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Polysaccharide analysis hydrophilicity

It would be easier to describe those classes of compounds not normally separated by RPLC than to catalogue the applications to which RPLC has been turned. Applications for reversed phase can be found in virtually every area of analysis and are reviewed regularly in the journal Analytical Chemistry. RPLC has not been in general use for the analysis of inorganic ions, which are readily separated by ion exchange chromatography polysaccharides, which tend to be too hydrophilic to separate by RPLC polynucleotides, which tend to adsorb irreversibly to the reversed phase packing and compounds which are so hydrophobic that reversed phase offers little selectivity. [Pg.160]

Both polymeric and silica-based columns are in common use.The polymeric columns are heavily used in the analysis of synthetic polymers and plastics where organic solvents are required. Silica-based columns with hydrophilic bonded phases are used to separate aqueous solutions of macromolecules. Finally, polymeric size-separation columns with hydrophilic phases are available for separation of polysaccharides, peptides, and very small proteins. [Pg.98]

For the analysis of water-soluble polymers (such as surfactants, oligosaccharides, PEGS, lignosulfonates, polyacrylates, polysaccharides, PVA, cellulose derivatives, PEG, polyacrylic acids, polyacrylamides, hyaluronic acids, CMC, starches, gums) and for separations of oligomers and small molecules, columns that are comprised of macroporous material with hydrophilic functionalities may be used. The requirement for these columns in SEC mode is to eliminate or minimize ionic and hydrophobic effects that make aqueous SEC (otherwise known as GFC) very demanding. The interaction of analytes with neutral, ionic, and hydrophobic moieties must be suppressed. It is often necessary to modify the eluent (addition of salt) in order to avoid sample-to-sample and sample-to-column interactions that can result in poor aqueous SEC separations and low recoveries. [Pg.272]

The application of enzymic methods to the structural analysis of polysaccharides has been reviewed. The second part of a review on the application of g.l.c. to carbohydrates includes details of methods of methylation, and has collected m.s. data for TMS, acetyl, trifluoroacetyl, and methyl derivatives of sugars. The high reactivity of methyl trifluoromethanesulphonate (methyl triflate) makes it a suitable reagent for methylation of carbohydrates under mild conditions. Since the high reactivity of this triflate limits the choice of solvent for the methylation, hydrophilic carbohydrates cannot normally be methylated by this procedure. [Pg.215]


See other pages where Polysaccharide analysis hydrophilicity is mentioned: [Pg.17]    [Pg.565]    [Pg.208]    [Pg.402]    [Pg.542]    [Pg.508]    [Pg.542]    [Pg.76]    [Pg.1869]    [Pg.274]    [Pg.230]    [Pg.237]    [Pg.433]   
See also in sourсe #XX -- [ Pg.146 ]




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