1
|
KITAGAWA F, SOMA Y. Recent Applications of Dynamic On-Line Sample Preconcentration Techniques in Capillary Electrophoresis. CHROMATOGRAPHY 2022. [DOI: 10.15583/jpchrom.2022.012] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Affiliation(s)
- Fumihiko KITAGAWA
- Department of Frontier Materials Chemistry, Graduate School of Science and Technology, Hirosaki University
| | - Yuta SOMA
- Department of Frontier Materials Chemistry, Graduate School of Science and Technology, Hirosaki University
| |
Collapse
|
2
|
Obma A, Hemwech P, Phoolpho S, Bumrungpuech R, Wirasate S, Kaowphong S, Wilairat P, Chantiwas R. Silica nanolayer coated capillary by hydrothermal sol-gel process for amines separation and detection of tyramine in food products. Sci Rep 2022; 12:7460. [PMID: 35523909 PMCID: PMC9076594 DOI: 10.1038/s41598-022-11078-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2021] [Accepted: 04/18/2022] [Indexed: 11/30/2022] Open
Abstract
A hydrothermal sol–gel method for reproducible formation of silica nanolayer on the wall of silica capillaries was developed for electrochromatography. The formulation was optimized by observation of uniform gel formation on an optical microscope. The variables of the formulation include types of solvent, water-TEOS ratio, CTAB and urea contents, and mixing method. The procedure produced a coating of silica ca. 100 nm thick layer on the wall of the capillary. Surface morphology of the coating was characterized by SEM, contact angle and chemical composition by FT-IR spectroscopy and X-ray powder diffraction. The coating reduced the electroosmotic mobility producing enhanced separation performance. Eight standard amines (including tyramine and benzhydrylamine, as an internal standard) were separated with peak resolution Rs ≥ 2 for all adjacent peaks and plate number N ≥ 3.0 × 104 m-1. Calibration was linear from 5 to 200 µg L-1, with r2 > 0.9985 and instrumental LOD of 4.9 μg L-1. Five samples of food products were diluted and analyzed for the amines using the coated capillary and only tyramine was detected. Intra-day and inter-day precisions were less than 1.2%RSD. Percent recoveries of spiked tyramine in samples were 95 ± 3 to 106 ± 7% (n = 3).
Collapse
Affiliation(s)
- Apinya Obma
- Department of Chemistry, Faculty of Science, Mahidol University, Rama VI Rd., Bangkok, 10400, Thailand.,Center of Excellence for Innovation in Chemistry and Flow Innovation-Research for Science and Technology Laboratories (FIRST Labs), Faculty of Science, Mahidol University, Rama VI Rd., Bangkok, 10400, Thailand
| | - Pattamaporn Hemwech
- Department of Chemistry, Faculty of Science, Mahidol University, Rama VI Rd., Bangkok, 10400, Thailand.,Center of Excellence for Innovation in Chemistry and Flow Innovation-Research for Science and Technology Laboratories (FIRST Labs), Faculty of Science, Mahidol University, Rama VI Rd., Bangkok, 10400, Thailand
| | - Sittisak Phoolpho
- Department of Chemistry, Faculty of Science, Mahidol University, Rama VI Rd., Bangkok, 10400, Thailand.,Center of Excellence for Innovation in Chemistry and Flow Innovation-Research for Science and Technology Laboratories (FIRST Labs), Faculty of Science, Mahidol University, Rama VI Rd., Bangkok, 10400, Thailand
| | - Rawiwan Bumrungpuech
- Department of Chemistry, Faculty of Science, Mahidol University, Rama VI Rd., Bangkok, 10400, Thailand.,Center of Excellence for Innovation in Chemistry and Flow Innovation-Research for Science and Technology Laboratories (FIRST Labs), Faculty of Science, Mahidol University, Rama VI Rd., Bangkok, 10400, Thailand
| | - Supa Wirasate
- Department of Chemistry, Faculty of Science, Mahidol University, Rama VI Rd., Bangkok, 10400, Thailand.,Center for Surface Science and Engineering and Rubber Technology Research Center, Faculty of Science, Mahidol University, Salaya, Nakhon Pathom, 73170, Thailand
| | - Sulawan Kaowphong
- Department of Chemistry and Environmental Science Research Center (ESRC), Faculty of Science, Chiang Mai University, Chiang Mai, 50200, Thailand
| | - Prapin Wilairat
- Analytical Sciences and National Doping Test Institute, Mahidol University, Rama VI Rd., Bangkok, 10400, Thailand
| | - Rattikan Chantiwas
- Department of Chemistry, Faculty of Science, Mahidol University, Rama VI Rd., Bangkok, 10400, Thailand. .,Center of Excellence for Innovation in Chemistry and Flow Innovation-Research for Science and Technology Laboratories (FIRST Labs), Faculty of Science, Mahidol University, Rama VI Rd., Bangkok, 10400, Thailand.
| |
Collapse
|
3
|
Chu C, Liu C, Yang F, Lian L, Li J, Mao H, Yan J. A dual preconcentration method by combining micro matrix solid-phase dispersion extraction with field-enhanced sample injection and micelle to cyclodextrin stacking for sensitive analysis of neutral coumarins. Electrophoresis 2021; 42:1102-1107. [PMID: 33368428 DOI: 10.1002/elps.202000273] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2020] [Revised: 12/03/2020] [Accepted: 12/17/2020] [Indexed: 11/08/2022]
Abstract
A rapid, sensitive, environmental friendly dual preconcentration method by combining micro matrix solid-phase dispersion extraction with field-enhanced sample injection and micelle to cyclodextrin stacking has been developed for the determination of furocoumarins. Molecular sieve, KIT-6, was used as an adsorbent in micro matrix solid-phase dispersion process. The important parameters affecting off-line and online CE preconcentration efficiency were optimized. Under the optimal experimental conditions, all analytes showed good linearity (R2 > 0.999). The LODs of notopterol, isoimperatorin, and imperatorin were 0.1 μg/mL, 1.2 mg/kg, and 1.0 mg/kg, respectively. Compared with the normal CE method, the enrichment times were up to 300. Moreover, Angelicae Dahuricae Radix was used as the mode of complex solid sample matrix to demonstrate the prospect of application of this methodology. The results showed the proposed strategy is promising for determining trace furocoumarins in complex matrix samples, which might be applied as a powerful and economic tool in monitoring illegal cosmetic adding.
