高碘酸盐氧化亚甲蓝动力学光度法测定痕量锇  

Kinetic Spectrophotometric Determination of Trace Osmium by Its Catalytic Effect on the Oxidation of Methlyene Blue

作　　者：李祖碧[1] 曹秋娥[2] 王加林[1] 徐其亨[2] 

机构地区：[1]云南大学成人教育学院,昆明650091 [2]云南大学成人教育学院化学系,昆明650091

出　　处：《分析化学》2000年第3期361-364,共4页Chinese Journal of Analytical Chemistry

摘　　要：以Os（Ⅳ）催化高碘酸盐氧化亚甲蓝（MB）反应为基础提出了测定痕量锇的方法。在90℃加热14min和660nm波长处采用固定时间法测定亚甲蓝吸收的降低，锇浓度在0～3．2μg/L范围呈线性关系，检出限为0．02μg/L，对1．6μg/LOs规测定的RSD为1．56％（n＝11），催化反应对Os（Ⅳ）、MB、KIO4和H2SO4均为一级反应，催化反应的表观活化能为87．72kJ/mol，探讨了反应机理，所提出的方法在蒸馏分离后应用于某些岩矿和冶金产品中锇的测定，结果满意。A method is presented for the detendnation of Os(Ⅳ), based on the catalytic effect of Os(Ⅳ) onthe oxidized reaction of methlyene blue(MB) by periodate. The reaction was monitored spectrophotometrically by measuring the discolor of methytne blue at 660 nm by the fixed time method, at a given time (14 min) and 90℃. A linearrelationship exists in the concentration rangn of 0～ 3. 2 μg/L for Os, and the detection limit is 2.03 ×10-5 mg/L. The relative standard deviation for 1. 6 μg/L osmium is 1 .6% (n = 11). The catalytic reaction is first-order in Os, MB, KIO4and H2SO4, respehvely. The apparent activation energy of catalytic reaction is 87 .72 kJ/mol. The reaction mechanium is discussed. The proposed method has been applied to the determination of osmium in some ores and metallurgical products after a separation of osmium by distillation. The results obtalned proved to be satisfactory.

关 键 词：锇 亚甲蓝 高碘酸盐 动力学光度法 

分 类 号：O657.3[理学—分析化学]