摘要
研究了显色剂2-(5-Br-2-吡啶偶氮)-5-二甲氨基苯酚(5-Br-DMPAP)吸光光度法测定Zn(Ⅱ)的新方法。在pH值为9.0时,Zn(Ⅱ)与5-Br-DMPAP和非离子表面活性剂乙二醇辛基苯醚(OP)发生高灵敏的显色反应,生成稳定的紫红色配合物。该配合物在556nm处有一最大吸收波长,Zn(Ⅱ)含量在(0～25)μg/25mL范围内符合比耳定律,表观摩尔吸光系数为ε=7.74×104L.mol-1.cm-1,检出限为0.2μg/25mL。方法用于奶粉中微量锌的测定,结果满意。
A new method for the absorptionphotometirc determination of zinc（ Ⅱ ） with the color reagent 2 - （5 - bremo - 2 - pyridylazo） - 5 - dimethylaminophenol was reported. It was found that the zinc（ Ⅱ） ions could react with 5 - Br - DMPAP and OP at pH9.0, to form a violet red complex. The absorption maxima of the complex lied at 556 nm. Beer＇s law was obeyed over the range of 0 - 25 μg/25 mL for zinc （ Ⅱ ）. The apparent molar absorptivity was ε=7.74×10^4 L·mol^-1·cm^-1. The detection limit was found to be 0.2 μg/25 mL. The method was used for the determination of zinc in milk powder with satisfatory results.
出处
《化工时刊》
CAS
2007年第3期28-29,共2页
Chemical Industry Times
