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Vergara-Barberán M, Mompó-Roselló Ó, Herrero-Martínez JM, Simó-Alfonso EF. Poly(ethylene glycol) diacrylate based monolithic capillary columns for the analysis of polar small solutes by capillary electrochromatography. J Sep Sci 2018; 41:2632-2639. [DOI: 10.1002/jssc.201800184] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2018] [Revised: 03/23/2018] [Accepted: 03/26/2018] [Indexed: 12/16/2022]
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2
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Liu X, Liu X, Liu X, Guo L, Yang L, Wang S. Graphene oxide and reduced graphene oxide as novel stationary phases via electrostatic assembly for open-tubular capillary electrochromatography. Electrophoresis 2014; 34:1869-76. [PMID: 23977681 DOI: 10.1002/elps.201300046] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
We present here the application of graphene oxide (GO) and reduced graphene oxide (GOOH) sheet as novel stationary phases for open-tubular CEC (OTCEC) separation based on electrostatic assembly. The inner walls of a bare capillary column was first modified by ionic assembly of poly (diallyldimethylammonium chloride) (PDDA), and then negatively charged GO or GOOH was easily assembled on a positively charged interior walls of the capillary by electrostatic force. Scanning Electron Microscope images showed that GO and GOOH can still maintain sheet-layer-like structure when coated onto the capillary via electrostatic assembly. The chromatographic properties of the GO and GOOH coated columns were evaluated via OTCEC separations of various kinds of analytes, including three acid nitrophenol isomers, three basic nitroaniline isomers, and four neutral PAHs. Efficient separations of all the analytes were achieved with optimized buffer pH and organic additive. The reproducibility and stability of the GO or GOOH coated columns were investigated. Our results indicate the capability of application GO or GOOH sheet in OTCEC separation, which can be coated on the inner wall of fused-silica capillary via electrostatic assembly.
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Affiliation(s)
- Xiaoling Liu
- Faculty of Chemistry, Northeast Normal University, Changchun, Jilin, P. R. China
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3
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Tian M, Zhang J, Mohamed AC, Han Y, Guo L, Yang L. Efficient capillary electrophoresis separation and determination of free amino acids in beer samples. Electrophoresis 2013; 35:577-84. [DOI: 10.1002/elps.201300416] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2013] [Revised: 10/15/2013] [Accepted: 10/28/2013] [Indexed: 02/06/2023]
Affiliation(s)
- Miaomiao Tian
- Faculty of Chemistry; Northeast Normal University; Changchun Jilin P. R. China
| | - Junfu Zhang
- Department of Public Security of Jilin Province; Institute of Forensic Science; Changchun Jilin P. R. China
| | | | - Yingzi Han
- Faculty of Chemistry; Northeast Normal University; Changchun Jilin P. R. China
| | - Liping Guo
- Faculty of Chemistry; Northeast Normal University; Changchun Jilin P. R. China
| | - Li Yang
- Faculty of Chemistry; Northeast Normal University; Changchun Jilin P. R. China
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4
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Lin H, Zhang Z, Dong J, Liu Z, Ou J, Zou H. Preparation of polyhedral oligomeric silsesquioxane based hybrid monoliths by ring-opening polymerization for capillary LC and CEC. J Sep Sci 2013; 36:2819-25. [DOI: 10.1002/jssc.201300417] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2013] [Revised: 05/28/2013] [Accepted: 05/28/2013] [Indexed: 11/07/2022]
Affiliation(s)
- Hui Lin
- CAS Key Laboratory of Separation Science for Analytical Chemistry; National Chromatographic R & A Center, Dalian Institute of Chemical Physics, Chinese Academy of Sciences (CAS); Dalian China
- University of Chinese Academy of Sciences; Beijing China
| | - Zhenbin Zhang
- CAS Key Laboratory of Separation Science for Analytical Chemistry; National Chromatographic R & A Center, Dalian Institute of Chemical Physics, Chinese Academy of Sciences (CAS); Dalian China
- University of Chinese Academy of Sciences; Beijing China
| | - Jing Dong
- CAS Key Laboratory of Separation Science for Analytical Chemistry; National Chromatographic R & A Center, Dalian Institute of Chemical Physics, Chinese Academy of Sciences (CAS); Dalian China
| | - Zhongshan Liu
- CAS Key Laboratory of Separation Science for Analytical Chemistry; National Chromatographic R & A Center, Dalian Institute of Chemical Physics, Chinese Academy of Sciences (CAS); Dalian China
- University of Chinese Academy of Sciences; Beijing China
| | - Junjie Ou
- CAS Key Laboratory of Separation Science for Analytical Chemistry; National Chromatographic R & A Center, Dalian Institute of Chemical Physics, Chinese Academy of Sciences (CAS); Dalian China
| | - Hanfa Zou
- CAS Key Laboratory of Separation Science for Analytical Chemistry; National Chromatographic R & A Center, Dalian Institute of Chemical Physics, Chinese Academy of Sciences (CAS); Dalian China
