1
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Fekete S, Lauber M, Xu M. Considering the selectivity of pore size gradient size exclusion chromatography columns. J Chromatogr A 2024; 1718:464726. [PMID: 38354505 DOI: 10.1016/j.chroma.2024.464726] [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: 12/12/2023] [Revised: 01/25/2024] [Accepted: 02/07/2024] [Indexed: 02/16/2024]
Abstract
One of the most significant performance determining variables of a size exclusion column is the pore size of its packing material. This is most definitely the case for assigning the suitability of a given column for differently sized analytes. As technologies for particle and column manufacturing continue to advance, it is worth contemplating the value of more finely controlled manipulation of this parameter. The change in a packing material's pores across the length of a size exclusion column was thus explored. A change in average pore diameter and pore size distribution was studied by means of theoretical modeling. These parameters were investigated for independent and combinatorial effects. From our predictions, versus tandem column chromatography, a gradient column apparatus does not yield sizable increases in monomer to dimer selectivity of any given critical pair. Instead, our modeling suggests it can yield more universally effective separations of multiple pairs of species at once, as is sometimes necessary when analyzing the high molecular weight components of highly aggregated drug substances.
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Affiliation(s)
- Szabolcs Fekete
- Waters Corporation, located in CMU-Rue Michel Servet 1, 1211 Geneva 4, Switzerland.
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2
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Gong X, Chen W, Zhang K, Li T, Song Q. Serially coupled column liquid chromatography: An alternative separation tool. J Chromatogr A 2023; 1706:464278. [PMID: 37572536 DOI: 10.1016/j.chroma.2023.464278] [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: 05/30/2023] [Revised: 07/20/2023] [Accepted: 08/02/2023] [Indexed: 08/14/2023]
Abstract
Despite the rapid development of liquid chromatography (LC) in recent decades, it remains a challenge to achieve the desired chromatographic separation of complex matrices using a single column. Multi-column LC techniques, particularly serially coupled column LC (SCC-LC), have emerged as a promising solution to overcome this challenge. While more attention has been focused on heart-cutting or comprehensive two-dimensional LC, reviews specifically focusing on SCC-LC, which offers advantages in terms of precision and facile instrumentation, are scarce. Here, our concerns are devoted to the progress summary regarding the instrumentation and applications of SCC-LC. Emphasis is placed on column selection aiming to enlarge peak capacity, selectivity, or both through the optimization of combination types (e.g. RPLC-RPLC, -RPLC-HILIC, and achiral-chiral LC), connection devices (e.g. zero dead volume connector, tubing, and T-type connector), elution program (i.e. isocratic or gradient) and detectors (e.g. mass spectrometer, ultraviolet detector, and fluorescence detector). The application of SCC-LC in pharmaceutical, biological, environmental, and food fields is also reviewed, and future perspectives and potential directions for SCC-LC are discussed. We envision that the review can give meaningful information to analytical scientists when facing heavy chromatographic separation tasks for complicated matrices.
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Affiliation(s)
- Xingcheng Gong
- School of Chinese Materia Medica, Beijing University of Chinese Medicine, Beijing 102488, China
| | - Wei Chen
- School of Chinese Materia Medica, Beijing University of Chinese Medicine, Beijing 102488, China
| | - Ke Zhang
- School of Chinese Materia Medica, Beijing University of Chinese Medicine, Beijing 102488, China
| | - Ting Li
- School of Chinese Materia Medica, Beijing University of Chinese Medicine, Beijing 102488, China
| | - Qingqing Song
- School of Chinese Materia Medica, Beijing University of Chinese Medicine, Beijing 102488, China.
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3
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Fekete S, Lauber M. Studying the possibilities of dual stationary phase gradients to explore alternative selectivities in liquid chromatography. J Chromatogr A 2022; 1681:463492. [PMID: 36116368 DOI: 10.1016/j.chroma.2022.463492] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2022] [Revised: 09/05/2022] [Accepted: 09/07/2022] [Indexed: 11/25/2022]
Abstract
Previous studies on stationary phase gradients have inspired a new phase of theoretical work and an expansion of the concept to include multiple retention mechanisms. The theoretical work presented here corroborates previous reports that a stationary phase gradient can produce selectivity in a separation as effectively as careful adjustments to a mobile phase gradient program, especially when such column is operated in mobile phase gradient elution mode. In reality, no column is singularly based on one type of interaction mechanism, and many columns are nowadays designed to solicit multiple solute to stationary phase interactions. These mixed-mode columns inspired us to give more careful consideration to the idea of dual stationary phase gradients. With the theory applied here, it is suggested that the modulation of two unique interaction mechanisms across a chromatographic column has the potential to open up previously unseen selectivities. With the increasing prevalence of mixed-mode columns, we believe there will be ample opportunity to explore these new concepts in experimental work.
