Capillary electrophoresis amino acids

Waldron, K. C. and Dovichi, N. J., Sub-femtomole determination of phenylthiohydantoin-amino acids Capillary electrophoresis and thermooptic detection. Ana/. Chem., 64,1396,1992. 

Capillary zone electrophoresis with microchip-based SCCE has been used to separate fluorescent dye from degradation products and to separate fluorescein isothiocyanate (FITC) labeled amino acids. Capillary zone electrophoresis (CZE) in fused-silica capillaries has been used to separate the racemic mixtures of (a-hydroxybenzyl)methyltrimethylammonium and (2-hydroxy-l-phenyl)ethyltrimethylammonium with f)-cyclodextrin as the chiral pseudo-stationary phase. L-Phenylalanine and L-phenylalanine-ring-D5 (the hydrogens in the aromatic ring were substituted with deuterium) and another separation of the closely related amino acids phenylalanine and tyrosine have been resolved using CZE with capillary-based SCCE. ... 

Weber, P. L. Buck, D. R. Capillary Electrophoresis A Past and Simple Method for the Determination of the Amino Acid Composition of Proteins, /. Chem. Educ. 1994, 71, 609-612. This experiment describes a method for determining the amino acid composition of cyctochrome c and lysozyme. The proteins are hydrolyzed in acid, and an internal standard of a-aminoadipic acid is added. Derivatization with naphthalene-2,3-dicarboxaldehyde gives derivatives that absorb at 420 nm. Separation is by MEKC using a buffer solution of 50 mM SDS in 20 mM sodium borate. 

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

Biomolecule Separations. Advances in chemical separation techniques such as capillary zone electrophoresis (cze) and sedimentation field flow fractionation (sfff) allow for the isolation of nanogram quantities of amino acids and proteins, as weU as the characterization of large biomolecules (63—68) (see Biopolymers, analytical techniques). The two aforementioned techniques, as weU as chromatography and centrifugation, ate all based upon the differential migration of materials. Trends in the area of separations are toward the manipulation of smaller sample volumes, more rapid purification and analysis of materials, higher resolution of complex mixtures, milder conditions, and higher recovery (69). 

Vayaboury W, Giani O, Cottet FI, Bonaric S, Schue F (2008) Mechanistic study of alpha-amino acid N-carboxyanhydride (NCA) polymerization by capillary electrophoresis. Macromol Chem Phys 209 1628-1637... 

There are many proteins in the human body. A few hundreds of these compounds can be identified in urine. The qualitative determination of one or a series of proteins is performed by one of the electrophoresis techniques. Capillary electrophoresis can be automated and thus more quantified (Oda et al. 1997). Newer techniques also enable quantitative determination of proteins by gel electrophoresis (Wiedeman and Umbreit 1999). For quantitative determinations, the former method of decomposition into the constituent amino acids was followed by an automated spectropho-tometric measurement of the ninhydrin-amino add complex. Currently, a number of methods are available, induding spectrophotometry (Doumas and Peters 1997) and, most frequently, ELISAs. Small proteins can be detected by techniques such as electrophoresis, isoelectric focusing, and chromatography (Waller et al. 1989). These methods have the advantage of low detection limits. Sometimes, these methods have a lack of specifidty (cross-over reactions) and HPLC techniques are increasingly used to assess different proteins. The state-of-the-art of protein determination was mentioned by Walker (1996). 

Smith, J. T., Recent advances in amino acid analysis using capillary electrophoresis, Electrophoresis, 20, 3078, 1999. 

Fanali, S., Ossicini, L., Foret, F., and Bocek, R, Resolution of optical isomers by capillary zone electrophoresis study of enantiomeric and distereoisomeric cobalt (III) complexes with ethylenediamine and amino acid ligands, /. Microcol. Sep., 1, 190, 1989. 

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. 

Miniaturized columns have provided a decisive advantage in speed. Uracil, phenol, and benzyl alcohol were separated in 20 seconds by CEC in an 18 mm column with a propyl reversed phase.29 A19 cm electrophoretic channel was etched into a glass wafer, filled with a y-cyclodextrin buffer, and used to resolve chiral amino acids from a meteorite in 4 minutes.30 A 6 cm channel equipped with a syringe pump to automate sample derivatization was used to separate amino acids modified with fluorescein isothiocyanate.31 Nanovials have been used to perform tryptic digests on the 15 nL scale for subsequent separation on capillary Electrophoresis.32 A microcolumn has also been used to generate fractions representing time-points of digestion from a 40 pL sample.33 A disposable nanoelectrospray emitter has been... 

