1
|
Dhellemmes L, Leclercq L, Frick H, Höchsmann A, Schaschke N, Neusüß C, Cottet H. Investigating cationic and zwitterionic successive multiple ionic-polymer layer coatings for protein separation by capillary electrophoresis. J Chromatogr A 2024; 1720:464802. [PMID: 38507871 DOI: 10.1016/j.chroma.2024.464802] [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: 01/17/2024] [Revised: 03/04/2024] [Accepted: 03/05/2024] [Indexed: 03/22/2024]
Abstract
Successive multiple ionic-polymer layers (SMILs) have long since proved their worth in capillary electrophoresis as they ensure stable electroosmotic flow (EOF) and relatively high separation efficiency. Recently, we demonstrated that plotting the plate height (H) against the solute migration velocity (u) enabled a reliable quantitative evaluation of the coating performances in terms of separation efficiency. In this work, various physicochemical and chemical parameters of the SMIL coating were studied and optimized in order to decrease the slope of the ascending part of the H vs u curve, which is known to be controlled by the homogeneity in charge of the coating surface and by the possible residual solute adsorption onto the coating surface. SMILs based on poly(diallyldimethylammonium chloride) (PDADMAC) and poly(sodium styrene sulfonate) (PSS) were formed and the effect of each polyelectrolyte molar mass and of the number of polyelectrolyte layers (up to 21 layers) was studied. The use of polyethylene imine as an anchoring first layer was considered. More polyelectrolyte couples based on PDADMAC, polybrene, PSS, poly(vinyl sulfate), and poly(acrylic acid) were tested. Finally, zwitterionic polymers based on the poly(α-l-lysine) scaffold were synthesized and used as the last layer of SMILs, illustrating their ability to finetune the EOF, while maintaining good separation efficiency.
Collapse
Affiliation(s)
- Laura Dhellemmes
- IBMM, University of Montpellier, CNRS, ENSCM, Montpellier, France
| | - Laurent Leclercq
- IBMM, University of Montpellier, CNRS, ENSCM, Montpellier, France
| | - Henry Frick
- Faculty of Chemistry, Aalen University, Aalen, Germany
| | | | | | | | - Hervé Cottet
- IBMM, University of Montpellier, CNRS, ENSCM, Montpellier, France.
| |
Collapse
|
2
|
Roca S, Leclercq L, Cottet H. Size-based characterization of dendrigraft poly(L-lysine) by free solution capillary electrophoresis using polyelectrolyte multilayer coatings. J Chromatogr A 2024; 1718:464719. [PMID: 38340458 DOI: 10.1016/j.chroma.2024.464719] [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: 11/16/2023] [Revised: 01/28/2024] [Accepted: 02/03/2024] [Indexed: 02/12/2024]
Abstract
Dendrigraft poly(L-lysine) (DGL) constitutes a promising dendritic-like drug vehicle with high biocompatibility and straightforward access via ring-opening polymerization of N-carboxyanhydride in water. The characterization of the different generations of DGL is however challenging due to their heterogeneity in molar mass and branching ratio. In this work, free solution capillary electrophoresis was used to perform selective separation of the three first generations of DGL, and optimized conditions were developed to maximize inter-generation resolution. To reduce solute adsorption on the capillary wall, successive multiple ionic polymer layer coatings terminated with a polycation were deposited onto the inner wall surface. PEGylated polycation was also used as the last layer for the control of the electroosmotic flow (EOF), depending on the PEGylation degree and the methyl-polyethylene glycol (mPEG) chain length. 1 kDa mPEG chains and low grafting densities were found to be the best experimental conditions for a fine tuning of the EOF leading to high peak resolution. Molar mass polydispersity and polydispersity in effective electrophoretic mobility were successfully determined for the three first generations of DGL.
Collapse
Affiliation(s)
- Sébastien Roca
- IBMM, University of Montpellier, CNRS, ENSCM, Montpellier, France
| | - Laurent Leclercq
- IBMM, University of Montpellier, CNRS, ENSCM, Montpellier, France.
| | - Hervé Cottet
- IBMM, University of Montpellier, CNRS, ENSCM, Montpellier, France.
| |
Collapse
|
3
|
Modifying last layer in polyelectrolyte multilayer coatings for capillary electrophoresis of proteins. J Chromatogr A 2023; 1692:463837. [PMID: 36804799 DOI: 10.1016/j.chroma.2023.463837] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2022] [Revised: 01/23/2023] [Accepted: 01/27/2023] [Indexed: 02/04/2023]
Abstract
Protein adsorption on the inner wall of the fused silica capillary wall is an important concern for capillary electrophoresis (CE) analysis since it is mainly responsible for separation efficiency reduction. Successive Multiple Ionic-polymer Layers (SMIL) are used as capillary coatings to limit protein adsorption, but even low residual adsorption strongly impacts the separation efficiency, especially at high separation voltages. In this work, the influence of the chemical nature and the PEGylation of the polyelectrolyte deposited in the last layer of the SMIL coating was investigated on the separation performances of a mixture of four model intact proteins (myoglobin (Myo), trypsin inhibitor (TI), ribonuclease a (RNAse A) and lysozyme (Lyz)). Poly(allylamine hydrochloride) (PAH), polyethyleneimine (PEI), ε-poly(L-lysine) (εPLL) and α-poly(L-lysine) (αPLL) were compared before and after chemical modification with polyethyleneglycol (PEG) of different chain lengths. The experimental results obtained by performing electrophoretic separations at different separation voltages allowed determining the residual retention factor of the proteins onto the capillary wall via the determination of the plate height at different solute velocities and demonstrated a strong impact of the polycationic last layer on the electroosmotic mobility, the separation efficiency and the overall resolution. Properties of SMIL coatings were also characterized by quartz microbalance and atomic force microscopy, demonstrating a glassy structure of the films.
