RESUMEN
A new all-solid state electrode modified with poly ( o-aminophenol-co-o-phenylenediamine ) film was prepared by cyclic voltammetry.The electrochemical response of the electrode to various solutions in the available acidity range of 1.00 × 10-12-10.0 mol/L was studied by cyclic voltammetry.The results showed that the reduction peak potentials and the available acidity of solution showed good linear relationship in 3 stages of 1.00×10-10-0.10 mol/L, 0.10-2.00 mol/L and 2.00-10.0 mol/L respectively, and the regression equations were Epc=0.0456lgC(H+)-0.295, Epc=0.0803c(H+)-0.309, and Epc=0.0278c(H+)-0.188, respectively.There were similar responses in the solutions of H2 SO4 , HNO3 and HClO4 in the concentration range of 1.00-8.00 mol/L.The preparation method of electrode was simple, and the determination range of available acidity was as wide as 1.0 ×10-10-10.0 mol/L, which laid the foundation for the development of solid-state electrochemical sensors for determination of acidity of high acidity solution.