Micellar electrokinetic

Micellar Electrokinetic Capillary Chromatography One limitation to CZE is its inability to separate neutral species. Micellar electrokinetic chromatography... [Pg.606]

The elution order for neutral species in MEKC depends on the extent to which they partition into the micelles. Hydrophilic neutrals are insoluble in the micelle s hydrophobic inner environment and elute as a single band as they would in CZE. Neutral solutes that are extremely hydrophobic are completely soluble in the micelle, eluting with the micelles as a single band. Those neutral species that exist in a partition equilibrium between the buffer solution and the micelles elute between the completely hydrophilic and completely hydrophobic neutrals. Those neutral species favoring the buffer solution elute before those favoring the micelles. Micellar electrokinetic chromatography has been used to separate a wide variety of samples, including mixtures of pharmaceutical compounds, vitamins, and explosives. [Pg.606]

Kovat s retention index (p. 575) liquid-solid adsorption chromatography (p. 590) longitudinal diffusion (p. 560) loop injector (p. 584) mass spectrum (p. 571) mass transfer (p. 561) micellar electrokinetic capillary chromatography (p. 606) micelle (p. 606) mobile phase (p. 546) normal-phase chromatography (p. 580) on-column injection (p. 568) open tubular column (p. 564) packed column (p. 564) peak capacity (p. 554)... [Pg.609]

The last set of experiments provides examples of the application of capillary electrophoresis. These experiments encompass a variety of different types of samples and include examples of capillary zone electrophoresis and micellar electrokinetic chromatography. [Pg.614]

Vogt, C. Conradi, S. Rhode, E. Determination of Caffeine and Other Purine Compounds in Pood and Pharmaceuticals by Micellar Electrokinetic Chromatography, /. Chem. Educ. 1997, 74, 1126-1130. [Pg.614]

The effects of pH on electrokinetic velocities in micellar electrokinetic chromatography was studied by using sodium dodecyl sulfate solutions [179]. Micellar electrokinetic capillary chromatography with a sodium dodecyl sulfate pseudostationary phase has been used to determine the partition constants for nitrophenols, thiazolylazo dyes, and metal chelate compounds [180]. A similar technique was used to separate hydroquinone and some of its ether derivatives. This analysis is suitable for the determination of hydroquinone in skin-toning creams [181]. The ingredients of antipyretic analgesic preparations have also been determined by this technique [182], The addition of sodium dodecyl sulfate improves the peak shapes and resolution in chiral separations by micellar electrokinetic chromatography [183]. [Pg.274]

WORTH c c, wiESSLER M and SCHMITZ o J (2000) Analysis of catechins and caffeine in tea extracts by micellar electrokinetic chromatography . Electrophoresis, 21 (17), 3634-... [Pg.158]

CE was recently used for anthocyanin analysis because of its excellent resolution. This technique has different modes capillary zone electrophoresis (CZE), capillary gel electrophoresis (CGE), micellar electrokinetic chromatography (MEKC), capillary electrochromatography (CEC), capillary isoelectric focusing (CIEE), and capillary isotachophoresis (CITP)."° CZE is the most popular method for anthocyanin... [Pg.489]

Capillary electrophoresis is increasingly used in food analysis due to its separation performance combined with the short time of analysis. - CapiUary electrophoresis recently applied to colorant measurements includes technical variants such as capillary zone electrophoresis (CZE) and micellar electrokinetic chromatography. ... [Pg.523]

Watanabe, T. et al.. Analysis of elderberry pigments in commercial food samples by micellar electrokinetic chromatography. Anal. Sci., 14, 839, 1998. [Pg.527]

Micellar electrokinetic Extraction of sample in water/medianol with 214 nm Confectionery Q-... [Pg.536]

Recently a new method was developed for the complete liquid chromatographic separation and diode array detection of standard mixtures of the 14 most frequently used synthetic colorants. Protocols for RP-HPLC - " and IP-HPLC techniques have been extensively described and the techniques were compared with micellar electrokinetic capillary chromatography, - which has been shown to be suitable for the analysis of synthetic colorants. [Pg.542]

Chou, S.S. et al., Determination of synthetic colors in soft drinks and confectioneries by micellar electrokinetic capillary chromatography, J Food ScL, 67, 1314, 2002. [Pg.545]

Thompson, C.O. and Trenerry, V.C., Determination of synthetic colours in confectionery by micellar electrokinetic capillary chromatography, J. Chromatogr. A, 704, 195, 1995. [Pg.546]

Trone, M. D., Leonard, M. S., Khaledi, M. G. Congeneric behavior in estimations of octanol-water partition coefficients by micellar electrokinetic chromatography. Anal. Chem. 2000, 72, 1228-1235. [Pg.49]

A., Testa, B. The relative partitioning of neutral and ionised compounds in sodium dodecyl sulfate micelles measured by micellar electrokinetic capillary chromatography. Eur. J. Pharm. Sci. 2002, 75, 225-234. [Pg.354]

R., Khaledi, M. G. Quantitative structure-activity relationships studies with micellar electrokinetic chromatography. Influence of surfactant type and mixed micelles on estimation of hydrophobicity and bioavailability. J. Chromatogr. A 1996, 727, 323-335. [Pg.354]

S. L, Carlucci, A., Bregni, C., Kenndler, E. Comparison of the retention charaderi sties of different pseudostationary phases for microemulsion and micellar electrokinetic chromatography of betamethasone and derivatives. Electrophoresis 2003, 24, 984-991. [Pg.354]

Ferreres, F., Blazquez, M. A., Gil, M. L, and Tomas-Barberan, F. A. (1994a). Separation of honey flavonoids by micellar electrokinetic capillary chromatography. /. Chromatogr. A 669, 268-274. [Pg.127]

A variety of formats and options for different types of applications are possible in CE, such as micellar electrokinetic chromatography (MEKC), isotachophoresis (ITP), and capillary gel electrophoresis (CGE). The main applications for CE concern biochemical applications, but CE can also be useful in pesticide methods. The main problem with CE for residue analysis of small molecules has been the low sensitivity of detection in the narrow capillary used in the separation. With the development of extended detection pathlengths and special optics, absorbance detection can give reasonably low detection limits in clean samples. However, complex samples can be very difficult to analyze using capillary electrophoresis/ultraviolet detection (CE/UV). CE with laser-induced fluorescence detection can provide an extraordinarily low LOQ, but the analytes must be fluorescent with excitation peaks at common laser wavelengths for this approach to work. Derivatization of the analytes with appropriate fluorescent labels may be possible, as is done in biochemical applications, but pesticide analysis has not been such an important application to utilize such an approach. [Pg.781]

Saitoh, T., Hoshino, H., and Yotsuyanagi, T., Micellar electrokinetic capillary chromatography of porphinato chelates as a spectrophotometric approach to subfemtomole detection of metal chelates, Anal. Sci., 7, 495, 1991. [Pg.422]

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