Voltammetric Electronic Tongue for Discrimination of Milk Adulterated with Urea, Formaldehyde and Melamine

Autor(es)

Bueno, Ligia ; de Araujo, William R. ; Salles, Maiara O. ; Kussuda, Marcos Y. ; Paixao, Thiago R. L. C.

• Tipo de documento: Artigo Científico
• Fonte: CHEMOSENSORS; v. 2, n. 4, p. 16-pg., 2014-12-01.

Resumo

We report the fabrication of a voltammetric electronic tongue for the detection and discrimination of harmful substances intentionally added to milk to increase its shelf life or imitate protein content. The electronic tongue consisted of three working electrodes composed of platinum, gold, and copper. The measurement principles involved the extraction of information from cyclic voltammograms recorded in unadulterated and adulterated milk. The extracted data were analysed using principal component analysis and the contaminants were successfully differentiated from one another in a score plot. Electrochemical quartz crystal microbalance analysis was used to investigate the electrode response in order to understand the mechanism by which the tongue could discriminate between the samples. It was found that the electrochemical formation and dissolution of platinum and gold oxides, and the reduction of a copper-melamine ionic pair formed at the surface of the copper electrode were the main factors responsible for discrimination. In addition, the electronic tongue was capable of identifying adulterations in different types of milk (whole, skimmed, and semi-skimmed) and milk from different brands. The lowest concentration of adulterant that resulted in a good discrimination was 10.0, 4.16, and 0.95 mmol .L-1 for formaldehyde, urea, and melamine, respectively. (AU)

• Processo FAPESP: 12/12106-5 - Utilização de medidas eletroquímicas, colorimétricas e de massa para discriminação de amostras de interesse forense e alimentício utilizando dispositivos inteligentes (línguas e narizes eletrônicos)
• Beneficiário: Thiago Regis Longo Cesar da Paixão
• Modalidade de apoio: Auxílio à Pesquisa - Regular
• Processo FAPESP: 11/23355-3 - Estudo e fabricação de dispositivos inteligentes (línguas e narizes eletrônicos) visando à discriminação de contaminação em alimentos
• Beneficiário: Lígia Bueno Bedatty
• Modalidade de apoio: Bolsas no Brasil - Doutorado
• Processo FAPESP: 11/11115-8 - Desenvolvimento de língua híbrida (eletroquímica e colorimétrica) visando à discriminação de amostras forenses.
• Beneficiário: Maiara Oliveira Salles
• Modalidade de apoio: Bolsas no Brasil - Pós-Doutorado
• Processo FAPESP: 11/19903-5 - Desenvolvimento de métodos eletroanalíticos para detecção/discriminação de drogas de abuso, seus adulterantes e explosivos em amostras de interesse forense
• Beneficiário: William Reis de Araujo
• Modalidade de apoio: Bolsas no Brasil - Doutorado Direto