Collapse
Affiliation(s)
- Chu Chu
- College of Pharmaceutical Science, Zhejiang University of Technology, Hangzhou, P. R. China
| | - Caijing Liu
- College of Pharmaceutical Science, Zhejiang University of Technology, Hangzhou, P. R. China
| | - Fei Yang
- College of Pharmaceutical Science, Zhejiang University of Technology, Hangzhou, P. R. China
| | - Linmin Lian
- College of Pharmaceutical Science, Zhejiang University of Technology, Hangzhou, P. R. China
| | - Jing Li
- College of Pharmaceutical Science, Zhejiang University of Technology, Hangzhou, P. R. China
| | - Hui Mao
- College of Pharmaceutical Science, Zhejiang University of Technology, Hangzhou, P. R. China
| | - Jizhong Yan
- College of Pharmaceutical Science, Zhejiang University of Technology, Hangzhou, P. R. China
| |
Collapse
|
4
|
Tůma P. Determination of amino acids by capillary and microchip electrophoresis with contactless conductivity detection - Theory, instrumentation and applications. Talanta 2020; 224:121922. [PMID: 33379123 DOI: 10.1016/j.talanta.2020.121922] [Citation(s) in RCA: 34] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2020] [Revised: 11/22/2020] [Accepted: 11/23/2020] [Indexed: 01/15/2023]
Abstract
This review article summarises aspects of the determination of amino acids using capillary and chip electrophoresis in combination with contactless conductivity detection from their historical beginnings to the present time. Discussion is included of the theory of conductivity detection in electromigration techniques, the design of contactless conductivity cells for detection in capillaries and on microchips, including the use of computer programs for simulation of the conductivity response and the process of the electrophoretic separation of amino acids. Emphasis is placed on optimisation of the background electrolyte composition, chiral separation, multidimensional separation, stacking techniques and the use of multidetection systems. There is also a description of clinical applications, the determination of amino acids in foodstuffs, waters, soils and composts with emphasis on modern techniques of sample treatment, such as microdialysis, liquid membrane extraction and many other techniques.
Collapse
Affiliation(s)
- Petr Tůma
- Department of Hygiene, Third Faculty of Medicine, Charles University, Ruská 87, 100 00, Prague 10, Czech Republic.
| |
Collapse
|
5
|
Miyagawa S, Kimura M, Kagami S, Kawasaki T, Tokunaga Y. Utilization of a Crown Ether/Amine-Type Rotaxane as a Probe for the Versatile Detection of Anions and Acids by Thin-Layer Chromatography. Chem Asian J 2020; 15:3044-3049. [PMID: 32783335 DOI: 10.1002/asia.202000746] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2020] [Revised: 07/31/2020] [Indexed: 11/05/2022]
Abstract
A crown ether/amine-type [2]rotaxane was synthesized and utilized as a probe for the detection of acids and anions. The addition of acids to the amine-type [2]rotaxane solution generated corresponding crown ether/ammonium-type [2]rotaxanes, which were purified by silica gel column chromatography as ammonium salts. The isolated yields of the [2]rotaxanes, possessing a variety of anions, depended on the acidity and polarity of the counter anions. The behaviours of the ammonium-type [2]rotaxanes on thin-layer chromatography (TLC) silica gel reflected the properties of the counter anions. The treatment of the amine-type [2]rotaxane with acids afforded the corresponding ammonium-type [2]rotaxanes bearing several different anions. The ammonium-type [2]rotaxanes behaved similarly to the purified [2]rotaxanes on the TLC silica gel. Furthermore, we succeeded in the analysis of anions using mixtures of the amine-type [2]rotaxane and salts in an appropriate solvent. We demonstrated the detection of anions by the combination of TLC and the utilization of the [2]rotaxane probe.
