阻抑动力学光度法测定痕量铈

Determination of Trace Amount of Cerium by Inhibitory Discoloring Kinetic Spectrophotometry

基于痕量铈 (Ⅳ )在中性介质中阻抑过氧化氢氧化甲基紫的褪色反应 ,建立了阻抑动力学光度法测定痕量铈的新方法。研究了该方法的适宜条件 ,在波长 64 0nm处 ,铈 (Ⅳ )的质量浓度在 8× 10 - 4～ 4.4× 10 - 3μg·ml- 1 范围内与阻抑反应速率呈良好的线性关系 ,方法检出限达到0 .0 5 μg·L- 1 。该法用于人发和食品中铈含量的测定 ,效果满意。

A new inhibitory discoloring kinetic spectrophotometric method for the determination of trace Ce(Ⅳ) was studied. The method was based on inhibitory discoloring effect of methyl violet oxidized by hydrogen peroxide in neutral medium. The optimum condition was investigated in detail. The linear range of the method is 8×10 -4 ～4.4×10 -3 μg·ml -1 . The detection limit is 0.05 μg·L -1 . The method is applied to the determination of the cerium in hair and rice with satisfactory results.