研究了新显色剂 2 -( 1 ,3 ,4 -三氮唑偶氮 ) -5-二乙氨基酚 (简称 TZAPN)与 Bi3+ 的显色反应的条件。结果表明 ,在p H7.0的 NH4Ac缓冲溶液中 ,TZAPN与铋形成稳定的红色配合物 ,λmax=53 0 nm,试剂的 λm ax为 4 3 0 nm,Δλ为 1 0 0 nm,配合比为 1∶ 2 ,其表观摩尔吸光系数为 6.2 9× 1 0 4L· mol- 1 · cm- 1 。Bi3+ 在 0～ 1 .6mg/L范围内服从比耳定律 ,在掩蔽剂作用下 ,可不经分离直接测定合金样品及工业废水中的铋 ,结果满意 The conditions for the color reaction of the new chromogenic reagent 2 - (1,3,4 - triazolylazo) -5 - diethylaminophenol (referred to as TZAPN) with Bi3 + were studied. The results showed that TZAPN forms a stable red complex with bismuth in p H7.0 NH4Ac buffer solution, λmax = 53 0 nm, the λm ax of the reagent is 430 nm, the Δλ is 100 nm, and the mixing ratio is 1: 2, the apparent molar absorptivity is 6.29 × 104L · mol-1 · cm-1. Beer’s law was obeyed in the range of 0-1.6 mg / L for Bi3 +. Under the action of masking agent, the bismuth in the alloy samples and industrial wastewater can be directly measured without separation. The results are satisfactory