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Rutan SC, Kempen T, Dahlseid T, Kruger Z, Pirok B, Shackman JG, Zhou Y, Wang Q, Stoll DR. Improved hydrophobic subtraction model of reversed-phase liquid chromatography selectivity based on a large dataset with a focus on isomer selectivity. J Chromatogr A 2024; 1731:465127. [PMID: 39053256 DOI: 10.1016/j.chroma.2024.465127] [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: 04/08/2024] [Revised: 06/13/2024] [Accepted: 06/28/2024] [Indexed: 07/27/2024]
Abstract
Reversed-phase (RP) liquid chromatography is an important tool for the characterization of materials and products in the pharmaceutical industry. Method development is still challenging in this application space, particularly when dealing with closely-related compounds. Models of chromatographic selectivity are useful for predicting which columns out of the hundreds that are available are likely to have very similar, or different, selectivity for the application at hand. The hydrophobic subtraction model (HSM1) has been widely employed for this purpose; the column database for this model currently stands at 750 columns. In previous work we explored a refinement of the original HSM1 (HSM2) and found that increasing the size of the dataset used to train the model dramatically reduced the number of gross errors in predictions of selectivity made using the model. In this paper we describe further work in this direction (HSM3), this time based on a much larger solute set (1014 solute/stationary phase combinations) containing selectivities for compounds covering a broader range of physicochemical properties compared to HSM1. The molecular weight range was doubled, and the range of the logarithm of the octanol/water partition coefficients was increased slightly. The number of active pharmaceutical ingredients and related synthetic intermediates and impurities was increased from four to 28, and ten pairs of closely related structures (e.g., geometric and cis-/trans- isomers) were included. The HSM3 model is based on retention measurements for 75 compounds using 13 RP stationary phases and a mobile phase of 40/60 acetonitrile/25 mM ammonium formate buffer at pH 3.2. This data-driven model produced predictions of ln α (chromatographic selectivity using ethylbenzene as the reference compound) with average absolute errors of approximately 0.033, which corresponds to errors in α of about 3 %. In some cases, the prediction of the trans-/cis- selectivities for positional and geometric isomers was relatively accurate, and the driving forces for the observed selectivity could be inferred by examination of the relative magnitudes of the terms in the HSM3 model. For some geometric isomer pairs the interactions mainly responsible for the observed selectivities could not be rationalized due to large uncertainties for particular terms in the model. This suggests that more work is needed in the future to explore other HSM-type models and continue expanding the training dataset in order to continue improving the predictive accuracy of these models. Additionally, we release with this paper a much larger data set (43,329 total retention measurements) at multiple mobile phase compositions, to enable other researchers to pursue their own lines of inquiry related to RP selectivity.
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Affiliation(s)
- Sarah C Rutan
- Department of Chemistry, Virginia Commonwealth University, Box 842006, Richmond, VA 23284-2006, USA
| | - Trevor Kempen
- Department of Chemistry, Gustavus Adolphus College, 800 W. College Ave., St. Peter, MN 56082, USA
| | - Tina Dahlseid
- Department of Chemistry, Gustavus Adolphus College, 800 W. College Ave., St. Peter, MN 56082, USA
| | - Zachary Kruger
- Department of Chemistry, Gustavus Adolphus College, 800 W. College Ave., St. Peter, MN 56082, USA
| | - Bob Pirok
- Department of Chemistry, Gustavus Adolphus College, 800 W. College Ave., St. Peter, MN 56082, USA
| | - Jonathan G Shackman
- Chemical Process Development, Bristol Myers Squibb, 1 Squibb Dr., New Brunswick, NJ 08903, USA
| | - Yiyang Zhou
- Chemical Process Development, Bristol Myers Squibb, 1 Squibb Dr., New Brunswick, NJ 08903, USA
| | - Qinggang Wang
- Chemical Process Development, Bristol Myers Squibb, 1 Squibb Dr., New Brunswick, NJ 08903, USA
| | - Dwight R Stoll
- Department of Chemistry, Gustavus Adolphus College, 800 W. College Ave., St. Peter, MN 56082, USA.
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Zhou Y, Ramirez A, Yuill EM, Wang Q. Mechanistic studies to understand peak tailing due to sulfinic acid- and carboxylic acid-silanophilic interactions in reversed-phase liquid chromatography. J Chromatogr A 2024; 1721:464819. [PMID: 38537485 DOI: 10.1016/j.chroma.2024.464819] [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: 01/08/2024] [Revised: 03/13/2024] [Accepted: 03/14/2024] [Indexed: 04/13/2024]
Abstract
Silanophilic interactions are a primary contributor to peak tailing of acidic pharmaceutical compounds, thus a thorough understanding is especially important for reversed-phase liquid chromatography (RPLC) method development. Herein, a sulfinic acid compound that exhibited severe peak tailing in RPLC with acidic mobile phases was carefully studied. Results indicated that the neutral protonated form of the sulfinic acid is involved in the strong interaction that leads to peak tailing, but that tailing can be mitigated with a blocking effect achieved through use of acetic acid modifier in the mobile phase. Peak tailing was also observed with other structurally-similar sulfinic acids and carboxylic acids but was, in general, less severe with the latter. The Hydrophobic Subtraction Model (HSM) was applied to six commercial C18 columns that exhibited different tailing behaviors for the sulfinic acid compound in attempts to identify key sites of interaction within the stationary phase. A combination of heated acid column wash experiments and density functional theory (DFT) calculations indicate that the differential interactions of the acids with vicinal silanol pairs in the stationary phase play a major role in peak tailing.
