Exploring the Value of GPC/SEC in Polysaccharide Characterization

Abstract

This article examines the information that can be generated using the latest GPC/SEC technology, which brings the sensitivity needed to differentiate similar polysaccharide samples, and the complementary application of flow injection polymer analysis (FIPA), which facilitates application of GPC/ SEC in the manufacturing environment.

Examples of polysaccharides, widely used as food additives and in certain medical applications, include derivatives of cellulose and starch, such as hydroxymethyl cellulose and maltodextrin, respectively; dextrans; and a group of materials increasingly referred to as renewable polymers: xanthan gum, hyaluronic acid, alginates and gum arabic. Polysaccharides occur naturally and are produced by extraction from a plant or animal-based feedstock, rather than being synthesized in polymerization reactions. Such feedstocks have inherent variability, making it difficult to ensure consistent product quality.

The performance, and in some cases the safety, of polysaccharide-based products depends on their molecular weight (MW), MW distribution and structure. If the MW of the polysaccharide is too high, then the final product may be too brittle and/or firm, while a low MW may result in a far weaklier structured product and other behavioral abnormalities. Furthermore, at low MW, polysaccharides tend to be linear, but as MW increases, so does the likelihood that the molecule will branch. Branching also directly influences performance in a finished product, so controlling both properties is crucial to ensure a safe and efficacious product that behaves as required.

Gel permeation/size exclusion chromatography (GPC/SEC) is used routinely to study the MW and structural characteristics of macromolecules and is useful for polysaccharide characterization. This article examines the information that can be generated using the latest GPC/SEC technology, which brings the sensitivity needed to differentiate similar polysaccharide samples, and the complementary application of flow injection polymer analysis (FIPA), which facilitates application of GPC/ SEC in the manufacturing environment.