[Study on quantitative assay of chondroitin sulfate with a spectrophotometric method of azure A].

A simple, accurate and rapid spectrophotmeric method was proposed for the determination of chondroitin sulfate. The method was based on the absorbances of AA-CS complex at 625 nm being in proportion to the chondroitin sulfate concentrations. The linear range was 0-30 micrograms.mL-1 (R = 0.999), and the recovery range was 97.4%-103.8%. The quantities of chondroitin sulfate in different sample were determined in this way.