灰分分析法测定羧甲基壳聚糖羧甲基取代度的改进

本文改进了用于测定羧甲基壳聚糖羧甲基取代度的灰分分析法．沉淀样品清洗直至用硝酸银溶液滴定无氯离子为止，然后灼烧成灰，再将之分散于10ml 10．1mol／L H2SO4中，用0．1mol/L NaOH标准溶液滴定，中和过量的硫酸．实验数据及计算结果表明改进的灰分分析法简单、快捷，且精确度与元素分析相当。

Improvement of the Ashing Method to Determine the Degree of Carboxymethyl Substitution of Carboxymethyl Chitosan

In the paper, an ashing method was improved to characterize the degree of carboxymethyl substitution of carboxymethyl chitosan. The deposit sample was not washed till no chloric anion was titrated by silver nitrate solution. Then the sample was burned to become ash and dispersed in 10 ml 0.1 mol/L H2SO4. The excess H2SO4 was titrated by 0.1 mol/L NaOH standard solution. The experimental data and statistical results show that the modificative ashng method is simple, shortcut, whose precision is more dose to that of elemental analysis.