Collapse
Affiliation(s)
- Shinobu Miyagawa
- Department of Materials Science and Engineering, Faculty of Engineering, University of Fukui, Bunkyo, Fukui, 910-8507, Japan
| | - Masaki Kimura
- Department of Materials Science and Engineering, Faculty of Engineering, University of Fukui, Bunkyo, Fukui, 910-8507, Japan
| | - Shin Kagami
- Department of Materials Science and Engineering, Faculty of Engineering, University of Fukui, Bunkyo, Fukui, 910-8507, Japan
| | - Tsuneomi Kawasaki
- Department of Applied Chemistry, Tokyo University of Science, Kagurazaka, Shinjuku-ku, Tokyo, 162-8601, Japan
| | - Yuji Tokunaga
- Department of Materials Science and Engineering, Faculty of Engineering, University of Fukui, Bunkyo, Fukui, 910-8507, Japan.,Research and Education Center for Regional Environment, University of Fukui, Bunkyo, Fukui, 910-8507, Japan
| |
Collapse
|
6
|
Haraga T, Tsujimura H, Miyauchi S, Kamimura T, Shibukawa M, Saito S. Purification of anionic fluorescent probes through precise fraction collection with a two-point detection system using multiple-stacking preparative capillary transient isotachophoresis. Electrophoresis 2020; 41:1152-1159. [PMID: 32253765 DOI: 10.1002/elps.201900399] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2019] [Revised: 03/27/2020] [Accepted: 03/29/2020] [Indexed: 11/11/2022]
Abstract
A novel combination of CE-based separation techniques was used for the precise fractionation of ionic compounds from impurities. The combination of on-capillary concentration and separation using transient isotachophoresis, with multiple injections and a two-point detection system provided higher efficiency, and accuracy at a microliter-scale injection volume, than when CE was individually used for purification. In this paper, we present successful applications of the CE fractionation techniques for the purification of fluorescein, fluorescein-4-isothiocyanate, two fluorescent metal ion probes, and a fluorescein-modified DNA aptamer. The purity of the isolated fluorescent probes ranged from 95 to 99%. Such high purity could not be achieved using chromatographic purification techniques. With relatively low dilution factors of 6-9, the purified probe solutions were practical for use as purified stock solutions. In addition, the fluorescein-modified DNA aptamer purified by our method was successfully used in a thrombin binding assay. The method developed was useful for the purification of anionic fluorescent reagents to be of ultratrace analytical grade for use with CE-LIF.
Collapse
Affiliation(s)
- Tomoko Haraga
- Department of Decommissioning and Waste Management, Japan Atomic Energy Agency, 2-4 Shirakata, Tokai-mura, Naka-gun, Ibaraki, 319-1195, Japan
| | - Hiroto Tsujimura
- Graduate School of Science and Engineering, Saitama University, 255 Shimo-Okubo, Sakura-ku, Saitama City, Saitama, 338-8570, Japan
| | - Saori Miyauchi
- Graduate School of Science and Engineering, Saitama University, 255 Shimo-Okubo, Sakura-ku, Saitama City, Saitama, 338-8570, Japan
| | - Takuya Kamimura
- Graduate School of Science and Engineering, Saitama University, 255 Shimo-Okubo, Sakura-ku, Saitama City, Saitama, 338-8570, Japan
| | - Masami Shibukawa
- Graduate School of Science and Engineering, Saitama University, 255 Shimo-Okubo, Sakura-ku, Saitama City, Saitama, 338-8570, Japan
| | - Shingo Saito
- Graduate School of Science and Engineering, Saitama University, 255 Shimo-Okubo, Sakura-ku, Saitama City, Saitama, 338-8570, Japan
| |
Collapse
|
7
|
Tan ML, Zhang M, Li F, Maya F, Breadmore MC. A three-dimensional printed electromembrane extraction device for capillary electrophoresis. J Chromatogr A 2019; 1595:215-220. [PMID: 30853162 DOI: 10.1016/j.chroma.2019.02.023] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2018] [Revised: 02/08/2019] [Accepted: 02/10/2019] [Indexed: 12/20/2022]
Abstract
A concentric electromembrane extraction preconcentration device was designed and fabricated using fused deposition modelling 3D printing. The device consisted of a hemispherical electrode sample vial printed from a filament of conductive polylactic acid (PLA), into which sat a smaller hemispherical 3D printed porous membrane acceptor vial. Application of voltage between a point-electrode placed in the center of 20 μL solution inside the acceptor vial and the electrode vial containing 1 mL of sample, enabled anion migration through the 3D printed porous material into the acceptor solution. Electromembrane extraction was proved using fluorescein for imaging of the extraction process, with preconcentration rates of 0.833 μM/sec at 120 V with close to 95% recovery. The performance of the fabricated porous 3D printed device was evaluated for the preconcentration of anions from water prior to capillary electrophoresis detection. Preconcentration factors ranging between 36-44 were obtained for chloride, nitrate, perchlorate and sulfate, while a lower performance was observed for weaker acids as fluoride and phosphate (3-4). The limit of detection (LOD) was determined to be 0.16 μM, 0.18 μM and 0.18 μM for NO3-, ClO4- and SO42- respectively. The extraction and quantitation of ions from a soil slurry without filtration, namely NO3- and SO42- content was determined to be 0.24 and 0.03 mmol/100 g of soil, respectively which are values in the range of those typically reported in soil samples.
Collapse
Affiliation(s)
- Ming Li Tan
- Australian Centre for Research on Separation Science (ACROSS), School of Natural Sciences - Chemistry, University of Tasmania, Private Bag 75, Hobart, TAS, 7001, Australia
| | - Min Zhang
- Guangxi Colleges and Universities Key Laboratory of Biomedical Sensing and Intelligent Instrument, School of Life and Environmental Sciences, Guilin University of Electronic Technology, Guilin, Guangxi, 541004, China
| | - Feng Li
- Australian Centre for Research on Separation Science (ACROSS), School of Natural Sciences - Chemistry, University of Tasmania, Private Bag 75, Hobart, TAS, 7001, Australia
| | - Fernando Maya
- Australian Centre for Research on Separation Science (ACROSS), School of Natural Sciences - Chemistry, University of Tasmania, Private Bag 75, Hobart, TAS, 7001, Australia
| | - Michael C Breadmore
- Australian Centre for Research on Separation Science (ACROSS), School of Natural Sciences - Chemistry, University of Tasmania, Private Bag 75, Hobart, TAS, 7001, Australia.
