Voltammetric determination of sulfamethoxazole using commercial screen-printed carbon electrodes

A differential pulse voltammetric (DPV) method using commercial screen-printed carbon electrodes (SPCE) is developed for a fast and cost-effective determination of the antibiotic sulfamethoxazole (SMX). Optimal measurements are carried out at pH 5.5 in acetate buffer and yield a detection limit of 1...

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Detalles Bibliográficos
Autores: Alberto, Elena, Bastos-Arrieta, Julio, Pérez-Ràfols, Clara, Serrano, Núria, Diaz-Cruz, Silvia, Manuel Díaz-Cruz, José
Tipo de recurso: artículo
Estado:Versión publicada
Fecha de publicación:2023
País:España
Institución:Consejo Superior de Investigaciones Científicas (CSIC)
Repositorio:DIGITAL.CSIC. Repositorio Institucional del CSIC
OAI Identifier:oai:digital.csic.es:10261/332810
Acceso en línea:http://hdl.handle.net/10261/332810
https://api.elsevier.com/content/abstract/scopus_id/85165878677
Access Level:acceso abierto
Palabra clave:Sulfonamides
Antibiotics
Differential pulse voltammetry (DPV)
Metabolites
Screen-printed carbon electrode (SPCE)
Sulfamethoxazole (SMX)
http://metadata.un.org/sdg/3
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Descripción
Sumario:A differential pulse voltammetric (DPV) method using commercial screen-printed carbon electrodes (SPCE) is developed for a fast and cost-effective determination of the antibiotic sulfamethoxazole (SMX). Optimal measurements are carried out at pH 5.5 in acetate buffer and yield a detection limit of 15 µg/L and a linearity range of 50 – 600 µg/L with good repeatability (1.1%) and reproducibility (2.5%). The method is successfully applied to the analysis of a spiked tap water sample with very high reproducibility (0.4%) and good trueness (Recovery 95.2%). Additional considerations are made about the irreversible electrochemical oxidation of SMX, which is notoriously pH-dependent according to a process involving 2e- and 2H+, in agreement with several reported mechanisms in the literature. Besides, the analysis of other sulfonamide antibiotics is discussed, showing the key role of the free terminal amino group in oxidation, which makes almost undistinguishable voltammetric signals from different molecules sharing this moiety. In contrast, the acetylation of the mentioned group (e.g., in sulfonamide metabolites) drastically reduces the sensitivity of voltammetric measurements.