1
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Bui QD, Deschrijver T, Noten B, Verluyten W, Vervoort N, Eeltink S. Optimization of elution conditions and comparison of emerging biocompatible columns on the resolving power and detection sensitivity of oligonucleotides by ion-pairing reversed-phase liquid chromatography mass spectrometry. J Chromatogr A 2024; 1720:464793. [PMID: 38484639 DOI: 10.1016/j.chroma.2024.464793] [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: 01/18/2024] [Revised: 02/27/2024] [Accepted: 03/04/2024] [Indexed: 04/02/2024]
Abstract
A generic performance comparison strategy has been developed to evaluate the impact of mobile-phase additives (ion-pairing agent / counter ion systems), distinct stationary phases on resulting resolving power, and MS detectability of oligonucleotides and their critical impurities in gradient IP-RPLC. Stationary-phase considerations included particle type (core-shell vs. fully porous particles), particle diameter, and pore size. Separations were carried out at 60°C to optimize mass transfer (C-term). The incorporation of an active column preheater mitigated thermal mismatches, leading to narrower peaks and overcoming peak splitting. Acetonitrile as organic modifier outweighed methanol in terms of peak-capacity generation and yielded a 30% lower back pressure. Performance screening experiments were conducted varying ion-pairing agents and counter ions, while adjusting gradient span achieved an equivalent effective retention window. Hexafluoromethylisopropanol yielded superior chromatographic resolution, whereas hexafluoroisopropanol yielded significantly higher MS detection sensitivity. The 1.7 µm core-shell particle columns with 100 Å pores provided maximum resolving power for small (15-35 mers) oligonucleotides. Sub-min analysis for 15-35 polyT ladders was achieved operating a 50 mm long column at the kinetic performance limits. High-resolution separations between a 21-mer modified RNA sequence oligonucleotides and its related (shortmer and phosphodiester) impurities and complementary strand were obtained using a coupled column set-up with a total length of 450 mm.
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Affiliation(s)
- Quang-Dong Bui
- Vrije Universiteit Brussel (VUB), Department of Chemical Engineering, Brussels, Belgium
| | - Tiny Deschrijver
- Janssen Pharmaceutica, Process Analytical Research - Chemical Process Research and Development, Beerse, Belgium
| | - Bart Noten
- Janssen Pharmaceutica, Process Analytical Research - Chemical Process Research and Development, Beerse, Belgium
| | - Willy Verluyten
- Janssen Pharmaceutica, Analytical Development, Beerse, Belgium
| | - Nico Vervoort
- Janssen Pharmaceutica, Process Analytical Research - Chemical Process Research and Development, Beerse, Belgium
| | - Sebastiaan Eeltink
- Vrije Universiteit Brussel (VUB), Department of Chemical Engineering, Brussels, Belgium.
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2
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Allwright M, Guennewig B, Hoffmann AE, Rohleder C, Jieu B, Chung LH, Jiang YC, Lemos Wimmer BF, Qi Y, Don AS, Leweke FM, Couttas TA. ReTimeML: a retention time predictor that supports the LC-MS/MS analysis of sphingolipids. Sci Rep 2024; 14:4375. [PMID: 38388524 PMCID: PMC10883992 DOI: 10.1038/s41598-024-53860-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2023] [Accepted: 02/06/2024] [Indexed: 02/24/2024] Open
Abstract
The analysis of ceramide (Cer) and sphingomyelin (SM) lipid species using liquid chromatography-tandem mass spectrometry (LC-MS/MS) continues to present challenges as their precursor mass and fragmentation can correspond to multiple molecular arrangements. To address this constraint, we developed ReTimeML, a freeware that automates the expected retention times (RTs) for Cer and SM lipid profiles from complex chromatograms. ReTimeML works on the principle that LC-MS/MS experiments have pre-determined RTs from internal standards, calibrators or quality controls used throughout the analysis. Employed as reference RTs, ReTimeML subsequently extrapolates the RTs of unknowns using its machine-learned regression library of mass-to-charge (m/z) versus RT profiles, which does not require model retraining for adaptability on different LC-MS/MS pipelines. We validated ReTimeML RT estimations for various Cer and SM structures across different biologicals, tissues and LC-MS/MS setups, exhibiting a mean variance between 0.23 and 2.43% compared to user annotations. ReTimeML also aided the disambiguation of SM identities from isobar distributions in paired serum-cerebrospinal fluid from healthy volunteers, allowing us to identify a series of non-canonical SMs associated between the two biofluids comprised of a polyunsaturated structure that confers increased stability against catabolic clearance.
