A new formaldehyde optical sensor: detecting milk adulteration

• Autor(a) principal: Veríssimo, Marta I. S.
• Data de Publicação: 2020
• Outros Autores: Fernandes, António J. S., Evtuguin, Dmitry V., Gomes, M. Teresa S. R., Gamelas, José A.F.
• Tipo de documento: Artigo
• Idioma: eng
• Título da fonte: Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos)
• Texto Completo: http://hdl.handle.net/10773/36672
• topic: Formaldehyde; Milk; Food adulteration; Optical fibre sensor; Polyoxometalate; Acetylacetone method

A sensor consisting of an optical fibre with the exposed tip coated with the polyoxometalate salt [(C4H9)4N]4H[PMo10V2O40], specially designed to be insoluble in water, which UV-Vis spectrum changed in contact with formaldehyde, is presented. The sensor limit of detection for formaldehyde was 0.2 mg L-1, and the limit of quantification was 0.6 mg L-1, which were close to the conventional spectrophotometric method values of 0.2 mg L-1 and 0.5 mg L-1, respectively, and lower than the tolerable limit for ingested food. The sensor was tested for formaldehyde quantification in milk, as its deliberate addition is a matter of concern. The results obtained analysing formaldehyde in milk samples by the optical sensor and by the conventional method were not statistically different (α = 0.05).