1
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Recent advances in vitamins analysis by capillary electrophoresis. J Pharm Biomed Anal 2018; 147:278-287. [DOI: 10.1016/j.jpba.2017.07.030] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2017] [Revised: 07/06/2017] [Accepted: 07/26/2017] [Indexed: 12/18/2022]
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2
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Li T, Wu Z, Qin W. Integration of capillary electrophoresis with gold nanoparticle-based colorimetry. Anal Chim Acta 2017; 995:114-121. [DOI: 10.1016/j.aca.2017.09.014] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2017] [Revised: 08/29/2017] [Accepted: 09/03/2017] [Indexed: 12/18/2022]
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3
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Wang Z, He C, Peng Y, Chen F, Xiao P. Origins, Phytochemistry, Pharmacology, Analytical Methods and Safety of Cortex Moutan (Paeonia suffruticosa Andrew): A Systematic Review. Molecules 2017; 22:E946. [PMID: 28590441 PMCID: PMC6152737 DOI: 10.3390/molecules22060946] [Citation(s) in RCA: 48] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2017] [Revised: 06/02/2017] [Accepted: 06/03/2017] [Indexed: 11/17/2022] Open
Abstract
Cortex Moutan (CM), a well-known traditional Chinese medicine, is commonly used for treating various diseases in China and other eastern Asian countries. Recorded in Pharmacopeias of several countries, CM is now drawing increasing attention and under extensive studies in various fields. Phytochemical studies indicate that CM contains many valuable secondary metabolites, such as monoterpene glycosides and phenols. Ample evidence from pharmacological researches suggest that CM has a wide spectrum of activities, such as anti-inflammatory, anti-oxidant, anti-tumor, anti-diabetic, cardiovascular protective, neuroprotective, hepatoprotective effects. Moreover, various analytical methods were established for the quality evaluation and safety control of CM. This review synopsizes updated information concerning the origins, phytochemistry, pharmacology, analytical method and safety of CM, aiming to provide favorable references for modern CM research and application. In conclusion, continuing pharmacological investigations concerning CM should be conducted to unravel its pharmacological mechanisms. Further researches are necessary to obtain comprehensive and applicable analytical approach for quality evaluation and establish harmonized criteria of CM.
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Affiliation(s)
- Zhiqiang Wang
- School of Pharmacy, Anhui Medical University, Hefei 230032, China.
- Institute of Medicinal Plant Development, Chinese Academy of Medical Science, Peking Union Medical College, Beijing 100193, China.
- Key Laboratory of Bioactive Substances and Resources Utilization of Chinese Herbal Medicine, Ministry of Education, Beijing 100193, China.
| | - Chunnian He
- Institute of Medicinal Plant Development, Chinese Academy of Medical Science, Peking Union Medical College, Beijing 100193, China.
- Key Laboratory of Bioactive Substances and Resources Utilization of Chinese Herbal Medicine, Ministry of Education, Beijing 100193, China.
| | - Yong Peng
- Institute of Medicinal Plant Development, Chinese Academy of Medical Science, Peking Union Medical College, Beijing 100193, China.
- Key Laboratory of Bioactive Substances and Resources Utilization of Chinese Herbal Medicine, Ministry of Education, Beijing 100193, China.
| | - Feihu Chen
- School of Pharmacy, Anhui Medical University, Hefei 230032, China.
| | - Peigen Xiao
- Institute of Medicinal Plant Development, Chinese Academy of Medical Science, Peking Union Medical College, Beijing 100193, China.
- Key Laboratory of Bioactive Substances and Resources Utilization of Chinese Herbal Medicine, Ministry of Education, Beijing 100193, China.
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4
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Protein/ionic liquid/glassy carbon sensors following analyte focusing by ionic liquid micelle collapse for simultaneous determination of water soluble vitamins in plasma matrices. Talanta 2015; 139:150-8. [DOI: 10.1016/j.talanta.2015.02.025] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2014] [Revised: 02/10/2015] [Accepted: 02/14/2015] [Indexed: 12/26/2022]
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5
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Mirzaei M, Sawan M. Microelectronics-based biosensors dedicated to the detection of neurotransmitters: a review. SENSORS (BASEL, SWITZERLAND) 2014; 14:17981-8008. [PMID: 25264957 PMCID: PMC4239957 DOI: 10.3390/s141017981] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/11/2014] [Revised: 08/28/2014] [Accepted: 09/09/2014] [Indexed: 11/30/2022]
Abstract
Dysregulation of neurotransmitters (NTs) in the human body are related to diseases such as Parkinson's and Alzheimer's. The mechanisms of several neurological disorders, such as epilepsy, have been linked to NTs. Because the number of diagnosed cases is increasing, the diagnosis and treatment of such diseases are important. To detect biomolecules including NTs, microtechnology, micro and nanoelectronics have become popular in the form of the miniaturization of medical and clinical devices. They offer high-performance features in terms of sensitivity, as well as low-background noise. In this paper, we review various devices and circuit techniques used for monitoring NTs in vitro and in vivo and compare various methods described in recent publications.
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Affiliation(s)
- Maryam Mirzaei
- Polystim Neurotechnologies Laboratory, Electrical Engineering Department, Polytechnique Montreal, Montreal, QC H3T1J4, Canada.
| | - Mohamad Sawan
- Polystim Neurotechnologies Laboratory, Electrical Engineering Department, Polytechnique Montreal, Montreal, QC H3T1J4, Canada.
