1
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Puerta A, Garcia-Lopez D, Tejedor-Matellanes P, Gomez-Ruiz L, de la Cruz-Rodriguez R, de Frutos M. Capillary gel electrophoresis of very high molecular weight glycoproteins. Commercial and tailor-made gels for analysis of human monomeric and secretory immunoglobulin A. J Chromatogr A 2023; 1688:463689. [PMID: 36528901 DOI: 10.1016/j.chroma.2022.463689] [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: 07/14/2022] [Revised: 10/18/2022] [Accepted: 11/27/2022] [Indexed: 12/07/2022]
Abstract
Capillary gel electrophoresis (CGE) has been widely used for analysis of proteins according to their size. However, to our knowledge, this technique has not been optimized to immunoglobulin A (IgA) analysis, a protein of current and emerging high interest in several fields. IgA is the first barrier of human body against pathogens. This protein in human milk and colostrum is essential for immune protection of newborns and treatment of milk for storage in Human Milk Banks may alter IgA. The emerging use of IgA as therapeutic treatment also encourages the development of analysis methods for this class of immunoglobulins. IgA is far more heterogeneously glycosylated and complex than the well-studied IgG molecules. IgA in serum is mainly monomeric (mIgA) with about 160 kDa, while in secretions such as saliva, milk, colostrum, etc, secretory immunoglobulin A (sIgA) is the predominant form. This is a dimer where both monomers are linked by the J-chain and the secretory component accounting all together for a MW higher than 400 kDa including the glycans. This size is far from the 225 kDa MW for which commercial CGE kits are intended. The general rules governing CGE behavior of analytes cannot be directly applied to every protein. Addressing studies directed specifically to target proteins is specially needed for the large size and highly complex target analytes of this study. In this work the effect of several factors on CGE analysis of human serum and colostrum IgA is studied. The feasibility of performing analysis of both IgA classes using a commercial CGE kit is shown. In addition, this work introduces another novelty by preparing tailor-made reproducible gel buffers and to characterize them in terms of dynamic viscosity, conductivity, and electroosmotic flow mobility in bare fused silica capillaries. The possibility of analyzing mIgA and sIgA in less than 10 min using these tailor-made gels is demonstrated. Inter-day variation (RSD) for the main peak of sIgA is 0.25% for migration time (tm) and 0.27% for percentage corrected peak area (Acorr).
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Affiliation(s)
- Angel Puerta
- Institute of Organic Chemistry (IQOG-CSIC), Juan de la Cierva 3, E-28006 Madrid, Spain.
| | - Daniel Garcia-Lopez
- Institute of Organic Chemistry (IQOG-CSIC), Juan de la Cierva 3, E-28006 Madrid, Spain
| | | | - Laura Gomez-Ruiz
- Institute of Organic Chemistry (IQOG-CSIC), Juan de la Cierva 3, E-28006 Madrid, Spain
| | | | - Mercedes de Frutos
- Institute of Organic Chemistry (IQOG-CSIC), Juan de la Cierva 3, E-28006 Madrid, Spain
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2
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Zhou QY, Wang LJ, Liu Y, Zhong XY, Dong JH, Zhou YL, Zhang XX. Ultrasensitive Multiplex Detection of Single Nucleotide Polymorphisms Based on Short-Chain Hybridization Combined with Online Preconcentration of Capillary Electrophoresis. Anal Chem 2020; 92:10620-10626. [PMID: 32643365 DOI: 10.1021/acs.analchem.0c01675] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Reliable multiple single nucleotide polymorphisms (SNPs) detection at low abundance is of great significance for disease diagnosis and biomedical research. Herein, we have developed a novel and simple method for multiple SNPs detection combining solid-phase capture by specific hybridization with online preconcentration of capillary gel electrophoresis-laser-induced fluorescence (CGE-LIF). The method presents an excellent performance due to its favorable traits: the solid-phase short-chain hybridization ensures the high specificity of SNP detection; the effective separation ability of CGE can easily achieve multiplex detection; the simple online preconcentration significantly improves the detection sensitivity of fluorescent probe by nearly 100-fold. For a single SNP target, the assay achieves a limit of detection as low as 0.01-0.02% for three different NRAS mutations in the same codon. For multiple SNP targets, as low as 0.05% abundance can be easily realized. Our method is simple, efficient, ultrasensitive, and universal for multiple SNPs detection without complex enzymatic or chemical ligation reaction, which shows great potential in early clinical diagnosis.
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Affiliation(s)
- Qian-Yu Zhou
- Beijing National Laboratory for Molecular Sciences (BNLMS), MOE Key Laboratory of Bioorganic Chemistry and Molecular Engineering, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, China
| | - Li-Juan Wang
- Key Laboratory of Medical Chemistry and Molecular Diagnosis, Ministry of Education, Hebei University, Baoding, Hebei 071002, China
| | - Ying Liu
- Key Laboratory of Medical Chemistry and Molecular Diagnosis, Ministry of Education, Hebei University, Baoding, Hebei 071002, China
| | - Xin-Ying Zhong
- Beijing National Laboratory for Molecular Sciences (BNLMS), MOE Key Laboratory of Bioorganic Chemistry and Molecular Engineering, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, China
| | - Jia-Hui Dong
- Beijing National Laboratory for Molecular Sciences (BNLMS), MOE Key Laboratory of Bioorganic Chemistry and Molecular Engineering, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, China
| | - Ying-Lin Zhou
- Beijing National Laboratory for Molecular Sciences (BNLMS), MOE Key Laboratory of Bioorganic Chemistry and Molecular Engineering, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, China
| | - Xin-Xiang Zhang
- Beijing National Laboratory for Molecular Sciences (BNLMS), MOE Key Laboratory of Bioorganic Chemistry and Molecular Engineering, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, China
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3
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Zhang CX, Meagher MM. Highly Sensitive SDS Capillary Gel Electrophoresis with Sample Stacking Requiring Only Nanograms of Adeno-Associated Virus Capsid Proteins. Methods Mol Biol 2019; 1972:263-270. [PMID: 30847798 DOI: 10.1007/978-1-4939-9213-3_19] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) has been the method of choice in the past decades for size-based protein analysis. However, in general it requires the protein concentration in mg/mL level and thus is not practical for trace level protein analysis, not to mention the lengthy labor-intensive procedures. The SDS capillary gel electrophoresis (SDS CGE) method reported herein requires only nanogram-sized proteins loaded onto the autosampler. A sample stacking technique (e.g., head-column field-amplified sample stacking (HC FASS)) was employed, providing three orders of magnitude sensitivity enhancement compared to conventional SDS CGE. This method has been used routinely in purity analysis and characterization of adeno-associated virus (AAV) intermediates and finished gene therapeutics of AAV vectors. The sensitivity achieved is comparable to the currently most sensitive size-based protein assay silver-stained SDS PAGE. The highly sensitive sample stacking SDS CGE can be used for other types of proteins as well.
