近年来我国分析化学工作者对如何提高微量铝显色反应的灵敏度作了许多研究。目前认为,铬天青S是铝的较好显色剂,但灵敏度还不够高(ε=5.9×10~4)。我们采用武汉大学首次合成的间溴偶氮羧—m与铝直接显色,通过一系列条件试验研究得知,试剂的λ max为540nm,络合物的λmax为690nm,⊿λ=150nm,对比度高。显色酸度范围pH2.3～4.0。摩尔吸光系数可达1.1 In recent years, analytical chemists in China on how to improve the sensitivity of trace aluminum color reaction made many studies. At present, chrome azure S is a better developer of aluminum, but the sensitivity is not high enough (ε = 5.9 × 10 ~ 4). We used the first synthesis of m-bromo-azocarboxy-m with aluminum directly developed by Wuhan University. Through a series of experimental conditions, the λ max of the reagent is 540 nm, the λ max of the complex is 690 nm, the λλ is 150 nm, the contrast ratio high. Coloring acidity range of pH2.3 ~ 4.0. Molar absorption coefficient up to 1.1