Chiral selectors high-performance liquid

Capillary electrophoresis employing chiral selectors has been shown to be a useful analytical method to separate enantiomers. Conventionally, instrumental chiral separations have been achieved by gas chromatography and by high performance liquid chromatography.127 In recent years, there has been considerable activity in the separation and characterization of racemic pharmaceuticals by high performance capillary electrophoresis, with particular interest paid to using this technique in modem pharmaceutical analytical laboratories.128 130 The most frequently used chiral selectors in CE are cyclodextrins, crown ethers, chiral surfactants, bile acids, and protein-filled... 

In another study, the authors reported a comparative study of the enantiomeric resolution of miconazole and the other two chiral drugs by high performance liquid chromatography on various cellulose chiral columns in the normal phase mode [79], The chiral resolution of the three drugs on the columns containing different cellulose derivatives namely Chiralcel OD, OJ, OB, OK, OC, and OE in normal phase mode was described. The mobile phase used was hexane-isopropanol-diethylamine (425 74 1). The flow rates of the mobile phase used were 0.5, 1, and 1.5 mL/min. The values of the separation factor (a) of the resolved enantiomers of econazole, miconazole, and sulconazole on chiral phases were ranged from 1.07 to 2.5 while the values of resolution factors (Rs) varied from 0.17 to 3.9. The chiral recognition mechanisms between the analytes and the chiral selectors are discussed. 

Berthod, A. et al.. Evaluation of the macrocyclic glycopeptide A-40,926 as a high-performance liquid chromatographic chiral selector and comparison with teicoplanin chiral stationary phase, J. Chromatogr. A, 897, 113, 2000. 

D Acquarica, L, New synthetic strategies for the preparation of novel chiral stationary phases for high-performance liquid chromatography containing natural pool selectors, J. Pharm. Biomed. Anal, 23, 3, 2000. 

Bosakova, Z., Cufinovd, E., and Tes ovd, E., Comparison of vancomycin-based stationary phases with different chiral selector coverage for enantioselective separation of selected drugs in high-performance liquid chromatography, J. Chromatogr. A, 1088, 94, 2005. 

Tesafova, E., Bosdkovd, Z., and Zuskova, L, Enantioseparation of selected iV-tert-butyloxycarbonyl amino acids in high-performance liquid chromatography and capillary electrophoresis with a teicoplanin chiral selector. J. Chromatogr. A, 879, 147, 2000. 

DK Lloyd, A Ahmed, F Pastore. A quantitative relationship between capacity factor and selector concentration in capillary electrophoresis and high-performance liquid chromatography evidence from the enantioselective resolution of benzoin using human serum albumin as chiral selector. Electrophoresis 18 958-964, 1997. 

Using amylose tris-3,5-dimethylphenylcarbamate as the chiral selector in enantioselective high-performance liquid chromatography, micropreparative resolution of the DHA racemate was achieved and the chromatographic behaviour in enantio-GC could be defined by coinjecting these references of definite chirality (Fig. 17.4) [13]. 

Fig. 17.4 Chromatographic behaviour of dihydroactinidiolide (DHA) enantiomers synthetic racemate (a) DHA fractionation by enantioselective high-performance liquid chromatography (HPLC) (b). Chiral selectors used in enantio-GC DIME-jS-CD (30%) in SE 52 DIAC-jS-CD (30%) in PS 268 DIAC-/1-CD (50%) in OV 1701. Order of elution R (I), S (II) in all cases [13], DIME heptakis(2,3-di-0-methyl), CD cylclodextrin, DIAC heptakis(2,3-di-0-acetyl)...

Thin-Layer Chromatography. Chiral stationary phases have been used less extensively in tic as in high performance liquid chromatography (hplc). This may, in large part, be due to lack of availability. The cost of many chiral selectors, as well as the accessibility and success of chiral additives, may have inhibited widespread commercialization. Usually, nondestructive visualization of the sample spots in tic is accomplished using iodine vapor, uv or fluorescence. However, the presence of the chiral selector in the stationary phase can mask the analyte and interfere with detection (43). 

Hui, F. (2004) High Performance Liquid Chromatography and Capillary Electrophoresis Chiral Recognition Mechanisms Using Glycopeptide Macrocyclic Antibiotics as Selectors, Fenxi Huaxue 32, 964-968. 

M. Lammerhofer and W. Lindner, Quinince and quinidine derivatives as chiral selectors. Beush type chiral stationary phases for high performance liquid chromatography based on chincona carbamates and their applications as chiral anion exchanger, J. Chromatogr. 741 (1966), 33. 

La Torre, F., Sinibaldi, M. High-performance liquid chromatography on chiral packed microbore columns with the 3,5-dinitrobenzoyl derivative of trans-1,2-diaminocyclohexane as selector,... 

Maier, N. M., Rissanen, K., Lindner,W. Direct high-performance liquid chromatographic separation of peptide enantiomers Study on chiral recognition by systematic evaluation of the influence of structural features of the chiral selectors... 

Recently, optically active polythiophenes, incorporating as ring substituents chiral selectors such as (R)-(-)- and CS )-(+)-/V-(3,5-dinitrobcnzoyl)-a-phcnylglycinc used in Pirkle-type stationary phases, have been synthesized.167 These may have potential in enantioselective analysis of chiral chemicals using high performance liquid chromatography (HPLC). 

AM Abushoffa, BJ Clark. Resolution of enantiomers of oxamniquine by capillary electrophoresis and high-performance liquid chromatography with cyclodextrins and heparin as chiral selectors. J Chromatogr A 700 51-58, 1995. 

Gasparrini F, Misiti D, and Villani C (2001) High-performance liquid chromatography chiral stationary phases based on low-molecular-mass selectors. Journal of Chromatography A 906 35-50. 

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