| |
Collapse
|
8
|
CHANG SY, LEE MY, WU CC. A Microchip Electrophoresis Device Integrated with the Top–bottom Antiparallel Electrodes of Indium Tin Oxide to Detect Inorganic Ions by Contact Conductivity. ANAL SCI 2018; 34:1231-1236. [DOI: 10.2116/analsci.18p115] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Affiliation(s)
- Sheng-Yao CHANG
- Department of Bio-industrial Mechatronics Engineering, National Chung Hsing University
| | - Ming-Yuan LEE
- Department of Bio-industrial Mechatronics Engineering, National Chung Hsing University
| | - Ching-Chou WU
- Department of Bio-industrial Mechatronics Engineering, National Chung Hsing University
- Innovation and Development Center of Sustainable Agriculture, National Chung Hsing University
| |
Collapse
|
9
|
Abstract
Microfluidics has been undergoing fast development in the past two decades due to its promising applications in biotechnology, medicine, and chemistry. Towards these applications, enhancing concentration sensitivity and detection resolution are indispensable to meet the detection limits because of the dilute sample concentrations, ultra-small sample volumes and short detection lengths in microfluidic devices. A variety of microfluidic techniques for concentrating analytes have been developed. This article presents an overview of analyte concentration techniques in microfluidics. We focus on discussing the physical mechanism of each concentration technique with its representative advancements and applications. Finally, the article is concluded by highlighting and discussing advantages and disadvantages of the reviewed techniques.
Collapse
Affiliation(s)
- Cunlu Zhao
- Key Laboratory of Thermo-Fluid Science and Engineering of MOE, School of Energy and Power Engineering, Xi’an Jiaotong University, Xi’an 710049, China
- Correspondence: (C.Z.); (C.Y.); Tel.: +86-29-8266-3222 (C.Z.); +65-6790-4883 (C.Y.)
| | - Zhengwei Ge
- School of Mechanical and Aerospace Engineering, Nanyang Technological University, 50 Nanyang Avenue, Singapore 639798, Singapore;
| | - Chun Yang
- School of Mechanical and Aerospace Engineering, Nanyang Technological University, 50 Nanyang Avenue, Singapore 639798, Singapore;
- Correspondence: (C.Z.); (C.Y.); Tel.: +86-29-8266-3222 (C.Z.); +65-6790-4883 (C.Y.)
| |
Collapse
|
10
|
El-Hady DA, Albishri HM, Wätzig H. Ionic liquids in enhancing the sensitivity of capillary electrophoresis: Off-line and on-line sample preconcentration techniques. Electrophoresis 2016; 37:1609-23. [DOI: 10.1002/elps.201600069] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2015] [Revised: 03/26/2016] [Accepted: 03/29/2016] [Indexed: 01/02/2023]
Affiliation(s)
- Deia Abd El-Hady
- Department of Chemistry, Faculty of Science; University of Jeddah; Jeddah Saudi Arabia
- Department of Chemistry, Faculty of Science; Assiut University; Assiut Egypt
| | - Hassan M. Albishri
- Department of Chemistry, Faculty of Science; King Abdulaziz University; Jeddah Saudi Arabia
| | - Hermann Wätzig
- Institute of Medicinal and Pharmaceutical Chemistry; TU Braunschweig; Braunschweig Germany
| |
Collapse
|
11
|
Tabani H, Khodaei K, Bide Y, Zare FD, Mirzaei S, Fakhari AR. Application of pH-sensitive magnetic nanoparticles microgel as a sorbent for the preconcentration of phenoxy acid herbicides in water samples. J Chromatogr A 2015; 1407:21-9. [PMID: 26159254 DOI: 10.1016/j.chroma.2015.06.057] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2015] [Revised: 06/19/2015] [Accepted: 06/22/2015] [Indexed: 11/26/2022]
Abstract
Introducing new sorbents is an interesting and debatable issue in the field of sample preparation. In this study, for the first time, a pH-sensitive magnetic nanoparticles microgel, Fe3O4-SiO2-oly(4-vinylpyridine), was introduced as a new sorbent. The operating mechanism of this sorbent is based on changing the pH value of the sample and consequently the structure of this pH-sensitive microgel is changed. So that, at pH 6.0 the microgel was ready to accept and load the analytes (partial swelling), and when the pH was increased to 8.0, the microgel was closed and analytes were trapped inside the sorbent (deswelling). At pH 2.0 the microgel was opened and the analytes were released from the microgel (swelling). As the adsorption and desorption mechanism is based on changing the pH and only aqueous medium is used as the effluent solvent, this method is introduced as a green extraction method. The use of this microgel resulted in excellent figures of merit. The limits of quantitation and detection for herbicides were obtained within the range of 10-30 and 3-10 ng mL(-1), respectively. Finally, the proposed method was successfully applied to determine the concentration of phenoxy acid herbicides as hazardous materials in water samples.
Collapse
Affiliation(s)
- Hadi Tabani
- Department of Environmental Geology, Research Institute of Applied Sciences (ACECR) Shahid Beheshti University, Tehran, Iran.
| | - Kamal Khodaei
- Department of Environmental Geology, Research Institute of Applied Sciences (ACECR) Shahid Beheshti University, Tehran, Iran
| | - Yasamin Bide
- Department of applied Chemistry, Faculty of Chemistry, Shahid Beheshti University, G. C., P.O. Box 19396-4716, Evin, Tehran, Iran
| | - Farzaneh Dorabadi Zare
- Department of applied Chemistry, Faculty of Chemistry, Shahid Beheshti University, G. C., P.O. Box 19396-4716, Evin, Tehran, Iran
| | - Saeed Mirzaei
- Department of Environmental Geology, Research Institute of Applied Sciences (ACECR) Shahid Beheshti University, Tehran, Iran
| | - Ali Reza Fakhari
- Department of applied Chemistry, Faculty of Chemistry, Shahid Beheshti University, G. C., P.O. Box 19396-4716, Evin, Tehran, Iran
| |
Collapse
|
12
|
Combination of graphene oxide-based solid phase extraction and electro membrane extraction for the preconcentration of chlorophenoxy acid herbicides in environmental samples. J Chromatogr A 2013; 1300:227-35. [DOI: 10.1016/j.chroma.2013.04.026] [Citation(s) in RCA: 97] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2013] [Revised: 04/10/2013] [Accepted: 04/11/2013] [Indexed: 11/21/2022]
|
13
|
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.