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Affiliation(s)
- Chao-Xuan Zhang
- Department of Therapeutics Production and Quality, St. Jude Children's Research Hospital, Memphis, TN, USA.
| | - Michael M Meagher
- Department of Therapeutics Production and Quality, St. Jude Children's Research Hospital, Memphis, TN, USA
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4
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Hou M, Zhang M, Chen L, Gong K, Pan C, Wang Y. Amplification of lysozyme signal detected in capillary electrophoresis using mixed polymer brushes coating with switchable properties. Talanta 2019; 202:426-435. [PMID: 31171204 DOI: 10.1016/j.talanta.2019.05.014] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2019] [Revised: 04/22/2019] [Accepted: 05/02/2019] [Indexed: 12/29/2022]
Abstract
In this work, a mixed polymer brushes based on poly(2-methyl-2-oxazoline) (PMOXA) and poly(acrylic acid) (PAA) coated capillary with switchable protein adsorption/desorption properties was developed and applied for on-line extraction and preconcentration of lysozyme. The study of electroosmotic flow (EOF) and fluorescence microscope showed that the inner surface charge of PMOXA/PAA mixed brush coated capillary displayed the switchable behavior toward the change of pH value and ionic strength (I), and PMOXA/PAA mixed brushes coated capillary could adsorb high amounts of lysozyme at pH 7 (I = 10-5 M), and the most of adsorbed lysozyme could then be desorbed at pH 3 (I = 10-1 M). Subsequently, this coated capillary with switchable lysozyme adsorption/desorption ability was applied for on-line extraction and preconcentration of lysozyme during capillary electrophoresis (CE) performance. Under the process of on-line preconcentration, the detection signal (peak area) of lysozyme obtained in PMOXA/PAA coated capillary was 26 times that obtained in bare capillary under normal CE while the contour chain length of PAA was 1.56 times that of PMOXA. Moreover, the value of low detection limit (LOD) of lysozyme using above coated capillary under on-line preconcentration method reached to 4.5 × 10-9 mg/mL, and 1 × 105-fold sensitivity enhancement was realized for lysozyme as compared with the bare capillary under normal CE.
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Affiliation(s)
- Mingxin Hou
- CAS Key Laboratory of Soft Matter Chemistry, Department of Polymer Science and Engineering, University of Science and Technology of China, Hefei, 230026, PR China
| | - Miao Zhang
- CAS Key Laboratory of Soft Matter Chemistry, Department of Polymer Science and Engineering, University of Science and Technology of China, Hefei, 230026, PR China
| | - Lijuan Chen
- CAS Key Laboratory of Soft Matter Chemistry, Department of Polymer Science and Engineering, University of Science and Technology of China, Hefei, 230026, PR China; Colllege of Materials and Chemical Engineering, West Anhui University, Luan, 237012, PR China
| | - Kai Gong
- CAS Key Laboratory of Soft Matter Chemistry, Department of Polymer Science and Engineering, University of Science and Technology of China, Hefei, 230026, PR China
| | - Chao Pan
- CAS Key Laboratory of Soft Matter Chemistry, Department of Polymer Science and Engineering, University of Science and Technology of China, Hefei, 230026, PR China
| | - Yanmei Wang
- CAS Key Laboratory of Soft Matter Chemistry, Department of Polymer Science and Engineering, University of Science and Technology of China, Hefei, 230026, PR China.
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5
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Ghiasvand A, Feng Z, Quirino JP. Enrichment and Separation of Cationic, Neutral, and Chiral Analytes by Micelle to Cyclodextrin Stacking–Micellar Electrokinetic Chromatography. Anal Chem 2018; 91:1752-1757. [DOI: 10.1021/acs.analchem.8b03542] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
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6
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Šesták J, Theurillat R, Sandbaumhüter FA, Thormann W. Fundamental aspects of field-amplified electrokinetic injection of cations for enantioselective capillary electrophoresis with sulfated cyclodextrins as selectors. J Chromatogr A 2018; 1558:85-95. [PMID: 29759647 DOI: 10.1016/j.chroma.2018.05.022] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2018] [Revised: 05/02/2018] [Accepted: 05/08/2018] [Indexed: 01/30/2023]
Abstract
Head-column field-amplified sample stacking of cations from a low conductivity sample followed by enantiomeric separation using negatively charged chiral selectors was studied experimentally and with computer simulation. Aspects investigated include the direct electrokinetic injection of the analytes into the background electrolyte, the use of a selector free buffer plug, the contribution of complexation within the buffer plug and the application of an additional water plug between sample and buffer plug. Attention was paid for changes of ionic strength which is known to have a significant impact on complexation and thus effective mobility. Racemic methadone was selected as a model compound, randomly substituted sulfated β-cyclodextrin as chiral selector and phosphate buffers (pH 6.3) for the background electrolyte and the buffer plug. Results confirm that the buffer plug is providing a spacer between cationic analytes and the negatively charged selector during electrokinetic injection. Simulation predicts the required length and composition of the plug for a given injection time to avoid an interference with the selector. A short water plug added between the low conductivity sample and a high conductivity buffer plug is demonstrated to provide best conditions to achieve high sensitivity in enantioselective drug assays with sulfated cyclodextrins as selectors.
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Affiliation(s)
- Jozef Šesták
- University of Bern, Clinical Pharmacology Laboratory, Institute for Infectious Diseases, Murtenstrasse 35, 3008 Bern, Switzerland; Institute of Analytical Chemistry of the Czech Academy of Sciences, Veveří 97, 602 00 Brno, Czechia
| | - Regula Theurillat
- University of Bern, Clinical Pharmacology Laboratory, Institute for Infectious Diseases, Murtenstrasse 35, 3008 Bern, Switzerland
| | - Friederike A Sandbaumhüter
- University of Bern, Clinical Pharmacology Laboratory, Institute for Infectious Diseases, Murtenstrasse 35, 3008 Bern, Switzerland
| | - Wolfgang Thormann
- University of Bern, Clinical Pharmacology Laboratory, Institute for Infectious Diseases, Murtenstrasse 35, 3008 Bern, Switzerland.
