Fluorescence detection capillary zone electrophoresis

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. ... 

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. 

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

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... 

W. Wei, G. Zue, and E. S. Yeung, One-Step Concentration of Analytes Based on Dynamic Change in pH in Capillary Zone Electrophoresis, Anal. Chem. 2002, 74, 934 P. Britz-McKibbin, K. Otsuka, and S. Terabe, On-Line Focusing of Flavin Derivatives Using Dynamic pH Junction-Sweeping Capillary Electrophoresis with Laser-Induced Fluorescence Detection, Anal. Chem. 2002, 74, 3736. 

B.W. Wright, G.A. Ross and R.D. Smith, Capillary zone electrophoresis with laser fluorescence detection of marine toxins, J. Microcol. Sep., 1, 85-89 (1989). 

Chao YC, Whang CW. 1994. Capillary zone electrophoresis of eleven priority phenols with indirect fluorescence detection. J Chromatog 663 229-237. 

Direct measurement of riboflavin, FMN, and FAD in plasma or erythrocytes may be made by HPLC, usually with fluorescence detection after protein precipitation or by capillary zone electrophoresis with laser-induced fluorescence detection (CZE-LIF). In a study of riboflavin status and FMN and FAD concentrations in plasma and erythrocytes from elderly subjects at baseline and after low-dose riboflavin supplementation, using both activation coefficient measurements and CE-LIF, it was concluded that concentrations of aU Ba vitamers except plasma FAD are potential... 

Perez-Ruiz T, Martinez-Lozano C, Sanz A, Bravo E. Determination of riboflavin, flavin mononucletide and flavin adenine dinucleotide in biological tissues by capillary zone electrophoresis and laser-induced fluorescence detection. Electrophoresis 2001 22 1170-4. 

E Gonzalez, A Becerra, JJ Laserna. Direct determination of diuretic drugs in urine by capillary zone electrophoresis using fluorescence detection. J Chromatogr B 687 145-150, 1996. 

In isotachophoresis, electrical detection is most commonly used, although thermal and UV-absorption detection are also used(3). For capillary zone electrophoresis, UV-absorption and fluorescence detection have proven most useful so far. The principles behind the optical detection modes are fairly obvious. However, the electrical and thermal detectors deserve further explanation. As described earlier, in isotachophoresis, each zone is an individual "pure" band of sample ions. The zones travel in order of decreasing mobility. To compensate for each successive... 

For capillary zone electrophoresis the electrical and thermal detection modes have insufficient sensitivity. This is because in capillary zone electrophoresis there is a relatively large background of supporting electrolyte (buffer) upon which a low concentration of sample ion is superimposed. Detecting the exceedingly small changes in electrical properties or temperature associated with sample zones is difficult. Thus UV absorption and fluorescence detection have been of greatest use in capillary zone electrophoresis. 

The most widely appHed colorimetric assay for amino acids reHes upon ninhydrin-mediated color formation (129). Fluorescamine [38183-12-9] and o-phthalaldehyde [643-79-8] are popular as fluorescence reagents. The latter reagent, in conjunction with 2-mercaptoethanol, is most often used in post-column detection of amino acids separated by conventional automated amino acid analysis. More recentiy, deterrnination by capillary zone electrophoresis has been developed and it is possible to determine attomole quantities of amino acids (130). 

Roach, M. C., Gozel, P, and Zare, R. N. Determination of methotrexate and its major metabolite, 7-hydroxymethotreaxate using capillary zone electrophoresis and laser induced fluorescence detection, J. Chmmatograph., 426, 129, 1988. 

Higashijima, T., Fuchigami, T., Imasaka, T., and Ishibashi, N., Determination of amino-acids by capillary zone electrophoresis based on semiconductor-laser fluorescence detection, AnoZ. Ghent., 64, 711, 1992. 

Miller, K. J. and Lytle, F. E., Capillary zone electrophoresis with time-resolved fluorescence detection using a diode-pumped solid-state laser, J. Chromatogr., 648, 245, 1993. 

Rose, D. J. and Jorgenson, J. W., Post-capillary fluorescence detection in capillary zone electrophoresis using ortho-phthaldialdehyde, J. Chromatogr., 447,117,1988. 

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