两种冰醋酸涂剂稳定性的探讨

Study of Glacial Acetic Acid Paint Prescriptions

目的探讨冰醋酸涂剂在不同溶媒中的稳定性,为修订处方提供参考。方法采用酸碱滴定法测定不同储存条件下冰醋酸在75%乙醇和水两种溶媒中的含量变化;采用气相色谱法考察乙酸乙酯含量。结果以75%乙醇为溶媒的冰醋酸涂剂在不同温度下储存,含量随时间延长而逐步降低,温度越高,下降越快,并产生乙酸乙酯;以水为溶媒的冰醋酸涂剂,醋酸含量无明显变化。结论以75%乙醇为溶媒的冰醋酸涂剂欠稳定,以水为溶媒的冰醋酸涂剂可以长期常温下储存。

Objective To study the stability of glacial acetic acid in different solvents and to provide reference for the revision of glacial acetic acid paint prescriptions. Methods Acid-base titration method was used to determine actic acid in different solvents and under different storage conditions. GC method was used to determine ethyl acetate. Results During storage,the content of acetic acid paint decreased with the time. The higher the temperature,the faster the decrease and the more ethyl acete. With water as the solvent,acetic acid showed no significant change long-term room temperature storage. Conclusion The glacial acetic acid paint is unstable,so 75% ethanol should be replaced by water as the solvent.