【摘要】 基于在0.04 mol/L H2SO4介质中,痕量Ti(对KBrO3氧化铍试剂Ⅰ的褪色反应有明显催化作用,且催化褪色程度与溶液中的Ti(量在一定范围内成正比,据此建立了测定痕量钛(的动力学光度法。催化反应对Ti(、铍试剂Ⅰ和溴酸钾而言为一级反应,对H2SO4而言为零级反应,催化反应的表观活化能为55.26 kJ/mol。方法检出限为0.24μg/L,线性范围为0.81~8.0μg/L,用于测定岩石、植物及茶叶中痕量钛,结果与认定值相符。对w(Ti)为10-6水平的试样检测,其RSD(n=6)≤2.8%。更多还原

【Abstract】 Based on the inhibitory effect of trace titanium? on oxidation of beryllon Ⅰ with potassium bromate in the 0.04 mol/L sulphuric acid medium,a new kinetic spectrophotometric method for the determination of trace titanium? was developed.The decrease in the absorbance had a quantitative relationship with the concentration of titanium?.The catalytic reaction was first-order reaction in respect of the concentration of reagents,including Ti?,beryllon Ⅰ and KBrO₃,but it was zero-order reaction as to H₂SO₄.The apparent activation energy of the catalytic reaction was calculated to be 55.26 kJ/mol.The detection limit is 0.24 μg/L and the linear range is 0.81-8.0 μg/L for titanium?.The method has been applied to the determination of trace titanium? in rock,vegetable and tea samples,the results are in agreement with certified values.The relative standard deviation for w（Ti）=10^-6 was ≤2.8%（n=6）.更多还原