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Affiliation(s)
- Yiyang Zhou
- Chemical Process Development, Bristol Myers Squibb Company, 1 Squibb Drive, New Brunswick, NJ 08903, USA.
| | - Antonio Ramirez
- Chemical Process Development, Bristol Myers Squibb Company, 1 Squibb Drive, New Brunswick, NJ 08903, USA
| | - Elizabeth M Yuill
- Chemical Process Development, Bristol Myers Squibb Company, 1 Squibb Drive, New Brunswick, NJ 08903, USA
| | - Qinggang Wang
- Chemical Process Development, Bristol Myers Squibb Company, 1 Squibb Drive, New Brunswick, NJ 08903, USA
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3
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Understanding the retention mechanisms of a reversed-phase/anion exchange/cation-exchange column for the separation of epinephrine and norepinephrine. J Pharm Biomed Anal 2023; 227:115273. [PMID: 36736111 DOI: 10.1016/j.jpba.2023.115273] [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: 10/31/2022] [Revised: 01/24/2023] [Accepted: 01/24/2023] [Indexed: 01/27/2023]
Abstract
In this paper, we investigated the retention mechanisms of a reversed-phase/anion-exchange/cation-exchange column (Acclaim trinity P1, Thermo Fisher Scientific) for the separation of epinephrine (EPI) from norepinephrine (NOE). The impact of the acetonitrile (ACN) content, pH, and salt concentration on the retention of these two catecholamines was studied under an isocratic mode with a mobile phase mixture of ACN and ammonium formate or acetate (pH 3 to pH 5). To better understand the retention mechanisms, several retention models were explored, including linear solvent strength, adsorption, quadratic, and mixed-mode models, using various chemical compounds in addition to EPI and NOE. The quadratic and mixed-mode models were the most appropriate to explain the column retention mechanisms according to the Akaike information criterion (AIC). The research showed the importance of the ACN content on the retention of compounds according to the quadratic model, and satisfactory resolution between EPI and NOE (>1.4) was achieved with 50% ACN content. The most important retention parameters were integrated in the mixed-mode model, namely ACN content, pH, and salt concentration. Using a three-factor Box-Behnken design (BBD), other optimal conditions were obtained to separate EPI and NOE with a resolution Rs > 1.5. The ACN content and salt concentrations of the aqueous part of the mobile phase were the parameters with the greatest impact on the separation performance of the stationary phase for both catecholamines. Finally, a rapid and simple separation of a mixture of EPI, NOE, and tetracaine was obtained using a mobile phase composed of ACN/ammonium formate (pH 4; 10 mM) (60:40, v/v), with a satisfactory resolution (>1.5) between the analyte peaks.
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Sun G, Zhang Z, Yang L, Jiang J, Yao W, Pan L, Chen L, Li C, Liu Z. Optimizing the preparative capacity of two-dimensional liquid chromatography based on analytes retention behaviors. J Chromatogr A 2023; 1690:463786. [PMID: 36641939 DOI: 10.1016/j.chroma.2023.463786] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2022] [Revised: 01/06/2023] [Accepted: 01/07/2023] [Indexed: 01/11/2023]
Abstract
In this work, a solute retention optimization method (SRO) was proposed to exploit the purification potential of two-dimensional liquid chromatography (2D-LC). According to our findings, the complementarity of 2D-LC correlates with some specific impurities. In the two methods used in 2D-LC, the retention order of these impurities and target compound is completely opposite. Taking full advantage of the complementarity is crucial to enhance the saturation capacity (wmax) of 2D-LC by SRO. For the purpose of validating the effectiveness of SRO, a reverse-phase liquid chromatography (RPLC) coupled with hydrophilic interaction chromatography (HILIC) was developed to purify p-chlorobenzoic acid from substituted benzenes. By using the overloading effects of analytes as indicators, the wmax of RPLC × HILIC was determined by the bisection method, and finally defined by the extremely high loading volume of 4.9 mL. A touch-peak separation of impurities and the target compound occurred precisely during the secondary separation. The effectiveness of SRO was also verified by the greater purification efficiency of RPLC × HILIC than that of HILIC × RPLC. Subsequently, a RPLC × RPLC method was developed by SRO to prepare the reference materials of caffeine from tea extracts. Only by an analytical C18 column, 15.6 mg of caffeine with the purity of 98.3% was obtained at once with the recovery up to 82.3%. However, without the aid of SRO, the purity rapidly decreased to 62.0%. Compared to other methods, SRO-based 2D-LC offers certain advantages in terms of purity, recovery, and the purification efficiency, suggesting that it is particularly effective in developing preparative 2D-LC facing complex matrices.
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Affiliation(s)
- Guangying Sun
- College of Chemistry and Chemical Engineering, Huangshan University, Anhui (245041), China.
| | - Zheng Zhang
- College of Chemistry and Chemical Engineering, Huangshan University, Anhui (245041), China
| | - Liying Yang
- College of Chemistry and Chemical Engineering, Huangshan University, Anhui (245041), China
| | - Jianming Jiang
- Huangshan Zhengjie New Materials Co. Ltd., No. 9, Weiyi Road, Shexian Economic Recycling Park, Huangshan City, Anhui Province (245200), China
| | - Wu Yao
- College of Chemistry and Chemical Engineering, Huangshan University, Anhui (245041), China
| | - Le Pan
- College of Chemistry and Chemical Engineering, Huangshan University, Anhui (245041), China
| | - Long Chen
- College of Chemistry and Chemical Engineering, Huangshan University, Anhui (245041), China
| | - Changjiang Li
- College of Chemistry and Chemical Engineering, Huangshan University, Anhui (245041), China.
| | - Zhaosheng Liu
- Tianjin Key Laboratory on Technologies Enabling Development of Clinical Therapeutics and Diagnostics (Theranostics), School of Pharmacy, Tianjin Medical University, Tianjin (300070), China.
