Chromatography dextrin

Ion-exchange chromatography such as carboxy methyl cellulose (CMC), agarose and/or dextrins... 

For obvious reasons CDs (and other dextrins) are potentially good chiral selectors for chromatography on the one hand they can be used as mobile phase additives (CMPA) in TLC45, HPLC46 and CE47 49 and on the other they can be covalently bonded onto solid supports50,51 and silica gei 52- 54 xhis approach can be extended to the preparative resolution of enantiomers41,55,56. 

Capillary gas chromatography (GC) using modified cyclodextrins as chiral stationary phases is the preferred method for the separation of volatile enantiomers. Fused-silica capillary columns coated with several alkyl or aryl a-cyclo-dextrin, -cyclodextrin and y-cyclodextrin derivatives are suitable to separate most of the volatile chiral compounds. Multidimensional GC (MDGC)-mass spectrometry (MS) allows the separation of essential oil components on an achiral normal phase column and through heart-cutting techniques, the separated components are led to a chiral column for enantiomeric separation. The mass detector ensures the correct identification of the separated components [73]. Preparative chiral GC is suitable for the isolation of enantiomers [5, 73]. 

A recent study has been performed on various spray dried orange flavors(20% oil fixed in the powder) encapsulated on various Acacia gums and on mixtures of Acacia gums and malto-dextrins. The aromas in powder were tested by chromatography and then examined by electronic microscopy. This clearly shows the regular and uniform film covering each particle 10 to 40 microns in diameter. Prints of broken particles reveal numerous oil droplets (1 micron in diameter) spread in a gum nucleus. Protection of the oil phase then becomes fully effective. 

Specific hydrolysis products obtained from both cellulose and cello-dextrins by cellobiohydrolase and endoglucanases were analyzed by low pressure liquid chromatography using water as the sole eluent (25,40). 

The preparative-scale enantiomeric separations of enflurane, isoflurane and desflurane (cf. Figure 16) by gas chromatography on modified cyclo-dextrins have been achieved. The separation was aided by unprecedentedly large separation factors a of the enantiomers. Two approaches were followed. 

Konig, W. A., Krebber, R., and Mischnick, P. (1989) Cyclodextrins as chiral stationary phases in capillary gas chromatography. Part V octakis(3-0-butyryl-2,6-di-0-pentyl)-7-cyclo-dextrin. J. High Resol. Chromatogr. 12, 732-738,... 

Maguire, J.H., Some structural requirements for resolution of hydantoin enantiomers with a-cyclo-dextrin liquid chromatography column, J. Chromatogr., 387, 453, 1987. 

Octakis (2,3,6-tri-0-methyl-gamma-cyclodextrin) was used to separate enantiomers of methyl esters of deltametrinic acid and permetrinic acid the positional isomers of nitrotoluene were also separated on the same column [17,18]. Various alkyl- and dialkyl-benzenes have been separated on beta- and gamma-cyclodextrin [19]. A complete review of the use of cyclodextrins in chromatography has been published by Hinze [20]. Cyclo-dextrins have been analyzed by packed-column gas chromatography as their dimethylsilyl ethers [21]. 

Fig. 8.—Chromatography of a Mixture of Mono- to Hexa-saccharides from an Acid Hydrolyzate of a Schardinger Dextrin. [The Adsorbent was Carbon (Darco G-60) Pretreated with 1% Ethanolic Stearic Acid the Developer was Gradually Changed from 0% to 15% Ethanol.]...

As in the case of chromatography, a chiral selector is also required in CE for enantiomeric resolution. Generally, suitable chiral compounds are used in the background electrolyte (BGE) as additives and hence are called chiral selectors or chiral BGE additives. There are only a few publications available that deal with the chiral resolution on a capillary coated with the chiral selector in CE. The analysis of the chiral pollutants discussed in this chapter is restricted only to using chiral selectors in the BGE. The most commonly used chiral BGE additives are cyclo-dextrins, macrocyclic glycopeptide antibiotics, proteins, crown ethers, ligand exchangers, and alkaloids.A list of these chiral BGE additives is presented in Table 1. 

Paper Chromatography, Optical Rotation, and Miscellaneous Observations Bearing on the Molecular Size of the Schardinger Dextrins.241... 

SE Lucangioli, LG Hermida, VP Tripodi, VPT Rodriguez, EE Lopez, PD Rouge, CN Carducci. Analysis of cis-trans isomers and enantiomers of sertraline by cyclo-dextrin-modified micellar electrokinetic chromatography. J Chromatogr A 871 207-215, 2000. 

Smith and coworkers - have subjected starch dextrins to the classical techniques of structural carbohydrate chemistry. In one study, four commercial maize-dextrins were fractionated from aqueous ethanol to obtain a sub-fraction which was the most resistant to periodate oxidation. This material was then methylated, the product hydrolyzed, and the resulting methylated sugars analyzed by column chromatography. Table II shows the results. The complexity of the dextrin structure is shown by the fact that only components 1, 2, and 5 arise in any large proportion from the methylation of maize starch. It is of interest that no traces of a methyl... 

Results of Column Chromatography of Hydrolyzate of Methylated, Maize-Starch Dextrin ... 

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