Collapse
|
4
|
Dhellemmes L, Leclercq L, Höchsmann A, Neusüß C, Biron JP, Roca S, Cottet H. Critical parameters for highly efficient and reproducible polyelectrolyte multilayer coatings for protein separation by capillary electrophoresis. J Chromatogr A 2023; 1695:463912. [PMID: 36972664 DOI: 10.1016/j.chroma.2023.463912] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2023] [Revised: 03/01/2023] [Accepted: 03/02/2023] [Indexed: 03/08/2023]
Abstract
Since the introduction of polyelectrolyte multilayers to protein separation in capillary electrophoresis (CE), some progress has been made to improve separation efficiency by varying different parameters, such as buffer ionic strength and pH, polyelectrolyte nature and number of deposited layers. However, CE is often overlooked as it lacks robustness compared to other separation techniques. In this work, critical parameters for the construction of efficient and reproducible Successive multiple ionic-polymer layers (SMIL) coatings were investigated, focusing on experimental conditions, such as vial preparation and sample conservation which were shown to have a significant impact on separation performances. In addition to repeatability, intra- and inter-capillary precision were assessed, demonstrating the improved capability of poly(diallyldimethylammonium chloride) / poly(sodium styrene sulfonate) (PDADMAC / PSS) coated capillaries to separate model proteins in a 2 M acetic acid background electrolyte when all the correct precautions are put in place (with run to run%RSD(tm) < 1.8%, day to day%RSD(tm) < 3.2% and cap to cap%RSD(tm) < 4.6%). The approach recently introduced to calculate retention factors was used to quantify residual protein adsorption onto the capillary wall and to assess capillary coating performances. 5-layer PDADAMAC / PSS coatings led to average retention factors for the five model proteins of ∼4×10-2. These values suggest a relatively low residual protein adsorption leading to reasonably flat plate height vs linear velocity curves, obtained by performing electrophoretic separations at different electrical voltages (-10 to -25 kV).
Collapse
|
5
|
Šolínová V, Tůma P, Butnariu M, Kašička V, Koval D. Covalent anionic copolymer coatings with tunable electroosmotic flow for optimization of capillary electrophoretic separations. Electrophoresis 2022; 43:1953-1962. [DOI: 10.1002/elps.202200130] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2022] [Revised: 07/28/2022] [Accepted: 08/08/2022] [Indexed: 11/06/2022]
Affiliation(s)
- Veronika Šolínová
- Institute of Organic Chemistry and Biochemistry of the Czech Academy of Sciences Prague 6 Czech Republic
| | - Petr Tůma
- Department of Hygiene, Third Faculty of Medicine Charles University Prague 10 Czech Republic
| | - Maria Butnariu
- Institute of Organic Chemistry and Biochemistry of the Czech Academy of Sciences Prague 6 Czech Republic
- Department of Analytical Chemistry, Faculty of Science Charles University Prague 2 Czech Republic
| | - Václav Kašička
- Institute of Organic Chemistry and Biochemistry of the Czech Academy of Sciences Prague 6 Czech Republic
| | - Dušan Koval
- Institute of Organic Chemistry and Biochemistry of the Czech Academy of Sciences Prague 6 Czech Republic
| |
Collapse
|
6
|
Sensitive monitoring of 3-hydroxybutyrate as an indicator of human fasting by capillary electrophoresis in a PAMAMPS coated capillary. Talanta 2022; 247:123582. [DOI: 10.1016/j.talanta.2022.123582] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2022] [Revised: 05/19/2022] [Accepted: 05/20/2022] [Indexed: 11/20/2022]
|
7
|
Vaghef-Koodehi A, Dillis C, Lapizco-Encinas BH. High-Resolution Charge-Based Electrokinetic Separation of Almost Identical Microparticles. Anal Chem 2022; 94:6451-6456. [PMID: 35441512 DOI: 10.1021/acs.analchem.2c00355] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Well-established techniques, e.g., chromatography and capillary electrophoresis, are available for separating nanosized particles, such as proteins. However, similar techniques for separating micron-sized particles are still needed. Insulator-based electrokinetic (iEK) systems can achieve efficient microparticle separations by combining linear and nonlinear EK phenomena. Of particular interest are charge-based separations, which could be employed for separating similar microorganisms, such as bacterial cells of the same size, same genus, or same strain. Several groups have reported charge-based separations of microparticles where a zeta potential difference of at least 40 mV between the microparticles was required. The present work pushes the limit of the discriminatory capabilities of iEK systems by reporting the charged-based separation of two microparticles of the same size (5.1 μm), same shape, same substrate material, and with a small difference in particle zeta potentials of only 3.6 mV, which is less than 10% of the difference in previous studies. By building an accurate COMSOL Multiphysics model, which correctly accounts for dielectrophoresis and electrophoresis of the second kind, it was possible to identify the conditions to achieve this challenging separation. Furthermore, the COMSOL model allowed predicting particle retention times (tR,p) which were compared with experimental values (tR,e). The separations results had excellent reproducibility in terms of tR,e with variations of only 9% and 11% between repetitions. These findings demonstrate that, by following a robust protocol that involves modeling and experimental work, it is possible to discriminate between highly similar particles, with much smaller differences in electrical charge than previously reported.
