Online sample preparation of milk samples for spectrophotometric determination of formaldehyde

Autor(es)

Costa, Naiara S. ; Maringolo, Vivian ; Brasil, Marcos A. S. ; Rocha, Diogo L. ; Melchert, Wanessa R.

• Tipo de documento: Artigo Científico
• Fonte: Journal of Food Composition and Analysis; v. 119, p. 7-pg., 2023-03-10.

Resumo

The chemical analysis of milk composition is important to detect the illegal use of preservatives such as form-aldehyde. Formaldehyde in milk is generally determined after microdistillation or protein precipitation steps. Commonly employed chromatographic methods for formaldehyde determination in milk generate high amounts of hazardous waste; however, the waste generation and reagent consumption can be easily minimized by non -chromatographic methods and sample processing in flow-based systems. In this work, a flow analysis system is proposed for online protein precipitation followed by continuous spectrophotometric determination of formaldehyde in milk. After precipitation with trichloroacetic acid and filtration, three portions of the extract were separately mixed with the colorimetric reagent. The detection limit was estimated at 0.45 mg L-1, which is lower than the recommended maximum content of formaldehyde in foods. After 51 determinations, the filtration unit was cleaned and was used for further analysis. Recoveries between 80% and 119% were obtained for whole milk, skimmed milk, and lactose-free whole milk sample that showed higher content of proteins owing to the presence of lactase. Herein, we propose a fast and reliable alternative for milk sample preparation and formal-dehyde determination. (AU)

• Processo FAPESP: 18/24029-1 - Tecnologias ambientalmente amigáveis no preparo de amostras de alimentos
• Beneficiário: Wanessa Melchert Mattos
• Modalidade de apoio: Auxílio à Pesquisa - Regular
• Processo FAPESP: 15/12172-6 - Procedimentos analíticos em fluxo com decomposições e extrações em linha para o fracionamento de espécies e determinações totais
• Beneficiário: Diogo Librandi da Rocha
• Modalidade de apoio: Auxílio à Pesquisa - Regular