Detection capillary zone electrophoresis

Catechin and epicatechin are two flavanols of the catechin family. They are enantiomers. The capillary zone electrophoresis (CE) methods with UV-detection were developed for quantitative determination of this flavanols in green tea extracts. For this purpose following conditions were varied mnning buffers, pH and concentration of chiral additive (P-cyclodextrin was chosen as a chiral selector). Borate buffers improve selectivity of separation because borate can make complexes with ortho-dihydroxy groups on the flavanoid nucleus. 

Indirect UV absorbance detection in capillary zone electrophoresis has been used to analyze sodium alcohol sulfates. Excellent reproducibility was obtained when veronal buffer was used as UV-absorbing background electrolyte [302],... 

Very recently, HPLC with fluorescence detection was recommended for improving detection sensitivities of betalains. " While this technique may be worthwhile for betaxanthin analyses, its use for betacyanins cannot be recommended. Although this technique represents a worthwhile approach requiring low amounts of solvent and sample and generally characterized by a high separation efhciency, only one study dealt with the use of capillary zone electrophoresis for betalain analyses. ... 

Mato, 1., Huidobro, J. F., Simal-Lozano, J., and Sancho, M. T. (2006b). Simultaneous determination of nonaromatic organic acids in honey by capillary zone electrophoresis with direct UV detection. J. Agric. Food Chem. 54,1541-1550. 

Wu, S. and Dovichi, N. J., Capillary zone electrophoresis separation and laser-induced fluorescence detection of zeptomole quantities of fluorescein thiohy-dantoin derivatives of amino acids, Talanta, 39, 173, 1992. 

Wallingford, R. A. and Ewing, A. G., Capillary zone electrophoresis with electrochemical detection, Anal. Chem., 59, 1762, 1987. 

Foret, F., Fanali, S., Nardi, A., and Bocek, P., Capillary zone electrophoresis of rare earth metals with indirect UV absorbance detection, Electrophoresis, 11, 780, 1990. 

Bachmartn, K., Boden, J., and Haumann, I., Indirect fluorimetric detection of alkali and alkaline earth metal ions in capillary zone electrophoresis with cerium (III) as carrier electrolyte, /. Chromatogr., 626, 259, 1992. 

Kuhr, W. G. and Yeung, E. S., Indirect fluorescence detection of native amino acids in capillary zone electrophoresis, Anal. Chem., 60, 1832, 1988. 

Liu H., Cho B.-Y., Strong R., Krull I.S., Cohen S., Chan K.C., and Issaq H.J., Derivatization of peptides and small proteins for improved identification and detection in capillary zone electrophoresis (CZE), Anal. Chim. Acta, 400, 181, 1999. 

Olivares, J.A., Nguyen, N.T., Yonker, C.R., Smith, R.D. (1987). On-line mass spectrometric detection for capillary zone electrophoresis. Anal. Chem. 59, 1230-1232. 

Solinova V, Kasicka V, Koval D et al (2004) Analysis of synthetic derivatives of peptide hormones by capillary zone electrophoresis and micellar electrokinetic chromatography with ultraviolet-absorption and laser-induced fluorescence detection. J Chromatogr B 808 75-82... 

Capillary zone electrophoresis coupled with fast cyclic voltammetric detection was developed by Zhou et al. [27] for the separation and determination of OTC, TC, and CTC antibiotics. All compounds were well separated by optimization of pH and complexation with a boric acid sodium tetraborate buffer. The detection limit using fast on-line cyclic voltammetric detection with Hg-film-microm electrode was 1.5 x 10-6 mol/L for OTC (signal to noise ratio > 2). A continuous flow manifold coupled on-line to a capillary electrophoresis system was developed by Nozal et al. [28] for determining the trace levels of OTC, TC, and DC in surface water samples. 