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7
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Zhang CX, Meagher MM. Sample Stacking Provides Three Orders of Magnitude Sensitivity Enhancement in SDS Capillary Gel Electrophoresis of Adeno-Associated Virus Capsid Proteins. Anal Chem 2017; 89:3285-3292. [DOI: 10.1021/acs.analchem.6b02933] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Affiliation(s)
- Chao-Xuan Zhang
- Department of Therapeutics
Production and Quality, St. Jude Children’s Research Hospital, Memphis, Tennessee 38105, United States
| | - Michael M. Meagher
- Department of Therapeutics
Production and Quality, St. Jude Children’s Research Hospital, Memphis, Tennessee 38105, United States
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8
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Forough M, Farhadi K, Molaei R, Khalili H, Shakeri R, Zamani A, Matin AA. Capillary electrophoresis with online stacking in combination with AgNPs@MCM-41 reinforced hollow fiber solid-liquid phase microextraction for quantitative analysis of Capecitabine and its main metabolite 5-Fluorouracil in plasma samples isolated from cancer patients. J Chromatogr B Analyt Technol Biomed Life Sci 2017; 1040:22-37. [DOI: 10.1016/j.jchromb.2016.11.025] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2016] [Revised: 11/10/2016] [Accepted: 11/16/2016] [Indexed: 12/12/2022]
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9
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A dispersive liquid-liquid microextraction and chiral separation of carvedilol in human plasma using capillary electrophoresis. Bioanalysis 2016; 7:1107-17. [PMID: 26039808 DOI: 10.4155/bio.15.51] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
BACKGROUND Development of simple, rapid and precise analysis of chiral drugs in biological samples is an important issue. Dispersive liquid-liquid microextraction in combination with CE using field amplified sample injection has been of interest because of its capability to analyze trace amount of drugs. METHODS Dispersive liquid-liquid microextraction-CE-field amplified sample injection was employed for chiral separation of carvedilol in human plasma using UV-DAD detector and the developed method has been validated according to US FDA method validation guideline for bioanalysis. RESULTS The method was linear over a concentration range of 12.5-100 ng/ml for each carvedilol enantiomer (R(2) = 0.998) and the mean recoveries ranged from 91 to 107%. CONCLUSION The method was adapted for sensitive, selective and rapid determination of carvedilol enantiomers in human plasma samples.
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10
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Theurillat R, Sandbaumhüter FA, Bettschart-Wolfensberger R, Thormann W. Microassay for ketamine and metabolites in plasma and serum based on enantioselective capillary electrophoresis with highly sulfated γ-cyclodextrin and electrokinetic analyte injection. Electrophoresis 2015; 37:1129-38. [DOI: 10.1002/elps.201500468] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2015] [Revised: 11/24/2015] [Accepted: 11/26/2015] [Indexed: 12/13/2022]
Affiliation(s)
- Regula Theurillat
- Clinical Pharmacology Laboratory; University of Bern; Bern Switzerland
| | | | | | - Wolfgang Thormann
- Clinical Pharmacology Laboratory; University of Bern; Bern Switzerland
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11
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Cheng HL, Tsai YH, Hsu WL, Lin YH. An on-line stacking capillary electrophoresis method for the analysis of Δ9-tetrahydrocannabinol and its metabolites. J Chromatogr A 2015; 1426:226-32. [DOI: 10.1016/j.chroma.2015.11.032] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2015] [Revised: 10/31/2015] [Accepted: 11/09/2015] [Indexed: 11/25/2022]
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12
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Gstoettenmayr D, Quirino J, Ivory CF, Breadmore M. Stacking in a continuous sample flow interface in capillary electrophoresis. J Chromatogr A 2015; 1408:236-42. [DOI: 10.1016/j.chroma.2015.06.040] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2015] [Revised: 06/05/2015] [Accepted: 06/16/2015] [Indexed: 10/23/2022]
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13
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Posch TN, Pütz M, Martin N, Huhn C. Electromigrative separation techniques in forensic science: combining selectivity, sensitivity, and robustness. Anal Bioanal Chem 2014; 407:23-58. [PMID: 25381613 DOI: 10.1007/s00216-014-8271-0] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2014] [Revised: 10/12/2014] [Accepted: 10/14/2014] [Indexed: 01/27/2023]
Abstract
In this review we introduce the advantages and limitations of electromigrative separation techniques in forensic toxicology. We thus present a summary of illustrative studies and our own experience in the field together with established methods from the German Federal Criminal Police Office rather than a complete survey. We focus on the analytical aspects of analytes' physicochemical characteristics (e.g. polarity, stereoisomers) and analytical challenges including matrix tolerance, separation from compounds present in large excess, sample volumes, and orthogonality. For these aspects we want to reveal the specific advantages over more traditional methods. Both detailed studies and profiling and screening studies are taken into account. Care was taken to nearly exclusively document well-validated methods outstanding for the analytical challenge discussed. Special attention was paid to aspects exclusive to electromigrative separation techniques, including the use of the mobility axis, the potential for on-site instrumentation, and the capillary format for immunoassays. The review concludes with an introductory guide to method development for different separation modes, presenting typical buffer systems as starting points for different analyte classes. The objective of this review is to provide an orientation for users in separation science considering using capillary electrophoresis in their laboratory in the future.
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Affiliation(s)
- Tjorben Nils Posch
- Forschungszentrum Jülich GmbH, Central Institute for Engineering, Electronics and Analytics, Analytics ZEA-3, 52425, Jülich, Germany
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14
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Yang X, Cheng X, Lin Y, Tan Z, Xie L, Choi MM. Determination of three nitroimidazoles in rabbit plasma by two-step stacking in capillary zone electrophoresis featuring sweeping and micelle to solvent stacking. J Chromatogr A 2014; 1325:227-33. [DOI: 10.1016/j.chroma.2013.11.053] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2013] [Revised: 11/26/2013] [Accepted: 11/27/2013] [Indexed: 11/27/2022]
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15
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Emara S, Masujima T, Zarad W, Mohamed K, Kamal M, Fouad M, EL-Bagary R. Field-amplified sample stacking β-cyclodextrin modified capillary electrophoresis for quantitative determination of diastereomeric saponins. J Chromatogr Sci 2013; 52:1308-16. [PMID: 24248558 DOI: 10.1093/chromsci/bmt169] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Successful simultaneous diastereomeric separation and sensitive determination of two pairs of triterpenoidal saponins have been achieved by capillary electrophoresis (CE) using β-cyclodextrin (β-CD) as a stereoselective agent to cooperate with borate complexation. A usual technique for isolation and group separation of saponins was developed as an appropriate purification step prior to the determination of individual saponins by CE. Soyasaponin I ( S1: ), azukisaponin V ( S2: ), bersimoside I ( S3: ) and bersimoside II ( S4: ) could be well separated within 14 min in a fused-silica capillary (60 cm long to the detector with an additional 10 cm to the cathode; 75 µm i.d.). The background electrolyte was borate buffer (80 mM, pH 10), containing 24 mM β-CD. The separation voltage was 14 kV with a detection wavelength of 195 nm. The sample was electrokinetically injected using a voltage of 16 kV for 12 s. Methanol (70%) was used as the diluent for field-amplified sample stacking after hydrodynamic injection of short water plug (5 cm, 4 s). The method was partially validated for linearity, repeatability, reproducibility, limits of detection and limits of quantification. The correlation coefficients of the calibration curves were all >0.998, and the recoveries were from 98.23 to 96.21%.