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Urban J, Nechvátalová M, Hekerle L. Retention prediction of monoamine neurotransmitters in gradient liquid chromatography. J Sep Sci 2022; 45:3319-3327. [PMID: 35855653 DOI: 10.1002/jssc.202200201] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2022] [Revised: 07/11/2022] [Accepted: 07/16/2022] [Indexed: 11/11/2022]
Abstract
Retention prediction of monoamine neurotransmitters has been compared for the generally applied linear solvent-strength model and quadratic polynomial three-parameter model. The design of experiments protocol has been applied to plan linear gradients within the experimental space with altered gradient time, mobile phase flowrate, and column temperature. Relative prediction errors increased at elevated temperature, which is more significant for the linear solvent-strength model when compared to the polynomial model. On the other hand, the predefined design of experiments space controls the retention time errors, as predictions for LC conditions that are outside of the plan are much less accurate and should be avoided. The final part of the work deals with the effect of extracolumn band dispersion on the peak capacity of linear gradients at various gradient times, mobile phase flowrates, and column temperature. The peak capacity determined for corrected experimental data were consistent with the published results dealing with the optimization of peak capacity in gradient elution. This article is protected by copyright. All rights reserved.
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Affiliation(s)
- Jiří Urban
- Department of Chemistry, Faculty of Science, Masaryk University, Kamenice 5, 625 00 Brno, Czech Republic
| | - Martina Nechvátalová
- Department of Chemistry, Faculty of Science, Masaryk University, Kamenice 5, 625 00 Brno, Czech Republic
| | - Lukáš Hekerle
- Department of Chemistry, Faculty of Science, Masaryk University, Kamenice 5, 625 00 Brno, Czech Republic
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Lima JM, Leme GM, Costa EV, Cass QB. LC-HRMS and acetylcholinesterase affinity assay as a workflow for profiling alkaloids in Annona salzmannii extract. J Chromatogr B Analyt Technol Biomed Life Sci 2021; 1164:122493. [DOI: 10.1016/j.jchromb.2020.122493] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2020] [Revised: 12/02/2020] [Accepted: 12/04/2020] [Indexed: 02/07/2023]
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7
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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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8
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Poole CF, Atapattu SN. Determination of physicochemical properties of small molecules by reversed-phase liquid chromatography. J Chromatogr A 2020; 1626:461427. [DOI: 10.1016/j.chroma.2020.461427] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2020] [Revised: 07/19/2020] [Accepted: 07/22/2020] [Indexed: 02/07/2023]
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9
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Evaluation of the solvation parameter model as a quantitative structure-retention relationship model for gas and liquid chromatography. J Chromatogr A 2020; 1626:461308. [DOI: 10.1016/j.chroma.2020.461308] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2020] [Revised: 06/02/2020] [Accepted: 06/03/2020] [Indexed: 12/14/2022]
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10
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Poole CF. Wayne State University experimental descriptor database for use with the solvation parameter model. J Chromatogr A 2020; 1617:460841. [DOI: 10.1016/j.chroma.2019.460841] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2019] [Revised: 12/26/2019] [Accepted: 12/31/2019] [Indexed: 01/04/2023]
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11
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Poole CF. Gas chromatography system constant database for 52 wall-coated, open-tubular columns covering the temperature range 60–140 °C. J Chromatogr A 2019; 1604:460482. [DOI: 10.1016/j.chroma.2019.460482] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2019] [Revised: 08/21/2019] [Accepted: 08/22/2019] [Indexed: 10/26/2022]
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12
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Reversed-phase liquid chromatography system constant database over an extended mobile phase composition range for 25 siloxane-bonded silica-based columns. J Chromatogr A 2019; 1600:112-126. [DOI: 10.1016/j.chroma.2019.04.027] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2019] [Revised: 04/06/2019] [Accepted: 04/10/2019] [Indexed: 11/23/2022]
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13
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Stable-bond polymeric reversed-phase/weak anion-exchange mixed-mode stationary phases obtained by simultaneous functionalization and crosslinking of a poly(3-mercaptopropyl)methylsiloxane-film on vinyl silica via thiol-ene double click reaction. J Chromatogr A 2019; 1593:110-118. [DOI: 10.1016/j.chroma.2019.01.078] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2018] [Revised: 01/17/2019] [Accepted: 01/31/2019] [Indexed: 02/07/2023]
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14
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Column selection for comprehensive two-dimensional liquid chromatography using the hydrophobic subtraction model. J Chromatogr A 2019; 1589:47-55. [DOI: 10.1016/j.chroma.2018.09.018] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2018] [Revised: 09/05/2018] [Accepted: 09/09/2018] [Indexed: 12/15/2022]