Gotti et al. [42] reported an analytical study of penicillamine in pharmaceuticals by capillary zone electrophoresis. Dispersions of the drug (0.4 mg/mL for the determination of (/q-penicillaminc in water containing 0.03% of the internal standard, S -met hy I - r-cystei ne, were injected at 5 kPa for 10 seconds into the capillary (48.5 cm x 50 pm i.d., 40 cm to detector). Electrophoresis was carried out at 15 °C and 30 kV, with a pH 2.5 buffer of 50 mM potassium phosphate and detection at 200 rnn. Calibration graphs were linear for 0.2-0.6 pg/mL (detection limit = 90 pM). For a more sensitive determination of penicillamine, or for the separation of its enantiomers, a derivative was prepared. Solutions (0.5 mL, final concentration 20 pg/mL) in 10 mM phosphate buffer (pH 8) were mixed with 1 mL of methanolic 0.015% 1,1 -[ethylidenebis-(sulfonyl)]bis-benzene and, after 2 min, with 0.5 mL of pH 2.5 phosphate buffer. An internal standard (0.03% tryptophan, 0.15 mL) was added and aliquots were injected. With the same pH 2.5 buffer and detection at 220 nm, calibration graphs were linear for 9.3-37.2 pg/mL, with a detection limit of 2.5 pM. For the determination of small amounts of (L)-penicillamine impurity, the final analyte concentration was 75 pg/mL, the pH 2.5 buffer contained 5 mM beta-cyclodextrin and 30 mM (+)-camphor-10-sulfonic acid, with a voltage of 20 kV, and detection at 220 nm. Calibration graphs were linear for 0.5-2% of the toxic (L)-enantiomer, with a detection limit of 0.3%. 

Fan et al. [106] developed a high performance capillary electrophoresis method for the analysis of primaquine and its trifluoroacetyl derivative. The method is based on the mode of capillary-zone electrophoresis in the Bio-Rad HPE-100 capillary electrophoresis system effects of some factors in the electrophoretic conditions on the separation of primaquine and trifluoroacetyl primaquine were studied. Methyl ephedrine was used as the internal standard and the detection was carried out at 210 nm. A linear relationship was obtained between the ratio of peak area of sample and internal standard and corresponding concentration of sample. The relative standard deviations of migration time and the ratio of peak area of within-day and between-day for replicate injections were <0.6% and 5.0%, respectively. 

R. Loos, M.C. Alonso and D. Barcelo, Solid-phase extraction of polar hydrophilic aromatic sulfonates followed by capillary zone electrophoresis-UV absorbance detection and ion-pair liquid chromatography-diode array UV detection and electrospray mass spectrometry. J. Chromatogr.A 890 (2000) 225-237. 

Martinez D, Pocurull E, Marce RM, et al. 1996. Separation of eleven priority phenols by capillary zone electrophoresis with ultraviolet detection. J Chromatogr 734 367-373. 

In CZE, the capillary, inlet reservoir, and outlet reservoir are filled with the same electrolyte solution. This solution is variously termed background electrolyte, analysis buffer, or run buffer. In CZE, the sample is injected at the inlet end of the capillary, and components migrate toward the detection point according to their mass-to-charge ratio by the electrophoretic mobility and separations principles outlined in the preceding text. It is the simplest form of CE and the most widely used, particularly for protein separations. CZE is described in Capillary Zone Electrophoresis. ... 

Schrader, W. Linscheid, M. Styrene Oxide DNA Addncts in Vitro Reaction and Sensitive Detection of Modified Oligonn-cleotides Using Capillary Zone Electrophoresis Interfaced to ESI-MS. Archives of Toxicology 1997, 71, 588-595. 

Kaale, E., Van Schepdael, A., Roets, E., and Hoogmartens, J. (2001). Development and validation of a simple capillary zone electrophoresis method for the analysis of kanamycin sulfate with UV detection after pre-capillary derivatization. /. Chromatogr. A 924(1—2), 451—458. 

Ackermans, M. T., Everaerts, F. M., and Beckers, J. L. (1992). Determination of aminoglycoside antibiotics in pharmaceuticals by capillary zone electrophoresis with indirect UV detection coupled with micellar electrokinetic capillary chromatography.. Chromatogr. 606, 229—235. 

Fang, X. M., Ye, J. N., and Fang, Y. Z. (1996). Determination of polyhydroxy antibiotics by capillary zone electrophoresis with amperometric detection at a nickel electrode. Anal. Chim. Acta 329, 49-55. 

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