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Affiliation(s)
- Samy Emara
- Faculty of Pharmacy, Pharmaceutical Chemistry Department, Misr International University, Km 28 Ismailia Road, Cairo, Egypt
| | - Tsutomu Masujima
- P.I. Laboratory Single Cell MS, RIKEN Quantitative Biology Center, 6-2-3, Furuedai, Suita, Osaka 565-0874, Japan
| | - Walaa Zarad
- Faculty of Pharmacy, Pharmaceutical Chemistry Department, Misr International University, Km 28 Ismailia Road, Cairo, Egypt
| | - Khaled Mohamed
- Faculty of Pharmacy, Pharmacognosy Department, Assiut University, Assiut 71526, Egypt
| | - Maha Kamal
- Faculty of Pharmacy, Pharmaceutical Analytical Chemistry Department, Modern Sciences and Arts University, 26 July Mehwar Road Intersection with Wahat Road, 6 October City, Egypt
| | - Marwa Fouad
- Faculty of Pharmacy, Pharmaceutical Chemistry Department, Cairo University, Kasr El Aini St., Cairo 11562, Egypt
| | - Ramzia EL-Bagary
- Faculty of Pharmacy, Pharmaceutical Chemistry Department, Cairo University, Kasr El Aini St., Cairo 11562, Egypt
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16
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Abromeit H, Wu F, Scriba GKE. SPE of 5-lipoxygenase metabolites and the effect of head-column field-amplified sample stacking in MEKC. J Sep Sci 2013; 36:3592-8. [DOI: 10.1002/jssc.201300678] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2013] [Revised: 08/27/2013] [Accepted: 08/29/2013] [Indexed: 11/09/2022]
Affiliation(s)
- Hans Abromeit
- Department of Pharmaceutical/Medicinal Chemistry; Friedrich Schiller University Jena; Jena Germany
| | - Fengyi Wu
- Department of Pharmaceutical/Medicinal Chemistry; Friedrich Schiller University Jena; Jena Germany
- Key Laboratory of Combinatorial Biosynthesis and Drug Discovery; Wuhan University; Ministry of Education and School of Pharmaceutical Sciences; Wuhan PR China
| | - Gerhard K. E. Scriba
- Department of Pharmaceutical/Medicinal Chemistry; Friedrich Schiller University Jena; Jena Germany
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17
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Ito E, Nakajima K, Waki H, Miseki K, Shimada T, Sato TA, Kakehi K, Suzuki M, Taniguchi N, Suzuki A. Structural Characterization of Pyridylaminated Oligosaccharides Derived from Neutral Glycosphingolipids by High-Sensitivity Capillary Electrophoresis–Mass Spectrometry. Anal Chem 2013; 85:7859-65. [DOI: 10.1021/ac401460f] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Emi Ito
- Systems Glycobiology Research
Group, RIKEN−Max Planck Joint Research Center, Global Research
Cluster, RIKEN, 2-1 Hirosawa, Wako-shi,
Saitama 351-0198, Japan
| | - Kazuki Nakajima
- Systems Glycobiology Research
Group, RIKEN−Max Planck Joint Research Center, Global Research
Cluster, RIKEN, 2-1 Hirosawa, Wako-shi,
Saitama 351-0198, Japan
| | - Hiroaki Waki
- Analytical Division, Shimadzu Corporation, 1 Nishinokyo-Ku, Kuwabaracho,
Nakagyo-ku, Kyoto 604-8511, Japan
| | - Kozo Miseki
- Analytical Division, Shimadzu Corporation, 1 Nishinokyo-Ku, Kuwabaracho,
Nakagyo-ku, Kyoto 604-8511, Japan
| | - Takashi Shimada
- Life Science Research Center, Shimadzu Corporation, 5-1-1 Tsukiji, Chuo-ku, Tokyo
105-0045, Japan
| | - Taka-Aki Sato
- Life Science Research Center, Shimadzu Corporation, 5-1-1 Tsukiji, Chuo-ku, Tokyo
105-0045, Japan
| | - Kazuaki Kakehi
- School
of Pharmacy, Kinki University, 3-4-1 Kowakae,
Higashi-Osaka 577-8502,
Japan
| | - Minoru Suzuki
- Life Science Research Center, Shimadzu Corporation, 5-1-1 Tsukiji, Chuo-ku, Tokyo
105-0045, Japan
| | - Naoyuki Taniguchi
- Systems Glycobiology Research
Group, RIKEN−Max Planck Joint Research Center, Global Research
Cluster, RIKEN, 2-1 Hirosawa, Wako-shi,
Saitama 351-0198, Japan
| | - Akemi Suzuki
- Institute of Glycoscience, Tokai University, 4-1-1 Kitakaname, Hiratsuka, Kanagawa,
259-1292, Japan
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18
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Separation of 5-Lipoxygenase Metabolites Using Cyclodextrin-Modified Microemulsion Electrokinetic Chromatography and Head Column Field-Amplified Sample Stacking. Chromatographia 2013. [DOI: 10.1007/s10337-013-2517-4] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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19
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Hsieh SY, Wang CC, Wu SM. Microemulsion electrokinetic chromatography for analysis of phthalates in soft drinks. Food Chem 2013; 141:3486-91. [PMID: 23993511 DOI: 10.1016/j.foodchem.2013.06.023] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2012] [Revised: 04/05/2013] [Accepted: 06/06/2013] [Indexed: 02/05/2023]
Abstract
Microemulsion electrokinetic chromatography (MEEKC) is proposed for analysis of di-n-butyl phthalate (DBP) and di-(2-ethylhexyl) phthalate (DEHP) in soft drinks. However, the instability of microemulsion is a critical issue. In this research, a novel material, Pluronic® F-127, which has the properties of polymer and surfactant, was added for stabilizing the microemulsion in the MEEKC system. Our data demonstrate that the presence of Pluronic® F-127 (0.05-0.30%) also helps enhance resolution of highly hydrophobic compounds, DBP and DEHP. The electrokinetic injection of sodium dodecyl sulphate (SDS) including sample (-10 kV, 20 s) was introduced in this MEEKC system and this yielded about 25-fold sensitivity enhancement compared with hydrodynamic injection (1 psi, 10 s). During method validation, calibration curves were linear (r≥0.99), within a range of 75-500 ng/mL for DBP and 150-1000 ng/mL for DEHP. As the precision and accuracy assays, absolute values of relative standard deviation (RSD) and relative error (RE) in intraday (n=3) and interday (n=5) observations were less than 4.93%. This method was further applied for analyzing six commercial soft drinks and one was found containing 453.67 ng/mL of DEHP. This method is considered feasible for serving as a tool for analysis of highly hydrophobic molecules.