Collapse
Affiliation(s)
- Alaleh Vaghef-Koodehi
- Microscale Bioseparations Laboratory and Biomedical Engineering Department, Rochester Institute of Technology, 160 Lomb Memorial Drive, Rochester, New York 14623, United States
| | - Curran Dillis
- Microscale Bioseparations Laboratory and Biomedical Engineering Department, Rochester Institute of Technology, 160 Lomb Memorial Drive, Rochester, New York 14623, United States
| | - Blanca H Lapizco-Encinas
- Microscale Bioseparations Laboratory and Biomedical Engineering Department, Rochester Institute of Technology, 160 Lomb Memorial Drive, Rochester, New York 14623, United States
| |
Collapse
|
8
|
Roca S, Dhellemmes L, Leclercq L, Cottet H. Polyelectrolyte Multilayers in Capillary Electrophoresis. Chempluschem 2022; 87:e202200028. [PMID: 35388990 DOI: 10.1002/cplu.202200028] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2022] [Revised: 03/19/2022] [Indexed: 02/21/2024]
Abstract
Capillary electrophoresis (CE) has been proven to be a performant analytical method to analyze both small and macro molecules. Indeed, it is capable of separating compounds of the same nature according to differences in their charge to size ratios, particularly proteins, monoclonal antibodies and peptides. However, one of the major obstacles to reach high separation efficiency remains the adsorption of solutes on the capillary wall. Among the different coating approaches used to control and minimize solute adsorption, polyelectrolyte multilayers can be applied to CE as a versatile approach. These coatings are made up of alternating layers of polycations and polyanions, and may be used in acidic, neutral or basic conditions depending on the solutes to be analyzed. This Review provides an overview of Successive Multiple Ionic-polymer Layer (SMIL) coatings used in CE, looking at how different parameters induce variations on the electro-osmotic flow (EOF), separation efficiency and coating stability, as well as their promising applications in the biopharmaceutical field.
Collapse
Affiliation(s)
- Sébastien Roca
- IBMM, University of Montpellier, CNRS, ENSCM, Montpellier, France
| | - Laura Dhellemmes
- IBMM, University of Montpellier, CNRS, ENSCM, Montpellier, France
| | - Laurent Leclercq
- IBMM, University of Montpellier, CNRS, ENSCM, Montpellier, France
| | - Hervé Cottet
- IBMM, University of Montpellier, CNRS, ENSCM, Montpellier, France
| |
Collapse
|
9
|
Yu RB, Quirino JP. Chiral separation using cyclodextrins as mobile phase additives in open-tubular liquid chromatography with a pseudophase coating. J Sep Sci 2022; 45:1195-1201. [PMID: 35014193 PMCID: PMC9304321 DOI: 10.1002/jssc.202100835] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2021] [Revised: 01/07/2022] [Accepted: 01/08/2022] [Indexed: 11/22/2022]
Abstract
The chiral separation of various analytes (dichlorprop, mecoprop, ibuprofen, and ketoprofen) was demonstrated with different cyclodextrins as mobile phase additives in open-tubular liquid chromatography using a stationary pseudophase semipermanent coating. The stable coating was prepared by a successive multiple ionic layer approach using poly(diallyldimethylammonium chloride), polystyrene sulfonate, and didodecyldimethyl ammonium bromide. Increasing concentrations (0-0.2 mM) of various native and derivatized cyclodextrins in 25 mM sodium tetraborate (pH 9.2) were investigated. Chiral separation was achieved for the four test analytes using 0.05-0.1 mM β-cyclodextrin (resolution between 1.11 and 1.34), γ-cyclodextrin (resolution between 0.78 and 1.27), carboxymethyl-β-cyclodextrin (resolution between 1.64 and 2.59), and 2-hydroxypropyl-β-cyclodextrin (resolution between 0.71 and 1.76) with the highest resolutions obtained with 0.1 mM carboxymethyl-β-cyclodextrin. %RSD values were <10%. This is the first demonstration of chiral open-tubular liquid chromatography using achiral chromatographic coatings and cyclodextrins as mobile phase additives.
Collapse
Affiliation(s)
- Raymond B. Yu
- Australian Centre for Research on Separation ScienceSchool of Natural Sciences‐ChemistryUniversity of TasmaniaHobartTasmaniaAustralia
| | - Joselito P. Quirino
- Australian Centre for Research on Separation ScienceSchool of Natural Sciences‐ChemistryUniversity of TasmaniaHobartTasmaniaAustralia
| |
Collapse
|
10
|
Leclercq X, Leclercq L, Guillard A, Rodriguez L, Braun O, Favero C, Cottet H. Determination of ultrahigh molar mass of polyelectrolytes by Taylor dispersion analysis. J Chromatogr A 2022; 1670:462949. [DOI: 10.1016/j.chroma.2022.462949] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2022] [Revised: 03/07/2022] [Accepted: 03/07/2022] [Indexed: 10/18/2022]
|
11
|
Stolz A, Neusüß C. Characterisation of a new online nanoLC-CZE-MS platform and application for the glycosylation profiling of alpha-1-acid glycoprotein. Anal Bioanal Chem 2022; 414:1745-1757. [PMID: 34881393 PMCID: PMC8791864 DOI: 10.1007/s00216-021-03814-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2021] [Revised: 11/19/2021] [Accepted: 11/30/2021] [Indexed: 11/22/2022]
Abstract
The ever-increasing complexity of biological samples to be analysed by mass spectrometry has led to the necessity of sophisticated separation techniques, including multidimensional separation. Despite a high degree of orthogonality, the coupling of liquid chromatography (LC) and capillary zone electrophoresis (CZE) has not gained notable attention in research. Here, we present a heart-cut nanoLC-CZE-ESI-MS platform to analyse intact proteins. NanoLC and CZE-MS are coupled using a four-port valve with an internal nanoliter loop. NanoLC and CZE-MS conditions were optimised independently to find ideal conditions for the combined setup. The valve setup enables an ideal transfer efficiency between the dimensions while maintaining good separation conditions in both dimensions. Due to the higher loadability, the nanoLC-CZE-MS setup exhibits a 280-fold increased concentration sensitivity compared to CZE-MS. The platform was used to characterise intact human alpha-1-acid glycoprotein (AGP), an extremely heterogeneous N-glycosylated protein. With the nanoLC-CZE-MS approach, 368 glycoforms can be assigned at a concentration of 50 μg/mL as opposed to the assignment of only 186 glycoforms from 1 mg/mL by CZE-MS. Additionally, we demonstrate that glycosylation profiling is accessible for dried blood spot analysis (25 μg/mL AGP spiked), indicating the general applicability of our setup to biological matrices. The combination of high sensitivity and orthogonal selectivity in both dimensions makes the here-presented nanoLC-CZE-MS approach capable of detailed characterisation of intact proteins and their proteoforms from complex biological samples and in physiologically relevant concentrations.