Hutt, L.D., Glavin, D.P., Bada, J.L., and Mathies, R.A., Microfabricated capillary electrophoresis amino acid chirality analyzer for extraterrestrial exploration, Anal. Chem. 71, 4000, 1999... 

Zahou, E., Jornvall H., and Bergman T., Amino acid analysis by capillary electrophoresis after phenylthiocarbamylation, Anal. Biochem., 281, 115, 2000. 

Capillary zone electrophoresis, an up-to-date high resolution separation method useful for proteins and peptides, has been shown to be a useful method for determining electrophoretic mobilities and diffusion coefficients of proteins [3], Diffusion coefficients can be measured from peak widths of analyte bands. The validity of the method was demonstrated by measuring the diffusion coefficients for dansylated amino acids and myoglobin. 

Tao, L., Thompson, J.T., Kennedy R.T. (1998). Optically-gated capillary electrophoresis of o-phthaldehyde/P-mercaptoethanol derivatives of amino acids for chemical monitoring. Anal. Chem. 70, 4015M022. 

Jorgenson reported the use of glass capillaries for free solution electrophoresis 25 years ago (Jorgenson andLukacs, 1981,1983). Aplug of analyte was introduced into a buffer-filled capillary and separated at high electric fields. Capillaries of 75 im inner diameter were employed, and detection of labeled amino acids and peptides was based on fluorescence. 

Heterocyclic fluorophores based on the benzoxadiazole nucleous, namely 4-nitrobenz-2-oxa-l,3-diazole (NBD) 14 derivatives/analogs, have been widely used as derivatization reagents for analysis purposes. Examples include the amino- or thiol reactive 4-fluoro-7-nitrobenz-2-oxa-l,3-diazole (NBD-F) 15 and 4-chloro-7-nitrobenz-2-oxa-1,3-diazole (NBD-C1) 16 [45-50] and the thiol-reactive /V-((2-(iodoacetoxy)ethyl)-/V-methyl)amino-7-nitrobenz-2-oxa-1,3-dia-zole (IANBD ester) 17 [51] and 7-chlorobenz-2-oxa-l,3-diazole-4-sulfonate (SBD-C1) 18 [52], NBD-F and NBD-C1 derivatives can be excited at about 470 nm by using the relatively inexpensive and reliable argon ion lasers or newer diode pumped solid state (DPSS) lasers. NBD-F has been used as a labeling tag in various capillary electrophoresis (CE) experiments for amino acids [53-57] including the monitorization of in vivo dynamics of amino acids neurotransmitters [58]. 

Zhang H, Le Potier I, Smadja C et al (2006) Fluorescent detection of peptides and amino acids for capillary electrophoresis via on-line derivatization with 4-fluoro-7-nitro-2,l, 3-benzoxadiazole. Anal Bioanal Chem 386 1387-1394... 

Klinker CC, Bowser MT (2007) 4-Fluoro-7-nitro-2, 1, 3-benzoxadiazole as a fluorogenic labeling reagent for the in vivo analysis of amino acid neurotransmitters using online microdialysis-capillary electrophoresis. Anal Chem 79 8747-8754... 

Wu S, Dovichi NJ (1989) High-sensitivity fluorescence detector for fluorescein isothiocyanate derivatives of amino acids separated by capillary zone electrophoresis. J Chromatogr 480 141-155... 

Cheng YF, Dovichi NJ (1988) Subattomole amino acid analysis by capillary zone electrophoresis and laser-induced fluorescence. Science 242 562-564... 

S.M. Harrison, I. Kami, V. Prokoratova, M. Mazanek, E. Kenndler, Characterisation and identification of proteinaceous binding media (animal glues) from their amino acid profile by capillary zone electrophoresis, Anal. Bioanal. Chem., 382, 1520 1526 (2005). 

Rutherfurd, S.M., Zhang, F., Harding, D.R., Woolhouse, A.D. and Hendriks, W.H. (2004) Use of capillary (zone) electrophoresis for determining felinine and it s application to investigate the stability of felinine. Amino Acids 27, 49-55. 

As with other chromatographic methods, there are a number of electrophoretic methods, including paper and gel electrophoreses and CE. Electrophoresis uses an electric current to move ionic species, either simple ions, amino acids, or complex proteins, through a medium (i.e., a gel) or a capillary (i.e., CE). During this process, typically, the ionic species move at different rates and are thus separated. 

K. Arlt, S. Brandt, and J. Kehr, Amino acid analysis in five pooled single plant cell samples using capillary electrophoresis coupled to laser induced fluorescence detection. J. Chromatogr. A 926, 319 325 (2001). 

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