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Affiliation(s)
- Sung-Yu Hsieh
- School of Pharmacy, College of Pharmacy, Kaohsiung Medical University, Taiwan
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20
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Dong YM, Chien KY, Chen JT, Lin SJ, Wang TCV, Yu JS. Site-specific separation and detection of phosphopeptide isomers with pH-mediated stacking capillary electrophoresis-electrospray ionization-tandem mass spectrometry. J Sep Sci 2013; 36:1582-9. [PMID: 23494885 DOI: 10.1002/jssc.201300054] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2013] [Revised: 03/02/2013] [Accepted: 03/04/2013] [Indexed: 01/30/2023]
Abstract
This study reported a pH-mediated stacking CE coupled with ESI MS/MS method to determine the phosphorylation sites of three synthetic phosphopeptides containing structural isomers. These phosphopeptides mimic the phosphopeptides (amino acid residues 12-25) derived from the trypsin-digested products of human lamin A/C protein. The LODs were determined to be 118, 132 and 1240 fmol for SGAQASS(19)TpPL(22)SPTR, SGAQASS(19)TPL(22)SpPTR, and SGAQASS(19)TpPL(22)SpPTR, respectively. The established method was employed to analyze the phosphorylation sites of the trypsin-digested products of glutathione S-transferase-lamin A/C (1-57) fusion protein that had been phosphorylated in vitro by cyclin-dependent kinase 1. The results indicated that this method is feasible to specifically determine the phosphorylation site from phosphopeptide isomers in the trypsin-digested products of a kinase-catalyzed phosphoprotein, which should benefit the investigation of protein kinase-mediated cellular signal transduction.
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Affiliation(s)
- Yu-Ming Dong
- School of Pharmacy, Lanzhou University, PR China
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21
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Breadmore MC. Approaches to enhancing the sensitivity of carbohydrate separations in capillary electrophoresis. Methods Mol Biol 2013; 984:27-43. [PMID: 23386334 DOI: 10.1007/978-1-62703-296-4_3] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
Electrophoresis in both capillaries (CE) and microchips (ME) is an extremely powerful liquid phase-separation technique that is indispensable for the separation of carbohydrates. It is capable of separating both small mono- and disaccharides, through to more complex oligo- and polysaccharides, with high resolution, but as with all CE and ME separations, the detection limits are often inferior to those that can be achieved with liquid chromatographic methods. One avenue to address this is to use an on-line concentration strategy. Various approaches have been developed over the past 20 years, and this chapter will highlight their application to improve the sensitivity of carbohydrate separations in both CE and ME.
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Affiliation(s)
- M C Breadmore
- Australian Center for Research on Separation Science, School of Chemistry, University of Tasmania, Hobart, TAS, Australia.
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22
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Wang CC, Cheng SF, Cheng HL, Chen YL. Analysis of anabolic androgenic steroids in urine by full-capillary sample injection combined with a sweeping CE stacking method. Anal Bioanal Chem 2012; 405:1969-76. [DOI: 10.1007/s00216-012-6640-0] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2012] [Revised: 11/08/2012] [Accepted: 12/07/2012] [Indexed: 11/24/2022]
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23
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Abromeit H, Schaible AM, Werz O, Scriba GK. Chemometrics-guided development of a cyclodextrin-modified micellar electrokinetic chromatography method with head-column field amplified sample stacking for the analysis of 5-lipoxygenase metabolites. J Chromatogr A 2012; 1267:217-23. [DOI: 10.1016/j.chroma.2012.08.001] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2012] [Revised: 07/25/2012] [Accepted: 08/01/2012] [Indexed: 11/25/2022]
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24
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Wang CC, Chen JL, Chen YL, Cheng HL, Wu SM. A novel stacking method of repetitive large volume sample injection and sweeping MEKC for determination of androgenic steroids in urine. Anal Chim Acta 2012; 744:99-104. [DOI: 10.1016/j.aca.2012.07.021] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2012] [Revised: 07/11/2012] [Accepted: 07/13/2012] [Indexed: 12/22/2022]
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25
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Cheng YC, Wang CC, Chen YL, Wu SM. Large volume sample stacking with EOF and sweeping in CE for determination of common preservatives in cosmetic products by chemometric experimental design. Electrophoresis 2012; 33:1443-8. [DOI: 10.1002/elps.201100546] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Affiliation(s)
- Yi-Cian Cheng
- School of Pharmacy; College of Pharmacy; Kaohsiung Medical University; Kaohsiung; Taiwan
| | - Chun-Chi Wang
- School of Pharmacy; College of Pharmacy; Kaohsiung Medical University; Kaohsiung; Taiwan
| | - Yen-Ling Chen
- Department of Fragrance and Cosmetic Science; College of Pharmacy; Kaohsiung Medical University; Kaohsiung; Taiwan
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26
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Anres P, Delaunay N, Vial J, Gareil P. A chemometric approach for the elucidation of the parameter impact in the hyphenation of field-enhanced sample injection and sweeping in capillary electrophoresis. Electrophoresis 2012; 33:1169-81. [DOI: 10.1002/elps.201100483] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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27
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Lee SC, Wang CC, Yang PC, Wu SM. Enantioseparation of (±)-threo-methylphenidate in human plasma by cyclodextrin-modified sample stacking capillary electrophoresis. J Chromatogr A 2012; 1232:302-5. [DOI: 10.1016/j.chroma.2011.10.072] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2011] [Revised: 10/26/2011] [Accepted: 10/27/2011] [Indexed: 11/29/2022]
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28
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Wang Q, Zhang Y, Ding H, Wu J, Wang L, Zhou L, Pu Q. The use of ethylene glycol solution as the running buffer for highly efficient microchip-based electrophoresis in unmodified cyclic olefin copolymer microchips. J Chromatogr A 2011; 1218:9422-7. [PMID: 22099226 DOI: 10.1016/j.chroma.2011.10.078] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2011] [Revised: 10/25/2011] [Accepted: 10/27/2011] [Indexed: 11/18/2022]
Abstract
An ethylene glycol solution was used as the electrophoretic running buffer in unmodified cyclic olefin copolymer (COC) microchips to minimize the interactions between the analytes and the hydrophobic walls of the plastic microchannels, enhance the resolution of the analytes and eliminate the uncontrollable dispersion caused by uneven liquid levels and non-uniform surfaces of the separation channels. Five amino acids that were labeled with fluorescein isothiocyanate (FITC) were used as model analytes to examine the separation efficiency. The effects of ethylene glycol concentration, pH and sodium tetraborate concentration were systematically investigated. The five FITC-labeled amino acids were effectively resolved using a COC microchip with an effective length of 2.5 cm under optimum conditions, which included using a running buffer of 20 mmol/L sodium tetraborate in ethylene glycol:water (80:20, v/v), pH 6.7. A theoretical plate number of 4.8 × 10(5)/m was obtained for aspartic acid. The system exhibited good repeatability, and the relative standard deviations (n=5) of the peak areas and migration times were no more than 3.4% and 0.7%, respectively. Furthermore, the system was successfully applied to elucidate these five amino acids in human saliva.