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Affiliation(s)
- Michael Allwright
- ForeFront, Brain and Mind Centre, The University of Sydney, Sydney, Australia
| | - Boris Guennewig
- ForeFront, Brain and Mind Centre, The University of Sydney, Sydney, Australia
| | - Anna E Hoffmann
- Translational Research Collective, Brain and Mind Centre, The University of Sydney, Sydney, NSW, 2006, Australia
- Endosane Pharmaceuticals GmbH, Berlin, Germany
| | - Cathrin Rohleder
- Translational Research Collective, Brain and Mind Centre, The University of Sydney, Sydney, NSW, 2006, Australia
- Endosane Pharmaceuticals GmbH, Berlin, Germany
- Department of Psychiatry and Psychotherapy, Central Institute of Mental Health, Medical Faculty Mannheim, Heidelberg University, Mannheim, Germany
| | - Beverly Jieu
- Translational Research Collective, Brain and Mind Centre, The University of Sydney, Sydney, NSW, 2006, Australia
| | - Long H Chung
- Centenary Institute, The University of Sydney, Sydney, Australia
| | - Yingxin C Jiang
- Centenary Institute, The University of Sydney, Sydney, Australia
| | - Bruno F Lemos Wimmer
- Translational Research Collective, Brain and Mind Centre, The University of Sydney, Sydney, NSW, 2006, Australia
| | - Yanfei Qi
- Centenary Institute, The University of Sydney, Sydney, Australia
| | - Anthony S Don
- School of Medical Sciences, Faculty of Medicine and Health, The University of Sydney, Sydney, Australia
| | - F Markus Leweke
- Translational Research Collective, Brain and Mind Centre, The University of Sydney, Sydney, NSW, 2006, Australia
- Endosane Pharmaceuticals GmbH, Berlin, Germany
- Department of Psychiatry and Psychotherapy, Central Institute of Mental Health, Medical Faculty Mannheim, Heidelberg University, Mannheim, Germany
| | - Timothy A Couttas
- Translational Research Collective, Brain and Mind Centre, The University of Sydney, Sydney, NSW, 2006, Australia.
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3
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Recycling gradient-elution liquid chromatography for the analysis of chemical-composition distributions of polymers. J Chromatogr A 2022; 1679:463386. [DOI: 10.1016/j.chroma.2022.463386] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2022] [Revised: 07/13/2022] [Accepted: 07/27/2022] [Indexed: 11/18/2022]
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4
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Gritti F, David M, Brothy P, Lewis MR. Model of retention time and density of gradient peak capacity for improved LC-MS method optimization: Application to metabolomics. Anal Chim Acta 2022; 1197:339492. [DOI: 10.1016/j.aca.2022.339492] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2021] [Revised: 12/20/2021] [Accepted: 01/11/2022] [Indexed: 11/28/2022]
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5
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A comparison of 2 micron inner diameter open tubular column liquid chromatography with pressure-driven isocratic, slip-flow, and electrochromatographic modes of operation: a theoretical study. J Chromatogr A 2020; 1638:461818. [PMID: 33516049 DOI: 10.1016/j.chroma.2020.461818] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2020] [Revised: 12/12/2020] [Accepted: 12/13/2020] [Indexed: 11/22/2022]
Abstract
Modifications to the flow profile used in open tube capillary liquid chromatography (OT-CLC) include using slip-flow walls and using electroosmosis as a fluid pump as practiced in electrochromatography. These modifications are implemented experimentally by changing the capillary surface and solvent conditions which results in the change of boundary conditions at the capillary wall. In this paper we employ a theory-based study and compare the zone broadening of simple solutes using parabolic flow from a liquid pump, slip-flow from a highly hydrophobic inner surface with water eluent, and electroosmosis for the conditions of pure water and dilute salt utilizing 2 µm inner diameter OT capillaries. In general, the two types of flow other than parabolic exhibit thin zones in the early part of the chromatogram, consistent with previous studies of slip-flow and electroosmotic flow used in electrochromatography. Electrochromatography is shown to yield higher efficiency and less zone broadening than parabolic and slip-flow conditions used in this study. Nonetheless, it is found that the zone standard deviations are shown to be similar for these flow profiles as is the number of plates for these different flow profiles under the conditions utilized here. It is revealed that these modifications do not warrant the effort to maintain the special solvent conditions when compared to gradient elution OT-CLC, which gives a nearly constant peak width throughout the chromatogram, is easiest to implement, and is the method of choice for complex analysis.
