测定植物油酸价国家标准方法引入实验教学的改进与实践

Improvement and Practice of Transforming the National Standard Method of Acid Value Determination of Edible Oil into Experimental Teaching

国家标准中采用冷溶剂指示剂滴定法测定油脂酸价,具有实验仪器简单、试剂易得、操作方便的优点。将国家标准方法转化为探究性实验教学内容,有利于激发学生学习兴趣,提高自主学习能力,但是该方法直接应用在实验教学中存在一定的不足之处,因此进行了相应的改进,包括采用常见的常量滴定管代替微量滴定管,降低滴定剂浓度,利用更安全的环己烷作溶剂,通过临近滴定终点前加入去离子水的方式提高滴定终点的稳定性等。在教学实践中采用以学生为主体,以问题为导向的教学模式,培养学生知识整合和综合应用的能力,促进素质型、创新型人才培养。

In the national standard,the cold solvent indicator titration method is adopted to determine the acid value of edible oils,which has the advantages of the simple laboratory instruments,easily got reagents and convenient operation.Introducing national standard method into the zetetic experiment teaching content can stimulate students’interests and improve the ability of autonomous learning,problem solving skills.However,the method was not suitable for direct application so we carried on the corresponding improvement,including using constant burette instead of micro burette,reducing the concentration of titrant,adopting cyclohexane as solvent to improve security,enhancing stability of titration terminal point by adding deionized water near the end of titration.In teaching practice,we adopted the student-centered teaching method and problem-oriented teaching mode to cultivate students’ability of knowledge integration and application.This was conducive to cultivate high qualities and innovative talents.