Collapse
Affiliation(s)
- Alexander Stolz
- Faculty of Chemistry, Aalen University, Beethovenstr. 1, 73430, Aalen, Germany
- Department of Pharmaceutical and Medicinal Chemistry, Friedrich Schiller University, 07743, Jena, Germany
| | - Christian Neusüß
- Faculty of Chemistry, Aalen University, Beethovenstr. 1, 73430, Aalen, Germany.
| |
Collapse
|
12
|
Štěpánová S, Kašička V. Applications of capillary electromigration methods for separation and analysis of proteins (2017–mid 2021) – A review. Anal Chim Acta 2022; 1209:339447. [DOI: 10.1016/j.aca.2022.339447] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2021] [Revised: 01/04/2022] [Accepted: 01/04/2022] [Indexed: 12/11/2022]
|
13
|
Salzer L, Stolz A, Dhellemmes L, Höchsmann A, Leclercq L, Cottet H, Neusüß C. Successive Multiple Ionic-Polymer Layer Coatings for Intact Protein Analysis by Capillary Zone Electrophoresis-Mass Spectrometry: Application to Hemoglobin Analysis. Methods Mol Biol 2022; 2531:69-76. [PMID: 35941479 DOI: 10.1007/978-1-0716-2493-7_5] [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] [Indexed: 06/15/2023]
Abstract
Adsorption of analytes, e.g., proteins, often interfere with separation in CE, due to the relatively large surface of the narrow capillary. Coatings often are applied to prevent adsorption and to determine the electroosmotic flow (EOF), which is of major importance for the separation in CE. Successive multiple ionic-polymer layer (SMIL) coatings are frequently used for protein analysis in capillary electrophoresis resulting in high separation efficiency and repeatability. Here, the coating procedure of a five-layer SMIL coating is described using quaternized diethylaminoethyl dextran (DEAEDq) as polycation and poly(methacrylic acid) (PMA) as polyanion. Depending on the analyte, different polyions may be used to increase separation efficiency. However, the coating procedure remains the same.To demonstrate the applicability of SMIL coatings in CE-MS, human hemoglobin was measured in a BGE containing 2 M acetic acid. DEAEDq-PMA coating was found to be the most suitable for hemoglobin analysis due to relatively low reversed electroosmotic mobility leading to increased electrophoretic resolution of closely related proteoforms. Thereby, not only alpha and beta subunit of the hemoglobin could be separated, but also positional isoforms of glycated and carbamylated species were separated within 24 min.
Collapse
Affiliation(s)
- Liesa Salzer
- Faculty of Chemistry, Aalen University, Aalen, Germany
- Analytical BioGeoChemistry (BGC), Helmholtz Zentrum München, Neuherberg, Germany
| | | | - Laura Dhellemmes
- Institut des Biomolécules Max Mousseron, UMR CNRS, Université de Montpellier, Montpellier, France
| | | | - Laurent Leclercq
- Institut des Biomolécules Max Mousseron, UMR CNRS, Université de Montpellier, Montpellier, France
| | - Hervé Cottet
- Institut des Biomolécules Max Mousseron, UMR CNRS, Université de Montpellier, Montpellier, France
| | | |
Collapse
|
14
|
Kašička V. Recent developments in capillary and microchip electroseparations of peptides (2019-mid 2021). Electrophoresis 2021; 43:82-108. [PMID: 34632606 DOI: 10.1002/elps.202100243] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2021] [Revised: 09/29/2021] [Accepted: 09/30/2021] [Indexed: 12/19/2022]
Abstract
The review provides a comprehensive overview of developments and applications of high performance capillary and microchip electroseparation methods (zone electrophoresis, isotachophoresis, isoelectric focusing, affinity electrophoresis, electrokinetic chromatography, and electrochromatography) for analysis, microscale isolation, and physicochemical characterization of peptides from 2019 up to approximately the middle of 2021. Advances in the investigation of electromigration properties of peptides and in the methodology of their analysis, such as sample preparation, sorption suppression, EOF control, and detection, are presented. New developments in the individual CE and CEC methods are demonstrated and several types of their applications are shown. They include qualitative and quantitative analysis, determination in complex biomatrices, monitoring of chemical and enzymatic reactions and physicochemical changes, amino acid, sequence, and chiral analyses, and peptide mapping of proteins. In addition, micropreparative separations and determination of significant physicochemical parameters of peptides by CE and CEC methods are described.
Collapse
Affiliation(s)
- Václav Kašička
- Institute of Organic Chemistry and Biochemistry, The Czech Academy of Sciences, Prague 6, Czechia
| |
Collapse
|
15
|
Covalent cationic copolymer coatings allowing tunable electroosmotic flow for optimization of capillary electrophoretic separations. Anal Chim Acta 2021; 1178:338789. [PMID: 34482877 DOI: 10.1016/j.aca.2021.338789] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2021] [Revised: 06/11/2021] [Accepted: 06/20/2021] [Indexed: 11/22/2022]
Abstract
Electroosmotic flow (EOF) plays a pivotal role in optimization of capillary electrophoresis (CE) separations of (bio)molecules and (bio)particles. EOF velocity is directly related to analysis time, peak resolution and separation efficiency. Here, we report a concept of charged polymer coatings of the inner fused silica capillary wall, which allows anodic EOF with mobility ranging from 0 to ∼(30-40) × 10-9 m2V-1s-1. The capillary wall is modified by covalently bound cationic copolymer poly(acrylamide-co-(3-acrylamidopropyl)trimethylammonium chloride) (PAMAPTAC) containing variable ratio of the charged monomer in the 0-60 mol. % interval. The EOF mobility showed minor variability with composition of background electrolyte (BGE) and pH in the 2-10 interval. The coatings were evaluated by CE-UV and nanospray CE-MS in the counter-EOF arrangement for a series of basic drug molecules in acetic acid based acidic BGE. Tunable EOF velocity was demonstrated as a useful tool for optimization of peak resolution, separation efficiency and migration time of analytes. Electrostatic repulsion of positively charged capillary surface was shown as beneficial for suppression of analyte adsorption, notably for hydrophobic cationic analytes.