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15
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Poole CF. Chromatographic test methods for characterizing alkylsiloxane-bonded silica columns for reversed-phase liquid chromatography. J Chromatogr B Analyt Technol Biomed Life Sci 2018; 1092:207-219. [DOI: 10.1016/j.jchromb.2018.06.011] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2018] [Revised: 06/03/2018] [Accepted: 06/04/2018] [Indexed: 02/09/2023]
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16
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Salas D, Borrull F, Fontanals N, Marcé RM. Hydrophilic interaction liquid chromatography coupled to mass spectrometry-based detection to determine emerging organic contaminants in environmental samples. Trends Analyt Chem 2017. [DOI: 10.1016/j.trac.2017.07.017] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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17
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Selecting optimal columns for clarithromycin impurity analysis according to the quantitative relationship of hydrophobic subtraction model. J Pharm Biomed Anal 2017; 136:162-169. [DOI: 10.1016/j.jpba.2016.10.026] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2016] [Revised: 10/26/2016] [Accepted: 10/30/2016] [Indexed: 11/18/2022]
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18
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Ludvigsson JW, Karlsson A, Kjellberg V. Core-shell column Tanaka characterization and additional tests using active pharmaceutical ingredients. J Sep Sci 2016; 39:4520-4532. [DOI: 10.1002/jssc.201600769] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2016] [Revised: 09/27/2016] [Accepted: 09/29/2016] [Indexed: 11/10/2022]
Affiliation(s)
- Jufang Wu Ludvigsson
- Pharmaceutical Technology and Development; AstraZeneca R&D Gothenburg; Mölndal Sweden
| | - Anders Karlsson
- Pharmaceutical Technology and Development; AstraZeneca R&D Gothenburg; Mölndal Sweden
| | - Viktor Kjellberg
- Pharmaceutical Technology and Development; AstraZeneca R&D Gothenburg; Mölndal Sweden
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19
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Wei YZ, Zhuo RX, Jiang XL. Separation of polyethylene glycols and amino-terminated polyethylene glycols by high-performance liquid chromatography under near critical conditions. J Chromatogr A 2016; 1447:122-8. [DOI: 10.1016/j.chroma.2016.04.035] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2016] [Revised: 04/11/2016] [Accepted: 04/13/2016] [Indexed: 11/25/2022]
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20
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Huang G, Ou J, Wang H, Ji Y, Wan H, Zhang Z, Peng X, Zou H. Synthesis of a stationary phase based on silica modified with branched octadecyl groups by Michael addition and photoinduced thiol-yne click chemistry for the separation of basic compounds. J Sep Sci 2016; 39:1461-70. [DOI: 10.1002/jssc.201501403] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2015] [Revised: 02/11/2016] [Accepted: 02/11/2016] [Indexed: 11/10/2022]
Affiliation(s)
- Guang Huang
- CAS Key Laboratory of Separation Science for Analytical Chemistry, National Chromatographic R & A Center, Dalian Institute of Chemical Physics; Chinese Academy of Sciences (CAS); Dalian China
- University of Chinese Academy of Sciences; Beijing China
- State Key Laboratory of Fine Chemicals; Dalian University of Technology; Dalian China
| | - Junjie Ou
- CAS Key Laboratory of Separation Science for Analytical Chemistry, National Chromatographic R & A Center, Dalian Institute of Chemical Physics; Chinese Academy of Sciences (CAS); Dalian China
| | - Hongwei Wang
- CAS Key Laboratory of Separation Science for Analytical Chemistry, National Chromatographic R & A Center, Dalian Institute of Chemical Physics; Chinese Academy of Sciences (CAS); Dalian China
- University of Chinese Academy of Sciences; Beijing China
- State Key Laboratory of Fine Chemicals; Dalian University of Technology; Dalian China
| | - Yongsheng Ji
- CAS Key Laboratory of Separation Science for Analytical Chemistry, National Chromatographic R & A Center, Dalian Institute of Chemical Physics; Chinese Academy of Sciences (CAS); Dalian China
| | - Hao Wan
- CAS Key Laboratory of Separation Science for Analytical Chemistry, National Chromatographic R & A Center, Dalian Institute of Chemical Physics; Chinese Academy of Sciences (CAS); Dalian China
| | - Zhang Zhang
- CAS Key Laboratory of Separation Science for Analytical Chemistry, National Chromatographic R & A Center, Dalian Institute of Chemical Physics; Chinese Academy of Sciences (CAS); Dalian China
- University of Chinese Academy of Sciences; Beijing China
| | - Xiaojun Peng
- State Key Laboratory of Fine Chemicals; Dalian University of Technology; Dalian China
| | - Hanfa Zou
- CAS Key Laboratory of Separation Science for Analytical Chemistry, National Chromatographic R & A Center, Dalian Institute of Chemical Physics; Chinese Academy of Sciences (CAS); Dalian China
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21
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Cai T, Zhang H, Li Z, Rahman AFMM, Qiu H. A new nano-on-micro stationary phase based on nanodiamond bonded on silica for hydrophilic interaction chromatography. RSC Adv 2016. [DOI: 10.1039/c6ra04824b] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Nanodiamond particles were covalently bonded on silica microparticles and the resulting material was nicely decorated with a thin layer of oxidized nanodiamonds.
