钴-乙二胺-亚硝酸盐体系的极谱催化波研究

STUDY ON THE POLAROGRAPHIC CATALYTIC WAVE OF COBALT IN ETHYLENE DIAMINE-NITRITE SOLUTION

本文报道了钴在乙二胺、亚硝酸钠溶液中极谱催化波产生的条件及其在镍盐中杂质钴测定的应用。同时也报道了对这种波形成机理的研究。

In a supporting electrolyte containing 0.04-0.lM ethylene diamine,0.4-l.0M NaNO_(2) and at pH11,we obtained a sensitive polarographic catalytic wave of cobalt.The catalytic wave is in a peak shape withpeak potential between-1.2-1.3V(SCE).The limits of detection ofdc and single-sweep polarography for cobalt are 5×10^(-9)M and 5×10^(-10)M respectively.The method has been applied to the determination of cobalt in nickel salts.It is confirmed that in the compact layer of electrical double layer the associated ion pair[(Co(en)^(3))^(2+).NO_(2)-]+results in the formation of catalytic wave.The overall electrode reaction may be represented as follows:■.