Collapse
Affiliation(s)
- M C Breadmore
- Australian Center for Research on Separation Science, School of Chemistry, University of Tasmania, Hobart, TAS, Australia.
| |
Collapse
|
14
|
Fakhari AR, Tabani H, Behdad H, Nojavan S, Taghizadeh M. Electrically-enhanced microextraction combined with maltodextrin-modified capillary electrophoresis for quantification of tolterodine enantiomers in biological samples. Microchem J 2013. [DOI: 10.1016/j.microc.2012.06.010] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
|
15
|
Single-drop microextraction as a powerful pretreatment tool for capillary electrophoresis: A review. Anal Chim Acta 2012; 739:14-24. [DOI: 10.1016/j.aca.2012.06.005] [Citation(s) in RCA: 56] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2012] [Revised: 06/02/2012] [Accepted: 06/02/2012] [Indexed: 01/16/2023]
|
16
|
Review of recent developments of on-line sample stacking techniques and their application in capillary electrophoresis. OPEN CHEM 2012. [DOI: 10.2478/s11532-012-0007-4] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023] Open
Abstract
AbstractCapillary electrophoresis (CE) has become one of the most useful tools in separation science because of its high separation efficiency, low cost, versatility, ease of sample preparation and automation. However, some limitations of CE, such as poor concentration sensitivity due to its lower sample loading and shorter optical path length, limits its further applications in separation science. In order to solve this problem, various on-line sample preconcentration techniques such as transient isotachophoresis preconcentration, field-enhanced sample stacking, micelle to solvent stacking, micelle collapse, dynamic pH junction, sweeping, solid phase extraction, single drop microextraction and liquid phase microextraction have been combined with CE. Recent developments, applications and some variants together with different combinations of these techniques integrating in CE are reviewed here and our discussions will be confined to the past three years (2008–2011).
Collapse
|
17
|
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]
|
18
|
Ye H, Xia S, Yu L, Xu X, Zheng C, Xu H, Wang L, Liu X, Cai Z, Chen G. Solid-phase extraction-field-amplified sample injection coupled with CE-ESI-MS for online pre-concentration and quantitative analysis of brain-gut peptides. Electrophoresis 2011; 32:2823-9. [DOI: 10.1002/elps.201000591] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
|
19
|
Dawod M, Chung DS. High-sensitivity capillary and microchip electrophoresis using electrokinetic supercharging. J Sep Sci 2011; 34:2790-9. [DOI: 10.1002/jssc.201100384] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2011] [Revised: 06/01/2011] [Accepted: 06/01/2011] [Indexed: 12/22/2022]
|
20
|
Heller M, Vitali L, Oliveira MAL, Costa ACO, Micke GA. A rapid sample screening method for authenticity control of whiskey using capillary electrophoresis with online preconcentration. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2011; 59:6882-6888. [PMID: 21662238 DOI: 10.1021/jf202218r] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
The present study aimed to develop a methodology using capillary electrophoresis for the determination of sinapaldehyde, syringaldehyde, coniferaldehyde, and vanillin in whiskey samples. The main objective was to obtain a screening method to differentiate authentic samples from seized samples suspected of being false using the phenolic aldehydes as chemical markers. The optimized background electrolyte was composed of 20 mmol L(-1) sodium tetraborate with 10% MeOH at pH 9.3. The study examined two kinds of sample stacking, using a long-end injection mode: normal sample stacking (NSM) and sample stacking with matrix removal (SWMR). In SWMR, the optimized injection time of the samples was 42 s (SWMR42); at this time, no matrix effects were observed. Values of r were >0.99 for the both methods. The LOD and LOQ were better than 100 and 330 mg mL(-1) for NSM and better than 22 and 73 mg L(-1) for SWMR. The CE-UV reliability in the aldehyde analysis in the real sample was compared statistically with LC-MS/MS methodology, and no significant differences were found, with a 95% confidence interval between the methodologies.
Collapse
Affiliation(s)
- Melina Heller
- Department of Chemistry, Federal University of Juiz de Fora, Juiz de Fora, MG, Brazil
| | | | | | | | | |
Collapse
|
21
|
Pack SP, Heo TH, Devarayapalli KC, Makino K. Quantitative analysis of specific target DNA oligomers using a DNA-immobilized packed-column system. Anal Bioanal Chem 2011; 401:667-76. [PMID: 21643855 DOI: 10.1007/s00216-011-5129-6] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2011] [Revised: 05/18/2011] [Accepted: 05/19/2011] [Indexed: 11/28/2022]
Abstract
Although a DNA-immobilized packed-column (DNA-packed column), which relies on sequence-dependent interactions of target DNA or mRNA (in the mobile phase) with DNA probes (on the silica particle) in a continuous flow process, could be considered as an alternative platform for quantitative analysis of specific DNA to DNA chip methodology, the performance in practice has not been satisfactory. In this study, we set up a more efficient quantitative analysis system based on a DNA-packed column by employing a temperature-gradient strategy and DMSO-containing mobile phase. Using a temperature-gradient strategy based on T(m) values of probe/target DNA hybridizations and DMSO (5%)-containing mobile phase, we succeeded in the quantitative analysis of a specific complementary target distinguishable from non-complementary DNA oligomers or other similar DNA samples. In addition, two different target DNA oligomers even with similar T(m) values were separated and detected quantitatively by using a packed column carrying two different DNA probes.
