蛋黄酱、伍斯特酱、酱汁、意粉酱酸度和盐含量

Acidity as acetic acid and salt as sodium chloride in various kinds of food sauces and seasonings are +titrated successively as below: 1) First, acetic acid is titrated with sodium hydroxide. The glass electrode is used to detect the emd point. 2) When the titration of acidity is completed, nitric acid is added to acidify the sample. Chloride ions contained in the sample are titrated with silver nitrate solution. The glass electrode is switched to the silver electrode automatically to detect the end point of the titration.