摘要
由于妥布霉素固体颗粒在常用滴定溶剂中的溶解度不大,采用常规的卡氏容量法难以快速精确的确定其水含量。本文讨论了两种新方法:第一种是改变滴定溶剂的组成,向其中添加一定量的甲酰胺[甲酰胺∶甲醇(1∶3,V/V)]以提高样品在溶剂中的溶解度;第二种方法是在超声波的作用下把样品溶于纯甲酰胺中,把妥布霉素固体样品转化成液体样品,再通过测定液体样品的水含量间接确定妥布霉素固体的水含量。两种方法都能精确测定妥布霉素的水含量,但后者与前者相比分析速度更快。上述两种方法也适用于其它在卡氏工作溶剂中溶解度不大的氨基糖苷类物质。
As for the poor solubility of tobramycin crystalline product in working medium used in volumetric Karl Fischer titration, two new methods for the water content determination were investigated. The first way was introducing the sample directly in the methanol-based working medium, modified by formamide [formamide ： methanol （1 ： 3, V/V）] in order to increase the solubility; the second way was dissolving them in pure formamide stimulated by ultrasonic and the water content of tobramycin was calculated indirectly by determining the moisture content of formamide solution. Both methods were able to accurately determine the water content in tobramycin and the latter was less time-consuming. These methods were also applicable for the water content determination of other aminoglycosides that were not readily soluble in the working medium.
出处
《中国抗生素杂志》
CAS
CSCD
北大核心
2008年第12期753-755,760,共4页
Chinese Journal of Antibiotics
关键词
卡尔费休法
水含量
妥布霉素
Karl Fischer method
Water content
Tobramycin
