新显色剂2—（4—安替比林偶氮）—4，5—二羧甲氧基苯甲酸与铋显色反应的研

STUDIES ON COLOUR REACTION OF 2 (4 ANTIPYRINYLAZO) 4,5 DICARBOXYLMETHYL BENZOIC ACID (AADCB)AND BISMUTH

光度分析法测定铋的显色剂较多，￣［１～４］但灵敏度不甚高。作者合成一尚未见报道的试剂，２—（４—安替比林偶氮）—４，５一二羧甲氧基苯甲酸（ＡＡＤＣＢ），能与Ｂｉ￣（３＋）发生高灵敏的显色反应（ε＝２０．８ｘ１０￣４Ｌ／ｍｏｌ．ｃｍ），且表现出较好选择性。

A new antipyrinylazo reagent AADCN was reported as a highly sensitive and selective chro-mo-genic reagent for bismuth in this paper.AADCB reacts with Bi￣(3+) to form a stable 3:1 chelate.Theabsorption maxima of this chelate lies at 692nm with an apparent molar absorptivity of 20.8x10￣4,following the Beer’law in the range Bi 10～20μg/25ml.