介绍了新试剂６－溴－苯并噻唑重氮氨基偶氮苯（６－Ｂｒ－ＢＤＴＡＡ）与汞（Ⅱ）的显色反应及应用。在非离子表面活性剂Ｔｗｅｎ－８０存在下的弱碱性介质中，试剂与汞形成１∶１的红色络合物，最大吸收波长位于５２４ｎｍ处，表观摩尔吸光系数为１．２４×１０５Ｌ·ｍｏｌ－１·ｃｍ－１。汞量在（０～１．０）μｇ·ｍＬ－１范围内遵守比尔定律，直接应用于废水中微量汞测定，结果满意 The color reaction of 6-bromo-benzothiazyl diazidoazobenzene (6-Br-BDTAA) with mercury (Ⅱ) and its application were introduced. In a weakly basic medium in the presence of non-ionic surfactant Twen-80, the reagent forms a 1: 1 red complex with mercury with a maximum absorption wavelength at 524 nm and an apparent molar absorptivity of 1.24 × 10 5 L · mol-1 · cm-1. Beer’s law was obeyed in the range of (0-1.0) μg · mL-1, which was directly applied to the determination of trace mercury in wastewater. The results were satisfactory