Carbohydrate analysis by high-performance liquid chromatography (HPLC) with evaporative light-scattering detection (ELSD)

Carbohydrates are common natural products that not only function as energy reserves and as structural material in plants but also play crucial roles in many biological processes. Carbohydrates are one of the major nutrients in human diet, serve as an energy source, provide nutritional benefits, and are widely used to modify food texture and taste. Specific and accurate analyses of carbohydrates are required by food product labeling regulations and increasing consumer demand for high-quality products. The analysis of carbohydrates and their conjugates has become one of the most requested analyses in both biochemical and nutritional analytical laboratories. In this chapter, we demonstrated that short-chain carbohydrates, including monosaccharides and oligosaccharides can be sufficiently separated with hydrophilic interaction liquid chromatography (HILIC) and quantified by an evaporative light-scattering detector (ELSD). Polysaccharides can be characterized by size-exclusion chromatography (gel permeation chromatography) and detected by ELSD. As an alternative, they can also be hydrolyzed to short-chain carbohydrates and analyzed by high-performance liquid chromatography/ELSD.