摘要
2-[5-溴-2-吡啶偶氮]-5-二乙氨基酚(简称5-Br-PADAP),能与多种金属离子产生灵敏的显色反应,但将这些物质用于测定镉的报导还不多见,尤其采用非离子表面活性剂曲拉通(Triton X-100)作增溶剂的报导至今未见。本文的作者对镉(Ⅱ)-5-Br-PADAP-曲拉通显色反应进行了详细的研究。在pH为9.0的硼砂缓冲溶液中络合物最大吸收峰为567 nm,表观摩尔吸光系数ε_(567)=1.2×10~5l·mol ^(-1)·cm^(-1),镉含量在0～12.0μg/25ml范围内符合比耳定律,络合物组成比为Cd:R=1:2。拟定了水中微量镉的测定,结果较好。
A new colour reaction of Cd(Ⅱ), based on the formation of a complex of Cd(Ⅱ), has been developed by using 5-Br-PADAP in the buffer solution of di-sodium tetra-borate at pH 9.0 in the presence of triton x-100. The maximum absorption of the complex is at 567nm, and its apparent molar absorptivity is 1.2×10~5 1.mol^(-1).cm^(-1).The results are consistent with Beer's law. This method can be used to measure the cadmium in water accurately.
关键词
镉
显色反应
5-BR-PADAP
cadmium, colour reaction, apparent molar absorptivity, 2-(5-bromo- 2- pyridylazo ) -5 - diethylaminophenol.
