Chondroitin disaccharide Δdi-4S sodium salt may be used as a substrate for the identification and characterization of enzymes such as Clostridium perfringens unsaturated glucuronyl hydrolase. Another potential application of Chondroitin disaccharide Δdi-4S sodium salt is that it can potentially be used a reference compound in the analysis of chondroitin disaccharide sulfates.