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6
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Determination of 5,7-dihydroxychromone and luteolin in peanut hulls by capillary electrophoresis with a multiwall carbon nanotube/poly(ethylene terephthalate) composite electrode. Food Chem 2014; 145:555-61. [DOI: 10.1016/j.foodchem.2013.08.118] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2012] [Revised: 09/16/2012] [Accepted: 08/28/2013] [Indexed: 11/23/2022]
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7
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Graphene–epoxy composite electrode fabricated by in situ polycondensation for enhanced amperometric detection in capillary electrophoresis. J Chromatogr A 2013; 1316:127-34. [DOI: 10.1016/j.chroma.2013.09.077] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2013] [Revised: 09/23/2013] [Accepted: 09/24/2013] [Indexed: 10/26/2022]
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8
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Huang T, Chen N, Zhang L, Chen G. Determination of Amifostine and WR1065 in Rat Plasma by CE with Amperometric Detection. Chromatographia 2013. [DOI: 10.1007/s10337-013-2535-2] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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9
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Sheng S, Liu S, Zhang L, Chen G. Graphene/poly(ethylene-co-vinyl acetate) composite electrode fabricated by melt compounding for capillary electrophoretic determination of flavones in Cacumen platycladi. J Sep Sci 2013; 36:721-8. [PMID: 23355382 DOI: 10.1002/jssc.201200856] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2012] [Revised: 10/24/2012] [Accepted: 10/25/2012] [Indexed: 11/07/2022]
Abstract
In this report, a graphene/poly(ethylene-co-vinyl acetate) composite electrode was fabricated by melt compounding for the amperometric detection of capillary electrophoresis. The composite electrode was fabricated by packing a mixture of graphene and melted poly(ethylene-co-vinyl acetate) in a piece of fused silica capillary under heat. The structure of the composite was investigated by scanning electron microscopy and Fourier transform infrared spectroscopy. The results indicated that graphene sheets were well dispersed in the composite to form an interconnected conducting network. The performance of this unique graphene-based detector has been demonstrated by separating and detecting rutin, quercitrin, kaempferol, and quercetin in Cacumen platycladi in combination with capillary electrophoresis. The four flavones have been well separated within 9 min in a 50-cm-long capillary at a separation voltage of 12 kV using a 50 mM sodium borate buffer (pH 9.2). The graphene-based detector offered significantly lower operating potentials, substantially enhanced signal-to-noise characteristics, lower expense of operation, high resistance to surface fouling, and enhanced stability. It showed long-term stability and repeatability with relative standard deviations of <5% for the peak current (n = 15).
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Affiliation(s)
- Shijun Sheng
- School of Pharmacy, Fudan University, Shanghai, P R China
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10
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Inoue J, Kaneta T, Imasaka T. Sheath-flow electrochemical detection of amino acids with a copper wire electrode in capillary electrophoresis. Electrophoresis 2012; 33:2743-7. [DOI: 10.1002/elps.201200059] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Junji Inoue
- Department of Applied Chemistry; Graduate School of Engineering; Kyushu University; Motooka; Fukuoka; Japan
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11
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Xu L, Guo Q, Yu H, Huang J, You T. Simultaneous determination of three β-blockers at a carbon nanofiber paste electrode by capillary electrophoresis coupled with amperometric detection. Talanta 2012; 97:462-7. [DOI: 10.1016/j.talanta.2012.04.063] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2011] [Revised: 04/28/2012] [Accepted: 04/30/2012] [Indexed: 02/09/2023]
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12
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Lu Y, Wang X, Chen D, Chen G. Polystyrene/graphene composite electrode fabricated by in situ polymerization for capillary electrophoretic determination of bioactive constituents in Herba Houttuyniae. Electrophoresis 2011; 32:1906-12. [PMID: 21769894 DOI: 10.1002/elps.201100162] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
A novel graphene/polystyrene composite electrode was developed for the enhanced amperometric detection of CE in this work. The composite electrode was fabricated on the basis of the in situ polymerization of a mixture of graphene and prepolymerized styrene in the bore of a piece of fused-silica capillary under heat. SEM, XRD, and FTIR offered insights into the nature of the composite. The results indicated that graphenes were well dispersed and embedded throughout the PS matrix to form an interconnected conducting network. The performance of this unique graphene-based detector has been demonstrated by separating and detecting rutin, isoquercitrin, quercitrin, and chlorogenic acid in Herba Houttuyniae (a traditional Chinese medicine) in combination with CE. The prepared graphene-based CE detector offered significantly lower detection potential, yielded enhanced signal-to-noise characteristics, and exhibited high resistance to surface fouling and enhanced stability. It showed long-term stability and reproducibility with a relative standard deviation of 3.1% for the peak current (n = 15).
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Affiliation(s)
- Yan Lu
- School of Pharmacy, Fudan University, Shanghai, P. R. China
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13
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Facile Preparation of Carbon Nanotube/Poly(ethyl 2-cyanoacrylate) Composite Electrode by Water-Vapor-Initiated Polymerization for Enhanced Amperometric Detection. Chemistry 2011; 17:12458-64. [DOI: 10.1002/chem.201101758] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2011] [Indexed: 11/07/2022]
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14
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Wang X, Li J, Qu W, Chen G. Fabrication of graphene/poly(methyl methacrylate) composite electrode for capillary electrophoretic determination of bioactive constituents in Herba Geranii. J Chromatogr A 2011; 1218:5542-8. [PMID: 21737079 DOI: 10.1016/j.chroma.2011.06.034] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2011] [Revised: 06/02/2011] [Accepted: 06/07/2011] [Indexed: 11/27/2022]
Abstract
This report describes the development and application of a novel graphene/poly(methyl methacrylate) composite electrode as a sensitive amperometric detector of capillary electrophoresis. The composite electrode was fabricated on the basis of the in situ polymerization of a mixture of graphene and prepolymerized methyl methacrylate in the microchannel of a piece of fused silica capillary under heat. SEM, XRD and FT-IR offered insights into the nature of the composite. The results indicated that graphenes were well dispersed in the composite to form an interconnected conducting network. The performance of this unique graphene-based detector has been demonstrated by separating and detecting seven naturally occurring phenolic compounds in Herba Geranii in combination with capillary electrophoresis. The graphene-based detector offered significantly lower operating potentials, substantially enhanced signal-to-noise characteristics, and lower expense of operation. The simplicity and significant performance exhibited by the graphene/poly(methyl methacrylate) composite electrode also indicate great promise for microchip CE, flowing injection analysis, and other microfluidic analysis systems.