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6
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den Uijl MJ, Schoenmakers PJ, Pirok BWJ, van Bommel MR. Recent applications of retention modelling in liquid chromatography. J Sep Sci 2020; 44:88-114. [PMID: 33058527 PMCID: PMC7821232 DOI: 10.1002/jssc.202000905] [Citation(s) in RCA: 45] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2020] [Revised: 10/02/2020] [Accepted: 10/12/2020] [Indexed: 11/18/2022]
Abstract
Recent applications of retention modelling in liquid chromatography (2015–2020) are comprehensively reviewed. The fundamentals of the field, which date back much longer, are summarized. Retention modeling is used in retention‐mechanism studies, for determining physical parameters, such as lipophilicity, and for various more‐practical purposes, including method development and optimization, method transfer, and stationary‐phase characterization and comparison. The review focusses on the effects of mobile‐phase composition on retention, but other variables and novel models to describe their effects are also considered. The five most‐common models are addressed in detail, i.e. the log‐linear (linear‐solvent‐strength) model, the quadratic model, the log–log (adsorption) model, the mixed‐mode model, and the Neue–Kuss model. Isocratic and gradient‐elution methods are considered for determining model parameters and the evaluation and validation of fitted models is discussed. Strategies in which retention models are applied for developing and optimizing one‐ and two‐dimensional liquid chromatographic separations are discussed. The review culminates in some overall conclusions and several concrete recommendations.
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Affiliation(s)
- Mimi J den Uijl
- Analytical Chemistry Group, van 't Hoff Institute for Molecular Sciences, University of Amsterdam, Amsterdam, The Netherlands.,Centre for Analytical Sciences Amsterdam (CASA), Amsterdam, The Netherlands
| | - Peter J Schoenmakers
- Analytical Chemistry Group, van 't Hoff Institute for Molecular Sciences, University of Amsterdam, Amsterdam, The Netherlands.,Centre for Analytical Sciences Amsterdam (CASA), Amsterdam, The Netherlands
| | - Bob W J Pirok
- Analytical Chemistry Group, van 't Hoff Institute for Molecular Sciences, University of Amsterdam, Amsterdam, The Netherlands.,Centre for Analytical Sciences Amsterdam (CASA), Amsterdam, The Netherlands
| | - Maarten R van Bommel
- Analytical Chemistry Group, van 't Hoff Institute for Molecular Sciences, University of Amsterdam, Amsterdam, The Netherlands.,Centre for Analytical Sciences Amsterdam (CASA), Amsterdam, The Netherlands.,University of Amsterdam, Faculty of Humanities, Conservation and Restoration of Cultural Heritage, Amsterdam, The Netherlands
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7
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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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8
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Hao W, Wang K, Yue B, Chen Q, Huang Y, Yu J, Li D. Peak compression in linear gradient elution liquid chromatography. J Chromatogr A 2020; 1619:460908. [DOI: 10.1016/j.chroma.2020.460908] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2019] [Revised: 01/06/2020] [Accepted: 01/20/2020] [Indexed: 11/27/2022]
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9
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Baeza-Baeza J, García-Alvarez-Coque M. Peak dispersion in gradient elution: An insight based on the plate model. J Chromatogr A 2020; 1613:460670. [DOI: 10.1016/j.chroma.2019.460670] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2019] [Revised: 10/31/2019] [Accepted: 11/02/2019] [Indexed: 10/25/2022]
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10
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Cain CN, Forzano AV, Rutan SC, Collinson MM. Experimental- and simulation-based investigations of coupling a mobile phase gradient with a continuous stationary phase gradient. J Chromatogr A 2019; 1602:237-245. [PMID: 31147155 DOI: 10.1016/j.chroma.2019.05.033] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2019] [Revised: 05/12/2019] [Accepted: 05/18/2019] [Indexed: 12/23/2022]
Abstract
This work seeks to explore and understand the effects of column orientation and degree of modification of continuous stationary phase gradient columns under a mobile phase gradient using both simulations and experiments. Peak parameters such as retention times, peak widths and resolution are obtained for five phenolic compounds on a C18-silica gradient stationary phase. Simulations show that peak widths for the solutes are dependent upon the fractional composition of C18 and orientation of the stationary phase gradient when coupled to a mobile phase gradient. Also, when compared to a simulated uniform mixed-mode column, peak widths reach a minimum on the gradient column with a coverage higher than 50% C18 where the column is oriented to have the C18 dense region at the end. Experimentally, continuous stationary phase gradients were fabricated to have a total C18 composition of 78% of the original uniform column with an exponential profile using a previously described destructive controlled rate infusion method. Under gradient mobile phase conditions, experimental retention times for the gradient column showed a significant increase compared to the original 100% C18 column. Simulations with a similar C18 composition, however, predicted decreased retention times from the original C18 column. A statistical increase in the retention time of protocatechuic acid and decrease in the peak width of tyrosol, caffeic acid, and coumaric acid were noted when the gradient column was oriented to have the C18 dense region located near the detector. Collectively, combining gradients in both the mobile and stationary phases can yield interesting neighboring ligand effects and peak broadening/focusing effects.
