MF-4SC Membranes Modified by Polyaniline for Potentiometric Determination of Saccharin and Sodium Ions in Aqueous Solutions

― MF-4SC membranes have been modified by polyaniline (PANI) with the oxidative polymerization method. The influence of the method of obtaining hybrid membranes and the content of PANI in them on the value of IEC, water uptake, and transport properties have been investigated. The characteristics of DP‑sensors (DP is Donnan potential) based on the obtained membranes in aqueous solutions containing saccharin and sodium ions at pH < 7 have been established. It is found that appearance of additional sorption centers in the form of amino groups and fragments with π-π conjugation when introducing PANI to membranes promotes the increase in the sensitivity of DP-sensors to saccharin ions. The use of MF-4SC/PANI membranes obtained by various methods makes it possible to reduce the correlation between the cross-sensitive DP-sensors responses and provides high accuracy of the simultaneous determination of saccharin and sodium ions in aqueous solutions.