羧甲基淀粉取代度测定方法的改进

Improvement of Determination Method of the Carboxymethyl Starch Substituting Strength

利用铜盐沉淀分离法测定羧甲基淀粉的取代度(0．107),先在pH=6．0-7．0条件下离心分离未反应的硫酸铜和羧甲基铜沉淀物;后在pH=7．5-8．0条件下以PAN作指示剂,用EDTA标准溶液测定CMS的取代度,滴定终点较原方法易观察,灵敏度高,误差小(±0．01％),效果更好。

Making use of Copper salt settlings separation method measurement Carboxymethyl Starch Substituting strength（0. 107） ,first Under the term of the pH =6.0 - 7.0 whizzing non - reactive sediments of copper sulfate and Carboxymethyl Copper; and then under the term of the pH = 7.5 - 8.0 use PAN for indicator, make EDTA standard solution measurement CMS Substituting strength, the original method in terminal point in titration is easy to observe, the sensitivity is higher, the error is smaUer（0.1% ）, the result is better.