New membrane electrodes based on a functionalized tetraphenylborate covalently bound to the polymeric backbone

In this study new liquid contact polymeric membrane ion-selective electrodes (ISEs) have been realized with the aim of reducing leaching phenomena of active component and so improving the shelf life of the electrode. A new tetraphenylborate ion exchanger functionalized with allylic moieties has been synthesized and linked to a copolymer acrylonitrile–butadiene, alternative to PVC. The linking reaction takes place by radicalic mechanism and is catalysed by dicumyl peroxide. The leaching of the so obtained polymers has been evaluated by spectrophotometric and potentiometric measurements to check the effectiveness of the reaction. In order to test the performances of the new polymeric material, ISEs with and without ionophore have been prepared using the functionalized matrix as well as traditional PVC as polymeric membrane. Analysis of variance was carried out on the detection limit and on the slope of the calibration curve obtained for every kind of electrode, in order to identify the effects of the covalently bound ion exchanger on the lifetime and performance of the sensors.