Pb(II)-ion-selective electrodes based on chalcogenide glasses

Novel chalcogenide glasses (ChG) from the GeSe₂-PbSe-PbTe system were investigated as membrane materials in ion-selective electrodes reversible to Pb(II)-ions. Pb(II)-ion-selective electrodes (Pb(II)-ISE) of ‘coated wire’ type were constructed, which consist of standard Ag/AgCl electrodes uniformly coated with a composite mixture of polymer filled with GeSe₂-PbSe-PbTe glassy powder. The basic analytical characteristics of Pb(II)-ISE, such as reproducibility, linear range (L), slope of the electrode function (S), limits of detection (LD), working pH-range and response time (τ₉₅), were studied with respect to the ChG composition. The cross-selectivity in the presence of some interfering ions, which commonly attendant Pb²⁺-ions in analytical media, was investigated. Potential-generating mechanism was suggested explaining sufficiently the observed dependencies.