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5
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Aguiar VS, Bottoli CBG. Development and characterization of hydrophobic organic monolithic columns for use in capillary electrochromatography. Microchem J 2013. [DOI: 10.1016/j.microc.2012.04.006] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
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6
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Wang M, Feng R, Shen J, Chen H, Zeng Z. Capillary Electrochromatography with Liquid Crystal Crown Ether Modified Hybrid Silica Monolith for Analysis of Imidacloprid and Carbendazim in Tomatoes. B KOREAN CHEM SOC 2012. [DOI: 10.5012/bkcs.2012.33.7.2224] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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7
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Hessel V, Vural Gürsel I, Wang Q, Noël T, Lang J. Potential Analysis of Smart Flow Processing and Micro Process Technology for Fastening Process Development: Use of Chemistry and Process Design as Intensification Fields. Chem Eng Technol 2012. [DOI: 10.1002/ceat.201200038] [Citation(s) in RCA: 95] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
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8
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Hessel V, Gürsel I, Wang Q, Noël T, Lang J. Potenzialanalyse von Milli- und Mikroprozesstechniken für die Verkürzung von Prozessentwicklungszeiten - Chemie und Prozessdesign als Intensivierungsfelder. CHEM-ING-TECH 2012. [DOI: 10.1002/cite.201200007] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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9
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Pieters S, Tistaert C, Alaerts G, Bodzioch K, Mangelings D, Dejaegher B, Rivière C, Nguyen Hoai N, Chau Van M, Quetin-Leclerq J, Vander Heyden Y. Pressurized capillary electrochromatography in a screening for possible antioxidant molecules in Mallotus fingerprints: Challenges, potentials and prospects. Talanta 2011; 83:1188-97. [DOI: 10.1016/j.talanta.2010.08.006] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2010] [Revised: 08/05/2010] [Accepted: 08/07/2010] [Indexed: 11/24/2022]
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10
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Wu Y, Wu Q, Wang X, Xie Z, Wu X. [Rapid analysis of trace levels of riboflavin and its derivatives with hydrophilic interaction monolith by pressurized capillary electrochromatography with laser induced fluorescence detection]. Se Pu 2010; 28:247-52. [PMID: 20549975 DOI: 10.3724/sp.j.1123.2010.00247] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
Abstract
A novel hydrophilic interaction capillary electrochromatographic (HI-CEC) monolith with covalently bonded zwitterionic functional groups was applied for the separation of riboflavins (RF) and its derivatives. With a homemade pressurized capillary electrochromatography-laser induced fluorescence detection (pCEC-LIF) system, trace levels of RF and its derivatives, flavin mononucleotide (FMN) and flavin adenine dinucleotide (FAD), can be baseline separated within 8.0 min in isocratic elution mode. The effect of experimental parameters on separation was investigated. Under the optimum conditions, analytes could be determined over nearly three orders of magnitudes with the detection limits (LODs) as low as 5.0 x 10(-11) mol/L (RF), 8.0 x 10(-10) mol/L (FMN), 2.5 x 10(-9) mol/L (FAD), and the relative standard deviations (RSDs) were less than 8.2%. This method is rapid, simple, repeatable and more sensitive than the most of reported methods, and satisfied results has been achieved in serum sample. Furthermore, it can be further applied for trace analysis of RF and its derivatives in biological fluid and cells.
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Affiliation(s)
- Yimin Wu
- College of Chemistry and Chemical Engineering, Fuzhou University, Fuzhou 350108, China
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11
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Feng R, Tian Y, Chen H, Huang Z, Zeng Z. Terminal-vinyl liquid crystal crown ether-modified, vinyl-functionalized hybrid silica monolith for capillary electrochromatography. Electrophoresis 2010; 31:1975-82. [DOI: 10.1002/elps.200900627] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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12
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Abstract
Although there are many publications related to technological or methodological developments of CEC, few focus on the analysis of natural products, especially phytochemical bioactive compounds. This review summarized the application of CEC in the analysis of phytochemical bioactive components, including flavonoids, nucleosides, steroids, lignans, quinones and coumarins, as well as fingerprint analysis of herbs. The strategies for optimization of CEC conditions and detection were also discussed.
