title: PbO2-based graphite-epoxy electrode for potentiometric determination of acids and bases in aqueous and aqueous-ethanolic media.
abstract: The construction and analytical evaluation of a PbO2-based graphite-epoxy electrode sensitive to H3O+, based on incorporation of lead(IV) oxide in a graphite-epoxy matrix, are described. The data obtained from a variety of acid-base titrations in aqueous and aqueous-ethanolic media were compared with those obtained by use of a glass electrode under the same conditions. The proposed electrode provides a linear response in the pH range from 1 to 11 with a slope of -58.7+/-0.3 mV pH(-1) and -60.8+/-0.2 mV pH(-1) in aqueous and ethanolic media, respectively. The response time was less than 15 s and the lifetime of the electrode was at least eight months (ca. 5000 determinations) and its performance is good in pH determination and end-point detection in potentiometric acid-base titrations in both aqueous and aqueous-ethanolic media.
authors.affiliation: Departamento de Química, Universidade Federal de São Carlos, SP, Brazil.
authors.forename: M F
authors.initials: MF
authors.lastname: Teixeira
authors.forename: L A
authors.initials: LA
authors.lastname: Ramos
authors.forename: O
authors.initials: O
authors.lastname: Fatibello-Filho
authors.forename: E T
authors.initials: ET
authors.lastname: Cavalheiro