Calibration strategies for the direct determination of Ca, K, and Mg in commercial samples of powdered milk and solid dietary supplements using laser-induced breakdown spectroscopy (LIBS)

Autor(es)

Augusto, Amanda dos Santos ; Barsanelli, Paulo Lopes ; Verbi Pereira, Fabiola Manhas ; Pereira-Filho, Edenir Rodrigues

• Tipo de documento: Artigo Científico
• Fonte: Food Research International; v. 94, p. 72-78, APR 2017.
• Citações Web of Science: 23

Resumo

This study describes the application of laser-induced breakdown spectroscopy (LIBS) for the direct determination of Ca, K and Mg in powdered milk and solid dietary supplements. The following two calibration strategies were applied: (i) use of the samples to calculate calibration models (milk) and (ii) use of sample mixtures (supplements) to obtain a calibration curve. In both cases, reference values obtained from inductively coupled plasma optical emission spectroscopy (ICP OES) after acid digestion were used. The emission line selection from LIBS spectra was accomplished by analysing the regression coefficients of partial least squares (PLS) regression models, and wavelengths of 534.947, 766.490 and 285.213 nm were chosen for Ca, K and Mg, respectively. In the case of the determination of Ca in supplements, it was necessary to perform a dilution (10-fold) of the standards and samples to minimize matrix interference. The average accuracy for powdered milk ranged from 60% to 168% for Ca, 77% to 152% for K and 76% to 131% for Mg. In the case of dietary supplements, standard error of prediction (SEP) varied from 295 (Mg) to 3782 mg kg(-1) (Ca). The proposed method presented an analytical frequency of around 60 samples per hour and the step of sample manipulation was drastically reduced, with no generation of toxic chemical residues. (C) 2017 Elsevier Ltd. All rights reserved. (AU)

• Processo FAPESP: 14/11415-0 - Determinação de elementos essenciais e traços em suco de laranja e suplementos alimentares utilizando a técnica LIBS
• Beneficiário: Amanda dos Santos Augusto
• Modalidade de apoio: Bolsas no Brasil - Doutorado
• Processo FAPESP: 16/00779-6 - Obtenção direta de informações químicas de interesse comercial de matrizes analíticas sólidas diversificadas utilizando a espectroscopia de emissão com plasma induzido por laser (LIBS) e quimiometria
• Beneficiário: Hideko Yamanaka
• Modalidade de apoio: Auxílio à Pesquisa - Regular