催化动力学分析法测定粗硒粉中微量碲的研究

Determination of Micro Amount of Tellurium(Ⅳ) in Crude Selenium Sample by Kinetic-Specatrophotometry

提出基于Te(Ⅳ)催化S2-还原亚甲基蓝褪色反应,建立了新的测定微量碲的动力学分析方法。研究了催化反应条件,并测定了催化反应的表观活化能为68·94kJ·mol-1,反应速率常数为1·63×10-2s-1。Te(Ⅳ)浓度在20～220ng·mL-1范围内服从比尔定律,回归曲线的线性方程为y=0·0038x+0·2191,相关系数r=0·9995,方法的检出限为3·04ng·mL-1。应用于粗硒粉中微量碲的测定,相对标准偏差为3·1%(n=7),加标回收率为98·4%～100·4%。

A new indicator reaction based on the interaction of sodium sulfide reducing properties with methylene blue in cetyltrimethylammonium bromide pH 3.8 acetic acid buffer solution.was put forward to determine micro amount of tellurium.The effect of concentration of reaction substances,acidity,interfering ions etc.on the analytical results was studied.The apparent activation energy is 68.94 kJ·mol^-1 and the constant of reaction rate is 1.63×10^-2 s^-1.Beer＇s law is obeyed for tellurium in the range of 20-220 ng·mL^-1.The regression equation is y=0.003 8x＋0.219 1 and the correlation coefficient is r=0.999 5.The limit of detection for Te is 3.04 ng·mL-1.The method was applied to the determination of Te in crude selenium sample,and the relative standard deviation is 3.1%（n=7）.The recovery was between 98.4% and 100.4%.