title: Chemically modified electrode based on poly[tetra(4-aminophenyl)porphyrin] as a pH sensor.
abstract: A chemically modified platinum electrode with coated poly[tetra(4-aminophenyl)porphyrin] has been used as a potentiometric pH sensor. It gives a linear response over the pH range 1.5-13.7 with a slope of 55 mV/pH (at 20 degrees ). The sensor has fair resistance to erosion of hydrofluoric acid and to interference of a coexisting redox couple. The sensor can be used for pH determination and end-point indication for potentiometric titration of hydrofluoric acid with sodium hydroxide. The a.c. impedance of the polymer membrane has also been studied.
authors.affiliation: Department of Chemistry and Chemical Engineering, Hunan University, Changsha, 410082 People's Republic of China.
authors.forename: R
authors.initials: R
authors.lastname: Yuan
authors.forename: Y Q
authors.initials: YQ
authors.lastname: Chai
authors.forename: G L
authors.initials: GL
authors.lastname: Shen
authors.forename: R Q
authors.initials: RQ
authors.lastname: Yu