatography columns. J Chromatogr A 2021; 1654:462452. [PMID: 34392122 DOI: 10.1016/j.chroma.2021.462452] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2021] [Revised: 08/03/2021] [Accepted: 08/04/2021] [Indexed: 01/19/2023]
Abstract
We report on a numerical simulation study of a number of potential column technology solutions to minimize the plate height contribution (Hvh) originating from the use of ultra-high pressures and their concomitant viscous heating effect. Looking as far as possible into the future of UHPLC, all main results are obtained for the case of a 2500 bar pressure gradient. However, to generalize the result, a correlation is given that can be used to interpolate the results to lower pressures with some 10% accuracy. For the considered case of a 2.1mm column, a liquid flow rate of 0.45 ml/min, an analyte with retention factor k(25°C)=3 and a retention enthalpy chosen such that ΔHR/R= -1000 K, it is found that, in order to keep the global plate height as measured at the column outlet (Hvh,glob,out) below 1 μm, the bed conductivity would need to be raised to λbed=2.4 W/m•K, i.e., 4 times higher than a typical packed bed of fully-porous or core-shell silica particles. An equivalent effect on the band broadening could be obtained if it would be possible to replace the steel column wall with a low conductivity material. In this case, a wall conductivity of 0.25 W/m•K, i.e., 64 times smaller than the conductivity of steel, would be needed to keep Hvh,glob,out below 1 μm. Results are also interpreted based on contour plots of the axial and radial velocity variation of a retained analyte.
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Bupp CR, Wirth MJ. Making Sharper Peaks for Reverse-Phase Liquid Chromatography of Proteins. ANNUAL REVIEW OF ANALYTICAL CHEMISTRY (PALO ALTO, CALIF.) 2020; 13:363-380. [PMID: 32109149 DOI: 10.1146/annurev-anchem-061318-115009] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Protein separations have gained increasing interest over the past two decades owing to the dramatic growth of proteins as therapeutics and the completion of the Human Genome Project. About every decade, the field of protein high-performance liquid chromatography (HPLC) seems to mature, having reached what appears to be a theoretical limit. But then scientists well versed in the basic principles of HPLC invented a way around the limit, generating another decade of exciting progress. There is still the need for higher resolution and better compatibility with mass spectrometry because it is an essential tool for identification of proteins and their modifications. To make advances, the fundamental principles need to be understood. This review covers recent advances and current needs in the context of the principles that underlie the many contributions to peak broadening.
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Affiliation(s)
- Charles R Bupp
- Department of Chemistry, Purdue University, West Lafayette, Indiana 47907, USA;
| | - Mary J Wirth
- Department of Chemistry, Purdue University, West Lafayette, Indiana 47907, USA;
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Leśko M, Samuelsson J, Åsberg D, Kaczmarski K, Fornstedt T. Evaluating the advantages of higher heat conductivity in a recently developed type of core-shell diamond stationary phase particle in UHPLC. J Chromatogr A 2020; 1625:461076. [PMID: 32291077 DOI: 10.1016/j.chroma.2020.461076] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2019] [Revised: 03/03/2020] [Accepted: 03/24/2020] [Indexed: 01/04/2023]
Abstract
In recent studies, the nature and magnitude of the temperature gradients developed in ultra-high pressure liquid chromatography (UHPLC), were found to be dependent on the heat conductivity properties of the column matrices, but also, on the principle used for controlling the temperature over the column. Here, we investigated the potential of using highly heat conductive diamond-based stationary phases (85 times higher than silica), for reducing the temperature gradients. The stationary phases investigated were a (i) Diamond Analytics FLARE column, based on particles comprised of a graphite core surrounded by a very thin diamond shell, and two silica hybrid columns: (ii) a core-shell silica Kromasil Eternity Shell column and (iii) a fully porous silica Kromasil Eternity XT column. Models were developed based on two-dimensional heat transfer theory and mass transfer theory, which were used to model the temperature profiles and the migration of an analyte band accounting for column efficiencies at different flow rates. For the silica-based columns, using water-controlled temperature mode, the temperature gradients along the column axes are suppressed whereas temperature gradients in the radial direction prevails resulting in decreased column efficiencies. Using these columns with air-controlled temperature mode, the radial temperature gradients are reduced whereas temperature gradients along the column prevails resulting in decreased retention times. With the Diamond FLARE column, there was no loss in column efficiency using the water-controlled temperature mode and the van Deemter curves are almost identical using both temperature control modes. Thus, for the Diamond FLARE column, in contrast to the silica-based columns, there are almost no losses of column efficiencies due to reduced radial temperature gradients independent on how the column temperature was controlled.