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Affiliation(s)
- Tianpei Cai
- Key Laboratory of Chemistry of Northwestern Plant Resources
- Key Laboratory for Natural Medicine of Gansu Province
- Lanzhou Institute of Chemical Physics
- Chinese Academy of Sciences
- Lanzhou 730000
| | - Haijuan Zhang
- Key Laboratory of Chemistry of Northwestern Plant Resources
- Key Laboratory for Natural Medicine of Gansu Province
- Lanzhou Institute of Chemical Physics
- Chinese Academy of Sciences
- Lanzhou 730000
| | - Zhan Li
- Key Laboratory of Chemistry of Northwestern Plant Resources
- Key Laboratory for Natural Medicine of Gansu Province
- Lanzhou Institute of Chemical Physics
- Chinese Academy of Sciences
- Lanzhou 730000
| | - A. F. M. Mustafizur Rahman
- Key Laboratory of Chemistry of Northwestern Plant Resources
- Key Laboratory for Natural Medicine of Gansu Province
- Lanzhou Institute of Chemical Physics
- Chinese Academy of Sciences
- Lanzhou 730000
| | - Hongdeng Qiu
- Key Laboratory of Chemistry of Northwestern Plant Resources
- Key Laboratory for Natural Medicine of Gansu Province
- Lanzhou Institute of Chemical Physics
- Chinese Academy of Sciences
- Lanzhou 730000
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22
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Sykora D, Vozka J, Tesarova E. Chromatographic methods enabling the characterization of stationary phases and retention prediction in high-performance liquid chromatography and supercritical fluid chromatography. J Sep Sci 2015; 39:115-31. [DOI: 10.1002/jssc.201501023] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2015] [Revised: 10/08/2015] [Accepted: 10/08/2015] [Indexed: 11/11/2022]
Affiliation(s)
- David Sykora
- Department of Analytical Chemistry; University of Chemistry and Technology; Prague Czech Republic
| | - Jiri Vozka
- Department of Analytical Chemistry; University of Chemistry and Technology; Prague Czech Republic
- Department of Physical and Macromolecular Chemistry, Faculty of Science; Charles University in Prague; Prague Czech Republic
| | - Eva Tesarova
- Department of Physical and Macromolecular Chemistry, Faculty of Science; Charles University in Prague; Prague Czech Republic
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23
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Abate-Pella D, Freund DM, Ma Y, Simón-Manso Y, Hollender J, Broeckling CD, Huhman DV, Krokhin OV, Stoll DR, Hegeman AD, Kind T, Fiehn O, Schymanski EL, Prenni JE, Sumner LW, Boswell PG. Retention projection enables accurate calculation of liquid chromatographic retention times across labs and methods. J Chromatogr A 2015; 1412:43-51. [PMID: 26292625 DOI: 10.1016/j.chroma.2015.07.108] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2015] [Revised: 07/24/2015] [Accepted: 07/31/2015] [Indexed: 10/23/2022]
Abstract
Identification of small molecules by liquid chromatography-mass spectrometry (LC-MS) can be greatly improved if the chromatographic retention information is used along with mass spectral information to narrow down the lists of candidates. Linear retention indexing remains the standard for sharing retention data across labs, but it is unreliable because it cannot properly account for differences in the experimental conditions used by various labs, even when the differences are relatively small and unintentional. On the other hand, an approach called "retention projection" properly accounts for many intentional differences in experimental conditions, and when combined with a "back-calculation" methodology described recently, it also accounts for unintentional differences. In this study, the accuracy of this methodology is compared with linear retention indexing across eight different labs. When each lab ran a test mixture under a range of multi-segment gradients and flow rates they selected independently, retention projections averaged 22-fold more accurate for uncharged compounds because they properly accounted for these intentional differences, which were more pronounced in steep gradients. When each lab ran the test mixture under nominally the same conditions, which is the ideal situation to reproduce linear retention indices, retention projections still averaged 2-fold more accurate because they properly accounted for many unintentional differences between the LC systems. To the best of our knowledge, this is the most successful study to date aiming to calculate (or even just to reproduce) LC gradient retention across labs, and it is the only study in which retention was reliably calculated under various multi-segment gradients and flow rates chosen independently by labs.
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Affiliation(s)
- Daniel Abate-Pella
- Department of Horticultural Science, University of Minnesota, 1970 Folwell Ave., St. Paul, MN 55108, USA.
| | - Dana M Freund
- Department of Horticultural Science, University of Minnesota, 1970 Folwell Ave., St. Paul, MN 55108, USA.
| | - Yan Ma
- UC Davis Genome Center, Metabolomics, University of California, Davis, Health Sciences Drive, Davis, CA 95616, USA.
| | - Yamil Simón-Manso
- Biomolecular Measurement Division, National Institute of Standards and Technology, Gaithersburg, MD 20899-8380, USA.
| | - Juliane Hollender
- Eawag: Swiss Federal Institute for Aquatic Science and Technology, Überlandstrasse 133, 8600 Dübendorf, Switzerland.
| | - Corey D Broeckling
- Proteomics and Metabolomics Facility, Colorado State University, Fort Collins, CO 80523, USA.
| | - David V Huhman
- The Samuel Roberts Noble Foundation, Ardmore, OK 73401, USA.
| | - Oleg V Krokhin
- Department of Internal Medicine, University of Manitoba, 799 JBRC, 715 McDermot Avenue, Winnipeg R3E 3P4, Canada.
| | - Dwight R Stoll
- Department of Chemistry, Gustavus Adolphus College, 800 West College Avenue, Saint Peter, MN 56082, USA.
| | - Adrian D Hegeman
- Department of Horticultural Science, University of Minnesota, 1970 Folwell Ave., St. Paul, MN 55108, USA.
| | - Tobias Kind
- UC Davis Genome Center, Metabolomics, University of California, Davis, Health Sciences Drive, Davis, CA 95616, USA.
| | - Oliver Fiehn
- UC Davis Genome Center, Metabolomics, University of California, Davis, Health Sciences Drive, Davis, CA 95616, USA; King Abdullaziz University, Department of Biochemistry, Jeddah, Saudi Arabia.
| | - Emma L Schymanski
- Eawag: Swiss Federal Institute for Aquatic Science and Technology, Überlandstrasse 133, 8600 Dübendorf, Switzerland.
| | - Jessica E Prenni
- Proteomics and Metabolomics Facility, Colorado State University, Fort Collins, CO 80523, USA.
| | - Lloyd W Sumner
- The Samuel Roberts Noble Foundation, Ardmore, OK 73401, USA.
| | - Paul G Boswell
- Department of Horticultural Science, University of Minnesota, 1970 Folwell Ave., St. Paul, MN 55108, USA.
