铜(Ⅱ)-6-苄基氨基嘌呤络合物吸附波的研究及应用

Studies on the Complex Adsorptive Wave of Cu(Ⅱ)6-Benzyl Aminopurine and Its Application

在0．02mol／L六次甲基四胺缓冲溶液中（pH5．5），铜（Ⅱ）-6-苄基氨基嘌呤（6-BA）在KNO3存在下，于-0．50V左右（vs．SCE）产生一尖锐、灵敏的二次导数极谱波，其峰电流与6-BA浓度在3．0×10^-5～1．0×10^-6mol／L范围内呈线性关系，检出限为9．0×10^-7mol／L。与铜（Ⅱ）浓度在1．0×10^-5～3．0×10^-7mol／L范围内呈线性关系；检出限为1．0×10^-7～mol／L。研究了该波的性质及电极反应机理，证明该波为络合吸附波。铜（Ⅱ）与6-BA的组成比为1：1；电子转移数n=2；α=0．58；反应速率常数Ks=1．81／s。方法用于绿豆、大米和玉米样品中铜的测定，结果满意。

In 0.02 mol/L hexamethylene-tetramine buffer solution（ pH 5.5） , a sensitive second derivative polarographic wave of Cu （ Ⅱ） -6-benzyl aminopufine （6-BA） complex appears at - 0.50 V （ vs. SCE）. The peak current is proportional to 6-BA concentration in the range of 3.0×10^-5～1.0×10^-6mol/L, the detection limit is 9.0×10^-7mol/L. The peak courrent is also proportional to Cu（ 11 ） concentration in the range of 1.0×10^-5～3.0×10^-7mol/L, the detection limit is 1.0×10^-7～mol/L. Several electrochemical methods have been used to study the properties of the wave and the reaction mechanism of electrode. It is proved that the wave is a complex adsorptive one. The molar ratio of Cu （ 11 ） to 6-BA is 1 ： 1. The number of electrons transferred （Ⅱ） is 2 and the transfer coefficient （or） is 0.58 and the rate constant of surface electrode reaction （Ks） is 1.81/s. This method has been successfully applied to the determination of Cu（ Ⅱ） in mung bean, rice and maize .