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Affiliation(s)
- Xia Wang
- School of Pharmacy, Fudan University, 826 Zhangheng Road, Shanghai 200032, China
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15
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Chen B, Zhang L, Chen G. Determination of salidroside and tyrosol in Rhodiola by capillary electrophoresis with graphene/poly(urea-formaldehyde) composite modified electrode. Electrophoresis 2011; 32:870-6. [PMID: 21374630 DOI: 10.1002/elps.201000435] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2010] [Revised: 09/23/2010] [Accepted: 10/07/2010] [Indexed: 11/07/2022]
Abstract
This report describes the fabrication and application of a novel graphene/poly(urea-formaldehyde) composite modified electrode as a sensitive amperometric detector of CE. The composite electrode was fabricated on the basis of the in situ polycondensation of a mixture of graphenes and urea-formaldehyde prepolymers on the surface of a platinum disc electrode. It was coupled with CE for the separation and detection of salidroside and tyrosol in Rhodiola, a traditional Chinese medicine, to demonstrate its feasibility and performance. Salidroside and tyrosol have been well separated within 6 min in a 40 cm long capillary at a separation voltage of 12 kV using a 50 mM borate buffer (pH 9.8). The prepared graphene-based CE detector offered significantly lower detection potential, yielded enhanced signal-to-noise characteristics, and exhibited high resistance to surface fouling and enhanced stability. It showed long-term stability and reproducibility with relative standard deviations of less than 5% for the peak current (n = 15).
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Affiliation(s)
- Bo Chen
- School of Pharmacy, Fudan University, Shanghai, PR China
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16
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Opekar F, Štulík K. Some important combinations of detection techniques for electrophoresis in capillaries and on chips with emphasis on electrochemical principles. Electrophoresis 2011; 32:795-810. [DOI: 10.1002/elps.201000455] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2010] [Revised: 10/01/2010] [Accepted: 10/07/2010] [Indexed: 11/08/2022]
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17
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Application and potential of capillary electroseparation methods to determine antioxidant phenolic compounds from plant food material. J Pharm Biomed Anal 2010; 53:1130-60. [PMID: 20719447 DOI: 10.1016/j.jpba.2010.07.028] [Citation(s) in RCA: 73] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2010] [Revised: 07/09/2010] [Accepted: 07/18/2010] [Indexed: 12/17/2022]
Abstract
Antioxidants are one of the most common active ingredients of nutritionally functional foods which can play an important role in the prevention of oxidation and cellular damage inhibiting or delaying the oxidative processes. In recent years there has been an increased interest in the application of antioxidants to medical treatment as information is constantly gathered linking the development of human diseases to oxidative stress. Within antioxidants, phenolic molecules are an important category of compounds, commonly present in a wide variety of plant food materials. Their correct determination is pivotal nowadays and involves their extraction from the sample, analytical separation, identification, quantification and interpretation of the data. The aim of this review is to provide an overview about all the necessary steps of any analytical procedure to achieve the determination of phenolic compounds from plant matrices, paying particular attention to the application and potential of capillary electroseparation methods. Since it is quite complicated to establish a classification of plant food material, and to structure the current review, we will group the different matrices as follows: fruits, vegetables, herbs, spices and medicinal plants, beverages, vegetable oils, cereals, legumes and nuts and other matrices (including cocoa beans and bee products). At the end of the overview, we include two sections to explain the usefulness of the data about phenols provided by capillary electrophoresis and the newest trends.
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18
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Far infrared-assisted extraction followed by capillary electrophoresis for the determination of bioactive constituents in the leaves of Lycium barbarum Linn. J Chromatogr A 2010; 1217:4511-6. [DOI: 10.1016/j.chroma.2010.04.069] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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19
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Yang G, Zhang L, Chen G. Determination of Four Phenolic Compounds in Scirpus yagara Ohwi by CE with Amperometric Detection. Chromatographia 2009. [DOI: 10.1365/s10337-009-1389-0] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
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20
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Trojanowicz M. Recent developments in electrochemical flow detections—A review. Anal Chim Acta 2009; 653:36-58. [DOI: 10.1016/j.aca.2009.08.040] [Citation(s) in RCA: 103] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2009] [Revised: 08/04/2009] [Accepted: 08/28/2009] [Indexed: 12/17/2022]
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21
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Chen Z, Zhang L, Chen G. Carbon nanotube/poly(ethylene-co-vinyl acetate) composite electrode for capillary electrophoretic determination of esculin and esculetin in Cortex Fraxini. Electrophoresis 2009; 30:3419-26. [DOI: 10.1002/elps.200900019] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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22
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Wei B, Wang J, Chen Z, Chen G. Carbon-Nanotube-Alginate Composite Modified Electrode Fabricated by In Situ Gelation for Capillary Electrophoresis. Chemistry 2008; 14:9779-85. [DOI: 10.1002/chem.200801124] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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23
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Chen Z, Zhang J, Chen G. Simultaneous determination of flavones and phenolic acids in the leaves of Ricinus communis Linn. by capillary electrophoresis with amperometric detection. J Chromatogr B Analyt Technol Biomed Life Sci 2008; 863:101-6. [PMID: 18242153 DOI: 10.1016/j.jchromb.2008.01.002] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2007] [Revised: 12/28/2007] [Accepted: 01/04/2008] [Indexed: 11/18/2022]
Abstract
Capillary electrophoresis (CE) with amperometric detection (AD) has been developed for the separation and determination of disaccharide glycoside rutin, gentistic acid, quercetin, and gallic acid in the leaves of Ricinus communis Linn. for the first time. The effects of the acidity and the concentration of the running buffer, separation voltage, injection time, and detection potential were investigated to acquire the optimum conditions for the determination of the four analytes. The detection electrode was a 300microm diameter carbon disc electrode at a detection potential of +0.90V (versus saturated calomel electrode (SCE)). The four analytes could be well separated within 10min in a 40cm length fused silica capillary at a separation voltage of 15kV in a 50mM borate buffer (pH 9.0). The relation between peak current and analyte concentration was linear over about 3 orders of magnitude with detection limits (S/N=3) ranging from 0.8 to 2.9microM for all the analytes. The proposed method has been successfully applied to monitor flavones and phenolic acids in the real plant samples with satisfactory assay results.
