偶氮氯瞵Ⅲ自1961年被提出用作分析试剂以来,一直受到人们的重视。在国内,近几年来主要用它进行铀和稀土元素的光度测定。偶氮氯瞵Ⅲ比偶氮肿Ⅲ,能在更强的酸性溶液中与一些金属离子发生颜色反应,灵敏度高,选择性好。例如,采用偶氮氯瞵Ⅲ可以直接测定球墨铸铁中的稀土总量,大量铁采用EDTA掩蔽而无干扰。 Since it was proposed as an analytical reagent in 1961, it has been valued by people. In China, it has been mainly used for photometry of uranium and rare earth elements in recent years. Azocresol III than azo nitrogen Ⅲ, in a more acidic solution with some metal ions color reaction, high sensitivity, good selectivity. For example, the use of arsenic chloride 瞵 Ⅲ can be directly measured ductile iron in the total amount of rare earth, a large number of iron masked with EDTA without interference.