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Affiliation(s)
- Marek Leśko
- Department of Engineering and Chemical Sciences, Karlstad University, SE-651 88 Karlstad, Sweden; Department of Chemical Engineering, Rzeszów University of Technology, PL-35 959 Rzeszów, Poland
| | - Jörgen Samuelsson
- Department of Engineering and Chemical Sciences, Karlstad University, SE-651 88 Karlstad, Sweden
| | - Dennis Åsberg
- Department of Engineering and Chemical Sciences, Karlstad University, SE-651 88 Karlstad, Sweden
| | - Krzysztof Kaczmarski
- Department of Chemical Engineering, Rzeszów University of Technology, PL-35 959 Rzeszów, Poland.
| | - Torgny Fornstedt
- Department of Engineering and Chemical Sciences, Karlstad University, SE-651 88 Karlstad, Sweden.
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7
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D’Atri V, Fekete S, Clarke A, Veuthey JL, Guillarme D. Recent Advances in Chromatography for Pharmaceutical Analysis. Anal Chem 2018; 91:210-239. [DOI: 10.1021/acs.analchem.8b05026] [Citation(s) in RCA: 55] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Affiliation(s)
- Valentina D’Atri
- School of Pharmaceutical Sciences, University of Geneva, University of Lausanne, CMU-Rue Michel Servet 1, 1211 Geneva 4, Switzerland
| | - Szabolcs Fekete
- School of Pharmaceutical Sciences, University of Geneva, University of Lausanne, CMU-Rue Michel Servet 1, 1211 Geneva 4, Switzerland
| | - Adrian Clarke
- Novartis Pharma AG, Technical Research and Development, Chemical and Analytical Development (CHAD), Basel, CH4056, Switzerland
| | - Jean-Luc Veuthey
- School of Pharmaceutical Sciences, University of Geneva, University of Lausanne, CMU-Rue Michel Servet 1, 1211 Geneva 4, Switzerland
| | - Davy Guillarme
- School of Pharmaceutical Sciences, University of Geneva, University of Lausanne, CMU-Rue Michel Servet 1, 1211 Geneva 4, Switzerland
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Using Superficially Porous Particles and Ultrahigh Pressure Liquid Chromatography in Pharmacopeial Monograph Modernization of Common Analgesics. Chromatographia 2018. [DOI: 10.1007/s10337-018-3593-2] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
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9
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Lambert N, Felinger A. The effect of the frictional heat on retention and efficiency in thermostated or insulated chromatographic columns packed with sub-2-μm particles. J Chromatogr A 2018; 1565:89-95. [DOI: 10.1016/j.chroma.2018.06.038] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2018] [Revised: 06/11/2018] [Accepted: 06/16/2018] [Indexed: 11/28/2022]
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10
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Groskreutz SR, Horner AR, Weber SG. Development of a 1.0 mm inside diameter temperature-assisted focusing precolumn for use with 2.1 mm inside diameter columns. J Chromatogr A 2017; 1523:193-203. [DOI: 10.1016/j.chroma.2017.07.015] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2017] [Revised: 07/03/2017] [Accepted: 07/05/2017] [Indexed: 01/16/2023]
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11
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Broeckhoven K, Desmet G. Considerations for the use of ultra-high pressures in liquid chromatography for 2.1 mm inner diameter columns. J Chromatogr A 2017; 1523:183-192. [DOI: 10.1016/j.chroma.2017.07.040] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2017] [Revised: 07/10/2017] [Accepted: 07/11/2017] [Indexed: 10/19/2022]
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12
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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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13
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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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14