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Affiliation(s)
- Caitlin N Cain
- Department of Chemistry, Virginia Commonwealth University, 1001 W. Main St., Richmond, VA, 23284-2006, USA
| | - Anna V Forzano
- Department of Chemistry, Virginia Commonwealth University, 1001 W. Main St., Richmond, VA, 23284-2006, USA
| | - Sarah C Rutan
- Department of Chemistry, Virginia Commonwealth University, 1001 W. Main St., Richmond, VA, 23284-2006, USA.
| | - Maryanne M Collinson
- Department of Chemistry, Virginia Commonwealth University, 1001 W. Main St., Richmond, VA, 23284-2006, USA.
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11
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Gritti F, Belanger J, Izzo G, Leveille W. On the performance of conically shaped columns: Theory and practice. J Chromatogr A 2019; 1593:34-46. [PMID: 30704777 DOI: 10.1016/j.chroma.2019.01.055] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2018] [Revised: 01/13/2019] [Accepted: 01/19/2019] [Indexed: 11/28/2022]
Abstract
The chromatographic performance (speed, efficiency, and gradient peak capacity for the same analysis time) of conical columns are investigated from fundamental and experimental viewpoints. A stainless steel, conically shaped column (2.1 mm i.d/4.2 mm i.d. × 15 cm long, 0.4° opening angle) was prepared in-house and packed with 5 μm XBridge-C18 fully porous particles. Its performance was compared to that of a conventional 3.0 mm × 15 cm cylindrical column packed with the same batch of particles. Both Giddings' theory of non-uniform columns and experiments agree and show that, irrespective of flow direction, the conical column is 15% less efficient than the conventional column. Remarkably, Blumberg's theory of band broadening in gradient elution mode predicts that conical columns may outperform conventional cylindrical columns if the ratio of their outlet i.d. to their inlet i.d. is 0.95 and 0.80 for small molecule and peptide mixtures, respectively. The maximum relative gain is marginal as it does not exceed a few percents. The theory reveals that the flow direction should be from the wide to the narrow end of the conical column in order to deliver the highest peak capacity. In agreement with the theory, the observed losses in absolute peak capacity for the same analysis time are 14.5% (narrow to wide end) and only 11.0% (wide to the narrow end) for small molecules (n-alkanophenones). They are 14.2% (narrow to wide end) and only 8.5% (wide to the narrow end) for peptide samples (bombesin). Additionally, conical columns reduce peak tailing with respect to standard columns. They are suitable column technology for ultra-fast gradient separations as they also minimize sample dispersion through the narrow i.d. outlet frit.
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Affiliation(s)
- Fabrice Gritti
- Waters Corporation, 34 Maple Street, Milford, MA 01757, USA.
| | - Jon Belanger
- Waters Corporation, 34 Maple Street, Milford, MA 01757, USA
| | - Gary Izzo
- Waters Corporation, 34 Maple Street, Milford, MA 01757, USA
| | - Wade Leveille
- Waters Corporation, 34 Maple Street, Milford, MA 01757, USA
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12
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Impact of instrument and column parameters on high-throughput liquid chromatography performance. J Chromatogr A 2017; 1523:215-223. [DOI: 10.1016/j.chroma.2017.07.035] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2017] [Revised: 07/07/2017] [Accepted: 07/10/2017] [Indexed: 12/21/2022]
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13
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Blue LE, Franklin EG, Godinho JM, Grinias JP, Grinias KM, Lunn DB, Moore SM. Recent advances in capillary ultrahigh pressure liquid chromatography. J Chromatogr A 2017; 1523:17-39. [PMID: 28599863 DOI: 10.1016/j.chroma.2017.05.039] [Citation(s) in RCA: 47] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2017] [Revised: 05/12/2017] [Accepted: 05/15/2017] [Indexed: 11/28/2022]
Abstract
In the twenty years since its initial demonstration, capillary ultrahigh pressure liquid chromatography (UHPLC) has proven to be one of most powerful separation techniques for the analysis of complex mixtures. This review focuses on the most recent advances made since 2010 towards increasing the performance of such separations. Improvements in capillary column preparation techniques that have led to columns with unprecedented performance are described. New stationary phases and phase supports that have been reported over the past decade are detailed, with a focus on their use in capillary formats. A discussion on the instrument developments that have been required to ensure that extra-column effects do not diminish the intrinsic efficiency of these columns during analysis is also included. Finally, the impact of these capillary UHPLC topics on the field of proteomics and ways in which capillary UHPLC may continue to be applied to the separation of complex samples are addressed.
