胶体滴定法测羧甲基壳聚糖的取代度

The Measurement on Degree of Substitution of Carboxymethyl Chitosan by Colloidal Titration

探讨影响羧甲基取代度的新方法-胶体滴定法的影响因素。采用聚乙烯醇硫酸钾(PVSK)和聚二丙烯二甲基氯化铵(PDMDAAC)为聚阴离子和聚阳离子试剂。结果表明,胶体滴定法测定羧甲基取代度受到pH值、羧甲基壳聚糖的浓度、以及滴定速度的影响。最终得到胶体滴定法测定羧甲基壳聚糖羧甲基取代度的最佳条件:测定时pH值一定要在能使CMC充分解离成离子的pH范围内进行,滴定速度以0.02ml/s左右为宜,CMC的测定浓度在0.01%～0.02%(w)左右。

To study the factors influencing colloidal titration on measuring degree of substitution（DS）of carboxymethyl chitosan（CMC）,we used poly（vinyl alcohol potassium sulfate）（PVSK）and poly（dimethyl diallylammonium chloride）（PDMDAAC）in the colloidal titration.The factors such as pH value,the concentration of CMC,titration velocity,etc.influencing DS were respectively investigated.We found that the pH value should be tested under the situation in which CMC can be completely ionized.Titration velocity should be 0.02 ml/s or so and the concentration of CMC solution should be within the range of 0.01%-0.02%（w）.