钢样中微量铜的分光光度法测定

在pH 6.5的Na2HPO4-KH2PO4缓冲介质中及阳离子表面活性剂溴化十六烷基三甲胺（Cetyltrimethyl ammonium Bromide,CTMAB）存在下,研究了2,3,7-三羟基-9-（3,4-二羟基）苯基荧光酮（3,4-DHPF）与Cu2＋之间的显色反应,以此建立了分光光度法测定铜的新方法.结果表明：Cu^2＋和3,4-DHPF形成2∶1的红色络合物,其最大吸收波长为558 nm,测定Cu^2＋表观摩尔吸光系数为1.28×10^5L.mol^-1.cm^-1,Cu2＋含量在0-1.2μg/5 mL范围内符合比尔定律.采用拟定分析方法用于钢样中微量铜的测定,结果满意.

Spectrophotometric Determination of Trace Copper in Steel Sample

At the existence of cationic surfactant cetyltrimethyl ammonium bromide（CTMAB）, the color reaction of 3,4-DHPF and Cu^2＋ was studied; and a new spectrophotometric determination of trace copper had been build in the buffer solution （pH 6.5 of Na2 HPO4-KH2PO4 ）. The results showed that the molar ratio between Cu^2＋ and 3,4-DHPF in the red micelle is 2 ： 1; and the maximum absorption wavelength of 3,4-DHPF- Cu^2＋-CTMAB complex was 558nm; and the apparent molar absorptivity was 1.28 ×10^5 L· mol^-1 · cm^-1） and Beer＇s law was obeyed when concentration of Cu2＋ was in the range of 0-1.20 μg/5 mL. The apreparation method has been applied to deterimining trace Cu^2＋ in the steel sample satisfactorily.