催化极谱法同时测定核纯八氧化三铀中痕量铅和镉

SIMULTANEOUS DETERMINATION OF TRACE CADMIUM(Ⅱ) AND LEAD(Ⅱ) IN NUCLEAR-PURE U_3O_8 BY CATALYTIC POLAROGRAPHIC METHOD

在１ｍｏｌ／Ｌ硝酸介质中，铀被ＣＬ—５２０９萃淋树脂定量吸附，并与铅、镉等元素分离。收集流出液，加热蒸干后，在酸性（ｐＨ＝２）底液中，铅和镉与碘离子生成络合物吸附于滴汞上，可进行阴极化二次导数极谱法测定。铅、镉的峰电位分别为－０．６２Ｖ、－０．８０Ｖ（相对饱和甘汞电极）。铅、镉浓度在０．０１—１．０μｇ／ｍＬ是线性关系，对于痕量镉（小于０．１ｐｐｍ）的测定可在测定铅的波高之后，再加入一滴四丁基碘化铵乙醇溶液，镉的波高增加３倍，并有线性关系。方法精密度≤±１０％，回收率为９０％－１１０％。

simple, rapid and sensitive method was proposed for simultaneous determination of trace cadmium(Ⅱ) and lead(Ⅱ) in the nuclear-pure U3O8. The quantitative uranyl(UO2+2) was separated with the extractant-containing resin CL-5209. After determination of lead, a drop of tetrabutylammonium iodide was added into the solution, and the sensitivity of cadmium was increased three times. The peak patentials of Ph(Ⅱ) and Cd(Ⅱ) were 0.62V and 0.8V (vs. S. C. E. ) respectively. The height of the adsorption waves was rectilinearly related to the concentrations of Ph(Ⅱ) and Cd(Ⅱ) in the range of 0.01 to 1.0μg/mL. The precisions of the method for determination of Ph(Ⅱ) and Cd(Ⅱ) were ±6% and ±10% respectively, and the recoveries were 90%-110%and 93%-106% respectively.