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Affiliation(s)
- Qin Wang
- Key Laboratory of Nonferrous Metals Chemistry and Resources Utilization, Gansu Province, Sate Key Laboratory of Applied Organic Chemistry, Department of Chemistry, Lanzhou University, 222 Southern Tianshui Road, Lanzhou, Gansu 730000, China
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29
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Wang H, Lu Y, Chen J, Li J, Liu S. Subcritical water extraction of alkaloids in Sophora flavescens Ait. and determination by capillary electrophoresis with field-amplified sample stacking. J Pharm Biomed Anal 2011; 58:146-51. [PMID: 21996061 DOI: 10.1016/j.jpba.2011.09.014] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2011] [Revised: 09/16/2011] [Accepted: 09/18/2011] [Indexed: 11/26/2022]
Abstract
The extraction and determination of cytisine, sophocarpine, matrine, sophoridine and oxymatrine in Sophora flavescens Ait. were performed using subcritical water extraction and capillary electrophoresis with field-amplified sample stacking. The effects of extraction temperature, pressure, time and cycle number on the extraction yields were investigated systematically for accelerated solvent extraction with ethanol (ASE) and accelerated solvent extraction with water (subcritical water extraction, SWE). The extraction yields obtained using SWE, ASE, water ultrasonic extraction and chloroform soaking extraction methods were compared. The electrophoresis separation buffer was monosodium phosphate (pH 3.0; 110 mM)-isopropanol (85:15, v/v). The effect of phosphoric acid added to the sample matrix on the reproducibility of the peak heights of the analytes was also examined. Cytisine, sophoridine and oxymatrine showed good linearity (R(2)>0.999) within 0.125-4.0 μg/mL, and sophocarpine and matrine exhibited good linearity (R(2)>0.998) within 0.0625-2.0 μg/mL, with the detection limits in the range of 0.004-0.0013 μg/mL. The five alkaloid contents in medicinal plants from different sources and Sophora instant granule were determined and compared.
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Affiliation(s)
- Haiyan Wang
- College of Science, Northwest A&F University, No. 3 Taicheng Road, Yangling, Shaanxi 712100, China
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30
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Claude B, Nehmé R, Morin P. Analysis of urinary neurotransmitters by capillary electrophoresis: Sensitivity enhancement using field-amplified sample injection and molecular imprinted polymer solid phase extraction. Anal Chim Acta 2011; 699:242-8. [DOI: 10.1016/j.aca.2011.05.014] [Citation(s) in RCA: 59] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2011] [Revised: 05/02/2011] [Accepted: 05/09/2011] [Indexed: 10/18/2022]
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31
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Recent advances in the analysis of carbohydrates for biomedical use. J Pharm Biomed Anal 2011; 55:702-27. [DOI: 10.1016/j.jpba.2011.02.003] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2010] [Revised: 02/03/2011] [Accepted: 02/04/2011] [Indexed: 02/06/2023]
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32
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Lau HF, Quek NM, Law WS, Zhao JH, Hauser PC, Li SFY. Optimization of separation of heavy metals by capillary electrophoresis with contactless conductivity detection. Electrophoresis 2011; 32:1190-4. [DOI: 10.1002/elps.201000603] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2010] [Revised: 01/09/2011] [Accepted: 01/09/2011] [Indexed: 11/10/2022]
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33
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Zhu HD, Ren CL, Hu SQ, Zhou XM, Chen HL, Chen XG. Thousand fold concentration of an alkaloid in capillary zone electrophoresis by micelle to solvent stacking. J Chromatogr A 2011; 1218:733-8. [DOI: 10.1016/j.chroma.2010.11.060] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2010] [Revised: 11/19/2010] [Accepted: 11/24/2010] [Indexed: 10/18/2022]
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34
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Rapid analysis of melamine in infant formula by sweeping-micellar electrokinetic chromatography. J Chromatogr A 2009; 1216:8296-303. [DOI: 10.1016/j.chroma.2009.06.008] [Citation(s) in RCA: 60] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2009] [Revised: 05/28/2009] [Accepted: 06/02/2009] [Indexed: 11/21/2022]
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35
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Pan Q, Zhao M, Liu S. Combination of on-chip field amplification and bovine serum albumin sweeping for ultrasensitive detection of green fluorescent protein. Anal Chem 2009; 81:5333-41. [PMID: 19492801 DOI: 10.1021/ac9007607] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
We report a highly effective on-chip preconcentration method by combining field-amplified sample injection (FASI) and bovine serum albumin (BSA) sweeping for ultrasensitive detection of green fluorescent protein (GFP) on a simple cross-channel microchip device. With the formation of a stagnant sample/running buffer boundary by balancing the hydrodynamic flow and the electro-osmotic flow (EOF), GFP molecules can be continuously injected into the sample loading channel and stacked. We have also demonstrated that BSA is a very effective pseudo-stationary phase for sweeping concentration of proteins in comparison to the commonly used micelles. The combination of FASI and BSA sweeping yields a concentration factor of 3570 and a limit of detection of 8.4 pM for GFP. Using this method, we have separated GFP and GFP-insulin-like growth factor-I (GFP-IGF-I) fusion protein. The entire assay (GFP concentration, matrix elimination, and electrophoretic separation) can be completed within <5 min. Furthermore, we have successfully applied this method for the detection of GFP expression of E. coli cells and the GFP content in single E. coli cells.
