Cu(Ⅱ)-3,5-diCl-DMPAP-OP 显色反应及其应用研究

Study on the Colour Reaction of Cu(Ⅱ)-3,5-diCl-DMPAP -OP and its Application

研究了在非离子表面活性剂ＯＰ存在下，２－（３，５－二氯－２－吡啶偶氮）－５－二甲氨基苯酚（３，５－ｄｉＣｌ－ＤＭＰＡＰ）与Ｃｕ（Ⅱ）的显色反应。实验表明，在ｐＨ７．５～１０．０的硼砂缓冲介质中，铜（Ⅱ）与试剂形成１∶２的稳定的红色配合物，其表观摩尔吸光系数ε５５８＝９．７×１０４Ｌ·ｍｏｌ－１·ｃｍ－１，铜浓度在０～６．５μｇ／１０ｍＬ范围内符合比尔定律。在柠檬酸三钠和二酮肟的存在下，可直接用于铝合金和纯铝中微量铜的测定，获得满意结果。

The colour reaction of copper with 2-(3,5-dichloro-2-pyridylazo)-5-dimethylamino phenol (3,5-diCl-DMPAP) in the presence of nonionic surfactant OP was studied.It shown that a stable red complex is formed in the medium of Na 2B 4O 7·H 2O buffer solution (pH7.5～10.0).Its molar absouptivity is 9.7×10 4L·mol -1 ·cm -1 at 558nm.Beer′s law is obeyed in the range of 0～6.5 μg/10mL for Cu(Ⅱ).In the presence of Na 3C 6H 5O 7·2H 2O and C 4H 8O 2N 2(dimethylglyoxime),the method od can be applied directly to determine trace Cu in Al alloy and pure Al with satisfactory results without any separation.