Collapse
|
16
|
Hamidli N, Andrasi M, Nagy C, Gaspar A. Analysis of intact proteins with capillary zone electrophoresis coupled to mass spectromery using uncoated and coated capillaries. J Chromatogr A 2021; 1654:462448. [PMID: 34392123 DOI: 10.1016/j.chroma.2021.462448] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2021] [Revised: 07/28/2021] [Accepted: 07/28/2021] [Indexed: 10/20/2022]
Abstract
Although, in general, the application of coated capillaries is recommended for the separation of intact proteins, bare silica capillary is still the most often used capillary due to its simplicity and cheapness. In this work, the performance of bare fused silica capillary for intact protein analysis was compared to that of different (dynamically coated polybrene (PB) and permanently coated linear polyacrylamide (LPA)) coated capillaries using capillary zone electrophoresis - mass spectrometry (CZE-MS). In cases where low pH (pH=1.8) was used in bare silica capillaries, good precision (0.56-0.78 RSD% and 1.7-6.5 RSD% for migration times and peak areas, respectively), minimal adsorption and separation efficiency (N= 27 000/m - 322 000/m) similar to or even better than those obtained with the coated capillaries (created by an intricate multi-step process) was achieved. The PB and the LPA capillaries demonstrated their slightly better resolving power in terms of separating the different forms/variants of the same protein (e.g., hemoglobin subunits). Among the studied capillaries the one with LPA coating showed the most stable separations in the long term (n=25: 0.18-0.49 RSD% and 3.1-4.9 RSD% for migration times and peak areas, respectively). For the separation of a few proteins or even a larger number of proteins in biological samples (e.g., snake venom) the application of the simple and cheap bare fused silica capillary can be considered as an efficient choice.
Collapse
Affiliation(s)
- N Hamidli
- Department of Inorganic and Analytical Chemistry, University of Debrecen, Egyetem ter 1, H-4032, Debrecen, Hungary
| | - M Andrasi
- Department of Inorganic and Analytical Chemistry, University of Debrecen, Egyetem ter 1, H-4032, Debrecen, Hungary
| | - C Nagy
- Department of Inorganic and Analytical Chemistry, University of Debrecen, Egyetem ter 1, H-4032, Debrecen, Hungary
| | - A Gaspar
- Department of Inorganic and Analytical Chemistry, University of Debrecen, Egyetem ter 1, H-4032, Debrecen, Hungary.
| |
Collapse
|
17
|
Farmerie L, Rustandi RR, Loughney JW, Dawod M. Recent advances in isoelectric focusing of proteins and peptides. J Chromatogr A 2021; 1651:462274. [PMID: 34090060 DOI: 10.1016/j.chroma.2021.462274] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2021] [Revised: 05/13/2021] [Accepted: 05/16/2021] [Indexed: 12/18/2022]
Abstract
This review article describes the significant recent advances in Isoelectric Focusing from the period 2015-2020. The review highlights the principles and common challenges faced in Isoelectric Focusing as well as its applications. This review also details the recent advances in various modes of Isoelectric Focusing in various platforms and future directions for the technique.
Collapse
Affiliation(s)
- Lily Farmerie
- Analytical Research & Development, Merck & Co., Inc., Kenilworth, NJ, USA; Pennsylvania State University, College of Engineering, University Park, PA, USA
| | - Richard R Rustandi
- Analytical Research & Development, Merck & Co., Inc., Kenilworth, NJ, USA
| | - John W Loughney
- Analytical Research & Development, Merck & Co., Inc., Kenilworth, NJ, USA
| | - Mohamed Dawod
- Analytical Research & Development, Merck & Co., Inc., Kenilworth, NJ, USA.
| |
Collapse
|
18
|
Xing J, Wang F, Cong H, Wang S, Shen Y, Yu B. Analysis of proteins and chiral drugs based on vancomycin covalent capillary electrophoretic coating. Analyst 2020; 146:1320-1325. [PMID: 33367313 DOI: 10.1039/d0an02018d] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
Vancomycin is an amphoteric glycopeptide molecule, and its group diversity and chiral active sites provide a potential basis for its application in chromatographic analysis. In this article, using photosensitive diazo resin (DR) as the coupling agent, vancomycin is modified on the inner wall of the capillary to construct a capillary coating separation system. The highlight of the coated capillary is that it has both anti-protein adsorption and chiral separation properties. Compared with the bare capillary or non-covalently bonded DR/vancomycin-coated capillary, it can not only achieve the separation of four mixed proteins of lysozyme (Lys), bovine serum albumin (BSA), myoglobin (Mb), and ribonuclease A (RNase A), but also shows excellent performance in chiral drugs. The coated capillary effectively solves the problems of low efficiency of the separation column and high sample loss and provides ideas for the development of coated capillaries in the future.
