Abstract This paper introduces a scalable analytical chemistry teaching experiment:coordination titration method for the determination of calcium ion in rape. This experiment involves the knowledge and operation of the coordination titration method in the field of analytical chemistry, which is helpful for students' theoretical knowledge learning and experimental skills mastering. It is recommended as a basic experiment for freshmen. Because calcium ions participate in the metabolic process of rape, it plays a key role in the growth and development of rape. Therefore, it is necessary to accurately determine the calcium content in rape to facilitate timely detection of problems, so the experiment itself has very important application value. In this experiment, under the condition of pH=12~13, direct titration was carried out with EDTA standard solution. Calcium carboxylic acid was used as indicator, the interference of iron and manganese ions was eliminated by triethanolamine, and the interference of magnesium ion and phosphate ion was inhibited by dextrin. Comparing this method with the national standard method (flame atomic absorption method), there is no significant difference between the data obtained by the two methods. It is reliable and accurate to determine the calcium ion content in rape by this method.
LUO Jing-Rui, WANG Jin-Ling, FANG Ming-Ji, LIU Lin-Lin, WANG Li-Xia. Determination of Calcium Ion in Rape[J]. Chinese Journal of Chemical Education, 2020, 41(16): 44-48.
