氯酸钾存在下铍-铝试剂体系的极谱波研究及应用  

Polarographic Behavior of Beryllium-Aluminon Complex in the Presence of Chlorate and Determination of Beryllium

作　　者：李建平[1] 谢拥军 魏小平 

机构地区：[1]桂林工学院应用化学系,桂林541004 [2]广西地质环境监测总站,桂林541004

出　　处：《分析化学》1999年第12期1416-1419,共4页Chinese Journal of Analytical Chemistry

摘　　要：研究了在氯酸钾存在下铍-铝试剂体系的极谱波行为及应用.在pH7.5的Clark-Lubs缓冲溶液中,铍-铝试剂络合物于-0.77V可产生灵敏的极谱波,加入氯酸钾后极谱波移至-0.73V,波高增大了3倍,导数波高与Be^(2+)浓度在0.005～0.2mg/L范围内呈线性关系,检测限3.5×10^(-3)mg/L.研究了极谱波性质及电极反应机理,证明该极谐波为络合吸附催化波.铍与铝试剂形成配位比1:2的络合物,络合物中的铝试剂在电极上还原,电还原中间产物被氧化回原价态形成催化循环,波高增大.In pH 7.5 Clark-Lubs buffer solution, the complex of Be(Ⅱ)-aluminon can produce a sensitive polarographic wave at - 0.77 V (vs. SCE). When potassium chlorate was added, the wave height increased about 3 times and the peak potential moved to - 0.73 V. The derivative wave height is linear with the concentration of beryllium in the range of 0.005-0.2 mg/L, the detection limit is 3.5μg/L. The adsorption and catalysis character of the wave was proved by the experiments. The mechanismof the electrode process was proposed. The composition of beryllium-aluminon complex was found to be 1:2. Aluminon in the complex was reduced and its product was then oxidized by potassium chlorate to reproduce the original ligand. A catalytic cycle was formed and the sensitivity was increseased obviously. The method has been applied to the determination of Be in the rock and soil samples.

关 键 词：络合吸附催化波 铍-铝试剂 极谱波 氯酸钾 

分 类 号：O614.21[理学—无机化学] O657.14[理学—化学]