甲基橙——靛红指示剂测定壳聚糖脱乙酰度

INDICATOR OF DEGREE OF DEACETYLATION OF CHITOSAN BY HELIANTHINE-ISATIN MIXED INDICATOR

研究利用甲基橙—靛红指示剂测定低脱乙酰度壳聚糖方法,通过与电导测定法测定结果进行比较,优选出最佳配比。并对不同脱乙酰度壳聚糖样品进行测定。结果表明,甲基橙—靛红(2:1)混合指示剂指示终点准确,变色明显,稳定性好,可以作为测定不同脱乙酰度壳聚糖样品的通用指示剂。

Helianthine - isatin indicator was used in determination of low degree of deacetylation of chitosan. Compared the results of the determination degree of deacetylation with conductometric titration, the optimumratio was obtained. Furthermore, this method was also used in determining the different degree of deacetylation chitosan. The results show that the methyl orange - isatin （2：1） mixed indicator is accurate, having clear color change and good stability. The Helianthine - isatin （2：1） mixed indicator is likely to become common indicator of determining different degree of deacetylation of chitosan.