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Affiliation(s)
- Feng-qing Yang
- Department of Pharmaceutics, College of Chemistry and Chemical Engineering, Chongqing University, Chongqing, P. R. China
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13
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Nischang I, Tallarek U. Inherent peak compression of charged analytes in electrochromatography. J Sep Sci 2010; 32:3157-68. [PMID: 19746396 DOI: 10.1002/jssc.200900436] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
This work resolves peak compression of charged analytes in CEC with strong cation-exchange stationary phase particles. By combining electrochromatographic peak shape analysis with the results of numerical simulations and confocal laser scanning microscopy in the packed capillaries, we identify electrical field-induced concentration polarization as the key physical phenomenon responsible for the inherent existence of local electrical field gradients on the scale of an individual support particle. Consequently, positive and negative field gradients exist between and inside the particles along the whole packing. Their intensity depends on the particles cation-selectivity (governed by the particles volume charge density and the mobile phase ionic strength) and the applied field strength. The interplay of these local field gradients with the analytes retention (intraparticle adsorption) determines whether fronting, tailing, or spiked analyte peaks are observed, and it provides a mechanism by which strongly retained analytes can be eluted over long distances with little zone dispersion. Our analysis explains the "anomalous" peak compression effects with strong cation-exchange particles, which have been reported more than a decade ago (Smith, N. W., Evans, M. B., Chromatographia 1995, 41, 197-203) and since then remained largely unresolved.
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Affiliation(s)
- Ivo Nischang
- Department of Chemistry, Philipps-Universität Marburg, Marburg, Germany
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14
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Sedláková P, Eckhardt A, Lacinová K, Pataridis S, MiksÌÃk I, Král V, KasÌicÌka VÃ. Separation of tryptic peptides of native and glycated BSA using open-tubular CEC with salopheneâlanthanideâZn2+complex as stationary phase. J Sep Sci 2009; 32:3930-5. [DOI: 10.1002/jssc.200900513] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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15
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Chen X, Zhao J, Meng Q, Li S, Wang Y. Simultaneous determination of five flavonoids in licorice using pressurized liquid extraction and capillary electrochromatography coupled with peak suppression diode array detection. J Chromatogr A 2009; 1216:7329-35. [DOI: 10.1016/j.chroma.2009.08.034] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2009] [Revised: 08/10/2009] [Accepted: 08/12/2009] [Indexed: 11/29/2022]
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16
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Mai TD, Pham HV, Hauser PC. Capillary electrochromatography with contactless conductivity detection for the determination of some inorganic and organic cations using monolithic octadecylsilica columns. Anal Chim Acta 2009; 653:228-33. [DOI: 10.1016/j.aca.2009.09.014] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2009] [Revised: 08/19/2009] [Accepted: 09/08/2009] [Indexed: 12/01/2022]
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17
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Lerma-García MJ, Simó-Alfonso EF, Ramis-Ramos G, Herrero-Martínez JM. Rapid determination of sterols in vegetable oils by CEC using methacrylate ester-based monolithic columns. Electrophoresis 2008; 29:4603-11. [DOI: 10.1002/elps.200800247] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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18
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Karenga S, El Rassi Z. Neutral octadecyl monolith for reversed phase capillary electrochromatography of a wide range of solutes. J Sep Sci 2008; 31:2677-85. [PMID: 18693309 DOI: 10.1002/jssc.200800310] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
A neutral octadecyl monolithic (ODM) column for RP capillary electrochromatography (RP-CEC) has been developed. The ODM column was prepared by the in situ polymerization of octadecyl acrylate (ODA) as the monomer and trimethylolpropanetrimethacrylate (TRIM) as the crosslinker, in a ternary porogenic solvent containing cyclohexanol, ethylene glycol, and water. The ODM column exhibited cathodal EOF over a wide range of pH and ACN concentration in the mobile phase despite the fact that it was devoid of any fixed charges. It is believed that the EOF is due to the adsorption of ions from the mobile phase onto the surface of the monolith thus imparting to the neutral ODM column the zeta potential necessary to support the EOF required for mass transport across the monolithic column. Furthermore, the adsorption of mobile phase ions to the neutral monolith modulated solute retention and affected the separation selectivity. The wide applications of the neutral ODM column were demonstrated by its ability to separate a wide range of small and large solutes, both neutral and charged. While the separation of the neutral solutes was based on RP retention mechanism, the charged solutes were separated on the basis of their electrophoretic mobility and hydrophobic interaction with the C18 ligands of the stationary phase. As a typical result, the neutral monolithic column was able to separate peptides quite rapidly with a separation efficiency of nearly 200,000 plates/m, and this efficiency was exploited in tryptic peptide mapping of standard proteins, e. g., lysozyme and cytochrome C, by isocratic elution.