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24
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Beyaza A, Fana W, Carr PW, Schellinger AP. Instrument parameters controlling retention precision in gradient elution reversed-phase liquid. J Chromatogr A 2015; 1371:90-105. [PMID: 25459648 DOI: 10.1016/j.chroma.2014.09.085] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2014] [Revised: 09/29/2014] [Accepted: 09/30/2014] [Indexed: 11/30/2022]
Abstract
The precision of retention time in RPLC is important for compound identification, for setting peak integration time windows and in fundamental studies of retention. In this work, we studied the effect of temperature (T), initial (ϕo) and final mobile phase (ϕf) composition, gradient time (tG), and flow rate (F) on the retention time precision under gradient elution conditions for various types of low MW solutes. We determined the retention factor in pure water ( [Formula: see text] ) and the solute-dependent solvent strength (S) parameters of Snyder's linear solvent strength theory (LSST) as a function of temperature for three different groups of solutes. The effect of small changes in the chromatographic variables (T, ϕo, ϕf, tG and F) by use of the LSST gradient retention equation were estimated. Peaks at different positions in the chromatogram have different sensitivities to changes in these instrument parameters. In general, absolute fluctuations in retention time are larger at longer gradient times. Drugs showed less sensitivity to changes in temperature compared to relatively less polar solutes, non-ionogenic solutes. Surprisingly we observed that fluctuations in temperature, mobile phase composition and flow rate had less effect on retention time under gradient conditions as compared to isocratic conditions. Overall temperature and the initial mobile phase composition are the most important variables affecting retention reproducibility in gradient elution chromatography.
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Affiliation(s)
- Ayse Beyaza
- Department of Chemistry, Smith and Kolthoff Halls, University of Minnesota, 207 Pleasant St. SE, Minneapolis, MN 55455, USA
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25
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Contributions to reversed-phase column selectivity. J Chromatogr A 2015; 1395:57-64. [DOI: 10.1016/j.chroma.2015.03.044] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2014] [Revised: 03/17/2015] [Accepted: 03/18/2015] [Indexed: 11/23/2022]
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26
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Zhang Y, Lucy CA. Effect of injection matrix concentration on peak shape and separation efficiency in ion chromatography. J Chromatogr A 2014; 1371:177-83. [DOI: 10.1016/j.chroma.2014.10.056] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2014] [Revised: 10/14/2014] [Accepted: 10/20/2014] [Indexed: 10/24/2022]
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27
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Practical considerations in comprehensive two-dimensional liquid chromatography systems (LCxLC) with reversed-phases in both dimensions. Anal Bioanal Chem 2014; 407:153-67. [DOI: 10.1007/s00216-014-8179-8] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2014] [Revised: 09/09/2014] [Accepted: 09/10/2014] [Indexed: 12/11/2022]
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28
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Allen RC, Barnes BB, Haidar Ahmad IA, Filgueira MR, Carr PW. Impact of reversed phase column pairs in comprehensive two-dimensional liquid chromatography. J Chromatogr A 2014; 1361:169-77. [PMID: 25169724 DOI: 10.1016/j.chroma.2014.08.012] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2014] [Revised: 08/02/2014] [Accepted: 08/05/2014] [Indexed: 10/24/2022]
Abstract
A major issue in optimizing the resolving power of two-dimensional chromatographic separations is the choice of the two phases so as to maximize the distribution of the analytes over the separation space. In this work, we studied the choice of appropriate reversed phases to use in on-line comprehensive two-dimensional liquid chromatography (LC×LC). A set of four chemically different conventional bonded reversed phases was used in the first dimension. The second dimension column was either a conventional bonded C18 phase or a carbon-clad phase (CCP). The LC×LC chromatograms and contour plots were all rather similar indicating that the selectivities of the two phases were also similar regardless of the reverse phase column used in the first dimension. Further, the spatial coverage seen with all four first dimension stationary phases when paired with a second dimension C18 phase were low and the retention times were strongly correlated. However, when the C18 column was replaced with the CCP column much improved separations were observed with higher spatial coverages, greater orthogonalities and significant increases in the number of observed peaks.
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Affiliation(s)
- Robert C Allen
- University of Minnesota, Department of Chemistry, Smith and Kolthoff Halls, 207 Pleasant Street SE, Minneapolis, MN 55455, USA
| | - Brian B Barnes
- University of Minnesota, Department of Chemistry, Smith and Kolthoff Halls, 207 Pleasant Street SE, Minneapolis, MN 55455, USA.
