Chondroitin Testing Method Validated

ANAHEIM, Calif.—Analytical Laboratories (www.analytical-lab.com) announced it completed a single laboratory validation (SLV) of a method to quantify chondroitin sulfate (CS) in raw materials and dietary supplements. Quantitative analysis of CS has been challenging due to the wide molecular weight variation of CS polymers, its poor UV absorbance and strongly ionic nature. In addition, any analytical methodology must be able to identify CS versus other glycosaminoglycans (GAGs) in the matrix.

In the method developed by Analytical Laboratories’ David Ji, the CS is first extracted in water, then selectively hydrolyzed by chondroitinase ACII enzyme to form unsaturated disaccharides; the resulting disaccharides are quantified by ion-pairing HPLC with UV detection. SLV work determined the repeatability, accuracy, selectivity and linearity of the method. Development and validation of the method was funded by the National Institutes of Health (NIH) Office of Dietary Supplements (ODS); the SLV manuscript will be submitted to the Journal of AOAC International for publication.

Ji and Mark Roman, Tampa Bay Analytical Research, will then co-direct an AOAC collaborative study, involving 12 international laboratories, on the method. If the results are acceptable, the method will be recommended for adoption by AOAC as an official method.