钇(Ⅲ)-3-噻唑偶氮-5-氨基苯酚络合物的极谱络合吸附波研究

Study on polarographic adsorptive wave of Y(Ⅲ)-3-thiazolylazo-5-amino phenol complex

在pH 8.40的NH3-NH4Cl缓冲溶液中,钇与3-噻唑偶氮-5-氨基苯酚络合物有一灵敏的极谱吸附波,其峰电位在-0.67 V(vs. SCE),峰电流与钇的浓度在1×10-7～8×10-4 mol/L之间呈线性关系,检出限为8×10-8 mol/L;经多种电化学方法证明该波为络合物吸附波,其电极过程为不可逆过程,电子转移数为2,此外还试验了多种离子对峰电流的影响,所拟方法已用于茶叶中钇的测定.

In a NH3-NH4Cl buffer solution of pH 8.40, Yttrium（Ⅲ）reacts with 3-Thiazolylazo-5-Aminophenol to form a complex which produces a sensitive polarographic wave at the potential of - 0.67 V （ vs. SCE）. The second-order derivative peak current is linear to the concentration of Yttrium（Ⅲ）, in the range of 1×10^-7 - 8× 10^-4 mol/L, with the detection limit of 8×10^-8 mol/L. Several electrochemical methods were used to study the properties of the wave. It was proved to be an adsorptive wave of the complex of yttrium. The electrode reaction is an irreversible reduction process, and the number of electron transfer is 2. The effects of many ions on the peak current were tested. The proposed method was used to determine the trace yttrium in tea with satisfactory resuits.