混合微乳液的增敏作用研究──Cd(Ⅱ)-5-Br-PADAP的分光光度测定

Sensitized Reaction of Mixed Microemulsion on the Cadmium with 2 (5 Bromo Pyridylazo) 5 Dethyaminophenol

研究了在Ｏ／Ｗ混合微乳液ＳＤＳ－ＯＰ／ｎ－Ｃ４Ｈ９ＯＨ／ｎ－Ｃ７Ｈ１６／Ｈ２Ｏ介质中，Ｃｄ（Ⅱ）－５－Ｂｒ－ＰＡＤＡＰ的显色反应．结果表明显色反应的灵敏度（ε＝２．４１×１０５Ｌ·ｍｏｌ－１·ｃｍ－１）较单一的ＳＤＳ微乳液（ε＝２．０６×１０５Ｌ·ｍｏｌ－１·ｃｍ－１），单一的ＯＰ微乳液（ε＝２．０×１０５Ｌ·ｍｏｌ－１·ｃｍ－１），混合ＳＤＳ－ＯＰ胶束（ε＝２．０２×１０５Ｌ·ｍｏｌ－１·ｃｍ－１）介质中，具有更好的增敏作用和稳定性，Ｃｄ（Ⅱ）浓度在０～５（ｇ／１０ｍＬ范围内符合比尔定律．方法用于废水和环境水样中微量Ｃｄ（Ⅱ）的测定，结果满意．

The spectrophotometric determination of Cadmium is studied with 2 (5 bromo 2 pyridylazo) 5 dethyaminophenol in the SDS/emulsor OP/n butanol/n heptane/water microemulsion medium. The results show that the maximum absorption wavelength was at 565nm,and the sensitivity in SDS/emulsor OP/n C 5H 11 OH/n C 7H 16 /H 2O mixed microemulsion medium was the highest comparing with that in SDS microemulsion or emulsor OP microemulsion medium. The molar absorption coefficient was 2.41×10 5L·mol -1 ·cm -1 . Beer's law was obeyed in the Cd(Ⅱ) concentration range of 0￣5μg/10mL. The method has been applied to the direct determination of Cd in the practical sample with satisfactory results.