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Affiliation(s)
- Qiong Pan
- Key Laboratory of Bioorganic Chemistry & Molecular Engineering of Ministry of Education, College of Chemistry and Molecular Engineering, Peking University, Beijing, 100871, People's Republic of China
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36
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On-line sample stacking of peptides in capillary electrophoresis for the study of prebiotic reactions between alpha,alpha-dialkylated amino acids and amino acid N-carboxyanhydrides. J Chromatogr A 2009; 1216:5748-54. [PMID: 19539298 DOI: 10.1016/j.chroma.2009.06.010] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2009] [Revised: 05/20/2009] [Accepted: 06/03/2009] [Indexed: 11/23/2022]
Abstract
The reaction between alpha,alpha-dialkylated amino acids and amino acid N-carboxyanhydrides is slow leading to low concentrations of products (peptides). The detection by capillary electrophoresis of the analytes contained in such samples is therefore a challenging issue. In this work, on-line sample pre-concentration methods based on field-amplified sample stacking have been implemented and compared. Because of the high ionic strength present in the sample matrix, samples were diluted with an organic solvent prior to analysis to decrease the sample conductivity. Different modes of sample injection (field amplified sample injection (FASI), hydrodynamic normal sample stacking (NSS) or large volume sample stacking (LVSS)) were compared. Pre-concentration factors of 20 for FASI, about 30-40 for NSS and 60 for LVSS were obtained for the analysis of (l,l) dipeptide of valine in a large excess of isovaline and 0.2M of ionic strength. For LVSS application and resolution optimisation, a new non-covalent coating based on the partial modification of the capillary surface was used to tune the electroosmotic flow magnitude and to pump the sample matrix out of the capillary. This on-line sample pre-concentration step allowed confirming that oligopeptides including alpha,alpha-dialkylated amino acids are formed during the reaction between alpha,alpha-dialkylated amino acids and N-carboxyanhydride amino acids.
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37
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Kartsova LA, Bessonova EA. Preconcentration techniques in capillary electrophoresis. JOURNAL OF ANALYTICAL CHEMISTRY 2009. [DOI: 10.1134/s1061934809040029] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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38
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Zhang J, Cui H, Xu L, Zhang L, Chen G. Analysis of aliphatic amines using head-column field-enhanced sample stacking in MEKC with LIF detection. Electrophoresis 2009; 30:674-81. [DOI: 10.1002/elps.200800569] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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39
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Yamamoto S, Hirakawa S, Suzuki S. In situ fabrication of ionic polyacrylamide-based preconcentrator on a simple poly(methyl methacrylate) microfluidic chip for capillary electrophoresis of anionic compounds. Anal Chem 2008; 80:8224-30. [PMID: 18841941 DOI: 10.1021/ac801245n] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
A simple and efficient method was developed for fabrication of an anionic sample preconcentrator on a channel of a commercial poly(methyl methacrylate) (PMMA)-made microchip using no photolithography or etching technique. The originality of our preconcentrator is based on simple photochemical copolymerization of monomers using the following procedure: All channels of the PMMA-made microchip were filled with gel solution comprising acrylamide, N,N'-methylene-bisacrylamide, and 2-acrylamide-2-methylpropanesulfonic acid with riboflavin as a photocatalytic initiator. In situ polymerization near the cross of the sample outlet channel was performed by irradiation with an argon ion laser beam, which is also used as the light source for fluorometric detection. The electrokinetic property and electric repulsion between sample components and anionic groups on the polyacrylamide gel layer produce, trap, and concentrate anions within a few minutes at the interface of the cathodic side of the gel layer. This method displays concentration factors as high as 10 (5). The availability of ionic preconcentrator was demonstrated by applying sensitive analysis of oligosaccharides labeled with 8-aminopyrene-1,3,6-trisulfonate and some glycoproteins labeled with fluorescein isothiocyanate under various buffer systems.
