Abstract: The quaternary phosphonium and quaternary arsonium ion-selective electrodes prepared with diesters as active substance and plasticizer were investigated. A PVC membrane electrode based on dioctylphtha.late exhibited a Nernstian response to ω-hydroxy-dodecyltriphenylphosphonium bromide and tetraphenylarsonium chloride. The response mechanism of the electrode was studied by using FTIRspectrometry. The response is caused by the secondary weak force between the positive charge center of quaternary phosphonium (or arsonium) and the electronegative benzene ring in diester.

Key words: Diester electrode, Quaternary phosphonium electrode, Quaternary arsonium electrode