新显色剂2,6-二溴-4-羧基苯偶氮重氮氨基苯偶氮苯与汞的显色反应研究和应用

Study on Color Reaction of Hg(Ⅱ) with New Reagent 2,6 Dibromo 4 carboxylbendiazoaminoa zobenzene and Its Application

研究了新合成显色剂 2 ,6 -二溴 - 4 -羧基苯偶氮重氮氨基苯偶氮苯( BCADAB)的理化性质及其与汞 ( )的灵敏显色反应。在有 Triton X- 1 0 0存在的 p H1 1 .2的氨水 -氯化铵缓冲液中 ,汞 ( )与显色剂生成 1∶ 2的稳定橙红色配合物 ,其最大吸收波长为 52 0 nm ,表观摩尔吸光系数为 1 .1 7× 1 0 5L· mol-1· cm-1。 Hg( )在 0～ 35μg/2 5m L范围内符合比耳定律。本法已用于环境水样中微量汞的测定。

The physical and chemical properties of the newly synthesized reagent 2,6 dibromo 4 carboxylbendiazoaminoazobenze (BCADAB) and its highly sensitive color reaction with Hg(Ⅱ) have been studied. In the presence of Triton X 100, Hg(Ⅱ) reacts with BCADAB to form a stable orangered complex with molar ratio of 1∶2 in ammonia buffer solution (pH 11.2). The apparent molar absorptivity is 1.17×10 5 L·mol -1 ·cm -1 at the maximum absorption wavelength of 520 nm . Beer's law is obeyed in the concentration range of 0～35 μg Hg(Ⅱ) in 25 mL solution The method has been applied to the determination of trace amount of mercury in waster water.