Hyperspectral images: a qualitative approach to evaluate the chemical profile distribution of Ca, K, Mg, Na and P in edible seeds employing laser-induced breakdown spectroscopy

Autor(es)

Gamela, Raimundo R. ^[1] ; Speranca, Marco A. ^[1] ; Andrade, Daniel F. ^[1] ; Pereira Filho, Edenir R. ^[1]

Afiliação do(s) autor(es)

^[1] Univ Fed Sao Carlos, Dept Chem, Grp Appl Instrumental Anal, POB 676, BR-13565905 Sao Carlos, SP - Brazil

• Tipo de documento: Artigo Científico
• Fonte: ANALYTICAL METHODS; v. 11, n. 43, p. 5543-5552, NOV 21 2019.
• Citações Web of Science: 1

Resumo

In the present study, laser-induced breakdown spectroscopy (LIBS) combined with chemometric tools was used to investigate the metal composition in nine seed samples. The samples were directly analyzed, and a matrix with 9 rows and 9 columns (81 points) and 10 consecutive pulses were analyzed in each point. A total of 810 emission spectra were collected from 186 to 1042 nm from the surface and bulk of the sample. The dataset was normalized by Euclidian norm and principal component analysis (PCA) was used for the initial exploratory investigation. Calcium, Mg, Na, K and P were mainly identified in all samples; however, the distribution of metals in these samples is not completely homogeneous, i.e., the composition of the elements change from one layer to another. This fact can be probably related to the absorption capability of nutrients resulting from different factors such as soil characteristics, physiology of the plant, water source composition and fertilizers which can influence the distribution of the elements in different seeds. To confirm the elements observed by LIBS, the samples were digested using microwave-assisted digestion, and Ca, K, Mg, Na and P were determined by inductively coupled plasma-optical emission spectrometry (ICP-OES). In addition, some minor nutrients such as S and Zn were also investigated and the relationships between elements were observed through the Pearson correlation graph, and some of them, such as Mg and Na, P and Na, S and P, S and Zn, are extremely correlated; it means that, for example, when the concentration of Mg increases, that of Na also increases. (AU)

• Processo FAPESP: 16/17304-0 - Proposição de métodos para a análise direta de amostras de lixo eletrônico: determinação de elementos preciosos, estratégicos e tóxicos em circuitos eletrônicos e telas touch screen
• Beneficiário: Daniel Fernandes de Andrade
• Modalidade de apoio: Bolsas no Brasil - Doutorado
• Processo FAPESP: 16/01513-0 - Combinação de LIBS (Laser-Induced Breakdown Spectroscopy) e ICP OES (Inductively Coupled Plasma Optical Emission Spectrometry) na análise de amostras de resíduo eletrônico (circuito eletrônico e polímeros), alimentos e líquidas de difícil preparação
• Beneficiário: Edenir Rodrigues Pereira Filho
• Modalidade de apoio: Auxílio à Pesquisa - Regular