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Affiliation(s)
- Szabolcs Fekete
- Waters Corporation, located in CMU-Rue Michel Servet 1, 1211 Geneva 4, Switzerland.
| | - Matthew Lauber
- Waters Corporation, 34 Maple Street, Milford, MA 01757, United States
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4
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Haidar Ahmad IA, Kiffer A, Barrientos RC, Losacco GL, Singh A, Shchurik V, Wang H, Mangion I, Regalado EL. In Silico Method Development of Achiral and Chiral Tandem Column Reversed-phase Liquid Chromatography for Multicomponent Pharmaceutical Mixtures. Anal Chem 2022; 94:4065-4071. [PMID: 35199987 DOI: 10.1021/acs.analchem.1c05551] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Tandem column liquid chromatography (LC) is a convenient, cost-effective approach to resolve multicomponent mixtures by serially coupling columns on readily available one-dimensional separation systems without specialized user training. Yet, adoption of this technique remains limited, mainly due to the difficulty in identifying optimal selectivity out of many possible tandem column combinations. At this point, method development and optimization require laborious "hit-or-miss" experimentation and "blind" screening when investigating different column selectivity without standard analytes. As a result, many chromatography practitioners end up combining two columns of similar selectivity, limiting the scope and potential of tandem column LC as a mainstay for industrial applications. To circumvent this challenge, we herein introduce a straightforward in silico multifactorial approach as a framework to expediently map the separation landscape across multiple tandem columns (achiral and chiral) and eluent combinations (isocratic and gradient elution) under reversed-phase LC conditions. Retention models were built using commercially available LC simulator software showcasing less than 2% difference between experimental and simulated retention times for analytes of interest in multicomponent pharmaceutical mixtures (e.g., metabolites and cyclic peptides).
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Affiliation(s)
- Imad A Haidar Ahmad
- Analytical Research and Development, MRL, Merck & Co., Inc., Rahway, New Jersey 07065, United States
| | - Alaina Kiffer
- Analytical Research and Development, MRL, Merck & Co., Inc., Rahway, New Jersey 07065, United States
| | - Rodell C Barrientos
- Analytical Research and Development, MRL, Merck & Co., Inc., Rahway, New Jersey 07065, United States
| | - Gioacchino Luca Losacco
- Analytical Research and Development, MRL, Merck & Co., Inc., Rahway, New Jersey 07065, United States
| | - Andrew Singh
- Analytical Research and Development, MRL, Merck & Co., Inc., Rahway, New Jersey 07065, United States
| | - Vladimir Shchurik
- Analytical Research and Development, MRL, Merck & Co., Inc., Rahway, New Jersey 07065, United States
| | - Heather Wang
- Analytical Research and Development, MRL, Merck & Co., Inc., Rahway, New Jersey 07065, United States
| | - Ian Mangion
- Analytical Research and Development, MRL, Merck & Co., Inc., Rahway, New Jersey 07065, United States
| | - Erik L Regalado
- Analytical Research and Development, MRL, Merck & Co., Inc., Rahway, New Jersey 07065, United States
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5
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Are Two Liquid Chromatography Columns in Tandem Better Than One?: Answers from the Hydrophobic Subtraction Model. J Chromatogr A 2022; 1668:462890. [DOI: 10.1016/j.chroma.2022.462890] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2021] [Revised: 02/03/2022] [Accepted: 02/08/2022] [Indexed: 11/19/2022]
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6
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Stationary-phase optimized selectivity in supercritical fluid chromatography using a customized Phase OPtimized Liquid Chromatography kit: comparison of different prediction approaches. Anal Bioanal Chem 2020; 412:6553-6565. [DOI: 10.1007/s00216-020-02739-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2019] [Revised: 05/19/2020] [Accepted: 05/25/2020] [Indexed: 10/24/2022]
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7
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Hegade RS, Chen K, Boon JP, Hellings M, Wicht K, Lynen F. Development of an achiral-chiral 2-dimensional heart-cutting platform for enhanced pharmaceutical impurity analysis. J Chromatogr A 2020; 1628:461425. [DOI: 10.1016/j.chroma.2020.461425] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2020] [Revised: 07/19/2020] [Accepted: 07/21/2020] [Indexed: 10/23/2022]
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8