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Affiliation(s)
- Samuel Karenga
- Department of Chemistry, Oklahoma State University, OK 74075, USA
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19
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Aturki Z, Fanali S, D'Orazio G, Rocco A, Rosati C. Analysis of phenolic compounds in extra virgin olive oil by using reversed-phase capillary electrochromatography. Electrophoresis 2008; 29:1643-50. [PMID: 18383030 DOI: 10.1002/elps.200700547] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
In this work, the simultaneous separation of ten phenolic compounds (protocatechuic, p-coumaric, o-coumaric, vanillic, ferulic, caffeic, syringic acids, hydroxytyrosol, tyrosol and oleuropein) in extra virgin olive oils (EVOOs) by isocratic RP CEC is proposed. A CEC method was optimized in order to completely resolve all the analyzed compounds by studying several experimental parameters. The influence of the stationary phase type (C(18) and C(8) modified silica gel), buffer concentration and pH as well as the organic modifier content of the mobile phase on retention factors, selectivity and efficiency were evaluated in details. A capillary column packed with Cogent bidentate C(18) particles for 23 cm and a mobile phase composed by 100 mM ammonium formate buffer pH 3/H(2)O/ACN (5:65:30 v/v/v) allowed the baseline resolution of the compounds under study in less than 35 min setting the applied voltage and temperature at 22 kV and 20 degrees C, respectively. A study, evaluating the intra- and interday precision as well as LOD and LOQ and method linearity was developed in accordance with the analytical procedures for method validation. LODs were in the range of 0.015-2.5 microg/mL, while calibration curves showed a good linearity (r(2) >0.997). The CEC method was applied to the separation and determination of these compounds in EVOO samples after a suitable liquid-liquid extraction procedure. The mean recovery values of the studied compounds ranged between 87 and 99%.
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Affiliation(s)
- Zeineb Aturki
- Istituto di Metodologie Chimiche, Consiglio Nazionale delle Ricerche, Monterotondo Scalo, Rome, Italy.
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20
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Chen XJ, Ji H, Wang YT, Li SP. Simultaneous determination of seven flavonoids in Epimedium using pressurized liquid extraction and capillary electrochromatography. J Sep Sci 2008; 31:881-7. [PMID: 18293424 DOI: 10.1002/jssc.200700615] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Herba Epimedii (known as Yinyanghuo in China) is one of the commonly used Chinese medicines. Flavonoids are considered as its active components. In this study, a CEC method was developed for the simultaneous determination of seven flavonoids, including hexandraside E, kaempferol-3-O-rhamnoside, hexandraside F, icariin, epimedin A, B, and C, in Epimedium using baicalein as internal standard (IS). The influence of relevant parameters such as buffer concentration, pH, and proportion of ACN was investigated and optimized. Baseline separation was obtained using a Hypersil C18 capillary (3 microm, 100 microm/25 cm) with a mixture of 20 mM phosphate buffer (pH 4.0)/ACN (70:30 v/v) as mobile phase running at 30 kV and 25 degrees C in 20 min. All calibration curves showed good linearity (r2 >0.9992) within test ranges. The LOD and LOQ were lower than 8.6 and 42.8 microg/mL, respectively. The RSDs of intra- and interday for relative peak areas of seven analytes were less than 3.1 and 4.4%, and the recoveries were 95.2-103.3%. Samples of different Epimedium species were analyzed using the validated method, which is useful for quality control of Epimedium and its medical preparations.
