SELECTIVE ELECTRODE FOR SILVER BASED ON POLYMER MEMBRANES CONTAINING EXOCYCLIC CHALCOGEN ATOMS CALIX[4] ARENE AND CROWN ETHER

Four novel exocyclic sulfur and selenium ligands based on calix[4]arenes and crown ethers have been tested as ionophore in Ag+ ion-selective PVC membrane electrodes. All electrodes exhibited good linear responses with one giving a response of 56.0 mV/decade in the Ag+ ion activity range 10-5–10-2 M and show fairly good discriminating ability towards Ag+ ion in comparison to some alkali, alkaline earth, transition and heavy metal ions. The electrodes based on sulfur exocyclic ligands exhibited higher sensitivity than that of selenium analogs. The membrane electrodes based on chalcogen atoms calix[4]arene and crown ether are suitable for use with aqueous solutions at pH > 2.