【摘要】 在HAc介质中,非离子表面活性剂Tween-80存在下,痕量镱(Ⅲ) 对溴酸钾氧化伊文思蓝(EB)的反应具有阻抑作用,据此建立了阻抑动力学光度法测定痕量镱(Ⅲ) 的新方法。探讨了吸收光谱、试剂用量、干扰离子等因素的影响,测定了反应动力学参数。在最佳实验条件下,方法线性范围为4～120μg/L,检出限为3.36×10-7 g/L。阻抑反应为动力学一级反应,表观活化能为101.04kJ/mol,反应速率常数为2.30×10-3/s。反应在表面活性剂Tween-80存在下,其灵敏度提高3倍。方法已应用于氧化钕中镱的测定,测定结果与原子吸收光谱法相一致,相对标准偏差小于2.7%,试样加标回收率为99%～101%。更多还原

【Abstract】 In HAc medium and with non-ionic surfactant of Tween-80 as sensitizer,ytterbium can inhibit the discoloration of evans blue(EB) by KBrO3.Therefore,a new inhibitory kinetic spectrophotometric method for the determination of trace ytterbium was studied.The effects of these factors such as absorption spectra,acidity,concentrations of reagent,influence of coexisting ions on the reaction were discussed and the kinetic parameters were tested.Under the optimum conditions,the linear range was 4-120 μg/L.The detection limit was 3.36×10-7g/L.The inhibitory reaction was the first order reaction and the apparent activation energy of the inhibitory reaction was 101.04 kJ/mol,and the reaction rate constant was 2.30×10-3/s.The sensitivity was increased by 2 times with the existence of surfactant Tween-80.The method was successfully applied to the determination of ytterbium in neodymium oxide,with the relative standard deviation of less than 2.7% and the recovery of 99%-101%.更多还原