All Solid State Hydrogen Ion Selective Electrode Based on a Tribenzylamine Neutral Carrier in a Poly(vinyl chloride) Membrane with a Poly(aniline) Solid Contact

Abstract

Hydrogen ion selective solid contact electrode based on tribenzylamine have shown the best Nernstian slope, selectivity and the widest response range in Tris buffered pH sample solutions. Their linear dynamic range was pH 2.48–11.21 and Nernstian slope showed 55.1 mV/pH (at 20±0.2 °C). When it was directly applied to human whole blood (in pH range 6.0–8.5), we could get the same satisfying results. This electrode continuously contacted Tris 7.47 buffered solutions, human whole blood and hydrofluoric acid solutions for one month without any loss of performance. Especially, hydrofluoric acid did not influence the surface of this electrode, thus this electrode was maintained without showing any changes in potentials after used in hydrofluoric acid solution. The standard deviation in the e.m.f. differences determined was 1.0 mV (N=10) at Tris buffer solution of pH 6.5 and 0.5 mV at Tris buffer solution of pH 8.5. The 90 % response time of the electrodes obtained by injection of hydrochloric acid into Tris buffer sample solution was less than 8 s.