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Astefanei A, Dapic I, Camenzuli M. Different Stationary Phase Selectivities and Morphologies for Intact Protein Separations. Chromatographia 2016; 80:665-687. [PMID: 28529348 PMCID: PMC5413533 DOI: 10.1007/s10337-016-3168-z] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2016] [Revised: 08/17/2016] [Accepted: 09/06/2016] [Indexed: 12/18/2022]
Abstract
The central dogma of biology proposed that one gene encodes for one protein. We now know that this does not reflect reality. The human body has approximately 20,000 protein-encoding genes; each of these genes can encode more than one protein. Proteins expressed from a single gene can vary in terms of their post-translational modifications, which often regulate their function within the body. Understanding the proteins within our bodies is a key step in understanding the cause, and perhaps the solution, to disease. This is one of the application areas of proteomics, which is defined as the study of all proteins expressed within an organism at a given point in time. The human proteome is incredibly complex. The complexity of biological samples requires a combination of technologies to achieve high resolution and high sensitivity analysis. Despite the significant advances in mass spectrometry, separation techniques are still essential in this field. Liquid chromatography is an indispensable tool by which low-abundant proteins in complex samples can be enriched and separated. However, advances in chromatography are not as readily adapted in proteomics compared to advances in mass spectrometry. Biologists in this field still favour reversed-phase chromatography with fully porous particles. The purpose of this review is to highlight alternative selectivities and stationary phase morphologies that show potential for application in top-down proteomics; the study of intact proteins.
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Affiliation(s)
- A. Astefanei
- Centre for Analytical Science in Amsterdam (CASA), Van’t Hoff Institute for Molecular Sciences, University of Amsterdam, Science Park 904, 1098 XH Amsterdam, The Netherlands
| | - I. Dapic
- Centre for Analytical Science in Amsterdam (CASA), Van’t Hoff Institute for Molecular Sciences, University of Amsterdam, Science Park 904, 1098 XH Amsterdam, The Netherlands
| | - M. Camenzuli
- Centre for Analytical Science in Amsterdam (CASA), Van’t Hoff Institute for Molecular Sciences, University of Amsterdam, Science Park 904, 1098 XH Amsterdam, The Netherlands
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15
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Grinias JP, Wong JMT, Kennedy RT. Repeatability of gradient ultrahigh pressure liquid chromatography-tandem mass spectrometry methods in instrument-controlled thermal environments. J Chromatogr A 2016; 1461:42-50. [PMID: 27457561 DOI: 10.1016/j.chroma.2016.07.043] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2016] [Revised: 07/14/2016] [Accepted: 07/16/2016] [Indexed: 11/15/2022]
Abstract
The impact of viscous friction on eluent temperature and column efficiency in liquid chromatography is of renewed interest as the need for pressures exceeding 1000bar to use with columns packed with sub-2μm particles has grown. One way the development of axial and radial temperature gradients that arise due to viscous friction can be affected is by the thermal environment the column is placed in. In this study, a new column oven integrated into an ultrahigh pressure liquid chromatograph that enables both still-air and forced-air operating modes is investigated to find the magnitude of the effect of the axial thermal gradient that forms in 2.1×100mm columns packed with sub-2μm particles in these modes. Temperature increases of nearly 30K were observed when the generated power of the column exceeded 25W/m. The impact of the heating due to viscous friction on the repeatability of peak capacity, elution time, and peak area ratio to an internal standard for a gradient UHPLC-MS/MS method to analyze neurotransmitters was found to be limited. This result indicates that high speed UHPLC-MS/MS gradient methods under conditions of high viscous friction may be possible without the negative effects typically observed with isocratic separations under similar conditions.
