维生素C含量的测定实验报告.doc

曹威 5090809047 F0908002 The quantity measurement of ascorbic acid and the comparison of ascorbic acid Introduction Vitamin C is one of the essential vitamin among all vitamin. Vitamin C also ascorbic acid. The name is derived from a- (meaning no) and scurvy, the disease caused by a deficiency of vitamin C. It has the most important function on regulating the metabolism in the human body even in the animal. According to the recently research, it also have the ability to prevent the tumor and blocking the chemical carcinogen.We design this experiment to figure out the relationship between the temperature and the VC content of the nature Fresh Tangerine juice.Through titrate with standard ascorbic acid solution (1mg/ml)，we only find there is relationship between temperature and VC content，but we dont know what it is.We are willing to do in-depth study on this item to make the law clear. Key words : Ascorbic acid, 2,6-Dichloro-phenol-indeophenol (DCPIP),Temperature 1 Preface Vitamin C mainly exists in fresh fruits and vegetables. Among all types of fruits, kiwi contains most vitamin C while lemon and orange also rich in vitamin C. Besides, vitamin C is highly content in chili and also found in other kind of vegetables like tomato, radish. In wild plants, Vitamin C most abundant in a species of roses, which contains 2800mg per 100g. Characteristic of the ascorbic acid Vitamin C is a colorless crystal, insoluble in water and ethanol, heat labile , unstable in the alkaline solution, more stable under dry conditions and susceptible to oxidation after explode to sunlight. The existence of some heavy metals like trace copper, iron cause vitamin C easier decompose due to oxidation, so should avoid contact with alkali and copper when cooking vegetables. Therefore, vitamin C should be stores in dry, dark place at low temperature. In 1928, Arctic anthropologist Vilhjalmur Stefansson proved that fresh meat which is minimally cooked also contains vitamin C