Separation methods micellar electrokinetic chromatograph

A micellar electrokinetic chromatographic method allows the separation of optically isomeric diltiazem hydrochloride using bile salts as chiral surfactants. The chiral separation of diltiazem hydrochloride from several analogs is achieved at ambient temperature using 0.05M sodium taurodeoxycholate in a 0.02M aqueous phosphate-borate buffer solution of pH 7.0. Separation is performed using a fused-silica capillary tube (650 mm x 50 mm I.D.) and a voltage up to +25 kV. Detection is achieved on-column using UV adsorption at 210 nm (31). 

Separation of kavalactones was also achieved by supercritical fluid chromatography using methanol-modified carbon dioxide as the mobile phase. An optimal separation was achieved on either an amino or protein C4 column at 125 atm and 80 °C. Semipreparative separation of kavalactones was also obtained with two columns connected in series (Ashraf-Khorassani etal., 1999). A micellar electrokinetic chromatographic method with diode-array detection has also been developed for the identification and quantitative determination of the major kavalactones from extracts of P. methysticum... 

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. 

Chromatographic and related electrophoretic methods for the separation of transition metal complexes or their ligands were reviewed . Micellar electrokinetic chromatography (MEKC) presents a new development in the field of capillary zone electrophoresis (CZE). The use of micellar solutions expands the application of CZE to electronically neutral solutes, as well as charged ones. Thus, electrically neutral / -diketonates Cr(dik)3, Co(dik)3, Rd(dik)3, Pt(dik)2 and Pd(dik)2 were separated by CZE in micellar solutions of sds. A linear log-log relationship was found between the distribution coefficient and the partition coefficient of the complex between dodecane and water, which was used for prediction of both the distribution coefficients and the migration times of different metal complexes . 

Various papers related to the simultaneous determination of creatinine and uric acid can be found in the hterature. Several authors have developed capillary zone electrophoresis (CZE) methods for simultaneous analysis of these compounds in urine. The CE analysis of these renal markers offers some advantages when compared with chromatography, such as shortened separation time, reduced reagent consumption, and increased resolution. Capillar micellar electrokinetic chromatography has been applied to the simultaneous separation of creatinine and uric acid in human plasma and urine. However, chromatographic techniques are widely accepted for the determination of these compounds. Reversed-phase and ion... 

A micellar electrokinetic capillary chromatographic (MECC) method to separate 17 dihydroergotoxines, aci-alkaloids, and oxidation products has been described [103]. The authors used novel cationic dimeric (Gemini) surfactants such as l,3-bis(dodecyl-W,N-dimethyl ammonium)-2-propanol and l,3-bis(te-tradecyl-N,N-dimethyl ammonium)-2-propanol for the separation in less than 8 min. 

However, additives are normally combined to complement and promote their activity as a result, it is necessary to develop analytical methods for the determination of additive mixtures. Although some spectroscopic and chemical methods are used, it is preferable to use separation methods for this purpose. Most analytical methods used to determine food additives are based on chromatographic techniques, although several recent papers have demonstrated the usefulness of electrophoresis for the analysis of food colors, sweeteners, antioxidants, and/or preservatives. The separation of food colors has received most attention, with a number of articles published on both capillary zone electrophoresis and micellar electrokinetic chromatography. 

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