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Affiliation(s)
- Zhi Chen
- School of Pharmacy, Fudan University, Shanghai 200032, China
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24
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Coufal P, Pacáková V, Stulík K. An evaluation of the experimental approaches to detection of small ions in CE. Electrophoresis 2007; 28:3379-89. [PMID: 17806126 DOI: 10.1002/elps.200700154] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
This review points out some important trends in the development of the detection techniques for small ions in CE. On the basis of selected literature references it briefly discusses some general requirements on detection techniques in CE. Various optical measurements, mass spectrometric approaches and electrochemical detection techniques are dealt with. Some specific features of microchip CE separation and detection are pointed out and possibilities of dual detection are mentioned. The principal parameters of the above detection techniques are then briefly compared.
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Affiliation(s)
- Pavel Coufal
- Department of Analytical Chemistry, Faculty of Science, Charles University in Prague, Albertov 2830, CZ-128 40 Prague 2, Czech Republic
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25
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Lu X, Huang WH, Ai F, Wang ZL, Cheng JK. Indirect determination of pyruvic acid by capillary electrophoresis with amperometric detection. J Chromatogr B Analyt Technol Biomed Life Sci 2007; 857:347-51. [PMID: 17723321 DOI: 10.1016/j.jchromb.2007.07.042] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2007] [Revised: 07/24/2007] [Accepted: 07/25/2007] [Indexed: 10/23/2022]
Abstract
A method of indirectly measuring pyruvic acid (PA) by capillary electrophoresis with amperometric detection is proposed for the first time. It is based on the oximation reaction between PA and hydroxylamine (NH(2)OH), and the quantification of PA was performed by direct and sensitive amperometric detection of excessive NH(2)OH after the oximation reaction. This method displayed a good sensitivity, and the detection limits of NH(2)OH and PA are 1.76 x 10(-7) and 3.88 x 10(-7)mol/L, respectively at S/N=3. The linear relationship between the peak current and PA concentration is exhibited over the range from 4 x 10(-6) to 1 x 10(-4)mol/L. This method has been applied to determine PA in rat plasma with satisfactory results.
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Affiliation(s)
- Xin Lu
- Department of Chemistry, Wuhan University, Wuhan, China
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26
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Advances in amperometric and conductometric detection in capillary and chip-based electrophoresis. Mikrochim Acta 2007. [DOI: 10.1007/s00604-007-0802-3] [Citation(s) in RCA: 64] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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27
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Boudko DY. Bioanalytical profile of the L-arginine/nitric oxide pathway and its evaluation by capillary electrophoresis. J Chromatogr B Analyt Technol Biomed Life Sci 2007; 851:186-210. [PMID: 17329176 PMCID: PMC2040328 DOI: 10.1016/j.jchromb.2007.02.011] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2006] [Revised: 01/30/2007] [Accepted: 02/06/2007] [Indexed: 02/07/2023]
Abstract
This review briefly summarizes recent progress in fundamental understanding and analytical profiling of the L-arginine/nitric oxide (NO) pathway. It focuses on key analytical references of NO actions and the experimental acquisition of these references in vivo, with capillary electrophoresis (CE) and high-performance capillary electrophoresis (HPCE) comprising one of the most flexible and technologically promising analytical platform for comprehensive high-resolution profiling of NO-related metabolites. Another aim of this review is to express demands and bridge efforts of experimental biologists, medical professionals and chemical analysis-oriented scientists who strive to understand evolution and physiological roles of NO and to develop analytical methods for use in biology and medicine.
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Affiliation(s)
- Dmitri Y Boudko
- The Whitney Laboratory for Marine Bioscience, 9505 Ocean Shore Blvd., St. Augustine, FL 32080, USA.
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28
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Sniehotta M, Schiffer E, Zürbig P, Novak J, Mischak H. CE – a multifunctional application for clinical diagnosis. Electrophoresis 2007; 28:1407-17. [PMID: 17427258 DOI: 10.1002/elps.200600581] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
CE has been used widely as an analytical tool with high separation power taking advantage of size, charge-to-size ratio, or isoelectric point of various analytes. In combination with detection methods, such as UV absorption, electrochemical detection, fluorescence, or mass spectrometry (MS), it allows the separation and detection of inorganic and organic ions, as well as complex compounds, such as polypeptides, nucleic acids, including PCR amplicons from viruses or bacteria. Recent interest in identification of biomarkers of diseases using body fluids leads to development of CE-MS techniques. These applications allowed identification of new potential biomarkers for clinical diagnosis and monitoring of therapeutic interventions. In this report, we present a technical overview of various CE techniques and discuss their applications in clinical medicine.
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Affiliation(s)
- Maike Sniehotta
- Mosaiques Diagnostics and Therapeutics AG, Hannover, Germany
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29
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Yao X, . JZ, . GC. Determination of Phenolic Acetophenones in Radix Cynanchi Paniculati by Capillary Electrophoresis with Electrochemical Detection. ACTA ACUST UNITED AC 2007. [DOI: 10.3923/jps.2007.273.282] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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30
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Mora MF, García CD. Electrophoretic separation of environmentally important phenolic compounds using montomorillonite-coated fused-silica capillaries. Electrophoresis 2007; 28:1197-203. [PMID: 17366482 DOI: 10.1002/elps.200600493] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
This paper reports a simple procedure for coating fused-silica capillaries with poly(diallyldimethyl ammonium chloride) and montmorillonite. The coated capillaries were characterized by performing EOF measurements as a function of buffer pH, number of layers of coating, and number of runs (stability). The coated capillaries showed a highly stable mu(EOF) (run-to-run RSD less than 1.5%, n = 20), allowing continuous use for several days without conditioning. The coated capillaries were then used for the effective separation of nine environmentally important phenolic compounds showing a significant improvement in the resolution, when compared to bare fused-silica capillaries. The EOF of the coated capillaries was constant in alkaline solutions (pH > or = 7), allowing the optimization of the separation conditions of phenolic compounds without significantly affecting the mu(EOF).