| | - Imad A Haidar Ahmad
- University of Minnesota, Department of Chemistry, Smith and Kolthoff Halls, 207 Pleasant Street SE, Minneapolis, MN 55455, USA
| | - Marcelo R Filgueira
- University of Minnesota, Department of Chemistry, Smith and Kolthoff Halls, 207 Pleasant Street SE, Minneapolis, MN 55455, USA
| | - Peter W Carr
- University of Minnesota, Department of Chemistry, Smith and Kolthoff Halls, 207 Pleasant Street SE, Minneapolis, MN 55455, USA
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29
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Comparative assessment of achiral stationary phases for high throughput analysis in supercritical fluid chromatography. J Chromatogr A 2014; 1332:73-81. [DOI: 10.1016/j.chroma.2014.01.060] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2013] [Revised: 01/18/2014] [Accepted: 01/20/2014] [Indexed: 11/21/2022]
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30
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Borges EM. How to select equivalent and complimentary reversed phase liquid chromatography columns from column characterization databases. Anal Chim Acta 2014; 807:143-52. [DOI: 10.1016/j.aca.2013.11.010] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2013] [Revised: 10/18/2013] [Accepted: 11/05/2013] [Indexed: 10/26/2022]
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31
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Poole CF, Ariyasena TC, Lenca N. Estimation of the environmental properties of compounds from chromatographic measurements and the solvation parameter model. J Chromatogr A 2013; 1317:85-104. [DOI: 10.1016/j.chroma.2013.05.045] [Citation(s) in RCA: 122] [Impact Index Per Article: 11.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2013] [Revised: 04/15/2013] [Accepted: 05/20/2013] [Indexed: 11/29/2022]
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32
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Lindsey RK, Rafferty JL, Eggimann BL, Siepmann JI, Schure MR. Molecular simulation studies of reversed-phase liquid chromatography. J Chromatogr A 2013; 1287:60-82. [PMID: 23489490 DOI: 10.1016/j.chroma.2013.02.040] [Citation(s) in RCA: 79] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2013] [Revised: 02/10/2013] [Accepted: 02/11/2013] [Indexed: 11/28/2022]
Abstract
Over the past 20 years, molecular simulation methods have been applied to the modeling of reversed-phase liquid chromatography (RPLC). The purpose of these simulations was to provide a molecular-level understanding of: (i) the structure and dynamics of the bonded phase and its interface with the mobile phase, (ii) the interactions of analytes with the bonded phase, and (iii) the retention mechanism for different analytes. However, the investigation of chromatographic systems poses significant challenges for simulations with respect to the accuracy of the molecular mechanics force fields and the efficiency of the sampling algorithms. This review discusses a number of aspects concerning molecular simulation studies of RPLC systems including the historical development of the subject, the background needed to understand the two prevalent techniques, molecular dynamics (MD) and Monte Carlo (MC) methods, and the wealth of insight provided by these simulations. Examples from the literature employing MD approaches and from the authors' laboratory using MC methods are discussed. The former can provide information on chain dynamics and transport properties, whereas the latter techniques are uniquely suited for the investigation of phase and sorption equilibria that underly RPLC retention, and both can be used to elucidate the bonded-chain conformations and solvent distributions.
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Affiliation(s)
- Rebecca K Lindsey
- Department of Chemistry and Chemical Theory Center, University of Minnesota, 207 Pleasant Street SE, Minneapolis, MN 55455-0431, USA
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33
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Ebinger K, Weller HN. Comparison of chromatographic techniques for diastereomer separation of a diverse set of drug-like compounds. J Chromatogr A 2013; 1272:150-4. [DOI: 10.1016/j.chroma.2012.11.065] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2012] [Revised: 11/21/2012] [Accepted: 11/25/2012] [Indexed: 11/30/2022]
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34
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Abstract
New analytical platforms have been developed in response to the need for attaining increased peak capacity for multicomponent complex analysis with higher sensitivity and characterization of the analytes, and high-throughput capabilities. This review outlines the fundamental principles of target and comprehensive 2D LC method development and encompasses applications of LC–LC and LC × LC coupled to MS in bioanalysis using a variety of online analytical procedures. It also provides a rationale for the usage of the most employed mass analyzers and ionization sources on these platforms.
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35
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Szulfer J, Plenis A, Bączek T. Application of a column classification method in a selectivity study involving caffeine and its related impurities. Talanta 2012; 99:492-501. [DOI: 10.1016/j.talanta.2012.06.015] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2012] [Revised: 06/04/2012] [Accepted: 06/06/2012] [Indexed: 10/28/2022]
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36
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Poole CF. Stationary phases for packed-column supercritical fluid chromatography. J Chromatogr A 2012; 1250:157-71. [DOI: 10.1016/j.chroma.2011.12.040] [Citation(s) in RCA: 56] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2011] [Revised: 12/11/2011] [Accepted: 12/12/2011] [Indexed: 10/14/2022]
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37
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VanMiddlesworth BJ, Dorsey JG. Quantifying injection solvent effects in reversed-phase liquid chromatography. J Chromatogr A 2012; 1236:77-89. [DOI: 10.1016/j.chroma.2012.02.075] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2011] [Revised: 02/27/2012] [Accepted: 02/28/2012] [Indexed: 11/29/2022]
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38
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Szulfer J, Plenis A, Bączek T. Evaluation of a column classification method using the separation of alfuzosin from its related substances. J Chromatogr A 2012; 1229:198-207. [DOI: 10.1016/j.chroma.2012.01.043] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2011] [Revised: 01/16/2012] [Accepted: 01/16/2012] [Indexed: 11/28/2022]
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39
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Tools to discover anionic and nonionic polyfluorinated alkyl surfactants by liquid chromatography electrospray ionisation mass spectrometry. J Chromatogr A 2011; 1218:7094-104. [DOI: 10.1016/j.chroma.2011.07.057] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2010] [Revised: 07/10/2011] [Accepted: 07/17/2011] [Indexed: 12/28/2022]
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40