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Chiral stationary phase optimized selectivity supercritical fluid chromatography: A strategy for the separation of mixtures of chiral isomers. J Chromatogr A 2019; 1586:116-127. [DOI: 10.1016/j.chroma.2018.12.008] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2018] [Revised: 11/22/2018] [Accepted: 12/07/2018] [Indexed: 01/13/2023]
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9
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Cain CN, Forzano AV, Rutan SC, Collinson MM. Destructive stationary phase gradients for reversed-phase/hydrophilic interaction liquid chromatography. J Chromatogr A 2018; 1570:82-90. [DOI: 10.1016/j.chroma.2018.07.073] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2018] [Revised: 07/24/2018] [Accepted: 07/26/2018] [Indexed: 02/05/2023]
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10
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Alvarez-Segura T, Camacho-Molinero C, Torres-Lapasió JR, García-Alvarez-Coque MC. Analysis of amino acids using serially coupled columns. J Sep Sci 2017; 40:2741-2751. [PMID: 28520236 DOI: 10.1002/jssc.201700334] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2017] [Revised: 05/05/2017] [Accepted: 05/08/2017] [Indexed: 11/10/2022]
Abstract
Single conventional columns in reversed-phase liquid chromatography are insufficient for analysing the isoindoles of primary amino acids due to their limited functionality. An interesting possibility for increasing the separation power is the combination of several columns of different nature, where the length is modified by coupling small segments. This approach may require a considerable investment to have multiple lengths for each stationary phase. However, the combination of only two columns of fixed length can be enough to resolve satisfactorily relatively complex mixtures, provided that an optimised gradient program is applied. In this work, a mixture of 19 primary amino acid isoindoles found in proteins was analysed. Four stationary phases were assayed: C18, pentafluorophenyl-C18, C4 and cyano. The mixture of isoindoles was successfully resolved in practical times using a pentafluorophenyl-C18 column coupled to a C4 column, in spite of the extremely poor performance obtained when each column is used isolatedly, independently of the length. The extreme diversity in the polarities of the isoindoles and the need of extrapolating the retention behaviour in certain regions of the solvent content domain makes the modelling of the retention behaviour of the isoindoles particularly difficult. Nevertheless, the predicted optimal separations were very satisfactory.
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11
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Stationary phase modulation in liquid chromatography through the serial coupling of columns: A review. Anal Chim Acta 2016; 923:1-23. [DOI: 10.1016/j.aca.2016.03.040] [Citation(s) in RCA: 50] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2015] [Revised: 03/17/2016] [Accepted: 03/21/2016] [Indexed: 01/22/2023]
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12
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Dewoolkar VC, Jeong LN, Cook DW, Ashraf KM, Rutan SC, Collinson MM. Amine Gradient Stationary Phases on In-House Built Monolithic Columns for Liquid Chromatography. Anal Chem 2016; 88:5941-9. [DOI: 10.1021/acs.analchem.6b00895] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Affiliation(s)
- Veeren C. Dewoolkar
- Department of Chemistry, Virginia Commonwealth University, Richmond, Virginia 23284-2006, United States
| | - Lena N. Jeong
- Department of Chemistry, Virginia Commonwealth University, Richmond, Virginia 23284-2006, United States
| | - Daniel W. Cook
- Department of Chemistry, Virginia Commonwealth University, Richmond, Virginia 23284-2006, United States
| | - Kayesh M. Ashraf
- Department of Chemistry, Virginia Commonwealth University, Richmond, Virginia 23284-2006, United States
| | - Sarah C. Rutan
- Department of Chemistry, Virginia Commonwealth University, Richmond, Virginia 23284-2006, United States
| | - Maryanne M. Collinson
- Department of Chemistry, Virginia Commonwealth University, Richmond, Virginia 23284-2006, United States
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13
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On the inherent data fitting problems encountered in modeling retention behavior of analytes with dual retention mechanism. J Chromatogr A 2015; 1403:81-95. [DOI: 10.1016/j.chroma.2015.05.031] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2015] [Revised: 05/07/2015] [Accepted: 05/15/2015] [Indexed: 11/19/2022]
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14