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Affiliation(s)
- Maria F Mora
- Department of Chemistry, The University of Texas at San Antonio, San Antonio, TX, USA
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31
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Yao X, Chen G. Simultaneous determination of p-hydroxyacetophenone, chlorogenic acid, and caffeic acid in Herba Artemisiae Scopariae by capillary electrophoresis with electrochemical detection. Anal Bioanal Chem 2007; 388:475-81. [PMID: 17333139 DOI: 10.1007/s00216-007-1198-y] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2007] [Accepted: 02/08/2007] [Indexed: 10/23/2022]
Abstract
Capillary electrophoresis with electrochemical detection has been employed for the determination of p-hydroxyacetophenone, chlorogenic acid, and caffeic acid in Herba Artemisiae Scopariae (the dried sprout of Artemisia scoparia Waldst. et Kit.). The effects of several important factors, such as the concentration and the acidity of the running buffer, separation voltage, injection time, and detection potential, were investigated to acquire the optimum conditions. The detection electrode was a 300-microm-diameter carbon disc electrode at a working potential of +0.90 V (relative to the saturated calomel electrode). The three analytes can be well separated within 11 min in a 40-cm-long fused-silica capillary at a separation voltage of 15 kV in 50 mM borate buffer (pH 9.2). The relation between peak current and analyte concentration was linear over about 3 orders of magnitude, with detection limits (signal-to-noise ratio of 3) of 0.31, 0.39, and 0.50 microM for p-hydroxyacetophenone, chlorogenic acid, and caffeic acid, respectively. The proposed method has been successfully applied to monitor the three bioactive constituents in real plant samples and to differentiate between different herbal drugs with satisfactory assay results.
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Affiliation(s)
- Xiao Yao
- School of Pharmacy, Fudan University, Shanghai, 200032, China.
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32
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Yao X, Gongyu G, Chen G. Determination of active constituents in Lonicera confusa DC. by capillary electrophoresis with amperometric detection. Biomed Chromatogr 2007; 20:1192-9. [PMID: 16799927 DOI: 10.1002/bmc.684] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
A method based on capillary electrophoresis with amperometric detection has been developed for the determination of luteolin, chlorogenic acid, 3,5-dicaffeoylquinic acid and caffeic acid in the dried flower buds, leaves and stems (three medicinal parts) of Lonicera confusa DC., respectively. The effects of several important factors such as detection potential, the concentration of the running buffer, separation voltage and injection time were investigated to acquire the optimum conditions. The detection electrode was a 300 microm diameter carbon disc electrode at a working potential of + 0.90 V (vs saturated calomel electrode). The four analytes can be well separated within 10 min in a 40 cm-long fused silica capillary at a separation voltage of 12 kV in a 50 mM borate-25 mM phosphate buffer (pH 8.0). The relationship between peak current and analyte concentration was linear over about 3 orders of magnitude with detection limits (S/N = 3) ranging from 0.35 to 0.52 microM for all analytes. The proposed method has been successfully applied to the monitoring of bioactive constituents in the real plant samples with satisfactory assay results.
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Affiliation(s)
- Xiao Yao
- Department of Chemistry, Fudan University, Shanghai 200433, People's Republic of China
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33
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Yao X, Wang Y, Chen G. Simultaneous determination of aminothiols, ascorbic acid and uric acid in biological samples by capillary electrophoresis with electrochemical detection. Biomed Chromatogr 2007; 21:520-6. [PMID: 17294501 DOI: 10.1002/bmc.787] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
A method based on capillary electrophoresis with electrochemical detection has been employed for the separation and determination of homocysteine, cysteine, reduced glutathione, ascorbic acid and uric acid. Effects of several important factors such as the acidity and concentration of the running buffer, separation voltage, injection time and detection potential were investigated to acquire the optimum conditions. The detection electrode was a 500 microm diameter platinum disk electrode at a working potential of +1.05 V (vs saturated calomel electrode). The five analytes were well separated within 10 min in a 50 cm long fused silica capillary at a separation voltage of 18 kV in a 100 mm phosphate buffer (pH 7.8). The relation between peak current and analyte concentration was linear over about 3 orders of magnitude with the detection limits (S/N = 3) ranging from 0.83 to 2.58 microm. The proposed method was successfully applied to determine cysteine, reduced glutathione, ascorbic acid and uric acid in human whole blood and rat brain tissues with satisfactory assay results and should find a wide range of bioanalytical applications.
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Affiliation(s)
- Xiao Yao
- Department of Chemistry, Fudan University, Shanghai 200433, People's Republic of China
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34
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Yao X, Xu X, Yang P, Chen G. Carbon nanotube/poly(methyl methacrylate) composite electrode for capillary electrophoretic measurement of honokiol and magnolol in Cortex Magnoliae Officinalis. Electrophoresis 2006; 27:3233-42. [PMID: 16850507 DOI: 10.1002/elps.200600048] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
This paper describes the development and the application of a novel carbon nanotube/poly(methyl methacrylate) (CNT/PMMA) composite electrode as a sensitive amperometric detector of CE. The composite electrode was fabricated on the basis of the in situ polymerization of a mixture of CNT and prepolymerized methylmethacrylate in the microchannel of a piece of fused-silica capillary under heat. The performance of this unique system has been demonstrated by separating and detecting honokiol and magnolol in traditional Chinese medicine, Cortex Magnoliae Officinalis. Factors influencing their separation and detection processes were examined and optimized. Honokiol and magnolol were well separated within 7 min in a 40 cm long capillary at a separation voltage of 15 kV using a 50 mM borate buffer (pH 9.2). The new CNT-based CE detector offered significantly lower operating potentials, yielded substantially enhanced S/N characteristics, and exhibited resistance to surface fouling and hence enhanced stability. It demonstrated long-term stability and reproducibility with RSDs of less than 5% for the peak current (n = 9) and should also find a wide range of applications in microchip CE, flowing injection analysis, and other microfluidic analysis systems.
