【摘要】 首次合成了新显色剂２－（５－羧基－１，３，４－三氮唑偶氮）－５－二乙氨基酚（简称ＣＴＺＡＰＮ），研究了它的性质及其与铋显色反应的条件。结果表明：试剂的分子式Ｃ１３Ｈ１６Ｎ６Ｏ３分子量３０４．３２，ｍ．ｐ． ２５２℃，各级酸离解常数为ＰＫａ１＝３．１，ＰＫａ２＝７．５，ＰＫａ＝９．６；在ＰＨ ７的 ＮＨ４Ａｃ介质中，试剂与铋形成紫红色络合物，λｍａｘ为 ５４０ ｎｍ，对比度△λ为 １２０ ｎｍ，络合比Ｂｉ３＋：Ｒ＝１：２，摩尔吸光系数５．１３ ×１０４Ｌ·ｍｏｌ－１·ｃｍ－１，Ｂｉ３＋在０～１．８ ｍｇ／Ｌ范围内遵守比耳定律，在掩蔽剂的作用下，可不经分离直接测定合金样品及合成工业废水中微量铋，结果满意。更多还原

【Abstract】 The synthesis of reagent 2-(5-carboxy-1, 3, 4-triazolylazo)-5-diethylamino phenol (CTZAPN) and the condition of its reaction with Bi3+ are reported. The structure of the reagent are determined by elemental analysis, UV spectromety,IR spectrscopy and 1 HNMR spectroscopy, Its dissociation constants are: pKa13. l, pKa27. 5, pKa39. 6, λmax = 420 nm. The reagent reacts with Bi3+ to form a stable red complex (1: 2) in the presence of NH4 Ac for pH 7. 0. The apparent molar absorptivity is 5. 13 × 104 L. mol-1. cm-1at λmax=540 nm Beer＇ S law is obeyed in the range of 0~l. 8 mg/L. The method has been applied to the direct determination of bismuth in practical samples with satisfactory results.更多还原