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Affiliation(s)
- Xiao-jia Chen
- Institute of Chinese Medical Sciences, University of Macau, Macao SAR, China
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21
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Rocco A, Fanali S. Capillary electrochromatography without external pressure assistance. J Chromatogr A 2008; 1191:263-7. [DOI: 10.1016/j.chroma.2007.09.059] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2007] [Revised: 09/21/2007] [Accepted: 09/25/2007] [Indexed: 10/22/2022]
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22
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Blas M, McCord BR. Determination of trace levels of benzodiazepine in urine using capillary electrochromatography-time of flight mass spectrometry. Electrophoresis 2008; 29:2182-92. [DOI: 10.1002/elps.200700422] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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23
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Preinerstorfer B, Hoffmann C, Lubda D, Lämmerhofer M, Lindner W. Enantioselective silica-based monoliths modified with a novel aminosulfonic acid-derived strong cation exchanger for electrically driven and pressure-driven capillary chromatography. Electrophoresis 2008; 29:1626-37. [DOI: 10.1002/elps.200700525] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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24
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Priego-Capote F, Ye L, Shakil S, Shamsi SA, Nilsson S. Monoclonal behavior of molecularly imprinted polymer nanoparticles in capillary electrochromatography. Anal Chem 2008; 80:2881-7. [PMID: 18336010 DOI: 10.1021/ac070038v] [Citation(s) in RCA: 105] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
A new approach based on miniemulsion polymerization is demonstrated for synthesis of molecularly imprinted nanoparticles (MIP-NP; 30-150 nm) with "monoclonal" binding behavior. The performance of the MIP nanoparticles is characterized with partial filling capillary electrochromatography, for the analysis of rac-propranolol, where (S)-propranolol is used as a template. In contrast to previous HPLC and CEC methods based on the use of MIPs, there is no apparent tailing for the enantiomer peaks, and baseline separation with 25,000-60,000 plate number is achieved. These effects are attributed to reduction of the MIP site heterogeneity by means of peripheral location of the core cross-linked NP and to MIP-binding sites with the same ordered radial orientation. This new MIP approach is based on the substitution of the functional monomers with a surfactant monomer, sodium N-undecenoyl glycinate (SUG) for improved inclusion in the MIP-NP structure and to the use of a miniemulsion in the MIP-NP synthesis. The feasibility of working primarily with aqueous electrolytes (10 mM phosphate with a 20% acetonitrile at pH 7) is attributable to the micellar character of the MIP-NPs, provided by the inclusion of the SUG monomers in the structure. To our knowledge this is the first example of "monoclonal" MIP-NPs incorporated in CEC separations of drug enantiomers.
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Affiliation(s)
- Feliciano Priego-Capote
- Department of Analytical Chemistry, Córdoba University, Annex C-3 Building, Campus of Rabanales, E-14071 Córdoba, Spain
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25
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Jungbauer A, Hahn R. Polymethacrylate monoliths for preparative and industrial separation of biomolecular assemblies. J Chromatogr A 2008; 1184:62-79. [DOI: 10.1016/j.chroma.2007.12.087] [Citation(s) in RCA: 182] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2007] [Revised: 12/04/2007] [Accepted: 12/19/2007] [Indexed: 11/28/2022]
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26
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11 The need for CE methods in pharmacopoeial monographs. ACTA ACUST UNITED AC 2008. [DOI: 10.1016/s0149-6395(07)00011-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register]
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27
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García-Cañas V, Cifuentes A. Recent advances in the application of capillary electromigration methods for food analysis. Electrophoresis 2008; 29:294-309. [DOI: 10.1002/elps.200700438] [Citation(s) in RCA: 88] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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28
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Dabek-Zlotorzynska E, Celo V, Yassine MM. Recent advances in CE and CEC of pollutants. Electrophoresis 2008; 29:310-23. [DOI: 10.1002/elps.200700510] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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29
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30
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31
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Lerma-García MJ, Simó-Alfonso EF, Ramis-Ramos G, Herrero-Martínez JM. Determination of tocopherols in vegetable oils by CEC using methacrylate ester-based monolithic columns. Electrophoresis 2007; 28:4128-35. [DOI: 10.1002/elps.200700195] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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32
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Timerbaev AR. Recent trends in CE of inorganic ions: From individual to multiple elemental species analysis. Electrophoresis 2007; 28:3420-35. [PMID: 17768723 DOI: 10.1002/elps.200600491] [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] [Indexed: 01/20/2023]
Abstract
The major methodological developments in CE related to inorganic analysis are overviewed. This is an update to a previous review article by the author (Timerbaev, A. R., Electrophoresis 2004, 25, 4008-4031) and it covers the review work and innovative research papers published between January 2004 and the first part of 2006. As was underlined in that review, a growing interest of analytical community in providing elemental speciation information found a sound response of the CE method developers. Presently, almost every second research paper in the field of interest deals with element species analysis, the use of inductively coupled plasma MS detection and biochemical applications being the topics of utmost research efforts. On the other hand, advances in general methodology traditionally centered on a CE system modernization for improvements in sensitivity and separation selectivity have attracted less attention over the review period. While there is no indication that inorganic ion applications would surpass by the developmental rate the more matured analysis of organic analytes, CE can now be seen as an analytical technique to be before long customary in a number of inorganic analysis arenas.