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Affiliation(s)
- Sachio Yamamoto
- School of Pharmacy, Kinki University, 3-4-1, Kowakae, Higashi-osaka, Japan
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40
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Huang L, Lin JM, Yu L, Xu L, Chen G. Field-amplified on-line sample stacking for simultaneous enantioseparation and determination of some β-blockers using capillary electrophoresis. Electrophoresis 2008; 29:3588-94. [DOI: 10.1002/elps.200700811] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
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41
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Improvement of Porous Electro-conductive Membrane Preparation and Its Application in Sample Injection Pre-concentration in the Capillary Electrophoresis of Proteins. CHINESE JOURNAL OF ANALYTICAL CHEMISTRY 2008. [DOI: 10.1016/s1872-2040(08)60047-x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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42
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Ali I, Gupta V, Aboul‐Enein HY, Hussain A. Hyphenation in sample preparation: Advancement from the micro to the nano world. J Sep Sci 2008; 31:2040-53. [DOI: 10.1002/jssc.200800123] [Citation(s) in RCA: 93] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
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43
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Dawod M, Breadmore MC, Guijt RM, Haddad PR. Electrokinetic supercharging for on-line preconcentration of seven non-steroidal anti-inflammatory drugs in water samples. J Chromatogr A 2008; 1189:278-84. [DOI: 10.1016/j.chroma.2007.12.056] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2007] [Revised: 12/07/2007] [Accepted: 12/12/2007] [Indexed: 10/22/2022]
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44
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Tagliaro F, Bortolotti F. Recent advances in the applications of CE to forensic sciences (2005–2007). Electrophoresis 2008; 29:260-8. [DOI: 10.1002/elps.200700708] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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45
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LIU X, ZHANG J, CHEN X. Online Concentration by Head-column Field-amplified with Large-volume Sample Stacking Using Flow Injection-Capillary Electrophoresis for the Analysis of Four Active Components in Cold Medicines. ANAL SCI 2008; 24:1031-7. [DOI: 10.2116/analsci.24.1031] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Affiliation(s)
- Xiumei LIU
- Department of Chemistry, Lanzhou University
| | | | - Xingguo CHEN
- Department of Chemistry, Lanzhou University
- State Key Laboratory of Applied Organic Chemistry, Lanzhou University
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46
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Du Y, Jia L, Liu H, Xing D. Comparison of On‐Line Concentration Methods in Capillary Zone Electrophoresis for Analysis of Water‐Soluble Vitamins. ANAL LETT 2007. [DOI: 10.1080/00032710701486199] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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47
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Gottardo R, Bortolotti F, De Paoli G, Pascali JP, Miksík I, Tagliaro F. Hair analysis for illicit drugs by using capillary zone electrophoresis-electrospray ionization-ion trap mass spectrometry. J Chromatogr A 2007; 1159:185-9. [PMID: 17240388 DOI: 10.1016/j.chroma.2007.01.011] [Citation(s) in RCA: 58] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2006] [Revised: 11/13/2006] [Accepted: 01/05/2007] [Indexed: 10/23/2022]
Abstract
In forensic toxicology, hair analysis has become a well established analytical strategy to investigate retrospectively drug abuse histories. In this field, gas chromatography-mass spectrometry and high-performance liquid chromatography-mass spectrometry are currently used, often after preliminary screening with immunoassays. However, on the basis of previous applications to pharmaceutical analysis, capillary zone electrophoresis coupled to ion trap mass spectrometry looks also highly promising. The purpose of the present work was the development of a simple and rapid CZE-MS method for sensitive and quantitative determination of the main drugs of abuse and their metabolites (namely, 6-monoacetylmorphine, morphine, amphetamine, methamphetamine, 3,4-methylenedioxyamphetamine (MDA), 3,4-methylenedioxymethampthetamine (MDMA), benzoylecgonine, ephedrine and cocaine) in human hair. Hair samples (100 mg) were washed, cut and incubated overnight in 0.1 M HCl at 45 degrees C, then neutralized with NaOH and extracted by a liquid-liquid extraction method. CZE separations were carried out in a 100 cm x 75 microm (I.D.) uncoated fused silica capillary. The separation buffer was composed of 25 mM ammonium formate, pH 9.5; the separation voltage was 15 kV. Electrokinetic injections were performed at 7 kV for 30 s under field amplified sample stacking conditions. ESI-ion trap MS detection was performed in the ESI positive ionization mode using the following conditions: capillary voltage 4 kV, nebulizer gas (nitrogen) pressure 3psi, source temperature 150 degrees C and drying gas (nitrogen) flow rate 8l/min. A sheath liquid, composed of isopropanol-water (50:50, v/v) with 0.5% formic acid, was delivered at a flow rate of 4 microl/min. The ion trap MS operated in a selected ion monitoring mode (SIM) of positive molecular ions for each drug/metabolite. Collision induced fragmentation was also possible. Nalorphine was used as internal standard. Under the described conditions, the separation of all compounds, except amphetamine/methamphetamine, MDA/MDMA and morphine/6-MAM was achieved in 20 min, with limits of detection lower than the most severe cut-offs adopted in hair analysis (i.e. 0.1 ng/mg). Linearity was assessed within drug concentration ranges from 0.025 to 5 ng of each analyte/mg of hair. Analytical precision was fairly acceptable with RSD's < or = 3.06% for migration times and < or = 22.47% for areas in real samples, in both intra-day and day-to-day experiments. On these grounds, the described method can be proposed for rapid, selective and accurate toxicological hair analysis for both clinical and forensic purposes.
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Affiliation(s)
- Rossella Gottardo
- Department of Medicine and Public Health, Unit of Forensic Medicine, University of Verona, Verona, Italy
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48
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Tagliaro F, Bortolotti F, Pascali JP. Current role of capillary electrophoretic/electrokinetic techniques in forensic toxicology. Anal Bioanal Chem 2007; 388:1359-64. [PMID: 17572886 DOI: 10.1007/s00216-007-1381-1] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2007] [Revised: 05/21/2007] [Accepted: 05/22/2007] [Indexed: 11/29/2022]
Abstract
The current application of capillary electrophoresis in forensic toxicology has been critically reviewed with special focus on the areas where this technique has shown real advantages over chromatographic methods. For example, capillary electrophoresis has been most successfully applied to the chiral analysis of some drugs of forensic interest, including amphetamines and their congeners. Another typical application field of capillary electrophoresis is represented by protein analysis. Recently, special interest has been paid to carbohydrate deficient transferrin (CDT), the most important biological marker of chronic alcohol abuse. Other specific applications of capillary electrophoresis of potential forensic toxicological concern are also discussed. The review includes 62 references.
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Affiliation(s)
- Franco Tagliaro
- Department of Medicine and Public Health, Section of Forensic Medicine, University of Verona, Policlinico G.B. Rossi, P.le L.A. Scuro, 37134 Verona, Italy.
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49
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Chen Z, Megharaj M, Naidu R. Confirmation of iron complex formation using electrospray ionization mass spectrometry (ESI-MS) and sample stacking for analysis of iron polycarboxylate speciation by capillary electrophoresis. Microchem J 2007. [DOI: 10.1016/j.microc.2006.12.001] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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50
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Breadmore MC. Recent advances in enhancing the sensitivity of electrophoresis and electrochromatography in capillaries and microchips. Electrophoresis 2007; 28:254-81. [PMID: 17149782 DOI: 10.1002/elps.200600463] [Citation(s) in RCA: 160] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
Poor sensitivity is considered to be one of the major limitations of electrophoretic separation methods, particularly when compared to traditional liquid chromatographic techniques. To address this issue, various in-line preconcentration techniques have been developed over the past 15 years, ranging in power and complexity, and there are now a number of well understood approaches routinely capable of providing a 10,000- to 100,000-fold increase in sensitivity, as well as several that can be pushed above a million. Furthermore, these have been achieved with particularly troublesome and often difficult samples, such as those having high salinity from a biological or environmental origin. This review will discuss the most common methods for improving the sensitivity of CE, CEC and microchip version of these, with particular attention to those approaches developed over the last five years.
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Affiliation(s)
- Michael C Breadmore
- Australian Centre for Research on Separation Science, School of Chemistry, University of Tasmania, Hobart, Tasmania, Australia.
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