Publisher Summary The carbohydrates are important as principal constituents of plant and bacterial cell walls, and as storage products in roots and seeds. In animal bodies, glucose, the most popular carbohydrate, circulates through the blood vessels, supplying energy to tissues. The metabolism of glucose is very complex, involving transformation to many compounds having smaller numbers of carbon atoms. Owing to the multiplicity of configurations, a monosaccharide has a number of stereoisomers with similar physico-chemical properties. Oligosaccharides and polysaccharides have additional types of isomers arising from the differences in sequence and positions of attachment of monosaccharide residues. High-resolution chromatography is essential to overcome the difficulty of separating these structurally similar sets of isomers. Gas chromatography, especially in the capillary mode, gives excellent resolution, and has been used for the analysis of monosaccharides and lower oligosaccharides. However, the samples have to be converted into volatile derivatives prior to injection, because they are difficult to vaporize.