Determine the single-sugar content of Carboxymethylchitosan

The assaying of Carboxymethylchitosan is commonly used the acetylacetone methods. However, the market samples always have different substituted degree and deacetylated extent, so the single-sugar content of samples using acetylacetone methods is often largely deviated to the real values. In the article, the result showed that DNS colorimetric method gains the more precise data that are closed to the theoretical content than Elson-Morgan Method. The range of the DNS method is 200∼1800 g (r= 0.999 5) for/9-(+)-Glucosamine hydrochloride at 520 nm. The sensitivity, accuracy and precision of DNS method were high, and the average recollection rate was 100.06%. Therefore, DNS method is suitable for determining reducing sugar in carboxymethylchitosan.