摘要
山楂果汁颜色较深，如果测定山楂果实中的水溶性有机酸的含量，使用碱滴定法，电位滴定法不宜掌握滴定终点，用活性炭脱色后滴定法，滴定终点则容易掌握。本文用这３种方法进行了对比实验，其结果活性炭脱色后碱滴定法损失率较高，碱滴定法和电位滴定法测定的结果没有显著性差异，均可使用，只要掌握好滴定终点的颜色变化，能得到准确度较高的结果。同时通过实验又得到了１４个山楂品种的有机酸含量。
Since the colour of hawthorn juice is very deep,the use of alkalimetry and potentiometry methods to measure the hydrotorpic organic acids are difficult to master the end points of the titration. If the juice is faded by active carbon the end points of the titra-tions are easy to master.In the paper,all the three methods are compard,and the results show that there are no marked differences among the them. The rate of loss is compratively high if the titration after fading by active carbon id used. As long as the colour change at the end is well mas-tered,accurate results can be obtained.
关键词
山楂
有机酸
电位法
碱滴定
脱色
hawthorn,organic acid,potentiometry,alkali titration, fading