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Affiliation(s)
- Xiao Yao
- Department of Chemistry, Fudan University, Shanghai, China
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35
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Ding Y, Garcia CD. Application of microchip-CE electrophoresis to follow the degradation of phenolic acids by aquatic plants. Electrophoresis 2006; 27:5119-27. [PMID: 17161003 DOI: 10.1002/elps.200600081] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
In this paper, we describe the separation and detection of six phenolic acids using an electrophoretic microchip with pulsed amperometric detection (PAD). The selected phenolic acids are particularly important because of their biological activity. The analysis of these compounds is typically performed by chromatography or standard CE coupled with a wide variety of detection modes. However, these methods are slow, labor intensive, involve a multistep solvent extraction, require skilled personnel, or use bulky and expensive instrumentation. In contrast, microchip CE offers the possibility of performing simpler, less expensive, and faster analysis. In addition, integrated devices can be custom-fabricated and incorporated with portable computers to perform on-site analysis. In the present report, the effect of the separation potential, buffer pH and composition, injection time and PAD parameters were studied in an effort to optimize both the separation and detection of these phenolic acids. Using the optimized conditions, the analysis can be performed in less than 3 min, with detection limits ranging from 0.73 microM (0.10 microg/mL) for 4-hydroxyphenylacetic acid to 2.12 microM (0.29 microg/mL) for salicylic acid. In order to demonstrate the capabilities of the device, the degradation of a mixture of these acids by two aquatic plants was followed using the optimized conditions.
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Affiliation(s)
- Yongsheng Ding
- Department of Chemistry, The University of Texas at San Antonio, San Antonio, TX 78249, USA
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36
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Chen G, Xu X, Zhu Y, Zhang L, Yang P. Determination of honokiol and magnolol in Cortex Magnoliae Officinalis by capillary electrophoresis with electrochemical detection. J Pharm Biomed Anal 2006; 41:1479-84. [PMID: 16704915 DOI: 10.1016/j.jpba.2006.04.001] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2006] [Revised: 03/22/2006] [Accepted: 04/06/2006] [Indexed: 11/30/2022]
Abstract
Capillary electrophoresis with electrochemical detection has been employed for the determination of honokiol and magnolol in Cortex Magnoliae Officinalis (i.e. Magnolia Bark) for the first time. Effects of several important factors such as the concentration and the acidity of the running buffer, separation voltage, injection time, and detection potential were investigated to acquire the optimum conditions. The detection electrode was a 300 microm diameter carbon disc electrode at a working potential of +0.90 V (versus saturated calomel electrode (SCE)). The two analytes can be well separated within 6 min in a 40 cm length fused silica capillary at a separation voltage of 18 kV in a 50mM borate buffer (pH 9.2). The relation between peak current and analyte concentration was linear over about three orders of magnitude with the detection limits (S/N=3) of 0.38 and 0.51 microM for honokiol and magnolol, respectively. The proposed method has been successfully applied to monitor the two bioactive constituents in the real plant samples with satisfactory assay results.
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Affiliation(s)
- Gang Chen
- Department of Chemistry, Fudan University, Shanghai 200433, China.
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37
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da Silva DLP, Rüttinger HH, Mrestani Y, Baum WF, Neubert RHH. Development of capillary electrophoresis methods for quantitative determination of taurine in vehicle system and biological media. Electrophoresis 2006; 27:2330-7. [PMID: 16856126 DOI: 10.1002/elps.200600097] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
CE methods have been developed for the determination of taurine in pharmaceutical formulation (microemulsion) and in biological media such as sweat. The CE system with end-column pulsed amperometric detection has been found to be an interesting method in comparison with UV and fluorescence detection for its simplicity and rapidity. A gold-disk electrode of 100 mm diameter was used as the working electrode. The effects of a field decoupler at the end of the capillary, separation voltage, injection and pressure times were investigated. A detection limit of 4 x 10(-5) mol/L was reached using integrated pulsed amperometric detection, a method successfully applied to taurine analysis of the biological samples such as sweat. For taurine analysis of oil-in-water microemulsion, fluorescence detector was the favored method, the detection limit of which was 4 x 10(-11) mol/L.
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Affiliation(s)
- Dayse L P da Silva
- Institute of Pharmaceutical Technology and Biopharmacy, Martin Luther University, Halle-Wittenberg, Germany
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38
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Vanderhoeven J, Pappaert K, Dutta B, Van Hummelen P, Desmet G. Development of capillary electrophoresis methods for quantitative determination of taurine in vehicle system and biological media. Electrophoresis 2006; 26:3773-9. [PMID: 16196108 DOI: 10.1002/elps.200500097] [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: 11/10/2022]
Abstract
In the present study, we demonstrate the benefits of a shear-driven rotating microchamber system for the enhancement of microarray hybridizations, by comparing the system with two commonly used hybridization techniques: purely diffusion-driven hybridization under coverslip and hybridization using a fully automated hybridization station, in which the sample is pumped in an oscillating manner. Starting from the same amount of DNA for the three different methods, a series of hybridization experiments using mouse lung and testis DNA is presented to demonstrate these benefits. The gain observed using the rotating microchamber is large: both in terms of analysis speed (up to tenfold increase) and in final spot intensity (up to sixfold increase). The gain is due to the combined effect of the hybridization chamber miniaturization (leading to a sample concentration increase if comparing iso-mass conditions) and the transport enhancement originating from the rotational shear-driven flow induced by the rotation of the chamber bottom wall.
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Affiliation(s)
- Johan Vanderhoeven
- Department of Chemical Engineering, Vrije Universiteit Brussel, Brussels, Belgium.
