两相滴定法测定甜菜碱两性表面活性剂活性物含量研究

两性表面活性剂在酸性条件下呈现阳离子性质,因此可在酸性条件下加入过量的阴离子表面活性剂,再用阳离子表面活性剂海明进行滴定。采用亚甲基蓝-百里香酚蓝混合指示剂测定甜菜碱型两性表面活性剂活性物含量并研究表面活性剂复配时其他复配剂(如非离子表面活性剂、聚合物以及无机盐)对测定结果的影响。实验结果表明该法可以快速测定甜菜碱型两性表面活性剂的活性物含量并且准确度较高,现象比较明显,易于判断滴定终点,一定浓度范围的复配剂及无机盐对测定结果有一定程度的影响。

Study on Determination of Active Matter Content in Betaine Amphoteric Surfactant by Two-phase Titration Method

Under acidic conditions, amphoteric surfactants have the properties of cation, thus we can add excess anion under the acidic conditions and then use cationic surfactant to titrate. In this paper, methylene blue-thymol blue mixed indicator was used to measure the active matter content in betaine amphoteric surfactant, and the impact of complex surfactants and other agent (such as non-ionic surfactant, polymer and inorganic salt ) on the determination result was investigated. The result show that this method can quickly determine the active matter content of betaine amphoteric surfactant,and it has high accuracy. Furthermore, certain concentration range of complex inorganic agents have a certain impact on measurement results.