A SO2-selective electrode based on a Zn-porphyrin for wine analysis.
Anal Chim Acta
; 787: 57-63, 2013 Jul 17.
Article
en En
| MEDLINE
| ID: mdl-23830421
ABSTRACT
This work describes the assessment of a SO2-selective electrode based on the use of the neutral carrier 5,10,15,20-tetraphenyl(porphyrinate)zinc(II) in a PVC membrane plasticized with 2-nitrophenyl phenyl ether. After being conditioned in 2 mol L(-1) diethylamine solution for 24 h, the electrode exhibited selective anionic response toward the analyte in a concentration interval of more than four decades, with an slope of -59.5 mV dec(-1), a practical detection limit of 3.7×10(-6) mol L(-1) and a low limit of linear range of 7.2×10(-6) mol L(-1). The response mechanism is based on the displacement of the diethylaminemetalloporphyrin complex equilibrium within membrane bulk, inducing a variation in the cationic-sites to ionophore ratio. In turn, free hydroxyl ions are complexed by the displaced ionophore in a ratio 11 and translated as single negative charge nernstian response. Finally, the selectivity of the electrode is evaluated in view of its application to wine analysis. Results had high accuracy and precision when compared with a reference method.
Palabras clave
Texto completo:
1
Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Dióxido de Azufre
/
Vino
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Electrodos de Iones Selectos
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Metaloporfirinas
Idioma:
En
Revista:
Anal Chim Acta
Año:
2013
Tipo del documento:
Article
País de afiliación:
España