摘要
在微酸性介质中痕量Ｖ（Ⅴ）对重铬酸钾氧化偶氮胂Ⅲ褪色的反应有显著的催化作用，催化反应的表观活化能为２１７２ｋＪ·ｍｏｌ－１。据此建立了测定痕量钒的催化动力学分析法。线性测定范围为００２～０２０μｇ·ｍｌ－１，方法检出限为００２μｇ·ｍｌ－１Ｖ。本法重现性较好，用于测定人发、马铃薯、茶叶和废水中钒的含量，结果满意。
The kinetic method for the determination of trace vanadium was established based on its catalytic effect on the colour fading reaction of arsenazo Ⅲ oxidized by potassium dichromate. The optimized conditions for determination are: c K 2Cr 2O 7 =3.0×10 -5 mol·L -1 , c Arsenazo Ⅲ =3.0×10 -5 mol·L -1 at 90℃. The calibration graph is linear for 0.02～0.2 μg·ml -1 , and the detection limit is 0.02 μg·ml -1 V. The active energy of catalytic reaction is 21.72 kJ·mol -1 . Most foreign ions do not interfere with the determination of vanadium except for Fe(Ⅱ), Co(Ⅱ), Cu(Ⅱ) and Mn(Ⅱ). The vanadium contents in hair, tea, potato and wastewater were determined and the results are satisfactory.
出处
《稀有金属》
EI
CAS
CSCD
北大核心
1998年第5期358-360,共3页
Chinese Journal of Rare Metals
基金
山东省自然科学基金
关键词
光度法
钒
催化动力学
环境样品
Vanadium, Colour fading, Arsenazo Ⅲ, Kinetic spectrophotometry, Determination
