Chondroitin Sulfate: A Critical Review of Generic and Specific Problems in Its Characterization and Determination-An Exemplar of a Material with an Unknown or Variable Composition (UVCB).

This review discusses the criteria for the selection of appropriate reference samples of chondroitin sulfate (CS) and the properties and specific problems of analytical methods for CS, namely titration with cetylpyridinium chloride; various separations; and UV-Vis, NMR, MS, and IR spectroscopies. Suggestions are put forward with regard to acceptable protocols for manufactures' and for official/referee analysts for the analysis of CS in products.