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39
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Psurek A, Matysik FM, Scriba GKE. Determination of enkephalin peptides by nonaqueous capillary electrophoresis with electrochemical detection. Electrophoresis 2006; 27:1199-208. [PMID: 16523458 DOI: 10.1002/elps.200500499] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
Nonaqueous capillary electrophoresis with electrochemical detection (NACE-ED) was applied to the analysis of enkephalin peptides. The effect of different buffer compositions on the electrophoretic behavior of methionine enkephalin, leucine enkephalin, and [D-Ala2]-leucine enkephalin was studied. Separation of the protonated and the deprotonated peptides was obtained using ACN/methanol-based electrolyte systems. The electrochemical behavior of the enkephalins was studied by the capillary batch injection analysis technique. NACE-ED yielded well-defined signals in the oxidation mode only for the negatively charged analytes. The optimized BGE for the counterelectroosmotic separation consisted of 10 mM ammonium acetate in ACN/methanol (3:1 v/v). Using a platinum microdisk electrode set to an actual potential of +0.65 V detection limits in the submicromolar range were observed which are about one order of magnitude lower compared to UV detection. Problems concerning EOF instability and electrode fouling caused by water and other neutral sample impurities transported by the EOF can be avoided in the EOF-inverted mode using poly(ethylene glycol)-coated capillaries and an actual working electrode potential of +1.0 V. For the quantification of the enkephalins [D-Ala2]leucine enkephalin was used as internal standard. The practical utility for the determination of enkephalins in spiked plasma samples after SPE was demonstrated.
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Affiliation(s)
- Arndt Psurek
- Department of Pharmaceutical Chemistry, School of Pharmacy, University of Jena, Jena, Germany
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40
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Xie T, Liu Q, Shi Y, Liu Q. Simultaneous determination of positional isomers of benzenediols by capillary zone electrophoresis with square wave amperometric detection. J Chromatogr A 2006; 1109:317-21. [PMID: 16494888 DOI: 10.1016/j.chroma.2006.01.135] [Citation(s) in RCA: 95] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2005] [Revised: 01/28/2006] [Accepted: 01/31/2006] [Indexed: 11/26/2022]
Abstract
A capillary zone electrophoresis method coupling square wave amperometric detection (SWAD) for the simultaneous determination of positional isomers of benzendiols (i.e. o-, m-, p-benzenediols) has been developed. Effects of several factors, such as the composition of the running buffer, the pH value, separation voltage, injection time and the potential applied to the working electrode, were investigated to acquire the optimum conditions. The efficacy of the boric acid and ascorbic acid in the running buffer were discussed. o-, m-, p-Benzendiols can be well separated within 8 min in a 50 cm length of 50 microm diameter fused-silica capillary at a separation voltage of +15 kV. Operated in a wall-jet configuration, a 100 microm Pt-disk electrode used as the working electrode exhibits good response for the analytes. The relation between peak current and analyte concentration was linear over two orders of magnitude with detection limits (S/N = 3) ranging from 0.5 to 1.5 microM for all analytes. The proposed method has been successfully applied to monitor the o-, m-, p-benzendiols contents in the environmental wastewater samples with satisfactory assay results.
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Affiliation(s)
- Tianyao Xie
- School of Chemistry and Chemical Engineering, Sun Yat-sen University, Guangzhou 510275, China.
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41
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Ding Y, Garcia CD. Pulsed amperometric detection with poly(dimethylsiloxane)-fabricated capillary electrophoresis microchips for the determination of EPA priority pollutants. Analyst 2006; 131:208-14. [PMID: 16440084 DOI: 10.1039/b509405d] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A miniaturized analytical system for separation and detection of three EPA priority phenolic pollutants, based on a poly(dimethylsiloxane)-fabricated capillary electrophoresis microchip and pulsed amperometric detection is described. The approach offers a rapid (less than 2 min), simultaneous measurement of three phenolic pollutants: phenol, 4,6-dinitro-o-cresol and pentachlorophenol. The highly stable response (RSD = 6.1%) observed for repetitive injections (n > 100) reflects the effectiveness of Au working electrode cleaned by pulsed amperometric detection. The effect of solution conditions, separation potential and detection waveform were optimized for both the separation and detection of phenols. Under the optimum conditions (5.0 mM phosphate buffer pH = 12.4, detection potential: 0.7 V, separation potential: 1200 V, injection time: 10 s) the baseline separation of the three selected compounds was achieved. Limits of detection of 2.2 microM (2.8 fmol), 0.9 microM (1.1 fmol), and 1.3 microM (1.6 fmol) were achieved for phenol, 4,6-dinitro-o-cresol and pentachlorophenol, respectively. A local city water sample and two over-the-counter sore-throat medicines were analyzed in order to demonstrate the capabilities of the proposed technique to face real applications.
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Affiliation(s)
- Yongsheng Ding
- Department of Chemistry, The University of Texas at San Antonio, TX 78249, USA
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42
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Chen G, Zhang L, Zhu Y. Determination of glycosides and sugars in Moutan Cortex by capillary electrophoresis with electrochemical detection. J Pharm Biomed Anal 2005; 41:129-34. [PMID: 16343840 DOI: 10.1016/j.jpba.2005.11.001] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2005] [Revised: 11/02/2005] [Accepted: 11/03/2005] [Indexed: 10/25/2022]
Abstract
A method based on capillary electrophoresis with electrochemical detection has been developed for the separation and determination of paeoniflorin, sucrose, paeonoside, glucose, and fructose in Moutan Cortex for the first time. Effects of several important factors such as the concentration of NaOH, separation voltage, injection time, and detection potential were investigated to acquire the optimum conditions. The detection electrode was a 300 microm diameter copper disc electrode at a working potential of +0.60 V (versus saturated calomel electrode (SCE)). The five analytes can be well-separated within 12 min in a 40 cm length fused silica capillary at a separation voltage of 12 kV in a 75 mM NaOH aqueous solution. The relation between peak current and analyte concentration was linear over about 3 orders of magnitude with detection limits (S/N = 3) ranging from 0.9 to 1.3 microM for all analytes. The proposed method has been successfully applied to monitor glycoside and sugar contents in the real plant samples with satisfactory assay results.
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Affiliation(s)
- Gang Chen
- Department of Chemistry, Fudan University, 220 Handan Road, Shanghai 200433, China.
