Construction of Cu۲+-selective electrode and thermodynamic study of the ternary aqueous mixed electrolyte system (CuCl۲, KCl, H۲O) using nanocomposite-based potentiometric sensor

A nanocomposite membrane Cu۲+ ion-selective electrode has been constructed using a new compound ethyl ۱,۲,۳,۴-tetrahydro-۴-(۴-methoxyphenyl)-۶-methyl-۲-oxopyrimidine-۵-carboxylat (ETMOC) as a neutral ionophore. The electrode works properly. It responds to Cu۲+ ion with a sensitivity of ۲۹.۵ ± ۰.۲ mV/decade over the range ۱.۰ × ۱۰−۹ to ۵.۰ × ۱۰−۱M at pH ۳.۰-۸.۰. The limit of detection was ۴.۵ × ۱۰−۱۰ M. It has a response time of < ۶s and can be used for at least ۳ months without any divergence in potentials. The proposed electrode shows fairly good discrimination of Cu۲+ ion from several cations. Then, electrolyte solution system, CuCl۲, KCl, H۲O in the concentration range from dilute to near saturate from the thermodynamic viewpoint was investigated. The thermodynamic investigations were performed based on Pitzer ion-interaction model by processing experimental data of potentiometric. The thermodynamic investigations were successfully performed by the evaluation of potentiometric experimental data.

Keywords:

Activity Coefficient , Pitzer model , Cu۲+-Selective Electrode , Nanocomposite