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Affiliation(s)
- Andrei R Timerbaev
- Vernadsky Institute of Geochemistry and Analytical Chemistry, Russian Academy of Sciences, Moscow, Russia.
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33
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Lin J, Wu X, Lin X, Xie Z. Preparation of polymethacrylate monolithic stationary phases having bonded octadecyl ligands and sulfonate groups: electrochromatographic characterization and application to the separation of polar solutes for pressurized capillary electrochromatography. J Chromatogr A 2007; 1169:220-7. [PMID: 17875313 DOI: 10.1016/j.chroma.2007.08.061] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2007] [Revised: 08/26/2007] [Accepted: 08/30/2007] [Indexed: 10/22/2022]
Abstract
In this report, the preparation of porous polymethacrylate-based monolithic columns by in situ copolymerization of octadecyl methacrylate (OMA), 3-sulfopropyl methacrylate (SPMA) and ethylene dimethacrylate (EDMA) in a binary porogenic solvent consisting of cyclohexanol/1,4-butanediol are proposed. These monoliths possess in their structures bonded octadecyl ligands and sulfonate groups and are evaluated in pressurized capillary electrochromatography (pCEC) system using small neutral and charged solutes. While the sulfonate groups are meant to generate the electroosmotic flow (EOF) necessary for transporting the mobile phase through the monolithic capillary; the octadecyl ligands are introduced to provide the nonpolar sites for chromatographic retention for neutral solutes. However, incorporating the sulfonate groups in the monoliths does not only support the EOF but also exhibit hydrophilic interaction as well as electrostatic interaction/repulsion with the monoliths in addition to electrophoretic migration with polar charged solutes (e.g., nucleotides). The monolithic stationary phases at different EOF velocities are easily prepared by altering the amount of SPMA in the polymerization solution as well as the composition of the porogenic solvent. Optimum EOF velocity, the highest efficiency and adequate chromatographic retention are obtained when 0.6% SPMA is added to the reaction mixture. Under these conditions, rapid separation and high plate counts reaching greater than 170,000 plates/m are readily obtained.
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Affiliation(s)
- Jian Lin
- Department of Chemistry, Fuzhou University, Fuzhou 350002, China
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Abstract
This review summarizes applications of CEC for the analysis of proteins and peptides. This "hybrid" technique is useful for the analysis of a broad spectrum of proteins and peptides and is a complementary approach to liquid chromatographic and capillary electrophoretic analysis. All modes of CEC are described--granular packed columns, monolithic stationary phases as well as open-tubular CEC. Attention is also paid to pressurized CEC and the chip-based platform.
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Affiliation(s)
- Ivan Miksík
- Institute of Physiology, Academy of Sciences of the Czech Republic, Prague, Czech Republic.
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Yang FQ, Li S, Li P, Wang YT. Optimization of CEC for simultaneous determination of eleven nucleosides and nucleobases inCordyceps using central composite design. Electrophoresis 2007; 28:1681-8. [PMID: 17464961 DOI: 10.1002/elps.200600416] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
A CEC method is described for the simultaneous determination of 11 nucleosides and nucleobases including cytosine, uracil, uridine, hypoxanthine, 2'-deoxyuridine, inosine, guanosine, thymidine, adenine, adenosine, and cordycepin in Cordyceps using 5-chlorocytosine arabinoside as internal standard (IS). Chemometric optimization based on central composite design was employed to find the optimum conditions. The factors for optimization were defined as three parameters: voltage, pH, and concentration of ACN as organic modifier. The resolution (R(s)) between inosine and guanosine, as well as the entire run time were employed to evaluate the response function. A running buffer composed of 4 mM ammonium acetate and 2 mM triethylamine (TEA) adjusted to pH 5.3 using acetic acid, and containing 3% ACN as modifier, with gradient voltage (0-4 min: 20 kV, 4-12 min: linear gradient from 20 to 30 kV; 12-16 min: 30 kV) were found to be the optimum conditions for the separation. Separation of the 11 investigated compounds and 5-chlorocytosine arabinoside was achieved within 16 min. The contents of the 11 compounds in natural and cultured Cordyceps sinensis, and cultured Cordyceps militaris were also compared. The result showed that CEC is an efficient method for analysis of nucleosides and nucleobases in Cordyceps, which is helpful to control the quality of this valued traditional Chinese medicine.