Collapse
Affiliation(s)
- Seung Pil Pack
- Department of Biotechnology and Bioinformatics, Korea University, Jochiwon, Chungnam, South Korea.
| | | | | | | |
Collapse
|
22
|
Meng L, Wang B, Luo F, Shen G, Wang Z, Guo M. Application of dispersive liquid–liquid microextraction and CE with UV detection for the chiral separation and determination of the multiple illicit drugs on forensic samples. Forensic Sci Int 2011; 209:42-7. [DOI: 10.1016/j.forsciint.2010.12.003] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2010] [Revised: 11/28/2010] [Accepted: 12/01/2010] [Indexed: 10/18/2022]
|
23
|
Kitagawa S, Noji A, Matsushita N, Nakagawa H, Asai T, Ohitani H. Large-volume sample on-line concentration of angiotensins in non-aqueous capillary electrophoresis. Electrophoresis 2011; 32:1480-5. [DOI: 10.1002/elps.201000673] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2010] [Revised: 02/28/2011] [Accepted: 03/10/2011] [Indexed: 11/05/2022]
|
24
|
Breadmore MC, Quirino JP, Thormann W. Insight into the mechanism of transient trapping in micellar electrokinetic chromatography. Electrophoresis 2011; 32:542-9. [DOI: 10.1002/elps.201000547] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
|
25
|
Saito S, Nakano Y, Hikichi A, Suzuki R, Yoshimoto K, Maeda M, Aoyama M, Shibukawa M. Ultrasensitive CE for heavy metal ions using the variations in the chemical structures formed from new octadentate fluorescent probes and cationic polymers. Analyst 2011; 136:2697-705. [DOI: 10.1039/c0an00777c] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
|
26
|
Breadmore MC, Dawod M, Quirino JP. Recent advances in enhancing the sensitivity of electrophoresis and electrochromatography in capillaries and microchips (2008-2010). Electrophoresis 2010; 32:127-48. [PMID: 21171119 DOI: 10.1002/elps.201000412] [Citation(s) in RCA: 129] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2010] [Revised: 09/15/2010] [Accepted: 09/16/2010] [Indexed: 01/22/2023]
Abstract
Capillary electrophoresis has been alive for over two decades now; yet, its sensitivity is still regarded as being inferior to that of more traditional methods of separation such as HPLC. As such, it is unsurprising that overcoming this issue still generates much scientific interest. This review continues to update this series of reviews, first published in Electrophoresis in 2007, with an update published in 2009 and covers material published through to June 2010. It includes developments in the fields of stacking, covering all methods from field-amplified sample stacking and large volume sample stacking, through to ITP, dynamic pH junction and sweeping. Attention is also given to on-line or in-line extraction methods that have been used for electrophoresis.
Collapse
Affiliation(s)
- Michael C Breadmore
- Australian Centre for Research on Separation Science, School of Chemistry, University of Tasmania, Hobart, TAS, Australia.
| | | | | |
Collapse
|
27
|
Highly sensitive transient isotachophoresis sample stacking coupling with capillary electrophoresis-amperometric detection for analysis of doping substances. Talanta 2010; 81:1288-94. [DOI: 10.1016/j.talanta.2010.02.023] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2009] [Revised: 01/31/2010] [Accepted: 02/07/2010] [Indexed: 11/20/2022]
|
28
|
Huhn C, Pyell U. Diffusion as major source of band broadening in field-amplified sample stacking under negligible electroosmotic flow velocity conditions. J Chromatogr A 2010; 1217:4476-86. [DOI: 10.1016/j.chroma.2010.04.008] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2009] [Revised: 03/31/2010] [Accepted: 04/08/2010] [Indexed: 11/30/2022]
|
29
|
Dawod M, Breadmore MC, Guijt RM, Haddad PR. Electrokinetic supercharging-electrospray ionisation-mass spectrometry for separation and on-line preconcentration of hypolipidaemic drugs in water samples. Electrophoresis 2010; 31:1184-1193. [DOI: 10.1002/elps.200900420] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
|
30
|
Persat A, Suss ME, Santiago JG. Basic principles of electrolyte chemistry for microfluidic electrokinetics. Part II: Coupling between ion mobility, electrolysis, and acid-base equilibria. LAB ON A CHIP 2009; 9:2454-2469. [PMID: 19680571 DOI: 10.1039/b906468k] [Citation(s) in RCA: 69] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
We present elements of electrolyte dynamics and electrochemistry relevant to microfluidic electrokinetics experiments. In Part I of this two-paper series, we presented a review and introduction to the fundamentals of acid-base chemistry. Here, we first summarize the coupling between acid-base equilibrium chemistry and electrophoretic mobilities of electrolytes, at both infinite and finite dilution. We then discuss the effects of electrode reactions on microfluidic electrokinetic experiments and derive a model for pH changes in microchip reservoirs during typical direct-current electrokinetic experiments. We present a model for the potential drop in typical microchip electrophoresis device. The latter includes finite element simulation to estimate the relative effects of channel and reservoir dimensions. Finally, we summarize effects of electrode and electrolyte characteristics on potential drop in microfluidic devices. As a whole, the discussions highlight the importance of the coupling between electromigration and electrophoresis, acid-base equilibria, and electrochemical reactions.