Collapse
Affiliation(s)
- Jie Xing
- Institute of Biomedical Materials and Engineering, College of Chemistry and Chemical Engineering, College of Materials Science and Engineering, Affiliated Hospital of Qingdao University, Qingdao University, Qingdao 266071, China.
| | | | | | | | | | | |
Collapse
|
19
|
|
20
|
Wang F, Cong H, Xing J, Wang S, Shen Y, Yu B. Novel antifouling polymer with self-cleaning efficiency as surface coating for protein analysis by electrophoresis. Talanta 2020; 221:121493. [PMID: 33076098 DOI: 10.1016/j.talanta.2020.121493] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2020] [Revised: 07/27/2020] [Accepted: 07/30/2020] [Indexed: 12/16/2022]
Abstract
The non-specific adsorption of protein has caused many problems in the application of materials. In this paper, a tri-block copolymer PEO-PNIPAAm-PSPMAP with double effects were obtained via atom transfer radical copolymerization (ATRP). The double-effect copolymer is covalently bonded to the hydrophobic material through a photosensitizer to achieve surface modification and applied to analytical chemistry. Sufficient hydratable groups (for instance, ether bonds, amide groups, and sulfonic acid groups) in the copolymer provides a basis for the anti-protein adsorption. At the same time, the interaction of the hydrophilic group and isopropyl group with temperature changes provides the possibility of elastic self-cleaning of the material, which is instrumental in extending the circulate lifetime of materials. Therefore, it is an environmentally friendly coating material. Besides, the effective antifouling performance and elastic self-cleaning function of the coating have been confirmed by the dynamic adsorption experiment of a fluorescent protein. The coating is used in capillary electrophoresis (CE), and its excellent protein separation spectrum verifies the practicality of the coating.
Collapse
Affiliation(s)
- Fang Wang
- Institute of Biomedical Materials and Engineering, College of Chemistry and Chemical Engineering, College of Materials Science and Engineering, Affiliated Hospital of Qingdao University, Qingdao University, Qingdao, 266071, China
| | - Hailin Cong
- Institute of Biomedical Materials and Engineering, College of Chemistry and Chemical Engineering, College of Materials Science and Engineering, Affiliated Hospital of Qingdao University, Qingdao University, Qingdao, 266071, China; State Key Laboratory of Bio-Fibres and Eco-Textiles, Qingdao University, Qingdao, 266071, China
| | - Jie Xing
- Institute of Biomedical Materials and Engineering, College of Chemistry and Chemical Engineering, College of Materials Science and Engineering, Affiliated Hospital of Qingdao University, Qingdao University, Qingdao, 266071, China
| | - Song Wang
- Institute of Biomedical Materials and Engineering, College of Chemistry and Chemical Engineering, College of Materials Science and Engineering, Affiliated Hospital of Qingdao University, Qingdao University, Qingdao, 266071, China
| | - Youqing Shen
- Institute of Biomedical Materials and Engineering, College of Chemistry and Chemical Engineering, College of Materials Science and Engineering, Affiliated Hospital of Qingdao University, Qingdao University, Qingdao, 266071, China; Centre for Bio Nanoengineering and Key Laboratory of Biomass Chemical Engineering of Ministry of Education, College of Chemical and Biological Engineering, Zhejiang University, Hangzhou, 310027, China
| | - Bing Yu
- Institute of Biomedical Materials and Engineering, College of Chemistry and Chemical Engineering, College of Materials Science and Engineering, Affiliated Hospital of Qingdao University, Qingdao University, Qingdao, 266071, China; State Key Laboratory of Bio-Fibres and Eco-Textiles, Qingdao University, Qingdao, 266071, China.
| |
Collapse
|
21
|
Stolz A, Hedeland Y, Salzer L, Römer J, Heiene R, Leclercq L, Cottet H, Bergquist J, Neusüß C. Capillary Zone Electrophoresis-Top-Down Tandem Mass Spectrometry for In-Depth Characterization of Hemoglobin Proteoforms in Clinical and Veterinary Samples. Anal Chem 2020; 92:10531-10539. [PMID: 32628011 DOI: 10.1021/acs.analchem.0c01350] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Hemoglobin (Hb) constitutes an important protein in clinical diagnostics-both in humans and animals. Among the high number of sequence variants, some can cause severe diseases. Moreover, chemical modifications such as glycation and carbamylation serve as important biomarkers for conditions such as diabetes and kidney diseases. In clinical routine analysis of glycated Hb, sequence variants or other Hb proteoforms can cause interference, resulting in wrong quantification results. We present a versatile and flexible capillary zone electrophoresis-mass spectrometry screening method for Hb proteoforms including sequence variants and modified species extracted from dried blood spot (DBS) samples with virtually no sample preparation. High separation power was achieved by application of a 5-layers successive multiple ionic polymer layers-coated capillary, enabling separation of positional isomers of glycated α- and β-chains on the intact level. Quantification of glycated Hb was in good correlation with the results obtained in a clinical routine method. Identification and characterization of known and unknown proteoforms was performed by fragmentation of intact precursor ions. N-Terminal and lysine glycation could be identified on the α- and β-chain, respectively. The versatility of the method was demonstrated by application to dog and cat DBS samples. We discovered a putative new sequence variant of the β-chain in dog (T38 → A). The presented method enables separation, characterization, and quantification of intact proteoforms, including positional isomers of glycated species in a single run. Combined with the simple sample preparation, our method represents a valuable tool to be used for deeper characterization of clinical and veterinary samples.