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Contributions to reversed-phase column selectivity. II. Cation exchange. J Chromatogr A 2011; 1218:7110-29. [DOI: 10.1016/j.chroma.2011.07.085] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2011] [Revised: 06/18/2011] [Accepted: 07/26/2011] [Indexed: 11/19/2022]
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41
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Easy and accurate high-performance liquid chromatography retention prediction with different gradients, flow rates, and instruments by back-calculation of gradient and flow rate profiles. J Chromatogr A 2011; 1218:6742-9. [DOI: 10.1016/j.chroma.2011.07.070] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2011] [Revised: 07/09/2011] [Accepted: 07/21/2011] [Indexed: 11/19/2022]
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42
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Boswell PG, Schellenberg JR, Carr PW, Cohen JD, Hegeman AD. A study on retention “projection” as a supplementary means for compound identification by liquid chromatography–mass spectrometry capable of predicting retention with different gradients, flow rates, and instruments. J Chromatogr A 2011; 1218:6732-41. [DOI: 10.1016/j.chroma.2011.07.105] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2011] [Revised: 07/09/2011] [Accepted: 07/21/2011] [Indexed: 11/16/2022]
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43
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Separation of 9,10-anthraquinone derivatives: Evaluation of functionalised stationary phases in reversed phase mode. J Chromatogr A 2011; 1218:3636-47. [DOI: 10.1016/j.chroma.2011.04.012] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2011] [Revised: 04/01/2011] [Accepted: 04/04/2011] [Indexed: 11/21/2022]
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44
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Contributions to reversed-phase column selectivity. I. Steric interaction. J Chromatogr A 2011; 1218:1724-42. [DOI: 10.1016/j.chroma.2011.01.047] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2010] [Revised: 01/16/2011] [Accepted: 01/17/2011] [Indexed: 11/22/2022]
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45
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Zhang Y, Carr PW. Novel ultra stable silica-based stationary phases for reversed phase liquid chromatography--study of a hydrophobically assisted weak acid cation exchange phase. J Chromatogr A 2011; 1218:763-77. [PMID: 21227426 PMCID: PMC3027354 DOI: 10.1016/j.chroma.2010.11.009] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2010] [Revised: 10/31/2010] [Accepted: 11/08/2010] [Indexed: 10/18/2022]
Abstract
A mixed-mode reversed-phase/weak cation exchange (RP/WCX) phase has been developed by introducing a small amount of carboxylate functionality into a hydrophobic hyper-crosslinked (HC) platform. This silica-based HC platform was designed to form an extensive polystyrene network completely confined to the particle's surface. The fully connected polymer network prevents the loss of bonded phase, which leads to superior hydrolytic stability of the new phase when compared to conventional silica-based phases. Compared to previously introduced HC phases the added carboxylic groups impart a new weak cation exchange selectivity to the base hydrophobic HC platform. The phase thus prepared shows a mixed-mode retention mechanism, allowing for both neutral organic compounds and bases of a wide polarity range to be simultaneously separated on the same phase under the same conditions. In addition, the new phase offers the flexibility that gradients in organic modifier, pH or ionic competitors can be used to affect the separation of a wide range of solutes. Moreover, the inherent weak acid cation exchange groups allow formic and acetic acid buffers to be used as eluents thereby avoiding the mass spectrometric ionization suppression problems concomitant to the use of non-volatile additives such as strong amine modifiers (e.g. triethylamine) or salts (e.g. NaCl) to elute basic solutes from the strong cation exchange phase which was previously developed in this lab. The use of the new phase for achieving strong retention of rather hydrophilic neurotransmitters and drugs of abuse without the need for ion pairing agents is demonstrated.
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Affiliation(s)
- Yu Zhang
- University of Minnesota, 207 Pleasant St. SE, Minneapolis, MN 55455, USA
| | - Peter W. Carr
- University of Minnesota, 207 Pleasant St. SE, Minneapolis, MN 55455, USA
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46
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Characterization of ion chromatography columns based on hydrophobicity and hydroxide eluent strength. J Chromatogr A 2010; 1217:8154-60. [DOI: 10.1016/j.chroma.2010.10.065] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2010] [Revised: 10/13/2010] [Accepted: 10/15/2010] [Indexed: 11/23/2022]
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47
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Characterization of adsorption processes in analytical liquid–solid chromatography. J Chromatogr A 2010; 1217:792-812. [DOI: 10.1016/j.chroma.2009.12.044] [Citation(s) in RCA: 76] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2009] [Revised: 12/15/2009] [Accepted: 12/17/2009] [Indexed: 11/22/2022]
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48
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Atapattu SN, Poole CF. Factors Affecting the Interpretation of Selectivity on Synergi Reversed-Phase Columns. Chromatographia 2009. [DOI: 10.1365/s10337-009-1431-2] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
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49
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McCalley DV. The challenges of the analysis of basic compounds by high performance liquid chromatography: some possible approaches for improved separations. J Chromatogr A 2009; 1217:858-80. [PMID: 20031138 DOI: 10.1016/j.chroma.2009.11.068] [Citation(s) in RCA: 182] [Impact Index Per Article: 12.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2009] [Revised: 10/13/2009] [Accepted: 11/23/2009] [Indexed: 11/18/2022]
Abstract
This review considers some of the difficulties encountered with the analysis of ionised bases using reversed-phase chromatography, such as detrimental interaction with column silanol groups, and overloading which both lead to poor peak shapes. Methods of overcoming these problems in reversed-phase (RP) separations, by judicious selection of the column and mobile phase conditions, are discussed. Hydrophilic interaction chromatography is considered as an alternative method for the separation of some basic compounds.
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Affiliation(s)
- David V McCalley
- Centre for Research in Biomedicine, University of the West of England, Frenchay, Bristol BS16 1QY, UK.
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50
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Poole CF, Atapattu SN, Poole SK, Bell AK. Determination of solute descriptors by chromatographic methods. Anal Chim Acta 2009; 652:32-53. [DOI: 10.1016/j.aca.2009.04.038] [Citation(s) in RCA: 189] [Impact Index Per Article: 12.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2009] [Revised: 04/25/2009] [Accepted: 04/28/2009] [Indexed: 11/24/2022]
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