Sn(ІІ)-ion-selective electrodes based on chalcogenide glasses for water media analyzes

Sn(ІІ)-ion-selective electrodes (Sn(II)-ISEs) based on chalcogenide glasses (ChGs) from the GeSe2–Sb2Se3–SnSe system were created. All-solid-state Sn(II)-ISEs of “coated-wire” type were designed, which consist of inner Ag/AgCl reference electrodes uniformly coated with composite mixtures of binding polymer and GeSe2–Sb2Se3–SnSe glassy powder. Sn(II)-ISEs were tested in aqua solutions of the potential-determining ions with respect to their basic analytical characteristics: stability, linear range (L, mol l−1) and slope (S, mV dec−1) of the electrode function, working pH-range, limits of detection (LD, mol l−1), response time (τ95, s) and selectivity coefficients (Ki,jpot) in the presence of ions, which commonly accompany Sn2+-ions in the analytical media. Potential-generation mechanism, taking place on the membrane/analyzed solution interface, was suggested to explain the peculiarities in the analytical performance of the Sn(II)-ISEs.