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43
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Tsai DM, Tai HW, Shih PR, Chang RL, Wu H, Conte E, Zen JM. Incorporation of Disposable Screen-Printed Electrodes for Use in Capillary Electrophoresis End-Column Amperometric Detection System. ELECTROANAL 2005. [DOI: 10.1002/elan.200503321] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
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44
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Tsai DM, Lin KW, Zen JM, Chen HY, Hong RH. A new fabrication process for a microchip electrophoresis device integrated with a three-electrode electrochemical detector. Electrophoresis 2005; 26:3007-12. [PMID: 16007698 DOI: 10.1002/elps.200500107] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
We report here a novel and simple process for the fabrication of a poly(methyl methacrylate) (PMMA)-based microchip electrophoresis device, integrated with a screen-printed three-electrode electrochemical detector that does not require a replicate mold. In this approach, a photoresist layer constitutes both an adhesion layer and side walls of 50 mum wide and 50 mum tall microfluidic channels on a screen-printed three-electrode PMMA substrate. Openings were drilled for buffer reservoirs on an additional piece of PMMA, then the final device was bonded in a PMMA/photoresist/PMMA sandwich configuration. This process is inexpensive, less time-consuming, and simpler compared with traditional fabrication methods. The combination of this PMMA-based microchip fabrication together with screen-printed electrode technology holds great promise for the mass production of a single-use micrototal analytical system. Successful determination of uric acid and L-ascorbic acid with the presented system validates its utility. In combination with a suitable electrochemical detector, this device holds much promise for the determination of other analytes in various biological samples for medical and clinical diagnosis.
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Affiliation(s)
- Dong-Mung Tsai
- Department of Chemistry, National Chung Hsing University, Taichung, Taiwan
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45
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Abstract
Sensitivity is a crucial point in the development applications for medicine or environmental samples in which the analytes are present in the nanomolar range. Besides further technical development of detection systems, the multiplex sample injection technique can be applied for enhancing the signal-to-noise ratio. Hadamard transform is easily applied to microchip electrophoresis due to the fact that sample injection is generally achieved through cross, double-tee, or tee injector structures. This paper reports the first demonstration of a modified Hadamard transform electrophoresis on a microchip by using an amperometric detector. Contrary to the previous Hadamard applications, the resolution (number of points per unit of time) of electropherograms obtained is independent of the number of injections.
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Affiliation(s)
- Renato Guchardi
- Department of Chemistry, University of Basel, Spitalstrasse 51, CH-4056 Basel, Switzerland
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46
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Muna G, Quaiserova-Mocko V, Swain G. The Analysis of Chlorinated Phenol Solutions by Capillary Electrophoresis Coupled with Direct and Indirect Amperometric Detection Using a Boron-Doped Diamond Microelectrode. ELECTROANAL 2005. [DOI: 10.1002/elan.200403230] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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47
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Peng Y, Yuan J, Ye J. Determination of Active Components in St. John's Wort (Hypericum Perforatum) by Capillary Electrophoresis with Electrochemical Detection. ELECTROANAL 2005. [DOI: 10.1002/elan.200403219] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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48
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Determination of mannitol and three sugars in Ligustrum lucidum Ait. by capillary electrophoresis with electrochemical detection. Anal Chim Acta 2005. [DOI: 10.1016/j.aca.2004.08.053] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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49
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Chu Q, Fu L, Guan Y, Ye J. Fast determination of sugars in Coke and Diet Coke by miniaturized capillary electrophoresis with amperometric detection. J Sep Sci 2005; 28:234-8. [PMID: 15776924 DOI: 10.1002/jssc.200400015] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
The fast separation capability of a novel miniaturized capillary electrophoresis with amperometric detection (CE-AD) system was demonstrated by determining sugar contents in Coke and diet Coke with an estimated separation efficiency of 60,000 TP/m. Factors influencing the separation and detection processes were examined and optimized. The end-capillary 300 microm Cu wire amperometric detector offers favorable signal-to-noise characteristics at a relatively low potential (+0.50 V vs. Ag/AgCl) for detecting sugars. Three sugars (sucrose, glucose, and fructose) have been separated within 330 s in a 8.5 cm length capillary at a separation voltage of 1000 V using a 50 mM NaOH running buffer (pH 12.7). Highly linear response is obtained for the above compounds over the range of 5.0 to 2.0 x 10(2) microg/mL with low detection limit, down to 0.8 microg/mL for glucose (S/N = 3). The injection-to-injection repeatability for analytes in peak current (RSD < 3.6%) and for migration times (RSD < 1.4%) was excellent. The new miniaturized CE-AD system should find a wide range of analytical applications involving assays of carbohydrates as an alternative to conventional CE and micro-CE.
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Affiliation(s)
- Qingcui Chu
- Department of Chemistry, East China Normal University, Shanghai 200062, PR China
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50
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Chen G, Zhang L, Yang P. Determination of Three Bioactive Constituents in Moutan Cortex by Capillary Electrophoresis with Electrochemical Detection. ANAL SCI 2005; 21:1161-5. [PMID: 16270571 DOI: 10.2116/analsci.21.1161] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Capillary electrophoresis with electrochemical detection has been employed for the separation and determination of the three active constituents (paeonol, benzoyloxypaeoniflorin, and oxypaeoniflorin) in traditional Chinese medicine, Moutan Cortex (root cortex of Paeonia suffruticosa Andrews). The effects of several important factors, such as the concentration of running buffer, the separation voltage, the injection time, and the detection potential, were investigated to determine the optimum conditions. The detection electrode was a 300 microm diameter carbon-disc electrode at a working potential of +0.90 V (versus SCE). The three analytes could be well separated within 7 min in a 40 cm length fused-silica capillary at a separation voltage of 12 kV in a 50 mM borate buffer (pH 9.2). The relation between the peak current and the analyte concentration was linear over 3 orders of magnitude with detection limits (S/N = 3) ranging from 0.4 to 0.7 microM for all analytes. The proposed method has been successfully applied to the determination of paeonol, benzoyloxypaeoniflorin, and oxypaeoniflorin in real plant samples with satisfactory assay results.
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Affiliation(s)
- Gang Chen
- Department of Chemistry, Fudan University, Shanghai 200032, China.
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