Studies on potentiometric titrations using simple liquid membrane-based electrodes: Coated wires vs. Carbon pastes

An overview is given on the use of simple potentiometric sensors to monitor titrations based on various principles. Earlier results obtained with polymeric membrane electrodes of the coated-wire type are compared to those taken with carbon paste electrodes. Both the types can be recommended as simple and inexpensive sensors suitable to monitor titrations based on ion-pairing principles. It is expected that an organic solvent present in both the sensors (a membrane plasticizer or pasting liquid) is saturated with an ion-pair formed within such a titration on extraction principles, thus giving selective ion-exchanging electrodes. Although in acid-base titrations and some of determinations based on both oxidation-reduction and precipitation reactions the potential breaks can also be obtained, authors prefer monitoring of them with other suitable sensors