In alkaline medium, 8-aminoquinoline-5-azo-p-benzoic acid (AQBA) could react with Au(III) to form a blue complex (3 ! 1), which had maximum absorption wavelength at 610 nm. In the presence of CTMAB, the derivative absorbance increased significantly. One injection of sample could generate a response curve with one peak and one valley. Both two knee points (A1 and A2) could be used for quantitative analysis. If △A = A2-A1 was adopted, the sensitivity could be greatly improved, which was 1. 8 times that of common method. The results showed that Beer's law was obeyed for Au(III) in the range of 0. 04-2.6μg/mL. The hydrolysis products of Fe3+ , Cu2+ , Ni2+ , Hg2+ and Mn2+ could adsorb Au, resulting in interference, which could be eliminated by adding proper amount of EDTA and NaF as masking reagent. The proposed method was applied to the determination of gold in electrolytic anode mud, and the results were consistent with that of the atomic absorption spec-trometry.%在碱性介质中,8-氨基喹啉-5-偶氮-对苯甲酸(AQBA)与Au(Ⅲ)显色络合形成3∶1的蓝色螯合物,该螯合物最大吸收波长为610 nm,在十六烷基三甲基溴化胺(CTMAB)存在的条件下,导数吸光度值明显增加,一次进样产生一峰一谷响应曲线,依据(A1、A2)两个拐点均可用于定量分析.若采用△A=A2 -A1进行分析,灵敏度得到大幅度提高,为普通法的1.8倍.试验表明,Au(Ⅲ)的含量在0.04～2.6 μg/mL范围内遵守比尔定律；Fe3+、Cu2+、Ni2+、Hg2+、Mn2+等离子形成水解产物对Au有吸附作用而产生干扰,可加入适量EDTA和NaF掩蔽剂加以消除.建立的分析技术应用于电解阳极泥中金的测定,结果同原子吸收光谱法的测定结果相一致.
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