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Tyteca E, Park SH, Shellie RA, Haddad PR, Desmet G. Computer-assisted multi-segment gradient optimization in ion chromatography. J Chromatogr A 2015; 1381:101-9. [DOI: 10.1016/j.chroma.2014.12.085] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2014] [Revised: 12/23/2014] [Accepted: 12/31/2014] [Indexed: 10/24/2022]
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15
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Delahaye S, Lynen F. Implementing Stationary-Phase Optimized Selectivity in Supercritical Fluid Chromatography. Anal Chem 2014; 86:12220-8. [DOI: 10.1021/ac503313j] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Affiliation(s)
- Sander Delahaye
- Separation Science Group,
Department of Organic and Macromolecular Chemistry, Universiteit Gent, Krijgslaan
281 S4-bis, B-9000 Gent, Belgium
| | - Frédéric Lynen
- Separation Science Group,
Department of Organic and Macromolecular Chemistry, Universiteit Gent, Krijgslaan
281 S4-bis, B-9000 Gent, Belgium
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16
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Tyteca E, Guillarme D, Desmet G. Use of individual retention modeling for gradient optimization in hydrophilic interaction chromatography: separation of nucleobases and nucleosides. J Chromatogr A 2014; 1368:125-31. [PMID: 25441348 DOI: 10.1016/j.chroma.2014.09.065] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2014] [Revised: 09/24/2014] [Accepted: 09/25/2014] [Indexed: 11/15/2022]
Abstract
In this study, the separation of twelve nucleobases and nucleosides was optimized via chromatogram simulation (i.e., prediction of individual retention times and estimation of the peak widths) with the use of an empirical (reversed-phase) non-linear model proposed by Neue and Kuss. Retention time prediction errors of less than 2% were observed for all compounds on different stationary phases. As a single HILIC column could not resolve all peaks, the modeling was extended to coupled-column systems (with different stationary phase chemistries) to increase the separation efficiency and selectivity. The analytical expressions for the gradient retention factor on a coupled column system were derived and accurate retention time predictions were obtained (<2% prediction errors in general). The optimized gradient (predicted by the optimization software) included coupling of an amide and an pentahydroxy functionalized silica stationary phases with a gradient profile from 95 to 85%ACN in 6 min and resulted in almost baseline separation of the twelve nucleobases and nucleosides in less than 7 min. The final separation was obtained in less than 4h of instrument time (including equilibration times) and was fully obtained via computer-based optimization. As such, this study provides an example of a case where individual retention modeling can be used as a way to optimize the gradient conditions in the HILIC mode using a non-linear model such as the Neue and Kuss model.
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Affiliation(s)
- Eva Tyteca
- Vrije Universiteit Brussel, Department of Chemical Engineering, Pleinlaan 2, B-1050 Brussels, Belgium.
| | - Davy Guillarme
- School of Pharmaceutical Sciences, University of Geneva, University of Lausanne, 20, Boulevard d'Yvoy, 1211 Geneva 4, Switzerland
| | - Gert Desmet
- Vrije Universiteit Brussel, Department of Chemical Engineering, Pleinlaan 2, B-1050 Brussels, Belgium
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17
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Tyteca E, Vanderlinden K, Favier M, Clicq D, Cabooter D, Desmet G. Enhanced selectivity and search speed for method development using one-segment-per-component optimization strategies. J Chromatogr A 2014; 1358:145-54. [DOI: 10.1016/j.chroma.2014.06.097] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2014] [Revised: 06/24/2014] [Accepted: 06/29/2014] [Indexed: 10/25/2022]
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18
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Ortiz-Bolsico C, Torres-Lapasió J, García-Alvarez-Coque M. Optimisation of gradient elution with serially-coupled columns. Part I: Single linear gradients. J Chromatogr A 2014; 1350:51-60. [DOI: 10.1016/j.chroma.2014.05.017] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2014] [Revised: 04/29/2014] [Accepted: 05/04/2014] [Indexed: 11/30/2022]
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19
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Simultaneous optimization of mobile phase composition, column nature and length to analyse complex samples using serially coupled columns. J Chromatogr A 2013; 1317:39-48. [DOI: 10.1016/j.chroma.2013.06.035] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2013] [Revised: 05/29/2013] [Accepted: 06/14/2013] [Indexed: 11/20/2022]
