钒试剂引起的氧极谱催化波及其应用

The Polarographic Catalytic Wave of Oxygen Caused by 2-(Phenylamino)-Benzoic Acid and Its Application

本文报道的氧极谱催化波是由具有氧化还原性质的有机分子钒试剂引起的,其电化学过程为,分子氧经单电子极谱还原生成超氧阴离子O_2^-;钒试剂催化了超氧阴离子O_2^-的歧化作用,从而再生出O_2和H_2O_2。基于这个极谱催化波,本文拟定了测定钒试剂含量的方法。以H_2O_2还原波作检测信号,在0.3mol/L NH_4Cl-0.05mol/L NH_3·H_2O-1％Na_2SO_3(pH9.3±0.2)介质中,波高增量与钒试剂浓度在2×10^(-6)mol/L～1×10^(-4)mol/L范围内有线性关系。

The polarographic catalytic wave of oxygen reported in this paper is found to be caused by the organic molecular 2-(phenylamino)-benzoic acid. The electrochemical process of the catalytic wave is as follows. The superoxide anion O_2^- is generated polarographically by one-electron reduction of oxygen. The dismutation of the O_2^- is catalyzed by 2-(phenylamino)-benzoic acid to reproduce O_2 and H_2O_2. Based on the catalytic wave, the method for the determination of 2-(phenylamino)-benzoic acid is developed. Using the reduction wave of H_2O_2 as the measuring signal, the increment of the peak height is linearly proportional to the concentration of 2-(phenylamino)-benzoic acid in the range from 2×10^(-6) mol/L to 1×10^(-4) mol/L in 0.3 mol/L NH_4Cl-0.05 mol / L NH_3 ·H^2O-1% Na_2SO_3(pH 9.3±0.2) buffer.