胶束介质在速差动力学分析中的应用: 钴、镍的同时测定

研究溴化十六烷基三甲铵表面活性剂对钴(Ⅱ)、镍(Ⅱ)与二甲酚橙配位反应的影响, 测定了反应级数和表观活化能。由于胶束介质的存在, 钴(Ⅱ)、镍(Ⅱ)三元配合物的灵敏度比二元配合物分别提高了4.4和8.6倍, 并扩大了两组分的速率差别, 改善了反应的选择性。基于两组分反应速率的差别, 采用对数外推法计算机处理数据, 建立了速差动力学同时测定钴(Ⅱ)、镍(Ⅱ)的新方法。应用于钴精矿等几种实际样品中钴、镍的同时测定获得了满意结果, 其相对误差和标准偏差分别在4%和3%以内。

The application of micellar media in rate differential kinetics analysis: Simultaneous determination of cobalt and nickel

The effect of micellar media (cetyltrimethylammonium bromide) for complex formation reaction of cobalt and nickel ions with xylenol orange (XO) has been investigated. The order of reaction and the apparent activation energy have been determined. The sensitivity of ternary complex of cobalt(Ⅱ) and nickel(Ⅱ) are 4.4 and 8.6 times bigger than binary complex. In the meantime, the difference of the reaction rate of two complex was increased and the selectivity of reaction was improved obviously. A new analytical method hased on the reaction rate difference of two ternary complex, for simultaneous determination of cobalt(Ⅱ) and nickel(Ⅱ) was developed, the logarithmic extrapolation method with computer was used to calculate. This method has been applied to simultaneous determination of cobalt and nickel in samples with satisfactory results. The relative error for determinations of two components was within 4% and the relative standard deviation was within 3%.