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20
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Ortiz-Bolsico C, Torres-Lapasió J, Ruiz-Ángel M, García-Álvarez-Coque M. Comparison of two serially coupled column systems and optimization software in isocratic liquid chromatography for resolving complex mixtures. J Chromatogr A 2013; 1281:94-105. [DOI: 10.1016/j.chroma.2013.01.064] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2012] [Revised: 01/10/2013] [Accepted: 01/11/2013] [Indexed: 10/27/2022]
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21
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Chen K, Lynen F, Szucs R, Hanna-Brown M, Sandra P. Gradient stationary phase optimized selectivity liquid chromatography with conventional columns. Analyst 2013; 138:2914-23. [DOI: 10.1039/c3an36797e] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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22
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Ruta J, Boccard J, Cabooter D, Rudaz S, Desmet G, Veuthey JL, Guillarme D. Method development for pharmaceutics: Some solutions for tuning selectivity in reversed phase and hydrophilic interaction liquid chromatography. J Pharm Biomed Anal 2012; 63:95-105. [DOI: 10.1016/j.jpba.2012.01.019] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2011] [Revised: 01/18/2012] [Accepted: 01/19/2012] [Indexed: 02/02/2023]
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23
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Chen K, Lynen F, De Beer M, Hitzel L, Ferguson P, Hanna-Brown M, Sandra P. Selectivity optimization in green chromatography by gradient stationary phase optimized selectivity liquid chromatography. J Chromatogr A 2010; 1217:7222-30. [DOI: 10.1016/j.chroma.2010.09.029] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2010] [Revised: 08/31/2010] [Accepted: 09/08/2010] [Indexed: 11/29/2022]
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24
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De Beer M, Lynen F, Chen K, Ferguson P, Hanna-Brown M, Sandra P. Stationary-Phase Optimized Selectivity Liquid Chromatography: Development of a Linear Gradient Prediction Algorithm. Anal Chem 2010; 82:1733-43. [DOI: 10.1021/ac902287v] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Maarten De Beer
- Pfizer Analytical Research Centre, Ghent University, Krijgslaan 281-S4 Bis, B-9000 Ghent, Belgium, Research Analytics, Pfizer Global R & D, Ramsgate Road, Sandwich, Kent CT13 9NJ, U.K., and Analytical R&D, Pfizer Global R & D, Ramsgate Road, Sandwich, Kent CT13 9NJ, U.K
| | - Fréderic Lynen
- Pfizer Analytical Research Centre, Ghent University, Krijgslaan 281-S4 Bis, B-9000 Ghent, Belgium, Research Analytics, Pfizer Global R & D, Ramsgate Road, Sandwich, Kent CT13 9NJ, U.K., and Analytical R&D, Pfizer Global R & D, Ramsgate Road, Sandwich, Kent CT13 9NJ, U.K
| | - Kai Chen
- Pfizer Analytical Research Centre, Ghent University, Krijgslaan 281-S4 Bis, B-9000 Ghent, Belgium, Research Analytics, Pfizer Global R & D, Ramsgate Road, Sandwich, Kent CT13 9NJ, U.K., and Analytical R&D, Pfizer Global R & D, Ramsgate Road, Sandwich, Kent CT13 9NJ, U.K
| | - Paul Ferguson
- Pfizer Analytical Research Centre, Ghent University, Krijgslaan 281-S4 Bis, B-9000 Ghent, Belgium, Research Analytics, Pfizer Global R & D, Ramsgate Road, Sandwich, Kent CT13 9NJ, U.K., and Analytical R&D, Pfizer Global R & D, Ramsgate Road, Sandwich, Kent CT13 9NJ, U.K
| | - Melissa Hanna-Brown
- Pfizer Analytical Research Centre, Ghent University, Krijgslaan 281-S4 Bis, B-9000 Ghent, Belgium, Research Analytics, Pfizer Global R & D, Ramsgate Road, Sandwich, Kent CT13 9NJ, U.K., and Analytical R&D, Pfizer Global R & D, Ramsgate Road, Sandwich, Kent CT13 9NJ, U.K
| | - Pat Sandra
- Pfizer Analytical Research Centre, Ghent University, Krijgslaan 281-S4 Bis, B-9000 Ghent, Belgium, Research Analytics, Pfizer Global R & D, Ramsgate Road, Sandwich, Kent CT13 9NJ, U.K., and Analytical R&D, Pfizer Global R & D, Ramsgate Road, Sandwich, Kent CT13 9NJ, U.K
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25
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Zedda M, Tuerk J, Teutenberg T, Peil S, Schmidt T. A strategy for the systematic development of a liquid chromatographic mass spectrometric screening method for polymer electrolyte membrane degradation products using isocratic and gradient phase optimized liquid chromatography. J Chromatogr A 2009; 1216:8910-7. [DOI: 10.1016/j.chroma.2009.10.052] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2009] [Revised: 10/14/2009] [Accepted: 10/16/2009] [Indexed: 10/20/2022]
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