Collapse
Affiliation(s)
- Alexandre Persat
- Department of Mechanical Engineering, Stanford University, Stanford, CA 94305, USA
| | | | | |
Collapse
|
31
|
Choi K, Jin YG, Chung DS. In-line coupling of two-phase single drop microextraction and large volume stacking using an electroosmotic flow pump in nonaqueous capillary electrophoresis. J Chromatogr A 2009; 1216:6466-70. [DOI: 10.1016/j.chroma.2009.07.047] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2009] [Revised: 07/21/2009] [Accepted: 07/27/2009] [Indexed: 11/29/2022]
|
32
|
Johns C, Breadmore MC, Macka M, Ryvolová M, Haddad PR. Recent significant developments in detection and method development for the determination of inorganic ions by CE. Electrophoresis 2009; 30 Suppl 1:S53-67. [DOI: 10.1002/elps.200900103] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
|
33
|
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.
Collapse
|
34
|
Lagarrigue M, Bossée A, Bégos A, Delaunay N, Varenne A, Gareil P, Bellier B. Analysis of nerve agent degradation products in high-conductivity matrices by transient ITP preconcentration and CZE separation coupled to ESI-MS. Electrophoresis 2009; 30:1522-30. [DOI: 10.1002/elps.200800438] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
|
35
|
Dawod M, Breadmore MC, Guijt RM, Haddad PR. Counter-flow electrokinetic supercharging for the determination of non-steroidal anti-inflammatory drugs in water samples. J Chromatogr A 2009; 1216:3380-6. [DOI: 10.1016/j.chroma.2009.02.014] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2008] [Revised: 02/02/2009] [Accepted: 02/04/2009] [Indexed: 12/01/2022]
|
36
|
Almeda S, Arce L, Benavente F, Sanz-Nebot V, Barbosa J, Valcárcel M. Comparison of off- and in-line solid-phase extraction for enhancing sensitivity in capillary electrophoresis using ochratoxin as a model compound. Anal Bioanal Chem 2009; 394:609-15. [PMID: 19252901 DOI: 10.1007/s00216-009-2696-x] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2008] [Revised: 01/29/2009] [Accepted: 02/09/2009] [Indexed: 11/25/2022]
Abstract
This paper proposes and compares two approaches based on off- and in-line solid-phase extraction (SPE), intended to enhance sensitivity in capillary electrophoresis with ultraviolet detection (CE-UV) using as a model the determination of ochratoxin A (OA) in river water samples. In the off-line SPE mode, the reversed-phase sorbent (octadecilsylane, C(18)) selectively retains the target analyte (OA) and allows large volumes of the sample (70 mL) to be introduced and subsequently eluted in a small volume (0.1 mL) of an appropriate solution. In the in-line SPE mode, a custom-made microcartridge is inserted near the inlet of the capillary, which is filled with the same C(18) sorbent. This solid phase selectively retains OA present in a sample volume as low as approximately 640 microL for subsequent elution with ca. 135 nL of an appropriate eluent. The limit of detection (LOD) obtained with the in-line SPE method was 1 ng L(-1), which is 3 orders of magnitude lower than that obtained with CE-UV and roughly 1 order lower than that provided by the off-line SPE-CE-UV method.
Collapse
Affiliation(s)
- S Almeda
- Department of Analytical Chemistry, University of Córdoba, Campus de Rabanales, 14071, Córdoba, Spain
| | | | | | | | | | | |
Collapse
|
37
|
Cao J, Qi LW, Chen J, Li P. Pressure and electrokinetic injections for on-line sample stacking neutral analytes in microemulsion electrokinetic chromatography with salt-containing matrixes. Electrophoresis 2009; 29:4422-30. [PMID: 18942679 DOI: 10.1002/elps.200800190] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
An on-line technique for pressure and electrokinetic injections of long sample plugs with simultaneous stacking of neutral analytes (notoginsenoside R(1), ginsenoside Rg(1), ginsenoside Rf, ginsenoside Rh(1), ginsenoside Rd, ginsenoside Rg3) in microemulsion electrokinetic chromatography is presented. The effects of salt concentration, sample plug length, organic modification of the sample matrix, oil phase and SDS concentration on stacking efficiency were examined in order to optimize the two injection methods. In microemulsion electrokinetic chromatography, the effect of the type of oil and SDS content on stacking mechanism is often sophisticated. This study had demonstrated that the oil type and SDS content in microemulsion indeed markedly altered the affinity of microemulsion with analytes. Finally, in comparison with the electrokinetic injection method, the most apparent disadvantages of the pressure injection method were the relatively high LOD and poor reproducibility.