Collapse
Affiliation(s)
- Alexander Stolz
- Department of Chemistry, Aalen University, Beethovenstraße 1, 73430 Aalen, Germany.,Department of Pharmaceutical and Medicinal Chemistry, Friedrich Schiller University Jena, 07743 Jena, Germany
| | - Ylva Hedeland
- Department of Medical Sciences, Clinical Chemistry, , Uppsala University Hospital, SE-751 24 Uppsala, Sweden
| | - Liesa Salzer
- Department of Chemistry, Aalen University, Beethovenstraße 1, 73430 Aalen, Germany
| | - Jennifer Römer
- Department of Chemistry, Aalen University, Beethovenstraße 1, 73430 Aalen, Germany.,Institute of Analytical Chemistry, Chemo-and Biosensors,University of Regensburg, 93053 Regensburg, Germany
| | | | - Laurent Leclercq
- IBMM, University of Montpellier, CNRS, ENSCM, Beethovenstraße 1, 34090 Montpellier, France
| | - Hervé Cottet
- IBMM, University of Montpellier, CNRS, ENSCM, Beethovenstraße 1, 34090 Montpellier, France
| | - Jonas Bergquist
- Department of Chemistry -Biomedical Center, Analytical Chemistry, Uppsala University, SE-751 24 Uppsala, Sweden
| | - Christian Neusüß
- Department of Chemistry, Aalen University, Beethovenstraße 1, 73430 Aalen, Germany
| |
Collapse
|
22
|
Leclercq L, Renard C, Martin M, Cottet H. Quantification of Adsorption and Optimization of Separation of Proteins in Capillary Electrophoresis. Anal Chem 2020; 92:10743-10750. [DOI: 10.1021/acs.analchem.0c02012] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Affiliation(s)
- Laurent Leclercq
- IBMM, Université de Montpellier, CNRS, ENSCM, Montpellier 34095, France
| | - Charly Renard
- IBMM, Université de Montpellier, CNRS, ENSCM, Montpellier 34095, France
| | - Michel Martin
- PMMH, CNRS, ESPCI Paris − PSL, Sorbonne Université, Université de Paris, Paris 75005, France
| | - Hervé Cottet
- IBMM, Université de Montpellier, CNRS, ENSCM, Montpellier 34095, France
| |
Collapse
|
23
|
Kravchenko A, Kolobova E, Kartsova L. Multifunction covalent coatings for separation of amino acids, biogenic amines, steroid hormones, and ketoprofen enantiomers by capillary electrophoresis and capillary electrochromatography. SEPARATION SCIENCE PLUS 2020. [DOI: 10.1002/sscp.201900098] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Affiliation(s)
- Anastasia Kravchenko
- Saint Petersburg State UniversityInstitute of Chemistry 26 Universitetskii prospect St. Petersburg Peterhof 198504 Russia
| | - Ekaterina Kolobova
- Saint Petersburg State UniversityInstitute of Chemistry 26 Universitetskii prospect St. Petersburg Peterhof 198504 Russia
- The Federal State Institute of Public Health ‘The Nikiforov Russian Center of Emergency and Radiation Medicine’The Ministry of Russian Federation for Civil DefenceEmergencies and Elimination of Consequences of Natural Disasters 54, Optikov st. St. Petersburg 197082 Russia
| | - Liudmila Kartsova
- Saint Petersburg State UniversityInstitute of Chemistry 26 Universitetskii prospect St. Petersburg Peterhof 198504 Russia
| |
Collapse
|
24
|
Kristoff CJ, Bwanali L, Veltri LM, Gautam GP, Rutto PK, Newton EO, Holland LA. Challenging Bioanalyses with Capillary Electrophoresis. Anal Chem 2020; 92:49-66. [PMID: 31698907 PMCID: PMC6995690 DOI: 10.1021/acs.analchem.9b04718] [Citation(s) in RCA: 41] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Affiliation(s)
- Courtney J. Kristoff
- C. Eugene Bennett Department of Chemistry, West Virginia University, Morgantown, West Virginia 26506, United States
| | - Lloyd Bwanali
- C. Eugene Bennett Department of Chemistry, West Virginia University, Morgantown, West Virginia 26506, United States
| | - Lindsay M. Veltri
- C. Eugene Bennett Department of Chemistry, West Virginia University, Morgantown, West Virginia 26506, United States
| | - Gayatri P. Gautam
- C. Eugene Bennett Department of Chemistry, West Virginia University, Morgantown, West Virginia 26506, United States
| | - Patrick K. Rutto
- C. Eugene Bennett Department of Chemistry, West Virginia University, Morgantown, West Virginia 26506, United States
| | - Ebenezer O. Newton
- C. Eugene Bennett Department of Chemistry, West Virginia University, Morgantown, West Virginia 26506, United States
| | - Lisa A. Holland
- C. Eugene Bennett Department of Chemistry, West Virginia University, Morgantown, West Virginia 26506, United States
| |
Collapse
|
25
|
Hill N, Lapizco-Encinas BH. Continuous flow separation of particles with insulator-based dielectrophoresis chromatography. Anal Bioanal Chem 2020; 412:3891-3902. [DOI: 10.1007/s00216-019-02308-w] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2019] [Revised: 11/15/2019] [Accepted: 11/27/2019] [Indexed: 01/10/2023]
|
26
|
Kašička V. Recent developments in capillary and microchip electroseparations of peptides (2017–mid 2019). Electrophoresis 2019; 41:10-35. [DOI: 10.1002/elps.201900269] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2019] [Revised: 10/08/2019] [Accepted: 10/19/2019] [Indexed: 12/14/2022]
Affiliation(s)
- Václav Kašička
- Institute of Organic Chemistry and BiochemistryCzech Academy of Sciences Prague 6 Czechia
| |
Collapse
|
27
|
Ahmed MA, Felisilda BMB, Quirino JP. Recent advancements in open-tubular liquid chromatography and capillary electrochromatography during 2014-2018. Anal Chim Acta 2019; 1088:20-34. [PMID: 31623713 DOI: 10.1016/j.aca.2019.08.016] [Citation(s) in RCA: 49] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2019] [Revised: 06/28/2019] [Accepted: 08/07/2019] [Indexed: 12/20/2022]
Abstract
This review critically discusses the developments on open-tubular liquid chromatography (OT-LC) and open-tubular capillary electrochromatography (OT-CEC) during 2014-2018. An appropriate Scopus search revealed 5 reviews, 4 theoretical papers on open-tubular format chromatography, 29 OT-LC articles, 68 OT-CEC articles and 4 OT-LC/OT-CEC articles, indicating a sustained interest in these areas. The open-tubular format typically uses a capillary column with inner walls that are coated with an ample layer or coating of solid stationary phase material. The ratio between the capillary internal diameter and coating thickness (CID/CT) is ideally ≤ 100 for appropriate chromatographic retention. We, therefore, approximated the CID/CT ratios and found that 22 OT-LC papers have CID/CT ratios ≤100. The other 7 OT-LC papers have CID/CT ratio >100 but have clearly demonstrated chromatographic retention. These 29 papers utilised reversed phase or ion exchange mechanisms using known or innovative solid stationary phase materials (e.g. metal organic frameworks), stationary pseudophases from ionic surfactants or porous supports. On the other hand, we found that 68 OT-CEC papers, 7 OT-LC papers and 4 OT-LC & OT-CEC papers have CID/CT ratios >100. Notably, 44 papers (42 OT-CEC and 2 OT-LC & OT-CEC) did not report the retention factor and/or effective electrophoretic mobility of analytes. Considering all covered papers, the most popular activity was on the development of new chromatographic materials as coatings. However, we encourage OT-CEC researchers to not only characterise changes in the electroosmotic flow but also verify the interaction of the analytes with the coating. In addition, the articles reported were largely driven by stationary phase or support development and not by practical applications.
