Solid-contact lead(II) ion-selective electrodes for potentiometric determination of lead(II) in presence of high concentrations of Na(I), Cu(II), Cd(II), Zn(II), Ca(II) and Mg(II)

Lead and its compounds are a serious threat to the environment. Monitoring of this toxic heavy metal is a driving force for the continuous development of novel lead(II) ionophores to be applied in ion-selective electrodes. In this work a highly selective lead(II) ionophore, namely 25,26,27,28-tetrakis(piperidinylthiocarbonylmethylene)-p-tert-butylcalix[4]arene, was used in solid-contact ion-selective electrodes for determination of Pb(II) at high concentrations of interfering ions, such as Na(I), Cu(II), Cd(II), Zn(II), Mg(II) and Ca(II). The potentiometric response of ionophore-based Pb(II)-ISEs was compared to that of a solid-state crystalline Pb(II)-ISE for Na+, Cu2+, Cd2+ and Zn2+. Determination of lead(II) by ion-selective electrodes was compared to measurements done by atomic absorption spectroscopy. Comparable concentrations of lead were obtained by both techniques, which indicate the possibility to apply such ion-selective electrodes for monitoring of lead in e.g. Zn-Pb mines where the concentration of zinc may be high compared to lead.