阻抑动力学光度法测定稀土氧化物中痕量镧(Ⅲ)

Inhibitory kinetics spectrophotometric determination of trace La(Ⅲ) in rare earth oxides

阻抑动力学光度法是测定痕量镧(Ⅲ)的新方法.在十六烷基三甲基溴化铵(CT-MAB)存在下,H3PO4介质中痕量镧(Ⅲ)对溴酸钾-氧化考马斯亮蓝的褪色反应具有阻抑作用.通过研究试剂用量、反应温度、反应时间和干扰离子等因素的影响,证明阻抑动力学光度法可以用于稀土氧化物中痕量镧(Ⅲ)的测定,测定结果可靠.

A new inhibitory kinetic spectrophotometric method was developed,which could determine the trace lanthanum（Ⅲ）.In H3PO4 medium,the method was based on inhibitory discoloring effect of Coomassie brilliant blue oxidized by KBrO3 using cetyltrimethyl ammonium bromide（CTAB）as sensitizer.The effect of reagent dose,reaction temperature,reaction time and coexisting ions were discussed.The inhibitory kinetic spectrophotometric method has been applied to the determination of trace lanthanum（Ⅲ） in rare earth oxides with satisfactory results.