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Affiliation(s)
- Feng Q Yang
- Institute of Chinese Medical Sciences, University of Macau, Taipa, Macau, China
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36
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Abstract
This review is concerned with the phenomenological fluid dynamics in capillary and chip electrochromatography (EC) using high-surface-area random porous media as stationary phases. Specifically, the pore space morphology of packed beds and monoliths is analyzed with respect to the nonuniformity of local and macroscopic EOF, as well as the achievable separation efficiency. It is first pointed out that the pore-level velocity profile of EOF through packed beds and monoliths is generally nonuniform. This contrasts with the plug-like EOF profile in a single homogeneous channel and is caused by a nonuniform distribution of the local electrical field strength in porous media due to the continuously converging and diverging pores. Wall effects of geometrical and electrokinetic nature form another origin for EOF nonuniformities in packed beds which are caused by packing hard particles against a hard wall with different zeta potential. The influence of the resulting, systematic porosity fluctuations close to the confining wall over a distance of a few particle diameters becomes aggravated at low column-to-particle diameter ratio. Due to the hierarchical structure of the pore space in packed beds and silica-based monoliths which are characterized by discrete intraparticle (intraskeleton) mesoporous and interparticle (interskeleton) macroporous spatial domains, charge-selective transport prevails within the porous particles and the monolith skeleton under most general conditions. It forms the basis for electrical field-induced concentration polarization (CP). Simultaneously, a finite and -- depending on morphology -- often significant perfusive EOF is realized in these hierarchically structured materials. The data collected in this review show that the existence of CP and its relative intensity compared to perfusive EOF form fundamental ingredients which tune the fluid dynamics in EC employing monoliths and packed beds as stationary phases. This addresses the (electro)hydrodynamics, associated hydrodynamic dispersion, as well as the migration and retention of charged analytes.
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Affiliation(s)
- Ivo Nischang
- Institut für Verfahrenstechnik, Otto-von-Guericke-Universität, Magdeburg, Germany
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Affiliation(s)
- R K Gilpin
- Brehm Research Laboratory, University Park, Wright State University, Fairborn, Ohio 45324-2031, USA
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Li P, Li SP, Yang FQ, Wang YT. Simultaneous determination of four tanshinones insalvia miltiorrhiza by pressurized liquid extraction and capillary electrochromatography. J Sep Sci 2007; 30:900-5. [PMID: 17536735 DOI: 10.1002/jssc.200600368] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
A pressurized liquid extraction (PLE) and CEC were developed for the simultaneous determination of four tanshinones (dihydrotanshinone I, cryptotanshinone, tanshinone I, and tanshinone IIA) in Salvia miltiorrhiza. High extraction efficiency (>98.5%) was achieved under the optimum PLE conditions. A good separation was obtained by using a Hypersil C18 capillary (3 microm, 100 microm/25 cm) with a mixture of 30 mM Tris-HCl (pH 8.5)-ACN (1:3, v/v) as BGE solution running at 20 kV and 20 degrees C within 12 min. All the calibration curves showed good linearity (r2 >0.9958) within test ranges. The developed method showed good repeatability for the quantification of four investigated components in S. miltiorrhiza with intra- and interday variations of less than 4.4 and 6.8%, respectively. The validated method was successfully applied to quantify four tanshinones in S. miltiorrhiza, which is helpful to control the quality of S. miltiorrhiza.