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Affiliation(s)
- James P Grinias
- Department of Chemistry, University of Michigan, Ann Arbor, MI 48109, United States
| | - Jenny-Marie T Wong
- Department of Chemistry, University of Michigan, Ann Arbor, MI 48109, United States
| | - Robert T Kennedy
- Department of Chemistry, University of Michigan, Ann Arbor, MI 48109, United States; Department of Pharmacology, University of Michigan, Ann Arbor, MI 48109, United States.
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16
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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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17
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Tanaka N, McCalley DV. Core–Shell, Ultrasmall Particles, Monoliths, and Other Support Materials in High-Performance Liquid Chromatography. Anal Chem 2015; 88:279-98. [DOI: 10.1021/acs.analchem.5b04093] [Citation(s) in RCA: 119] [Impact Index Per Article: 13.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Affiliation(s)
| | - David V. McCalley
- Centre for Research in Biosciences, University of the West of England, Frenchay, Bristol BS16 1QY, U.K
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18
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Fekete S, Veuthey JL, Guillarme D. Comparison of the most recent chromatographic approaches applied for fast and high resolution separations: Theory and practice. J Chromatogr A 2015; 1408:1-14. [DOI: 10.1016/j.chroma.2015.07.014] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2015] [Revised: 06/30/2015] [Accepted: 07/03/2015] [Indexed: 10/23/2022]
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19
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Estimation of pressure-, temperature- and frictional heating-related effects on proteins’ retention under ultra-high-pressure liquid chromatographic conditions. J Chromatogr A 2015; 1393:73-80. [DOI: 10.1016/j.chroma.2015.03.023] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2015] [Revised: 02/17/2015] [Accepted: 03/10/2015] [Indexed: 11/19/2022]
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20
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Makarov AA, Schafer WA, Helmy R. Use of pressure in reversed-phase liquid chromatography to study protein conformational changes by differential deuterium exchange. Anal Chem 2015; 87:2396-402. [PMID: 25620238 DOI: 10.1021/ac5043494] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The market of protein therapeutics is exploding, and characterization methods for proteins are being further developed to understand and explore conformational structures with regards to function and activity. There are several spectroscopic techniques that allow for analyzing protein secondary structure in solution. However, a majority of these techniques need to use purified protein, concentrated enough in the solution to produce a relevant spectrum. In this study, we describe a novel approach which uses ultrahigh pressure liquid chromatography (UHPLC) coupled with mass-spectrometry (MS) to explore compressibility of the secondary structure of proteins under increasing pressure detected by hydrogen-deuterium exchange (HDX). Several model proteins were used for these studies. The studies were conducted with UHPLC in isocratic mode at constant flow rate and temperature. The pressure was modified by a backpressure regulator up to about 1200 bar. It was found that the increase of retention factors upon pressure increase, at constant flow rate and temperature, was based on reduction of the proteins' molecular molar volume. The change in the proteins' molecular molar volume was caused by changes in protein folding, as was revealed by differential deuterium exchange. The degree of protein folding under certain UHPLC conditions can be controlled by pressure, at constant temperature and flow rate. By modifying pressure during UHPLC separation, it was possible to achieve changes in protein folding, which were manifested as changes in the number of labile protons exchanged to deuterons, or vice versa. Moreover, it was demonstrated with bovine insulin that a small difference in the number of protons exchanged to deuterons (based on protein folding under pressure) could be observed between batches obtained from different sources. The use of HDX during UHPLC separation allowed one to examine protein folding by pressure at constant flow rate and temperature in a mixture of sample solution with minimal amounts of sample used for analysis.
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Affiliation(s)
- Alexey A Makarov
- Department of Process and Analytical Chemistry, Merck Research Laboratories , 126 East Lincoln Ave., Rahway, New Jersey 07065, United States
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21
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Grinias JP, Keil DS, Jorgenson JW. Observation of enhanced heat dissipation in columns packed with superficially porous particles. J Chromatogr A 2014; 1371:261-4. [DOI: 10.1016/j.chroma.2014.10.075] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2014] [Revised: 09/29/2014] [Accepted: 10/24/2014] [Indexed: 10/24/2022]
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