Chemically modified electrode based on poly[tetra(4-aminophenyl)porphyrin] as a pH sensor.
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.
Yuan
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R
Department of Chemistry and Chemical Engineering, Hunan University, Changsha, 410082 People's Republic of China.
Chai
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YQ
Shen
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GL
Yu
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