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Affiliation(s)
- Peng Li
- Institute of Chinese Medical Sciences, University of Macau, Taipa, Macau, China
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Ohyama K, Kuroda N. Capillary Electrochromatography of Charged Biomolecules with Mixed‐Mode Stationary Phases. J LIQ CHROMATOGR R T 2007. [DOI: 10.1080/10826070701191128] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Affiliation(s)
- Kaname Ohyama
- a Department of Hospital Pharmacy , Nagasaki University Hospital of Medicine and Dentistry , Nagasaki , Japan
| | - Naotaka Kuroda
- b Graduate School of Biomedical Sciences, Course of Pharmaceutical Sciences, Nagasaki University , Nagasaki , Japan
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Zheng J, Rizvi SAA, Shamsi SA, Hou J. Photopolymerized Sol‐Gel Monolithic Column for Capillary Electrochromatography (CEC) and CEC Coupled to Atmospheric Pressure Photoionization Mass Spectrometry. J LIQ CHROMATOGR R T 2007. [DOI: 10.1080/10826070601034238] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Affiliation(s)
- Jie Zheng
- a Department of Chemistry , Center of Biotechnology and Drug Design, Georgia State University , Atlanta, Georgia, USA
| | - Syed A. A. Rizvi
- a Department of Chemistry , Center of Biotechnology and Drug Design, Georgia State University , Atlanta, Georgia, USA
| | - Shahab A. Shamsi
- a Department of Chemistry , Center of Biotechnology and Drug Design, Georgia State University , Atlanta, Georgia, USA
| | - Jingguo Hou
- b Department of Clinical Sciences and Administration , College of Pharmacy, University of Houston, Texas Medical Center , Houston, Texas, USA
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Mangelings D, Saevels J, Vander Heyden Y. Enantiomeric impurity determination of levetiracetam using capillary electrochromatography. J Sep Sci 2006; 29:2827-36. [PMID: 17305245 DOI: 10.1002/jssc.200600190] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
CEC was used to develop a method for the enantiomeric excess determination of levetiracetam, an antiepileptic drug. Different types of calibration curve were evaluated for use in the range between 0.01 and 1 mg/mL when aniracetam was used as an internal standard. The method gave comparable results when only the areas of the impurity were used in the calibration curve. The predicted detection and quantification limits from the S/N were 1.1 and 3.6 microg/mL, respectively. However, experimental results showed that LOD and LOQ were underestimated. Repeatability of injection was demonstrated by the RSD values obtained for retention time, resolution, ratios of the areas impurity/internal standard, and areas of impurity and internal standard individually, which were below or equal to 9.30%. The between-days variability experiments indicated that it is better to make a calibration curve daily. The finally selected calibration curves were used to test the accuracy of the developed method on bulk samples and Keppra tablets containing 250 mg levetiracetam. Both selected calibration curves performed similarly. The one using the internal standard information gave overall recoveries between 88 and 118%, while the one using areas gave results between 84 and 118%.
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Affiliation(s)
- Debby Mangelings
- Department of Analytical Chemistry and Pharmaceutical Technology, Vrije Universiteit Brussel-VUB, Laarbeeklaan, Brussels, Belgium
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Zhong H, El Rassi Z. Capillary electrochromatography with monolithic silica columns. V. Study of the electrochromatographic behaviors of polar compounds on monolithic silica having surface bound cyano functionalities. J Sep Sci 2006; 29:2023-30. [PMID: 17017015 DOI: 10.1002/jssc.200600075] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
In this report, a novel polar monolithic capillary column is described for normal phase CEC (NP-CEC) of representative polar compounds including mono- and oligosaccharides, peptides, and basic drugs. The polar monolithic column, which was described in detail in the preceding paper, consisted of silica-based monolith bonded with 1H-imidazole-4,5-dicarbonitrile (IDCN) and is denoted as 2CN-OH-Monolith. Various retention parameters for neutral polar solutes (e.g., mono- and oligosaccharides) and charged polar solutes (e.g., peptides and basic drugs) were evaluated over a wide-range of elution conditions. These retention parameters yielded quantitative assessment for the polar interactions between the model solutes and the stationary phase under investigation as well as the effect of electromigration of charged solutes on their overall migration in NP-CEC. Furthermore, this investigation demonstrated that despite the possibility of achieving isocratic separation in NP-CEC for widely differing polar species, multistep-gradient elution in NP-CEC is preferred to bring about the rapid separation of a large number of polar species in a single run.
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Affiliation(s)
- Hengwen Zhong
- Department of Chemistry, Oklahoma State University, Stillwater, OK 74078-3071, USA.
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