【摘要】 <正> 测定蔬菜中维生素C的含量一般常用2,6-二氯酚靛酚滴定法或2,4-二硝基苯肼比色法。不过有色的蔬菜浸取液常常妨(石疑)滴定终點的观察;比色法也不能避免浸取液中还原酮还原酸的干摄。最可靠的方法应该是郭与陈二氏的纸分析法。但比色法目前尚在广泛采用,仍有加以研究的必要。Schaffert与Kingsley二氏采用加热100度;使成(?)时间由3小时缩短至10分钟,提高了工作效率。不过所用的氧化剂为活性炭,在裂(?)过程及使用手续上都相当麻烦。用溴作氧化剂也可以得到良好效果,却又必需在通风地方进行以保安全。本文的目的在於试用碘作氧化剂,使氧化手续简便迅速。更多还原

【Abstract】 Iodine was used as an oxidant instead of brimine in the 2,4-dinitro-phenylhydrazine method for the determination of total ascorbic acid content in vegetables. The excess of iodine was removed with a small amount of crystalline thiourea. This process of oxidation was simple, safe and rapid.With this modified method, the ascorbic acid content of 18 vegetables were determined. The ascorbic acid values thus obtained with iodine were sometimes slightly lower than those with bromine, but were higher than those with paper chromatographic method.更多还原