Influence of hydronium ions on the distribution of sensitivity of potentiometric PD-sensor on ions in aqueous-organic solutions

Abstract

The influence of Н3О+ ions on the distribution of sensitivity of potentiometric PD-sensor on ions in
aqueous solutions, containing LysHCl (ThiaminCl) and inorganic electrolytes, and also in the reconstituted
milk were investigated. The highest sensitivity of PD-sensors to lysine and thiamine cations in test-solutions
was obtained for perfluorinated sulfonated cation-exchange membrane in K-form. This is achieved by
decrease of concentration of Н3О+ ions in the membrane phase, as well as by decrease of influence of
protolytic reactions at the membrane/ test solution interface on the PD-sensors responses. In this case, the
ion-exchange reactions at the membrane/ test-solution interface have an influence on the PD-sensors
response. Accounting of contribution of Н3О+ ions in response of PD-sensors based on membranes in Kform
leads to increased the sensitivity of PD-sensors to thiamine ions in aqueous solutions and reconstituted
milk.