Collapse
Affiliation(s)
- Mohamed Adel Ahmed
- Australian Centre for Research on Separation Science (ACROSS), School of Natural Sciences, Chemistry, University of Tasmania, Hobart, 7001, Australia
| | - Bren Mark B Felisilda
- Australian Centre for Research on Separation Science (ACROSS), School of Natural Sciences, Chemistry, University of Tasmania, Hobart, 7001, Australia
| | - Joselito P Quirino
- Australian Centre for Research on Separation Science (ACROSS), School of Natural Sciences, Chemistry, University of Tasmania, Hobart, 7001, Australia.
| |
Collapse
|
28
|
Zhang H, Zhou DD, Yang FQ, Qian ZM, Li CH, Li WJ, Wang SP, Wang YT. Modulation of electroosmotic flow in capillary electrophoresis by plant polyphenol-inspired gallic acid/polyethyleneimine coatings: Analysis of small molecules. J Chromatogr B Analyt Technol Biomed Life Sci 2019; 1124:7-16. [PMID: 31176269 DOI: 10.1016/j.jchromb.2019.05.031] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2019] [Revised: 05/22/2019] [Accepted: 05/27/2019] [Indexed: 10/26/2022]
Abstract
Plant polyphenols can form functional coatings on various materials through self-polymerization. In this paper, a series of modified capillary columns, which possess diversity of charge characteristics for modulating electroosmotic flow (EOF), were prepared by one-step co-deposition of gallic acid (GA), a plant-derived polyphenol monomer, and branched polyethyleneimine (PEI). The physicochemical properties of the prepared columns were characterized by Fourier transform infrared spectroscopy (FT-IR), UV-Vis spectroscopy and scanning electron microscopy (SEM). The magnitude and direction of EOF of GA/PEI co-deposited columns were modulated by changing a series of coating parameters, such as post-incubation of FeCl3, co-deposition time, and deposited amounts of GA and PEI with different relative molecular mass (PEI-600, PEI-1800, PEI-10000, and PEI-70000). Furthermore, the separation efficiencies of the prepared GA/PEI co-deposited columns were evaluated by separations of small molecules, including organic acids, polar nucleotides, phenols, nucleic acid bases and nucleosides. Results indicated that modulating of EOF plays an important role in enhancing the separation performance and reversing the elution order of the analytes. Finally, the developed method was successfully applied to quantitative analysis of acidic compounds in four real samples. The recoveries were in the range of 73.5%-85.8% for citric acid, benzoic acid, sorbic acid, salicylic acid and ascorbic acid in beverage and fruit samples, 101.6%-104.9% for cinnamic acid, vanillic acid, and ferulic acid in Angelica sinensis sample, while 84.6%-97.8% for guanosine-5'-monophosphate, uridine-5'-monophosphate, cytosine-5'- monophosphate and adenosine-5'-monophosphate in Cordyceps samples. These results indicated that the co-deposition of plant polyphenol-inspired GA/PEI coatings can provide new opportunities for EOF modulation of capillary electrophoresis.
Collapse
Affiliation(s)
- Hao Zhang
- School of Chemistry and Chemical Engineering, Chongqing University, Chongqing 401331, China
| | - Dong-Dong Zhou
- School of Chemistry and Chemical Engineering, Chongqing University, Chongqing 401331, China
| | - Feng-Qing Yang
- School of Chemistry and Chemical Engineering, Chongqing University, Chongqing 401331, China.
| | - Zheng-Ming Qian
- Key Laboratory of State Administration of Traditional Chinese Medicine, Sunshine Lake Pharma Co., LTD, Dongguan, Guangdong 523850, China
| | - Chun-Hong Li
- Key Laboratory of State Administration of Traditional Chinese Medicine, Sunshine Lake Pharma Co., LTD, Dongguan, Guangdong 523850, China
| | - Wen-Jia Li
- Key Laboratory of State Administration of Traditional Chinese Medicine, Sunshine Lake Pharma Co., LTD, Dongguan, Guangdong 523850, China
| | - Sheng-Peng Wang
- State Key Laboratory of Quality Research in Chinese Medicine, Institute of Chinese Medical Sciences, University of Macau, Macao
| | - Yi-Tao Wang
- State Key Laboratory of Quality Research in Chinese Medicine, Institute of Chinese Medical Sciences, University of Macau, Macao.
| |
Collapse
|