- Carbohydrate composition
- Stereochemistry of sugar residues
- Polysaccharide linkage analysis
GC is the method of choice for glycosyl-residue identification (i.e., the sugar components that make up polysaccharides and oligosaccharides). Two basic derivitization techniques allow for the necessary volatilization and ultimate separation of each glycosyl residue that is released from the polymers by the initial acid hydrolysis. The standard alditol acetate derivitization (or acetylation) technique is highly reproducible and enables the identification of neutral sugar components. A TMS-methyl glucoside techniques expands the analysis to the acidic components, such as the galacturonic acid residues that constitute common pectin. A variation of this second technique is used to determine the d or l configuration of each sugar component.
In addition to glycosyl-residue identification, the methylation of polysaccharides prior to acid hydrolysis and acetylation facilitates the identification of the glycosyl residue linkage points. This is essential to understanding the nature and identity of the polysaccharides.