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Affiliation(s)
- Laura E Blue
- Process Development, Amgen Inc., Thousand Oaks, CA 91320, USA
| | - Edward G Franklin
- HPLC Research & Development, Restek Corp., Bellefonte, PA 16823, USA
| | - Justin M Godinho
- Department of Chemistry, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
| | - James P Grinias
- Department of Chemistry and Biochemistry, Rowan University, Glassboro, NJ 08028, USA.
| | - Kaitlin M Grinias
- Department of Product Development & Supply, GlaxoSmithKline, King of Prussia, PA 19406, USA
| | - Daniel B Lunn
- Department of Chemistry, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
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Gilar M, McDonald TS, Gritti F. Experimental evaluation of chromatographic performance of capillary and microfluidic columns with linear or curved channels. J Chromatogr A 2016; 1470:76-83. [DOI: 10.1016/j.chroma.2016.10.004] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2016] [Revised: 09/29/2016] [Accepted: 10/05/2016] [Indexed: 11/16/2022]
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15
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Gritti F. Combined solvent- and non-uniform temperature-programmed gradient liquid chromatography. I - A theoretical investigation. J Chromatogr A 2016; 1473:38-47. [PMID: 27814914 DOI: 10.1016/j.chroma.2016.09.026] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2016] [Revised: 08/26/2016] [Accepted: 09/13/2016] [Indexed: 10/21/2022]
Abstract
An new class of gradient liquid chromatography (GLC) is proposed and its performance is analyzed from a theoretical viewpoint. During the course of such gradients, both the solvent strength and the column temperature are simultaneously changed in time and space. The solvent and temperature gradients propagate along the chromatographic column at their own and independent linear velocity. This class of gradient is called combined solvent- and temperature-programmed gradient liquid chromatography (CST-GLC). The general expressions of the retention time, retention factor, and of the temporal peak width of the analytes at elution in CST-GLC are derived for linear solvent strength (LSS) retention models, modified van't Hoff retention behavior, linear and non-distorted solvent gradients, and for linear temperature gradients. In these conditions, the theory predicts that CST-GLC is equivalent to a unique and apparent dynamic solvent gradient. The apparent solvent gradient steepness is the sum of the solvent and temperature steepness. The apparent solvent linear velocity is the reciprocal of the steepness-averaged sum of the reciprocal of the actual solvent and temperature linear velocities. The advantage of CST-GLC over conventional GLC is demonstrated for the resolution of protein digests (peptide mapping) when applying smooth, retained, and linear acetonitrile gradients in combination with a linear temperature gradient (from 20°C to 90°C) using 300μm×150mm capillary columns packed with sub-2 μm particles. The benefit of CST-GLC is demonstrated when the temperature gradient propagates at the same velocity as the chromatographic speed. The experimental proof-of-concept for the realization of temperature ramps propagating at a finite and constant linear velocity is also briefly described.
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Affiliation(s)
- Fabrice Gritti
- Waters Corporation, Instrument/Core Research/Fundamental, Milford, MA 01757, USA.
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16
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Gritti F, Gilar M, Jarrell JA. Quasi-adiabatic vacuum-based column housing for very high-pressure liquid chromatography. J Chromatogr A 2016; 1456:226-34. [DOI: 10.1016/j.chroma.2016.06.029] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2016] [Revised: 06/07/2016] [Accepted: 06/08/2016] [Indexed: 11/27/2022]
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17
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Intrinsic advantages of packed capillaries over narrow-bore columns in very high-pressure gradient liquid chromatography. J Chromatogr A 2016; 1451:107-119. [DOI: 10.1016/j.chroma.2016.05.035] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2016] [Revised: 04/08/2016] [Accepted: 05/08/2016] [Indexed: 11/22/2022]
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