Collapse
Affiliation(s)
- Jun Cao
- Key Laboratory of Modern Chinese Medicines (China Pharmaceutical University), Ministry of Education, Nanjing, PR China
| | | | | | | |
Collapse
|
38
|
Breadmore MC, Thabano JRE, Dawod M, Kazarian AA, Quirino JP, Guijt RM. Recent advances in enhancing the sensitivity of electrophoresis and electrochromatography in capillaries and microchips (2006-2008). Electrophoresis 2009; 30:230-48. [DOI: 10.1002/elps.200800435] [Citation(s) in RCA: 118] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
|
39
|
Danger G, Pascal R, Cottet H. Non-uniform surface charge distributions in CE: Theoretical and experimental approach based on Taylor dispersion. Electrophoresis 2008; 29:4226-37. [DOI: 10.1002/elps.200800128] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
|
40
|
Danger G, Ross D. Development of a temperature gradient focusing method for in situ extraterrestrial biomarker analysis. Electrophoresis 2008; 29:3107-14. [DOI: 10.1002/elps.200700778] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
|
41
|
Affiliation(s)
- Tarun K. Khurana
- Department of Mechanical Engineering, Stanford University, 440 Escondido Mall, Building 530, Room 225, Stanford, California 94305
| | - Juan G. Santiago
- Department of Mechanical Engineering, Stanford University, 440 Escondido Mall, Building 530, Room 225, Stanford, California 94305
| |
Collapse
|
42
|
Breadmore MC, Quirino JP. 100 000-Fold Concentration of Anions in Capillary Zone Electrophoresis Using Electroosmotic Flow Controlled Counterflow Isotachophoretic Stacking under Field Amplified Conditions. Anal Chem 2008; 80:6373-81. [DOI: 10.1021/ac8007835] [Citation(s) in RCA: 78] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Michael C. Breadmore
- Australian Centre for Research on Separation Science, School of Chemistry, University of Tasmania, G.P.O. Box 252-75, Hobart, Tasmania 7001, Australia
| | - Joselito P. Quirino
- Australian Centre for Research on Separation Science, School of Chemistry, University of Tasmania, G.P.O. Box 252-75, Hobart, Tasmania 7001, Australia
| |
Collapse
|
43
|
Pritchett JS, Pulido JS, Shippy SA. Measurement of region-specific nitrate levels of the posterior chamber of the rat eye using low-flow push-pull perfusion. Anal Chem 2008; 80:5342-9. [PMID: 18549240 DOI: 10.1021/ac800238d] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
The determination of the presence of nitric oxide metabolites in the rat vitreous cavity in a regioselective manner is complicated by the size and shape of the eye as well as the diffusivity of the molecule and its metabolites. In this work, in vivo low-flow push-pull perfusion sampling was utilized with a rapid capillary electrophoretic assay to monitor levels of the major NO metabolite, nitrate, at the vitreoretinal interface (VRI) of normal and aged rat models. The sampling probe tips were placed in three different positions in the posterior chamber through a 29-gauge guide needle. Sampling was performed along the VRI over the optic nerve head and regions peripheral to the optic nerve head. Additionally, samples were collected from the middle vitreous region to compare to VRI sampling. A significant (P < 0.05) difference in the perfusate nitrate concentration was observed in each location, which may be due to the source of NO production or the clearance mechanism of the molecule from the vitreous cavity. Infusion of L-NAME with physiological saline led to a significant decrease (35%) in the observed nitrate level. LFPPP was then utilized to observe nitrate levels after an average of 4.5 months of aging. A 3-fold increase in the mean level of nitrate over the optic nerve head was observed in mature animals compared to younger control animals. Precise measurement of NO metabolites along the VRI may provide insights into the function of NO in maintaining homeostatic conditions and the molecular changes at the diseased retina.
Collapse
Affiliation(s)
- Jeanita S Pritchett
- Department of Chemistry, University of Illinois at Chicago, 845 West Taylor Street, Chicago, Illinois 60607, USA
| | | | | |
Collapse
|
44
|
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]
|
45
|
Alnajjar AA. Capillary electrophoresis with fluorescence detection for sensitive analysis of morphine and 6-acetylmorphine in human urine. ACTA CHROMATOGR 2008. [DOI: 10.1556/achrom.20.2008.2.7] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
|
46
|
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]
|
47
|
Matsui T, Franzke J, Manz A, Janasek D. Temperature gradient focusing in a PDMS/glass hybrid microfluidic chip. Electrophoresis 2008; 28:4606-11. [PMID: 18008305 DOI: 10.1002/elps.200700272] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
This paper reports the application of temperature gradient focusing (TGF) in a PDMS/glass hybrid microfluidic chip. With TGF, by the combination of a temperature gradient along a microchannel, an applied electric field, and a buffer with a temperature-dependent ionic strength, analytes are focused by balancing their electrophoretic velocities against the bulk velocity of the buffer containing the analytes. In this work, Oregon Green 488 carboxylic acid was concentrated approximately 30 times as high as the initial concentration in 45 s at moderate electric strength of 70 V/cm and a temperature gradient of 55 degrees C across the PDMS/glass hybrid microfluidic chip with a 1 cm long capillary.
Collapse
Affiliation(s)
- Takuya Matsui
- ISAS-Institute for Analytical Sciences Dortmund and Berlin, Dortmund, Germany
| | | | | | | |
Collapse
|
48
|
Simpson SL, Quirino JP, Terabe S. On-line sample preconcentration in capillary electrophoresis. J Chromatogr A 2008; 1184:504-41. [DOI: 10.1016/j.chroma.2007.11.001] [Citation(s) in RCA: 269] [Impact Index Per Article: 16.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2007] [Revised: 10/30/2007] [Accepted: 11/01/2007] [Indexed: 02/06/2023]
|
49
|
Macià A, Borrull F, Calull M, Benavente F, Hernández E, Sanz-Nebot V, Barbosa J, Aguilar C. Sensitivity enhancement for the analysis of naproxen in tap water by solid-phase extraction coupled in-line to capillary electrophoresis. J Sep Sci 2008; 31:872-80. [DOI: 10.1002/jssc.200700593] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
|
50
|
Sereda SV, Shpak AV, Pirogov AV, Shpigun OA. Electrostacking with ion flow superposition as a method of concentration in electrophoresis. RUSS J ELECTROCHEM+ 2007. [DOI: 10.1134/s1023193507120117] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
|