速差吸光光度法连续测定钴和镍

SUCCESSIVE PHOTOMETRIC DETERMINATION OF COBALT AND NICKEL BASED ON THEIR REACTION RATE DIFFERENCE

基于钴离子和镍离子对过氧化氢氧化对羟基苯基荧光酮反应催化速率的差异,拟定了连续测定钴离子和镍离子的速差动力学吸光光度法,消除了相互干扰,测定钴离子和镍离子的线性范围分别为0～20ng/25ml和0～50ng/25ml,检出限分别为8.11×10^(-13)g·ml^(-1)和6.53×10^(-12)g·ml^(-1),用于混合样中钴离子、镍离子的回收及维生素B_(12)中钴的测定,结果满意。

A new photometric method for the determination of trace Co2+ and Ni2+ based on the difference of their reaction rate is reported in this paper. The method is based on the obvious difference of their catalytic action on the oxidation of p-hydroxy-phenylfluorone by hydrogen peroxide in alkaline medium. A linear relationship holds in the concentration range of 0-20ng Co2+/25ml and 0-50ng Ni2+/25ml, the detection limit is 8. 11×l0-13g ?ml-1 Co2+ and 6. 53×10-12g ?ml-1Ni2+. The proposed method has been applied to the determination of cobalt and nickel with satisfactory results.